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  • IPEN-DOC 28973

    ANDRADE, IZABEL da S. ; ARAUJO, ELAINE C. ; CORREA, THAIS ; MACEDO, FERNANDA de M ; LANDULFO, EDUARDO . Spatial-temporal analysis of NO2 in the Metropolitan Region of São Paulo. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 68-68.

    Abstract: Nowadays, several methods of monitoring air pollutants exist, however few allow a large spatial and temporal coverage. Sentinel-5P is a satellite dedicated to atmospheric monitoring with a high spatial-temporal resolution, offering a large data of miscellaneous chemical species. Nitrogen oxides (NO and NO2), emitted by anthropogenic activities into the atmosphere - in large urban centers their main emitting source is vehicles - need particular attention, , in addition to being primary pollutants, they are precursors for formation of other chemical species due to photochemical reactions, mainly tropospheric ozone. These photochemical interactions of NOX stimulate to reduce its lifetime in the atmosphere. Furthermore, these pollutants are used as air quality indexes. The Metropolitan Region of São Paulo (MRSP) has more than 30 cities, being an important economic center for the state of São Paulo. The MRSP has highways with high circulation of light and heavy vehicles, industries and also a high population density. Such factors make this region a favorable area for a satellite study. Thus, the present work uses Sentinel-5P NO2 L2 data in order to analyze the evolution of concentrations throughout 2019.

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  • IPEN-DOC 28972

    PALLOTTA, JUAN; LOPES, FABIO ; BARBOSA, HENRIQUE M.J.; CARVALHO, SILVANIA A.; CACHEFFO, ALEXANDRE; LANDULFO, EDUARDO . Collaborative development of a Lidar Processing Pipeline. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 52-52.

    Abstract: Aerosols, clouds and their interactions are the source of the largest uncertainties in current climate change estimates. More frequent and higher quality measurement of aerosol, clouds, and the physical processes governing their link with climate are needed to reduce these uncertainties, and lidars are a powerful instrument to accomplish this task. However, lidars are generally developed by individual groups for particular applications, and hence typically have very different characteristics. In this sense, lidar networks play a key role as they coordinate the efforts of different groups, providing the guidelines for quality-assured routine measurements on a regional scale. Moreover, a coordinated effort is of utmost importance to homogenize the physical retrievals from the highly non-uniform instruments in a network. This is only possible with the development of a unified processing pipeline that accounts for the hardware heterogeneity in the pool of instruments. Here, we describe an ongoing effort to collaboratively develop a Lidar Processing Pipeline. The LPP is a collection of tools developed in C++ and Python that are planned to handle all the steps of lidar analysis. A first tool converts the raw data files into a single NetCDF file, including detailed information about the instrument and acquisition setup (Level 0 dataset). . Then, this is processed by another tool which applies the necessary corrections and computes the cloud-mask (Level 1 dataset). The final step is the elastic and/or inelastic retrieval of aerosol properties (Level 2 dataset). The development of LPP has been based on the existing analysis routines developed by individual groups, and hence takes advantage of previous efforts for algorithm comparison in the scope of Lalinet Network. A general concept and first steps of the ongoing project are reported, as well as the next steps towards the release of the first operational version of the processing pipeline.

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  • IPEN-DOC 28971

    CORREA, THAIS ; MACEDO, FERNANDA M. ; ARAUJO, ELAINE C. ; ANDRADE, IZABEL S. ; GOMES, ANTONIO A. ; SILVA, JONATAN ; LANDULFO, EDUARDO . Methane determination in São Paulo coastal regions using the Cavity Ring-Down Spectroscopy (CRDS) technique. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 50-50.

    Abstract: Methane is one of the main greenhouse gases due to its high radiation absorption capacity. The increase in methane emissions from anthropogenic sources causes concern in the entire scientific community due to the aggregated uncertainties, generating several works focused on the identification and quantification of generating sources. This work aims to quantify methane in two distinct regions, the first study region is in Cubatão city, located in the São Paulo coast. It is an important petrochemical complex with high industrial activities and environmental impact, presenting 25 large companies in the chemical sector, distributed in an area of 143 Km2. Another region observed is Intanhaém, on the coast of the state of São Paulo. This region doesn´t present industrial activity and has a low population index. The technique used to detect methane in the atmosphere was Cavity ring-down spectroscopy (CRDS), which consists on analysis of atmospheric components, in a small cavity that has a laser and high reflectivity mirrors of 99.999%, allowing the signal travel for kilometers inside the cavity, in a short time, increasing the sensitivity of detection of compounds in the sample.

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  • IPEN-DOC 28970

    MACEDO, FERNANDA M. ; LANDULFO, EDUARDO . Use of SNOM for analysis of biomarker molecules when excited by Raman. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 27-27.

    Abstract: During the last decade, many studies have made significant progress in understanding the causes and implications of our environment, with respect to the atmosphere. Bioaerosols are fundamental in the reproduction of plants and microorganisms (pollen, spores, etc.), which in the atmosphere are transported across borders and long distances. For this reason, bioaerosols have great importance in genetic diffusion between habitats and biomas geographic change, contributing as main elements in the development, evolution and ecosystems dynamics. The consequences related to public health and agriculture are associated by the dispersion of plants, animals, pathogens and human allergens, showed an increase of allergies and asthma cases during storms, due to high concentrations of bioaerosols, especially when attributed to fungal spores. The biological content found in the air of global land surfaces corresponds to a quarter of the total particles found in the air, consisting mainly of proteins, arising from pollens, fungal spores, bacteria, viruses or fragments of plant or animal matter. Some proteins act as marker molecules which autofluoresce if excited at a specific wavelength. A signature of biomarker proteins, existing in the cell wall of fungal spores of medical interest, will be developed using scanning near-field optical microscopy (SNOM). This new high resolution optical methodology will allow detailed analysis of biomarker molecules (ergosterol, mannitol and arabitol), as well as their behavior when excited by Raman. In possession of a molecular standard, a database of these characteristics will be created, which will provide technical support for the remote Raman sensing of these species in the atmosphere of the Metropolitan Region of São Paulo (MRSP).

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  • IPEN-DOC 28969

    SOUZA, GIOVANNI ; LOPES, FABIO J.S. ; LANDULFO, EDUARDO . Study of optical properties and spatial distribution of cirrus clouds over São Paulo, Brazil, using CALIPSO level 2 data. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 67-67.

    Abstract: Cirrus clouds have an important role in the earth’s radiation budget, they have a wide spatial extension and are the most present type of clouds in the atmosphere, especially in tropical regions (Sassen et al., 2018). Due their thickness, Cirrus clouds are almost transparent for the incoming shortwave solar radiation and opaque to the longwave emitted by the planet's surface. Despite the importance of Cirrus clouds in the earth’s climate, there is a lack of studies focused on this type of cloud in the southern hemisphere. Since 2006, the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), a joint mission between NASA and the French space agency, CNES, provides physical and optical information of clouds and aerosols to improve the understanding of their role in the climate, air quality and radiation budget in the Earth. The primary instrument of CALIPSO payload is the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), which is a lidar system operating on 1064 nm and 532 nm (with parallel and perpendicular polarization) wavelengths. CALIOP provides as level 1 data, high-resolution vertical profiles of aerosols and clouds. In turn, the level 2 data provides processed products such as cloud-aersol discrimination, cloud base and top layer altitude, and cloud optical depth. The aim of this work is use the CALIOP global coverage to study the physical and optical properties of Cirrus clouds over the São Paulo State (roughly centered on 21.3°S, 50.3°W), in Brazil. We have employed a statistic analysis of 9 years (2007-2015) of data using the level 2 products to obtain spatial distribution and optical properties of cirrus clouds over São Paulo state, in order to understanding the long-term trend of Cirrus clouds coverage in the São Paulo state and later on Brazil.

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  • IPEN-DOC 28968

    MEDEIROS, PEDRO A. ; MARQUES, MARCIA; LANDULFO, EDUARDO . Limits of a prediction model using RNN with four layers LSTM for CRDS data. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 57-57.

    Abstract: Prediction models can be very useful when dealing with ciclic temporal sequence of data. For ciclic sequences that have caotic behavior, like atmospherics measures, the Recurrent Neural Network(RNN) is a potential option to create acurate prediction models.This type of neural network is effective in dealing with temporal sequences because it uses its internal state as a memory to process certain data intervals. In building the model, it is necessary to use layers with neurons to discern a trend that the data sequence takes, for this, in the RNN model it is possible to use the long short-term memory (LSTM) architecture to more easily predict unusual behaviors in the data stream, since its use facilitates the recognition of long-term sequences in the analyzed sequence. This type of architecture can be added in layers to increase model efficiency. For the training and testing of the model, data obtained by the Metroclima project with a Cavity Ring Down Spectroscopy (CRDS) at the UNICID station located in São Paulo were used, with the data ranging from 2019 to 2021. In this process, four LSTM layers will be used to create a prediction model that will be tested to its limit on the effectiveness of predicting atmospheric data of this type.

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  • IPEN-DOC 28967

    ARAUJO, ELAINE C. ; ANDRADE, IZABEL da S. ; MACEDO, FERNANDA de M. ; CORREA, THAIS ; LANDULFO, EDUARDO . Preliminary study of greenhouse gases in the Santos Basin. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 49-49.

    Abstract: The production of oil and gas onshore and offshore are associated with significant emissions of greenhouse gases, as the entire production chain of oil exploration is a potential source of emission of these gases, especially CH4, which is in almost all stages of the process However, few data is available on emissions from oil exploration platforms in Brazil, despite the increase in oil production on the Brazilian coast since 2008 with the implementation of the Pre-Salt program, which aims to explore oil in the pre-salt layer. Between the explored areas is the Santos Basin which occupies about 350,000 km2 and is located in the southeast region of the Brazilian continental margin, approximately 290 km off the coast of Rio de Janeiro and encompasses the coastlines of the States of Rio de Janeiro, São Paulo , Paraná and Santa Catarina, with boundaries to the north with the Campos Basin by the Alto de Cabo Frio and to the south by the Pelotas Basin by the Florianópolis Platform. Better understanding the ocean-atmosphere interactions in the Santos Basin region, specifically in the coastal area of São Paulo, a temporal analysis was performed using data from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument, which provides data on active burning and from Sentinel-5P (Sentinel 5 Precursor satellite) which brings information from several chemical species, such as NO2 and CH4.

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  • IPEN-DOC 28966

    SILVA, THAIS A. da ; OLIVEIRA, CARLOS E.S. de; CRUZ, DANILO D.; MEDEIROS, ILCA M.M.A. ; MEDEIROS, JOSE A.G. de ; OLIVEIRA, LUCAS P.; MARQUES, MARCIA T.A.; MEDEIROS, PEDRO A. ; ANDRADE, MARIA F.; LANDULFO, EDUARDO . Measurement of greenhouses gases in the city of Sao Paulo: assessing methane concentrations and sources. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 48-48.

    Abstract: The gases that most contribute to the greenhouse effect are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). When those gases have been in the atmosphere for a long time, its effects become almost irreversible with the radiative forcing of years, until natural processes manage to remove the quantities already emitted. Methane is a radiative agent and happens significantly in the southern hemisphere. Methane is a major source of water vapor. When the concentration of water vapor in the stratosphere increases, it contributes to intensifying the greenhouse effect. The large part of carbon dioxide and methane absorbed by the ocean, atmosphere and biosphere, contributes to the global carbon cycle, bringing a stable carbon rate in the air. Forest fires are often responsible for releasing carbon dioxide and methane. It is important to consider the role of photosynthesis in the balance between anthropogenic process, climate change and air quality. Therefore, forest preservation and reforestation projects are fundamental against climate change. The main purpose of Metroclima Project is to assess the sources of greenhouse gases and short-lived pollutants in Sao Paulo and neighboring cities, in the Southeast of Brazil. Currently, the GHG measurement network has four stations (IAG Station, Pico do Jaragua, UNICID and ICESP) extended across the City of Sao Paulo, measuring carbon dioxide and methane concentrations continuously using Cavity Ring Down Spectroscopy (CRDS) instruments. In specific, the goal of this study is related to assessment of methane concentration variability and identification of potential sources near UNICID Station – an urban site; using the CRDS Picarro G2401 system. The data analysis acquired during 2020 and 2021 will be shown. Our results comprise a valuable contribution to the knowledge about methane concentrations in the city and guide public decision based on scientific evidence.

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  • IPEN-DOC 28965

    ANTUNA-MARRERO, JUAN C.; ARREDONDO, RENE E.; LANDULFO, EDUARDO ; VEGA, ALBETH R.; SANCHEZ, JUAN C.A.. Extending LALINET observations to the Upper Troposphere and Lower Stratosphere (UTLS): a challenge in the post-COVID-19 era. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 36-36.

    Abstract: By the end of the XX century the lack of resources in the Latin America was not an obstacle to create the Latin America Lidar Network (LALINET). The strategy to build LALINET was to create first a lidar community in the region from the few lidar teams (mainly measuring in the troposphere). A little more than two decades later LALINET resilience will be tested by the post-COVID-19 era. In Latin America the economic crisis resulting from the COVID-19 health crisis will reduce notably funds for many activities, including scientific research. LALINET contingency strategy (to be discussed and approved at the XI WLMLA) has as its main goal to maintain the level of tropospheric aerosols observations and research activities reached during the last decade. However, the contingency strategy has several other goals, including extending LALINET observations to the UTLS making use of the existing lidar facilities. We have been setting up progressively a program for UTLS regular measurements, making use of the existing lidar facilities. It consist in four main steps: 1) Lidars currently retrieving tropospheric aerosols profiles will be tested for its signal to noise ratios in the region of the UTLS to determine if its current characteristics allows retrieving aerosol backscatter profiles in that region; 2) designing the algorithm to be used and implement the version 1 of LALINET standard software/scripts to produce UTLS aerosol backscatter and extinction profiles; 3) implement the processing of UTLS observations at each site having that capabilities; 4) conduct the processing of all the stored profiles at those sites. Several studies on stratospheric aerosols conducted in the region and abroad have accumulated know-how that is being and will be applied to the retrieval of UTLS aerosols lidar backscattering and extinction profiles at LALINET sites. The presentations will show and discuss those studies and also describe the current status of the four steps listed above.

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  • IPEN-DOC 28964

    CARVALHO, SILVANIA A.; LOPES, FABIO J.S. ; SILVA, JONATAN J. da ; MENEGATTI, CARLOS R.; CATALANI, FERNANDO; TODERO, CARLOS J.; RIBEIRO, FABIO de J.; ALMEIDA, ROGERIO M. de; LANDULFO, EDUARDO . LIDAR first campaign in the industrial sites of Volta Redonda-RJ and Lorena-SP, Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 29-29.

    Abstract: Air pollution is recognized as a risk factor for health. The emission of toxic gases and particulates, specially with diameter size smaller than 10 μm, into the atmosphere by industries is correlated with increasing respiratory problems, mortality and cancer in some urban areas. Additionally the aerosol particles play an important role in the Earth’s radiation budget and the understanding of their properties is important to address their effects on the climate and weather conditions. In this study we will present some results of aerosol vertical distribution retrieved using a mobile lidar system and the lidar system on board of the CALIPSO satellite platform. The synergetic use of these platforms helped to understand the impact of the aerosol suspended in the atmosphere in terms of its optical properties in two different sites between two main metropolitan areas of Brazil, which are São Paulo and Rio de Janeiro. In order to obtain a statistical characterization of the aerosol optical properties, level 2-version 4 data from CALIPSO were employed to retrieve the AOD and Lidar ratio values at 532 nm for Volta Redonda and Lorena sites. Lorena campaign was performed during a very dry period in the 2014 Southern hemisphere winter, where it detected the vertical distribution profile with several layers detached from the aerosol boundary layer (ABL) on 26th of June 2014. Volta Redonda-RJ campaign performed from the beginning of November until mid of December of 2018 provided detection of aerosol layers detached from ABL on 4th of December of 2018. We will present a brief description of the experimental apparatus, the data taking, the methodology and the main results which open up the possibility to investigate emission of toxic gases and particulates at this region which has high contribution to local atmospheric pollution due to the Presidente Dutra highway (BR 116), the Companhia Siderúgica Nacional (CSN) and other metallurgical and cement factories.

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  • IPEN-DOC 28963

    MORAIS, FERNANDO G. ; FRANCO, MARCO A.; BARBOSA, HENRIQUE M.J.; JORGE, FABIO; ARTAXO, PAULO; LANDULFO, EDUARDO . Seasonal analysis of Brown Carbon, Black Carbon and Dust at Central Amazonia with Ångström Matrices. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 24-24.

    Abstract: Aerosol optical properties are an important and direct way to understand and quantify the seasonal effects of the Amazonian aerosol by means of the intensive optical properties: absorption and scattering Ångström exponent. AERONET photometers measure the aerosol optical properties and associated with a set of algorithms, obtain information of the aerosol physical characteristics such as the aerosol optical depth (AOD) and the absorption aerosol optical depth (AAOD) almost in real time. For the last 22 years, those properties have been measured at several AERONET sites using CIMEL sun photometers in Amazon. Measurements were done in Central Amazonia (Manaus and ATTO tower), as well as in the deforestation arc: Rio Branco, Cuiabá, Ji-Paraná, and Alta Floresta, and results have shown important geographical and seasonal variability in terms of aerosol impacts. We can access the seasonal Brown Carbon, Black Carbon, and Dust calculating the Ångström matrix with absorption and scattering Ångström exponent. We observe a clear separation between dry and wet season, and in the later, also a period in which Dust comes from Saara (mostly between January to April). Therefore, it was possible to observe Brown Carbon (BrC) in addition to Black Carbon (BC), which is responsible for 12% of the AAOD of aerosols at 440nm in the deforestation arc in sites that are about 1000 km apart and show consistency very good. As for pristine sites, such as the ATTO site, the contribution of BrC is 25% in relation to the AAOD at 440nm where we have very little human interference.

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  • IPEN-DOC 28962

    SANTOS, AMANDA V. ; LANDULFO, EDUARDO ; MOREIRA, GREGORI A. ; MARQUES, MARCIA T.A.; ANDRADE, MARIA F.. Comparing lidar and ceilometer backscattering measurements for the detection of aerosol layers in the PBL over São Paulo, Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 22-22.

    Abstract: The Planetary Boundary Layer (PBL) is the lowest part of the troposphere and it is directly influenced by the Earth’s surface and anthropogenic activities. The concentration of aerosol in the PBL is typically much higher than in the free troposphere. Given that most of the air pollution in the troposphere is capped by this layer, obtaining the PBL height (PBLH) and its evolution during the day can assist in monitoring and studying aerosol concentrations and properties and its impact on air quality. Multi-instrument monitoring of the PBLH can assist in identifying the arrival of different air masses and tracking the evolution of aerosol layers during the day. Due to their lower cost, ceilometers can be powerful tools to enhance these measurements, although such an instrument has a few limitations when compared to lidars. The weaker laser light source used in ceilometers can limit the detection of aerosol layers to a few kilometers in height, depending on the presence and distribution of clouds and aerosols in the atmosphere. Given that some methods to estimate the PBLH need strong gradients in the concentration of aerosols to identify it correctly, the improper identification of the aerosol layers can become problematic for obtaining the PBLH. We compared lidar and ceilometer data from two instruments located in the city of São Paulo, Brazil, approximately 15 km from each other. We found that, in clear sky conditions, it is possible to correctly identify aerosol layers in the PBL with data from both instruments. The presence of clouds, signal attenuation and noise can sometimes cause errors in the identification of aerosol layers, especially when using ceilometer data. We found that, despite not being co-located, both instruments show similar profiles, up to a few kilometers in height.

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  • IPEN-DOC 28961

    JESUS, ESTER O. de ; ROSARIO, NILTON M.E. do; YOSHIDA, ALEXANDRE C. ; CACHEFFO, ALEXANDRE ; GUERRERO-RASCADO, JUAN L.; LANDULFO, EDUARDO ; LOPES, FABIO J.S. . Study of aerosol optical properties on South America using AERONET data analysis: preparation for EARTHCare ESA Satellite mission. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 21-21.

    Abstract: In the last decade, a new generation of satellite missions have been developed using advanced lidar systems capable to retrieve several cloud and aerosol optical properties and distinguish different aerosol types by applying a polarization sensitive high spectral resolution lidar (HSRL) technique, as is the case of the Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) mission, developed by the European Space Agency (ESA) together with the Japan Aerospace Exploration Agency (JAXA). The EarthCARE payload will be compound by four main instruments, a cloud profiling radar, with Doppler capability, the HSRL system, a multispectral imager and a broadband radiometer, enabling the retrieval of global profiles of clouds, aerosols, precipitation and radiation field properties. The Atmospheric Lidar system (ATLID) on board of EarthCARE will operate at 355 nm and will use the cross and co-polarized components of Mie and Rayleigh scattering to derive aerosol properties. An important task to be developed by ground-based research groups is the data validation process. In this context, the Latin American LIdar NETwork (LALINET) has been playing a key role in the cloud and aerosol studies by using lidar and/or the AERONET sunphotometers data. In order to prepare the most suitable strategy for calibration and validation (CAL/VAL) processes of the EarthCARE mission, we have employed an extensive study of aerosol optical properties derived from 21 AERONET sunphotometer stations all over South America, from a period of at least 20 year. The aim of this work is to present preliminary results of columnar aerosol optical properties, such as AOD, lidar ratio, scattering and absorption Angstrom Exponent, single-scaterring albedo and aerosol fine-mode fraction, in order to select cluster-zones by aerosol types to guide the validation methodology for ATLID system products, since the continent is dominated by high spatial and temporal variability of aerosol systems.

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  • IPEN-DOC 28960

    LOPES, PEROLA P.Q. ; LOPES, FABIO J.S. ; LANDULFO, EDUARDO . Study between atmospheric paramenters and pyranometer global radiation measurements at São Paulo, Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 11th, October 19-22, 2021, Punta Arenas, Chile. Abstract... Punta Arenas, Chile: Universidad de Magallanes, 2021. p. 19-19.

    Abstract: According to the recently released report of the Intergovernmental Panel on Climate Change (IPCC) on August of 2021, the well-mixed greenhouse gas (GHG) concentrations have continued to increase in the atmosphere, reaching annual averages of 410 ppm for CO2,1866 ppb for CH4, and 332 ppb for N2O. The GHGs can contribute to warming the atmosphere up to 2.0°C, while aerosols can contribute to cooling up to 0.8°C. in this context, it is increasingly important to monitor the global solar radiation flux incident on the atmosphere. The pyranometer instrument is designed to measure the solar radiation flux density (W/m2) and it can be used to get information about the amount of radiation incident on the ground and how much of this radiation is absorbed or scattered. The aim of this work is to show preliminary results retrieved by Piranometer installed in the SPU Lidar Station, in São Paulo-Brazil, and how the global solar radiation can be correlated with other atmospheric parameters retrieved from AERONET sunphotometer and meteorologic stations, such as the aerosol optical depth (AOD), cloud cover, relative humidity, in order to quantify the aerosol influence in the process of atmospheric radiation and climate change.

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  • IPEN-DOC 28959

    CASTRO, P. ; PEREIRA, D. ; ANA, P.; MATOS, C.; ZEZELL, D. . Q-switched Nd:YAG laser on dental enamel with photoabsorber: a confocal Raman pilot study. In: VIRTUAL RAMAN IMAGING POSTER SUMMIT, 1st; INTERNATIONAL CONFERENCE FOR CHEMICAL CHARACTERIZATION & IMAGING, September 28 - October 2, 2020, Online. Abstract... Ulm, Germany: WITec, 2020. p. 33-33.

    Abstract: Nd:YAG lasers emitting λ = 1064 nm at microsecond and nanosecond pulses are alternatives to prevent dental caries and erosion in clinics. This wavelength allows most of photons to penetrate deep in the hard tissue due to low absorption of hydroxyapatite in the region. It is necessary to use photoabsorbers so most of photons are absorbed in the surface of the tissue preventing dental pulp necrosis. Currently the coal paste is used as a photoabsorber but the irradiated tissue turns darker what implies in the patients low adherence to the treatment due to aesthetic reasons. [1,2]. Confocal Raman spectroscopy is a non-destructive optical method to obtain detailed information about molecular composition of biological structures in depth. The most prominent feature of Confocal Raman spectroscopy is the reliable capability to provide the biomolecular data with no use of ionizing radiation to penetrate in the sample. This work aims to characterize the dental enamel irradiated with Nd:YAG laser with nanoseconds pulses, in order to describe the depth related changes promoted in the enamel, by the heat generated due to laser irradiation. For these measurements, 30 bovine enamel blocks of 8 mm2, were randomized into 3 groups: G1 – enamel untreated; G2 – enamel irradiated with Nd:YAG nanopulsed laser (1064 nm, 4 W; 1,05 J/cm2; 5 ns 20 Hz, Brilliant, Quantel Laser) using a coal paste as photoabsorber; G3 -enamel irradiated with Nd:YAG nanopulsed laser ( same parameters as G2) using squid ink as photoabsorber. The assessments of three different depth regions of the cubic shaped samples were: region A- left corner above of the sample, region B-middle of the sample and Region C- right corner below of the sample. The intensity map of phosphate (950 cm-1) regarding the position, were calculated [3,4] as shown in the Figure 01. The comparative results in the Fig.1 demonstrated that application of coal paste associated with Nd:YAG (G2) can preserve the inorganic content better than the squid ink group (G3). These findings have crucial clinical implications in the laser protocol development and it was possible to correlate the heat penetration depth of the laser irradiation with photoabsorber using the images obtained by the confocal Raman.

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  • IPEN-DOC 28958

    D'AGOSTINO, GIANCARLO; BLAAUW, MENNO; DUNG, HO M.; LUZIO, MARCO di; JACIMOVIC, RADOJKO; DIAS, MAURO da S. ; SEMMLER, RENATO ; SLUIJS, ROBBERT van; BARRADAS, NUNO P.. The 2021 IAEA software intercomparison for k0-INAA. In: INTERNATIONAL k0-USERS’ WORKSHOP, 8th, June 6-10, 2022, Ljubljana, Slovenia. Abstract... Ljubljana, Slovenia: Institut "Jožef Stefan", 2022. p. 17-17.

    Abstract: In order to establish the variation between results due to software implementation in mass fractions as measured by the k0-method for INAA, the IAEA has organized a software intercomparison. A complete set of test spectra and associated information was assembled. Efficiency curves, neutron spectrum parameters, correction factors and mass fractions were calculated with the participating programs (list of program names here) using identical peak areas. In this paper, we report on the observed discrepancies, causes, remedies and future software developments. The test data, as well as expected and certified mass fractions of the BCR-320R channel sediment sample material will be made available to all.

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  • IPEN-DOC 28957

    DIAS, MAURO da S. ; SEMMLER, RENATO ; KOSKINAS, MARINA F. ; MOREIRA, DENISE S. ; YAMAZAKI, IONE M. ; BRANCACCIO, FRANCO ; BARROS, LIVIA F. ; RIBEIRO, RAFAEL V. ; MORAIS, THALES S.L. de . k0-IPEN / a new software for Instrumental Neutron Activation Analysis. In: INTERNATIONAL k0-USERS’ WORKSHOP, 8th, June 6-10, 2022, Ljubljana, Slovenia. Abstract... Ljubljana, Slovenia: Institut "Jožef Stefan", 2022. p. 16-16.

    Abstract: A new software package for INAA, developed at the Nuclear Metrology Laboratory (LMN) of the Nuclear and Energy Research Institute (IPEN-CNEN/SP), called k0-IPEN, is described. The package consists of a main program linked to nine subprograms designed to perform automatically all the tasks necessary in order to obtain the mass fractions of the irradiated samples. The goals of these nine routines are: a) to calculate the experimental peak efficiencies and P/T ratios for the standard sources, together with all the corresponding uncertainties; b) to correct the peak efficiencies for coincidence summing; c) to fit the peak efficiencies and P/T ratios with log-log polynomial functions; d) to determine experimentally the  and f parameters by the Triple Bare and by the Cd Ratio Multimonitor Methods; e) to correct for interferences; f) to determine the average mass fractions, taking into account the correlations among all partial uncertainties involved. In the present version, the only data that must be inserted as input parameter, externally from the package, are the self-shielding correction factor, which is calculated by the MATSSF code, and the geometry factor that corrects for the difference between sizes of standard sources and measured samples. The code can deal with different spectrum formats such as CHN, SPE and CNF. The routine designed to calculate the peak areas has a simple algorithm and is not yet capable of separating multiplets. Therefore, it is suitable for analysing separated peaks, such as those found in standard calibration source measurements. However, for complex spectra, the code can read peak list files obtained from other codes, such as HyperMet or HyperLab. External efficiency curves calculated by the Monte Carlo code MCNP6 can be read to extend the calibration curve to regions where there are only a few experimental points available. The code k0-IPEN is being tested and its validation accomplished by means of an intercomparison sponsored by the IAEA, and presented at this conference.

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  • IPEN-DOC 28908

    BASSO, LUANA; GATTI, LUCIANA ; MARANI, LUCIANO; MILLER, JOHN; GLOOR, MANUEL; MELACK, JOHN; CASSOL, HENRIQUE; TEJADA, GRACIELA; DOMINGUES, LUCAS ; ARAI, EGIDIO; SANCHEZ, ALBER; CORREA, SERGIO; ANDERSON, LIANA; ARAGAO, LUIZ; CORREIA, CAIO ; CRISPIM, STEPHANIE; NEVES, RAIANE. Regional variability in Amazon methane emissions based on lower-troposphere observations. In: EGU General Assembly, May 23-27, 2022, Vienna, Austria. Abstract... Göttingen, Germany: Copernicus, 2022.

    Abstract: After a period where atmospheric methane (CH4) levels were nearly steady, its levels have been rapidly raising since 2007, but the main reasons remains uncertain. Increases in wetlands emissions could be one possible reason, mainly at tropical regions like Amazonia, which host some of the largest wetlands/seasonally flooded areas on the globe. Based on 590 lower troposphere vertical profiles of CH4 and carbon monoxide (CO) observations over four sites at Amazon (at the northeast, southeast, northwest-central and southwest-central regions) we estimated that Amazon region contributes with 8% of global CH4 emissions, and wetlands are the mainly CH4 source to the atmosphere (Basso et al., 2021). Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and CO analysis of flask air, fortnightly between 2010 and 2018. We observed an unexpected east-west gradient in CH4 emissions, with higher emissions in northeast Amazon region. The higher emissions are mainly from wetlands and are not explained by biomass burning and anthropogenic emissions (like enteric fermentation), but its causes remains unclear. In the other three sites located further downwind along the main air-stream the CH4 emissions represents approximately 24-36% of what is observed in the northeast region. Our wetlands emission estimates of each region were compared to analogous fluxes from the WetCharts wetland model ensemble (Bloom et al., 2017). The estimates were similar except for the northeast region, where WetCharts does show substantial emissions, but still just 40% of our estimates based on the lower troposphere observations (Basso et al., 2021).

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  • IPEN-DOC 28907

    TEJADA, GRACIELA; GATTI, LUCIANA V. ; BASSO, LUANA S.; MATAVELI, GUILHERME A.V.; CASSOL, HENRIQUE L.G.; VON RANDOW, CELSO. Forest biomass: an uncertainty source of land use and land cover change related carbon emissions in the Amazon. In: EGU General Assembly, May 23-27, 2022, Vienna, Austria. Abstract... Göttingen, Germany: Copernicus, 2022.

    Abstract: Tropical forest plays a fundamental role in the ecosystem services maintenance. Amazon forests have been subject to intense land use and cover changes (LUCC), mainly in the Southeast portion. Like many tropical countries, more than 70% of Brazilian greenhouse gasses emissions come from LUCC. Under the framework of the CARBAM Project, atmospheric CO2 measurements in four sites of the Amazon, show that there is a reduction in the Amazon forest capacity to absorb C in the proximities of previous deforested and degraded forest areas, such as the well-known “Deforestation Arc” in the Southeast amazon. There are many LUCC databases now available that allow to assess the deforestation, degradation and second forest dynamics and contribute to a better understanding of the carbon dynamics of nine years of in situ atmospheric CO2 measurements. Nevertheless, in order to know how much CO2 is released to the atmosphere due to LUCC, it is necessary to quantify how much carbon is stored in the forest biomass and to assess the biomass variability along the different datasets. Here we compared the forest biomass quantity of three biomass maps: the fourth national communication of Brazil map (official), a global map (Baccini et al. 2012) and a regional map for the Brazilian Amazon (EBA project). We found significant differences for the Brazilian Amazon: between the official biomass map and the regional map 27%, between the global and regional map 25% and the smallest difference was between the official and the global map (3%). Even though the official and the regional maps were obtained using the same data inputs, the official map refers to a potential biomass for 2010 and the regional map reflects the real biomass in 2016, this could explain the difference. The official and global maps represent the potential biomass, and as we used the mean forest area, the biomass content is similar. When comparing these maps at a deforested pixel level the differences could be larger. The spatial and temporal scale of biomass maps make it hard to estimate the CO2 emissions of degradation and secondary forest loss and growth which are fundamental to understand the Amazon C balance under climate change and LUCC pressures.

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  • IPEN-DOC 28901

    SILVA, CAMILA R. ; PEREIRA, SAULO T. ; CONTATORI, CAROLINA G.S. ; PINTO, MAYARA S. ; SALVEGO, CAMILA A. ; RIBEIRO, MARTHA S. . Efeitos da fotobiomodulação pré-exposição à radiação ionizante em células de câncer de mama. In: FÓRUM ON-LINE DE TECNOLOGIAS DA LUZ NA SAÚDE, 2nd, May 20-22, 2021, Online. Resumo expandido... Campinas, SP: Faculdade São Leopoldo Mandic, 2021.

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  • IPEN-DOC 28900

    VIVEIROS, BARBARA V.G. de ; BERBEL, LARISSA O. ; DONATUS, UYIME ; COSTA, ISOLDA . The corrosion behavior on AA2050-T84 and AA7050-T7451 welded and non-welded by FSW. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: In this work, the corrosion resistance of the AA2050-T84 and AA7050-T7451 alloys welded by FSW and non-welded was investigated using chloride solutions. The corrosion resistance, microstructure and microhardness were studied. Microhardness measurements at the cross section and at the top surface of the weld identified significant differences between the various zones resulting from FSW. Characterization of the corrosion resistance was carried out by electrochemical and immersion tests. Localized electrochemical techniques were used in this work, specifically scanning vibrating electrode technique (SVET) and scanning ion-selective electrode technique (SIET). The results showed that the most electrochemically active zone at of the welded alloys was the thermomechanically affected zone (TMAZ). This zone corresponds to the transition between the two alloys. In the top surface of the welded alloys, besides the TMAZ, the heat affected zone (HAZ) was also highly active corresponding to the transition between zones of the AA7050. This was due to the formation of hardening precipitates in the HAZ of the AA7050. In the cross-section, the high activity related to the TMAZ was due to the galvanic coupling between the two alloys where the AA7050 alloy acted as anodic zones, and the AA2050, as the cathodic ones. When the two alloys, AA2050 and AA7050, were exposed separately to 0.005 mol.L-1 NaCl or 3.5 (wt%) NaCl solutions, the AA2050 alloy showed higher electrochemical activity compared to the AA7050 alloy which was due to the higher content of active micrometric precipitates in the AA2050 alloy relatively to the AA7050. However, when the alloys were coupled, the AA2050 was cathodically protected by the AA7050 alloy.

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  • IPEN-DOC 28899

    FONSECA, DANIELA P.M. da; LIMA, NELSON B. de ; PADILHA, ANGELO F.. Oxidation behavior of ultra-high-strength 13Ni15Co10Mo maraging steel. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: During solution annealing and aging of maraging steels an oxide layer is formed, usually composed of hematite and/or magnetite. Exploratory analysis of the oxidized surface of 13Ni-15Co-10Mo (wt.%) maraging steel also indicated the presence of austenite. This maraging steel presents ultra-high yield strength (~3 GPa), however, it shows lower toughness than other maraging steel types and the austenite phase on the surface could obstruct crack initiation and propagation improving toughness. The aim of this study was to investigate the microstructure of the steel surface after oxidation in air by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDX) and X-Ray Diffraction (XRD). Results showed that there are three different regions after oxidation: bulk (constituted of martensite and nanometric precipitates), an intermediate thin layer (composed by austenite, martensite and oxides) and an external layer (constituted of oxides like hematite, magnetite and kamiokite). Chemical microanalysis indicated that the intermediate layer is richer in Ni and Co (austenite stabilizers). Besides identifying the different phases and chemical compositions through the material, from the surface to the bulk, it was possible to understand how austenite is formed during oxidation.

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  • IPEN-DOC 28898

    COUTO, CAMILA P. ; BAERT, KITTY; COSTA, ISOLDA ; PANOSSIAN, ZEHBOUR; DE GRAEVE, IRIS; REVILLA, REYNIER I.; TERRYN, HERMAN; ROSSI, JESUALDO L. . Influence of hot-stamping process on the corrosion initiation and properties of corrosion products at the surface of 22MnB5 steel metallic coated with hot-dip Al-Si. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: 22MnB5 is an ultra-high strength steel combined with hot-stamping process, also known as press hardened steel (PHS). It is a strategic material for the automotive industry because it allows safety improvement, lightweight design and consequently reduction of fuel consumption. In order to prevent surface scale and steel decarburisation during the hot-stamping process, the material is often protected with metallic coatings. Hot-dip Al-Si (Si 10 % in mass fraction) is the most used system for hot-stamping application. This study has the objective to characterize the corrosion initiation and the properties of the corrosion products at the surface of samples before and after hot-stamping process. The samples were submitted to several cycles of accelerated corrosion tests in a salt spray chamber. A systematic characterization of the corroded surface was done by means of Raman spectroscopy and scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM - EDS). The samples were also immersed in a Cl– containing solution, after which the morphology of the corrosion attacks and the corrosion initiation process were studied. The thermo-mechanical process changes the corrosion mechanism as well as the nature of the corrosion products.

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  • IPEN-DOC 28893

    MACHADO, CARULINE de S.C. ; HERNANDEZ, JOSE W.C.; MILAGRE, MARIANA X. ; ARAUJO, JOAO V. de S. ; DONATUS, UYIME; COSTA, ISOLDA . A homemade electrochemical hanging droplet cell to evaluate the corrosion resistance of friction stir weld zones of the AA2198-T8 Al-Cu-Li alloy. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: In this study, the corrosion resistance of the different zones of the AA2198-T8 alloy welded using friction stir welding (FSW) was investigated by immersion and electrochemical tests during exposure to 0.005 mol L-1 NaCl solution. After immersion tests, the welding zones were classified in two groups, according to their severe localized corrosion (SLC) morphology. Zones exposed to higher temperatures during welding presented intergranular attack, whereas those exposed to lower temperatures presented intragranular attack. Electrochemical measurements performed employing a homemade hanging droplet cell revealed potential galvanic coupling between the two groups. The base metal (BM) presented the most anodic potentials. The open circuit potential (OCP) increased from BM towards the stir zone (SZ). The results obtained by the hanging droplet cell were reproducible and coherent with the classification of the zones in the two proposed groups. The homemade electrochemical hanging droplet cell proved a very reliable tool to investigate the electrochemical behavior of the FSWed zones in Al-Cu-Li alloys.

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  • IPEN-DOC 28892

    KLUMPP, RAFAEL E. ; MACHADO, CARULINE de S.C. ; ARAUJO, JOAO V. de S. ; ANTUNES, RENATO A.; MAGNANI, MARINA; COSTA, ISOLDA . A cerium-based nanocoating for corrosion protection of clad on AA 2024-T3 alloy. In: INTERNATIONAL CORROSION CONGRESS, 21st; INTERNATIONAL CORROSION MEETING, 8th, July 20-23, 2021, Online. Anais... Rio de Janeiro, RJ: Associação Brasileira de Corrosão - ABRACO, 2021.

    Abstract: Aluminum alloys are susceptible to localized corrosion resulting in a major risk for aircrafts due to the extensively use of this material in their structures. Therefore, the surface protection of these alloys against corrosion is fundamental. In this work, an eco-friendly surface pretreatment cerium based for corrosion protection alternatively to chromate based ones was developed and applied on the clad of the 2024-T3 aluminum alloy. The corrosion resistance of the modified surface was evaluated by electrochemical impedance spectroscopy, polarization and Scanning Vibrating Electrode Techniques The results obtained were compared to a chromium based conventional treatment and revealed that the coating layer resulting from the tested treatment resulted in a film composed by spherical nodular nanostructures of cerium that improved the corrosion resistance of the alloy studied and it was comparable to the effect of treatment with hexavalent chromium showing it is an promising alternative to replacing treatments based on environmental harmful treatments.

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  • IPEN-DOC 28760

    FREITAS, G.R. ; SOUZA, CARLA D. de . Information management methodology in the control of radiation exposure in computed tomography exams. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... 2021.

    Abstract: In many Brazilian hospitals, computed tomography (CT) is the imaging equipment with greater ionization capability. Systems for monitoring and managing information are not mandatory and the high monetary value for the 'software' acquisition and training results in the non-investigation of the radiation dose received by the patient. Thus, there is a greater likelihood of unnecessary exposures increasing the probability of damage from exposure to ionizing radiation. These can occur because of exams performed out of protocol, poorly referred, repetition in short intervals of time, and operational failures due to malpractice and lack of training of the professionals involved. International organizations such as Image Gently and Latin Safe promote awareness campaigns every year to reduce and control the exposure dose of patients, with monitoring being a pillar for prevention and reducing patient exposure. The present work developed a low-cost methodology, using free tools for storing and evaluating the DICOM-Structured Report (DICOM-SR) and interpreting these data, which can become an economically viable resource for all diagnostic imaging services of the free Brazilian Unified Health System (SUS). A total of 13,734 exams from 9,911 patients were analyzed from September 2019 to August 2021, divided into groups according to their age group. The program was used specially to optimize the head CT protocol. After the first year of training results showed a radiation dose reduction of 11.7%. The new system provides free and simple monitoring of the number of CT scans and the dose received in comparison with the protocols, which, in turn, will result in clinical recommendations for improving procedures and training.

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  • IPEN-DOC 28753

    SCALISE, LEVY ; BURIMOVA, ANASTASIA ; PEREIRA, LUCIANO F. ; FERREIRA, WANDERSON ; SALES, TATIANE ; GONÇALVES, VITOR ; CABRERA-PASCA, GABRIEL; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . DFT-based Calculations of the Magnetic Hyperfine Interactions at Cd Sites in RECd Compounds with the FP-LAPW ELK Code. In: ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, 65th, November 2-6, 2020, Online. Abstract... 2020.

    Abstract: In this work we tested the methodology to map magnetic hyperfine interactions in strongly correlated materials using a free open-source all-electron FP-LAPW code ELK. The RECd (RE = Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) series was chosen as a laboratory system, since an almost complete set of experimental data on the hyperfine parameters at Cd sites in these compounds was acquired previously with an extremely sensitive TDPAC technique [1]. Moreover, these TDPAC results were complemented with WIEN2k DFT calculations that allow a qualitative comparison of the two codes. The ELK calculations were performed with PBE96 GGA-type exchange-correlation functional, the cases of scalar relativistic approximation and fully relativistic relaxation of the states were treated separately. A dense k-mesh and adequate R(MT)K(max) were chosen in both cases to comply with the sensitivity of magnetic hyperfine parameters. We emphasize that the exploited version of ELK accounted for the contact field only. Yet, as it is the only contribution expected for Cd site in RECd, the values of B(hf), albeit generally overestimated, have shown reasonable agreement with the experiment (Fig. 1). Spin-orbit coupling taken into account led to a decrease in deviation from experimental data. An addition of the Hubbard-like term was essential to reach a tolerable result for CeCd. This behavior may be associated with a weaker localization of the 4f electron of Ce. Concerning the potential sources of discrepancy between our ELK results and those previously obtained with WIEN2k, (i) a different way of accounting for relativistic corrections, (ii) the use of GGA (our ELK study) versus LDA (previous WIEN2k study) and other details are discussed.

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  • IPEN-DOC 28752

    MATOS, IZABELA T. ; SALES, TATIANE S. ; CABRERA-PASCA, GABRIEL; BURIMOVA, ANASTASIA ; SAXENA, RAJENDRA N. ; PEREIRA, LUCIANO F. ; OTUBO, LARISSA ; CARBONARI, ARTUR W. . Synthesis and characterization of Fe3O4-HfO2 nanoparticles by magnetization and hyperfine interactions measurements. In: ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, 65th, November 2-6, 2020, Online. Abstract... 2020.

    Abstract: Nanoparticles (NPs) that combine biocompatibility and enhanced physical characteristics for biomedical applications are currently an area of intense scientific research. Hafnium oxide NPs is an innovative approach in the anticancer treatment by radiotherapy due to their low toxicity and enhancement of local dose in the tumor reducing the total radiation dose for the patient [1]. The combination of this amazing property with the excellent magnetic hyperthermia performance of Fe3O4 NPs can produce a promising nanomaterial for cancer therapy. In the present work, we have synthesized NPs samples of Fe3O4 doped with 10%Hf and HfO2 doped with 10% Fe by chemical procedures. The samples had their morphological, structural, and magnetic properties characterized by some results being displayed in Fig. 1. The crystal structure of the samples was characterized by X-ray Diffraction (XRD), whose results present a single phase. Transmission Electron Microscopy (TEM) images show spherical and hexagonal NPs with an average size of 12 nm as displayed in Fig. 2. The magnetic property was investigated by magnetization measurement. The results from the temperature dependence of ZFC-FC magnetization show a large peak in the ZFC curve corresponding to a broad distribution of blocking temperatures as shown in Fig. 1(b). Fortunately, when irradiated with neutrons in a research reactor, the nuclear reaction 180Hf(n,γ)181Hf yields the probe nucleus 181Hf(181Ta) used by the perturbed angular correlations (PAC) technique to measure hyperfine interactions. Both samples show electric quadrupole interaction characteristics of the HfO2 phase indicating that the Fe replaces Hf in HfO2 NPs, but rather than substituting Fe, Hf form HfO2 NPs diluted in Fe3O4 NPs. Moreover, a pure time-dependent magnetic dipole interaction below 300 K was observed for Fe3O4 NPs mixed with 10% of HfO2.

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  • IPEN-DOC 28751

    RODRIGUES, PRISCILA S. ; MATOS, IZABELA T. ; SALES, TATIANE S. ; BURIMOVA, ANASTASIA ; CABRERA-PASCA, GABRIEL; PEREIRA, LUCIANO F. ; SAXENA, RAJENDRA N. ; OTUBO, LARISSA ; CARBONARI, ARTUR W. . Annealing effect on the structural and local magnetic properties of nickel ferrite nanoparticles studied by hyperfine interaction measurements. In: ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, 65th, November 2-6, 2020, Online. Abstract... 2020.

    Abstract: Nickel ferrite in the form of nanoparticles is a technologically important material that can be applied for the production of biosensors, catalysts, drug delivery, and magnetic resonance contrast agents. In this work NiFe O samples comprising spherical nanoparticles of ~6 nm in diameter have been synthesized via a thermal decomposition route. The quality control of the samples was carried out with conventional techniques including X-ray diffraction and transmission electron microscopy. Post-synthesis XRD pattern revealed textured spinel NiFe O . Local magnetic properties were examined with Time Differential Perturbed Angular Correlation (TDPAC) spectroscopy within the 12 - 773K temperature range with In( Cd) probe introduced into the samples at synthesis. Quasi-static magnetic properties were observed (including above room temperature), as expected due to the small time window of TDPAC. The TDPAC results shown in Fig. 1 were analyzed using a model with combined electric quadrupole and magnetic dipole interactions. An expressive dynamic interaction was observed upon heating after synthesis. A theoretical model based on the Brillouin function for different ionic moments was applied to study the evolution of the hyperfine magnetic field with temperature (see Fig. 1-2) and allowed to attribute the magnetic interaction to the probe location at Fe3+ site. Site occupancy and the interplay between magnetic and structural properties are discussed with respect to application perspectives.

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  • IPEN-DOC 28750

    CABRERA-PASCA, G.A.; MAGNO, J.F.; FERREIRA, W.L. ; CAMPOS, A.C. ; BOSCH-SANTOS, B.; SALES, T.S.N. ; PEREIRA, L.F.D. ; BURIMOVA, A. ; SAXENA, R.N. ; FREITAS, R.S.; CARBONARI, A.W. . Local inspection of magnetic properties in GdMnIn by measuring hyperfine interactions. In: ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, 65th, November 2-6, 2020, Online. Abstract... 2020.

    Abstract: GdMn2 is a member of a series of Laves phase containing a rare-earth element and a magnetic 3dtransition metal with very peculiar magnetic properties[1]. Doping with a non-magnetic element such as indium affects these properties[2,3]. GdMnIn is reported to crystalize in the hexagonal MgNi2-type structure presenting a spin-glass behavior with no magnetic order attributed to the triangular spin frustration of magnetic ions[3]. The observed absence of long-range interactions by magnetization measurements along with the almost impossible measurements with neutron diffraction due to the presence of Gd with very high neutron absorption cross section makes the investigation of local exchange interactions in this compound very difficult. In the present work, measurements of hyperfine interactions at In sites using 111In(111Cd) probe nuclei were carried out by perturbed angular correlations (PAC) technique to investigate the local magnetic exchange in GdMnIn compound. Results displayed in Fig. 1 for the behavior of the major component (Vzz) of the electric field gradient (efg) tensor and the distribution of electric quadrupole frequency () show a strong instability of the electronic environment of In sites when temperature decreases indicating a Mn-In disorder. The weak magnetic hyperfine field at In sites also shown in Fig.1 with an anomalous temperature dependence below around 140 K along with the increase in the angle between Bhf and Vzz directions suggest a weak long-range exchange interaction.

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  • IPEN-DOC 23980

    TOMACHUK, C.R. ; ELSNER, C.I.; DI SARLI, A.R.; CULCASI, J.D.; COSTA, I. . Trivalent chromium conversion layer: a way of enhancing the electrogalvanized steel corrosion protection. In: ANNUAL MEETING OF THE INTERNATIONAL SOCIETY OF ELECTROCHEMISTRY, 61st, September 26 - October 1, 2010, Nice, France. Abstract... 2010.

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  • IPEN-DOC 23962

    QUEIROZ, F.M. ; ELSNER, C.I.; DI SARLI, A.R.; TOMACHUK, C.R. ; COSTA, I. . Effect of Cr III passivation on the corrosion resistance of coated electrogalvanized steel. In: INTERNATIONAL SYMPOSIUM ON PASSIVITY OF METALS AND SEMICONDUCTORS, 10th, 10-14 April, 2011, Florianopolis, SC. Abstract... 2011.

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  • IPEN-DOC 22847

    MARTINS, EMERSON A. ; MELO, HERCILIO G. de; COSTA, ISOLDA . Using EIS to assess the protection afforded by phosphate layers to PM produced Nd-Fe-B Magnets. In: ECS MEETING, 216th, October 4-9, 2009, Vienna, Austria. Abstract... 2009.

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  • IPEN-DOC 22806

    NETO, MOISES A.M.; DEUS, ENEIO P. de; COSTA, I. ; CORREA, O.V. ; SOBRAL, ANA V.C.. Influência da corrosão no aço inoxidável duplex em solução de cloreto concentrado. In: CONGRESSO BRASILEIRO DE P&D EM PETRÓLEO E GÁS, 1., 25-28 de novembro, 2001, Natal, RN. Resumo... 2001. p. 263.

    Palavras-Chave: stainless steels; corrosion resistance; chlorides; mechanical properties; metallography

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  • IPEN-DOC 22473

    COSTA, ISOLDA ; MARTINS, EMERSON A. ; MELO, HERCILIO G. de. Corrosion resistance of sintered Nd-Fe-B magnets corrosion and surface treatments for corrosion protection. In: ECS MEETING, 216th, October 4-9, 2009, Vienna, Austria. Abstract... 2009.

    Palavras-Chave: sintering; neodymium; iron; boron; phosphates; surface treatments; corrosion resistance

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  • IPEN-DOC 22472

    FONTES, T.F. ; TERADA, M.; PADILHA, A.F.; MAGNABOSCO, R.; COSTA, I. . Sensibility of mechanical and electrochemical tests in detecting alpha prime phase in duplex stainless steels aged at 475 ºC. In: INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS, 11th, September 20-25, 2009, Rio de Janeiro, RJ. Abstract... 2009.

    Abstract: Alpha prime formation leads to material embrittlement and decreases corrosion and mechanical resistance. In the present study, some tests as microhardness, impact test, electrochemical impedance spectroscopy and cyclic polarization were performed with the duplex stainless steel (DSS) UR 52N+aged at 475 ºC from 0.5 h to 1,032 h in order to evaluate the sensibility of these tests in detecting alpha prime presence. After 0.5 h of aging at 475 ºC it was observed that impact test indirectly revealed the presence of this deleterious phase in the DSS studied, and this test was the most sensible for detecting alpha prime among the other ones used.

    Palavras-Chave: stainless steels; corrosion resistance; microhardness; mechanical properties

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  • IPEN-DOC 22471

    MARQUES, R.A. ; TERADA, M.; SALIBA-SILVA, A.M. ; PADILHA, A.F.; COSTA, I. . The comparison of the corrosion resistance of advanced ferritic stainless steels by Mott-Schottky approach. In: INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS, 11th, September 20-25, 2009, Rio de Janeiro, RJ. Abstract... 2009.

    Abstract: Ferromagnetic stainless steels (SS) have been investigated as potential candidates for dental prosthesis applications in replacement of magnetic attachments made of noble and expensive alloys. In order to be used as biomaterials, their corrosion resistance has to be appropriate. The corrosion resistance of passive materials is related to the characteristics of the passive film formed and this property might be investigated by Mott-Schottky procedure. The capacitance of passive films formed during 2 days of immersion in a Phosphate Buffered Solution (PBS), at room temperature on PM2000, DIN 1.4575 and 17-4 PH ferritic stainless steels (SS) was studied by Mott-Schottky approach. A commercial alloy was also analyzed for comparison reasons. The results showed that films on tested materials behave as both, n-type and p-type semiconductors and the PM2000 presented the highest corrosion resistance among all materials studied.

    Palavras-Chave: ferritic steels; biological materials; stainless steels; teeth; prostheses; corrosion resistance; impedance

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  • IPEN-DOC 28653

    GARCIA, VANESSA S.G. ; TALLARICO, LENITA de F.; ROSA, JORGE M. ; NAKANO, ELIANA; BORRELY, SUELI I. . Avaliação ecotoxicológica de efluente têxtil submetido a radiação ionizante. In: ENCONTRO BRASILEIRO DE MALACOLOGIA, 27.; SIMPÓSIO LATINO AMERICANO DE JOVENS TAXONOMISTAS, 5., 4-8 de outubro, 2021, Online. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Malacologia - SBMa, 2021. p. 162-162.

    Abstract: O setor têxtil demanda elevada quantidade de água para o processo de beneficiamento das fibras, e adicionalmente gera um grande volume de efluente colorido e com diversos contaminantes. Estes são responsáveis por uma parcela importante na degradação dos corpos hídricos em diversas regiões do mundo, causando efeitos adversos aos ecossistemas. Devido a elevada carga tóxica, composição e coloração, geralmente esses efluentes necessitam de tratamentos complementares para melhorar a degradação. Desta forma, tem-se buscado tecnologias mais eficientes para a oxidação destes contaminantes, com ênfase para os processos oxidativos avançados, como a irradiação por feixe de elétrons. O processo com radiação ionizante promove a radiólise da água com formação de radicais hidroxila ou produtos moleculares que atuam na degradação dos compostos orgânicos. O presente estudo dedicou-se a análise da toxicidade aguda de um efluente têxtil (contendo corante reativo Red 239) em dois níveis tróficos do ambiente aquático, o microcrustáceo Daphnia similis e o caramujo Biomphalaria glabrata. A exposição para D. similis foi de 48 horas e o efeito observado foi a imobilidade dos organismos expostos, já para B. glabrata a exposição foi de 24h e observada a letalidade. Os resultados de toxicidade foram expressos pela CE(L)50 (Concentração efetiva/letal mediana). A radiação ionizante por feixe de elétrons foi proposta como tecnologia para tratamento do efluente visando a redução da toxicidade, sendo avaliadas as doses de 2,5 kGy e 5 kGy. As amostras foram irradiadas em Acelerador de Elétrons (Dynamitron®), com energia fixada em 1,4 MeV. A eficiência da irradiação quanto à redução de toxicidade foi obtida a partir dos valores de CE(L)50, transformados para unidade de toxicidade (UT= 100/CE(L)50). Com relação ao efeito agudo para os organismos avaliados, pode-se observar que o efluente bruto foi mais tóxico para o microcrustáceo, com CE50= 9,61% enquanto para B. glabrata foi obtido o valor de CL50=25,09%. As amostras irradiadas, os valores em relação a redução da toxicidade foram melhores se comparados ao efluente bruto: D. similis, CE50%= 12,62 (2,5 kGy); 17,24 (5 kGy), B. glabrata, CL50= 63% (2,5 kGy) e 70,71% (5 kGy). A partir da dose de 2,5 kGy já foi possível observar eficiência em relação a redução da toxicidade para ambos os organismos. Com 5 kGy, a eficiência em relação a redução de efeitos agudos foi superior a 64% em B. glabrata e superior a 44% para D. similis. Os resultados aqui obtidos confirmam que efluentes industriais, como os do setor têxtil, são críticos do ponto de vista de contaminação ambiental, destacando, assim, a necessidade de melhor gerenciamento, tratamento e descarte adequados destes efluentes. Com a tecnologia por feixe de elétrons, foram obtidos dados promissores em termos de tratamento com diminuição significativa da toxicidade.

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  • IPEN-DOC 28652

    GARCIA, VANESSA S.G. ; TOMINAGA, FLAVIO K. ; BOIANI, NATHALIA F. ; SILVA, THALITA T. ; ROSA, JORGE M. ; BORRELY, SUELI I. . Avaliação da toxicidade de surfactantes não iônico e aniônico submetidos a tratamento por feixe de elétrons. In: CONGRESSO BRASILEIRO DE ECOTOXICOLOGIA, 16., 16-19 de agosto, 2021, Online. Resumo expandido... 2021.

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  • IPEN-DOC 20150

    QUEIROZ, F.M. ; SERE, P.R.; ELSNER, C.I.; DI SARLI, A.R.; TOMACHUK, C.R.; COSTA, I. . Study of the corrosion behavior of electrogalvanised steel/Cr(III) and Zr conversion layer/paint system by electrochemical and visual methods. In: EUROPEAN CORROSION CONGRESS, September 8-12, 2014, Pisa, Italy. Abstract... 2014.

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  • IPEN-DOC 17283

    BARDI, MARCELO A.G. ; MUNHOZ, MARA de M.L. ; MACHADO, LUCI D.B. . Effect of transition metal salts on color, gloss and hardness of EB-cured pigmented coatings for polymeric substrates. In: INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... 2011. p. 63-63.

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  • IPEN-DOC 15721

    MARTINS, J.F.T. ; COSTA, F.E. ; SANTOS, R.A. ; MESQUITA, C.H. ; HAMADA, M.M. . A comparative study on the performance of radiation detectors from the HgI2 crystals grown by different techniques. In: INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... 2011. p. 192-192.

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  • IPEN-DOC 15453

    CALVO, WILSON A.P. ; MESQUITA, CARLOS H. de ; SPRENGER, FRANCISCO E. ; COSTA, FABIO E. da ; SALVADOR, PABLO A.V. ; CARVALHO, DIEGO V. de S. ; HAMADA, MARGARIDA M. . Development of the mechanical system on a third-generation industrial computed tomography scanner in Brazil. In: INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... 2011. p. 133-133.

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  • IPEN-DOC 15342

    SOMESSARI, SAMIR L. ; FEHER, ANSELMO ; SPRENGER, FRANCISCO E ; ROSTELATO, MARIA E.C.M. ; MOURA, JOAO A.; COSTA, OSVALDO L. ; CALVO, WILSON A.P. . Automation system for quality control in manufacture of iodine-125 sealed sources used in brachytherapy. In: INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 11-14, 2011, Krakow, Poland. Abstract... 2011. p. 122-122.

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  • IPEN-DOC 15341

    MESQUITA, CARLOS H. de ; VASQUEZ, PABLO A.S ; PEREIRA, JOAO C.S. de M. ; MARTINS, JOAO F.T. ; CALVO, WILSON A.P. ; HAMADA, MARGARIDA M. . Development of a gamma ray computed tomography technique for random packed columns analysis. In: REUNIAO DE TRABALHO SOBRE FISICA NUCLEAR NO BRASIL, 31., 8-12 de setembro, 2008, Marisias, SP. 2008.

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  • IPEN-DOC 28643

    GONCALVES, J.A.C. ; SOMESSARI, E.S.R. ; NAPOLITANO, C.M. ; SOMESSARI, S.L. ; BUENO, C.C. . Transit dose measurements using alanine and diode-based dosimeters. In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st, September 13-17, 2021, Online. Resumo expandido... 2021.

    Palavras-Chave: radiation doses; accuracy; alanines; dosemeters

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  • IPEN-DOC 28642

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Synthesis of thulium-yttria nanoparticles with EPR response. In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st, September 13-17, 2021, Online. Resumo expandido... 2021.

    Abstract: Introduction: High dose dosimetry demands a continuous effort towards the development of new materials with the aim to guarantee assurance of activities in which ionizing radiation is used. The present work reports a hydrothermal synthesis based on a relative low temperature and pressure to form thulium-yttria nanoparticles with electron paramagnetic resonance response. Material and method: Thulium-yttria nanoparticles (Tm:Y2O3) prepared with 0.1at.%Tm (atomic percentage, at.%) were synthesized by an eco-friendly hydrothermal process as reported in previous study[1]. The nanoparticles were characterized by Photon Correlation Spectroscopy (PCS), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Electron Paramagnetic Resonance (EPR). Results: According to results, the hydrothermal method provided thulium-yttria nanoparticles with cubic C-type structure, mean particle size (d50) less than 90nm (Fig.1), and EPR response. The EPR spectra of powders exhibited two resonance peaks p1 and p2 recorded at 350 and 160mT, respectively (Fig.2). Conclusions: The enhancement of the EPR response of yttria by the use of thulium as a dopant provide meaningful parameters to advance in the formation of new rare earth based materials for radiation dosimetry.

    Palavras-Chave: hydrothermal synthesis; temperature range 0065-0273 k; pressure dependence; thulium; yttrium; nanoparticles

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  • IPEN-DOC 28641

    ALMEIDA, S.B. ; CUNHA, A.P.V.; SAMPAIO, C.C.; MENEGUSSI, G.; CAMPOS, L.L. . Small fields dosimetry employing thermoluminescent dosimeters in the clinical aplication of photon beams. In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st, September 13-17, 2021, Online. Resumo expandido... 2021.

    Abstract: Introduction: In radiotherapy, the new techniques have some difficulties such as: beam dosimetry, geo- metric characterization and the use of small radiation fields(1). In some cases, the fields sizes are reduced due to the very small lesions, the simulations of the treat- ment in the planning have a very important role, there- fore, they must be provided with data referring to these small fields. Dosimetry becomes quite complex, as the precision becomes quite contestable, especially when small fields are being used in low density regions(2). Due to the absence of lateral electronic balance, de- termining the dose in the target volume in small field cases is quite difficult. Another problem for this type of dosimetry is the sharp dose gradient at the edges of the field. However, this fact requires that the choice of the radiation detector must be of a relevant size in the dosimetry of small fields, taking into account some parameters such as: high spatial resolution, density equivalent to water, linearity, reproducibility, regard- less of energy and rate of dose(3). Material and method: For this analysis LiF:Mg;Ti (3,15 mm in diameter, 0,9 mm in thickness) and μLiF:Mg;Ti (1 mm x 1 mm) dosimeters produced by Harshaw were used. The irradiation system was the Varian Clinac 6 EX with photon energies of 6MV, with the collimator Multi-leaf Brainlab M3 belonging to the Hospital das Clínicas de São Paulo - HC. In addition, for measurements solid water plates (SW) of 30x30x1cm³ dimension were used. The studied field sizes were 9,8x9,8cm2, 5x5cm2, 4x4cm2, 3x3cm2, 2x2cm2, 1x1cm2 and 05x05 cm2. . Results: The dosimeters were selected with TL sensitivity between ±3%. The TL response presented non-significant variation. The dose response curves to photon beams of 6MV presented a linear behavior in the dose range studied (2Gy to 10Gy). Results obtained in simulated irradiations demonstrated the viability of using μLiF:Mg;Ti as dosimeter to dose evaluation of small photon fields with relatively low uncertainties for this type of application. Table 1 presents the result of TL response of the dosimeters for the studied fields. Conclusions: The dosimetry of small fields is very complex and difficult due to the dimensions of the fields, however the LiF:Mg;Ti and μLiF dosimeters demonstrated an excellent viability for this type of application due to their dimensions being minimal and showing uncertainties below 3%.

    Palavras-Chave: radiotherapy; dosimetry; thermoluminescent dosemeters; radiation doses; photon beams

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  • IPEN-DOC 28640

    OLIVEIRA, L.N. ; NASCIMENTO, E.O.; ANTONIO, P.L. ; CALDAS, L.V.E. . Plastic bottle caps as radiation detectors for high gamma radiation doses. In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st, September 13-17, 2021, Online. Resumo expandido... 2021.

    Abstract: Introduction: Plastic detectors represent an important role in radiation dosimetry [1]. They have been used in a variety of applications, such as portal monitors, and for solar, cosmic, UV, thermal and gamma radiations. Dosimetric evaluation is indicated for material characterization seeking to identify possible applications; proper preprocessing techniques are critical features of this process. This work aimed to determine the linearity response of plastic samples exposed to gamma radiation, using the Fourier Transform Infrared (FTIR) measurements technique. Material and method: Plastic bottle caps were used as sample detectors. They were composed of a hollow cylindrical shape with a 14 mm radius, 0.05 mm thickness, 28 mm height and 3.1 g mass, and they were made of polyethylene (F217). These samples were irradiated in triplicates, with absorbed doses of 0.01 kGy, 0.05 kGy, 0.10 kGy, 0.25 kGy, 0.50 kGy, 1.0 kGy, 5.0 kGy and 10.0 kGy using a 60Co Gamma Cell-220 system (dose rate of 1.089 kGy/h at the Radiation Technology Center of IPEN). Afterwards, each sample absorbance spectrum was acquired on a Fourier Transform Infrared (FTIR) Spectrometer (Frontier/Perkin Elmer) from 400 cm-1 to 4000 cm-1, with 1 cm-1 spectral resolution. The preprocessing was performed in the raw data composed by the broadband source interferogram with a +/- 0.04 cm-1 (2σ) precision for each absorbed dose profile. Subsequently, applying the Fast Fourier Transform (FFT), FTIR was generated. Then, the derivates in the frequency (wavenumber) space were calculated seeking to assess high-order effects. The complex FFT coefficients were explicitly obtained for peak regions, which provided localized information regarding the spectrum approximate shape from the FTIR evaluations to obtain linearity estimatives. The resulting FTIR spectra for each peak was to numerical differentiation at the 1st, 2nd and 3 rd orders (D1, D2 and D3, respectively). The derivates obtained were useful in achieving the spectra shapes and the linearity of response. Results: Figure 1 presents the results after the application of the PCR method: Predicted absorbed dose versus absorbed dose, for: I, II and III regions (from spectrum). The results of the PCR method are the maximum values for linearity, 1.000 for all regions. This result demonstrates that the PCR method is more robust than the linear method, and the preprocessing via PCA provides the information pertinent to the evaluated plastic detector. Conclusion: The results on linearity of response show that plastic bottle caps represent potential radiation detectors for high gamma radiation doses.

    Palavras-Chave: plastics; radiation doses; fourier transformation; gamma radiation

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  • IPEN-DOC 28639

    CARIBE, P.R.R.V.; BONIFACIO, D.A.B. ; CORDEIRO, L.P.; SILVA, A.M.M. da. Influence of BPL-based reconstruction algorithm on image quality for quantitative 90Y-PET imaging. In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st, September 13-17, 2021, Online. Resumo expandido... 2021.

    Abstract: Introduction: PET/CT technology and image reconstruction algorithms are constantly being improved. This leads to changes in the resulting images which need to be tested and clinically validated. This study evaluated the performance and clinical use of the Bayesian Penalized-Likelihood (BPL) reconstruction algorithm on the state-of-the-art SiPM-based PET/CT for quantitative 90Y-PET imaging. Method: An image quality (IQ) phantom with an 8:1 hot sphere-to-background ratio was scanned on a GE Discovery MI 3-rings PET/CT system during a single bed scan. 90Y acquisition time was 14h and 20 min (representative for clinical count statistics) for an activity concentration of 218 kBq/ml. Reconstructions were performed using: 3-iterations OSEM algorithm with 16 subsets and Gaussian post-filter FWHM ranging from 4.5 to 10 mm; BPL-based algorithm employing a block sequential regularized expectation maximization (BSREM) with Beta parameter varying from 300 to 3000. Time-of-flight and point-spread function modellings were included in all reconstructions. Contrast recovery (CR), background noise levels (coefficient of variation, COV), contrast-to-noise ratio (CNR) and metabolic tumour volume (MTV) were compared to investigate whether the BSREM reconstruction algorithm leads to an improvement in clinical image quality using 90Y. Results: The results for CR versus background COV of the IQ phantom are shown in Fig. 1. All plots show a similar trend: CRs values were as expected with higher CRs for lower β and post-filter FWHM values. The Contrast- to-noise ratio was significantly better in BSREM reconstructions when compared with OSEM in phantom studies. In terms of CR mapping, a BSREM β of 1000 corresponded to 5-6 mm post-filter for TOF-OSEM. Regarding noise characteristics of the 14h data, BSREM outperformed TOF-OSEM reconstructions in terms of noise levels with a 2-3 times lower background COV and improved SUVmean and MATV values for all spheres sizes. Lowering the counts for 20 min data, BSREM noise reduction can be controlled by increasing the β- parameter, but caution should be taken to avoid losing CR information. An optimal range of 1500-3000 β values, can provide a compromise between noise and CR at clinical count statistics. Conclusions: Based on a quantitative phantom study, the BPL-based reconstruction algorithm improves image quality and allows better noise characteristics for 90Y acquisitions when compared to OSEM reconstructions. BSREM reconstructions substantially improved contrast-to-noise ratio and MATVvalues for longer 90Y measurements with better count statistics. For clinically relevant count statistics, BSREM with β values lower than 500 had a limited impact on noise levels of 90Y-PET. The potential improvements of BPL applied to dosimetry calculations are currently being investigated to determine if BSREM can be used to avoids accuracy degradation in the absorbed dose distribution aiming at patient comfort.

    Palavras-Chave: images; positron computed tomography; yttrium 90; algorithms

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  • IPEN-DOC 28638

    CAMARGO, F. ; PASCOALINO, K. ; GONCALVES, J.A.C. ; BUENO, C.C. . Evaluation of a diffused oxygenated float zone (DOFZ) diode response as a high-dose dosimeter. In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st, September 13-17, 2021, Online. Resumo expandido... 2021.

    Palavras-Chave: dosemeters; radiation doses; radiation effects; decay

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  • IPEN-DOC 28637

    OLIVEIRA, L.N. ; NASCIMENTO, E.O.; ANTONIO, P.L. ; CALDAS, L.V.E. . Ethylene-vinyl acetate detector exposed to gamma radiation and evaluated via principal component regression. In: LATIN-AMERICAN CONGRESS ON SOLID STATE DOSIMETRY AND RADIATION MEASUREMENTS, 1st, September 13-17, 2021, Online. Resumo expandido... 2021.

    Abstract: Introduction: Applications of ethylene-vinyl acetate (EVA) have been reported in radiation physics research, such as in electron beam irradiations, UV measurements and microwave irradiations. Gamma radiation is well known and presents several applications for radiation dosimetry [1]. The evaluation of EVA and other dosimeters can be undertaken by the Fourier Transform Infrared (FTIR) spectrophotometry technique. The goal of this work was to investigate the effect of gamma radiation in green, white and black EVA dosimeter samples for their sensitivity and linearity response, using the PCR method, and evaluated with the FTIR spectrophotometry technique. Material and method: The EVA samples had dimensions of 0.5 x 0.5 x 0.1 cm3, in colors green, white and black. These samples were irradiated in triplicates, with absorbed doses of 0.01 kGy, 0.05 kGy, 0.10 kGy, 0.25 kGy, 0.50 kGy, 1.0 kGy, 5.0 kGy and 10.0 kGy using a 60Co Gamma Cell-220 system (dose rate of 1.089 kGy/h of the Radiation Technology Center of IPEN); afterwards, the absorbance spectrum of each sample was acquired on a Fourier Transform Infrared (FTIR) spectrometer (Frontier/Perkin Elmer) from 400 cm-1 to 4000 cm-1, with 1 cm-1 spectral resolution. The linearity of response was evaluated using the Pearson correlation coefficient (R2). The sensitivity was set as the linear coefficient from a simple linear regression that was fitted using the Ordinary Least Squares Method between the absorbed doses and absorbance values for each wavenumber in the spectra for all colors of EVA samples. The PCR method combines all spectra from absorbance measurements into a single matrix, called here as Xnm, where n is the absorbed doses that varied discreetly from n = 1 up to 8, matching the absorbed doses of 0.01 kGy, 0.05 kGy, 0.10 kGy, 0.25 kGy, 0.50 kGy, 1.0 kGy, 5.0 kGy and 10.0 kGy, m is the spectral resolution index, from m = 1 up to 3600, equivalent to the range from 400 cm-1 to 4000 cm-1. Results: Predicted absorbed dose versus absorbed dose data are shown in Figure 1, for the PCR method, for EVA samples of all colors. The R2 obtained was 1.000 for the PCR method. It can be inferred that these methods are a good alternative, in the applications that require assessing linearity response in dosimetry, since the measurements from each kind of sample may be transformed in linear results. Consequently, these methods can be associated with other characteristics from radiation dosimetry as: reproducibility, fading, spatial resolution and others. Conclusion: EVA samples can be considered as a promising material for measurements of high doses of gamma radiation.

    Palavras-Chave: vinyl acetate; ethylene; polymerase chain reaction; electron beams

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  • IPEN-DOC 28636

    TRICARICO, JULIANA M. ; SOUZA, CARLA D. de . Avaliação em pacientes da radioterapia oncológica em contato direto e não direto com intervenções durante o curso do tratamento: cartilha educativa para pacientes e profissionais da saúde na área de radioterapia com foco em garantir a completude do tratamento. In: WORKSHOP DO MESTRADO PROFISSIONAL EM TECNOLOGIA DAS RADIAÇÕES EM CIÊNCIAS DA SAÚDE, 3., 8 de dezembro, 2021, São Paulo, SP. Resumo... 2021.

    Abstract: Ao decorrer do tratamento de radioterapia oncológica os pacientes sofrem não somente com as dores físicas mas também com o estigma social que é causado por pressão psicológica de estar acometido com uma doença em que a sociedade chama de “incurável‟. Os profissionais da saúde tem um papel fundamental nesse momento no sentido de ouvir e respeitar as necessidades dos pacientes. O detrimento do estado emocional do paciente pode levar a perda de sessões, atrasos e consequentemente prejudicar o resultado final. Este trabalho tem como objetivo a educação de pacientes e profissionais da saúde, com o objetivo de aumentar a completude dos tratamentos radioterápicos. Isso será atingido por meio de 2 cartilhas contendo informalções que sejam claras e bem discutidas. Informações levadas corretamente através cartilhas e métodos educacionais voltados para a assistencia no campo do paciente oncológico e o seu vinculo de ligação com os profissionais de saúde, não somente educa, mas também gera sensação de segurança e qualidade que contribuem para a completude do tratamento. Embora a maioria das organizações institucionais sejam burocraticas e nem sempre preparam seus profissionais para a capacitação de educação continuada por meio de assitencia com foco na humanização e cuidado centrado no setor da radioterapia, é grande importancia que esse cenario seja olhado atraves de uma nova perspectiva, atraves de mais atenção e capacitação das equipes multi-disciplinares atraves de novas formalizações de planos institucionais que busquem visar e proporcionar para seus pacientes não somente um tratamento, mas também uma contribuição ainda mais valiosa, educando também seus pacientes, para que saibam a finalidade do tratamento, seus beneficios, como lidar com o enfrentaneto da doença e contar com uma rede de apoio disposta a ouvi-los através de cuidado e atenção. As cartilhas serão disponibilizadas gratuitamente em site próprio. Os temas utilizados são: Para Profissionais da Saúde - como o profissional em radioterapia devem se portar dentro setor; de que forma os profissionais em radioterapia devem abordar e auxiliar os pacientes; qual a rotina básica de tratamento no setor de radioterapia; como o profissional da radioterapia devem lidar com uma rotina agitada dentro do setor; quais ajudas os profissionais podem ter dentro ou fora de suas instituições em casos de exaustão; Para o paciente - O que é a radiação; o que radiação faz; o que é a radioterapia; qual a rotina da radioterapia para os pacientes; o que os pacientes podem esperar desse tratamento; quais ajudas os pacientes podem ter além do tratamento.

    Palavras-Chave: neoplasms; radiotherapy; human factors; personnel; health services; therapy

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  • IPEN-DOC 28635

    MARTINS, TAINA M.T.M. ; SOUZA, CARLA D. de. Perfil epidemiológico de caso de câncer de próstata em centro de referência no estado do Ceará entre o período de 2014 a 2019. In: WORKSHOP DO MESTRADO PROFISSIONAL EM TECNOLOGIA DAS RADIAÇÕES EM CIÊNCIAS DA SAÚDE, 3., 8 de dezembro, 2021, São Paulo, SP. Resumo... 2021.

    Abstract: No Brasil, o câncer de próstata é o segundo tipo de câncer mais comum entre os homens. Estima-se que no ano de 2020 ocorreram 65.840 novos casos da doença. Durante a campanha do Novembro Azul, o Ministério da Saúde e o Instituto Nacional do Câncer (INCA) desempenham um papel de suma importância para quebrar preconceitos e paradigmas entre os homens, fazendo com que haja uma busca por informações sobre prevenção e tratamento da doença. Este trabalho tem como objetivo fazer uma análise do perfil epidemiológico para câncer de próstata entre o período de 2014 a 2019, utilizando dados do Centro Regional Integrado de Oncologia – CRIO, localizado no Estado do Ceará. Para isso, foi feito uma revisão dos prontuários dos pacientes. Correlações foram criadas a partir do perfil clinico, social, regional e econômico; tipos e justificativas dos tratamentos indicados; fatores de risco associados ao câncer; e correlacionar a incidência com a região do acometido. Foi usado software Jamovi para fazer a análise de correlação de Spearman e Qui-quadrado. A idade média dos pacientes encontrada na amostra desta pesquisa foi de 71,3 anos de idade, a mínima foi de 44 anos e a máxima 96 anos. A análise da escolaridade revelou que 21,5 % dos pacientes são analfabetos e outros 63,5 % possuem apenas o ensino fundamental. A Grande Fortaleza é a região que detém o maior número de pacientes, 52,5 % e o estadiamento que acomete a maioria dos pacientes é o estágio IIB, seguido do III e IV. As principais modalidades de tratamento inicial foram a radioterapia externa, quimioterapia e hormonioterapia.

    Palavras-Chave: neoplasms; prostate; epidemiology; human populations; statistical data; patients

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  • IPEN-DOC 28634

    FREITAS, G.R. ; SOUZA, C.D. de . Metodologia de gestão da informação no controle de exposição em exames de tomografia computadorizada. In: WORKSHOP DO MESTRADO PROFISSIONAL EM TECNOLOGIA DAS RADIAÇÕES EM CIÊNCIAS DA SAÚDE, 3., 8 de dezembro, 2021, São Paulo, SP. Resumo... 2021.

    Abstract: Muitos hospitais brasileiros, a tomografia computadorizada (TC) é o equipamento utilizado para diagnóstico por imagem com maior poder de ionização. Sistemas para monitoramento e gerenciamento de informações não são obrigatórios e o alto valor monetário para aquisição de ‘softwares’ e treinamento faz com que a dose recebida pelo paciente não seja investigada na maioria das vezes. Com isso, existe uma maior probabilidade de exposições desnecessárias ou até proporcionar danos decorrente de exposições a radiação ionizante (STRAUSS et al., 2019). Esses danos podem ocorrer por causa de exames realizados fora de protocolo, mal indicados, repetição em intervalos curtos de tempo e falhas operacionais em decorrência imperícia, falta de atualização e treinamento dos profissionais envolvidos. Organizações internacionais como Image Gently e Latin Safe, promovem todo ano campanhas de conscientização para redução e controle da dose de exposição de pacientes submetidos a exames de diagnóstico por imagem que utilizam radiação ionizante, sendo o controle e/ou monitoramento um dos pilares para prevenção e redução da exposição de pacientes a radiação ionizante para fins médicos. O presente trabalho desenvolveu uma metodologia de baixo custo, utilizando ferramentas gratuitas para armazenamento e avaliação dos DICOM-Structured Report (DICOM-SR) e interpretação desses dados, podendo se tornar um recurso economicamente viável para todos os serviços de diagnóstico por imagem do Sistema Único de Saúde (SUS). Foram analisados 13734 exames de 9911 pacientes no período de setembro de 2019 a agosto de 2021, divididos em grupos de acordo com sua faixa etária. O programa foi utilizado especialmente para otimização do protocolo de TC de Crânio, o que proporcionou uma redução de 11,7% no primeiro ano de treinamento. O novo sistema proporciona gratuitamente e de maneira simples o monitoramento da quantidade de tomografias e da dose recebida em comparação com os protocolos que, por sua vez, resultarão em recomendações clínicas de melhora de procedimentos e treinamentos.

    Palavras-Chave: computerized tomography; knowledge management; dosimetry; dose limits

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  • IPEN-DOC 28628

    FREIRE, RENAN P. ; SILVA, FELIPE D. ; VITALE, PHELIPE; TODESCHINI, IRIS; MENEZES, FILIPE ; OLIVEIRA, JOAO E. de ; OLIVEIRA, MONA das N.; SOARES, CARLOS R.J. . SARS-CoV-2 Spike (S) glycoprotein expression, purification and characterization in suspension human embryonic kidney cells 293. In: PROTEIN EXPRESSION IN ANIMAL CELLS CONFERENCE, 15th, September 13-16, 2021, Online. Abstract... 2021.

    Abstract: SARS-CoV-2 is a zoonotic virus RNA positive, which became responsible to be the largest sanitary crisis faced by humanity: Coronavirus disease 2019 (COVID-19). Some symptoms include major sneeze conditions, who could evolve to severe acute respiratory syndrome, and in some cases, to death. Techniques for accurate detection of this virus are essential to promote an accurate diagnosis of infected patients. SARS-CoV-2 has several targets with clinical interest; although, the focuses is on Spike (S), a homotrimer glycoprotein, that interacts with angiotensin converting enzyme receptor (ACE2), developing the infection in host cells. Thus, we recognize that the demand for the glycoprotein S is necessary, requiring large amounts with high purity level. The current work has the main objective the transient expression of SARS-CoV-2 S protein into suspension human embryonic kidney cells 293 (HEK293), purification and characterization, to use it as a template for discovering new molecular markers. SARSCoV- 2 S modified protein cDNA was inserted into pαH plasmid, amplified, and purified. For transient recombinant protein expression, 7.5 x 107 HEK293 cells (Expi293FTM cells) was seeded in 27 mL Expi293™ culture Medium. The transfection was carried out with a cationic lipid ExpiFectamine™ and 30 μg of plasmid, mixed with 3 mL Opti-Mem® culture medium. Cell culture was maintained for seven days in 125 mL vent cap Erlenmeyer, 32 ºC, 8% CO2, under 125 rpm orbital shaker rotation. 10 mL aliquots were collected on four- and seven-day post transfection, stored at -80 ºC. Physical-chemical and biological characterizations were determined by SDS-PAGE, ELISA, and Western Blotting. Purification from 40 mL of conditioned medium was carried out in two steps: Strep-Tag affinity column, followed by a size exclusion Superose® 6 (10/300), 5.0 mg of oligomeric recombinant protein with 95% purity was obtained. We believe that this process can be easily adapted to different volumes, being very useful for obtaining, in a short time, enough pure and immunological active SARS-CoV-2 S for further studies and applications, such as, cryogenic electron microscopy, mass spectroscopy, N-glycan structures, antibody production and immunologic assays development.

    Palavras-Chave: coronaviruses; glycoproteins; kidneys; embryonic cells; diagnostic techniques

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  • IPEN-DOC 28598

    LIMA, MAYELLE M.P. ; NASCIMENTO, PAMELA F. do ; NASCIMENTO, ANA C.G. ; VIEIRA, DANIEL P. . A simple and quick method to generate in vitro tridimensional tumor bodies from a human breast adenocarcinoma (MCF7) using magnetic aggregation technique. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 382-382.

    Abstract: Tumor physiology studies have to rely on efficient and representative models, as animal-based or in vitro tridimensional cell constructs. The work used magnetite (Fe3O4) nanoparticles produced by electron-beam induced chemical reduction to give cells the ability to form aggregates when submitted to a magnetic field, and thus to produce micro tumors in vitro. The work aimed to produce human breast adenocarcinoma mini tumors (BAMT's) in vitro. Paramagnetic iron oxide nanoparticles (PION’s) were synthesized through electron-beam induced Fe3+ reduction and subsequent coprecipitation. Due to its poly-L-lysine coating, PION’s were adsorbed on cell membranes of MCF7 (human breast adenocarcinoma). Cells were seeded in 24-well cell culture plates pre-treated overnight with Pluronic® F-127 to prevent cell adhesion and kept in culture conditions under magnetic fields for at least 6 days. BAMT's were differentially stained with Hoescht 33342 and ethidium bromide and imaged by wide-field fluorescence microscopy. BAMT's appeared as integer and well-defined cellular aggregates, with sparse dead cells stained by ethidium bromide. These structures can be further used for in vitro tumor studies, as BAMT’s are supposed to be more reliable models than monolayer cultures. Treatment of wells with poloxamer caused a mild to moderated cell-repellent effect, similar to those found in commercially available products, only by a fraction of the cost. The experiments succesfully produced mini tumors prone to be used in in vitro studies.

    Palavras-Chave: carcinomas; mammary glands; nanoparticles; iron oxides

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  • IPEN-DOC 28597

    NASCIMENTO, ANA C.G. ; GALISTEO JUNIOR, ANDRES J.; SILVA, GIOVANA D. da ; ROCHA, LEONARDO W.P. de S. ; VIEIRA, DANIEL P. . Effective methodology for maintaining Toxoplasma gondii in vitro using paramagnetic iron nanoparticles to support three-dimensional cell culture. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 377-377.

    Abstract: Toxoplasma gondii is a protozoan parasite that infects approximately one billion people worldwide. Upon infection, the host may die due to latent infection or presence with chronic cysts in brain, retina or muscle tissue. Humans can become infected consuming water or foods contaminated with oocysts or eating undercooked meat. Its virulent form is difficult to replicate in vitro, requiring additional steps using experimental animals. The use of nanotechnology can contribute to this in vitro production, through the three-dimensional cultivation of mouse fibroblast cells (NIH/3T3 ATCC® CRL-1658™) and nanoparticles synthesized with radiation. The objective of this work was to demonstrate the three-dimensional culture of fibroblast cells aggregated to nanoparticles for inoculation the T. gondii. This methodology was created to facilitate parasite management and replication. For the production of nanoparticles, the work used concentrations of iron sulfate II heptahydrate (Fe2SO4.7H2O, CAS 7782-63-0) and glycine (NH2CH2COOH, CAS 56-40-6) diluted in ultrapure water free of O2 at pH 12. This solution was irradiated by electron beam of the IPEN / CNEN-SP Radiation Technology Center in doses of at least 15 and at most 30kGy. Paramagnetic iron oxide nanoparticles (PION’s) were then adsorbed on cell membranes, and cells were kept together by a magnetic field. Structured spheroids (4 day of culture) were infected with 106 parasites (RH strain) and the infection was evaluated by transmission electron microscopy. Tachyzoites were found inside 3T3 cells, assuring that the spheroid can be a suitable culture substrate to T. gondii in vitro propagation. A three-dimensional methodology for in vitro cultivation of the parasite is perhaps the key for applications in the study of toxoplasmosis, as it has a fast, cheap, efficient production (yield and reduction of contamination).

    Palavras-Chave: protozoa; nanoparticles; fibroblasts; cell proliferation; in vitro

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  • IPEN-DOC 28596

    SEPULVEDA, ANDERSON F.; FRANCO, MARGARETH ; YOKAICHIYA, FABIANO; ARAUJO, DANIELE de. POLYana: a new software for rheological study of polymeric colloidal materials. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 374-374.

    Abstract: POLYAna is a new executable software developed by SISLIBIO group for rheological analysis of hydrogel and organogel systems and other colloidal materials (nanoparticles and micelles). The software development aims to facilitate the analysis of rheology data associated to both temperature- and frequency-dependent analysis, viscosity and curve flow profiles. The software development aims to facilitate the analysis of rheology data associated to both temperature- and frequency-dependent analysis, viscosity and curve flow profiles. From raw data, several models are applied like power-law model for frequency response and curve flow, Boltzmann law to calculate gelation temperature and viscosity response under temperature, Maxwell model to study interchain relationships in addition to other models such as Bingham model, Cross model, and Herschel-Bulkley are also available. POLYana outputs calculates rheological parameters like consistency, adhesion, hysteresis, flow index, G’/G’’ ratio. To validate results obtained from POLYana, same data were analyzed by applying other programs and same mathematical models. In this sense, rheological analysis of Poloxamer 407 in water solution (15 %) were performed: from temperature-dependent G’ and G’’ analysis were obtained gelation temperature of 45.46 ± 0.02 °C, η_0 = 0.08 ± 0.03 mPa*s, η_max = (32.44 ± 0.17) mPa*s and dη/dT = (1.27 ± 0.02) mPa*s/°C by fitting Boltzmann law (R2 = 0.998), which are similar to results obtained by others softwares and found in literature. From temperature-dependent G’ and G’’ analysis, it gets adhesion value of (1647.15 ± 18.01) mPa*sn calculated from power-law model (R2 = 0.869), also similar to PRISM results. Also, other Poloxamer concentrations and hydrogels types have been evaluated, showing close numbers to that previously reported. In order to stablish structural relationships, one of POLYana tools is also to analyze small-angle neutron scattering (SANS) and develop Monte Carlo simulation for SANS and rheological analysis, simultaneously.

    Palavras-Chave: programming; data analysis; rheology; micellar systems; colloids

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  • IPEN-DOC 28595

    SILVA, CAMILA R. ; PINTO, MAYARA S. ; RIBEIRO, MARTHA S. . Photodynamic therapy associated with ionizing radiation in the treatment of triple-negative breast cancer cells. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 258-258.

    Abstract: Breast cancer is the most common cancer for women worldwide. According to the World Health Organization, it is considered the 5 th leading cause of death from cancer. Triple-negative breast cancer (TNBC) is a subtype of this disease that represents around 20% of all invasive breast cancer, whose main characteristics are resistance to conventional treatments, such as exposure to ionizing radiation (IR). On the order hand, the photodynamic therapy (PDT) using porphyrins and their derivatives has been described in the literature as a potential therapy against cancer. Thus, our goal in this work was to associate PDT and IR in the treatment of TNBC. MDA-MB-231 cells at a concentration of 2x104 cells were submitted to PDT using TMPyP porphyrin (30 μM) and a red light (660 ±11 nm) with fluences of the 23 and 57.5 J/cm 2 (57.3 mW/cm 2). Immediately post-PDT, cells were divided into groups: non-treated (control), only IR and PDT associated with IR (PDT57+IR and PDT23+IR) and then, exposed to IR with a dose of 2.5 Gy. Past 24-h of the PDT-session, the cell viability, clonogenicity and total glutathione were verified. Cells exposed to IR not presented statistically significance difference compared to the control group. However, treated groups showed around 38% lower cell viability in relation to the control and IR groups. For the clonogenic assay a reduction of the approximately 65% was observed between IR and treated groups. Regarding to the total glutathione, all groups showed an increase when compared to control group. Nonetheless, no were identified differences between IR and treated groups. Taken together, our results indicate that PDT associate with IR may be an ally in TNBC treatment.

    Palavras-Chave: neoplasms; mammary glands; therapy; radiotherapy; combined therapy

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  • IPEN-DOC 28594

    PINTO, MAYARA S. ; SILVA, CAMILA R. ; SALVEGO, CAMILA de A. ; RIBEIRO, MARTHA S. . Red LED irradiation impacts the cytotoxic response of murine breast cancer cells to ionizing radiation. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 256-256.

    Abstract: Breast cancer is a disease of worldwide importance since it is considered the 5th leading cause of cancer deaths. Triple-negative breast cancer (TNBC) is a molecular subtype that presents resistance to conventional radiotherapy, demanding high doses of ionizing radiation (IR) for a prolonged period of treatment. On the other hand, low-level light irradiation (LLLI) has been studied to sensitize cells before IR exposure. However, the literature is poor regarding the association of both techniques in TNBC cells. Thus, we aimed to assess the effect of LLLI before IR exposure on two TNBC cell lineages. MDA-MB-231 (human TNBC) and 4T1 (murine TNBC) were cultivated, seeded at a density of 2.5 x 105 cells/cm², and maintained in an incubator (37ºC, 5% of CO2) overnight. LLLI was performed with a red LED (λ= 660 ± 11 nm, 38.2 mW/cm²) delivering energies of 1.2 J and 6.0 J. One-h after LLLI, the cells were submitted to both 2.5 and 5.0 Gy doses from a 60CO source. After 24-h, mitochondrial activity (MA) was quantified by MTT assay with n= 9/group. Our data showed that 4T1 cells exposed to LLLI at 1.2 J exhibited higher MA than cells exposed to IR2.5. In contrast, cells exposed to 6 J of LLLI showed lower MA than IR5. Concerning MDA-MB231 cells, no statistically significant differences were noticed among groups regardless of IR and LLLI doses. These findings indicate that LLLI before IR could sensitize only murine breast cancer. Besides, an appropriate combination of IR and LLLI doses seems to play a role to kill TNBC cells.

    Palavras-Chave: radiotherapy; radiobiology; photochemistry; toxicity

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  • IPEN-DOC 28593

    SOUZA, MARESSA D.F. de ; ITRI, ROSANGELA; RIBEIRO, MARTHA S. . Reconstitution of Leishmania plasma membrane to understand the photodynamic effect. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 255-255.

    Abstract: Leishmaniasis is an important neglected disease. Photodynamic therapy (PDT) has been used to fight cutaneous leishmaniasis showing good results. However, PDT mechanisms in Leishmania parasites are not yet completely clarified. In this work, our objective was to develop a protocol to produce giant plasma membrane vesicles (GPMVs) from Leishmania amazonensis promastigotes to understand the mechanisms of action of methylene blue (MB)- mediated PDT on the cell membrane of parasites. For membrane extraction, several techniques were tested. The osmotic shock was the technique that presented the best yield and effectiveness. Phosphate and protein measurements were performed to confirm membrane extraction. For the growth of GPMVs, the best technique was electroforming using different frequencies and voltages in 4 cycles. Reconstituted GPMVs were observed by phasecontrast light microscopy. Subsequently, PDT was applied to GPMVs dispersed in an aqueous solution containing 50 μM MB and we verified the changes in permeability before and after exposure to light. The same process was applied to giant unilamellar vesicles (GUVs) with lipid compositions similar to the parasite membrane. The electroforming technique with the protocol developed in this work made it possible to obtain GPMVs from a promastigote membrane isolate of L. amazonensis. The membrane isolation technique was effective to extract the parasite's membrane while preserving lipids and proteins. In GUVs we observe an increase in the area during PDT in different compositions and loss of contrast. The GPMVs showed a loss of contrast as well as the GUVs but did not show an increase in area. This factor could be explained by the high degree of complexity of the membrane, which contains membrane proteins in addition to containing lipids.

    Palavras-Chave: therapy; photodynamic therapy; protozoa; parasitic diseases; cell membranes

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  • IPEN-DOC 28592

    SOUZA, TIAGO H. dos S.; ANDRADE, CAMILA; CABRAL, FERNANDA ; SARMENTO-NETO, JOSE; REBOUCAS, JULIO; SANTOS, BEATE; RIBEIRO, MARTHA ; FIGUEIREDO, REGINA; FONTES, ADRIANA. Effects of photodynamic inactivation mediated by Zn(II) porphyrin on promastigote and amastigote forms of Leishmania amazonensis. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 250-250.

    Abstract: Photodynamic inactivation (PDI) has been attracting attention as an innovative technology to treat topical diseases, such as cutaneous leishmaniasis (CL) and infections caused by multidrug-resistant microorganisms. Zn(II) mesotetrakis( N-n-hexylpyridinium-2-yl)porphyrin (ZnTnHex-2-PyP4+) is a lipophilic water-soluble Zn(II) porphyrin with improved photophysical properties, high chemical stability, and cationic/amphiphilic character that can enhance its interaction with cells. Thus, this study aimed to investigate the PDI effects mediated by ZnTnHex-2-PyP4+ on Leishmania amazonensis. Confocal fluorescence microscopy was explored to study the interaction of ZnTnHex-2- PyP4+ with promastigotes. The PDI action was analyzed by cell membrane integrity, mitochondrial membrane potential (ΔΨm), and cell morphology. Promastigotes were incubated with ZnTnHex-2-PyP4+ for 5 min at 0.62 and 1.25 μM and irradiated by a LED (410 nm) for 1 or 3 min (2.3 and 3.4 J/cm2, respectively). PDI on amastigotes and the cytotoxicity on macrophages were also analyzed (3.4 J/cm2). Fluorescence microscopy revealed that parasites efficiently uptake ZnTnHex-2-PyP4+ and displayed a punctate labeling pattern along with the cytoplasm. An intense ΔΨm depolarization was also observed, which in association with microscopy results, suggests that ZnTnHex-2- PyP4+ may accumulate in the mitochondrion, or other well-defined structures close to it. Moreover, ZnTnHex-2-PyP4+ at concentration as low as 0.62 μM led to the immediate inactivation of >95% of promastigotes, regardless of the light dose used. Loss of the fusiform shape and plasma membrane wrinkling were also observed. After a single treatment session in amastigotes, PDI led to a reduction of 70% in the infection index. No considerable toxicity was observed on mammalian cells. Thus, PDI of Leishmania parasites showed in vitro efficiency at a submicromolar concentration of ZnTnHex-2-PyP4+, with short pre-incubation and irradiation times. The results encourage further studies in CL pre-clinical assays and PDI of other microorganisms.

    Palavras-Chave: inactivation; skin diseases; porphyrins; mitochondria; cell membranes

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  • IPEN-DOC 28591

    CONTATORI, CAROLINA G. de S. ; PINTO, MAYARA S. ; RIBEIRO, MARTHA S. . Melanoma cell migration in response to red and near-infrared low-level light. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 249-249.

    Abstract: Cell migration plays an important role in tissue formation and cancer progression. In vitro scratch assay has been used for many years to study cell migration to mimic the migration of in vivo cells, and, thus, to evaluate cancer growth. Low-level red and near-infrared light (LLL) can increase normal cell migration. However, the impact of LLL on tumor cells remains unclear. In this work, we aimed to evaluate the effects of a single LLL dose on melanoma cell migration. B16F10 (murine melanoma) cells were cultivated in RPMI medium with 10% of fetal bovine serum until they reached 80% confluency. The cell line was seeded in a 6-well plate at a density of 2x10 5 cells/well in triplicate at two different moments. A wound scratch was performed to disrupt the confluent cell monolayer with a 10 μL pipette tip. Immediately after the injury, the cells were submitted to the LLL at two distinct wavelengths (660 and 780 nm) provided by a LED and a laser, respectively, delivering 3 different energies (1.3, 3.6, and 6 J) at an irradiance of 4.2 mW/cm2. The control group was not irradiated. Cells were photographed immediately and at 3, 12, 24, and 36 h after the scratch. The wound closure was measured using ImageJ software. To evaluate the overall migration, we calculated the areas under the curve for each group. Cells exposed to the red laser at 6 J migrated slower than control. In contrast, LLL at 780 nm promoted faster cell migration when irradiated with 3.6 J. These results suggest that low-level LEDs at 660 nm could prevent melanoma progression in higher energies. However, 780 nm should be avoided at middle energies.

    Palavras-Chave: melanomas; modulation; infrared radiation; light sources; cell proliferation; migration; in vitro

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  • IPEN-DOC 28590

    MITSUTAKE, HERY; SOUZA, ALESSANDRO D. de; YOKAICHIYA, FABIANO; FRANCO, MARGARETH K.K.D. ; CLEMENS, DANIEL; KENT, BEN; BREITKREITZ, MARCIA C.; RIBEIRO, LIGIA N. de M.; PAULA, ENEIDA de; BORDALLO, HELOISA N.. Evaluation of structural changes of benzocaine-loaded, optimized nanostructured lipid carriers using SANS and Raman imaging approaches. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 183-183.

    Abstract: Local anesthetics are substances that reversibly block the nerve-impulse conduction, alleviating pain without loss of consciousness. Benzocaine, a poorly soluble local anesthetic, is an ester of para-aminobenzoic acid. Several strategies of formulations can be used to improve bioavailability and decrease adverse effects of benzocaine. In this study nanostructured lipid carriers (NLC) were employed. These lipid-based drug delivery carriers have a lipid core composed of a blend of solid and liquid lipids, and a shelf of non-ionic surfactant. The main aim of this work was to optimize benzocaine-loaded NLC and to investigate structural changes in these nanoparticles, under different temperatures. The ratio of excipients (cetyl palmitate, Capmul® PG-8 NF and Pluronic®F68) and benzocaine in the NLC was optimized using a 2 3 factorial design with respect to the following parameters: particle size, polydispersity index (PDI) and zeta potentials. The interactions between the factors were found relevant to determine particle size and PDI. Using desirability function, the best formulation conditions were found. Structural changes in optimized NLC were observed with Small-Angle Neutron Scattering (SANS) and Raman imaging, in samples at 27, 37 and 40º C. SANS pointed the formation of lamellar structures inside the NLC, which interlamellar distances increase at higher temperature. Raman imaging showed that the incorporation of P68 and benzocaine in-between the lipids increased at higher temperatures, explaining the changes in Q values (SANS). This work shows how different scattering techniques can provide complementary information and be used together to characterize and understand the physical, chemical, and structural changes on the organization of pharmaceutical carriers in drug delivery system.

    Palavras-Chave: drugs; pharmacology; anesthetics; drug delivery; design; raman spectra

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  • IPEN-DOC 28589

    SANTOS, CAROLINA M. dos ; SAMPAIO, SUELEN de B.; SANTANA, FAGNER ; LEITE, RODRIGO C. ; PRATA, BEATRIZ A. ; AFFONSO, REGINA . A new approach for purification of the catalytic site of the Angiotensin Conversion Enzyme, N domain, mediated by the ELP-Inten system. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 143-143.

    Abstract: Angiotensin-converting enzyme I, ACE, is a key part of the renin-angiotensin system whose main function is to regulate blood pressure and balance of salts in the body. ACE1 has two isoforms, somatic, sACE, and testicular, tACE. sACE possesses two domains, N- C-, with catalytic sites which exhibit 60% sequence identity. These domains differ in terms of chloride-ion activation profiles, rates of peptide hydrolysis and sensitivities to various inhibitors. N-domain has specific action in the hydrolyze of Alzheimer’s diseases beta amyloid bodies and angiotensin 1-7, which active the MAS receptor and triggering anti-thrombotic and anti-inflammatory actions. The objective this work was to obtain catalytic site Ala361 to Gli468 of the N-domain region, csACEN, isolation without chromatographic and denaturant chemical process. For that, a new methodology was used in the expression of the csACEN peptide, in which the peptide was linked to the elastin-like polypeptide, ELP, and Intein, and expressed at 37C. The characterization of catalytic site was made by SDS-PAGE and dot blotting. The culture temperature at 37C significantly increased the expression of the ELP/Intein/csACEN fusion protein. This culture was lysed at a low temperature allowing the fusion protein to become soluble. The precipitation of ELP at high concentrations of ammonium sulfate were obtained in 0.57 M and 0.8 M. Intein autocleavage occurs at acidic pH and it is important to pay attention to: pI 6.65 for csACEN and pI 6.87 for ELPcsACEN, which are very low. The best autocleavage efficiency was with MES and TriHCl buffers, pH 6.3 and 6.8, respectively, in which pure csACEn peptide was obtained. The strategy used to obtain the Ala361 to Gli468 catalytic site in soluble and pure form was obtained with success and the protocol for obtaining similar peptides was established.

    Palavras-Chave: angiotensin; enzymes; inflammation; thrombosis; temperature dependence

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  • IPEN-DOC 28588

    TREMARIN, BEATRIZ; YOKAICHIYA, FABIANO; KELLERMANN, GUINTHER; FRANCO, MARGARETH K.K.D. ; STORSBERG, JOACHIM. Improvement of the methodological strategies to product functionalizes antibodies using Small Angle Neutron Scattering (SANS). In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 138-138.

    Abstract: Antibodies are used by jawed vertebrates for defense against invading pathogens. Usage of those versatile tools in a plethora of settings in clinics and biomedical sciences hinges on functionalization strategies that retain native antibody reactivity. To this date, antibody functionalization is performed by trial and error. We aim to reduce costs by providing general principles to allow the full spectrum of antibody functionalization by correlating functionalized antibody reactivity to cognate antigen by small angle neutron scattering, SANS, measurements and mathematical modeling of antibody and antibody-antigen super-complexes, obtained by titration experiments. For this research we have used for as antibody pure goat anti rabbit immunoglobulin, and for the antigen, pure Horseradish Peroxidase Preliminary results show that the systems (antibody and antibody-antigen complexes) do not change in the range of a temperature related to storage temperature (25º C), body temperature (37º C) and 40º C. These results will give us the pair distribution function of these systems and the results will be viewed in light of published precedence to highlight areas where future effort is needed to refine such versatile tools and improve their production. However, between the antibody and the complexes structure, different conformations were observed. The antibody has a globular structure with a radius of gyration around 33 Å, and the complexes display an elongated cylindrical shape with radius of gyration around 63 Å. This study shows how the scattering techniques (SANS) can provide useful information about the conformation of the antibody and antibody-antigen formation and help to shed light in the understanding the physical, chemical, and structural changes on the organization of these important antibody functionalization for the immunological system.

    Palavras-Chave: neutrons; small angle scattering; antigen-antibody reactions; biophysics

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  • IPEN-DOC 28587

    ZEZELL, DENISE M. . Radiation Technology in Health Sciences at IPEN: a multidisciplinary and interdisciplinary Professional Master Degree. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 105-105.

    Abstract: The Professional Master Program in Radiation Technology in Health Sciences (MP-TRCS) of the Nuclear and Energy Research Institute- IPEN/CNEN is a new program, started in August 2019. It is the only graduation program in the country to offer two nuclear reactors for educational purposes, for the development of dissertations, in addition to providing radiopharmaceuticals production in a nuclear reactor, in linear accelerator for radioisotope production, as well light and lasers applications. In addition to the infrastructure, the program has multidisciplinary training advisors working in an interdisciplinary manner who use their vast experience in radiation applied to medicine to guide students in a productive manner with a high degree of excellence. The MP-TRCS aims to fulfil a growing demand at IPEN/CNEN from professionals working in hospitals and clinics, using ionizing and non-ionizing radiation. These students need a more dynamic course directed to the practical professional activities. We have students from the most diverse areas, such as medical doctors, biomedical doctors working in clinical analyses, radiotherapy physicists, physiotherapists, dentists specializing in imaging diagnosis and laser, among others, participating in the front line, who use radiation or assess its impact on their day-to-day routine. The first students have already begin to present their dissertation. The employability has increased among students enrolled in the program. These professionals bring their experience to the program, which together with IPEN's academic structure and advisors, result in skilled students who are finding numerous career opportunities in the job market.

    Palavras-Chave: radiations; training; education; educational tools

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  • IPEN-DOC 28586

    VIEIRA, DANIEL P. . Three-dimensional cellular culture system for testing of biological effects of radiations in tumoral and non-tumoral models. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 89-89.

    Abstract: In vitro cell cultures are a well-known controlled test system used to analyze tumor physiologic responses upon negative stimuli. Updated techniques, us-ing three-dimensional organization of cells in cultures, are being increasingly used to this purpose. Research organizations and industry are striving to pro-duce in vitro tumor surrogates that could be better test systems to antitumor agents as new compounds or to study radiation effects on cancers. The presentation will show some techniques currently used to build and maintain these specific cell cultures, and how experiments are evolving towards the production of tumoroids, or tumoral organoids, which will include various cell types and additive manufacturing.

    Palavras-Chave: cell cultures; three-dimensional calculations; tumor cells; radiations

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  • IPEN-DOC 28585

    DEL MASTRO, NELIDA L. ; GERVASONI, J.L.. Women in the nuclear field promoting Latin American integration. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 84-84.

    Abstract: Nuclear energy is used for the generation of electricity, but also for the production of radioisotopes, desalination of sea water and also for the production of hydrogen. Activities in the nuclear field are in the area of science, technology and innovation that has long belonged to an essentially male domain, in which the contributions of women were neglected or underestimated. The central idea for the creation of Women in Nuclear, WiN Global, was to support and encourage women working in nuclear science and technology and encourage the promotion of understanding and knowledge of the benefits of the peaceful use of nuclear energy by the public. WiN Global currently has predominantly female members coming from 129 different countries, belonging to chapters or individually. Today, WiN Global is integrated by 53 WiN Global chapters. Forty-nine countries have their own chapters and there are also regional and international ones. The history of Latin American integration started during the political independence movement of the countries of the New Continent. Since then, up and downs were overcome in order to keep a regional ambiance of good relationship. In the present study, a new form of integration is presented by the efforts of the women working in the nuclear ambit. This important movement involves Latin American WiN chapters (such as WiN Argentina, WiN Brazil, WiN ARCAL) promoting activities for the integration of our region. In order to quantify, to some extent, the participation of Latin American women, this paper presents a survey crossing data of the number of related publications to help to address an objective analysis of the trend of this integration.

    Palavras-Chave: documentation; information retrieval; information systems; nuclear energy; reactor technology; women

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  • IPEN-DOC 28584

    VALLE, MATHEUS del ; SANTOS, MOISES O. dos . Breast tissue diagnosis using artificial intelligence applied to FTIR spectroscopy images. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 42-42.

    Abstract: The estimative of new breast cancer cases was of 2.1 million of new breast cancer cases in 2018, hence being the most incident type of cancer in women. The improvement of its diagnosis has been the aim of many researchers, including vibrational spectroscopy teams. With the advancement of the artificial intelligence, a field of computer science to enhance intelligence into computer systems, specially of the deep learning, big data acquired from spectroscopy image has entered a new era. Therefore, the proposal of this work was to diagnose breast tissue samples as malignant (cancer) or benign (adenosis) using deep learning techniques. Micro-FTIR spectroscopy images were acquired from BR804b human breast tissue microarray (Biomax, USA), resulting in more than 100 thousand spectra for each group. A k-means approach was established to separate spectra into three clusters: tissue, paraffin and slide. A preprocessing step was applied by the following pipeline: outlier removal; biofingerprint truncation; Savitzky–Golay filter to smooth and to obtain the second derivative; extended multiplicative signal correction to correct spectra and remove the paraffin contribution. The deep learning algorithm was built using two-layers of one-dimensional convolutional neural network (CNN) connected to a two-layers (100 and 50 neurons) feedforward network (FFN). Both networks used dropout layers of 50% and rectified linear unit activations. CNN kernel size was set to 5. The output neuron used a sigmoid activation. Adam optimizer was applied to train the networks, using a binary cross-entropy loss to improve the weights. A 4-fold cross-validation of 20 epochs and batch size of 250 was performed. The networks exhibited an accuracy of (97.8 ± 0.4)% during the training stage, and (96.9 ± 0.8)% during the testing stage, demonstrating a generalized classification. Accuracies of almost 100% indicates this approach as a potential technique for the breast diagnosis.

    Palavras-Chave: fourier transformation; infrared spectrometers; artificial intelligence; mammary glands; neoplasms

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  • IPEN-DOC 28583

    YOSHIMURA, TANIA M. ; SAUTER, ISMAEL P. ; RIBEIRO, MARTHA S. . Low power light triggers opposite effects on stem cells: influence of the wavelength and culture conditions. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 41-41.

    Abstract: Photobiomodulation (PBM) has been gaining importance in a wide range of medical fields in the past few years, particularly in stem cell-based regenerative medicine. Improving in vitro cell proliferation, differentiation and viability are ways where PBM could play a pivotal role optimizing biotechnological and bioengineering applications. Here we investigated whether different wavelengths (blue, green and red) would promote distinct outcomes in human adipose-derived stem cells (hADSCs) cultured in regular and supplemented media for tenocyte differentiation. MATERIALS AND METHODS. Freshly isolated hADSCs were cultured in a specific stem cell medium (MSCGM, Lonza), DMEM or a tenogenic medium (TEN-M: DMEM supplemented with growth factors and ascorbic acid). Cells were irradiated every 48 h (23.28 mW/cm 2, 17 min 10 s delivering 24 J/cm 2 per session) using a LED irradiator (LEDbox, BioLambda). MTT and crystal violet assays were used to evaluate cell metabolic activity and proliferation. Red wavelength (660 nm) significantly increased metabolic activity after five irradiations, but only for cells cultured in TEN-M. Oppositely, blue (450 nm) and green (520 nm) light decreased both cell proliferation and metabolic rate, with more pronounced effects for blue light in TEN-M. Considering these findings, we examined whether irradiating only the media would generate toxic compounds that could impair cell viability. We therefore assessed reactive oxygen species (ROS) production by p-nitrosodimethylaniline/ histidine assay while irradiating the three different media under the same conditions as mentioned above. Immediately after blue and green light exposure, an increment in ROS production was observed for DMEM and TEN-M, that continuously increased until reaching between 4.5 and 7.1 μM one-hour after irradiation – with higher values for TEN-M exposed to blue light. Since no significant ROS formation was observed following red light exposure, we concluded that medium composition was responsible for the different effects on metabolic activity and proliferation observed after irradiation with different wavelengths.

    Palavras-Chave: photosensitivity; stem cells; oxidation

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  • IPEN-DOC 28582

    RIBEIRO, MARTHA S. . Light-based non-thermal therapy: from basis to clinical applications. In: CONGRESS OF THE INTERNATIONAL UNION FOR PURE APPLIED BIOPHYSICS, 20th; ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY, 50th; CONGRESS OF BRAZILIAN BIOPHYSICS SOCIETY, 45th; BRAZILIAN SOCIETY ON NUCLEAR BIOSCIENCES CONGRESS, 13th, October 4-8, 2021, São Paulo, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular (SBBq), 2021. p. 39-39.

    Abstract: Light-based non-thermal therapies are evolving as promising non-invasive and cost-effective medical technologies. These therapeutic platforms mainly encompass photobiomodulation (PBM) and photodynamic therapy (PDT), which use visible or near infrared (NIR) light to induce biological responses without any significant heating effects. For PBM, it is most commonly used red or NIR light to optimize light penetration into biological tissues. The photon absorption by natural chromophores at these spectral regions cause photophysical and photochemical reactions inside cells that trigger several biological effects such as to accelerate wound healing, reduce inflammation and relief pain, depending on light parameters and target tissue. On the other hand, PDT makes use of photoactivated drugs, also called as photosensitizers, which absorb light to induce chemical reactions that kill microbial or cancer cells by oxidative stress. Our group have been investigating the mechanisms and several applications of PBM and antimicrobial PDT (APDT) for almost 20 years. In this lecture I will share our experience in the area to discuss how PBM and APDT could be used to revolutionize health care in the photonics era. An integrated perspective from the basic mechanisms, preclinical and clinical trials for both therapies will be presented, including PBM on cancer management and APDT against drug-resistant pathogens. The lecture will also highlight future perspectives.

    Palavras-Chave: antimicrobial agents; photodynamic therapy; therapy; modulation

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  • IPEN-DOC 28578

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . Some facts about nuclear forces and evidence of their range being longer than people believe. In: INTERNATIONAL CONFERENCE ON CONDENSED MATTER NUCLEAR SCIENCE, 23rd, June 9-11, 2021, Online. Abstract... 2021.

    Abstract: Nuclear forces are believed to have ranges around 2 fermi and beyond that range, only electrostatic force is relevant. Before trying to make theories about the phenomena of nuclear reactions observed in solids, it is important to revise critically the existing experimental literature and nuclear theory to check if current models are coherent and if they could explain the observed phenomena. The first step is to check the current nuclear models, the second is to analyse the neutron cross-section data, the third is to discuss coherence between empirical data and models, the fourth is to identify the order of magnitude of nuclear forces range, the fifth is to revise the full height of Coulomb barrier. It was found one isotope (Gadolinium-157) that can attract a thermal neutron at least at 2781 fermi and repulses neutrons at 179 Fermi. It was also found that the plane projection of volumes where neutrons are directly captured is distinct of the projection of the volume where neutrons are scattered for most isotopes. But Kryptonium, Ruthenium, Xenonium, Iridium, and Mercury elements seem having their scattering volumes covered by the absorption volumes, or not having a scattering volume at all. Ca-44, Ca-48, Ni-64, Se-74, Te-123, Dy-162, Hf-177 and W-186 isotopes seem having a partial screening of their scattering volume by the absorption volume. Resonance capture volumes seem to be independent of direct capture volumes and have interface with scattering volume. Three facts suggest absorption volumes are consequence of nucleons arrangement, assuming an FCC nucleus model. The first is that a single additional neutron may change the order of magnitude of absorption radius (like He-3 to He-4). Second, excited states also change absorption cross-sections, like Na-23 whose first excited state increases absorption cross-section and Cl-37 whose first excited state decreases absorption cross-section. Third, neutron capture resonance depends on existence of an excited state of the compound nucleus (target nucleus plus the neutron) with energy larger than this neutron binding energy. In other words, to have a resonance, the target nucleus needs to have two places available for a neutron, and the energetic distance between them needs to be larger than a minimum (the very neutron binding energy). Compared to Coulomb forces, the nuclear forces attracting neutrons are weak, about 6 orders of magnitude smaller than electrostatic repulsion at mean thermal neutron capture radius.

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  • IPEN-DOC 28577

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . A survey on the evolution of yearly works on Pd-D, Ti-D and Ni-H systems within cold fusion field. In: INTERNATIONAL CONFERENCE ON CONDENSED MATTER NUCLEAR SCIENCE, 23rd, June 9-11, 2021, Online. Abstract... 2021.

    Abstract: More than 30 years have been passed since Stanley and Pons press conference announcing the discovery of “Cold Fusion”. This work aims at presenting a general view of the evolution of experimental works in the various sub-fields, like Pd-D, Ti-D, Ni-H systems. For each subfield, this work presents the yearly number of successful and unsuccessful works published in conferences or journals. For Pd-D systems, since 1989, the number of positive results (finding some nuclear reactions) is superior to negative results but there is a trend of reduction of yearly works. Ti-D systems follow the same tendency. Ni-H systems, on the other hand, present a rising tendency besides having a higher ratio of successful/unsuccessful experiments. Perhaps the smaller cost of materials and easier replication is being decisive for new research groups starting in the field, besides enterprises starting advertisement of products based on the Ni-H system.

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  • IPEN-DOC 28576

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . A hypothesis of kinetics and dynamic control of nuclear reactions in solids. In: INTERNATIONAL CONFERENCE ON CONDENSED MATTER NUCLEAR SCIENCE, 23rd, June 9-11, 2021, Online. Abstract... 2021.

    Abstract: Several authors suggested that background noise could influence nuclear reactions in solids, resulting in neutrons or excess heat. Literature shows that repeatability is improving, but the control over the intensity remains out of reach. This work aims at identifying possible causes for intensity variations and proposing solutions to improve controllability. The first step is to search in literature the characteristics of nuclear reactions in solids: input, output, controlling factors and enabling means. The second step is, from solid experimental facts, draw solid conclusions. The third step is developing some assumptions about the phenomenon. For each controlling factor, verify the feasibility of implementation in a heat exchanger with high surface over volume ratio. Finally, present some alternatives of architectures to improve reactions intensity control. A solid conclusion is hot spots come from aneutronic nuclear chain reactions, meaning each energetic charged particle causes the appearance of more than one new charged particle (effective multiplication factor keff>1). Another conclusion is background neutron radiation starts chain reactions and it causes excess heat intensity variations. An assumption is a local keff>1 causes micro explosions terminating the localized reactions because heat propagates faster than the particle population, resulting in low average keff. Therefore, nanoparticles or working temperatures near melting point reduce local keff allowing slow enhancement of particle population up to a level proportional to the background neutrons. A suggestion is to shield the reactors using moderators with neutron absorbers to avoid undesirable power excursions and add a voltage-controlled neutron source to control the excess heat because of the penetrating nature of neutron radiation. Magnetic or electric fields could also help the enhancement of excess heat.

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  • IPEN-DOC 28568

    GERAMI, ADELEH M.; SCHELL, JULIANA; CARBONARI, ARTUR ; COSTA, MESSIAS S.; COSTA, CLEIDILANE; VIEJO, CARLOS D.G.; LORENZ, KATHARINA; PIRES, JULIO; MONTEIRO, JOAO; JOHNSTON, KARL; CORREIA, JOAO M.. Density functional theory study of Cd impurities in molybdenum trioxide. In: ISOLDE WORKSHOP AND USERS MEETING, December 14-16, 2021, Online. Abstract... 2021. p. 27-28.

    Abstract: Transition metal oxides semiconductors (TMOs) are known for their special optical and electrical properties with wide-ranging applications, including gas sensing, storage devices such as Li-ion batteries, solar cells, and catalysts[1,2]. Among different types of TMOs, there is a class of materials that are distinguished by their unique layered structure and multiple oxidation states, such as MoO3, WO3, and V2O5. The molybdenum trioxide (MoO3) is known for its photo-, thermo- and electrochromism, high catalytic activity[3]. The MoO3 has found in different structural phases including the orthorhombic phase, α-MoO3; monoclinic phase, β-MoO3; metastable phase at high-pressure conditions, β′-MoO3; and hexagonal phase, h-MoO3[4]. Among them, the α-MoO3 is the most stable crystal phase and it has a layered structure consisting of van der Waals bonded sheets of distorted edge-sharing Mo−O6 octahedra in which Mo atoms are bounded by three distinct types of oxygen atoms[5]. In this research, the structural properties and hyperfine parameters of 111mCd(111Cd) impurities in α-MoO3 are investigated by first-principle calculations in the framework of density functional theory (DFT). The Perdew–Burke–Ernzerh of generalized gradient approximation (GGA-PBE), and GGA-PBE plus Hubbard-U corrections for onsite Coulomb interactions are used in the DFT calculations. In the calculations performed, the effect of van der Waals forces between layers is employed using the DFT-D3 method[6]. To interpret the experimental results, different configurations around the Cd atom including the different types of oxygen vacancies are simulated. The comparison of experimental data with calculated hyperfine parameters indicates that the Cd atom is predominantly located in the interstitial lattice site of MoO3, and also the oxygen vacancy is most likely to form on the 2-fold coordinated (O2) atoms. The results of this work demonstrate the benefit of first-principle calculations for solving the outstanding questions arising from the experiment.

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  • IPEN-DOC 28567

    BURIMOVA, ANASTASIA ; LEITE NETO, OSMAR F. ; BOSCH-SANTOS, BRIANNA ; CORREA, EDUARDO L. ; PEREIRA, LUCIANO F.D. ; SALES, TATIANE S.N. ; RIBEIRO JUNIOR, IBERE S. ; COSTA, MESSIAS S.; COSTA, CLEIDILANE; DANG, THANH T.; ZYABKIN, DMITRY; VAN STIPHOUT, KOEN K.F.; GERAMI, ADELEH M.; CORREIA, JOAO M.; SCHELL, JULIANA; CARBONARI, ARTUR W. . Cd impurities in Vanadium oxides: a hyperfine interaction investigation using 111mCd nuclei. In: ISOLDE WORKSHOP AND USERS MEETING, December 14-16, 2021, Online. Abstract... 2021. p. 15-16.

    Abstract: The number of metastable phases, the capriciousness at changing external conditions, and lack of accurate description of local behavior already resulted in severe misinterpretation of experimental outcomes for vanadium oxides[1–3]. The scope of already implemented and potential applications of vanadium oxides is, indeed, impressive, particularly as a battery cathode for energy storage[ 4]. Doping is widely exploited as a means of application-oriented tuning of the material properties. The properties of each particular phase may be tuned by doping to satisfy specific requirements and/or improve the functional performance. In the work here reported, electric quadrupole interaction on 111mCd nuclei implanted in vanadium pentaoxide doped with different concentrations of Cd were measured with time-differential perturbed angular correlations (TDPAC). Pure V2O5 as well as doped with 1%, 5%, and 10% of Cd were measured at different temperatures. To correlate the results with the possible formation of different phases and compounds, samples of VO2, CdV2O6, and Cd2V2O7 were also measured. The intention is to provide a comprehensive description, at an atomic level, of the doping effects on the local crystal structure and the electronic structure around the impurity and the consequences on the properties of the host oxides. Preliminary results show that the probability of formation of cadmium vanadates is low but the temperature and atmosphere of measurements have an important effect on the local scale.

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  • IPEN-DOC 28565

    LINS, C. ; MOREIRA, E.G. ; SOUSA, E.P.. Ecotoxicological quality of Caraguatatuba Bay sediment, São Paulo, Brazil. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 14th, September 26-29, 2021, Online. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry (SETAC), 2021. p. 54-54.

    Abstract: Caraguatatuba Bay (-23.66363, -45.43035), at the northern seashore of São Paulo State, Brazil, is exposed to significant sources of marine pollution: domestic effluents and spills of oil and its derivatives. This is due to its proximity to the São Sebastião Channel, where the submarine emissary outfall takes place and where the largest oil transport terminal in Brazil is located. Due to their hydrodynamic characteristics, pollutants tend to deposit in the sediment, impacting the organisms associated with it. These organisms are of great ecological importance, linked to the basis of the food chain and many species are of nutritional and commercial interest. The region remains an important stronghold of artisanal fishermen and mollusk pickers, which raises concerns about the consumption of these organisms by the local population and tourists. The aim of this study was to evaluate the quality of the bay sediment by means of ecotoxicological tests on sediments collected at six points distributed in the bay, in the 2018 winter and in the 2019 summer. Total sediment acute toxicity tests were performed using the amphipod Leptocheirus plumulosus. Samples that presented different results compared to the control sample were only observed in the winter campaign, in three points: Indaiá and Centro Beaches, according to Dunnett's test (p ≤ 0.05) and Indaiá, Centro and Camaroeiro Beaches, according to the t-test (p ≤ 0.05). Sediment samples of these beaches showed adverse effect to the organisms of the assay, being considered toxic. Sediment samples from Porto Novo, Flexeiras and Palmeiras Beaches in winter and all points in the summer campaign did not cause adverse effects to the organisms and were not considered toxic. The three points which samples were considered toxic are on the beaches located from the center to the northern end of the bay where an inlet is formed. The distribution of points with toxicity follows the pattern of particle deposition and approaches the results of sanitary quality of the region according to CETESB, the São Paulo State Environmental Protection Agency.

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  • IPEN-DOC 28564

    TOMINAGA, F. ; LEO, P.; BORRELY, S.I. . Toxicity assessment of acetylsalicylic acid using Saccharomyces cerevisiae. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 14th, September 26-29, 2021, Online. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry (SETAC), 2021. p. 50-50.

    Abstract: Urban and industrial growth has triggered the release of toxic compounds into the environment, causing negative impacts on the population and ecosystems. Among the pollutants, pharmaceuticals have drawn attention due to potential of impacting the environment at ecological relevant concentrations. Aspirin is widely used in human medicine as an analgesic, antipyretic and in actively preventing platelet aggregation, and it is frequently detected in influent samples at relatively high concentrations. The yeast Saccharomyces cerevisiae consists in simple eukaryotic model, widely used for toxicity assessment. The current study aims to evaluate the toxicity of the anti-inflammatory acetylsalicylic acid (aspirin) using viability and conductometric assays. The viability assays were based on the evaluation of the number of viable cells present in a cell suspension after 1 hour exposure, while the conductometric tests were done by monitoring of changes in the specific conductivity of suspensions of S. cerevisiae due to inhibition of fermentation in toxic conditions after 30 minutes of exposure. The viability tests showed no reduction of viability at the evaluated concentrations (up to 100 mg L-1). The conductometric assays demonstrated low sensibility of the yeast to aspirin with EC5030min of 815 mg L-1. The results also indicated that there was no increase in the sensitivity of conductometric assays even at 6 hours of exposure. Furthermore, the acute toxicity data was compared with data obtained from in silico toxicity models (ECOSAR). Toxicity data collated from the software from different trophic levels showed EC5096h, LC5048h and LC96h of 867, 1774 and 777 mg L-1 for green algae, daphnid and fish, respectively, indicating low toxicity of aspirin.

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  • IPEN-DOC 28563

    FERREIRA, LUCAS A. dos S. ; MUCCILLO, ELIANA N. dos S. . Electrical conductivity and grain growth of 12Ce-TZP. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 45-45.

    Abstract: Ceramic materials based on tetragonal zirconia polycrystals (TZP) with yttrium or cerium oxide have been thoroughly studied for a number of technological applications, due to their outstanding thermomechanical properties. In this work, tetragonal zirconia polycrystals containing 12 mol% cerium oxide (12Ce-TZP) were prepared by solid-state reaction using different sintering methods, to evaluate the influence of the final microstructure on the electrical conductivity. High purity zirconium oxide and cerium oxide starting chemicals were weighted in the stoichiometric proportion and ball-milled for 6 h for homogenization. Cylindrical specimens were prepared by pressing followed by sintering. Sintering experiments were carried out by the conventional and the two-stage methods. The mean grain size of specimens sintered by the conventional method achieved approximately 2.4 mm after sintering at 1450 ºC/5 h, whereas those sintered by the two-stage method exhibit less than 1.5 mm even after 10 h at 1350 ºC, in the second stage of sintering. The electrical conductivity determined by impedance spectroscopy shows the usual Arrhenius behavior for both the bulk (or intragrain) and grain boundary (intergrain) conductivities, with activation energies of ~0.97 (bulk) and 1.25 eV (grain boundary). The grain conductivity of specimens sintered by different methods does not depend on the grain size. In contrast, the grain boundary conductivity is higher for specimens sintered by the two-stage method, possibly due to dissolution of minor impurities located at grain boundaries into the bulk, during the long holding times of the two-stage method.

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  • IPEN-DOC 28562

    SILVA, JOSE T. da ; SOUZA, CARLA D. de ; NOGUEIRA, BEATRIZ R. ; ANGELOCCI, LUCAS V. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Homogeneity evaluation of phosphorus-32 epoxy plaques to be used in the treatment of spinal and intracranial cancer by brachytherapy. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 919-919.

    Abstract: In Brachytherapy, radioactive source is positioned close to the tumor. The most important advantage is that the target region receives most of the dose, protecting the healthy tissues adjacent to the tumor region. In order to use these sources, a high dosimetric uniformity must be achieved, so a homogeneous dose delivery can be delivered to the target. In the present work, the consistency of the epoxy resin plate was evaluated using a methodology developed in the laboratory for the production of radiotherapy sources at IPEN / CNEN - SP. Several tests were carried out to determine the best mold for the source manufacture. It was concluded that polytetrafluoroethylene (PTFE), which is commercially known as teflon, obtained the best result, due to the ease unmold of the source after the resin curing process. The epoxy plaques were produced with resin 2220 and catalyst 3154 (Avipol), at a 2:1 mass ratio. To simulate the radioactive material, hydrochloric acid (HCl) equivalent to 5% of the total mass (resin + catalyst) is added. The epoxy resin cured for 24 h at room temperature. The thickness of the plaques was measured reaching an average value of 0.300 mm ± 0.070. The measurements were made with a micrometer, measuring 10 points of each plaque. The measures of width and length were not performed, as these parameters do not influence the uniformity of the dose. In order for the distribution of phosphorus-32 activity to be stipulated, a Monte Carlo Simulation using the MCNP code was performed. The maximum dose variation along the plaque, considering a totally uniform thickness of 0.300 mm, resulted in <0.5% up to 0.5 cm before the edge. The result of the simulation shows that with a uniformly thick plaque, the dose distribution trend is homogeneous. Based on the results, the epoxy polymer plaques are shown to be viable for use in brachytherapy, and the next step of the work will be the tests with radioactive material.

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  • IPEN-DOC 28561

    TRINDADE, FABIANE J.; DAMASCENO, SERGIO; OTUBO, LARISSA ; SCHMAL, MARTIN; FLORIO, DANIEL Z. de; FONSECA, FABIO C. ; FERLAUTO, ANDRE S.. Lanthanum doped ceria shaped nanostructures for oxidative coupling of methane. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 308-308.

    Abstract: The abundance of natural gas due to the advancements in exploration and extraction technologies has increased the interest in the direct conversion of methane to C2 molecules via oxidative coupling of methane (OCM) reactions [1]. The design of catalysts by tailoring shape and oxygen vacancies has a significant impact on their performance [2]. Within this context, in this work, the fine-tuning of structural defects of ceria rod-like and cube-like shaped nanoparticles were performed via La3+ doping (LaxCe1-xO2-x/2) in molar ratios of x=5-90 mol %. The morphology control was achieved by varying the hydrothermal synthesis temperature from 110 °C to 180 °C. The characterization of LaxCe1-xO2-1/2 catalysts was performed by SEM, HRTEM, XRD, and Raman spectroscopy. The catalytic performance of the new nanomaterials for the OCM reaction was studied at 750 °C with an in-line gas chromatograph. In the LaxCe1-xO2-x/2 nanorods, the fluorite crystalline structure is essentially maintained even for x = 0.6. The Raman spectra analysis indicates that the addition of La3+ leads and increases the formation of different amounts of extrinsic and intrinsic oxygen vacancies. In addition, the catalytic tests for OCM reaction show that the LaxCe1- xO2-1/2 (x=50%) nanorods catalyst have 25% of CH4 conversion and 48% of selectivity for C2 products. The concentration of reactive oxygen species in the LaxCe1-xO2-1/2 (x=50%) nanorods was crucial to improving the conversion rates and selectivity.

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  • IPEN-DOC 28560

    CARVALHO, SABRINA G. de M. ; MUCCILLO, ELIANA N. dos S. ; MUCCILLO, REGINALDO . Ionic conductivity of electric field-assisted sintered gadolinia-doped ceria/alkali salts membranes. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 299-299.

    Abstract: Ceramic-carbonate dual-phase membranes were prepared according to the usual procedure: by vacuum impregnation of molten sodium-lithium carbonates (NLC) into sintered porous ceria-20 mol% gadolinia (20GDC) solid electrolyte cylindrical pellets; and also by flash sintering samples with 75 wt.% (CeO2: 20 mol% Gd2O3) and 25 wt.% NLC. Sintering was accomplished by applying 200 V cm-1 to the membrane positioned in a sample holder of a dilatometer for monitoring thickness shrinkage, limiting the electrical current to 1 A. Electrochemical impedance spectroscopy measurements were performed in the 5 Hz-13 MHz frequency range from 300ºC to 600ºC in composite ceramic membranes, covering the solid-to-molten NLC temperature range. Analysis of the impedance diagrams allowed for the evaluation of the oxide ion and carbon dioxide ion conductivities. The Arrhenius plots showed the transition from oxide ion conduction (due to the solid electrolyte) to carbonate ion conduction (due to the molten NLC). The ionic conductivity values of membranes flash sintered at 420ºC in 2 min were higher than those of conventionally sintered membranes and similar to reported values of membranes sintered at 690ºC for 2 h.

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  • IPEN-DOC 28559

    DIAZ, JULIO C.C.A. ; MUCCILLO, REGINALDO . Impedance spectroscopy analysis of flash sintered zirconia: 8 mol% yttria solid electrolytes with alkali halide addition. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 298-298.

    Abstract: Electrical properties of porous ZrO2:8 mol% Y2O3 ceramics with LiF sintering aid were studied. The specimens were sintered by transient liquid phase formation under the application at 650ºC of 200 V cm-1 AC electric field for various current density, current elapsed time, and lithium fluoride content. Low electric current densities coupled with long application times produced homogeneous specimens. Variations in the electric current density and current elapsed time allowed to obtain sample densification in the 60%-75% range. Impedance spectroscopy measurements were carried out to estimate the relative pore content, evaluating the product of the blocking factor αR (=Rg/(Rg +Rgb), R, g and gb stand for resistance, grain and grain boundary, respectively) to the frequency factor αf (= fgb/fg, f is the characteristic frequency), which is proportional to the blocker volume, i.e., the porosity. A direct correspondence between αR•αf and the apparent porosity, obtained after determining the apparent density by the Archimedes method, was observed.

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  • IPEN-DOC 28558

    PELOSI, ANDRE G.; SANTOS, SABRINA N.C. dos; DIPOLD, JESSICA ; ANDRADE, MARCELO B. de; HERNANDES, ANTONIO C.; ALMEIDA, JULIANA M.P. de; MENDONCA, CLEBER R.. Investigation of the influence of transition metal ions in niobium-borotellurite glasses through vibrational and nonlinear optical spectroscopy. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 176-176.

    Abstract: Tellurite glasses are know as good candidates to photonic devices’ production because they exhibit third-order nonlinear optical susceptibilities larger than conventional silicate and borate glasses. In addition, for glass materials such nonlinearity can be increased by adding transition or heavy metal ions. In this direction, this work analyzed the influence of Ta5+ and Zr2+ on the physical, structures, and nonlinear optical properties of niobium-borotellurite (TBN) glasses. The samples were synthesized by the melt-quench technique using a melting temperature of around 1000 ºC. DSC measurements were performed to obtain the glass transition temperature. The densities were determined by the Archimedes method. To analyze the local structure of the samples FTIR and Raman spectroscopies were used . The spectrum of nonlinear refractive index (n2) for the TBN glass doped with Ta5+ and Zr2+ ions was measured using the tunable femtosecond Z-scan technique [1]. Such results were compared with the BGO model, which involves empirical relations between the linear and nonlinear refractive index. The addition of metal transition ions did not lead to meaningful changes in the glass transition temperatures (Tg). The formation of non-bridging oxygen and BO3 units was observed from the structural analysis. The n2 value determined indicates that the nonlinear optical responses are associated with the glass matrix. The structural changes caused by the addition of Ta5+ and Zr2+ demonstrated a decrease followed by an increase in the value of the molar electronic polarization of the samples, respectively.

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  • IPEN-DOC 28557

    DENALDI, RAFAEL L. ; MUCCILLO, REGINALDO . High temperature percolation of carbonate ions through porous alumina and zirconia-magnesia impregnated with alkali carbonates. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 305-305.

    Abstract: Na2CO3-K2CO3 (56-44 wt.%) eutectic composition was vacuum-impregnated into porous Al2O3 (alumina) and to ZrO2: 3 wt.% MgO (magnesium-partially stabilized zirconia, Mg-PSZ) at the molten eutectic temperature. Porosity was achieved in the two compounds by addition and thermal removal of the eutectic composition before impregnation. The parallel surfaces of disk-shaped impregnated compositions were observed in a scanning electron microscope. The CO3 2- carbonate ion conductivity of the two composite ceramics was measured by electrochemical impedance spectroscopy in the 5 Hz-13 MHz frequency range from 470ºC to 780ºC. The permeation of the carbonate ions via eutectic composition through the ceramic membranes was ascertained by the threshold temperatures of the onset of the carbonate ion percolation: 660ºC and 720ºC for alumina and Mg-PSZ, respectively.

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  • IPEN-DOC 28556

    SOUZA, JULIANA P. de; SERNA, JILDER D.P.; MORAES, LETICIA P.R. de ; SILVA, JULIO C.M.; ALVES, ODIVALDO C.. Structural and magnetic properties of CeO2 nanomaterials as a function of different morphologies: nanocube, nanowire and nanobelt. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 128-128.

    Abstract: The nanomaterials of cerium oxide can be applied in catalysts, fuel cells and spintronics [1]. Additionally, in its crystalline structure, small defects named oxygen gaps appear, caused by its high potential pattern of reduction from Ce IV to Ce III or that it becomes an oxidizing agent and the conferring agent. In this work we investigated the magnetic properties of three ceria morphologies on a nanometric scale: nanocubes, nanowires and nanobelt that were synthesized using the hydrothermal method. As samples prepared from studies by using X-ray diffraction (XRD), transmission electron microscopy (TEM), magnetometry (VSM) and paramagnetic resonance (EPR). XRD measurements show characteristic peaks of ceria fluorite face-centered cubic structure. Measurements of magnetization in function of the field applied at room temperature showing the ferromagnetic character with different values of the coercive field and saturation magnetization, we observe an increase in the coercive field and saturation magnetization in ceria nanocubes that can be explained by an increase in the density of vacancy [2]. The zero field cooled (ZFC) and field cooled (FC) magnetization curves measured on low magnetic fields show a soft maximum around 60 K attributed to oxygen at the sample surface. Applying to the Curie-Weiss equation indicates the presence of antiferromagnetic interactions mainly in nanobelt and nanocubes morphologies. The EPR spectra at room temperature show two paramagnetic symmetry, with axial symmetry with g1 = 1.97 and g2 = 1.94 associated with Ce 3+ and another isotropic around g = 2.03 due to vacancies of isolated oxygen for all samples. The ferromagnetic arrangement characterized by the presence of broad signals at about 3500 G is also observed in nanobelt morphologies.

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  • IPEN-DOC 28555

    ALVES, ANDRESSA A.; QUEIROZ, ÁLVARO A.A. de ; QUEIROZ, ALFREDO A.A.E. de. Fabrication of hyperbranched polyglycerols microcapsules from microfluidics guided by artificial neural networks. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 854-854.

    Abstract: In recent years, the microfluidic approach has received a lot of attention from the scientific community due to the simple and efficient synthesis of highly monodisperse microcapsules used in a variety of applications in biotechnology and medicine such as, for example, materials synthesis, drug encapsulation, among others [1,2]. Thus, in this work, hyperbranched polyglycerol microcapsules (HPGM) were developed using microfluidic technology. Artificial neural network (ANN) feed-forward using multilayer perceptron architecture was trained and applied to model and predict the microfluidic process. The HPGM produced were characterized by scanning electron microscope (SEM), attenuated total reflection-Fourier transform infrared (ATR-FTIR) and thermogravimetric analysis (TGA). The fabricated HPGM showed spherical size and monomodal distribution with an average diameter of 29 μm. The developed ANN proved to be efficient predictor, showing well agreement with the experimental data (R2=0.9983). Based on these results in this research, it was found that the microfluidic device for producing HPGM was successfully developed since it was possible to synthesize microcapsules with targeted properties, monodispersed with high stability and low porosity. In this way, microfluidic technology guided by ANN can be used to synthesize HPGM for biotechnology processes.

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  • IPEN-DOC 28554

    PORFÍRIO, TATIANE C. ; MUCCILLO, ELIANA N. dos S. ; MUCCILLO, REGINALDO . Electric field-assisted synthesis/sintering cerium oxide: 5 wt.% gadolinium oxide. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 321-321.

    Abstract: Gadolinium oxide ceramic powders were mixed to cerium oxide ceramic powders, pressed to pellets, and sintered either at 1450ºC for 4 h or applying 200 V cm-1 electric field at 800ºC, 900ºC and 1000ºC. The structural phases and the microstructure of the sintered pellets were analyzed by X-ray diffraction and scanning electron microscopy, respectively. The formation of substitutional solid solution was followed by monitoring the increase of the electrical conductivity by impedance spectroscopy measurements and the X-ray diffraction patterns. The main results show that Joule heating due to the flow through the pellets of the electric current, which was produced by the application of the electric field, allows for promoting partial solid solution as well as partial sintering the ceria-gadolinia pellets. Moreover, grain growth that occurred in the high temperature sintered pellets was inhibited in the electric field-assisted synthesized/sintered pellets, being an alternative technique for producing cerium oxide-gadolinium oxide solid solutions.

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  • IPEN-DOC 28553

    LANDGRAF, FERNANDO J.G.; MORAIS, WILLY A. de; GUZMAN, JHOAN; MARTORANO, MARCELO; NOBRE, RAFAEL de M.; NEVES, MAURICIO M. das . Effects of laser power and speed on keyhole formation during additive manufacturing by laser-powder bed fusion. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 656-656.

    Abstract: Unique microstructures are generated by the laser powder bed fusion (L-PBF) process of additive manufacturing. The moving molten metal pool created by the laser beam leaves a metallographic evidence, here called melt pool profile. The melt pool profile is easily identified in many alloys owing to the severe segregation at the beginning of the epitaxial cellular solidification, on the border of the remelted zone. The resulting microstructure is associated with the laser scanning strategy used in building the piece. Twenty-four different conditions of laser beam speed and power were adopted for a bed of plasma atomized powder of a Nb-48% Ti alloy. Width and depth of the melt pool profiles in the top layer of all samples were analyzed by optical microscopy. For lower energy densities and faster laser scanning speeds, the shape of the melt pool profile is nearly parabolic. When the speed decreases, within a certain limit dependent on the laser power, the shape changes to a characteristic keyhole-type profile, with a larger depth to width ratio. The keyhole profile is due to the presence of a wide, shallow parabolic pool and a narrow and deep pool formed by a transient evaporation cavity. The experimental results are compared to the available literature.

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  • IPEN-DOC 28552

    FRANCISCO, LEONARDO H.C. ; MOREIRA, RENAN P. ; SALVADOR, FRANCINE F. da S. ; MOTTA, MARCIO P.; FELINTO, MARIA C.F. da C. ; BRITO, HERMI F.. Near-infrared emitting Cr(3+)-doped mixed oxide luminescent materials for optical imaging. In: BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS, August 30 - September 3, 2021, Online. Abstract... São Carlos, SP: Aptor Software, 2021. p. 194-194.

    Abstract: The rapid growth of optical imaging in the latest years proposes novel alternatives to well-established imaging techniques, in a way that current research interest within this field is now focused on the design of efficient photonic materials and optical sensors[1-2]. In this scenario, this work presents the development of Cr3+-doped Zn/Mg/Sn mixed oxides prepared via solid-state and microwave synthesis, exhibiting interesting spectroscopic properties in the red to near-infrared (NIR) range. Prepared compounds were analyzed by PXRD, where the obtained diffraction profiles followed mainly the overlapping Mg2SnO4 and Zn2SnO4 patterns, and crystallite size was estimated to be about 70 nm. SEM/EDS analysis revealed micrometer-sized particles up to 20 μm, but much smaller particles and homogeneous Cr3+ distribution were also observed. Moreover, Synchrotron radiation measurements obtained at the Brazilian Synchrotron Light Laboratory, on the TGM beamline via Vacuum UV Spectroscopy within the 4.5–7.5 eV energy range revealed distinct emission profiles with increasing Zn concentration, affecting the contribution of deep-red and NIR vibronic sidebands at 700 and 720 nm, respectively. Still, maximum absorption energies (about 6.6 eV) remained constant for all the analyzed compounds, whereas the broad-band NIR emission of Cr3+ ion centered around 770 nm assigned to the [4T2(t2e)→4A2] transition is predominant. Persistent luminescence decay curves under near-band gap excitation were also probed. Thus, in this work, we demonstrated an effective way to assemble NIR emitting luminescent materials with potential applications in optical imaging and photonics, where similar and expensive Cr3+-doped gallates are already widely explored.

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  • IPEN-DOC 18922

    GOTTARDI, MARIELLA da S. ; KAWAMOTO, DIONE; ZAMATARO, CLAUDIA B. ; ANA, PATRICIA A. da ; MAYER, MARCIA P.A.; ZEZELL, DENISE M. . In vivo study of diode laser 940 nm operating in high intensity mode in the periimplantitis disease. In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser in Dentistry, 2018. p. 62-62.

    Abstract: The evolution of periimplantitis has been associated with several risk factors. The standard treatment consists on subgingival scaling and blasting with sodium bicarbonate. This 6 months longitudinal clinical study evaluated and compared two treatment methods: conventional as described and complemented by irradiation with high intensity diode laser (940 nm, Biolase) aiming to establish a more efficient periimplantitis management. After approval by the Human Research Ethics Committee, 20 patients of both sexes, with implants in function for at least 12 months and with diagnosis of periimplantitis were selected and randomly distributed in two experimental groups. Ten of them were conventionally treated as control group, and the remaining ten were in the laser treated group (1W, 4.24kJ/ cm2 energy density, pulsed mode, 30s, twice). There were six sites for treatment standardization: vestibular region (mesial, central and distal thirds) and buccal region (mesial, central and distal thirds). Results has shown that overall clinical evaluation has no significant difference between groups control and treatment. less bleeding and suppuration, as shallower periodontal pocket indicated a decreasing tendency on laser treated group. Quantitation of total bacteria and Porphyromona gingivalis by real-time PCR shown that laser synergy is a complementary therapy that could act as an additional option to the conventional treatment in difficult response cases.

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  • IPEN-DOC 18813

    MORAES, MARCIA C.D. ; PEREIRA, DAISA L. ; ZAMATARO, CLAUDIA B. ; ZEZELL, DENISE M. ; FREITAS, ANDERSON Z. . Effect of Nd:YAG laser on caries prevention of dental enamel by optical attenuation coefficient with optical coherence tomography (OCT). In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser in Dentistry, 2018. p. 48-48.

    Abstract: Caries is a multifactorial disease, caused by the continuing loss of hydroxyapatite crystals. The association of topical acidulated phosphate fluoride application (APF) and high intensity lasers has the potencial to increase the resistance to demineralization of dental tissues. The Nd:YAG laser, specially associated to a photoabsorber over the dental surface, may induce thermal changes in order to increase the resistance to demineralization. Optical Coherence Tomography (OCT) is a non-ionizing radiation imaging technique that can be performed in real time in vivo and can detect early changes in the optical properties of t issues. This study aimed to characterize the effectiveness of the association of Nd:YAG la ser and APF gel in the prevention of caries lesions in human dental enamel in vitro, due to structural changes in function of the pH cycling, the treatments performed as well as to evaluate the potential of OCT to diagnose early demineralization. 160 human enamel samples were divided in four groups and submitted to pH cycling during 20 days, after the following treatments: G1- untreated; G2- treated with APF gel (1.23% F-, 4min); G3- irradiated with Nd:YAG (1064nm, 84.9J/ cm2, 10Hz) followed by APF application and G4- APF application before Nd:YAG laser irradiation (same conditions of G3). OCT (930 nm) analysis were performed before and after the treatments, 5th, 10th, 15th and 20th day of pH cycling. The optical attenuation coefficient decreased significantly (p<0.05) as demineralization increased over time and better results were achieved in group G4. OCT technique can diagnose early demineralization in enamel.

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  • IPEN-DOC 18688

    PEREIRA, DAISA L. ; MORAES, MARCIA C.D. ; ZAMATARO, CLAUDIA B. ; ZEZELL, DENISE M. . Longevity of diode laser irradiation in dentine: an in vitro study. In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser in Dentistry, 2018. p. 47-47.

    Abstract: The efficacy of pulsed infrared lasers on clinical dentin wear sensitivity is well stablished in the Literature. This work aims to evaluate the effect of diode laser combined with fluoride products regarding the longevity of the sensibility treatment under the effect of the domestic use products. After Ethics Committee approval, 75 slabs of bovine root dentin measuring 8 mm2, were randomized into 5 groups (n=1 5): G1- untreated; G2- treated with acidulated phosphate fluoride (APF-gel, [F-J=1.23 %, pH=3.3 to 3.9); G3- irradiated with diode laser (980 nm, 2.5W, 5ms, 25Hz) using a cool paste as photoabsorber; G4- irradiated with diode laser (same conditions of G3) using a coal paste as photoabsorber + application of APF-gel and G5- application of APF-gel+ diode laser irradiation (same conditions of G3). All samples were submitted to an erosive and abrasive demineralization (Sprite Zero, pH=2.8, 90s, 4x/day), and remineralization (artificial saliva, pH=7.4) cycling for 10 days. Twice a day, slabs were brushed for 15s using a whitening dentifrice (Sensodyne True White, GSK, EUA). Slabs were evaluated by Optical Coherence Tomography (OCT) at the initial and 7th day of cycling. OCT measurements found a significant increase on dentin wear depth and area of lesions with the increase of cycling days. G1 and G2 hod significant higher mineral loss compared to the other groups. G3, G4 and GS showed no significant differences between them. Results suggested that the sensibility of the treatment with the diode laser has longevity despite the high abrasivity of dentifrice used in maintenance.

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  • IPEN-DOC 18613

    ZAMATARO, CLAUDIA B. ; PEREIRA, DAISA de L. ; LIMA, CASSIO A. ; SCAPIN, MARCOS A. ; ZEZELL, DENISE M. . Gamma sterilized human dental enamel submitted to Er,Cr: YSGG laser irradiation associated to fluoride for in situ model. In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser in Dentistry, 2018. p. 89-89.

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  • IPEN-DOC 18533

    BEZERRA, SAVIO J.C.; TREVISAN, LETICIA R.; VIANA, ITALLO E.L.; LOPES, RAQUEL M.; PEREIRA, DAISA de L. ; SAKAE, LETICIA O.; ARANHA, ANA C.C.; SCARAMUCCI, TAIS. Er,Cr:YSGG laser associated to fluoride on the control of dentin erosion progression. In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser in Dentistry, 2018. p. 88-88.

    Abstract: 1) Introduction: The combination between high power lasers and fluoride may potentially control the progression of dentin erosion. Therefore, the aim of this study was to evaluate the effect of Er,CrYSGG laser, associated to fluoride application, in the control of dentin erosion. 2) Materials and Methods: Dentin slabs were embedded into acrylic resin, flattened and polished. The specimens (n=10) were previously eroded (10min immersion in 1% citric acid solution) and randomly allocated into the experimental groups, according to the following treatments: control (no treatment); acidulated phosphate fluoride (APF) gel (1.23% F, 1min); Er,Cr:YSGG laser irradiation (parameter 1: 0.25W, 20Hz, 2.8J/cm2); Er,Cr:YSGG loser irradiation (parameter 2: 0.50W, 20Hz, 5.7J/cm2); APF gel+Er,Cr:YSGG laser parameter 1 and; APF gel+Er,Cr:YSGG laser parameter 2. After, they underwent on erosion-remineralization cycling, consisting of a 5min immersion into 0.3% citric acid, followed by 60min exposure to artificial saliva. This procedure was repeated 4x/day, for 5 days. Surface loss (SL, in μm) was determined with optical profilometry. The specimens were analyzed by environmental scanning electron microscopy (n=3). Data were statistically analyzed (α=0.05). 3) Results: None of the groups significantly differed from the control group, except for the APF group. APF gel presented the lowest SL, not differing from Er,Cr.YSGG laser (parameter 1) and APF gel+Er,Cr:YSGG laser (parameter 1). Selective structure removal was observed for the laser-treated groups. 4) Conclusions: None of the Er,Cr:YSGG laser parameters were effective in the control of dentin erosion. The laser was also not able to enhance the protection of fluoride against dental erosion.

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  • IPEN-DOC 18453

    YOSHIKAWA, HELENICE Y.; DAGUANO, JULIANA K.M.B.; PEREIRA, DAISA L. ; ZEZELL, DENISE M. ; ANA, PATRICIA A. . Effects of Er,Cr:YSGG laser and a bioactive glass on root caries remineralization. In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser in Dentistry, 2018. p. 87-88.

    Abstract: Considering the aging of the population, the greater exposure of the root surfaces and the higher caries risk in these surfaces, the development of strategies that efficiently remineralize root caries lesions in a long-lasting way is strictly necessary. This in vitro blind randomized study evaluated the potential of remineralization of root caries lesions promoted by Er,Cr:YSGG laser irradiation (2.78 μm) associated with a bioactive glass (Biosilicate ®). 60 bovine root dentin slabs with incipient caries lesions were distributed in 6 experimental groups {n:::15l, in order to be treated with laser irradiation (0.25W, 12.5 mJ/pulse, 2.8 J/cm2, 20 Hz, without refrigeration), application of Biosilicate® or association of both. After the treatments, the samples were subjected to an 8-day pH-cycling regimen, and further evaluated by Fourier transformed infrared spectroscopy {FTIR), optical coherence tomography (OCT) and scanning electron microscopy. The data were statistically analyzed at a 5% significance level. The Biosiljcate ® promoted the formation of carbonated hydroxyapatite even before loser irradiation, which was better retained after demineralization in loser irradiated group. The Biosilicote® and the la ser irradiation alone provided the remineralization of the root dentin in a similar way to that promoted by the topical application of acidulated phosphate fluoride, since all groups had comparable optical attenuation coefficients. The association of the Biosilicate® with the loser irradiation showed higher optical attenuation coefficient than the other experimental groups. It was concluded that the association of Biosilicote® with laser irradiation promoted a synergistic effect, augmenting the remineralization of root dentin and preventing the progression of caries.

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  • IPEN-DOC 18341

    PEREIRA, DAISA L. ; GOMES, GABRIELA V. ; SUGAHARA, VANESSA M.L.; SCAPIN, MARCOS A. ; ANA, PATRICIA A. ; ARANHA, ANA C.C.; ZAMATARO, CLAUDIA B. ; ZEZELL, DENISE M. . Nd:YAG laser irradiation of darkened dental enamel by means of dentrifice use. In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser in Dentistry, 2018. p. 87-87.

    Abstract: As the world population is growing older, dental erosion became a real concern on dentistry. Optical Coherence Tomography and X-Ray fluorescence were used to analyze enamel samples covered by black dentifrice as photoabsorber irradiated with NdYAG laser, then submitted to an erosive cycling. Heat injury risk in deeper tissue decreases because of the dentifrice dark pigment, when the most of photons are absorbed in the surface. Sixty Bmm2 blocks of bovine enamel, were randomized into 4 groups: G1- untreated; G2- treated with acidulated phosphate fluoride (APF, [FJ::1.23%, pH::3.3 to 3.9); G3- irradiated with Nd:YAG laser (1064nm, 0.6W, 10Hz- Lares Research®) using a coal paste as photoabsorber; G4- irradiated with Nd:YAG laser (1064nm, 0.6W, 10Hz), using a black dentifrice (Black is White, Curaprox®). All samples were submitted to a 3-day erosive demineralization (Citric acid 1%, pH::3.6, 5min, 2x/day) under agitation, and remineralization cycling (artificial saliva, pH::7, 120minJ. After treatments and pH cycling, the [Ca]/[P] ratio decreased in the laser irradiated groups. The samples were evaluated by OCT before and after treatment and after erosive cycling. OCT measurements found smaller lesion depths in laser irradiated groups than in the other groups and there were statistically significant differences between G3 and G4 groups (p<0.05). Heating promoted by Nd:YAG laser irradiation changed the morphological and crystallographic enamel surface properties and has shown to be a promissory alternative to prevent erosion.

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  • IPEN-DOC 17850

    LOPES, MONICA S.; PEREIRA, DAISA L. ; MOTA, CLAUDIA C.B.O.; ANA, PATRICIA A. ; ZEZELL, DENISE M. ; GOMES, ANDERSON S.L.. Shear bond strength of lingual brackets on enamel surface submitted to acid-etching or Nd:YAG laser irradiation. In: LASER DENTISTRY WORLD CONGRESS, 16th; DGL ANNUAL MEETING, 27th; INTERNATIONAL WALED CONGRESS, 6th, October 1-3, 2018, Aachen, Germany. Abstract... Aachen, Germany: International Society for Laser Dentistry, 2018. p. 82-82.

    Abstract: The patient demand for aesthetic orthodontic solutions is driving for use of lingual brackets and laser irradiation can prevent dental caries in this region. This in vitro study is the first one in literature that aimed to quantify the shear bond strength (SBS) on direct lingual b rackets bonding after different enamel surface pre-treatments. 75 bovine incisor teeth were randomized in 5 groups (n=15): G1- untreated; G2- treated with acidulated phosphate fluoride gel (APF-gel, [F-] =1.23%, pH=3.3 to 3.9); G3- conditioned with 37% phosphoric acid (Condoc 37%, FGM, Brazil) and treated with APF-gel; G4- irradiated with Nd:YAG loser (1064nm, 0.6W, 10Hz- Laser Research) and treated APF-gel; GS- irradiated with Nd:YAG laser + conditioned with 37% phosphoric acid + treated with APF-gel. The positioning of the brackets was standardized during the bonding procedure using a positioner and Transbond XT adhesive (3M Unitek, USA) was used. After bonding, all samples were thermocycled (500 cycles between SoC and 55°C) and submitted to a 48h cariogenic challenge. After cycling, the samples were tested for shear bond strength (SBS) in a universal testing machine (0.5mm/min). SBS test values were statistically higher (p<0.05) in the G3 and G5 groups when compared to the other groups. This study showed that the Nd:YAG loser irradiation improved dental adhesion and increased the mechanical resistance of the enamel because the heating promoted by Nd:YAG laser irradiation changed the morphological and crystallographic properties of enamel; in this way, this treatment also offers the advantage to prevent caries around brackets.

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A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.