Abstract: OBJETIVOS – O fluoreto estanoso, princípio ativo do reagente liofilizado TIN-TEC, também atua como agente redutor do Tecnécio-99m (99mTc) que é o radioisótopo mais utilizado na medicina nuclear para obtenção de imagens para diagnóstico por SPECT de várias enfermidades. O 99mTc apresenta propriedades físicas ideais e pode variar oestado de oxidação de -1 a +7, quando reage com uma variedade de compostos orgânicos e inorgânicos na presença de Sn+2. Entretanto, Sn+2 é instável e pode ser oxidado a Sn+4 na presença de oxigênio e em soluções aquosas pode precipitar como um fluoreto básico insolúvel. A utilização de método analítico não descrito em compêndio oficial reconhecido pela ANVISA requer a realização de uma validação analítica. O objetivo deste trabalho foi validar o método utilizado na quantificação de estanho total em amostra de reagente liofilizado TIN-TEC, usando espectroscopia de emissão óptica com plasma indutivamente acoplado (ICP-OES) como método alternativo inovador, uma vez que a técnica está sendo introduzida para a análise de estanho, em substituição ao método espectrofotométrico no visível com ditiol, descrito na farmacopeia europeia. MATERIAIS E MÉTODOS – As análises foram realizadas em um ICP-OES Vista MPX Agilent equipado com nebulizador de vidro Seaspray, utilizando argônio como plasma e gás auxiliar. As amostras foram introduzidas direta e sequencialmente no plasma, com o auxílio da bomba peristáltica, utilizando-se as linhas de emissão 189,927 e 242,950 nm. A metodologia foi validada contemplando os ensaios de seletividade, linearidade/faixa de trabalho, repetibilidade, precisão intermediária e robustez. A concentração de Sn foi relacionada à quantidade de fluoreto estanoso e o limite de aceitação foi estabelecido entre 90-110 % para a quantidade presente na formulação do RL. RESULTADOS – A curva de calibração apresentou-se linear na faixa de 1,52 a 2,27 µg mL–1, obtendo-se coeficiente de correlação da curva de calibração de 0,995, superior a 0,99 que é o requisito de aceitação para linearidade de métodos analíticos. Todos os outros ensaios obedeceram aos critérios de aceitação com valores de massa de estanho compreendidas entre 90-110 % e com desvios padrão relativo (DPR)< 5%. CONCLUSÕES – O método analítico proposto para determinação de Sn total no reagente liofilizado TIN-TEC por ICP-OES foi validado e os resultados mostraram que a técnica ICP-OES apresenta vantagens sobre o método espectrofotométrico para estanho descrito na Farmacopeia Europeia como método limite.

SANTOS, JOEL M. dos; MATSUDA, MARGARETH M.N.; ARAUJO, ELAINE B. de. Validação de método para determinação de estanho total por ICP-OES em reagente liofilizado TIN-TEC. In: CONGRESSO BRASILEIRO DE MEDICINA NUCLEAR, 37., 21-23 de setembro, 2023, Porto de Galinhas, PE. Resumo... São Paulo, SP: Sociedade Brasileira de Medicina Nuclear - SBMN, 2023. Disponível em: http://repositorio.ipen.br/handle/123456789/34443. Acesso em: $DATA.

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Abstract: The naturally occurring radionuclides 7Be and 210Pb are produced in the atmosphere and used as tracers of a wide variety of processes that occur in the Earth's atmosphere and surface. The cosmogenic radionuclide 7Be (T1/2 = 53.3 d), is produced in the upper atmosphere by cosmic ray spallation of oxygen and nitrogen; 210Pb (T1/2 = 22.3 y), a natural radionuclide from 238U series can be found in the atmosphere, as a product of 222Rn decay that emanates from the ground. Both natural radionuclides can be used as tracers for heavy metals and pollutants in the environment, tracer of soil erosion, transport processes in watershed and sedimentation in lakes, among other examples. The activity concentration results of these radionuclides in rainfall, when combined with meteorological information, help to understand how aerosol particles are transported in the air and removed from the atmosphere by the action of rainfall. The objectives of this work were to determine the activity concentrations of the natural radionuclides 7Be and 210Pb in rainfall samples over a period of two years, from January 2021 to December 2022, in each rainy event that occurred on the IPEN campus, located in the city of São Paulo, Brazil. Be-7 activity concentrations were measured by non-destructive gamma-ray spectrometry using a coaxial Be-layer HPGe detector with 25% relative efficiency and associated electronic devices and live counting time varying from 80,000 s to 300,000 s; 210Pb activity concentrations were measured by gross beta counting in a low background gas flow proportional detector, after radiochemistry procedure. The annual rainfall indices for 2021 and 2022 were 1093 mm and 1391 mm, respectively. Activity concentrations for 7Be ranged from 0.459 ± 0.038 Bq L-1 to 8.96 ± 0.57 Bq L-1 and for 210Pb from 0.015 ± 0.001 to 0.98 ± 0.01 Bq L-1 in the studied period. The results obtained of 7Be and 210Pb in rainfall were correlated to seasons, precipitation, temperature, and sunspot number for 7Be. The higher values obtained for the concentrations were in winter and spring time presenting good correlations with the amount of precipitation and sunspot number and a clear seasonal variation.

CASTRO, J.O.; DOMINGOS, R.M.; DAMATTO, S.R.; RODRIGUES, C.E.C.; ISIKI, V.L.; NETO, J.O.A. Two years of continuous monitoring of 7Be and 210Pb in rainfall collected at the IPEN campus, São Paulo, Brazil. In: INTERNATIONAL CONFERENCE ON ENVIRONMENTAL RADIOACTIVITY, 7th, September 17-22, 2023, Seville, Spain. Abstract... Seville, Spain: Universidad de Sevilla, 2023. p. 311-311. Disponível em: http://repositorio.ipen.br/handle/123456789/34455. Acesso em: $DATA.

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Abstract: Recent studies have proposed the investigation of alexandrite mineral (BeAl2O4:Cr3+) as a potential luminescent dosimeter. Despite this, in-depth studies of defects and luminescent centers in alexandrite were not investigated. It is proposed to characterize the thermoluminescence (TL) emission spectra, fluorescence (FL) and electron paramagnetic resonance (EPR) of alexandrite. TL dosimeters, when stimulated by thermal energy, emit light proportional to the dose of ionizing radiation previously absorbed. The emitted wavelength can be measured through thermoluminescence emission spectra. On the other hand, EPR and FL provides additional information about mineral structure, enabling the study of the effects of ionizing radiation on the sample. For TL, the samples were irradiated with Xrays and measured by Lumi22 homemade system. EPR measurements were carried out using a Bruker EMXplus spectrometer operating in the X-band at room temperature, 2 mW microwave power, 100 kHz modulation frequency and 0.25 mT modulation amplitude. The FL spectra were measured using the Duetta spectrofluorometer, with a 75 W xenon arc lamp included. The data was collected by scanning excitation wavelengths in 360-480 nm and recording emission in the wavelength range of 670-740 nm. Preliminary results indicate that the TL emission spectra presented two peaks, at ~80°C and ~175°C, with emission centered between 600 nm – 700 nm, related to Fe3+ and Cr3+, also detected by EPR. The FL spectra showed two signals: an emission centered at 680 nm (Cr3+ in inversion center), and at 700 nm (Cr3+ in mirror symmetry). The results of all techniques used in this work suggest that emissions are correlated to Cr3+ and Fe3+ ions.

SILVA, ALEXIA O.; NUNES, MATHEUS C. dos S.; YOSHIMURA, ELISABETH M.; RODRIGUES JUNIOR, ORLANDO; TRINDADE, NEILO M. Thermoluminescence, fluorescence and electron paramagnetic resonance of natural alexandrite. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1016-1016. Disponível em: http://repositorio.ipen.br/handle/123456789/34562. Acesso em: $DATA.

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Abstract: In the last decades, the demand for new materials to be used in electronic devices has increased. Among the materials that can be used in transparent conductive films (TCFs), are the silver nanowires (AgNWs). This class of material, when supported in glass or PET, e.g., has good conductivity, thermal and mechanical properties and also high transparency. In this work, the AgNWs were synthesized using the polyol method assisted by a salt and the influence of molecular weight of the capping agent polyvinylpyrrolidone (PVP) in the morphology and structure of Ag crystals was investigated. Different molecular weight of PVP (40 K, 120 K, 360 K and 1300 K MW) was used in the synthesis. The surface morphology of the products was observed by scanning electron microscopy and atomic force microscopy. The phase composition and structure were analyzed by X-ray diffraction (XRD) and the XRD patterns diffraction peaks correspond with the face-centered-cubic (fcc) crystalline phase of silver. Transmission electron microscopy was used to analyze the crystal structure, and UV-visible spectroscopy was used to follow the formation of Ag structures. The results indicate that PVP and its chain length have an important role in the formation of silver nanocrystals due to the adsorption and steric effects [1] and as high is the molecular weight of PVP, longer and thinner are the AgNWs as observed by other authors [2]. Different morphologies were obtained when changing the size of PVP chain. For smaller MW of PVP, particles and short wires were formed. Increasing the MW, nanorods and pyramidal particles were formed, and finally, forming nanowires when using the highest MW PVP of the experiments.Improving the aspect ratio of silver nanowires is important to construct TCFs, since the conductivity and transparency properties are improved when they are thinner and longer.

SILVA, BARBARA P.G.; OTUBO, LARISSA. The influence of PVP molecular weight in the synthesis of silver nanowires using a salt-assisted polyol method. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 877-877. Disponível em: http://repositorio.ipen.br/handle/123456789/34561. Acesso em: $DATA.

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Abstract: For more than 50 years, the Energy and Nuclear Research Institute IPEN, has been offering solutions to Brazil through nuclear technology. Thus, one of the main areas where IPEN has contributed assertively is medicine. Reaching the level of 32 radiopharmaceuticals and radioactive sources intended both for therapy and for the diagnosis of several pathologies, including cancer, which are obtained with the help of the two nuclear reactors and two cyclotrons present in the institution. The Institute has a team for the development, production and distribution of radioactive sources for brachytherapy, such as 192 Ir wires and 125 I seeds. Brachytherapy is a cancer treatment technique where the radioactive source is placed close to or in contact with the lesion. The great advantage of the technique is to save healthy tissues. Currently, we are working on obtaining nanometric materials that can be applied in the emerging nano brachytherapy, because of its properties and characteristics at the nanometric level, gold has been the subject of studies and tests. Elemental Au gold can be activated 198 Au inside a nuclear reactor, and has β- decay and a half-life of 2.7 days, which makes it ideal for short-term irradiations. In addition, gold in the form of nanoparticles has a completely different chemistry, with gold nanoparticles (AuNPs) being easily functionalized by a large part of molecular and polymeric binders, which may present favorable characteristics for the studies, and together with AuNPs they are able to work synergistically to achieve greater efficiencies. Currently, AuNPs have been successfully functionalized with gum arabic (GA), a coating widely used in the cosmetic and food industry, which is low cost and along with nanoparticles has shown biocompatibility with different cell groups and has been shown to be very stable over time. The project includes studies regarding the synthesis of nanoparticles, coating, cytotoxicity of AuNPs in vitro "cold" (non-radioactive) and the development of activation protocols in the nuclear reactor. In the next phase, after activation, in the reactor, "hot" tests will be performed in vitro and in vivo.

ROSERO, WILMMER A.A.; BARBEZAN, ANGELICA B.; ROSTELATO, MARIA E.C.M.; SOUZA, CARLA D. de; NOGUEIRA, BEATRIZ R.; ZEITUNI, CARLOS A. Synthesis, activation and application testing of gold nanoparticles for nanobrachytherapy. In: INTERNATIONAL SYMPOSIUM ON TRENDS IN RADIOPHARMACEUTICALS, April 17-21, 2023, Vienna, Austria. Abstract... Vienna, Austria: International Atomic Energy Agency - IAEA, 2023. p. 24-24. Disponível em: http://repositorio.ipen.br/handle/123456789/34543. Acesso em: $DATA.

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Abstract: The properties of welded joints subjected to cyclic loading is an important subject in several áreas[1]. In this scenario, aiming to study this subject, welded joints made of ASTM A 516 GR 70 steel plates, with a thickness of 30.5 mm, welded by the MAG – Metal Active Gas process (20% CO2) with the use of a K-bevel were analyzed. to allow full penetration due to the high thickness [2]. The joints were manufactured with seven welding passes on each side of the chamfer. After welding, one set was subjected to a repair pass, for remelting the surface of the bead using the TIG (Tungsten Inert Gas) process, while another set was subjected to two repair passes. This study aimed to analyze aspects of welded and repaired joints: dimensions (height and width) of the bead, behavior of the residual stress profile measured by X-ray diffraction, Vickers microhardness profile and fatigue crack nucleation with based on ASTM E466 and E606 standards. The results indicated that the greater number of repair passes decreased the compressive residual stress values in the transverse and longitudinal directions, from -350 MPa to 50 MPa. There was greater uniformity in hardness Vickers values (value between 200 and 210 HV) with the use of cord repairs. It was observed that the fracture toughness presented values of 1500 J/mm (without repair) and 900 J/mm (one pass and two repair passes), lower than that found in the material without welding (3500 J/mm). Therefore, as the repair passes were performed, the residual stresses in the weld bead tended to positive values, the hardness tended to stabilize with values of 200 HV due to the increase in the number of repair passes and the fracture toughness decreased in the welded material when compared to the values of the non-welded material. There was no significant difference in fracture toughness between repair passes.

BARROS, REGIS de M.C. de; NEVES, MAURICIO. Study of residual stresses and fracture toughness in welded and repaired joints using A516 Gr70 steel. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 1168-1168. Disponível em: http://repositorio.ipen.br/handle/123456789/34566. Acesso em: $DATA.

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