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Navegação Periódicos - Artigos por Agências de fomento "International Atomic Energy Agency (IAEA)"

Navegação Periódicos - Artigos por Agências de fomento "International Atomic Energy Agency (IAEA)"

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  • IPEN-DOC 26393

    FERREIRA, EDUARDO G.A. ; MARUMO, JULIO T. ; FRANCO, MARGARETH K.K.D. ; YOKAICHIYA, FABIANO; VICENTE, ROBERTO . 10000 years cement: Can hydrated cement last as much as long-lived radionuclides?. Cement and Concrete Composites, v. 103, p. 339-352, 2019. DOI: 10.1016/j.cemconcomp.2019.05.016

    Abstract: This review is focused on the long-term performance of cementitious materials in a repository for radioactive waste. During the last few years, the disposal of disused sealed radioactive sources (DSRS) in a borehole type repository has been studied by many countries. The borehole concept is particularly useful to dispose of spent nuclear fuel and DSRS. In boreholes for DSRS, cementitious materials are intended to be used as structural material, immobilization matrix and as backfill. The understanding of the performance of these materials is essential to ensure the safety of the facilities during their required lifetime, from centuries to many thousands of years, depending on the initial activity and half-life of the waste. This review approaches the behavior of the cement from the hydration and hardening to the long-term processes that can affect its durability. Three main causes of failure of repository-engineered barriers are recognized: a) the formation of a preferential pathway for the migration of the contained radionuclides to the biosphere; b) loss of resistance and cohesion of the structural cementitious material; and c) the increase in the corrosion processes of the metallic components of the structures that affect the overall containment of the facility.

    Palavras-Chave: cement industry; portland cement; radioactive wastes; geologic formations; underground disposal; performance; chemical composition; mineralogy; radiations; magnetic fields; hydration

  • IPEN-DOC 25206

    FREITAS, LUCAS F. de ; VARCA, GUSTAVO H.C. ; BATISTA, JORGE G. dos S. ; LUGAO, ADEMAR B. . An overview of the synthesis of gold nanoparticles using radiation technologies. Nanomaterials, v. 8, n. 11, 2018. DOI: 10.3390/nano8110939

    Abstract: At a nano-level, optical properties of gold are unique and gave birth to an emerging platform of nanogold-based systems for diverse applications, because gold nanoparticle properties are tunable as a function of size and shape. Within the available techniques for the synthesis of gold nanoparticles, the radiolytic synthesis allows proper control of the nucleation process without the need for reducing agents, in a single step, combined or not with simultaneous sterilization. This review details and summarizes the use of radiation technologies for the synthesis and preparation of gold nanoparticles concerning fundamental aspects, mechanism, current pathways for synthesis and radiation sources, as well as briefly outlines final applications and some toxicity aspects related to nanogold-based systems.

    Palavras-Chave: gold; nanoparticles; gamma radiation; electron beams; x-ray sources; radiolysis; nanotechnology; medicine; diagnostic uses; ionizing radiations

  • IPEN-DOC 27582

    LIMA, CAROLINE S.A. de ; BALOGH, TATIANA S. ; VARCA, JUSTINE P.R.O. ; VARCA, GUSTAVO H.C. ; LUGAO, ADEMAR B. ; CAMACHO-CRUZ, LUIS A.; BUCIO, EMILIO; KADLUBOWSKI, SLAWOMIR S.. An updated review of macro, micro, and nanostructured hydrogels for biomedical and pharmaceutical applications. Pharmaceutics, v. 12, n. 10, p. 1-28, 2020. DOI: 10.3390/pharmaceutics12100970

    Abstract: Hydrogels are materials with wide applications in several fields, including the biomedical and pharmaceutical industries. Their properties such as the capacity of absorbing great amounts of aqueous solutions without losing shape and mechanical properties, as well as loading drugs of different nature, including hydrophobic ones and biomolecules, give an idea of their versatility and promising demand. As they have been explored in a great number of studies for years, many routes of synthesis have been developed, especially for chemical/permanent hydrogels. In the same way, stimuli-responsive hydrogels, also known as intelligent materials, have been explored too, enhancing the regulation of properties such as targeting and drug release. By controlling the particle size, hydrogel on the micro- and nanoscale have been studied likewise and have increased, even more, the possibilities for applications of the so-called XXI century materials. In this paper, we aimed to produce an overview of the recent studies concerning methods of synthesis, biomedical, and pharmaceutical applications of macro-, micro, and nanogels.

    Palavras-Chave: hydrogels; drugs; synthesis; cross-linking; skin; animal tissues; gamma radiation

  • IPEN-DOC 27852

    AQUINO, S. ; LIMA, J.E.A.; BORRELY, S.I. . Bioburden proliferation in vehicle air filters waste: the use of gamma radiation on fungal decontamination. Brazilian Journal of Radiation Sciences, v. 9, n. 1A, p. 1-14, 2021. DOI: 10.15392/bjrs.v9i1A.1254

    Abstract: This study aimed to analyze the fungal contamination of air-conditioning filters waste (n=20) as an indicator of Quality Air Indoor from different car models, that were collected from 10 exchange stations located in the South, North, West, Downtown and East, of the city of São Paulo in São Paulo State, Brazil, during the period from October 2017 to November 2018. Sampling of filter particles (33 fragments of 10 × 10-mm size) were plated onto solidified Potato Dextrose agar in Petri dishes. The samples were incubated for 7 days at 25 °C and were stored in a standard Biochemical Oxygen Demand incubator, for growth of fungal cultures. After incubation, the fungal culture in the plates was evaluated, and the total counting of infected fragments was expressed as a percentage. The fungi were examined by Lactophenol blue solution staining for microscopy. All samples were contaminated with various fungal genera, including Aspergillus, Alternaria, Cladosporium, and Penicillium. The study also aimed to evaluate the fungal enumeration in the samples that were irradiated with dose of 10 kGy to fungal decontamination of air-conditioning filters waste. Of total samples, 50% were completed decontaminated, but some genera such as Aspergillus, Penicillium, Rhizopus, Cladosporium and yeasts demonstrated radioresistance at the dose of 10 kGy. The only yeast called Rhodotorula showed an increase in growth after the irradiation process.

    Palavras-Chave: air conditioning; air filters; air quality; automobiles; cobalt 60; contamination; decontamination; fungi; wastes

  • IPEN-DOC 29846

    AQUINO, S. ; LIMA, J.E.A.; BORRELY, S.I. . Combined application of gamma radiation, cleaning and chemical sanitizers in decontamination of vehicle air conditioning filters. Brazilian Journal of Radiation Sciences, v. 11, n. 2, p. 1-11, 2023. DOI: 10.15392/2319-0612.2023.2244

    Abstract: This work aimed to analyze the fungal contamination of air-conditioning filter waste (n=15) as an indicator of Quality Air Indoor from different car models in São Paulo city in São Paulo State, Brazil, during the period from October 2018 to July 2019. Three different treatments were used for the decontamination of car air conditioning filters, such as mechanical vacuum cleaning (I), vacuum cleaning and use of sanitizing product (II), and sanitizing product associated with radiation treatment at a dose of 17 kGy (III). After the treatments, microbiological analyses were performed and samples were plated in Petri dishes containing Sabouraud agar transferred by Swabs, and incubated for 7 days at 25 °C. The Petri dishes were stored in a standard Biochemical Oxygen Demand incubator, for the growth of fungal cultures. After incubation, the fungal cultures were evaluated, and the fungal counting was expressed in unit-forming colonies (UFC) and frequency in samples (%). The fungi were examined by lactophenol blue solution staining for microscopy. All samples of treatment I and II were contaminated with various fungal genera and high bioburden, namely (treatment I) Alternaria alternata, Aspergillus flavus, A. niger, Cladosporium spp., Fusarium spp., Mucor spp., Nigrospora spp., Not Sporulated Fungi (NSF), Penicillium spp., Rhizopus spp., Rhodotorula spp., Trichoderma spp. and yeasts. Treatment II showed Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. ochraceus, Cladosporium spp., Mucor spp., NSF, Penicillium spp., Phoma spp., Rhizopus spp., Rhodotorula spp., Trichoderma spp., and yeasts. Treatment III presented NSF and yeasts, with 80% of material decontamination.

  • IPEN-DOC 27201

    FREITAS, LUCAS F. de ; CRUZ, CASSIA P.C. da ; CAVALCANTE, ADRIANA K. ; BATISTA, JORGE G. dos S. ; VARCA, GUSTAVO H.C. ; MATHOR, MONICA B. ; LUGAO, ADEMAR B. . Comparison between gold nanoparticles synthesized by radiolysis and by EGCG-driven gold reduction. Radiation Physics and Chemistry, v. 174, p. 1-9, 2020. DOI: 10.1016/j.radphyschem.2020.108959

    Abstract: Radiolytic synthesis and phytochemical-driven gold reduction for the generation of nanoparticles are successful examples of Green Chemistry applied for nanomaterials. The present work compares these two green approaches focusing on hydrodynamic size, stability over time, optical properties and toxicity in NIH 3T3 (ATCC® CRL- 1658™) cells and Danio rerio (Zebra Fish). The radiolytic synthesis was performed by mixing 1 mM NaAuCl4; polyvinyl pyrrolidone 0.5%, AgNO3 6×10−5 M, propan-2-ol 0.2 M and acetone 0.06 M, followed by irradiation at 15 kGy (5 kGy h−1, 60Co source). The EGCG-functionalized nanoparticles were synthesized by mixing 1.6 mM of Au with 0.8 mM of EGCG in phosphate buffer (10 mM) for 2 h. Both methods yield the formation of gold nanoparticles featuring plasmon resonance bands at 520–530 nm, polydispersity above 0.3 was relevant only for the radiolytic protocol. Regarding stability over time, after 30 days, the nanoparticles synthesized radiolytically presented no relevant size changes, while some aggregation was observed for the EGCG-particles. The same nanoparticles demonstrated a lack of stability in high ionic strength medium. Slight toxicity was observed for the EGCG-nanoparticles in Danio rerio, with an IC50 calculated as 40.49%, while no IC50 was established within the concentration range of radiolysis-AuNPs used in this study. In conclusion, both green methods generated nanoparticles with good control of size and optical properties, especially via reduction by EGCG. However, the stability and toxicity results were found to be more promising for the radiolytically synthesized gold nanoparticles.

    Palavras-Chave: gold; nanoparticles; synthesis; chemistry; ecology; polyphenols; fishes

  • IPEN-DOC 28665

    ANDRADE, MARCIO S. ; ISHIKAWA, OTAVIO H. ; COSTA, ROBSON S. ; SEIXAS, MARCUS V.S. ; RODRIGUES, RITA C.L.B.; MOURA, ESPERIDIANA A.B. . Development of sustainable food packaging material based on biodegradable polymer reinforced with cellulose nanocrystals. Food Packaging and Shelf Life, v. 31, p. 1-10, 2022. DOI: 10.1016/j.fpsl.2021.100807

    Abstract: The increased environmental impact and sustainability issues related to conventional food packaging have gained attention and led to a global concern. The massive consumption of conventional food packaging has increased disposal of non-eco-friendly packaging waste, severely damaging the environment. The replacement by sustainable packaging is an important alternative to reduce the enormous volume of plastic waste. In this work, bionanocomposite films composed of PBAT/PLA blend and cellulose nanocrystals (CNCs) extracted from agro-waste were investigated. Characterization of CNCs confirmed that nanocrystals were obtained. Bionanocomposite films presented better hydrophobic character and thermal stability than the blend film. In addition, the tensile strength, elongation at break, and Young's modulus was around 52%, 29%, and 118%, respectively, higher than blend films. These mechanical values were comparable to values of commercial plastic materials that are extensively used in food packaging. Thus, the prepared bionanocomposite films might be an interesting alternative to produce sustainable food packaging materials.

    Palavras-Chave: cellulose; nanocrystals; food; packaging; nanocomposites; sugar cane; bagasse; agricultural wastes

  • IPEN-DOC 27887

    PRIMO, C.O. ; ANGELOCCI, L.V. ; KARAM JUNIOR, D.; ZEITUNI, C.A. ; ROSTELATO, M.E.C.M. . Dose-rate constant and air-kerma strength evaluation of a new 125I brachytherapy source using Monte-Carlo. Brazilian Journal of Radiation Sciences, v. 9, n. 1A, p. 1-11, 2021. DOI: 10.15392/bjrs.v9i1A.1441

    Abstract: Brachytherapy is a modality of radiotherapy which treats tumors using ionizing radiation with sources located close to the tumor. The sources can be produced from several radionuclides in various formats, such as Iodine-125 seeds and Iridium-192 wires. In order to produce a new Iodine-125 seed in IPEN/CNEN and ensure its quality, it is essential to describe the seed dosimetry, so when applied in a treatment the lowest possible dose to neighboring healthy tissues can be reached. The report by the AAPM’s Task Group 43 U1 is a document that indicates the dosimetry procedures in brachytherapy based on physical and geometrical parameters. In this study, dose-rate constant and air-kerma strength parameters were simulated using the Monte Carlo radiation transport code MCNP4C. The air-kerma strength is obtained from an ideal modeled seed, since its actual value should be measured for seeds individually in a specialized lab with a Wide-Angle Free-Air Chamber (WAFAC). Dose-rate constant and air-kerma strength are parameters that depends on intrinsic characteristics of the source, i.e. geometry, radionuclide, encapsulation, and together they define the dose-rate to the reference point. Radial dose function describes the dose fall-off with distance from the source. This study presents the values found for these parameters with associated statistical uncertainty, and is part of a larger project that aims the full dosimetry of this new seed model, including experimental measures.

    Palavras-Chave: brachytherapy; computerized simulation; dose rates; dosimetry; iodine 125; kerma; monte carlo method

  • IPEN-DOC 29881

    BARROS, JANETTY J.P. ; OLIVEIRA, RENE R. ; LUNA, CARLOS B.B.; WELLEN, RENATE M.R.; MOURA, ESPERIDIANA A.B. . Effectiveness of modified lignin on poly(butylene adipateco-terephthalate)/poly(lactic acid) mulch film performance. Journal of Applied Polymer Science, v. 140, n. 46, p. 1-12, 2023. DOI: 10.1002/app.54684

    Abstract: In this work, the biodegradable poly(butylene adipate-co-terephthalate) (PBAT)/ poly(lactic acid) (PLA) blend (ECOVIO®) and lignin, a renewable and biodegradable natural polymer with high UV absorption and modified by gamma radiation were used to produce agriculture mulch films. Lignin was gammairradiated at 30 and 60 kGy. The irradiated and non-irradiated lignin content of 2 wt% was incorporated into PBAT/PLA blend matrix using a twin-screw extruder and extrusion blown film to prepare flexible films. PBAT/PLA/LIGNIN films were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), tensile tests, contact angle, and UV–Vis analysis. FTIR spectra showed partial miscibility between PBAT/PLA and lignin, being intensified in irradiated lignin compounds. The DSC and XRD results confirmed that the degree of crystallinity of the blends was not significantly influenced by lignin addition. FE-SEM images showed better dispersion and miscibility in PBAT/PLA/Irradiated lignin. Miscibility improvement provided by irradiated lignin promoted better mechanical properties, mainly with lignin irradiated at 60 kGy. PBAT/PLA/LIGNIN films containing 2 wt% showed excellent UV-barrier property and greater hydrophobicity. Summing up, incorporation of low contents of irradiated lignin could be an interesting alternative to produce biodegradable UV-blocking agriculture mulch films.

  • IPEN-DOC 29057

    BARROS, JANETTY J.P. ; SOARES, CARLOS P. ; MOURA, ESPERIDIANA A.B. de ; WELLEN, RENATE M.R.. Enhanced miscibility of PBAT/PLA/lignin upon γ-irradiation and effects on the non-isothermal crystallization. Journal of Applied Polymer Science, v. 139, n. 45, p. 1-18, 2022. DOI: 10.1002/app.53124

    Abstract: Lignin is natural and renewable polymer, the second most abundant on Earth. Properly used it can reduce synthetic and oil based materials in addition to contributing to the biodegradable systems. In this work, the kraft lignin was subjected to gamma radiation at absorbed doses of 30, 60, and 90 KGy in order to increase the interaction with “Poly(butylene adipate-co-terephthalate) (PBAT)/Poly(lactic acid) (PLA)” blend (Ecovio®). PBAT/PLA/lignin blends with 10% of the weight of lignin were produced by extrusion using twin-screw extruder and characterized by Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), and Field emission scanning electron microscopy (FE-SEM). FTIR spectra showed partial miscibility between PBAT/PLA and lignin, most due to the hydrogen bond between PBAT/PLA carbonyl and lignin hydroxyl, being intensified in irradiated lignin compounds. As evidenced on DSC scans, in PBAT/PLA/irradiated lignin the crystallization peak was shifted to lower temperatures and the crystallization rate decreased. Crystallization kinetics was modeled using Pseudo Avrami, and isoconversional models of Friedman and Vyazovkin. Pseudo-Avrami displayed linearity deviation at beginning and crystallization ending due to the nucleation and secondary crystallization, while from Friedman and Vyazovkin the activation energy (Ea) was higher for PBAT/PLA/irradiated lignin 30 KGy, characterizing crystallization with higher energy consumption. FE-SEM images showed better dispersion and miscibility in PBAT/PLA/irradiated lignin. The results indicate that the irradiation of Kraft lignin promotes miscibility and compatibility of PBAT/PLA/lignin.

    Palavras-Chave: crystallization; polymers; calorimetry; irradiation; kinetics

  • IPEN-DOC 29064

    BARBOSA, ANDREY S. ; BIANCOLLI, ANA L.G. ; LANFREDI, ALEXANDRE J.C.; RODRIGUES JUNIOR, ORLANDO ; FONSECA, FABIO C. ; SANTIAGO, ELISABETE I. . Enhancing the durability and performance of radiation-induced grafted low-density polyethylene-based anion-exchange membranes by controlling irradiation conditions. Journal of Membrane Science, v. 659, p. 1-12, 2022. DOI: 10.1016/j.memsci.2022.120804

    Abstract: This study presents a systematic analysis of the influence of irradiation conditions (absorbed dose, temperature, and atmosphere) on the physicochemical properties of radiation-induced grafted anion-exchange membranes (AEMs) based on low-density polyethylene (LDPE). Detailed characterization of the polymeric electrolytes shows striking effects of the irradiation conditions on the AEM properties. The LDPE films are irradiated both at room temperature (RT) and low temperature (LT, ∼ −10 °C). At each temperature, samples are irradiated in air as well as nitrogen. By lowering the sample temperature from RT to LT during irradiation in air it is possible to obtain a threefold increase in the degree of grafting (DoG). The higher DoG reflects in the OH− conductivity (σ) of the AEM irradiated at LT, which exhibits σ (T = 80 °C) = 215 mS cm−1, while the sample prepared at RT and air has σ (T = 80 °C) = 127 mS cm−1. Such high conductivity of the LT irradiated LDPE-AEM results in high-performance anion-exchange membrane fuel cell (AEMFC) with enhanced stability, as inferred from the time dependence of σ (T = 60 °C) measurements. The experimental results evidence that the control of both the irradiation temperature and the atmosphere diminishes the degradation effects caused by the radiation. Therefore, the present study advances the understanding of the role played by the irradiation process on the final properties of radiation-induced grafted LDPE-based AEMs and offers new possibilities to guide future developments for anion-exchange membranes.

    Palavras-Chave: polyethylenes; density; anions; ion exchange; membranes; fuel cells

  • IPEN-DOC 27861

    TAPPIZ, BRUNO ; MOREIRA, EDSON G. . Expanded uncertainty assessment in fish samples analyzed by INAA and AAS. Brazilian Journal of Radiation Sciences, v. 9, n. 1A, p. 1-14, 2021. DOI: 10.15392/bjrs.v9i1A.1314

    Abstract: Measurement uncertainty was estimated following the EURACHEM guide (Quantifying Uncertainty in Analytical Measurement) for the elements As, Br, Cl, Co, Cr, Cs, Fe, K, Mg, Mn, Na, Rb, Sb, Se and Zn determined by In-strumental Neutron Activation Analysis (INAA) and for the elements Cd, Hg and Pb determined by Atomic Absorption Spectrometry (AAS) in the fillet of the most consumed fish species at São Paulo city, Brazil. INAA expanded uncertainties ranged from 1.0 to 21% and the main contributions were due the counting statistics of sample and pipetted standards. For AAS, expanded uncertainties ranged from 6.5 to 13% and the main contri-butions were associated to the calibration curves. Uncertainty results were compared with the standard devia-tions of the mass fraction in the fishes (n = 10). Due to the wide variability in the mass fraction in the analyzed fish tissues, explained by factors such gender, age, fat content and fishing location of the specimens of each spe-cies, standard deviations were greater than expanded uncertainties, which means that the natural variability of the elements determined is greater than the data dispersion associated with the analytical techniques. Hence the used techniques were adequate for the fish fillet samples analyses.

    Palavras-Chave: absorption spectroscopy; data covariances; evaluation; fishes; neutron activation analysis; toxicity

  • IPEN-DOC 29839

    ESQUIVEL-HERNANDEZ, GERMAIN; SANCHEZ-MURILLO, RICARDO; VILLALOBOS-CORDOBA, DIEGO; MONTEIRO, LUCILENA R. ; VILLALOBOS-FORBES, MARIO; SANCHEZ-GUTIERREZ, ROLANDO; COTRIM, MARYCEL E.B. ; MATIATOS, IOANNIS. Exploring the acid neutralizing effect in rainwater collected at a tropical urban area: Central Valley, Costa Rica. Atmospheric Pollution Research, v. 14, n. 9, p. 1-12, 2023. DOI: 10.1016/j.apr.2023.101845

    Abstract: We report on the chemical and the carbon isotopic composition of dissolved inorganic carbon (DIC) of rainwater collected between May and October 2020 in the Central Valley, Costa Rica. Precipitation samples were collected daily (N = 55) and analyzed for major ions, DIC, and δ13CDIC. Significant correlation (p < 0.05) between main acidic (SO4 2− and NO3 − ) and major alkaline (Ca2+ and NH4 +) species confirmed a very effective acid neutralization effect in rainwater (average pH: 5.90 ± 0.74). Significant temporal variations (p < 0.05) of δ13CDIC indicated the contribution of carbonate salts in rainwater from May to October but also CO2 dissolution at the beginning of the wet season (May), probably due to increased CO2 emissions from soil degassing. Temporal changes of Ca2+ neutralization factors followed the observed changes in δ13CDIC, which confirmed the high buffer capacity of precipitation in our study. HYSPLIT analysis also revealed long-range contributions of pedogenetic carbonates (e. g., Saharan dust) responsible for the acid neutralization capacity of rainwater (e.g., from July to September). Principal component analysis showed that four main factors explain 65% of the variance are: i) acid neutralization processes (Ca2+ neutralization factor), ii) marine salts (Cl− , Na+), iii) fossil fuels (SO4 2− , NO3 − ), and iv) agriculture/fertilizers (NO3 − , NH4 +, K+). Our study demonstrated that a combined approach of chemical, isotope, and statistical analysis techniques can help unravel the mechanism of acid neutralization of rainwater in tropical urban areas. This information has strong implications for future studies related with the impact of acid deposition on ecosystem functioning, water quality, and infrastructure degradation.

  • IPEN-DOC 28856


    Abstract: The rapidly growing interest in the application of nanoscience in the future design of radiopharmaceuticals and the development of nanosized radiopharmaceuticals in the late 2000′s, resulted in the creation of a Coordinated Research Project (CRP) by the International Atomic Energy Agency (IAEA) in 2014. This CRP entitled ‘Nanosized delivery systems for radiopharmaceuticals’ involved a team of expert scientist from various member states. This team of scientists worked on a number of cutting-edge areas of nanoscience with a focus on developing well-defined, highly effective and site-specific delivery systems of radiopharmaceuticals. Specifically, focus areas of various teams of scientists comprised of the development of nanoparticles (NPs) based on metals, polymers, and gels, and their conjugation/encapsulation or decoration with various tumor avid ligands such as peptides, folates, and small molecule phytochemicals. The research and development efforts also comprised of developing optimum radiolabeling methods of various nano vectors using diagnostic and therapeutic radionuclides including Tc-99m, Ga-68, Lu-177 and Au-198. Concerted efforts of teams of scientists within this CRP has resulted in the development of various protocols and guidelines on delivery systems of nanoradiopharmaceuticals, training of numerous graduate students/post-doctoral fellows and publications in peer reviewed journals while establishing numerous productive scientific networks in various participating member states. Some of the innovative nanoconstructs were chosen for further preclinical applications—all aimed at ultimate clinical translation for treating human cancer patients. This review article summarizes outcomes of this major international scientific endeavor.

    Palavras-Chave: nanoparticles; drug delivery; radiopharmaceuticals; polymers; radioisotopes; theranostics

  • IPEN-DOC 29024

    PASSOS, RICARDO G.; MATIATOS, IOANNIS; MONTEIRO, LUCILENA R. ; ALMEIDA, RAFAEL S.S.P.; LOPES, NILVA P.; CARVALHO FILHO, CARLOS A.; COTA, STELA D.S.. Imprints of anthropogenic air pollution sources on nitrate isotopes in precipitation in a tropical metropolitan area. Atmospheric Environment, v. 288, p. 1-14, 2022. DOI: 10.1016/j.atmosenv.2022.119300

    Abstract: Identifying the origin of NOx emissions, their transformation into nitrate (NO3−) and its atmospheric deposition is important to better understand the impacts of air pollution on the environment and human health, on a local and regional scale. We measured nitrate isotopes (δ15N, δ18O of NO3−) in precipitation samples in a tropical station in Brazil in 2019–2020 and combined them with chemical, geospatial and meteorological data to trace NOx sources towards their wet deposition as NO3−. A total wet N deposition of ∼12 kg N/ha.year showed significant N air pollution, out of which the relative contribution of NO3−-N was ∼37% (4.6 kg NO3−-N/ha.year). The δ15N–NO3- values in precipitation ranged from −8.5 to +4.1‰, with a volume-weighted mean (VWM) value of −3.0 ± 2.7‰, whereas the δ18O–NO3- values ranged from +25.9 to +63.5‰ with a VWM value of +53.3 ± 7.3‰. The δ15N–NO3- results combined with air mass backward trajectory analysis and geospatial mapping revealed that the NOx emissions in Belo Horizonte originated from: vehicles and industries from the urban and industrialized areas, biomass burning related to wildfires, and ship emissions from the coastal areas. The temporal variation of δ15N, δ18O of NO3− values was attributed to NOx source variability and transformation processes. The use of integrated methods to evaluate the imprints of anthropogenic air pollution sources in Brazil will contribute to inform NOx source management strategies and improve air and water quality.

    Palavras-Chave: stable isotopes; washout; nitrogen oxides; geographic information systems; air pollution; pollution sources

  • IPEN-DOC 29712

    SILVA, THALITA T. ; JACINAVICIUS, FERNANDA R.; PINTO, ERNANI; BORRELY, SUELI I. . Intracellular microcystins degradation and acute toxicity decrease towards Daphnia similis by low electron-beam irradiation doses. Algal Research, v. 72, p. 1-7, 2023. DOI: 10.1016/j.algal.2023.103086

    Abstract: Ionizing radiation has attracted attention due to its ability to inhibit pathogens and microorganisms, with low doses reported as being able to degrade cyanotoxins and inhibit toxic cyanobacteria growth. In this context, the aim of the present study was to investigate how electron beam irradiation (EBI) applied at doses between 1 and 10 kGy affect intracellular and extracellular microcystin variants. Effects on M. aeruginosa culture recovery, as well as changes in physico-chemical cyanobacterial suspension parameters and water quality alterations were assessed through ecotoxicity assays. The findings indicate that doses over 2 kGy may are lethal to M. aeruginosa even at 48 h post-irradiation. Concerning physico-chemical parameters, exposure to 2–5 kGy doses decrease pH values and later stabilizing. At least 50 % of intracellular MC led to significant degradation of all variants at 3 kGy. No acute toxicity effects were observed in Daphnia similis exposed to sample supernatants. Statistically significant differences were observed when cladocerans were exposed to M. aeruginosa cells treated with EBI doses ranging from 3 to 10 kGy compared to non-treated cyanobacterial suspensions. These findings suggest that low EBI radiation doses are suitable for the control of toxic cyanobacteria in water treatment processes, providing a less toxic environment compared to non-treated solutions.

    Palavras-Chave: daphnia; toxicity; cyanobacteria; electron beams; irradiation; ionizing radiations; oxidation

  • IPEN-DOC 28151

    SOWINSKI, SEBASTIAN; VARCA, GUSTAVO H.C. ; KADLUBOWSKI, SLAWOMIR; LUGAO, ADEMAR B. ; ULANSKI, PIOTR. A mechanistic approach towards the formation of bityrosine in proteins by ionizing radiation: GYG model peptide. Radiation Physics and Chemistry, v. 188, p. 1-8, 2021. DOI: 10.1016/j.radphyschem.2021.109644

    Abstract: One of the methods of protein crosslinking used in the synthesis of protein-based nanoparticles is the formation of bityrosine bridges, which may be achieved by the recombination of phenoxyl-type radicals in irradiated protein solutions. Radiation-induced formation of phenoxyl radicals in tyrosine is promoted in presence of H+. In this work, kinetics of this process and the influence of pH were studied by pulse radiolysis measurements of a model peptide H-Gly-Tyr-Gly-OH (GYG), which may help to solve questions raised for bigger, more complex systems in comparable conditions. The main route of phenoxyl radicals formation consists of the addition reaction of hydroxyl radical to the phenol ring on the tyrosine side-chain and proton catalyzed water molecule elimination. A similar effect was observed in studies of tripeptide solutions containing phosphate buffer. The presented data include time-resolved optical spectroscopy of transient species formed under pulse electron beam irradiation and a comparison of the kinetics of the phenoxyl radicals formation in samples at various pH and in presence of phosphate buffer. The postulated mechanism and obtained values of rate constants of the formation and decay of transient species were additionally checked by simple probabilistic simulations.

    Palavras-Chave: ionizing radiations; radiolysis; tyrosine; proteins

  • IPEN-DOC 27771

    ANGELOCCI, LUCAS V. ; SOUZA, CARLA D. de ; PANTELIS, EVAGGELOS; NOGUEIRA, BEATRIZ R. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Monte Carlo simulation to assess free space and end-weld thickness variation effects on dose rate for a new Ir-192 brachytherapy source. Applied Radiation and Isotopes, v. 173, p. 1-6, 2021. DOI: 10.1016/j.apradiso.2021.109709

    Abstract: A new Iridium-192 seed for brachytherapy is under development. Specific dose rate contribution by two different factors were evaluated: the effect from movement of the core in the free space within the seed and the effect of the end-weld thickness variation. Both were investigated through use of the Monte Carlo radiation transport code MCNP6 and an in-house routine programmed with MATLAB. Differences greater than 15% compared to results from the nominal seed were found near the source, indicating a significant dose variation.

    Palavras-Chave: calculation methods; monte carlo method; brachytherapy; iridium 192; seeds; dosimetry; source terms; dose rates

  • IPEN-DOC 27816

    AQUINO, SIMONE ; LIMA, JOSE E.A. de; REIS, TATIANA A. dos; CORREA, BENEDITO; BORRELY, SUELI I. . Mycoflora and DNA sequencing analysis of radioresistant fungi isolated from irradiated vehicular air conditioning filters collected in São Paulo, Brazil. Microbiology Research International, v. 9, n. 1, p. 1-15, 2021. DOI: 10.30918/MRI.91.21.011

    Abstract: Fungal bioburdens in filters from car air conditioning systems represent a potential risk of respiratory or pulmonary diseases to both passengers and drivers. The present study demonstrated high fungal contamination in air conditioning filters collected from fifty-seven vehicles from the city of São Paulo, Brazil. The filters samples were irradiated with 10, 15 and 20 kGy gamma ray doses with a cobalt-60 source. The presence of Aspergillus flavus, Penicillium glabrum and Fusarium incarnatum-equiseti remaining after the ionizing treatment with 10 and 15 kGy. The radioresistant pathogenic species was confirmed through genetic sequencing of the ITS, β-tubulin and calmodulin gene rDNA regions. The 20 kGy dose was efficient in inhibiting pathogenic fungi growth in all samples but promoted the fungal decontamination in 79% of the samples. These results and other efforts will enable ionizing radiation to become an important tool in contributing to the recycling of automotive vehicle air filters and in ensuring indoor air quality for both drivers and passengers.

    Palavras-Chave: ionizing radiations; air quality; indoor air pollution; vehicles; air conditioning; fungal diseases; air filters; air cleaning systems

  • IPEN-DOC 25801

    TAPPIZ, B. ; MOREIRA, E.G. . Neutron activation analysis characterization procedures for fish consumed at São Paulo city. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2A.710

    Abstract: The characterization of edible tissues of fishes consumed by humans is very important for determination of sev-eral toxic and potentially toxic elements, ensuring the food safety. The Instrumental Neutron Activation Analysis (INAA) comparative method allows the determination of several of these elements, as well as others, for example of nutritional character. This study is part of an International Atomic Energy Agency (IAEA) technical coopera-tion project of Latin America and Caribbean countries to ensure the quality of food and biomonitoring of con-taminants in shellfish and fishes. Ten specimens of 4 of the most consumed fish in São Paulo city: whitemouth croaker (Micropogonias Furnieri), smooth weakfish (Cynoscion learchus), common snook (Centropomus undeci-malis) and Brazilian sardine (Sardinella brasiliensis) were analyzed. Complete procedures for analysis, which includes purchase in the largest warehouse in Latin America, transport to the laboratory, storage, freeze-drying, milling, weighting and others preparations of the subsamples, and the short irradiation parameters for the de-termination of Br, Cl, K, Mg, Mn and Na are reported. Results obtained under the same irradiation conditions for reference materials (oyster and mussel tissues) for macro and microelements are presented and are in agreement with their certificates, which indicate that the performed analyses were appropriate. Regarding to the mass fraction values obtained for the fish samples, they were in agreement with the literature.

    Palavras-Chave: neutron activation analysis; fishes; brazil; contamination; gamma spectroscopy; quality assurance; quality management; high-purity ge detectors; radioisotopes; food; quality control

A pesquisa no RD utiliza os recursos de busca da maioria das bases de dados. No entanto algumas dicas podem auxiliar para obter um resultado mais pertinente.

É possível efetuar a busca de um autor ou um termo em todo o RD, por meio do Buscar no Repositório , isto é, o termo solicitado será localizado em qualquer campo do RD. No entanto esse tipo de pesquisa não é recomendada a não ser que se deseje um resultado amplo e generalizado.

A pesquisa apresentará melhor resultado selecionando um dos filtros disponíveis em Navegar

Os filtros disponíveis em Navegar tais como: Coleções, Ano de publicação, Títulos, Assuntos, Autores, Revista, Tipo de publicação são autoexplicativos. O filtro, Autores IPEN apresenta uma relação com os autores vinculados ao IPEN; o ID Autor IPEN diz respeito ao número único de identificação de cada autor constante no RD e sob o qual estão agrupados todos os seus trabalhos independente das variáveis do seu nome; Tipo de acesso diz respeito à acessibilidade do documento, isto é , sujeito as leis de direitos autorais, ID RT apresenta a relação dos relatórios técnicos, restritos para consulta das comunidades indicadas.

A opção Busca avançada utiliza os conectores da lógica boleana, é o melhor recurso para combinar chaves de busca e obter documentos relevantes à sua pesquisa, utilize os filtros apresentados na caixa de seleção para refinar o resultado de busca. Pode-se adicionar vários filtros a uma mesma busca.


Buscar os artigos apresentados em um evento internacional de 2015, sobre loss of coolant, do autor Maprelian.

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou pertinente.

95% do RD apresenta o texto completo do documento com livre acesso, para aqueles que apresentam o significa que e o documento está sujeito as leis de direitos autorais, solicita-se nesses casos contatar a Biblioteca do IPEN, .

Ao efetuar a busca por um autor o RD apresentará uma relação de todos os trabalhos depositados no RD. No lado direito da tela são apresentados os coautores com o número de trabalhos produzidos em conjunto bem como os assuntos abordados e os respectivos anos de publicação agrupados.

O RD disponibiliza um quadro estatístico de produtividade, onde é possível visualizar o número dos trabalhos agrupados por tipo de coleção, a medida que estão sendo depositados no RD.

Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).



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.

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.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.

2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

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.