Periódicos - Artigos

 

Submissões recentes

  • IPEN-DOC 25653

    SILVA, VILMARA R.M. da; VIANA, ITALLO E.L.; LOPES, RAQUEL M.; ZEZELL, DENISE M. ; SCARAMUCCI, TAIS ; ARANHA, ANA C.C.. Effect of Er,Cr:YSGG laser associated with fluoride on the control of enamel erosion progression. Archives of Oral Biology, v. 99, p. 156-160, 2019. DOI: 10.1016/j.archoralbio.2019.01.011

    Abstract: Objective: To evaluate the effect of Er,Cr:YSGG laser associated or not with acidulated phosphate fluoride (APF) on the control of enamel erosion progression. Design: Enamel slabs (4mm×4mm×2 mm) from bovine incisors were flattened, polished, and received a tape on their test surfaces, leaving a 4mm×1mm area exposed. Specimens were eroded (10 min in 1% citric acid solution) and randomly assigned into 8 experimental groups (n=10): Control (no treatment); F (APF gel, 1.23% F, pH 3.6–3.9); Er,Cr:YSGG laser irradiation (P1: 0.25 W, 20 Hz, 2.8 J/cm2, 56 W/cm2); Er,Cr:YSGG laser irradiation (P2: 0.50 W, 20 Hz, 5.7 J/cm2, 1136 W/cm2); Er,Cr:YSGG laser irradiation (P3: 0.75 W, 20 Hz, 8.5 J/cm2, 1704 W/cm2); F+Laser P1; F+Laser P2; F+Laser P3. Specimens were then subjected to erosive cycling (5 min immersion in 0.3% citric acid solution, followed by immersion in artificial saliva for 60 min; 4×/day for 5 days). At the end of cycling, surface loss (SL, in μm) was determined with optical profilometry. Selected specimens were further evaluated by environmental scanning electron microscopy (n=3). Data were analyzed using Kruskal-Wallis and Tukey tests (α=0.05). Results: Group F+Laser P2 had the lowest SL value, differing significantly from the control; however, with no significant difference from the other groups. All groups, except F+Laser P2, showed no significant difference in SL when compared with the control. An irregular and rough surface, suggestive of a melting action of laser, was observed on enamel in Laser P2 and F+Laser P2 groups. Conclusions: Association of the Er,Cr:YSGG laser in parameter 2 with fluoride was the only treatment capable of controlling the progression of enamel erosion.

    Icon

  • IPEN-DOC 25652

    DIAS-MORAES, MARCIA C. de ; LIMA, CASSIO A. ; FREITAS, ANDERSON Z. ; ARANHA, ANA C.C.; ZEZELL, DENISE M. . Using optical attenuation coefficient to monitor the efficacy of fluoride and Nd:YAG laser to control dentine erosion. Applied Sciences, v. 9, n. 7, 2019. DOI: 10.3390/app9071485

    Abstract: The present study evaluated the protective effects that are induced by fluoride and Nd:YAG laser irradiation to control dentine erosion. One hundred and twenty bovine dentine slabs were eroded with citric acid twice a day for a total period of 15 days. At day 10, the samples were randomly assigned into eight groups: C (Control); F (Fluoride); L1 (Nd:YAG laser, 1 W, 100 mJ, 79.5 J cm􀀀2); L2 (Nd:YAG laser, 0.7 W, 70 mJ, 55.7 J cm􀀀2); L3 (Nd:YAG laser, 0.5 W, 50 mJ, 39.7 J cm􀀀2); F + L1; F + L2; and, F + L3. Optical Coherence Tomography images were collected from the surface of the samples in order to monitor the alterations that were induced by erosion and the effectiveness of each treatment using the Optical Attenuation Coefficient (OAC). OAC values that were calculated for samples from groups C, F, L1, L3, FL1, and FL3 indicated no protective effects against the progression of erosive lesions. Samples from L2 and FL2 groups presented OAC values, indicating that laser irradiation under this condition did not induce the formation of craters on dentine tissue and promoted sufficient chemical and morphological changes to avoid the progression of dentine erosion.

    Icon

  • IPEN-DOC 25649

    PIVA, AMANDA M. da; TRIBST, JOAO P.; GONDIM, LAISA D.; RIBEIRO, ISABELLA L.; CAMPOS, FERNANDA; ARATA, ANELYSE ; SOUZA, RODRIGO O.. Y-TZP surface behavior under two different milling systems and three different accelerated aging protocols. Minerva Stomatologica, v. 67, n. 6, p. 237-245, 2018. DOI: 10.23736/S0026-4970.18.04138-9

    Abstract: BACKGROUND: To evaluate the influence of aging and milling system on zirconia surface roughness (SR) and phase transformation. METHODS: Eighty crowns were divided in two groups according to yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic milling system (CAD-Neodent or MAD-Zirkonzahn). The crowns were submitted to different aging protocols (N.= 10): 1) no aging; 2) autoclaving; 3) pH cycling; or 4) thermocycling. Next, the samples were submitted to an optical profilometry analysis to determine differences in the SR (mu m). An X-ray diffraction analysis (XRD) was performed to quantify the percentage of monoclinic phase transformation. SR data was analyzed by two-way ANOVA (alpha=0.5%). RESULTS: Aging protocol (P=0.42) and milling system (P=0.08) had no influence on the SR. However, the number of monoclinic phases was influenced by the autoclaving and pH cycling. CONCLUSIONS: The surface roughness of zirconia-based crowns was not influenced by low temperature degradation or milling system. Regarding the phase transformation, autoclaving and pH-cycling aging presented a monoclinic phase increase when compared to the control group and thermocycled groups.

    Icon

  • IPEN-DOC 25618

    AVILLA, LEONARDO S.; MACHADO, HELENA; ARAUJO-JUNIOR, HERMINIO I. de; MOTHE, DIMILA; ROTTI, ALLINE; OLIVEIRA, KAROLINY de; MALDONADO, VICTORIA; FIGUEIREDO, ANA M.G. ; KINOSHITA, ANGELA; BAFFA, OSWALDO. Pleistocene EQUUS (Equidae: Mammalia) from Northern Brazil: evidence of scavenger behavior by ursids on south american horses. Ameghiniana, v. 55, n. 5, p. 517-530, 2018. DOI: 10.5710/AMGH.05.07.2018.3069

    Abstract: During paleontological surveys conducted in 2013 and 2014 in Quaternary deposits from the Gruta do Urso cave, Tocantins State, nine isolated teeth and five postcranial elements of Equus neogeus were recovered. Absolute datings indicate that E. neogeus inhabited the surroundings of Gruta do Urso cave during the Last Glacial Maximum. The specimens probably represent very young individuals that died outside the cave, were weathered prior to the final burial, with ontogenetic and taphonomic similarities. Herein, we report the first scavenger interaction of ursids and equids in the South American fossil record.

    Icon

  • IPEN-DOC 25617

    SILVA, J.; ELIAS, M.; LIMA, N. ; CANEVAROLO, S.. Morphology in multilayer blown films of polypropylene and ethylene-octene copolymer blends. International Polymer Processing, v. 33, n. 3, p. 345-354, 2018. DOI: 10.3139/217.3526

    Abstract: In this work the microstructure of multilayer blown films consisting of a core layer placed between two external ones is studied. The core layer is a blend with 70% (w/w) of a homopolypropylene PP and 30% of a metallocene-catalyzed ethylene- octene copolymer mEOC (LLDPE or VLDPE), whereas the external symmetrical layers are composed of LLDPE or they have the same composition as the core layer. The PP and PE crystalline phases formed during the film blowing were investigated by thermal analysis, mechanical properties, TEM morphology and X-ray diffraction pole figures. These films successfully combine the high mechanical strength of PP with the quasi-isotropic behavior of blown PE. Multilayer film containing PP/mEOC blends, particularly blends of PP70/LLDPE30, show better balanced tensile properties when compared at crossed directions. The presence of VLDPE in the blends shifts downwards the melting and crystallization temperatures and crystallinity of PP. X-Ray pole figures suggest the occurrence of epitaxial crystallization of the PE phase upon the PP crystals in these PP/mEOC blend films.

    Icon

  • IPEN-DOC 24809

    ANTONIO, PATRICIA L. ; OLIVEIRA, RAQUEL A.P.; KHOURY, HELEN J.; CALDAS, LINDA V.E. . Evaluation of the thermally and optically stimulated response of an Italian Obsidian irradiated in 60Co beams. Radiation Physics and Chemistry, v. 155, SI, p. 115-120, 2019. DOI: 10.1016/j.radphyschem.2018.06.034

    Abstract: From Obsidian silicate, in its natural form, pellets were manufactured adding Teflon to the material in powder. These pellets were exposed to the gamma radiation beams of a 60Co source in a dose interval from 10 Gy to 10 kGy. The Obsidian in powder was investigated in relation to its physical and chemical characteristics, by means of the X-ray diffraction, scanning electronic microscopy and energy-dispersive X-ray spectroscopy techniques. After the irradiation procedure, the signal of the samples was evaluated by means of three techniques: thermoluminescence (TL), optically stimulated luminescence (OSL) and thermally stimulated exoelectron emission (TSEE). The objective of this work was to verify the TL, OSL and TSEE response of the Obsidian+Teflon pellets after exposure to high doses of gamma radiation. Different response characterization tests were performed, as TL and TSEE emission curves, OSL signal decay, reproducibility, dose-response curves, lower detection limits and fading. From these results, it can be observed that the Obsidian+Teflon pellets present good conditions to be used as high dose gamma radiation detectors; the results obtained with the OSL technique were the most adequate in terms of response in function of absorbed dose. The fading of the signals, varying from about 26% (TSEE) to 44% (OSL), in a time interval of 360 h post-irradiation, also showed favorable results for the use of this material as radiation detector, when the measurements are taken after a defined time interval.

    Icon

  • IPEN-DOC 24801

    NASCIMENTO, ERIBERTO O. do; OLIVEIRA, LUCAS N. de ; CALDAS, LINDA V.E. . Improvement of Sievert Integration Model in brachytherapy via inverse problems and Artificial Neural Networks. Radiation Physics and Chemistry, v. 155, SI, p. 260-264, 2019. DOI: 10.1016/j.radphyschem.2018.05.024

    Abstract: Increasing the radial distance, the accuracy of the Sievert Integration Model (SIM) decreases in a nonlinear manner, adding errors up of 10% into the dose rate calculations; a similar fact occurs to the 2D anisotropy function where the errors may achieve 30% as already was related. For that reason, this paper sought an innovative approach to optimize the error variance and its biases of dose rate calculations around a Nucletron brachytherapy source of 192Ir from 0 to 10 cm taken in the radial distance, using an improved SIM through a hybrid coupling of Artificial Neural Networks (ANNs) and Inverse Problem Theory (IPT). Since the traditional approach relies into the use of a small data set of dose rate, the ANNs generalized these doses, making possible to search more broadly optimum parameters to SIM using the IPT. The results showed excellent accuracy evaluated with the Root Mean Square Percentage Error (RMSPE). In conclusion, the low RMSPE values indicate that the methodology is consistent, showing an excellent agreement with the state of art of dosimetric measurement techniques.

    Icon

  • IPEN-DOC 24788

    PERINI, ANA P. ; SANTOS, WILLIAM S.; NEVES, LUCIO P.; BELINATO, WALMIR; CALDAS, LINDA V.E. . Estimation of conversion coefficients for absorbed and effective doses for pediatric CT examinations in two different PET/CT scanners. Radiation Physics and Chemistry, v. 155, SI, p. 9-16, 2019. DOI: 10.1016/j.radphyschem.2018.07.009

    Abstract: Normally, during medical procedures, special attention must be given to pediatric patients when compared to adults. This is specially relevant during procedures involving ionizing radiation, as CT scans, given that children are considerably more sensitive to radiation induced stochastic effects than adults. In order to investigate the radiation doses on radiosensitive organs of pediatric patients, undergoing head, chest and abdomen CT procedures, numerical dosimetry was employed in this work. The novelty is the use of a new set of pediatric virtual anthropomorphic phantoms, coupled with Monte Carlo simulation, to determine the conversion coefficients for absorbed and effective doses. Two CT equipment were simulated, taking into account the main characteristics of those commercially available. The results were converted to conversion coefficients (mGy/100 mA) for several organs and tissues, and the highest values were obtained for the newborn phantom. This numerical approach employed a new and reliable technique for pediatric CT dosimetry.

    Icon

  • IPEN-DOC 24780

    ROCHA, F.D.G. ; VILLANI, D. ; CAMPOS, V.P. ; NOGUEIRA, M.S.; GOULART, M.E.; SICHITO, V.A.; CAMPOS, L.L. . Performance of TL and OSL techniques using CaSO4 and Al2O3 dosimeters for mean glandular dose (MGD) and entrance surface skin dose (ESD) determination in a digital mammographic unit as alternative dosimeters. Radiation Physics and Chemistry, v. 155, SI, p. 48-52, 2019. DOI: 10.1016/j.radphyschem.2018.06.037

    Abstract: The mammography is the most important and simple tool in the diagnosis of breast diseases in women. In digital mammography, the process of image acquisition, display and storage are separated which allows optimization of each. Despite the innumerous advantages of this technique, such as an accurate diagnosis for women with dense breast, it was noticed an increase of radiation doses to obtain the images by this system. As with any examination that includes x-rays, there is always a small stochastic risk of inducing cancer, it is therefore important to evaluate the risk from the dose delivered to the patient during the screening process. The mean glandular dose within the breast is the recommended quantity to evaluate the risk from radiation to the breast. To guarantee proper conditions of protection for patients, the radiation dose should be as low as reasonably achievable possible and simultaneously compatible with image quality requirements. Thus, this work proposes the use of the thermoluminescent (TL) CaSO4:Dy sintered discs, produced at IPEN, widely used in individual, environmental and area monitoring in Brazil, and Al2O3:C optically stimulated luminescence (OSL) ‘dot’ dosimeters, manufactured by Landauer® Inc., as application as easy-to-use and low cost alternative dosimeters to evaluate the entrance skin doses (ESD) delivered to patients, the half value layer (HVL) and the mean glandular doses (MGD) in a mammographic digital unit, comparing these two techniques with the results obtained using an Allin- one QC meter. The results obtained demonstrated that the TL and OSL dosimetry systems and the CaSO4 and Al2O3 dosimeters used are able to evaluate the entrance skin dose as well as mean glandular doses in a digital mammographic unit accurately within the requirements, and they can be considered a practical, simple, easy-touse and low cost tools for verification of these items in a Quality Assurance Program.

    Icon

  • IPEN-DOC 24752

    SOARES, MARIA R. ; SANTOS, WILLIAM S.; NEVES, LUCIO P.; PERINI, ANA P. ; BATISTA, WILSON O.G.; BELINATO, WALMIR; MAIA, ANA F.; CALDAS, LINDA V.E. . Dose estimate for cone beam CT equipment protocols using Monte Carlo simulation in computational adult anthropomorphic phantoms. Radiation Physics and Chemistry, v. 155, SI, p. 252-259, 2019. DOI: 10.1016/j.radphyschem.2018.06.038

    Abstract: Cone beam computed tomography (CBCT) has become essential for dental diagnoses in the last decade. This is supported by its low cost and low doses, when compared to medical CT. Following this increase in CBCT procedures, it is necessary to ensure the image quality within low radiation doses to the patients. This is an especially difficult challenge in CBCT, given the number of equipment models (more than 50), radiographic techniques that may be employed, and technical information not available to the users by the manufacturers. The objective of this study was to estimate the cancer risk, effective and absorbed doses in tissues and organs for CBCT protocols intended for dental use. Monte Carlo (MC) simulations were used to estimate these quantities in tissues and organs with radiological importance, as those suggested by the International Commission of Radiological Protection (ICPR) report ICRP 103. Five different fields of view (FOV) were simulated to i-Cat Classic CBCT, using the MCNPX code. The virtual anthropomorphic phantoms FASH3 (Female Adult MeSH) and MASH3 (Male Adult MeSH) were also used. The effective dose estimative was in the range 75.15–142.20 μSv. The largest contribution to the effective dose was from the salivary glands (17%), thyroid (27%) and remainder tissues (28%). The results of this work showed that the effective and absorbed doses in tissues/organs vary according to the FOV, exposure parameters, and the positioning of the beam, relative to the radiosensitive organs. Furthermore, for the same exposure conditions, women can exceed the total risk of cancer by 26–34%, when compared to men.

    Icon

  • IPEN-DOC 24708

    BARRERA, G.R.; SOUZA, L.F.; NOVAIS, A.L.F.; CALDAS, L.V.E. ; ABREU, C.M.; MACHADO, R.; SUSSUCHI, E.M.; SOUZA, D.N.. Thermoluminescence and optically stimulated luminescence of PbO–H3BO3 and PbO–H3BO3–Al2O3 glasses. Radiation Physics and Chemistry, v. 155, SI, p. 150-157, 2019. DOI: 10.1016/j.radphyschem.2018.02.005

    Abstract: In the present work some dosimetric and structural properties of the lead borate glass (4.5PbO-1.9H3BO3) and lead aluminum borate glass (11.1PbO-2.9H3BO3-0.2Al2O3) were investigated. The glass samples were produced by fusion and fast cooling method. The dosimetric characterization was performed via thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. For this characterization, the samples were irradiated with a beta source (90Sr/90Y). TL emission curves, kinetic parameters, OSL decay curves, dose response curves, and the correlation between TL and OSL results were obtained. X-ray diffractometry (XRD) and infrared spectroscopy (FT-IR) of the samples were also performed. The XRD analyses confirmed the amorphous nature of the investigated glasses and the FT-IR analyses showed the different borate groups in their compositions. The TL emission curves of the glasses are composed by three peaks, located at different temperatures. The dose response curve in both TL and OSL analyses indicated linearity for most of the dose range studied. The OSL decay curves exhibited two components with different decay times.

    Icon

  • IPEN-DOC 25614

    SALES, T.N.S.; BOSCH-SANTOS, B. ; SAIKI, M. ; BURIMOVA, A. ; PEREIRA, L.F.D. ; SAXENA, R.N. ; CARBONARI, A.W. . Low temperature synthesis of pure and Fe-doped HfSiO4: Determination of Si and Fe fractions by neutron activation analysis. Radiation Physics and Chemistry, v. 155, SI, p. 287-290, 2019. DOI: 10.1016/j.radphyschem.2018.06.040

    Abstract: A new method of synthesis of hafnium silicate HfSiO4 (also known as hafnon) is reported. We observed a selfcontrolled incorporation of SiO2 from the quartz tube in which a sample of hafnium oxide nanoparticles was heated. This approach was then adapted to Fe-doped hafnon production. Sample structure, morphology and composition were characterized by X-ray diffraction, electron microscopy and neutron activation analysis. Diffraction data has shown that lattice parameters of doped HfSiO4 thus obtained are very close to those previously known for bare hafnon. The hafnon-like phase stabilized at T=900 °C which is about 500 °C lower than the corresponding transition of bare bulk hafnium silicate. The fractions of Si and Fe in the composite matrices were determined with neutron activation analysis. These results completed by X-ray diffraction data allowed to assume that (i) Fe initially substituted Hf in the HfO2 lattice; (ii) there was no migration of iron atoms from Hf to Si sites at the formation of hafnon-like phase; (iii) doped and undoped hafnium oxide has taken as much Si from the quartz as was needed for the arrangement of Fe1-xHfxSiO4 tetragonal system, 0≤x<0.2. Our results are consistent with those obtained for similar materials, such as metal (Fe,V) doped zircon, where the dopant also demonstrated catalytic effect on phase stabilization.

    Icon

  • IPEN-DOC 25596

    ARTHUR, PAULA B. ; VILLAVICENCIO, ANNA L. ; MACHI, ANDRÉ R. ; ROSSI, RODRIGO S. ; ARTHUR, VALTER . Control of Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae) by gamma radiation. Australian Journal of Basic and Applied Sciences, v. 12, n. 7, p. 85-88, 2018. DOI: 10.22587/ajbas.2018.12.7.14

    Abstract: The aim of the experiment was to determine the sterilizing dose from ionizing radiation by cobalt-60 to Alphitobius diaperinus (Panzer, 1797)(Coleoptera: Tenebrionidae) in peanuts. The study was conducted in the laboratory of Radiobiology and Environment of the Center for Nuclear Energy in Agriculture - CENA / USP at Piracicaba, SP - Brazil. Peanuts samples infested with adults of A. diaperinus with 8 treatments and 5 repetitions were used. Each repetition consisted of 20 adults, a total of 100 individuals per treatment. The samples were irradiated in doses of 0 (control), 25, 50, 75, 100, 125, 150 and 175 Gy, in a source of cobalt-60, Gammacell-220 type, with a rate dose of 381Gy / h. The experiment was conducted in a room with a relative of 25 ± 5 ° C temperatures and humidity of 70 ± 5%. After 50 days of irradiation process was evaluated of the number of emerged insects in each treatment. The results show that the sterilizing doses in F1 and F2 generations respectively were: 150 Gy and 125 Gy. The dose of 150 Gy of gamma radiation can be used in both generations as phytosanitary treatment to control of A. diaperinus infested peanuts.

    Icon

  • IPEN-DOC 25595

    FRANCO, JOSÉ G. ; FRANCO, SUELY S.H.; FRANCO, CAIO H.; FRANCO, LUISA H.; FRANCO, MARIA A.H.; ARTHUR, PAULA B. ; VILLAVICENCIO, ANNA L.C. ; ARTHUR, VALTER . Low doses of Gamma Radiation in Soybean. Australian Journal of Basic and Applied Sciences, v. 12, n. 9, p. 78-80, 2018. DOI: 10.22587/ajbas.2018.12.9.13

    Abstract: The degree of radio sensitivity depends mainly on the species, the stage of the embryo in the irradiation, the doses used and the criteria used to measure the effect. One of the most common criteria for evaluating seed radio sensitivity is to measure the plant's average yield. The dried soybean seeds were exposed to low doses of gamma radiation from Cobalt-60, Gammacell-220 type source, at a dose rate of 0.245 kGy. In the first stage the objective was to study the effects of radiation stimulation on germination, growth and plant production. Four doses of radiation were applied as follows: 0 (control); 25; 50; 75 and 100 Gy. Seed germination harvested seed number and total yield were evaluated to identify the occurrence of stimulation. The low doses of gamma radiation in the seeds that stimulate the production were doses of 25, 50 and 75 Gy. In the second stage the objective was also to study the effects of radiation stimulation on germination, growth and plant production. In this case, a treatment with three doses of radiation was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination harvested seed number and total yield were evaluated to identify the occurrence of stimulation. The number of soybean seeds and plants were handled following the standard seed production in Brazil. There is evidence in the results showing that the use of low doses of gamma radiation can stimulate the germination and the production of plants.

    Icon

  • IPEN-DOC 25585

    SILVA, JEFFERSON de J. ; MASSICANO, ADRIANA V.F. ; ALCARDE, LAIS F. ; BENEDETTO, RAQUEL ; BOAS, CRISTIAN A.W.V. ; DIAS, LUIS A.P. ; MENGATTI, JAIR ; ARAUJO, ELAINE B. de . Avaliação pré-clínica do potencial de inibidor do antígeno de membrana prostático específico (PSMA) radiomarcado com lutécio-177 no tratamento do câncer de próstata. Revista Brasileira de Farmácia, v. 99, n. 3, p. 2861-2876, 2018.

    Abstract: Diversos radiofármacos PSMA-específicos têm sido apresentados como proposta para o diagnóstico do câncer de próstata, bem como para o tratamento de pacientes com câncer metastático resistente à castração e às terapias convencionais. Este trabalho estudou a marcação e estabilidade radioquímica do inibidor do receptor PSMA, Glu-NH-CO-NH-Lys(Ahx)-DOTA com 177Lu (PSMA-DOTA-177Lu), e realizou estudos pré-clínicos para avaliar seu potencial para a terapia do câncer de próstata. O radiofármaco foi obtido com pureza radioquímica elevada (PR > 95%) em todas as condições de marcações estudadas e permaneceu estável quando armazenado sob congelamento por até 48 horas, mesmo com atividade específica alta (74 MBq/μg). O ensaio de ligação específica do PSMA-DOTA-177Lu mostrou fração significativa de ligação às células LNCaP de tumor de próstata, exclusivamente à superfície celular. Os parâmetros farmacocinéticos determinados no estudo in vivo em camundongos BALB/c são compatíveis com o rápido clareamento sanguíneo e excreção renal. O radiofármaco demonstrou alta estabilidade em soro humano in vivo por um período de até 24 horas, que foi confirmada pela baixa captação óssea demonstrada nos estudos in vivo de biodistribuição. Os resultados favoráveis deste estudo sugerem a realização de ensaio clínico controlado deste novo radiofármaco para avaliar seu potencial no tratamento do câncer de próstata.

    Icon

  • IPEN-DOC 25584

    ROSSETTI, DILCE R.; GRIBEL, ROGERIO; TOLEDO, PETER M.; TATUMI, SONIA H.; YEE, MARCIO; TUDELA, DIEGO R.G.; MUNITA, CASIMIRO S. ; COELHO, LUIZ de S.. Unfolding long-term Late Pleistocene–Holocene disturbances of forest communities in the southwestern Amazonian lowlands. Ecosphere, v. 9, n. 10, p. e02457-1 - e02457-32, 2018. DOI: 10.1002/ecs2.2457

    Abstract: Linking the distribution of plant species to geology has generally been biased by the oversimplification of landscape evolution and the lack of understanding of complex geological processes. The Amazonian lowlands have forests in different successional stages, and a growing perception is that such heterogeneity results from long-term environmental changes. This hypothesis is investigated by designing an analytical model based on past and present-day vegetation and successions of the plant communities, combined with an advanced understanding of geological history. An area of southwestern Amazonia was selected for floristic inventories, and we interpreted the paleovegetation based on C/N and d13C analyses of sedimentary organic matter. These data were examined in the context of the geological evolution on the basis of new sedimentological and chronological data. The topographically high Late Pleistocene deposits had continuous and highly diversified late-successional terra firme forests as well as local fluvial paleolandforms of younger ages with less diversified campinarana forests. Late Pleistocene–Holocene terrains in intermediate elevations had terra firme forests, but shorter trees with lower basal areas and ecotonal forests appeared near the confines of the forest–savanna, while Holocene deposits recorded only seasonally flooded varzea forests. Several deposits of Late Pleistocene and Late Pleistocene–Holocene age recorded an expansion of C4 terrestrial plants before the establishment of the forest from ~20,000 cal yr BP to 7578 cal yr BP, which is not related to past arid episodes. We recorded forests with onsets at 6130–3533 cal yr BP, 3402–2800 cal yr BP, and 1624–964 cal yr BP to terra firme, varzea, and ecotonal forests, respectively. However, not all forests have reached maturity stages due to their location on terrains with a diverse history of terrace downcutting and deposition, which had a direct impact on local hydrology with the interaction of topographic gradients. The hydrology of the study area was also controlled by the distance from the main river valley. Capturing long-term disturbances over this region of still pristine forests may help elucidate the potential mechanisms that also determine trends in tree growth and forest diversity in other Neotropical regions.

    Icon

  • IPEN-DOC 25583

    MUNITA, CASIMIRO S. ; CARVALHO, PATRICIA R. ; OLIVEIRA, CLAUDIA A. de; AMARAL, ALENCAR de M.; SULLASI, HENRY L.. Estudo da mobilidade logística a partir da caracterização química da cerâmica do “Sítio Capim” em Araripina, Pernambuco, Brasil / Study of logistic mobility from the chemical characterization of “Capim Site” ceramics in Araripina, Pernambuco, Brazil. Cadernos do Lepaarq, v. 15, n. 30, p. 179-190, 2018.

    Abstract: Neste trabalho de cunho interdisciplinar foi utilizado método de análise por ativação com nêutrons instrumental (INAA) com o objetivo de determinar a composição química elementar de 57 fragmentos de cerâmica proveniente de cinco manchas do sítio arqueológico “Sítio Capim”, no estado de Pernambuco, no Brasil. O conjunto de dados foi analisado por meio de análise de cluster e análise discriminante para a definição de grupos químicos. Os resultados mostraram três grupos químicos distintos, as diferenças podem ser entendidas em termos de mobilidade desses grupos humanos devido à disponibilidade de matérias-primas.

    Icon

  • IPEN-DOC 25563

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O. do; ANDREETA, MARCELLO R.B.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Characterization of lithium diborate, sodium diborate and commercial sodalime glass exposed to gamma radiation via linearity analyses. Radiation Physics and Chemistry, v. 155, SI, p. 133-137, 2019. DOI: 10.1016/j.radphyschem.2018.06.031

    Abstract: The linearity characteristic in radiation dosimetry presents a growing interest. Glasses have been applied to high radiation doses. In this work, materials will be analyzed and compared in relation to their linearity ranges. Lithium diborate, sodium diborate and commercial glass were irradiated with doses from 10 Gy to 10 kGy using a 60Co Gamma-Cell system 220 and evaluated with the UV–vis technique. The sensitivity analyses were applied through four methodologies, searching for linear regions in their response. The results show that all four applied analyses indicate linear regions for the tested radiation detectors. The materials with higher linearity range, in descending order, were lithium diborate, sodium diborate and commercial soda-lime glass. The radiation detectors present potential use for radiation dosimetry in intermediate and high doses.

    Icon

  • IPEN-DOC 25107

    KUAHARA, L.T. ; CORREA, E.L. ; CARNEIRO, R.C.G. ; BEZERRA, R.R.L. ; POTIENS, M.P.A. . Influence of the vials radioactive residue in Nuclear Medicine procedure applied to a new “in situ” activimeter calibration methodology. Radiation Physics and Chemistry, v. 155, SI, p. 291-293, 2019. DOI: 10.1016/j.radphyschem.2018.06.021

    Abstract: In this study we present a new “in situ” calibration methodology establishment for activimeters – i.e., this equipment calibration can be made at the hospital and/or the nuclear medicine service (NMS) – and also the importance of considering vials radioactive residue when generating the calibration coefficient in terms of activity (NA). For the calibration, two methods are presented here: in the first, 99mTc sample activity (AC) is measured in the NMS. Then it is sent to the Instruments Calibration Laboratory (LCI/IPEN) where the reference activity (AR) is obtained under controlled conditions in a reference vial. After geometry and residue corrections, NA is calculated. In the second method, AR is obtained at the LCI, then 99mTc sample is sent to the hospital/NMS, where AC is measured and NA calculated. Calibration methodologies were applied to three NMS and to four equipment belonging to the radiopharmaceutical production facility (CR) at the Nuclear and Energy Research Institute (IPEN). Both methodologies were tested with and without residual activity corrections under controlled conditions. Variations of up to 4% were obtained.

    Icon

  • IPEN-DOC 25559

    SERRA, EDIOMAR C.; BRANDIM, AYRTON de S.; SANTOS, DIEGO M. dos; CORREA, OLANDIR V. ; RAMANATHAN, LAUGUDI V. ; SALGADO, MARIA de F.. Oxidação do aço inoxidável ABNT 5601 - grau 409 em altas temperaturas em atmosfera de argônio / Oxidation ABNT 5601 degree 409 ferritic stainless steel at high temperature in argon atmosphere. Tecnologia em Metalurgia, Materiais e Mineração, v. 15, n. 1, p. 2-7, 2018. DOI: 10.4322/2176-1523.1146

    Abstract: Aços inoxidáveis são ligas ferrosas resistentes à corrosão, devido seu alto teor de cromo. São utilizadas em ambientes com gases agressivos em altas temperaturas especialmente na indústria e aplicações tecnológicas. O objetivo desta pesquisa é investigar a cinética de crescimento e a composição de filmes do óxido formados sobre o aço ABNT 5601 - grau 409 entre as temperaturas 850 °C e 950 °C, na atmosfera de argônio, contendo 1ppm de O2. As amostras foram oxidadas em uma termobalança, com sensibilidade de ± 1 μg, por 43,4 horas de exposição. A cinética de crescimento dos filmes de óxidos foi estabelecida medindo-se o ganho de massa por unidade de área versus tempo de oxidação seguindo uma lei parabólica. A microestrutura e a composição química dos óxidos foram analisadas por microscopia eletrônica de varredura, espectroscopia dispersiva de energia. Análises químicas descrevem que os filmes formados sobre o aço ABNT 5601 - grau 409 nas diferentes temperaturas em argônio contêm o cromo como elemento majoritário além do Mn, Fe, Ti. Ao se comparar as taxas de oxidação, nas diferentes temperaturas, entre 850 e 950 °C observa-se que o aço apresenta maior taxa de oxidação a 850 °C e menor a 950 ºC.

    Icon

  • IPEN-DOC 25522

    VIEIRA, D.P. ; GALISTEO JUNIOR, A.J.; ANDRADE JUNIOR, H.F. de. Inhibition of nitric oxide synthase activity and chemokine (CXCL12) supplementation can improve hematopoietic reconstitution in mice lethally irradiated by 60Co gamma radiation. Brazilian Journal of Radiation Sciences, v. 07, n. 01, p. 1-24, 2019. DOI: 10.15392/bjrs.v7i1.789

    Abstract: Reduction of nitric oxide (NO) production is related to increased survival in some models of infection and ionizing radiation (IR) exposure. The work used lethally irradiated (60Co, 8Gy) C57Bl6j mice, treated or not with aminoguanidine (AG), an inhibitor of an isoform of nitric oxide synthase (iNOS). Also tested iNOS-/- knockout mice and a distinct group treated intraperitoneally with synthetic CXCL12, a homing chemokine related to hematopoietic reconstitution after IR exposures. Aminoguanidine treatment lead to an overshoot of proliferation of hematopoietic CD34+ cells in bone marrows (day 2 after IR) and spleens (days 2 and 4 after IR) of irradiated mice, showing a compensative response of these organs against deleterious effects of radiation. CXCL12 mRNA production was increased on spleens of AG-treated mice at day 2 after IR, but not on other periods neither in bone marrows. CXCL12 administration did not alter CD34+ counts but seemed to keep circulating platelet counts in levels comparable to controls. Thus, CXCL12 and AG administration could help on bone marrow repopulation after critically exposed individuals.

    Icon

  • IPEN-DOC 25547

    RODRIGUES, LUCIANA A.S.; MEIRELES, GEORGE C.X.; RODRIGUES, LETICIA L.C. ; GALON, MICHELI Z.; FAVARATO, DESIDERIO; KREIMER, SERGIO; MARCHIORI, GILBERTO G.A.; LIMA, ADRIANA C. de. Comparação da exposição radiológica de pacientes submetidos à coronariografia e à intervenção coronária percutânea estadiada ou ad hoc pelo acesso radial / Comparison of radiological exposure of patients undergoing coronary angiography and staged or ad hoc percutaneous coronary intervention by radial access. Journal of Transcatheter Interventions, v. 27, n. eA201814, p. 1-7, 2019. DOI: 10.31160/JOTCI201927A201814

    Abstract: Introdução: A intervenção coronária percutânea ad hoc pelo acesso radial tem se tornado frequente nos serviços de cardiologia intervencionista, com redução das taxas de sangramento, complicações vasculares e diminuição dos custos. São escassas, na literatura médica, informações sobre as taxas de exposição radiológica (produto kerma área − Pka − e kerma incidente no ar − Kai), nesses procedimentos por tal via. O objetivo do estudo foi comparar as variáveis radiológicas das intervenções coronárias percutâneas estadiadas com as intervenções ad hoc pelo acesso radial. Métodos: Foram estudados 120 pacientes, divididos em dois grupos de 60 cada, submetidos à coronariografia diagnóstica e intervenção coronária percutânea estadiada (Grupo A) vs. ad hoc (Grupo B), pelo acesso radial, no período de agosto de 2014 a setembro de 2015. Foram mensurados os valores das taxas radiológicas. Resultados: Quando comparados os Grupos A e B, observamos índice de massa corporal de 27,83±4,20kg/m2 vs. 26,88±4,14kg/m2 (p=0,3); Pka total de 16.222,5±10.613,5μGym2 vs. 12.029,2±7.360,6μGym2 (p=0,01); Kai total de 3.886,8±2.946,7mGy vs. 2.940,3±1.841,0mGy (p=0,04); tempo de escopia total de 23,2±13,17 minutos vs. 17,1±9,68 minutos (p=0,0009), escore SYNTAX de 14,7±8,3 vs. 13,7±8,9 (p=0,54). Conclusão: As taxas radiológicas das intervenções coronárias percutâneas ad hoc foram menores do que nas estadiadas pelo acesso radial.

    Icon

  • IPEN-DOC 25536

    ARAUJO, JOAO V. de S. ; XAVIER, MARIANA M. ; MACHADO, CARULINE S.C.; QUEIROZ, FERNANDA M.; COSTA, ISOLDA . Estudo da influência dos tratamentos termomecânicos T8 e T851 na microestrutura e na resistência à corrosão da liga AA2198. Revista Corrosão & Proteção, v. 15, n. 63, p. 32-44, 2018.

    Abstract: Ligas de Al-Cu-Li têm mostrado grandes vantagens em relação às convencionais ligas de Al-Cu usadas na indústria aeroespacial, devido as boas propriedades mecânicas e baixa densidade. As propriedades mecânicas destas ligas dependem de sua microestrutura e esta por sua vez dos tratamentos termomecânicos na qual as ligas são submetidas durante o processo de fabricação. Neste estudo os efeitos de dois tratamentos termomecânicos, T8 e T851, na resistência a corrosão da liga AA2198 foram comparados. O principal precipitado endurecedor destas ligas, a fase T1 (Al2CuLi), foi analisada por microscopia eletrônica de transmissão (TEM). Os resultados de microestrutura, microdureza e calorimetria diferencial de varredura (DSC) mostraram diferenças para as ligas com os dois tratamentos. A liga submetida ao tratamento T851 mostrou maior densidade de fase T1. Além disso, a caracterização microestrutural revelou grãos alongados para o tratamento T8 e grãos equaxiais para tratamento T851. Estes resultados foram comparados com os do ensaio de imersão e de visualização em gel.

    Icon

  • IPEN-DOC 25535

    KLUMPP, RAFAEL E. ; SILVA, REJANE M.P. da; DONATUS, UYIME ; MACHADO, CARULINE de S.C. ; AYUSSO, VICTOR H. ; MILAGRE, MARIANA X. ; ARAUJO, JOAO V. de S. ; COSTA, ISOLDA . Influência da composição da solução de tratamento de superfície na resistência à corrosão da liga AA2024-T3. Tratamento de Superfície, n. 212, p. 23-28, 2019.

    Abstract: Os tratamentos de superfície de ligas de alumínio em soluções contendo íons de terras raras têm se mostrado promissores para a substituição dos tratamentos que utilizam íons de cromo hexavalente em sua composição. A composição das soluções de tratamento com terras raras é um fator importante na propriedade de proteção à corrosão da camada superficial formada. Neste trabalho, o efeito da adição de peróxido de hidrogênio à solução de tratamento para proteção à corrosão da liga AA2024-T3 foi investigado por técnicas eletroquímicas e microscópicas. Os resultados mostraram que a adição do peróxido de hidrogênio altera a morfologia da camada, o mecanismo de formação desta e resulta em propriedades de proteção levemente inferiores às da camada formada na ausência de peróxido.

    Icon

  • IPEN-DOC 25266

    TRINDADE, M.A.; CAMPOS, M.F. de; LANDGRAF, F.J.G.; LIMA, N.B. ; ALMEIDA, A.. Influence of thickness on magnetic and microstructural properties in electrical steels semi-processed of low efficiency. Materials Science Forum, v. 930, p. 466-471, 2018. DOI: 10.4028/www.scientific.net/MSF.930.466

    Abstract: In this study, a steel for semiprocessed electrical purposes of non-oriented grain with approximately 0.05% carbon content and 0.02% silicon content was evaluated. Lamellas with kind of thicknesses 0.58 mm, 0,66 mm and 0.87 mm were processed on an industrial scale with a strain rate in the hardening lamination between 3 and 5%. The magnetic properties were evaluated after the wet heat treatment. The loss separation method was applied, estimating the hysteretic plot with hysteresis measure in the quasi static condition and the parasitic losses calculated according to Thomson's Equation. By increasing grain size, permeability increases and coercivity decreases. However, in the case of losses, there is an optimum grain size. After the procedure of separation of losses, it was observed that increase of thickness results in increase of the anomalous parcel of magnetic losses.

    Icon

  • IPEN-DOC 25261

    GALIZONI, BRENO B.; COUTO, ANTONIO A. ; REIS, DANIELI A.P.. Heat treatments effects on nickel-based superalloy inconel 713C. Metals, v. 9, n. 47, 2019. DOI: 10.3390/met9010047

    Abstract: The purpose of this work is to study the effect of heat treatments on the microstructure of the nickel-based superalloy Inconel 713C. Three different conditions were studied and the results compared: (1) as cast; (2) solid solution treatment (1179 C/2 h) and (3) stabilization heat treatment (1179 C/2 h plus 926 C/16 h). Inconel 713C is normally used in the as-cast condition, an improvement in the 980 C stress-rupture life is often obtained by a solution heat treatment. However, the material in this condition tested under high stress at 730 C shows a marked decreased in rupture life and ductility. The mechanical resistance in creep increases in Inconel 713C by precipitation hardening phase, with ’ (Ni3Al) formed during the heat treatments. The characterization techniques used were: chemical analysis, hardness testing, X-ray diffraction, optical microscopy and scanning electron microscopy (SEM), EDS analyzes and thermocalculation. The SEM and EDS analysis illustrated the , ’ and carbides. The matrix phase ( ), has in its constitution the precipitation of the ’ phase, in a cubic form, and in some regions, carbides were modified through the heat treatments. (M23C6-type) and boride (M3B2 type) identified with the use of the thermocalculation. The heat treatments increase the relative intensity of niobium in the carbides. The hardness test was not achieved because the material was overaged.

    Icon

  • IPEN-DOC 25259

    FAUSTINO, M.G. ; LANGE, C.N. ; MONTEIRO, L.R. ; FURUSAWA, H.A. ; MARQUES, J.R. ; STELLATO, T.B. ; SOARES, S.M.V. ; SILVA, T.B.S.C. da ; SILVA, D.B. da ; COTRIM, M.E.B. ; PIRES, M.A.F. . Top down arsenic uncertainty measurement in water and sediments from Guarapiranga dam (Brazil). Journal of Physics: Conference Series, v. 975, p. 1-6, 2018. DOI: 10.1088/1742-6596/975/1/012024

    Abstract: Total arsenic measurements assessment regarding legal threshold demands more than average and standard deviation approach. In this way, analytical measurement uncertainty evaluation was conducted in order to comply with legal requirements and to allow the balance of arsenic in both water and sediment compartments. A top-down approach for measurement uncertainties was applied to evaluate arsenic concentrations in water and sediments from Guarapiranga dam (São Paulo, Brazil). Laboratory quality control and arsenic interlaboratory tests data were used in this approach to estimate the uncertainties associated with the methodology.

    Icon

  • IPEN-DOC 25257

    CABRAL, T.S.; SILVA, C.N.M. da; POTIENS, M.P.A. ; SOARES, C.M.A.; SILVEIRA, R.R.; KHOURY, H.; SAITO, V.; FERNANDES, E.; CARDOSO, W.F.; OLIVEIRA, H.P.S. de; PIRES, M.A.; AMORIM, A.S. de; BALTHAR, M.. Comparison for air kerma from radiation protection gamma-ray beams with brazilian network - 2016/2017. Journal of Physics: Conference Series, v. 975, p. 1-9, 2018. DOI: 10.1088/1742-6596/975/1/012042

    Abstract: The results of the comparison involving 9 laboratories in Brazil are reported. The measured quantity was the air kerma in 137Cs and 60Co, at the level of radioprotection. The comparison was conducted by the National Laboratory Metrology of Ionizing Radiation (LNMRI/IRD) from October 2016 to March 2017. The largest deviation between the calibration coefficients was 0.8% for 137Cs and 0.7% for 60Co. This proficiency exercise proved the technical capacity of the Brazilian calibration network in radiation monitors and the results were used by some in the implementation of the standard ISO/IEC 17025.

    Icon

  • IPEN-DOC 25217

    ZHU, LIYE; MARTIN, MARIA V.; GATTI, LUCIANA V. ; KAHN, RALPH; HECOBIAN, ARSINEH; FISCHER, EMILY V.. Development and implementation of a new biomass burning emissions injection height scheme (BBEIH v1.0) for the GEOS-Chem model (v9-01-01). Geoscientific Model Development, v. 11, n. 10, p. 4103-4116, 2018. DOI: 10.5194/gmd-11-4103-2018

    Abstract: Biomass burning is a significant source of trace gases and aerosols to the atmosphere, and the evolution of these species depends acutely on where they are injected into the atmosphere. GEOS-Chem is a chemical transport model driven by assimilated meteorological data that is used to probe a variety of scientific questions related to atmospheric composition, including the role of biomass burning. This paper presents the development and implementation of a new global biomass burning emissions injection scheme in the GEOS-Chem model. The new injection scheme is based on monthly gridded Multi-angle Imaging SpectroRadiometer (MISR) global plume-height stereoscopic observations in 2008. To provide specific examples of the impact of the model updates, we compare the output from simulations with and without the new MISR-based injection height scheme to several sets of observations from regions with active fires. Our comparisons with Arctic Research on the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) aircraft observations show that the updated injection height scheme can improve the ability of the model to simulate the vertical distribution of peroxyacetyl nitrate (PAN) and carbon monoxide (CO) over North American boreal regions in summer.We also compare a simulation for October 2010 and 2011 to vertical profiles of CO over the Amazon Basin. When coupled with larger emission factors for CO, a simulation that includes the new injection scheme also better matches selected observations in this region. Finally, the improved injection height improves the simulation of monthly mean surface CO over California during July 2008, a period with large fires.

    Icon

  • IPEN-DOC 25216

    SUTANTO, ERWIN; CHANDRA, FRANGKY; GONNELLI, EDUARDO ; SUHARININGSIH. Residual current measurement using helmholtz coil configuration with different current flow. International Journal of Electrical and Computer Engineering, v. 8, n. 3, p. 1432-1441, 2018. DOI: 10.11591/ijece.v8i3.pp1432-1441

    Abstract: For leakage current safety, Residual Current Device (RCD) has been well known. The purpose of this work is to make the employment of low price components to measure residual current feasible and the Residual Current Device (RCD) must to be taken into account because it is a well known device for leakage current safety. For this purpose, experiments employing the Helmholtz Coil Configuration were performed with the different current flow. Furthermore, the residual current was formulated and simulated through the software Easy Java Simulation (EJS). The results showed that it is possible to move the magnet into different angles using leakage current with linear gradient as low as 0.382 degree/mA. Finally, it was proposed a way to increase the sensitivity and to reduce the hysteresis phenomenon.

    Icon

  • IPEN-DOC 25215

    SILVA, MAYANE B.; HERREROS, MARIO M.A.G.; BORGES, FABRICIO Q. . O regime de comércio internacional: evoluções e impasses do GATT à OMC / The international trade regime: GATT and WTO evolutions and impasses. Relaciones Internacionales, v. 27, n. 54, p. 69-85, 2018. DOI: 10.24215/23142766e027

    Abstract: Este estudo objetiva analisar a evolução do regime multilateral de comércio internacional e problematiza os principais desafios contemporâneos responsáveis pela fragilização interna deste regime. A metodologia dividiu-se em três partes. Na primeira, realizou-se um esclarecimento dos conceitos basilares da temática. Em seguida, analisouse o processo evolutivo e as modificações no interior do regime de comércio internacional. E por fim, examinou-se o processo constitutivo da Organização Mundial do Comércio e os principais desafios na manutenção de um regime de comércio que contribua para o dinamismo multilateral das relações comerciais internacionais. Os resultados demonstram a necessidade de reformas na agenda da Organização Mundial de Comércio de modo a contemplar novos atores e as dinâmicas impostas pelas cadeias de valor globais face ao desafio de regulação paralela dos novos megablocos de integração regional.

    Icon

  • IPEN-DOC 25214

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Synthesis, processing, and electron paramagnetic resonance response of Y1.98Eu0.02O3 micro rods. International Journal of Modern Physics: Conference Series, v. 48, p. 1860112-1 - 1860112-8, 2018. DOI: 10.1142/S2010194518601126

    Abstract: Innovating dosimetric materials, which includes design and development of new dosimetric materials based on rare earth oxides, is challenging. Yttrium oxide (Y2O3) is one of the most important sesquioxides and presents crystal characteristics that enable doping with rare earth ions, making it a promising material for radiation dosimetry. This paper reports on the development and measurement of Electron Paramagnetic Resonance (EPR) signal response for Y1.98Eu0.02O3 micro rods that have undergone facile low-pressure hydrothermal synthesis and bio-prototyping. Assynthesized powders with narrow sub-micrometer particle size distribution with d50 of 584 nm exhibited a reactive surface, which led to the formation of stable aqueous suspensions by controlling the surface charge density of particles through alkaline pH adjustment. Ceramic samples with dense microstructure were formed by sintering at 1600 ºC for 4h at ambient atmosphere. Y1.98Eu0.02O3 micro rods were irradiated using a 60Co source with doses from 1 to 100 kGy, and EPR spectra were measured at room temperature in X-band microwave frequencies. Sintered samples exhibited linearity of the main EPR signal response from 10 Gy to 10 kGy. Supralinearity was observed for higher doses, which is possibly ascribed to formation of more defects. Using europium as a dopant enhanced the EPR signal of yttrium rods remarkably, due to 4f–4f transitions of the Eu3+ ion. These innovative findings make europium-doped yttrium oxide a promising material for radiation dosimetry.

    Icon

  • IPEN-DOC 25213

    PEREIRA, C.V. ; FONTES, E.H. ; NANDENHA, J. ; ASSUMPCAO, M.H.M.T.; NETO, A.O. . Electrocatalytic performance of PtSn/C-In2O3 center dot SnO2 nanoparticles prepared by sodium borohydride reduction process for ethanol oxidation in acidic and alkaline electrolytes. International Journal of Electrochemical Science, v. 13, n. 11, p. 10587-10600, 2018. DOI: 10.20964/2018.11.49

    Abstract: PtSn/C-In2O3.SnO2 electrocatalysts were prepared by the borohydride reduction method in the single step using H2PtCl6.6H2O and SnCl2.2H2O as metal sources, sodium borohydride as reducing agent and a physical mixture of 85% Vulcan Carbon XC72 and 15% In2O3.SnO2 (indium tin oxide – ITO) as support. PtSn/C-In2O3.SnO2 electrocatalysts were characterized by X–ray diffraction (XRD), energy dispersive analysis (EDX), transmission electron microscopy (TEM), cyclic voltammetry (CV), chronoamperommetry (CA) and polarization curves in alkaline and acidic electrolytes (single cell experiments). The diffractograms of PtSn/C-In2O3.SnO2 electrocatalysts showed peaks associated to the face-centered cubic (fcc) structure of platinum, peaks which could be identified as a cassiterite SnO2 phase or with Indium-doped SnO2 (ITO) used as supports. TEM micrographs showed metal nanoparticles with average nanoparticle size between 2.4 and 2.7 nm. Ethanol oxidation in acidic and alkaline electrolytes was investigated at room temperature, by chronoamperommetry (CA), where PtSn/C-In2O3.SnO2 (70:30) showed the highest activity among all electrocatalysts in study considering ethanol oxidation for acid electrolyte, while for alkaline electrolyte the highest activity was observed for PtSn/C-In2O3.SnO2 (50:50). Polarization curves at 100oC showed PtSn/C-In2O3.SnO2 (70:30) with superior performance for ethanol oxidation for acidic electrolyte and PtSn/C (70:30) for alkaline electrolyte, when compared to Pt/C for both electrolytes. The best performance obtained by PtSn/C-In2O3.SnO2 (70:30) in real conditions could be associated with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of PtSn alloy or a synergetic effect between PtSn and In2O3.

    Icon

  • IPEN-DOC 25212

    LUZ, H.N. da; SOUZA, F.A. ; MORALLES, M. ; CARLIN, N.; OLIVEIRA, R.A.N.; BREGANT, M.; SUAIDE, A.A.P.; CHUBACI, J.F.D.; MATSUOKA, M.; SILVA, T.F.; MORO, M.V.; RODRIGUES, C.L.; MUNHOZ, M.G.. Characterization of multilayer Thick-GEM geometries as 10B converters aiming thermal neutron detection. EPJ Web of Conferences, v. 174, p. 1-4, 2018. DOI: 10.1051/epjconf/201817401012

    Abstract: Boron-based thermal neutron detectors have recently regained some attention from the instrumentation community as a strong alternative to helium-3 detectors. From the existing concepts exploiting boron layers in position sensitive detectors, the Cascade [1] is the one that takes full advantage of the 2D capabilities of gaseous detectors, with the position resolution not limited by the architecture of the detector. In this work, a proposal for the Cascade detector, based on Thick-GEMs is presented, together with some preliminary studies of the suitable pitch that optimizes the neutron conversion efficiency, while keeping the collection efficiency intact. The characterization of Thick-GEM prototypes produced in Brazil with hole pitch from 0.75 to 3 mm shows that these devices already present a stable performance at low gains, also resulting in fair energy resolution, when cascaded with a standard KaptonTM 50 µm GEM. Results of the first attempts of boron film depositions with Ion Beam Assisted Deposition and characterization by Ion Beam Analysis are also presented.

    Icon

  • IPEN-DOC 25208

    KATTI, K.V.; KHOOBCHANDANI, M.; THIPE, V.C.; AL-YASIRI, A.Y.; KATTI, K.K.; LOYALKA, S.K.; SAKR, T.M.; LUGAO, A.B. . Prostate tumor therapy advances in nuclear medicine: green nanotechnology toward the design of tumor specific radioactive gold nanoparticles. Journal of Radioanalytical and Nuclear Chemistry, v. 318, n. 3, p. 1737-1747, 2018. DOI: 10.1007/s10967-018-6320-4

    Abstract: We report herein an innovative approach to prostate tumor therapy using tumor specific radioactive gold nanoparticles (198Au) functionalized with Mangiferin (MGF). Production and full characterization of MGF-198AuNPs are described. In vivo therapeutic efficacy of MGF-198AuNPs, through intratumoral delivery, in SCID mice bearing prostate tumor xenografts are described. Singular doses of the nano-radiopharmaceutical (MGF-198AuNPs) resulted in over 85% reduction of tumor volume as compared to untreated control groups. The excellent anti-tumor efficacy of MGF-198AuNPs are attributed to the retention of over 90% of the injected dose within tumors for long periods of time. The retention of MGF-198AuNPs is also rationalized in terms of the higher tumor metabolism of glucose which is present in the xanthanoid functionality of MGF. Limited/no lymphatic drainage of MGF-198AuNPs to various non-target organs is an attractive feature presenting realistic scope for the clinical translation of MGF-198AuNPs in for treating prostate cancers in human patients. The comparative analysis of MGF-198AuNPs with other radioactive gold nanoparticles, functionalized either with epigallocatechin gallate or the Gum Arabic, has revealed significantly superior tumoricidal characteristics of MGF-198AuNPs, thus corroborating the importance of the tumor-avid glucose motif of MGF. Oncological implications of MGF-198AuNPs as a new therapeutic agent for treating prostate and various solid tumors are presented.

    Icon

  • IPEN-DOC 25207

    HARAGUCHI, MARCIO I.; KIM, HAE Y.; CALVO, WILSON A.P. . Results of process equipment imaging by tomographic gamma scan. Chemical Engineering Transactions, v. 69, p. 649-654, 2018. DOI: 10.3303/CET1869109

    Abstract: Gamma scanning is a nuclear inspection technique widely used for troubleshooting industrial process equipments in refineries and petrochemicals. A radiation source and detector move vertically along the height of the vessel and the radiation readings are used to plot the graph of density profile. In recent years, many improvements have been added to this technique, but essentially the result of gamma scanning still consists of a 1-D density plot. Developed in 2012, the tomographic gamma scan uses image reconstruction techniques to show the result of gamma scan as a 2-D density distribution image. In this work, we present the current status of the technology and the results obtained by applying the technique to real operating process equipment. The results present images that match well with the 1-D density plots obtained by the conventional gamma scan and reveal process and operational problems that has never been visualized before with the traditional technique. The tomographic gamma scan can be immediately applied in practice with low financial investment.

    Icon

  • 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.

    Icon

  • IPEN-DOC 25210

    LEITE, VICTOR C.; SCHIRRU, ROBERTO; MATTAR NETO, MIGUEL . Particle swarm optimization applied to the nuclear fuel bundle spacer grid spring design. Nuclear Technology, p. 1-9, 2018. DOI: 10.1080/00295450.2018.1516056

    Abstract: One of the main roles of the nuclear fuel bundle spacer grid (SG) is to safely support the fuel rods (FRs) through springs and dimples. The SG design is an important matter for nuclear power plant operation when a damaged FR could release fission products. For this work, Particle Swarm Optimization (PSO) is applied to define the geometries of the springs and dimples existing in a SG. Other algorithms had been used to optimize these geometries but not PSO. This paper proposes a PSO variable model and its fitness function in order to define an optimized geometry for the spring and the dimple so that they can provide sufficient gripping forces and minimize stresses. The implemented PSO was able to generate geometries of springs and dimples with stresses minimized and with a specific required stiffness value. The results of these two characteristics are compared with other results in the literature. For further work, PSO will be used to optimize other important design characteristics of a SG: grid-to-rod fretting, coolant flow-induced vibration, and the function of mixing coolant.

    Icon

  • IPEN-DOC 25205

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . Economically feasible mobile nuclear power plant for merchant ships and remote clients. Nuclear Technology, p. 1-15, 2018. DOI: 10.1080/00295450.2018.1546067

    Abstract: Recent studies point to a reduction of atmospheric pollution using nuclear energy for merchant ships. This work examines the development of an economically competitive nuclear power solution for merchant ship propulsion. The solution also addresses the requirements of a wider market, like islands, offshore oil platforms, and remote cities. System engineering and analysis at various product breakdown levels also propose architectural options to improve competitiveness of nuclear power in mobile nuclear power plants (MNPPs). Analyses include market research on clients and technical considerations on nuclear energy costs. The results show that an enterprise that delivers electric power to remote clients and dedicates to management of all nuclear aspects seems to be the best organizational and technical choice. Besides, ships should be of modular type and the MNPPs should be easily detachable at sea. Only container ships and remote islands demand enough power to justify the use of nuclear power. Nuclear power has high probability to be economically competitive for large container ships, however, only if public policies impose levels of risks akin to other industries.

    Icon

  • IPEN-DOC 25204

    DUTRA, VERUSKA C. ; AQUINO, AFONSO R. . Aplicação e análise da pressão turística como indicador ambiental no Parque Estadual do Jalapão (TO) / Application and analysis of tourist pressure as an environmental indicator in Jalapão State Park (TO, Brazil). Revista Brasileira de Ecoturismo, v. 11, n. 3, p. 311-334, 2018.

    Abstract: O presente artigo visa analisar a aplicabilidade ou não do monitoramento do turismo com o foco na sustentabilidade por meio de indicadores chave do Turismo sustentável propostos pela Organização Mundial do Turismo. A aplicação foi feita em um estudo de caso na unidade de conservação Parque Estadual do Jalapão - PEJ, localizado no Estado do Tocantins, Brasil. Esta é uma pesquisa de caráter interdisciplinar, que teve como norteador o método dedutivo cujo resultado, o indicador Pressão do PEJ, será apresentado. Conclui-se que os pontos chave do turismo sustentável analisados com foco em indicadores ambientais são uma importante ferramenta de avaliação e quantificação desta atividade no destino em estudo e se mostrou adequada para o monitoramento da região. Foi igualmente possível traduzir os principais impactos ambientais que ocorrem nos atrativos e sua intensidade, o que viabilizou uma análise que objetiva traçar caminhos para a correção e prevenção dos impactos apresentados.

    Icon

  • IPEN-DOC 25203

    DONATUS, UYIME ; FERREIRA, RAPHAEL O.; MOGILI, NAGA V.V.; VIVEIROS, BARBARA V.G. de ; MILAGRE, MARIANA X. ; COSTA, ISOLDA . Corrosion and anodizing behaviour of friction stir weldment of AA2198- T851 Al-Cu-Li alloy. Materials Chemistry and Physics, v. 219, p. 493-511, 2018. DOI: 10.1016/j.matchemphys.2018.08.053

    Abstract: Anodizing behaviour of AA2198-T851 friction stir weldment and the corrosion behaviour of unpolished and polished weldments of the alloy have been investigated. Electrochemical and microscopic techniques were employed in the study. The results revealed that the manufacturing-process induced near-surface deformed layer significantly affected the corrosion behaviour of the weldment. Thus, the corrosion behaviour of the weldment in the polished condition (which is the common practice) was different from that of the unpolished one due to the presence of near-surface deformed layer. Anodizing as a corrosion protection method for the weldment caused the formation of pronounced non-uniform oxide layer thicknesses across the weld zones. This was because the weldment oxidized at a higher rate compared with the parent material (PM) due to an increased proportion of Li in solid solution in the stir zone of the weldment.

    Icon

  • IPEN-DOC 25202

    DANTONIO, PAOLA M.; KLEIN, MARIANNE O.; FREIRE, MARIA R.V.B. ; ARAUJO, CAMILA N.; CHIACETTI, ANA C.; CORREA, RICARDO G.. Exploring major signaling cascades in melanomagenesis: a rationale route for targetted skin cancer therapy. Bioscience Reports, v. 38, n. 5, p. BSR20180511-1 - BSR20180511-34, 2018. DOI: 10.1042/BSR20180511

    Abstract: Although most melanoma cases may be treated by surgical intervention upon early diagnosis, a significant portion of patients can still be refractory, presenting low survival rates within 5 years after the discovery of the illness. As a hallmark, melanomas are highly prone to evolve into metastatic sites. Moreover, melanoma tumors are highly resistant to most available drug therapies and their incidence have increased over the years, therefore leading to public health concerns about the development of novel therapies. Therefore, researches are getting deeper in unveiling the mechanisms by which melanoma initiation can be triggered and sustained. In this context, important progress has been achieved regarding the roles and the impact of cellular signaling pathways in melanoma. This knowledge has provided tools for the development of therapies based on the intervention of signal(s) promoted by these cascades. In this review, we summarize the importance of major signaling pathways (mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)-Akt, Wnt, nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB), Janus kinase (JAK)-signal transducer and activator of transcription (STAT), transforming growth factor β (TGF-β) and Notch) in skin homeostasis and melanoma progression. Available and developing melanoma therapies interfering with these signaling cascades are further discussed.

    Icon

  • IPEN-DOC 25209

    LEISTENSCHNEIDER, E.; LEPINE-SZILY, A.; ALVAREZ, M.A.G.; MENDES, D.R.; LICHTENTHALER, R.; AGUIAR, V.A.P.; ASSUNCAO, M.; PAMPA CONDORI, R.; SILVA, U.U. da; FARIA, P.N. de; DESHMUKH, N.; DUARTE, J.G.; GASQUES, L.R.; GUIMARAES, V.; MACCHIONE, E.L.A.; MORAIS, M.C.; MORCELLE, V.; PIRES, K.C.C.; SCARDUELLI, V.B.; SCOTTON, G.; SHORTO, J.M.B. ; ZAGATTO, V.A.B.. Spectroscopy of high-lying resonances in 9Be by the measurement of ( p, p), ( p, d), and ( p, α) reactions with a radioactive 8Li beam. Physical Review C, v. 98, n. 6, p. 064601-1 - 064601-1, 2018. DOI: 10.1103/PhysRevC.98.064601

    Abstract: We measured the 8Li(p, p)8Li, 8Li(p, d)7Li, and 8Li(p, α)5He reactions at low energies using the thick target inverse kinematics method, with a polyethylene [CH2]n target and a radioactive 8Li beam available at the Radioactive Ion Beams in Brazil facility of São Paulo. By measuring simultaneously several reaction channels (p, p), (p, d), and (p, α), the still uncertain high-lying resonances of 9Be, close to the proton threshold, can be studied and their parameters, such as energy, width, and spin parity can be more reliably determined. The experimental excitation functions of the reactions 8Li(p, p)8Li, 8Li(p, d)7Li, and 8Li(p, α)5He were analyzed using the R-matrix theory, which allows us to infer the properties of the resonances. Multichannel R-matrix analysis provides evidence for a significant clustering in the (p, d) channel. The experimental data and the multichannel R-matrix analysis will be presented.

    Icon

  • IPEN-DOC 25201

    CREMA, E.; ZAGATTO, V.A.B.; SHORTO, J.M.B. ; PAES, B.; LUBIAN, J.; SIMOES, R.F.; MONTEIRO, D.S.; HUIZA, J.F.P.; ADDED, N.; MORAIS, M.C.; GOMES, P.R.S.. Reaction mechanisms of the O-18+Cu-63 system at near-barrier energies. Physical Review C, v. 98, n. 4, p. 044614-1 - 044614-10, 2018. DOI: 10.1103/PhysRevC.98.044614

    Abstract: A precise quasielastic excitation function for the O-18 + Cu-63 system has been measured at energies around the Coulomb barrier at theta(LAB) = 161 degrees. The corresponding quasielastic barrier distribution has been derived. Two-neutron-, one-proton-, and alpha-transfer-excitation functions have also been measured at the same energies and angle. Coupled reaction channels calculations were performed to describe the experimental data. Largescale shell-model calculations were performed to derive most of the spectroscopic amplitudes. No surface imaginary potential was necessary for the interaction potential because almost all relevant reaction channels were explicitly included in the calculation. The theoretical results were compared to the experimental quasielastic barrier distribution and a very good agreement was achieved. The comparison of the coupled reaction channel calculations and data has put in evidence several important details of the reaction mechanism of the O-18 + Cu-63 system. The collectivity of the Cu-63 nucleus has important contribution to the reaction mechanism of this system, mainly due to its first 5/2(+) and 7/2(+) states. It was also observed a striking influence on the reaction dynamics of the O-18(2(+)) state, the two-neutron transfer and the reorientation of the target ground-state spin. The best agreement to data was achieved when the nuclear matter diffuseness for the O-18 was assumed equal to 0.60 fm, value that we have derived in a previous paper and that is 10% greater than the O-16 diffuseness. Another significant result was that the two-neutron transfer process is much more relevant than the one-neutron-transfer process, which suggests that the pairing correlation could play an important role in the transfer process of this system.

    Icon

  • IPEN-DOC 25200

    CAVALLARI, ROGER V. ; DE LIMA, NATASHA B. ; SILVA, JULIO C.M. ; BERGAMASHI, VANDERLEI S. ; FERREIRA, JOAO C. . Preparação de suporte de catalisador a partir de biocarbono / Preparation of catalyst support from bio carbon. Periódico Tchê Química, v. 15, n. 30, p. 115-126, 2018.

    Abstract: O uso exagerado de recursos não renováveis, nas ultimas décadas, deflagrou consequências negativas para a sociedade, havendo necessidade de buscar soluções diante dos efeitos deletérios causados pelo avanço da devastação do meio ambiente. Visando contribuir com a ampliação das estratégias de controle de poluentes através do desenvolvimento de tecnologia de baixo custo, o presente trabalho tem como objetivo principal o desenvolvimento de materiais ativos com elevada resistência térmica e boa área especifica para adsorção e impregnação de metais. Neste sentido foram estudados três rotas de tratamento do biocarvão. Na caracterização do biocarbono usaram-se métodos analíticos como: Espectroscopia de Infravermelho (IV), Espectroscopia RAMAM, Medida da Área Superficial (BET), Análise Térmica (TG), Difração de Raios X (DRX) e Microscopia Eletrônica de Varredura (MEV). As diferentes condições de tratamento resultaram em mudanças na estrutura carbonácea do biocarbono com características adequadas para serem utilizados como suporte em catalisadores, apresentando sítios ativos com cargas negativamente carregadas para promover a fixação de metais em sua superfície. Verificou-se também um aumento na área superficial específica, variando entre 341,4 a 749,7 m2 g-1 e alterações nas bandas D e G do carvão e uma alta resistência à temperatura, o que promove reações catalíticas com baixa perda de catalisador.

    Icon

  • IPEN-DOC 25199

    BRITO, TARCISIO; JULIO, ALISON; BERNI, MATEUS; PONCIO, LISIANE de C.; BERNARDES, EMERSON S. ; ARAUJO, HELENA; SAMMETH, MICHAEL; PANE, ATTILIO. Transcriptomic and functional analyses of the piRNA pathway in the Chagas disease vector Rhodnius prolixus. PLOS Neglected Tropical Diseases, v. 12, n. 10, p. e0006760-1 - e0006760-20, 2018. DOI: 10.1371/journal.pntd.0006760

    Abstract: The piRNA pathway is a surveillance system that guarantees oogenesis and adult fertility in a range of animal species. The pathway is centered on PIWI clade Argonaute proteins and the associated small non-coding RNAs termed piRNAs. In this study, we set to investigate the evolutionary conservation of the piRNA pathway in the hemimetabolous insect Rhodnius prolixus. Our transcriptome profiling reveals that core components of the pathway are expressed during previtellogenic stages of oogenesis. Rhodnius' genome harbors four putative piwi orthologs. We show that Rp-piwi2, Rp-piwi3 and Rp-ago3, but not Rp-piwi1 transcripts are produced in the germline tissues and maternally deposited in the mature eggs. Consistent with a role in Rhodnius oogenesis, parental RNAi against the Rp-piwi2, Rp-piwi3 and Rp-ago3 results in severe egg laying and female adult fertility defects. Furthermore, we show that the reduction of the Rp-piwi2 levels by parental RNAi disrupts oogenesis by causing a dramatic loss of trophocytes, egg chamber degeneration and oogenesis arrest. Intriguingly, the putative Rp-Piwi2 protein features a polyglutamine tract at its N-terminal region, which is conserved in PIWI proteins encoded in the genome of other Triatomine species. Together with R. prolixus, these hematophagous insects are primary vectors of the Chagas disease. Thus, our data shed more light on the evolution of the piRNA pathway and provide a framework for the development of new control strategies for Chagas disease insect vectors.

    Icon

  • IPEN-DOC 25198

    BRANT, ANTONIO J.C. ; NAIME, NATALIA ; LUGAO, ADEMAR B. ; PONCE, PATRICIA . Influence of ionizing radiation on biodegradable foam trays for food packaging obtained from irradiated cassava starch. Brazilian Archives of Biology and Technology, v. 61, n. e18160520, 2018. DOI: 10.1590/1678-4324-2018160520

    Abstract: Biodegradable polymers, such as starch, cellulose, and derivatives thereof, are being studied to produce innovative packaging in the most diverse shapes (films, bags, trays, bottles, etc.) to attend this current market trend. The aim of this work was to produce foam trays from cassava starch for food packaging via extrusion followed by thermoforming process. Their formulations were based on unirradiated and γ-irradiated starches at diverse radiation absorbed doses (in kGy) in order to evaluate the influence of the irradiated starches on the physical properties of the trays. Water absorption results showed an irregular increase with the increase of the absorbed dose ( for example, 26.32% and 39.84% for the trays based on unirradiated starch 0 kGy and 1:1 (w/w) mixture of starches 0 kGy and 100.0 kGy, respectively). Other physicochemical properties were evaluated from the starches utilized and the trays obtained. Aerobic biodegradation of the foams by mass loss also was checked in soil burial test.

    Icon

  • IPEN-DOC 25197

    BIANCOLLI, ANA L.G.; HERRANZ, DANIEL; WANG, LIANQIN; STEHLIKOVA, GABRIELA; BANCE-SOUALHI, RACHIDA; PONCE-GONZALEZ, JULIA; OCON, PILAR; TICIANELLI, EDSON A.; WHELLIGAN, DANIEL K.; VARCOE, JOHN R.; SANTIAGO, ELISABETE I. . ETFE-based anion-exchange membrane ionomer powders for alkaline membrane fuel cells: a first performance comparison of head-group chemistry. Journal of Materials Chemistry A, v. 6, n. 47, p. 24330-24341, 2018. DOI: 10.1039/c8ta08309f

    Abstract: In the last few years, the development of radiation-grafted powder-form anion-exchange ionomers (AEI), used in combination with anion-exchange membranes (AEM), has led to the assembly of AEM-based fuel cells (AEMFC) that routinely yield power densities ranging between 1-2 W cm(-2) (with a variety of catalysts). However, to date, only benzyltrimethylammonium-type powder AEIs have been evaluated in AEMFCs. This study presents an initial evaluation of the relative AEMFC power outputs when using a combination of ETFE-based radiation-grafted AEMs and AEIs containing three different head-group chemistries: benzyltrimethylammonium (TMA), benzyl-N-methylpyrrolidinium (MPY), and benzyl-N-methylpiperidinium (MPRD). The results from this study strongly suggest that future research should focus on the development and operando long-term durability testing of AEMs and AEIs containing the MPRD head-group chemistry.

    Icon

  • IPEN-DOC 25196

    ARAUJO, LEANDRO G. de ; MARUMO, JULIO T. . Reaction of ion exchange resins with Fenton's reagent. Environments, v. 5, n. 11, 2018. DOI: 10.3390/environments5110123

    Abstract: One of the most common treatment methods for spent ion exchange resins is their immobilization in cement, which reduces the release of radionuclides into the environment. Although this method is efficient, it considerably increases the final volume of the waste due to its low incorporation capacity. This work aims to evaluate the degradation of ion exchange resins by the Fenton process (H2O2/Fe (2+)). The resin evaluated was a mixture of cationic and anionic resins, both non-radioactive. The reactions were conducted by varying the catalyst concentration (25, 50, 100, and 150 mmol L-1) and the volume of hydrogen peroxide. Three different temperatures were evaluated by varying the flow of reactants, which were 50, 60, and 70 degrees C. Cement specimens were prepared from the treated solutions and two parameters were assessed-namely, final setting time and axial compressive strength. The results showed that the experimental conditions were suitable to dissolve the resins, and the Fe3+ produced as precipitate during the experiments increased the resistance of the final product. The immobilized product complied with the limits established by regulation.

    Icon

  • IPEN-DOC 25195

    AQUINO, SIMONE; LIMA, JOSE E.A. de; NASCIMENTO, ANA P.B. do; REIS, FABRICIO C. . Analysis of fungal contamination in vehicle air filters and their impact as a bioaccumulator on indoor air quality. Air Quality, Atmosphere & Health, v. 11, n. 10, p. 1143-1153, 2018. DOI: 10.1007/s11869-018-0614-0

    Abstract: Studies on air quality within automotive vehicles are an emerging research area in Brazil, especially in the city of São Paulo, one of the most polluted cities in the world and with the largest fleet of vehicles in the country. Indoor air quality is an indicator of environmental health that takes into account, in addition to thermal comfort, factors that interfere in precarious air conditions, such as the presence of fungi, bacteria and carbon dioxide in indoor air-conditioned environments. The objective of the present study was to analyse the fungal contamination in air-conditioning filters collected from 21 automotive vehicles and the study found 17 fungal genera in all samples collected (100%), including toxigenic fungi such as Penicillium, Fusarim and Aspergillus, indicating that indoor air quality can compromise the health of a portion of the population, such as professional drivers. Among the Aspergillus genus, the results showed the presence of the A. flavus, A. niger, A. fumigatus, A. ochraceus and A. clavatus species, which cause severe allergic and pulmonary respiratory diseases. Air in artificially heated environments should provide comfort to its occupants but it may pose a risk to human health if the car filtration system is contaminated by pathogenic fungi.

    Icon

  • IPEN-DOC 25194

    METAIRON, SABRINA ; ZAMBONI, CIBELE B. ; SUZUKI, MIRIAM F. ; BUENO, CARLOS R.. Evaluation of ions and metals in the blood of GRMD dogs submitted to hASCs therapy by NAA and XRF techniques. Applied Radiation and Isotopes, v. 143, p. 107-112, 2019. DOI: 10.1016/j.apradiso.2018.10.024

    Abstract: The elements Br, Ca, Cl, Cr, Fe, K, Mg, Na, P, Rb, S, and Zn were investigated in the whole blood samples of Golden Retriever dogs submitted to cell therapy (hASCs). These analyses were performed over 2 years using Neutron Activation Analysis and X-Ray Fluorescence techniques. The results were compared with control and untreated dog's. A significant increase was observed in K blood levels. There was also variation in blood levels of Br, Cr, Fe, Rb, S, and Zn.

    Icon

  • IPEN-DOC 25193

    FURIGO, ISADORA C.; SUZUKI, MIRIAM F. ; OLIVEIRA, JOAO E. ; RAMOS-LOBO, ANGELA M.; TEIXEIRA, PRYSCILA D.S.; PEDROSO, JOAO A.; ALENCAR, AMANDA de; ZAMPIERI, THAIS T.; BUONFIGLIO, DANIELLA C.; QUARESMA, PAULA G.F.; PRADA, PATRICIA O.; BARTOLINI, PAOLO ; SOARES, CARLOS R.J. ; DONATO JUNIOR, JOSE. Suppression of prolactin secretion partially explains the antidiabetic effect of bromocriptine in ob/ob mice. Endocrinology, v. 160, n. 1, p. 193-204, 2019. DOI: 10.1210/en.2018-00629

    Abstract: Previous studies have shown that bromocriptine mesylate (Bromo) lowers blood glucose levels in adults with type 2 diabetes mellitus; however, the mechanism of action of the antidiabetic effects of Bromo is unclear. As a dopamine receptor agonist, Bromo can alter brain dopamine activity affecting glucose control, but it also suppresses prolactin (Prl) secretion, and Prl levels modulate glucose homeostasis. Thus, the objective of the current study was to investigate whether Bromo improves insulin sensitivity via inhibition of Prl secretion. Male and female ob/ob animals (a mouse model of obesity and insulin resistance) were treated with Bromo and/or Prl. Bromo-treated ob/ob mice exhibited lower serum Prl concentration, improved glucose and insulin tolerance, and increased insulin sensitivity in the liver and skeletal muscle compared with vehicle-treated mice. Prl replacement in Bromo-treated mice normalized serum Prl concentration without inducing hyperprolactinemia. Importantly, Prl replacement partially reversed the improvements in glucose homeostasis caused by Bromo treatment. The effects of the Prl receptor antagonist G129R-hPrl on glucose homeostasis were also investigated. We found that central G129R-hPrl infusion increased insulin tolerance of male ob/ob mice. In summary, our findings indicate that part of Bromo effects on glucose homeostasis are associated with decrease in serum Prl levels. Because G129R-hPrl treatment also improved the insulin sensitivity of ob/ob mice, pharmacological compounds that inhibit Prl signaling may represent a promising therapeutic approach to control blood glucose levels in individuals with insulin resistance.

    Icon

  • IPEN-DOC 25192

    GOTARDELO, DANIEL R. ; COURROL, LILIA C.; BELLINI, MARIA H. ; SILVA, FLAVIA R. de O. ; SOARES, CARLOS R.J. . Porphyrins are increased in the faeces of patients with prostate cancer: a casecontrol study. BMC Cancer, v. 18, n. 1090, 2018. DOI: 10.1186/s12885-018-5030-1

    Abstract: Background: Experimental models of prostate cancer have demonstrated increased levels of protoporphyrin IX (PpIX) in the blood and faeces of mice. Hence, the quantification of these autofluorescent molecules could be hypothesized to be a potential marker for this type of tumour. In this case-control study, the autofluorescence of porphyrins in human faeces from patients with prostate cancer and control subjects was analysed using fluorescence spectroscopy. Methods: First, 3 mL of analytical-grade acetone was added to 0.3 g of faeces, and the mixture was macerated and centrifuged at 4000 rpm for 15 min. The supernatant was analysed spectroscopically. The emission spectra from 550 to 750 nm were obtained by exciting the samples at 405 nm. Results: A significant difference between the samples from control and cancer subjects was established in the spectral region of 670–675 nm (p = 0.000127), which corresponds to a significant increase in faecal porphyrins in patients with cancer. There was no statistically significant correlation between PSA levels and faecal porphyrins. Conclusion: In this preliminary study conducted in humans, the results show a simple and non-invasive method to assess faecal porphyrins, which have the potential to function as a tumour biomarker in patients with prostate cancer. This approach has improved sensitivity and specificity over PSA testing. Additional prospective studies with larger sample sizes are required to validate these findings.

    Icon

  • IPEN-DOC 25191

    SILVA, CLEIDE M.R. da ; CHURA-CHAMBI, ROSA M. ; PEREIRA, LENNON R.; CORDEIRO, YRAIMA; FERREIRA, LUIS C. de S.; MORGANTI, LIGIA . Association of high pressure and alkaline condition for solubilization of inclusion bodies and refolding of the NS1 protein from zika virus. BMC Biotechnology, v. 18, n. 78, 2018. DOI: 10.1186/s12896-018-0486-2

    Abstract: Background: Proteins in inclusion bodies (IBs) present native-like secondary structures. However, chaotropic agents at denaturing concentrations, which are widely used for IB solubilization and subsequent refolding, unfold these secondary structures. Removal of the chaotropes frequently causes reaggregation and poor recovery of bioactive proteins. High hydrostatic pressure (HHP) and alkaline pH are two conditions that, in the presence of low level of chaotropes, have been described as non-denaturing solubilization agents. In the present study we evaluated the strategy of combination of HHP and alkaline pH on the solubilization of IB using as a model an antigenic form of the zika virus (ZIKV) non-structural 1 (NS1) protein. Results: Pressure-treatment (2.4 kbar) of NS1-IBs at a pH of 11.0 induced a low degree of NS1 unfolding and led to solubilization of the IBs, mainly into monomers. After dialysis at pH 8.5, NS1 was refolded and formed soluble oligomers. High (up to 68 mg/liter) NS1 concentrations were obtained by solubilization of NS1-IBs at pH 11 in the presence of arginine (Arg) with a final yield of approximately 80% of total protein content. The process proved to be efficient, quick and did not require further purification steps. Refolded NS1 preserved biological features regarding reactivity with antigen-specific antibodies, including sera of ZIKV-infected patients. The method resulted in an increase of approximately 30-fold over conventional IB solubilization-refolding methods. Conclusions: The present results represent an innovative non-denaturing protein refolding process by means of the concomitant use of HHP and alkaline pH. Application of the reported method allowed the recovery of ZIKV NS1 at a condition that maintained the antigenic properties of the protein.

    Icon

  • IPEN-DOC 25190

    MUCCILLO, REGINALDO ; FLORIO, DANIEL Z. de; MUCCILLO, ELIANA N.S. . Equimolar yttria-stabilized zirconia and samaria-doped ceria solid solutions. Ceramics, v. 1, n. 2, p. 343-352, 2018. DOI: 10.3390/ceramics1020027

    Abstract: Compositions of (ZrO2)0.92(Y2O3)0.08 (zirconia: 8 mol % yttria—8YSZ) and (CeO2)0.8(Sm2O3)0.2 (ceria: 20 mol % samaria—SDC20) ceramic powders were prepared by attrition milling to form an equimolar powder mixture, followed by uniaxial and isostatic pressing. The pellets were quenched to room temperature from 1200 °C, 1300 °C, 1400 °C and 1500 °C to freeze the defects configuration attained at those temperatures. X-ray diffraction analyses, performed in all quenched pellets, show the evolution of the two (8YSZ and SDC20) cubic fluorite structural phases to a single phase at 1500 °C, identified by Rietveld analysis as a tetragonal phase. Impedance spectroscopy analyses were carried out in pellets either quenched or slowly cooled from 1500 °C. Heating the quenched pellets to 1000 °C decreases the electrical resistivity while it increases in the slowly cooled pellets; the decrease is ascribed to annealing of defects created by lattice micro-tensions during quenching while the increase to partial destabilization of the tetragonal phase.

    Icon

  • IPEN-DOC 25189

    BUSTILLOS, OSCAR V. . A fonte de íons por impacto de elétrons na espectrometria de massas. Revista Analytica, v. 16, n. 97, p. 38-39, 2018.

    Icon

  • IPEN-DOC 25155

    SILVA, ANDERSON G.M. da; BATALHA, DANIEL C.; RODRIGUES, THENNER S. ; CANDIDO, EDUARDO G.; LUZ, SULUSMON C.; FREITAS, ISABEL C. de; FONSECA, FABIO C. ; OLIVEIRA, DANIELA C. de; TAYLOR, JASON G.; TORRESI, SUSANA I.C. de; CAMARGO, PEDRO H.C.; FAJARDO, HUMBERTO V.. Sub-15 nm CeO2 nanowires as an efficient nonnoble metal catalyst in the room-temperature oxidation of aniline. Catalysis Science and Technology, v. 8, n. 7, p. 1828-1839, 2018. DOI: 10.1039/c7cy02402a

    Abstract: We described herein the facile synthesis of sub-15 nm CeO2 nanowires based on a hydrothermal method without the use of any capping/stabilizing agent, in which an oriented attachment mechanism took place during the CeO2 nanowire formation. The synthesis of sub-15 nm CeO2 nanowires could be achieved on relatively large scales (∼2.6 grams of nanowires per batch), in high yields (>94%), and at low cost. To date, there are only a limited number of successful attempts towards the synthesis of CeO2 nanowires with such small diameters, and the reported protocols are typically limited to low amounts. The nanowires displayed uniform shapes and sizes, high surface areas, an increased number of oxygen defects sites, and a high proportion of Ce3+/Ce4+ surface species. These features make them promising candidates for oxidation reactions. To this end, we employed the selective oxidation of aniline as a model transformation. The sub-15 nm CeO2 nanowires catalyzed the selective synthesis of nitrosobenzene (up to 98% selectivity) from aniline at room temperature using H2O2 as the oxidant. The effect of solvent and temperature during the catalytic reaction was investigated. We found that such parameters played an important role in the control of the selectivity. The improved catalytic activities observed for the sub-15 nm nanowires could be explained by: i) the uniform morphology with a typical dimension of 11 ± 2 nm in width, which provides higher specific surface areas relative to those of conventional catalysts; ii) the significant concentration of oxygen vacancies and high proportion of Ce3+/Ce4+ species at the surface that represent highly active sites towards oxidation reactions; iii) the crystal growth along the (110) highly catalytically active crystallographic directions, and iv) the mesoporous surface which is easily accessible by liquid substrates. The results reported herein demonstrated high activities under ambient conditions, provided novel insights into selectivities, and may inspire novel metal oxide-based catalysts with desired performances.

    Icon

  • IPEN-DOC 25154

    BARABAS, ROBERTA de C. ; LIMA, ANA C. de S. ; SABUNDJIAN, GAIANE . A panoramic view of nuclear science and technology education worldwide. International Journal of Development Research, v. 8, n. 10, p. 23256-23259, 2018.

    Abstract: Nuclear energy has been used as a source of clean energy with many benefits. Nevertheless, it is still addressed with prejudice. The atomic bombing of Hiroshima and Nagasaki during World War II (1945), the Three Mile Island accident (1979), Chernobyl accident (1986), the crash of the cesium-137 in Goiânia, Brazil (1987), and the accident in Fukushima (2011) may have been responsible for the negative image of nuclear energy. Researches on education have been conducted with students concerning the conceptual and practical issues of nuclear energy. This work aims to review the literature about nuclear energy education around the world in both, elementary school and high school. Since most educational researches on nuclear energy were published after 1980, this literature review covered the researches that have been published since 1980. The data were presented in chronological order. The results from the literature review provided a clear visualization of the global nuclear energy educational scenario, showing that the theme is still addressed with prejudice due to an incorrect view of nuclear energy and a limited view of its benefits. Concerning the science textbooks, the literature reports that the theme should be better addressed, encouraging students to research more about it. The data from this literature review will serve as a reference for a future proposal for a teaching training program for Brazilian science/physics high school teachers using a new teaching approach.

    Icon

  • IPEN-DOC 25153

    BORGES, EDUARDO M. ; SABUNDJIAN, GAIANE ; DAURIA, FRANCESCO; PETRUZZI, ALESSANDRO. Uncertainty calculation in small break LOCA in the emergency core cooling system connected to the hot leg of Angra 2 nuclear power plant. International Journal of Nuclear Energy Science and Technology, v. 12, n. 2, p. 139-160, 2018.

    Abstract: Owing to the occurrence of nuclear accidents, worldwide nuclear regulatory organisations included the analysis of accidents considered as design basis accidents – Loss of Coolant Accident (large and small-break, LBLOCA or SBLOCA) – in the safety analysis reports of nuclear facilities. In Brazil, the tool selected by the licensing authority, Comissão Nacional de Energia Nuclear (CNEN), is RELAP5 Code. The aim of this paper is the evaluation of the performance of the Emergency Core Cooling System (ECCS) of Angra 2 nuclear reactor during SBLOCA. In this study, the RELAP5 code and the Code Internal Assessment of Uncertainty (CIAU) were used to simulate and analyse the uncertainties of the results. The postulated accident is the SBLOCA in the hot leg connected to the ECCS described in the Final Safety Analysis Report of Angra 2 (FSAR/A2). The results from this study were satisfactory when compared with the FSAR/A2.

    Icon

  • IPEN-DOC 25152

    BAPTISTA FILHO, B.D. ; CABRAL, E.L.L. ; BARROSO, A.C.O. . An R-package for water and steam properties for scientific and general use. International Journal of Nuclear Energy Science and Technology, v. 12, n. 2, p. 172-195, 2018.

    Abstract: The International Association for the Properties of Water and Steam (IAPWS) develops formulations for the calculation of thermophysical properties of water as a function of different combinations of temperature, density, pressure, enthalpy, and entropy. These properties are useful for scientists and nuclear, chemical, and mechanical engineers who analyse experimental data or are involved with projects and equipment development, like heat exchangers, turbines, or nuclear power reactors. The IAPWS-95 formulation solves the fundamental equation of Helmholtz free energy as a function of temperature and density. This paper gives a description of how these equations are solved and exemplifies the use of a package developed for the free platform R. The IAPWS95 package was developed to help users to get access to the IAPWS-95 formulation in a free software environment which is growing exponentially. Transport properties were programmed using other IAPWS releases. The examples consider the uncertainty analysis of thermal parameters of a nuclear power reactor and the preparation of tables and graphs of water properties.

    Icon

  • IPEN-DOC 25151

    ICHIKAWA, RODRIGO U. ; PARRA, JOAO P.R.L.L.; MARTINS, MURILLO L.; YOSHITO, WALTER K. ; SAEKI, MARGARIDA J.; TURRILLAS, XAVIER; MARTINEZ, LUIS G. . Size-strain analysis of iron-excess Mn–Zn ferrite nanoparticles using synchrotron diffraction and its correlation with magnetic saturation and isoelectric pH. Journal of Nanoscience and Nanotechnology, v. 18, n. 8, p. 5697-5703, 2018. DOI: 10.1166/jnn.2018.15446

    Abstract: Iron-excess Mn–Zn ferrite nanoparticles were prepared by coprecipitation with sodium hydroxide (NaOH) at different concentrations (0.1, 0.2, 0.5 and 1.0 mol/L). The results of X-ray diffraction (XRD) analysis using Whole Powder Pattern Modeling (WPPM) showed that higher concentrations of NaOH promote crystallite growth and broader dispersion in crystallite sizes. Energy dispersive X-ray spectroscopy indicates that zinc loss is noticeable when [NaOH] ≥ 0.2 mol/L. XRD revealed also a significant less-crystalline phase contribution alongside the main peaks of the nanocrystalline cubic spinel ferrite phase. The less-crystalline fraction is lower for the ferrite obtained with 0.2 mol/L of NaOH, being about 50% and more than 70% for the other samples. Despite of the less-crystalline fraction and the excess of iron, no secondary phases were detected. The Warren curves showed that the concentration of NaOH significantly influences the microstrain in the crystallites, being smaller for the sample obtained with NaOH at 0.2 mol/L. The sample prepared with this condition presented the better properties to be used as magnetic tracer in clinical diagnoses combining small mean crystallite size, low microstrain, which resulted in materials with higher magnetic saturation and high surface charge under blood pH.

    Icon

  • IPEN-DOC 25111

    CUNICO, PATRICIA ; KUMAR, ANU; ALCANTARA, RAQUEL R. ; FUNGARO, DENISE A. . Adsorption of solophenyl dyes from aqueous solution by modified nanozeolite from bottom ash and its toxicity to C. dubia. Current Nanomaterials, v. 2, n. 2, p. 95-103, 2017. DOI: 10.2174/2405461503666180201152351

    Abstract: Background: It is known that wastewater from textile industries are responsible for producing large amounts of highly contaminated effluents by various types of synthetic dyes. These compounds can be toxic, and in some cases, are carcinogenic and mutagenic and its removal is recommended. Application: In the area of water purification, nanomaterials have been applied for removal of several compounds. Of the four classes of nanomaterials, zeolites have demonstrated good results for the removal of dyes. Nanozeolite synthesized from bottom ash and modified with hexadecyltrimethylamonium (ZMB) was used as adsorbent to removal of Solophenyl Navy (SN), Solophenyl Turquoise (ST) and their hydrolyzed forms (SNH and STH, respectively) from simulated textile wastewater. Method: The physical-chemical characterization of materials was presented by using relevant analytical methods (XRD, SEM, BET surface area, etc.). Effects of parameters such as initial dye concentration, contact time and equilibrium adsorption were evaluated. The adsorption kinetics followed the pseudo-second-order model. Results: Langmuir isotherm model shows the best fit for most dyes-ZMB systems. In order to identify if ZMB presented toxicity for the environment, bioassay and toxicity identification evaluation (TIE) with C. dubia were performed. The leached of ZMB was toxic to daphinids (11.3 TU). Conclusion: TIE results appointed that the main cause of the toxicity could be due the surfactant and metal ions presents in aqueous solution.

    Icon

  • IPEN-DOC 25149

    WETTER, NIKLAUS U. ; MIRANDA, ADRIANA R. de ; PECORARO, EDISON; RIBEIRO, SIDNEY J.L.; JIMENEZ-VILLAR, ERNESTO . Dynamic random lasing in silica aerogel doped with rhodamine 6G. RSC Advances, v. 8, n. 52, p. 29678-29685, 2018. DOI: 10.1039/c8ra04561e

    Abstract: Silica aerogel is a lightweight material, well known for its good mechanical and thermal characteristics, but its optical properties have received less attention, because it is weakly scattering. Here we present for the first time the lasing properties and their complex dynamics of silica aerogel doped with R6G. It is shown that the Q factors of the lasing modes determine the operation of the laser, being either resonant or ASE-lasing. For resonant lasing, the number of resonators is easily varied and the number of modes in a single resonator and their emission frequency can be dynamically adjusted, making this a truly versatile photonics material.

    Icon

  • IPEN-DOC 25148

    WANG, JAMES S.; KAWA, S.R.; COLLATZ, G.J.; SASAKAWA, MOTOKI; GATTI, LUCIANA V. ; MACHIDA, TOSHINOBU; LIU, YUPING; MANYIN, MICHAEL E.. A global synthesis inversion analysis of recent variability in CO2 fluxes using GOSAT and in situ observations. Atmospheric Chemistry and Physics, v. 18, n. 15, p. 11097-11124, 2018. DOI: 10.5194/acp-18-11097-2018

    Abstract: The precise contribution of the two major sinks for anthropogenic CO2 emissions, terrestrial vegetation and the ocean, and their location and year-to-year variability are not well understood. Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 are expected to benefit from the increasing measurement density brought by recent in situ and remote CO2 observations.We uniquely apply a batch Bayesian synthesis inversion at relatively high resolution to in situ surface observations and bias-corrected GOSAT satellite column CO2 retrievals to deduce the global distributions of natural CO2 fluxes during 2009–2010. The GOSAT inversion is generally better constrained than the in situ inversion, with smaller posterior regional flux uncertainties and correlations, because of greater spatial coverage, except over North America and northern and southern high-latitude oceans. Complementarity of the in situ and GOSAT data enhances uncertainty reductions in a joint inversion; however, remaining coverage gaps, including those associated with spatial and temporal sampling biases in the passive satellite measurements, still limit the ability to accurately resolve fluxes down to the sub-continental or subocean basin scale. The GOSAT inversion produces a shift in the global CO2 sink from the tropics to the north and south relative to the prior, and an increased source in the tropics of 2 PgC yr􀀀1 relative to the in situ inversion, similar to what is seen in studies using other inversion approaches. This result may be driven by sampling and residual retrieval biases in the GOSAT data, as suggested by significant discrepancies between posterior CO2 distributions and surface in situ and HIPPO mission aircraft data. While the shift in the global sink appears to be a robust feature of the inversions, the partitioning of the sink between land and ocean in the inversions using either in situ or GOSAT data is found to be sensitive to prior uncertainties because of negative correlations in the flux errors. The GOSAT inversion indicates significantly less CO2 uptake in the summer of 2010 than in 2009 across northern regions, consistent with the impact of observed severe heat waves and drought. However, observations from an in situ network in Siberia imply that the GOSAT inversion exaggerates the 2010–2009 difference in uptake in that region, while the prior CASA-GFED model of net ecosystem production and fire emissions reasonably estimates that quantity. The prior, in situ posterior, and GOSAT posterior all indicate greater uptake over North America in spring to early summer of 2010 than in 2009, consistent with wetter conditions. The GOSAT inversion does not show the expected impact on fluxes of a 2010 drought in the Amazon; evaluation of posterior mole fractions against local aircraft profiles suggests that time-varying GOSAT coverage can bias the estimation of interannual flux variability in this region.

    Icon

  • IPEN-DOC 25147

    VINAGRE, CARMEN G.; FREITAS, FATIMA R.; MESQUITA, CARLOS H. de ; VINAGRE, JULIANA C.; MARIANI, ANA C.; KALIL-FILHO, ROBERTO; MARANHAO, RAUL C.. Removal of chylomicron remnants from the bloodstream is delayed in aged subjects. Aging and Disease, v. 9, n. 4, p. 748-754, 2018. DOI: 10.14336/AD.2017.1003

    Abstract: Dietary fats absorbed in the intestine are transported in the circulation as chylomicrons and remnants that have atherogenic potential. Although postprandial lipidemia is increased in older subjects, the specific chylomicron metabolism has not been explored in older subjects nor compared to young subjects, which is the focus of this study. After a 12 h fast, artificially-made emulsions similar to lymph chylomicrons and doubly labeled with radioactive cholesteryl esters and triglycerides were intravenously injected in 23 older (66±4 years) and 20 young (24±3 years) subjects. Sequential blood samples were collected to determine fractional clearance rates (FCR, in min-1) by compartmental analysis. Older subjects had higher LDL-cholesterol (p<0.001) and triglycerides (p<0.0001) than young subjects; HDL-cholesterol presented no difference. The emulsion cholesteryl-ester FCR was lower in older subjects compared to the young (p=0.0001). The emulsion triglyceride FCR did not differ in the two groups. Tested in vitro, however, the lipolysis of the emulsion triglycerides was less intense in the older than in the young subjects. As delayed removal of remnants, indicated by the pronouncedly smaller cholesteryl ester FCR, is related to the presence of cardiovascular diseases, this can be a risk factor which could accelerate atherogenic complications occurring in aged subjects

    Icon

  • IPEN-DOC 25146

    VILLEGAS, GETHZEMANI M.E.; MORSELLI, GIOVANNI R. ; GONZALEZ-PEREZ, GIOVANNI ; LUGAO, ADEMAR B. . Enhancement swelling properties of PVGA hydrogel by alternative radiation crosslinking route. Radiation Physics and Chemistry, v. 153, p. 44-50, 2018. DOI: 10.1016/j.radphyschem.2018.08.038

    Abstract: The development of environmentally friendly materials based on non-toxic absorbent polymers, which can ensure high water absorption for several applications in biomedical or agricultural areas, is one of the most complexes problems. In the literature, the non-toxic biodegradable polymer poly(vinyl alcohol) (PVA) was chemically modified with glyoxylic acid to obtain poly(vinylglyoxylic acid) (PVGA) as a biodegradable superabsorbent hydrogel polymer (SHAP), but in fact, the chemical crosslinking reaction decreases the water absorption capacity. In order to crosslink PVGA without losing its absorbent capacity; an alternative radiationcrosslink route has been studied. Radiation-induced crosslinking in the main C-C chain of PVGA where not all free hydrophilic groups (COOH) are involved in a crosslinking reaction as occurs in a traditional chemical reaction. The aim of this work was not only the chemical modification of 99% hydrolyzed PVA to obtain the linear and non-crosslinked PVGA at certain conditions, but also radiation crosslinking at different doses, at dose rate of 5 kGy h−1 attempting to increase the superabsorbent capacity. The samples were characterized by Scanning Electron Microscopy (SEM), Thermo-gravimetrical Analysis (TGA), Nuclear Magnetic Resonance (1H) (NMR) and Infrared Spectroscopy (FTIR). The swelling behavior was measured gravimetrically in different solvents as pure water, buffer pH 3, 7 and 10. Results showed that radiation-crosslink route improves the swelling behavior of PVGA in approximately 215% when compared with PVGA chemically crosslinked, swelled in pure water.

    Icon

  • IPEN-DOC 25145

    VARA-VELA, ANGEL; ANDRADE, MARIA de F.; ZHANG, YANG; KUMAR, PRASHANT; YNOUE, RITA Y.; SOUTO-OLIVEIRA, CARLOS E.; LOPES, FABIO J. da S. ; LANDULFO, EDUARDO . Modeling of atmospheric aerosol properties in the São Paulo metropolitan area: impact of biomass burning. Journal of Geophysical Research: Atmospheres, v. 123, n. 17, p. 9935-9956, 2018. DOI: 10.1029/2018JD028768

    Abstract: Smoke particles ejected into the atmosphere from biomass burning can modify the atmospheric composition around and even far from the sources. In late winter and early spring, biomass burning emissions from inland regions can be efficiently transported to urban areas in southeastern South America, thus affecting air quality in those areas. In this study, the Weather Research and Forecasting with Chemistry model was applied in order to investigate the impact of biomass burning sources on aerosol loadings and properties over the São Paulo Metropolitan Area (SPMA), in southeastern Brazil, during the period from 19 August to 3 September 2014. The model performance was evaluated using available aerosol measurements from the Narrowing the Uncertainties on Aerosol and Climate Change in São Paulo State project. The combined application of aerosol data and Weather Research and Forecasting with Chemistry simulations made it possible to represent some of the most important aerosol properties, such as particle number concentration and cloud condensation nuclei activation, in addition to evaluation of the impact of biomass burning by analyzing a 5‐day transport event, from 22 to 26 August 2014. During this transport event, differences in the average predicted PM2.5 concentration reached 15 μg/m3 (peaking at 20 μg/m3 during the nighttime hours) over the SPMA, compared with 35 μg/m3 over inland areas northwest and north of the SPMA. Biomass burning accounted for up to 20% of the baseline particle number concentration‐ and cloud condensation nuclei‐weighted relative differences over the SPMA (2,300 and 1,400 cm−3, respectively).

    Icon

  • IPEN-DOC 25144

    TOMINAGA, FLAVIO K. ; BATISTA, ANA P. dos S.; TEIXEIRA, ANTONIO C.S.C.; BORRELY, SUELI I. . Degradation of diclofenac by electron beam irradiaton: Toxicitiy removal, by-products identification and effect of another pharmaceutical compound. Journal of Environmental Chemical Engineering, v. 6, n. 4, p. 4605-4611, 2018. DOI: 10.1016/j.jece.2018.06.065

    Abstract: Water contamination by the anti-inflammatory drug diclofenac (DCF) is a consequence of its incomplete removal in wastewater and sewage treatment plants, which is potentialized by interactions with other pharmaceutical contaminants. In this context, electron beam irradiation (EBI) has been considered a clean technology for degrading pharmaceutical compounds in water. Nevertheless, the identification of DCF by-products and their correlation with biological recalcitrance and acute toxicity are poorly understood. In this study, the V. fischeri test was used to characterize DCF toxicity in the absence and presence of fluoxetine (FLX), prior and after irradiation. The results showed complete DCF degradation at low dose (5 kGy). DCF concentration followed pseudo first-order decay with respect to the absorbed, with k0 = (1.33 ± 0.10) kGy−1 (DCF) and k0 = (0.90 ± 0.12) kGy−1 (DCF+FLX). In contrast, negligible TOC removal was observed even at 7.5 kGy, with the formation of recalcitrant, non-biodegradable by-products, as also suggested by the respirometry test. Despite that, the toxicity of the DCF solution diminished from (19.6 ± 1.6) TU to (6.2 ± 2.3) TU, and from (6.8 ± 0.9) TU to (3.1 ± 0.2) TU, in the absence and presence of FLX, respectively, after irradiation up to 5 kGy. Four of the eleven by-products identified by direct-injection MS were easily degraded by EBI, and one (C13H14ClNO5) was considered the least recalcitrant but the most toxic. Based on these results, a possible DCF degradation pathway is proposed, involving hydroxylation and oxidation of aromatic rings, dehalogenation and C−N bond cleavage.

    Icon

  • IPEN-DOC 25143

    SOUZA, J.P. ; GROSSO, R.L. ; MUCCILLO, R. ; MUCCILLO, E.N.S. . Phase composition and ionic conductivity of zirconia stabilized with scandia and europia. Materials Letters, v. 229, p. 53-56, 2018. DOI: 10.1016/j.matlet.2018.06.091

    Abstract: Sintered specimens of zirconia-10 mol% scandia pure and codoped (up to 1.25 mol%) with europium sexquioxide were prepared by solid-state synthesis, aiming to stabilize at room temperature the high-conductivity cubic phase. High-temperature X-ray diffraction and differential scanning calorimetry results reveal that small amounts of the codopant reduce the enthalpy of phase transition, and full stabilization is evidenced for 1 mol% europium sexquioxide. The low-temperature (<600 C) ionic conductivity increases with increasing codopant content.

    Icon

  • IPEN-DOC 25142

    SOARES, EDSON P. ; CASINI, JULIO C.S.; VIEIRA, LIGIA S.; SILVA, FRANKS M.; FARIA, RUBENS N. de ; TAKIISHI, HIDETOSHI . Effect of hydrogen decrepitation pressure on the particle size of rare earth based alloys for Ni-MH battery production. Materials Science Forum, v. 930, p. 637-642, 2018. DOI: 10.4028/www.scientific.net/MSF.930.637

    Abstract: This paper presents the results obtained from the hydrogenation and decrepitation of three LaNi-based alloys, La0.7Mg0.3Al0.3Mn0.4Co0.5Ni3.8, La0.7Mg0.3Al0.3Mn0.4Cu0.5Ni3.8 and La0.7Mg0.3Al0.3Mn0.4Sn0.5Ni3.8, in the as-cast condition. The procedure for decrepitating the alloys to be used in the negative electrode of the batteries was carried out using a combination of various hydrogen pressures (2-9 bar) at room temperature. At 2 bar of H2 it was revealed that Co, Cu and Sn have influence on the microstructures of the hydrogenated alloys and on the efficiency of hydrogen decrepitation. None of these alloys required thermal heating to activate and start the hydrogen absorption process. The decrepitated materials were characterized by scanning electron microscopy (SEM). The electrochemical measurements were performed using the tested negative electrode between two Ni(OH)2 electrodes as a battery cell.

    Icon

  • IPEN-DOC 25141

    SILVA, FLAVIA R.O. ; YOSHITO, WALTER K. ; COSENTINO, IVANA C. ; BRESSIANI, ANA H.A. ; LIMA, NELSON B. . Synthesis and characterization of novel crystalline mesoporous beta-tricalcium phosphate nanoparticles. Materials Science Forum, v. 930, p. 63-66, 2018. DOI: 10.4028/www.scientific.net/MSF.930.63

    Abstract: A nano-sized magnesium substituted beta-tricalcium phosphate (Mg:β-TCP) was synthesized by an aqueous precipitation method, at room temperature, in one single step. In the present study, the novel and stable Mg:β-TCP resulted in a crystalline and spherical nanoparticles (diameter of approximately 20 nm) with mesoporous structures and a high specific surface area (about 574 m2/g). These special characteristics make this novel crystalline mesoporous Mg: β-TCP nanoparticles ideal candidates for drug delivery system and a promising non-viral vector for gene therapy.

    Icon

  • IPEN-DOC 25140

    SILVA, RODRIGO P. da; TUDELA, DIEGO R.G.; MUNITA, CASIMIRO S. ; HAZENFRATZ, ROBERTO ; TATUMI, SONIA H.; YEE, MARCIO; MITTANI, JUAN C.R.. Firing temperature determination and thermoluminescence dating of a brick with cuneiform characters found in the ruins of Ancient Babylon / Determinação da temperatura de queima e datação por termoluminescência de um tijolo com caracteres cuneiformes encontrado nas ruínas da antiga Babilônia. Revista do Museu de Arqueologia e Etnologia, n. 28, p. 58-69, 2017. DOI: 10.11606/issn.2448-1750.revmae.2017.133911

    Abstract: This paper aims to study a brick with inscriptions in cuneiform characters in which the sentences are almost complete. Typological studies in agreement with historical records suggest that the tablet was manufactured in the 6th century BCE during the dynasty of Nebuchadnezzar II, Great King of Babylon. The sample was studied by X-ray diffraction analysis (XRD), electron paramagnetic resonance (EPR), thermoluminescence (TL), and instrumental neutron activation analysis (INAA) techniques. The results showed that the brick is 2350 years old (± 40) and its firing temperature was lower than 400 °C.

    Icon

  • IPEN-DOC 25139

    SILVA, DANILO L.C. e ; KASSAB, LUCIANA R.P.; SANTOS, ANTONIO D. dos ; PILLIS, MARINA F.. Evaluation of carbon thin films using raman spectroscopy. Materials Research, v. 21, n. 4, 2018. DOI: 10.1590/1980-5373-MR-2017-0787

    Abstract: Carbon thin films deposited by the magnetron sputtering technique were evaluated by Raman spectroscopy to study the influence on their crystallinity caused by different parameters like the carbon deposition time, the different buffer-layers and substrates employed and also two distinct heat treatments. The present results showed that the choice of these parameters plays an important role in the production of these films. The results also indicate the possibility of using the technique for the production of carbon thin films to be employed in future in applications with controlled content of structural defects, predominance of ordered sp2 bondings and tendency of graphitization.

    Icon

  • IPEN-DOC 25138

    SILVA, J.O.; NONATO, F.B.C.; SAMPAIO, F.G.A.; CALDAS, L.V.E. . Evaluation of some dosimetric properties of a dedicated plane parallel ionization chamber for radiotherapy electron beams. Brazilian Journal of Radiation Sciences, v. 6, n. 3, p. 1-13, 2018. DOI: 10.15392/bjrs.v6i3.547

    Abstract: Ionization chambers are the reference detectors for electron beam dosimetry. In this paper a dedicated radiotherapy plane parallel ionization chamber manufactured with low cost materials is presented for dosimetry in electron beams. The ionization chamber tested has a sensitive volume of 0.4 cm³. Both the collecting electrode and the guard ring were painted with a homogeneous mixture of nail polish and graphite. The dedicated ionization chamber presented a linear response with electron absorbed dose within the range 0.5 to 8.0 Gy, an increase of its response with the field size increasing, an angular dependence within ±5°, as recommended by international standards, and a polarity effect of 0.78% according to the field size. Considering the results obtained, it is possible to conclude that the plane parallel ionization chamber tested in this work presents potential use for elec - tron beam dosimetry in clinical routine.

    Icon

  • IPEN-DOC 25137

    SELLERA, FABIO P.; GARGANO, RONALDO G.; ANJOS, CAROLINA dos; BAPTISTA, MAURICIO da S.; RIBEIRO, MARTHA S. ; POGLIANI, FABIO C.. Methylene blue-mediated antimicrobial photodynamic therapy: a novel strategy for digital dermatitis-associated sole ulcer in a cow – A case report. Photodiagnosis and Photodynamic Therapy, v. 24, p. 121-122, 2018. DOI: 10.1016/j.pdpdt.2018.09.004

    Icon

  • IPEN-DOC 25136

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . EPR response of yttria micro rods activated by europium. Journal of Alloys and Compounds, v. 764, p. 136-141, 2018. DOI: 10.1016/j.jallcom.2018.06.063

    Abstract: Rare earth (RE) materials present excellent properties, which importance is recognized worldwide. Innovation approaches in energy, medicine, communication, transportation, militarism, and radiation dosimetry consist in RE based materials. As yttrium oxide (Y2O3) exhibits intrinsic lattice characteristics that enable doping with others RE elements (Y2O3:RE), new materials with promising characteristics can be developed. This work aims to evaluate EPR response of europium-yttria (Y2O3:Eu) rods obtained by bio-prototyping. Ceramic rods containing up to 10 at.%Eu were irradiated with gamma doses from 0.001 to 150 kGy and evaluated by Electron Paramagnetic Resonance (EPR) at room temperature with X-band EPR. Based on results, Y2O3:Eu rods with 2 at.%Eu exhibited the most significant response, in which linear behavior arose from 0.001 up to 50 kGy. Fading and thermal annealing evaluations revealed that 2 at%.Eu improved dosimetric characteristics of yttria remarkably. These innovative findings afford that Y2O3:Eu is a promising material for radiation dosimetry.

    Icon

  • IPEN-DOC 25135

    ROSSETTO, CLEUSA M.; ICHIKAWA, RODRIGO U. ; MARTINEZ, LUIS G. ; CAREZZATO, GERALDO L. ; CARVALHO, ALEXANDRE M.G.; TURRILLAS, XAVIER. In situ hydration of sulfoaluminate cement mixtures monitored by synchrotron X-Ray diffraction. Materials Science Forum, v. 930, p. 153-157, 2018. DOI: 10.4028/www.scientific.net/MSF.930.153

    Abstract: Mixtures of calcium sulfoaluminate and Portland clinkers with gypsum were hydrated with deionized water. The pastes were introduced in 0.7 mm borosilicate capillary tubes and kept at 40 ºC while diffraction patterns were collected every 35 s for approximately 3 hours with a monochromatic radiation of 12 keV at the XRD1 beamline of the Laboratório Nacional de Luz Síncrotron (LNLS) in Campinas, SP - Brazil. The main crystalline phases (C2S, C3S, ettringite, ye’elemite and gypsum) involved in the hydration were quantified by Rietveld analysis. The most noticeable fact was the absence of portlandite as a crystalline precipitate, most likely due to the capture of calcium ions to form ettringite.

    Icon

  • IPEN-DOC 25134

    RICCI, GIANNINA; SANTOS, DANIEL W.; KOVACS, JOSEPH A.; NISHIKAKU, ANGELA S.; SANDES-FREITAS, TAINA V. de; RODRIGUES, ANDERSON M.; KUTTY, GEETHA; AFFONSO, REGINA ; SILVA, HELIO T.; MEDINA-PESTANA, JOSE O.; FRANCO, MARCELLO F. de; COLOMBO, ARNALDO L.. Genetic diversity of Pneumocystis jirovecii from a cluster of cases of pneumonia in renal transplant patients: Cross-sectional study. Mycoses, v. 61, n. 11, p. 845-852, 2018. DOI: 10.1111/myc.12823

    Abstract: Pneumocystis jirovecii can cause severe potentially life-threatening pneumonia (PCP) in kidney transplant patients. Prophylaxis of patients against PCP in this setting is usually performed during 6 months after transplantation. The aim of this study is to describe the molecular epidemiology of a cluster of PCP in renal transplant recipients in Brazil. Renal transplant patients who developed PCP between May and December 2011 had their formalin-fixed paraffin-embedded (FFPE) lung biopsy samples analysed. Pneumocystis jirovecii 23S mitochondrial large subunit of ribosomal RNA (23S mtLSU-rRNA), 26S rRNA, and dihydropteroate synthase (DHPS) genes were amplified by polymerase chain reaction (PCR), sequenced, and analysed for genetic variation. During the study period, 17 patients developed PCP (only four infections were documented within the first year after transplantation) and six (35.3%) died. Thirty FFPE samples from 11 patients, including one external control HIV-infected patient, had fungal DNA successfully extracted for further amplification and sequencing for all three genes. A total of five genotypes were identified among the 10 infected patients. Of note, four patients were infected by more than one genotype and seven patients were infected by the same genotype. DNA extracted from FFPE samples can be used for genotyping; this approach allowed us to demonstrate that multiple P. jirovecii strains were responsible for this cluster, and one genotype was found infecting seven patients. The knowledge of the causative agents of PCP may help to develop new initiatives for control and prevention of PCP among patients undergoing renal transplant and improve routine PCP prophylaxis.

    Icon

  • IPEN-DOC 25133

    AKBARI-JEYHOUNI, REZA; OCHBELAGH, DARIUSH R.; MAIORINO, JOSE R.; DAURIA, FRANCESCO; STEFANI, GIOVANNI L. de . The utilization of thorium in Small Modular Reactors – Part I: neutronic assessment. Annals of Nuclear Energy, v. 120, p. 422-430, 2018. DOI: 10.1016/j.anucene.2018.06.013

    Abstract: This work presents a neutronic assessment to convert a Small Modular Reactor (SMR) with uranium core to the thorium mixed oxide core with minimum possible changes in the geometry and main parameters of SMR core. This option is due to most of SMR are designed to be strongly poisoned in the beginning of cycle and to have a long cycle. Thorium can be used as an absorber in the beginning of the cycle and also be used as a fertile material during the cycle, it seems to be a good option to use (Th/U)O2 as SMR’s fuel. The main neutronic objectives of this study is achieving longer cycle length for SMR by using the minimum possible amount of burnable poison and soluble boron in comparison with reference core. The Korean SMART reactor as a certified design SMR has been chosen as the reference core. The calculations have been performed by MCNP code for homogeneous and heterogeneous seed and blanket concept fuel assemblies. The results obtained show that the heterogeneous fuel assembly is the one which gives longer cycle length and used lower amount of burnable poison and soluble boron, and also consumes almost the same amount of 235U.

    Icon

  • IPEN-DOC 25132

    PORFIRIO, DARILENA M.; MONTEIRO, LUCILENA R. ; COSTA, MARCONDES L. da. Rainwater geochemistry inside the Barcarena power station at the mouth of the Tocantins River. Environmental Technology, 2018. DOI: 10.1080/09593330.2018.1516801

    Abstract: Most of South America lacks studies on rainwater composition. The present study evaluates rainwater composition and bulk deposition inside Barcarena power station, located at the mouth of the Tocantins River with Amazon River in Brazil. In 2012, 24-h rainwater samples were collected inside the ELETRONORTE power plant (n = 93), and pH, EC, cations and anions were analyzed. In order of abundance, the rainwater ions were Na+ > Cl− > SO4−2 > Ca+2 > K+ > F− > Mg+2 > NH4+-N > NO3−-N. pH values ranged from 4.5 to 6.9, with 17 events with pH <5.6 and 5 events with pH < 5.0. Sodium and Cl− were the dominant ions with sea salt as main contribution. Acidity, enrichment factors and principal component analysis (PCA) indicate that F−, SO4−2 and NO3−-N in the rainwater came from anthropogenic sources. Fluoride correlated strongly (>0.85) with Ca+2 and Mg+2, likely originated from same source in the aluminum production chain. Potassium originated from a mixture of anthropogenic and natural sources, with a good correlation (>0.70) with NO3−-N and NH4+-N, indicating biomass burning and fertilizer origins. In 2012, Barcarena total bulk deposition ranged from 14,070 to 17,890 mg m−2 y−1 with significant contributions of SO4−2 (2,385 to 2,851 mg m−2 y−1), F− (419 to 479 mg m−2 y−1) and NO3−-N (128 to 280 mg m−2 y−1). EC values (4 to 254 µS cm−1) indicated a medium site pollution severity (> 175 µS cm−1), which increased the risk of damage to electrical components.

    Icon

  • IPEN-DOC 25131

    POLO, IVON O. ; SANTOS, WILLIAM S. ; CALDAS, LINDA V.E. . Modelling the absorbed dose rate of the beta standard BSS2 147Pm source. Applied Radiation and Isotopes, v. 140, p. 83-86, 2018. DOI: 10.1016/j.apradiso.2018.06.015

    Abstract: The dosimetric measurements of 147Pm beta radiation beams have limitations due to their low energy, low dose rate, great dispersion and attenuation in air or tissue. In this work, the Monte Carlo model was developed for a 147Pm absorbed dose rate determination. This model consists of an extrapolation chamber and a 147Pm beta radiation source. Moreover, the absorbed dose rate was determined by experimental measurements and the MCNP Monte Carlo code was used. The relative number of particles that crossed the radioactive source window and the particles that crossed the extrapolation chamber entrance window were determined. The source fluence spectrum was also determined. The results of the simulation and the experimental calculations are in agreement with the absorbed dose rate from the PTB calibration certificate. The results obtained are considered acceptable, and they agree within the uncertainties. The difference between the experimental result and that from the Monte Carlo model, compared to that from the calibration certificate, was only 0.8% in both cases.

    Icon

  • IPEN-DOC 25130

    POLO, IVON O. ; SANTOS, WILLIAM de S. ; CALDAS, LINDA V.E. . Determination of correction factors in beta radiation beams using Monte Carlo method. Applied Radiation and Isotopes, v. 140, p. 50-54, 2018. DOI: 10.1016/j.apradiso.2018.06.011

    Abstract: The absorbed dose rate is the main characterization quantity for beta radiation. The extrapolation chamber is considered the primary standard instrument. To determine absorbed dose rates in beta radiation beams, it is necessary to establish several correction factors. In this work, the correction factors for the backscatter due to the collecting electrode and to the guard ring, and the correction factor for Bremsstrahlung in beta secondary standard radiation beams are presented. For this purpose, the Monte Carlo method was applied. The results obtained are considered acceptable, and they agree within the uncertainties. The differences between the backscatter factors determined by the Monte Carlo method and those of the ISO standard were 0.6%, 0.9% and 2.04% for 90Sr/90Y, 85Kr and 147Pm sources respectively. The differences between the Bremsstrahlung factors determined by the Monte Carlo method and those of the ISO were 0.25%, 0.6% and 1% for 90Sr/90Y, 85Kr and 147Pm sources respectively.

    Icon

  • IPEN-DOC 25129

    PILLIS, MARINA F. ; OLIVEIRA, MARA C.L. de; ANTUNES, RENATO A.. Surface chemistry and the corrosion behavior of magnetron sputtered niobium oxide films in sulfuric acid solution. Applied Surface Science, v. 462, p. 344-352, 2018. DOI: 10.1016/j.apsusc.2018.08.123

    Abstract: In this work, magnetron sputtered Nb2O5 films were obtained at two different deposition times. The surface chemistry of the deposited layers was investigated by X-ray photoelectron spectroscopy (XPS). The corrosion behavior was assessed by electrochemical impedance spectroscopy, potentiodynamic polarization and potentiostatic polarization tests in 0.5 M H2SO4 + 2 ppm HF solution at room temperature. The Nb5+/Nb4+ ratio decreased with the deposition time, leading to a higher surface activity for the film obtained at 30 min. This result was confirmed by its lower impedance values and higher current densities when compared to the 15′-film. Surface chemistry played a major role on the corrosion behavior of the sputtered films and can be tailored by the deposition time.

    Icon

  • IPEN-DOC 25128

    PESQUEIRA, E.I.O. ; MUSCI, C.S. ; ROSSI, J.L. . Influence of the geometric characteristics of the mini-implants on mechanicals properties using artificial bone similar to anterior, middle and posterior regions of the jaws. Materials Science Forum, v. 930, p. 276-282, 2018. DOI: 10.4028/www.scientific.net/MSF.930.276

    Abstract: The objective of this study was to identify the best torque of insertion and removal of mini-implants with a twin screw design (compact and self-drilling) into artificial bones with density and trabecular thickness, similar to anterior, middle and posterior regions of the jaws. Observation of the mini-implants surface using electron microscopy was performed before and after the tests. The torque values obtained during the insertion and removal was measured by digital torque wrench. The analyzed results led to the conclusion that the insertion and removal torques were larger with increase in bone density and cortical thickness. The design of the threads of the miniimplants influenced the insertion torque. Threads with smaller pitch increased the value of insertion torque. The anterior bone drilling installation reduces the insertion torque independent of bone density. Torque increased mainly by increasing the bone density and not necessarily with increased cortical thickness suggesting that the bone density of the trabecular bone must be considered in designing the installation of mini-implants.

    Icon

  • IPEN-DOC 25127

    ORTIZ, NILCE ; LIMA, GISELLE N.S. ; NICOLAU, THAMIRES S. ; REIS, ANNA C.S. . Solar/TiO2 photodecomposition and adsorption of tertiary antibiotics systems. International Journal of Latest Engineering and Management Research, v. 3, n. 6, p. 76-83, 2018.

    Abstract: The antibiotic residues are present usually in mixtures in soils and rivers sediment in the range of ng L-1 to μg L-1 around the world and cause, among many things, the proliferation of super-resistant bacteria. The study analyzes the efficiency of titanium dioxide (TiO2) and the solar photodecomposition of binary and tertiary systems of cephalexin, amoxicillin, and oxytetracicline from contaminated water discharges. The calculated kinetic constants of pseudo-first order, pseudo-second order and intraparticle diffusion confirm the better agreement with the pseudo-second-order. The isotherms parameters and constants of Langmuir, Freundlich, Redlich-Peterson (R-P) indicated the Langmuir and R-P isotherms have better correspondence, and the experimental results indicate 45% of removal percentage of antibiotics mixture in just 120 min of time stirring. The amoxicillin has the higher removal percentages followed by cephalexin and the lowest percentage was for oxytetraciclin. This behavior is explained by the chemical bond energy of the chemical structure, lower for amoxicillin increasing until the oxytetraccilin structure. The water treatment using Advanced Oxidative Processes - POA with TiO2 and solar radiation at different concentrations an mixtures of antibiotics followed by adsorption process rises as an efficient and ready to use water treatment to reach better water quality for reuse purposes.

    Icon

  • IPEN-DOC 25126

    OLIVEIRA, J.R.B.; FINOCCHIARO, P.; AGODI, C.; BOZTOSUN, I.; CAPPUZZELLO, F.; FARIA, P.N. de; GASQUES, L.; LINARES, R.; MEDINA, N.H.; MENDES, D.R.; MORALLES, M. ; SOLACKI, S.O.; ZAGATTO, V.A.B.; ALCANTARA-NUNEZ, J.A.; GONZALEZ-ALVAREZ, M.A.; AGUIAR, V.A.P.; ESCUDEIRO, R.; KURMAN, V.. New spectrometer projects for challenging particle-gamma measurements of nuclear reactions. Journal of Physics: Conference Series, v. 1056, 2018. DOI: 10.1088/1742-6596/1056/1/012040

    Abstract: Two new gamma spectrometer projects are under development, both with some challenging technical characteristics in common, one for the investigation of weakly bound nuclear beam reactions at near barrier energies, and the other for the measurement of double charge exchange reactions in the 15-70 MeV per nucleon range. The first one is being developed and tested at the IFUSP, and the other is going to be built and installed at the LNS, INFN, under the NUMEN collaboration. The main characteristics of the two projects are presented and discussed.

    Icon

  • IPEN-DOC 25125

    OLIVEIRA, JUSTINE P.R. ; MELENDEZ-ORTIZ, H.I.; BUCIO, EMILIO; ALVES, PATRICIA T.; LIMA, MAYARA I.S.; GOULART, LUIZ R.; MATHOR, MONICA B. ; VARCA, GUSTAVO H.C. ; LUGAO, ADEMAR B. . Current methods applied to biomaterials – characterization approaches, safety assessment and biological international standards. Current Topics in Medicinal Chemistry, v. 18, n. 4, p. 256-274, 2018. DOI: 10.2174/1568026618666180410151518

    Abstract: Safety and biocompatibility assessment of biomaterials are themes of constant concern as advanced materials enter the market as well as products manufactured by new techniques emerge. Within this context, this review provides an up-to-date approach on current methods for the characterization and safety assessment of biomaterials and biomedical devices from a physical-chemical to a biological perspective, including a description of the alternative methods in accordance with current and established international standards.

    Icon

  • IPEN-DOC 25124

    NASCIMENTO, C.R.; ASFORA, V.K.; GONCALVES, J.A.C. ; KHOURY, H.J.; BARROS, V.S.M.; KALIL, L.F.; BUENO, C.C. . The performance of a multi guard ring (MGR) diode for clinical electron beams dosimetry. Applied Radiation and Isotopes, v. 141, p. 112-117, 2018. DOI: 10.1016/j.apradiso.2018.07.002

    Abstract: The dosimetric response of a multi guard ring structure (MGR) diode has been studied with clinical electron beam energies from 5 MeV to 15 MeV. The results showed that the MGR dose response is linear in the range of 5–320 cGy and presents reproducibility with variation coefficients less than 0.4%. The field output factors measured with the MGR agreed within 2% with those measured with an ionization chamber. This study evidences that this diode can be used for clinical electron beam dosimetry.

    Icon

  • IPEN-DOC 25123

    NASCIMENTO, MAURICIO S.; FRANCO, ANTONIO T.R.; FRAJUCA, CARLOS; NAKAMOTO, FRANCISCO Y.; SANTOS, GIVANILDO A. dos; COUTO, ANTONIO A. . An experimental study of the solidification thermal parameters influence upon microstructure and mechanical properties of Al-Si-Cu alloys. Materials Research, v. 21, n. 5, 2018. DOI: 10.1590/1980-5373-MR-2017-0864

    Abstract: Metals solidification involves the transformation of the molten metal back into the solid state. Solidification structures impact heavily on the final product's characteristics. The microstructure effects on metallic alloys properties have been highlighted in various studies and particularly the dendrite arm spacing influence upon the mechanical properties such as tensile strength has been reported. In the present investigation, Al-10wt%Si-2wt%Cu and Al-10wt%Si-5wt%Cu alloys were directionally solidified upward under transient heat flow conditions. The experimental results include solidification thermal parameters such as tip growth rate and cooling rate, optical microscopy, volume fraction of the eutectic mixture, primary dendritic arm spacing and ultimate tensile strength. Experimental growth laws of primary dendrite arm spacing as a function of the solidification thermal parameters are proposed. The Hall-Petch mathematical expressions were used to correlate the ultimate tensile strength as a function of the primary dendritic arm spacing. It was found that the alloy with higher copper content had a more refined structure. More refined structures had higher ultimate tensile strength values.

    Icon

  • IPEN-DOC 25122

    NANDENHA, J. ; FONTES, E.H. ; PIASENTIN, R.M. ; FONSECA, F.C. ; NETO, A.O. . Direct oxidation of methane at low temperature using Pt/C, Pd/C, Pt/C-ATO and Pd/C-ATO electrocatalysts prepared by sodium borohydride reduction process. Journal of Fuel Chemistry and Technology, v. 46, n. 9, p. 1137-1145, 2018. DOI: 10.1016/S1872-5813(18)30046-X

    Abstract: The main objective of this paper was to characterize the voltammetric profiles of the Pt/C, Pt/C-ATO, Pd/C and Pd/C-ATO electrocatalysts and study their catalytic activities for methane oxidation in an acidic electrolyte at 25°C and in a direct methane proton exchange membrane fuel cell at 80°C. The electrocatalysts prepared also were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The diffractograms of the Pt/C and Pt/C-ATO electrocatalysts show four peaks associated with Pt face-centered cubic (fcc) structure, and the diffractograms of Pd/C and Pd/C-ATO show four peaks associated with Pd face-centered cubic (fcc) structure. For Pt/C-ATO and Pd/C-ATO, characteristic peaks of cassiterite (SnO2) phase are observed, which are associated with Sb-doped SnO2 (ATO) used as supports for electrocatalysts. Cyclic voltammograms (CV) of all electrocatalysts after adsorption of methane show that there is a current increase during the anodic scan. However, this effect is more pronounced for Pt/C-ATO and Pd/C-ATO. This process is related to the oxidation of the adsorbed species through the bifunctional mechanism, where ATO provides oxygenated species for the oxidation of CO or HCO intermediates adsorbed in Pt or Pd sites. From in situ ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) experiments for all electrocatalysts prepared the formation of HCO or CO intermediates are observed, which indicates the production of carbon dioxide. Polarization curves at 80°C in a direct methane fuel cell (DMEFC) show that Pd/C and Pt/C electroacatalysts have superior performance to Pd/C-ATO and Pt/C-ATO in methane oxidation.

    Icon

  • IPEN-DOC 25120

    MUTARELLI, RITA de C. ; LIMA, ANA C. de S. ; SABUNDJIAN, GAIANE . Comparative study of methodologies for measuring corporate social responsibility. International Journal of Development Research, v. 8, n. 6, p. 20894-20903, 2018.

    Abstract: The Corporate Social Responsibility (CSR) is a current issue increasingly present in the strategic planning of the companies. Although managers of public or private organizations have turned their attention to social and environmental issues in their strategic actions, measuring the social responsibility of a company is not an easy task. This paper aims to observe the eight most relevant methodologies of CSR measurement and establish a comparative analysis among them by considering the scope and feasibility of each methodology. The most relevant CSR methodologies were selected. The main characteristics of each of the eight tools were observed and compared. The results demonstrated that although most methodologies have strong measuring characteristics the Ethos Indicators consist of the most effective tool for measuring CSR mainly regarding the institutional issues

    Icon

  • IPEN-DOC 25119

    MURATA, H.M.; MORALLES, M. ; BONIFACIO, D.A.B.. Evaluation of digital methods for energy calculation and timing pick-off in positron emission tomography. Journal of Instrumentation, v. 13, n. P09024, 2018. DOI: 10.1088/1748-0221/13/09/P09024

    Abstract: Traditionally, pulse processing in Positron Emission Tomography (PET) has been based on analog or discrete circuits forming a decentralized processing system. However, there is a convergence for digital and integrated implementations due to the characteristics of the modern electronic devices which are real-time processing capable, such as Application-Specific Integrated Circuit (ASIC) and Field Programmable Gate Array (FPGA) with fast Analog to Digital Converters (ADC). However, FPGA can provide fast implementation at relatively low cost and also enables the development of sophisticated digital pulse processing algorithms to improve energy, position and time resolutions in PET systems. Our group has developed and evaluated one energy calculation and three timing pick-off methods for implementation onto an FPGA-based system. For a typical PET detector setup, our charge integration method presents energy resolution similar to previously designed PET detectors. The best performance for timing pick-off was achieved by the Initial Rise Interpolation (IRI) method, where a coincidence time resolution of around 440 ps is suitable for Time of Flight (TOF) PET. Future works include embedding the proposed algorithms in a FPGAbased data acquisition system under development by our group which will be employed in a PET prototype.

    Icon

  • IPEN-DOC 25118

    MUCSI, C.S. ; REIS, L.A.M. dos ; GOMES, M.P. ; PEREIRA, L.A.T. ; ROSSI, J.L. . Study on the viability of the recycling by electric arc melting of zirconium alloys scraps aiming the scalability of the process. Materials Science Forum, v. 930, p. 495-500, 2018. DOI: 10.4028/www.scientific.net/MSF.930.495

    Abstract: Turning chips of zirconium alloys are produced in large quantities during the machining of alloy rods for the fabrication of the end plugs for the Pressurized Water Reactor (PWR) fuel elements parts of Angra II nuclear reactor (Brazil – Rio de Janeiro). This paper presents a study on the search for an efficient way for the cleaning, quality control and Vacuum Arc Remelting (VAR) of pressed zirconium alloys chips to produce a material viable to be used in the production of the fuel rod end plugs. The process starts with cutting oil clean out. The first step in this process consists in soaking a bunch of chips in clean water, to remove soluble cutting oils, followed by an alkaline degreasing bath and a wash with a high-pressure flow of water. Drying is performed by a flux of warm air. The oil free chips are then subjected to a magnet in order to detect and collect any magnetic material, essentially ferrous, that may be present in the original chips. Samples of the material are collected and then melted in a small non consumable electrode vacuum arc furnace for evaluation by Energy Dispersive X-ray Fluorescence Spectrometry (EDXRFS) in order to define the quality of the chips. The next step consists in the 15 ton hydraulic pressing the chips in a die with 40 mm square section and 500 mm long, producing an electrode with 20% of the Zircaloy bulk density. The electrode was finally melted in a laboratory scale modified VAR furnace located at the CCTM–IPEN, producing 0.8 kg ingots. The authors conclude that the samples obtained from the fuel element industry can be melting in a VAR furnace, modified to accommodate low density electrodes, allowing a reduction up to 40 times the original storage volume, however, it is necessary to remelt the ingots to correct their composition in order to recycle the original zirconium alloys chips. in a process to reduce volume and allow the reutilization of valuable Zircaloy scraps.

    Icon

  • IPEN-DOC 25117

    MUCCILLO, R. ; ESPOSITO, V.; FLORIO, D.Z. de; MUCCILLO, E.N.S. . Electric field-assisted pressureless sintering gadolinium-, yttrium- and samarium-doped barium cerate. Scripta Materialia, v. 156, p. 6-9, 2018. DOI: 10.1016/j.scriptamat.2018.07.005

    Abstract: Gadolinium-, yttrium- and samarium-doped barium cerate compounds were sintered either conventionally at 1500 °C or applying an electric field at 1200 °C. The combined results of dilatometry and impedance spectroscopy measurements in electric field-assisted sintered specimens show substantial improvement of the electrical conductivity. Improved grain-to-grain contact and the thermal removal of depleted chemical species due to Joule heating at the space charge region are proposed as the main mechanisms for the increase of both the grain boundary and the bulk electrical conductivities, respectively.

    Icon

  • IPEN-DOC 25116

    MOREIRA, TIANA C.L.; AMATO-LOURENCO, LUIS F.; SILVA, GISELA T. da; ANDRE, CARMEN D.S. de; ANDRE, PAULO A. de; BARROZO, LIGIA V.; SINGER, JULIO M.; SALDIVA, PAULO H.N.; SAIKI, MITIKO ; LOCOSSELLI, GIULIANO M.. The use of tree barks to monitor traffic related air pollution: a case study in São Paulo–Brazil. Frontiers in Environmental Science, v. 6, n. 72, p. 1-12, 2018. DOI: 10.3389/fenvs.2018.00072

    Abstract: The analysis of chemical elements in the barks of trees is an alternative procedure to access spatial heterogeneity of traffic related air pollution. However, the role of tree species in the characterization of the variability of airborne pollution is poorly known. We present an observational study conducted in São Paulo, Brazil, based on the analysis of 498 trees from three common species: Tipuana tipu, Poincianella pluviosa, and Ligustrum sp. We considered ANCOVA models to compare the concentrations of Al, Fe, Zn, Cu, Mn, Ba, and S in the bark (periderm) of trees located close to streets with different levels of traffic intensity controlling for the extension of nearby green areas. The expected trend of increasing elemental concentration in the bark of trees located near streets with greater traffic intensity or close to smaller green areas was only fully evidenced by T. tipu. For instance, the concentrations of Zn, Fe, Al, and Ba increase by 200, 350, 230, and 280% respectively, for trees of this species located near arterial streets when compared to those observed near local streets. On the other hand, the concentrations of Zn, Fe, Al, and Ba are reduced by 41, 45, 50, and 30%, respectively, for trees located near green areas. For P. pluviosa, the capacity to suggest an association between the tree bark concentration of chemical elements with increasing levels of air pollution and presence of green areas was only fully observed for Zn and Cu. For Ligustrum sp., weaker and sometimes non-expected associations between bark concentrations of the chemical elements and either street classification or green area extension were observed. Our results indicate that the choice of species is a key element in the use of tree barks as a biomonitoring tool in urban landscapes. Species like T. tipu, with rough and highly porous bark, are the most appropriate for such purpose.

    Icon

  • IPEN-DOC 25115

    MOREIRA, GREGORI de A. ; GUERRERO-RASCADO, JUAN L.; BRAVO-ARANDA, JUAN A.; BENAVENT-OLTRA, JOSE A.; ORTIZ-AMEZCUA, PABLO; ROMAN, ROBERTO; BEDOYA-VELASQUEZ, ANDRES E.; LANDULFO, EDUARDO ; ALADOS-ARBOLEDAS, LUCAS. Study of the planetary boundary layer by microwave radiometer, elastic lidar and Doppler lidar estimations in Southern Iberian Peninsula. Atmospheric Research, v. 213, p. 185-195, 2018. DOI: 10.1016/j.atmosres.2018.06.007

    Abstract: The Planetary Boundary Layer (PBL) is a relevant part of the atmosphere with a variable extension that clearly plays an important role in fields like air quality or weather forecasting. Passive and active remote sensing systems have been widely applied to analyze PBL characteristics. The combination of different remote sensing techniques allows obtaining a complete picture on the PBL dynamic. In this study, we analyze the PBL using microwave radiometer, elastic lidar and Doppler lidar data. We use co-located data simultaneously gathered in the framework of SLOPE-I (Sierra Nevada Lidar aerOsol Profiling Experiment) campaign at Granada (Spain) during a 90- day period in summer 2016. Firstly, the PBL height (PBLH) obtained from microwave radiometer data is validated against PBLH provided by analyzing co-located radiosondes, showing a good agreement. In a second stage, active remote sensing systems are used for deriving the PBLH. Thus, an extended Kalman filter method is applied to data obtained by the elastic lidar while the vertical wind speed variance method is applied to the Doppler lidar. PBLH′s derived by these approaches are compared to PBLH retrieved by the microwave radiometer. The results show a good agreement among these retrievals based on active remote sensing in most of the cases, although some discrepancies appear in instances of intense PBL changes (either growth and/or decrease).

    Icon

  • IPEN-DOC 25114

    MATOS, BRUNO R. ; POLITANO, RODOLFO ; REY, JOSE F.Q.; HERMIDA-MERINO, DANIEL; SCHADE, ULRICH; PUSKAR, LJILJANA; FONSECA, FABIO C. . Interplay of alpha/beta-relaxation dynamics and the shape of ionomer building blocks. Scientific Reports, v. 8, n. 13441, 2018. DOI: 10.1038/s41598-018-31368-8

    Abstract: The relation between the alpha/beta relaxations and the shape of the building blocks of ionomer materials is a key factor for programming an important temperature-dependent property: the memory of shape. However, the morphology of ionomers is indirectly obtained via modeling of small angle X-ray scattering (SAXS) data owing to the hardly accessible image characterization of the nanometric building blocks-micelle-like cylindrical polymeric aggregates (radius similar to 2-6 nm and length >100 nm). Herein, broadband dielectric spectroscopy (BDS) measurements, free from electrode polarization effects, allowed identifying the time and temperature dependence of the polarization of different length scales of the ionomer matrix, and more importantly, by directly providing the aspect ratio of the radius and length of the polymeric aggregates for each desired temperature. This finding is essential for controlling the shape of ionomer based functional products under several stimuli conditions, thereby advancing remarkable applications, such as four dimensional (4D) printing.

    Icon

  • IPEN-DOC 25113

    MARTINS, JOAO F.T. ; SANTOS, ROBINSON A. dos ; FERRAZ, CAUE de M. ; OLIVEIRA, RENE R. ; FIEDERLE, MICHAEL; AMADEU, RAFAEL de A. ; SANTOS, RODRIGO S. dos ; SILVA, THIAGO L.B. da ; HAMADA, MARGARIDA M. . Optimization of the HgI2 Crystal preparation for application as a radiation semiconductor detector. Studies in Engineering and Technology, v. 5, n. 1, p. 76-88, 2018. DOI: 10.11114/set.v5i1.3149

    Abstract: The effect of HgI2 crystal encapsulation using different polymer resins, with the intent of avoiding the oxidation of the crystal surface, was evaluated in this work. The crystal was purified and grown by the physical vapor transport (PVT) technique modified. Systematic measurements were carried out for evaluating the stoichiometry, structure orientation, surface morphology and impurity of the crystal grown. The purer region of the crystal grown was selected to be prepared as a radiation detector, applying water-based conductive ink contacts and copper wire on the crystal surfaces. After that, the crystal was encapsulated with a polymeric resin which insulates atmospheric gases, aiming to improve the stability of the HgI2 detector. Four resins were used for crystal encapslation and the performance of the detector depended on the composition of the resins used. Among the four resins studied to evaluate the influence of encapsulation on the performance of crystals, as a radiation detector, the best result of resistivity and energy spectrum was obtained for the resin #3 (50% - 100% of Methylacetate and 5% - 10% of n-butylacetate). The encapsulation of crystals with polymer resins, performed with the intent of avoiding the oxidation of the crystal surface, did not compromise the measurements and were fully capable of detecting the presence of gamma radiation. The stability of the encapsulated HgI2 crystal detector was of up to 78 hs, while the stability found for HgI2 detector no encapsulated was in order 3 ~4 hs.

    Icon

  • IPEN-DOC 25112

    MARIANO, DOUGLAS O.C.; MESSIAS, MARCELA Di G. ; PREZOTTO-NETO, JOSE P. ; SPENCER, PATRICK J. ; PIMENTA, DANIEL C.. Biochemical analyses of proteins from duttaphrynus melanostictus (Bufo melanostictus) skin secretion: soluble protein retrieval from a viscous matrix by ion-exchange batch sample preparation. Protein Journal, v. 37, n. 4, p. 380-389, 2018. DOI: 10.1007/s10930-018-9780-z

    Abstract: A crucial step in scientific analysis can be sample preparation, and its importance increases in the same rate as the sensitivity of the following employed/desired analytical technique does. The need to analyze complex, viscous matrices is not new, and diverse approaches have been employed, with different success rates depending on the intended molecules. Solid-phase extraction, for example, has been successfully used in sample preparation for organic molecules and peptides. However, due to the usual methodological conditions, biologically active proteins are not successfully retrieved by this technique, resulting in a low rate of protein identification reported for the viscous amphibian skin secretion. Here we describe an ion-exchange batch processing sample preparation technique that allows viscous or adhesive materials (as some amphibian skin secretions) to be further processed by classical liquid chromatography approaches. According to our protocol, samples were allowed to equilibrate with a specific resin that was washed with appropriated buffers in order to yield the soluble protein fraction. In order to show the efficiency of our methodology, we have compared our results to classically prepared skin secretion, i.e., by means of filtration and centrifugation. After batch sample preparation, we were able to obtain reproductive resolved protein chromatographic profiles, as revealed by SDS-PAGE, and retrieve some biological activities, namely, hydrolases belonging to serine peptidase family. Not only that, but also the unbound fraction was rich in low molecular mass molecules, such as alkaloids and steroids, making this sample preparation technique also suitable for the enrichment of such molecules.

    Icon

  • IPEN-DOC 25110

    UCO, DAYANE P.; LEITE-SILVA, VANIA R.; SILVA, HERON D.T.; DUQUE, MARCELO D.; GRICE, JEFFREY; MATHOR, MONICA B. ; ANDREO-FILHO, NEWTON; LOPES, PATRICIA S.. UVA and UVB formulation phototoxicity in a three-dimensional human skin model: photodegradation effect. Toxicology in Vitro, v. 53, p. 37-44, 2018. DOI: 10.1016/j.tiv.2018.07.009

    Abstract: In vitro three-dimensional human skin models are an innovative alternative to evaluate cytotoxicity and phototoxicity in the cosmetic industry. The aim of this study was to use a skin model to evaluate the potential toxicity of sunscreen formulations with or without exposure to UV radiation. In addition, the toxicity of these formulations was evaluated after exposure to photodegradation. The results showed toxicity with all formulations/conditions tested, including the control formulation, compared to PBS. Cell viability of photodegraded formulations - prior to the phototoxicity radiation process - was higher, indicating that some formulation components were degraded into products with reduced toxicity. The results also indicated that avobenzone was more unstable/toxic than octyl p-methoxycinnamate under the same test conditions. The sunscreens and their formulations were shown to be toxic to skin model cells to some extent, even when not exposed to UV irradiation; however the biological role of this toxicity is unclear. This result shows the importance of testing sunscreen formulations in real in-use conditions. Finally, since we used an in vitro assay based on a human cell model, this non-invasive technique represents a suitable alternative to animal models for phototoxicity tests in general and could have application in screening new sunscreen products.

    Icon

View more

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.

Exemplo:

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, bibl@ipen.br .

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).

ATENÇÃO!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

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.