Brazilian Journal of Radiation Sciences (BJRS)
Brazilian Journal of Radiation Sciences - BJRS ISSN 2319-0612 Una forma de impactar la cultura de seguridad y protección radiológica es establecer procesos de comunicación adecuados entre todos los actores involucrados en las aplicaciones de las radiaciones y en la protección radiológica. En este contexto, la BJRS como revista de acceso abierto, mantenida por la Sociedad Brasileña de Protección Radiológica - SBPR, sociedad asociada de la Asociación Internacional de Protección Radiológica (IRPA), tiene como objetivo difundir artículos científicos sobre las principales disciplinas de las ciencias de la radiación, entre ellas: • Efectos biológicos y en la salud de la radiación, • Protección radiológica de pacientes, trabajadores y miembros del público, • Mediciones de Radiación y Dosimetría, • Recomendaciones y Normas Internacionales, • Protección del ambiente, • Educación y entrenamiento, • Tecnología y Desarrollo, • Comunicación con la Sociedad, • Compromiso y Participación de las Partes Interesadas, • Cultura de Seguridad y Percepción de Riesgo, • Preparación y respuesta ante emergencias, • Gestión de Residuos Radiactivos, • Transporte Seguro de Materiales Radiactivos, • Seguridad Nuclear, Salvaguardias y Seguridad de los Materiales Radiactivos, • Derecho Nuclear, • Tecnología de Reactores Nucleares: nuevos conceptos, • Ciclo del Combustible Nuclear.
Sociedade Brasileira de Proteção Radiológica
Licencia: los artículos de BJRS tienen una licencia internacional Creative Commons Attribution 4.0, que permite el uso, el intercambio, la adaptación, la distribución y la reproducción en cualquier medio o formato, siempre que se otorgue el crédito correspondiente al autor o autores originales y a la fuente, proporcione un enlace a la licencia Creative Commons e indique si se realizaron cambios. Las imágenes u otros materiales de terceros en el artículo están incluidos en la licencia Creative Commons del artículo, a menos que se indique lo contrario en una línea de crédito al material. Si el material no está incluido en la licencia Creative Commons del artículo y su uso previsto no está permitido por la regulación legal o excede el uso permitido, el autor deberá obtener el permiso directamente del titular de los derechos de autor. Para ver una copia de esta licencia, visite http://creativecommons.org/licenses/by/4.0/
Study for the Development of a Biosensor Aimed at the Interaction-Response of Chemical War Agents and Ionizing Radiation
It has long been known that the nuclear sector is a potential branch capable of solving major obstacles relevant to modern society with regard to energy demands. The technology in this sphere is associated with various possibilities, including areas that require multidisciplinary expertise for their respective advancements, such as medical sciences, security and defense, national autonomy and sovereignty, energy generation, food technology, among others. With the development of nanostructured technologies, highly sensitive, accessible, and easy to handle, it is possible to introduce new alternatives to reduce the “gap” between these possibilities within the sector, making the nuclear area more visible to new researchers due to the potential for new research to be developed. With the prospect of innovation for the sector and with increasing technological input, a special look at instrumental and measurement issues is necessary, since it is also necessary to ensure the quality of nuclear technology for the development of any system focused on this theme. This research presents a combination of different areas, highlighting the multidisciplinarity of construction, aiming to obtain the necessary support for the creation of a device capable of interacting with systems that represent chemical and radiological-nuclear threats. As it is a biosensor, it presents a biological interface sensitive to chemical warfare agents (organophosphates), neurotoxins and undergoes a process analogous to radiolysis, it is the means by which it is possible to associate electronics to the system, being capable of transducing information from one form of energy to another, making it possible to quantify and obtain relevant and proportional information about the exposure of this system created. For the in silico study carried out, the energy fluctuations for both the chemical simulations and the MCNP simulations were guiding the verification process, since the lower the energy value, the stronger the chemical interaction between ligands and enzymes.
The Meeting on Nuclear Applications (ENAN)
Derechos de autor 2025 João Nilton da Conceição Bandeira, Fabiane Modenese Garbim, Joyce Sobreiro Francisco Diz De Almeida, Álvaro José Boareto Mendes, Fernando Manuel Araújo Moreira https://creativecommons.org/licenses/by/4.0
Evaluation of the antioxidant, cytotoxic and radioprotective potencial of the lectin WSMoL from Moringa oleífera Lam. seeds
WSMoL (water-soluble lectin from the seeds of Moringa oleifera Lam.) is widely known for its biological properties, especially for its inflammatory, immunomodulatory and antitumor activity and is a promising candidate for a radioprotector of natural origin. Aim of the study: This study aimed to evaluate the antioxidant and cytotoxic potential and the radioprotective effect of WSMoL in human lymphocyte culture (PBMC). The concentrations analyzed were 850, 425, 212.5, 106.25 and 53.12µg/mL. Materials and methods: Antioxidant activity was tested using the DPPH and ABTS assays. Cell viability and cytotoxicity were assessed using the MTT assay on PBMC lymphocytes. Radioprotection was verified by the Alkaline Comet and Micronucleus with Blockage of Cell Cytokinesis assays after exposure to Cobalt-60 gamma radiation. Results: In the DPPH test, WSMoL was unable to capture the radical. In the ABTS test, the inhibition index (I%) was ≤10% and the IC50 was 71.42 g/L. The MTT test showed that the lectin was not cytotoxic and cell viability was over 79%, with a maximum (≤125%) at a concentration of 53.12 µg/mL. In the Alkaline Comet test, the Damage Index (DI) observed was high at concentrations of 850 and 53.12 µg/mL (≥170 ± 30). The Damage Frequency (y) observed through the Micronucleus assay was 0.260 for the two concentrations analyzed, similar to the y of the irradiated control group. Conclusion: WSMoL did not show significant antioxidant activity in the DPPH and ABTS tests. The lectin did not show a cytotoxic profile, and its use at a concentration of 53.12µg/mL is recommended. WSMoL showed no radioprotective capacity after exposure to gamma radiation at a dose of 2.5Gy.
Derechos de autor 2025 Osana Diniz Ferreira, Andreza Lima Lourenço da Silva, Karine Lafaiete De Carvalho, Thaynara Maria Arantes, Vinícius Henrique Teixeira Morais, Dewson Rocha Dewson Rocha Pereira, Thiago Henrique Napoleão, Mércia Liane de Oliveira, Ana Maria Mendonça de Albuquerque Melo https://creativecommons.org/licenses/by/4.0
Tissue Reactions (Deterministic Effects) in Diagnostic and Interventional Radiology: An Integrative Review of Recent Literature
Ninety-eight percent of the global average individual dose delivered by artificial sources of ionizing radiation results from their use in medical applications, especially for diagnostic and interventional purposes. Although the benefits of radiation in medicine are widely recognized, exposure to this agent can cause harmful effects on the health of exposed individuals. Radiation applications for diagnostic purposes are generally associated with low doses, but interventional procedures may involve much higher doses. In the 2000s and 2010s, several publications described tissue reactions in patients and professionals exposed during interventional radiological procedures. This work aimed to review the literature on the most recent reports (last decade) on the occurrence of tissue reactions after diagnostic or interventional radiological procedures. The PubMed search tool was used to search and select publications on the topic. Although 826 articles were initially selected, only 5 presented relevant content for this review. The low number of articles in the final selection may be a result of the methodology we used or an actual reduction in the number of individuals presenting these effects in more recent years, due to the growing concerns about radiological protection in these practices. Among the articles analyzed, there were reports of skin lesions, as well as thinning or hair loss in patients exposed to doses (cumulative air kerma at the reference point) above 3.5 Gy. However, these reactions are rare and do not appear in most patients, even among those who received higher doses. An increased frequency of lens opacities (cataracts) has also been reported in occupationally exposed professionals. An adequate assessment of the occurrence of these effects is essential to try to understand their causes and minimize the frequency or consequences of their occurrence. Carrying out research like this can help with this task.
Derechos de autor 2025 Laisa Neves, Lucía Canevaro Lucía Viviana Canevaro, Ana Dovales Ana Cristina Murta Dovales https://creativecommons.org/licenses/by/4.0
ApplyApplying Deep Learning in gamma-spectroscopy for radionuclide identificationng Deep-learning in gamma-spectroscopy for radionuclide identification
This study presents the results of using a Deep Convolutional Neural Network model on gamma spectrum classification for radioactive waste management. The approach uses a modified version of the VGG-19 architecture, originally developed for image recognition with 1000 mutually exclusive classes. The modified VGG-19 architecture uses a gamma spectrum as input and classifies, on a nonexclusive basis, ten classes representing the ten most common radionuclides at IPEN's Radioactive Waste Management Department (Am-241, Ba-133, Cd-109, Co-57, Co-60, Cs-137, Eu-152, Mn-54, Na-22, Pb-210). Gamma spectra were generated using Monte Carlo simulations created with PENELOPE/PenEasy, simulating an HPGe detector with sources inside a steel drum filled with paper, representing the common content of the drums managed at IPEN's Radioactive Waste Management Department. The data set was augmented by mixing these simulated spectra into new spectra containing up to four radionuclides. Several distances from the detector to the drum (41 cm, 46 cm, 51 cm, and 56 cm) were used to create a representative data set. The data from 56 cm (originally 150 spectra after the argumentation process, 375 spectra) was used for validation. After 250 training epochs, the model achieved consistent performance in the training set, demonstrating the efficiency of the method.
Derechos de autor 2025 André Gomes Lamas Otero, Ademar José Potiens Júnior, Julio Takehiro Marumo https://creativecommons.org/licenses/by/4.0
Human biomonitoring in residents of a NORM area using the comet assay, Pernambuco-Brazil
Geological research has found areas of uraniferous phosphorite in northeastern Brazil. This region is located along the coast of the states of Paraíba and Pernambuco, Brazil. Its distribution in Pernambuco is located in the Metropolitan Region of Recife/Região Metropolitana do Recife (RMR), covering the municipalities of Abreu e Lima and Olinda. Studies have been carried out in these municipalities, verifying the presence of Naturally Occurring Radioactive Material (NORM) in different matrices: soil, groundwater, air and fruit. Given these facts, the need arose to carry out human biomonitoring (HBM) in residents of these municipalities. Therefore, the aim of this study was to assess possible DNA damage in the residents of Olinda and Abreu e Lima by means of the comet assay using lymphocytes. The results showed high levels 3 and 4 damage to the DNA of the volunteers in the sample group who are under the influence of NORM, demonstrating a statistically significant difference in the damage index when compared to the control group. It is suggested that the genotoxic results found may be related to the NORM present in the municipality of Abreu e Lima, thus influencing the health of its residents. The research is relevant because it is a pioneer in the generation of scientific knowledge in the area of the study of uraniferous phosphorite using HBM.
Derechos de autor 2025 Vinícius Henrique Teixeira Morais, Dewson Rocha Pereira, João Emanuel Firmo Pinto, Osana Diniz Ferreira, Ana Maria Mendonça de Albuquerque Melo https://creativecommons.org/licenses/by/4.0
Evaluaciones de los posibles efectos mutagénicos y genotóxicos de los 2-ACBs: subproductos generados a partir de alimentos irradiados
Este estudio investiga los posibles efectos mutagénicos y genotóxicos de los subproductos 2-Alquilciclobutanonas (2-ACBs), formados en alimentos irradiados. Las 2-ACBs son compuestos derivados de la irradiación de alimentos que contienen grasa, con reconocido potencial genotóxico. La investigación se centró en los compuestos 2-dodecilciclobutanona (2-dDCB) y 2-tetradecilciclobutanona (2-tDCB), evaluando su mutagenicidad mediante el ensayo de micronúcleos en líneas celulares hepáticas (HepG2, BRL3A y HTC) y genotoxicidad a través del ensayo de Ames utilizando cinco cepas bacterianas (TA-98, TA-100, TA-1535, TA-1537 y WP2uvrA). Los resultados del ensayo de Ames indicaron que 2-dDCB y 2-tDCB no aumentaron significativamente las tasas de reversión mutagénica, mientras que los ensayos de micronúcleos mostraron ausencia de daños genotóxicos en las líneas celulares analizadas. Se concluye que, en las concentraciones evaluadas, los compuestos 2-dDCB y 2-tDCB no presentan potencial mutagénico ni genotóxico, lo que corrobora la seguridad de los alimentos irradiados. No obstante, se recomienda la realización de investigaciones adicionales para evaluar los efectos a largo plazo y bajo diferentes condiciones de irradiación
Alimento Irradiado, 2-Alquilciclobutanonas (2-ACBs), 2-Dodecilciclobutanonas (2-dDCBs), 2-Tetradecilciclobutanonas (2-tDCBs), Prueba de Ames, Ensayo de Micronúcleos.
Derechos de autor 2025 Angélica Bueno Barbezan, Ana Carolina de Araújo Bispo, Bruno Melo Mendes, Daniel Perez Vieira, Luma Ramirez de Carvalho, Glaucia Maria Machado-Santelli, Anna Lúcia Casaas Haasis Villavicencio https://creativecommons.org/licenses/by/4.0
Evaluation of Public Exposure to Gamma Radiation in Cotonou, Southern Benin
The objective of this study is to assess public exposure to natural background gamma radiation in Cotonou, southern Benin, in West Africa. This is a cross-sectional study with both descriptive and analytical aims, conducted from July to December 2024. The methodology involved continuous, georeferenced measurement of the ambient gamma dose rate at a height of one meter (1 m) above ground level using a spectrometer. The study sites included city streets and selected markets, including Dantokpa, an open-air market, and eight indoor markets. A total of 341,991 data points were recorded along the streets and 16,202 were recorded within the markets. The ambient gamma dose equivalent rate along the streets ranged from 4.67 to 136.84 nSv·h– 1, with an average of 25.11 ± 12.72 nSv·h– 1. The highest average rate was observed in District 5, which hosts a cement manufacturing plant. The average dose rates were 23.71 ± 12.90 nSv·h– 1 at the Dantokpa market and 69.72 ± 21.96 nSv·h– 1 in the indoor markets. In the latter, the dose rates were higher than those recorded in their respective districts. The estimated external annual effective doses were 0.04 ± 0.02 mSv for streets, 0.10 ± 0.06 mSv for Dantokpa, and 0.30 ± 0.09 mSv for indoor markets. These values remain below the worldwide average of 0.87 mSv, as recognized by the United Nations Scientific Committee on the Effects of Atomic Radiation for public exposure to natural radiation of terrestrial and cosmic origin. Overall, ambient gamma radiation exposure in Cotonou is low, though higher in enclosed market environments. These values may serve as baseline references for future studies in Cotonou and other African cities.
Derechos de autor 2025 Dr Gilles David Houndetoungan, Dr Olatoundé Herbert Fachinan, Dr Mahougnon Boniface Zinsou, Dr Sonia Mahussi Gwladys Adjadohoun, Dr Gibril Abogbo, Dr Bonaventure Awede, Dr Martial Zoungrana, Dr Kuassi Marcellin Amoussou-Guenou https://creativecommons.org/licenses/by/4.0
Thermal-Hydraulic Analyzes of a Slow Loss of Flow Accident in the IEA-R1 nuclear reactor using RELAP and CFD Codes
Among the most critical accidents for the IEA-R1, there is the Loss of Flow Accident (LOFA) in which a sudden and abrupt stop of the primary pump causes the loss of flow. Traditionally, this kind of accident is analyzed by thermal-hydraulic system codes. However, they can overestimate the fluid and fuel temperature along the transient by up to 20%. Moreover, thermal-hydraulic system codes can face difficulties to capture three-dimension phenomenon, such as the natural convection. Meanwhile, Computational Fluid Dynamics (CFD) analysis has shown good results when analyzing open-pool research reactor accidents even dealing with flow inversion. This work presents a thermal-hydraulic analysis of a Slow Loss of Flow Accident (SLOFA) in the IEA-R1 using the RELAP5 code and the commercial CFD code Ansys CFX®. The objective is to combine the advantages of both approaches. The system code was used to find the transient boundary conditions for a CFD model. The CFD software solved the detailed flow pattern in a quarter of a fuel channel. The numerical results showed good agreement with the benchmark data. The peak temperatures were overestimated in only 1.8 °C in the fluid and 3 °C in the cladding.
Derechos de autor 2025 Franklin Cândido Costa, Antônio Belchior Júnior, Walmir Maximo Torres, Pedro Esnesto Umbehaun, Delvonei Alves D. Andrade https://creativecommons.org/licenses/by/4.0
Influence of dose rate on radiotherapy treatment of the U87MG cell line through cell viability
Glioblastoma multiforme is a tumor that affects glial cells and is common in humans, being the most aggressive of gliomas. Patients, after diagnosis, have an average survival of just over a year, even when undergoing standard treatment. Given the low estimated survival of patients with this type of tumor, the objective of the study is to investigate the contribution of dose rate in radiotherapeutic treatment using a human glioblastoma cell line called U87MG, through the MTT (brometo de 3-[4,5-dimetiltiazol-2-il]-2,5-difenil tetrazólio) cell viability assay. Three dose rates were tested, including 400 cGy/min which is used clinically in patients, as well as 1.400 and 3.300 cGy/min from a clinical linear accelerator. Sterile culture plates with U87MG cells were irradiated, then, manipulated in the laboratory for the execution of the cell viability assay. The irradiated plates showed lower cell viability than the non-irradiated group, but there was no significant difference in viability among the different tested dose rates.
Déborah Assis de Almeida Carneiro Carneiro
Derechos de autor 2025 Arthur Rocha, Ruy Rayol Neto, Debora Assis Carneiro, Delano Valdivino Batista, Luiz Antonio Ribeiro da Rosa, Mariana Paranhos Stelling, Simone Coutinho Cardoso https://creativecommons.org/licenses/by/4.0
Avaliação da Lixiviação de Radionuclídeos e Exposição Externa em Materiais de Construção Contendo Resíduos NORM
A produção de dióxido de titânio no Brasil gera aproximadamente 30.000 toneladas de resíduos anualmente, conhecido como resíduo de minério não reagido (UOW), que atualmente são descartados em aterros industriais. Este resíduo é enriquecido com radionuclídeos naturais da série de decaimento de urânio e tório e é classificado como Material Radioativo de Ocorrência Natural (NORM). A reutilização de resíduos NORM em materiais de construção só é permitida se as concentrações de atividade dos radionuclídeos no produto final não representarem qualquer risco adicional de exposição para os indivíduos. A exposição à radiação de tais materiais pode ser classificada como externa - devido à irradiação gama direta - ou interna - resultante da inalação de radônio (222Rn) e seus produtos de decaimento de curta duração. Em um estudo anterior, os autores avaliaram a exposição indoor associada à incorporação de até 23% de UOW em cimento e blocos intertravados. Este estudo avaliou a viabilidade do uso desses materiais em aplicações externas, com ênfase particular no potencial de lixiviação de radionuclídeos e exposição radiológica externa. Blocos de cimento e intertravados contendo proporções variadas de rejeito de minério não reagido (0%, 3,5% e 23%) foram submetidos ao intemperismo por 60 dias. As concentrações de atividade de 238U, 226Ra, 210Pb, 232Th, 228Ra, e 40K no lixiviado foram medidas por espectrometria gama e espectrofotometria. Não foi observado aumento significativo nas concentrações de radionuclídeos no lixiviado de blocos contendo 3,5% e 23% de UOW em comparação com aqueles sem nenhum resíduo. A exposição à radiação gama permaneceu consistentemente abaixo de 0,1 mSv, e nenhuma mudança significativa foi detectada nas concentrações de radônio nas proximidades do experimento. Os resultados indicam que a incorporação de até 23% de UOW em blocos de cimento e de intertravados é segura e está em conformidade com os limites regulatórios relacionados à contaminação das águas subterrâneas e à exposição humana ao usar esses materiais em ambiente ao ar livre.
Derechos de autor 2025 Barbara Paci Mazzilli, Fenanda Yuri Muta, Lara Vitória Santos Couto, Antonio Luis Silva Costa, Vilmar Pedreira Oliveira, André Luis Batista Cabral https://creativecommons.org/licenses/by/4.0
Assessment of Natural Radioactivity in a Residence in Belo Horizonte
Natural radioactivity comes from natural radionuclides present in rocks and soil and from cosmic rays. In addition to gamma-emitting radionuclides, radon stands out, which is a carcinogenic gas. In nature, radon occurs as radioisotopes: 222Rn (half-life time, t1/2,of 3.83 d), 219Rn (t1/2 = 3.92 s) and 220Rn (or thoron, t1/2 = 54.5 s). The World Health Organization (OMS) recommends that it be measured in homes, with the recommended limit being 100 Bq/m3 and the maximum limit being 300 Bq/m3. This work evaluates the origin of natural radiation in a residence in Belo Horizonte, Minas Gerais, Brazil, in which was observed radon concentrations above the limits established by the OMS. The detectors used were: nuclear trace detectors type CR-39, electrets (E-PERM), AlphaGUARD (AG) and the detector RS-230. The result of the 222Rn concentration measured in the electrets in the rooms of the residence varied from 14,8 Bq/m3 to 932 Bq/m3. At this highest point, the result of the average concentration of AlphaGUARD was from 4.78 kB/m3, with a maximum value of 8.5 kBq/m3. The concentration of 220Rn varied Bq/m3 Bq/m3. As this is a basement-type room, the bedroom next door was investigated, in which it is highlighted that the radon concentration of the detector CR-39 was from 445 Bq/m3, AG of 198.2 Bq/m3 with a maximum value of 350 Bq/m3, and electret of 29.6 Bq/m3. Gamma scanning with the RS-230 indicates higher counts on uncoated walls. Measurements of radon in the water showed background concentrations. It is concluded that poor ventilation of the location must be the biggest contributor to the high concentration of 222Rn, which originates mainly from the soil. The thoron concentration was higher in construction materials due to the measurement method. The instrumentation used allows a complete and comparative study between detectors in order to find the origin of natural radionuclides and subsequently suggest appropriate mitigation measures. In future studies, radon concentration in the soil and radon progeny will be measured.
Derechos de autor 2024 Sueli da Conceição Teixeira Coelho, T.O. Santos, L. C. Takahashi, I. N. S. Ferreira, R. G. Passos https://creativecommons.org/licenses/by/4.0
Analysis of TG-43 dosimetric parameters for an Ir-192 HDR brachytherapy source using with the Geant4 toolkit
This study evaluated the dosimetric parameters of the Buchler G089 192Ir high-dose-rate brachytherapy source using the TG-43 formalism and Monte Carlo simulations with the Geant4 toolkit. The radial dose function and the anisotropy function were obtained for this source. For the radial dose function, a small discrepancy could be observed for larger radii. The dose rate constant (Λ) was also calculated in this study (1.114 cGy·h⁻¹·U⁻¹) showing a maximum relative difference of 0.45% when compared with reference values (1.119 and 1.115 cGy·h⁻¹·U⁻¹). The absorbed doses were obtained by positioning the source in the lowest voxel of the ICRP male phantom prostate and benchmarked against previous studies. For comparison criteria, the Amersham 6711-Oncoseed 125I source was also modeled and inserted in the same position of the prostate. Additionally, the dose enhancement effect due to the presence of gold nanoparticles (GNPs) was analyzed for the ¹⁹²Ir source, considering a homogeneous concentration of 30 mg·g⁻¹ in a tumor region simulated in the peripheral zone of the prostate. An approximately 18.5% increase in the absorbed dose was observed in this region, in agreement with results from previous studies.
Derechos de autor 2025 Alice Albuquerque, Dr. Luiz Antônio Ribeiro da Rosa, Dr. Denison S. Santos https://creativecommons.org/licenses/by/4.0
Computational Analysis of Gamma-Ray and Fast Neutron Attenuation performance of some Thorium and Uranium Compounds
Evaluation of the radiation shielding effectiveness of some compounds including Fe, Th, Y, Nb, Ta, Ti, and U have been computed for energy absorption and total interaction in the photon energy range from 0.015 to 15 MeV. The effective atomic number (Zeff), of these compounds was determined via the mass attenuation (µ/ρ, cm2/g) and mass energy absorption (µ/ρ, cm2/g)en coefficients. Accordingly, the values ​​of Zeff have been computed for total photon interaction (ZIeff) and energy absorption (ZAeff) using Py-MLBUF and Phy-X/PSD codes. The effective removal cross section for fast neutrons (ΣR, cm-1) and attenuation lengths were also calculated to study the attenuation properties of fast neutrons. The results displayed showed that, Zeff of S1 (UO2) and S2 (ThSiO4) are comparatively higher than the Zeff of the remaining compounds, while S7 (Fe(UO2)2(PO4)2.8(H2O)) possesses the lowest values of Zeff. The obtained results also show that ZAeff should be used instead of ZIeff when the quantity of interest is energy dissipation. In addition, the calculated values of ΣR ​​for the tested compounds were found to be close and ranged from 0.079 cm-1 for S4 to 0.146 cm-1 for S1. Moreover, comparison of the calculated values ​​for different shielding parameters showed good agreement between the proposed methods. Finally, this study could be useful in applications of these compounds for shielding requirements from gamma-ray and fast neutron in different fields such as, nuclear fuel cycles and medical shielding in uranium-handling environments.
International Radiation Protection Association (IRPA)
Derechos de autor 2025 A. M. Osman https://creativecommons.org/licenses/by/4.0
Caracterización del Fosfogeso de Cartagena y Huelva, España
El fosfogeso (PG), subproducto de la producción de ácido fosfórico, es reconocido como un Material Radioactivo Naturalmente Ocorrente con Tecnología Mejorada (TENORM) debido a su enriquecimiento en radionucleidos de la serie del uranio. En España, particularmente en Huelva y Cartagena, grandes pilas de PG generan crecientes preocupaciones ambientales relacionadas con la contaminación del suelo y del agua subterránea. Este estudio presenta una evaluación mineralógica y ambiental preliminar de muestras de PG de estas regiones, utilizando difracción de rayos X (DRX) y fluorescencia de rayos X por dispersión de energía (EDXRF). El yeso (CaSO4 · 2 H2O) fue identificado como la fase cristalina dominante en todas las muestras. Variaciones en la intensidad de los picos y en la orientación preferencial sugieren heterogeneidad mineralógica vinculada a las propiedades de la roca fuente y a las condiciones de procesamiento. Desplazamientos sutiles y ensanchamiento de los picos indican cohidratación con H₂O y D₂O, consistente con fraccionamiento isotópico durante la cristalización. El análisis por EDXRF también reveló la presencia de metales pesados como cromo (Cr), níquel (Ni), plomo (Pb) y zinc (Zn), así como elementos traza como estroncio (Sr) y bario (Ba), que pueden influir en el riesgo ambiental. No se detectaron fases discretas de uranio, torio o radio mediante DRX, lo que respalda su probable incorporación a niveles traza por sustitución o adsorción, hallazgo confirmado por el análisis elemental por EDXRF. Los datos mineralógicos y químicos obtenidos constituyen una base de referencia esencial para sustentar etapas futuras de caracterización más detallada e integral del material, en las cuales se integrarán la espectrometría gamma, el ICP-MS y el SEM, con el fin de evaluar la especiación química y el riesgo ambiental asociado al fosfoyeso (PG). Según datos de Web of Science, se publicaron más de 300 artículos revisados por pares sobre PG a nivel mundial entre 2020 y 2025, con China, Marruecos y Brasil liderando la producción científica. El creciente interés en la investigación subraya la relevancia estratégica de una caracterización detallada del PG para orientar la reutilización segura, las decisiones regulatorias y las aplicaciones en economía circular.
Derechos de autor 2025 Carla Ricardo, Cristina Trull-Hernandis, Belen Juste, Gumersindo Verdú, Claubia Pereira, Arno Heeren https://creativecommons.org/licenses/by/4.0
Estimation of Typical Values (DRL) in Angioplasties Performed at a Radiology Service of a Hospital in Southern Brazil
Interventional radiology involves diagnostic and therapeutic interventions using X-ray-emitting equipment. Due to the high radiation doses administered to patients during these procedures, there is a significant risk of severe tissue reactions resulting from prolonged exposure. To prevent unnecessary high doses during patient exposures, the International Commission on Radiological Protection recommends the use of Diagnostic Reference Levels (DRLs) as an effective tool for optimizing procedures in diagnostic or interventional radiology services. This study aimed to estimate the DRLs (typical values) resulting from interventional radiology procedures conducted in a public hospital in southern Brazil. To achieve this, a database was developed to facilitate the collection of information regarding exposures during interventional procedures, enabling the establishment of DRLs specific to a single facility, known as typical values. Patient and procedure data were collected and tabulated by the Radiation Protection Service (SPR) of the hospital through consultation with the interventional radiology service’s logbook or, if necessary, the State Information System of Risk and Potential Benefit (SIERBP), followed by the application of exclusion criteria. After data collection, the typical doses received by adult patients undergoing these procedures were estimated through simple descriptive statistics, using the median of the data distribution and the standard deviation. The results obtained provide a better understanding of the necessary actions, whether optimization or protocol review, to ensure the radiological protection of patients. This approach has the potential to benefit not only the patients but also the entire professional team involved in the interventional radiology service.
Estimation of Diagnostic Reference Levels
Derechos de autor 2025 Fernando Rockembach Mazuim, Isadora Tomanqueves Costa, Florencia Agustina Gutierrez Perez, Cristiny Tretto Lemes Pereira Dutra, Marcos Araquem Scopel, Tiago Trindade Hahn, Catia Simone Griebler Gomes, Daiane Cristini Barbosa Souza https://creativecommons.org/licenses/by/4.0
Application of TLD Dosimeters (CaSO₄: Dy and LiF:Mg,Ti) for Environmental Assessment of H*(10) in Field Studies.
The increasing use of ionizing radiation across various sectors of society underscores the need for effective monitoring of occupationally exposed individuals (OEIs), the public, and the environment. Within this framework, environmental radiation protection programs adopt the ambient dose equivalent H*(10) as the operational quantity, as defined by the International Commission on Radiological Protection (ICRP) and recommended by the International Atomic Energy Agency (IAEA), due to its suitability for estimating the risk of external exposure under field conditions. This study assessed the ambient dose equivalent H*(10) through a field survey conducted around the perimeter of the IPEN facilities. Eight monitoring points were selected near thirteen already existing environmental sampling stations, covering approximately 60% of the area. The monitoring was structured in three stages: (i) a comparative analysis between monthly and quarterly measurements using CaSO₄:Dy thermoluminescent detectors (TLDs), which showed proportional responses; (ii) a comparison between quarterly measurements with CaSO₄:Dy and LiF:Mg,Ti TLDs, which demonstrated equivalent results; and (iii) a comparison between the quarterly CaSO₄:Dy data from this study and those obtained in the Environmental Radiological Monitoring Program of the Center for Metrology of Ionizing Radiations of IPEN (ERMP/CEMRI-IPEN), which indicated consistent and satisfactory results, confirming the reliability of using H*(10) in the applied monitoring system. Statistical and uncertainty analyses further confirmed the robustness of the environmental monitoring with thermoluminescent dosimeters. Proper detector selection remains essential to ensure accuracy, minimize variability, and enhance environmental radiation monitoring programs.
International Joint Conference Radio (RADIO)
Derechos de autor 2025 Ms. Teresa Soares, Dra. Linda Caldas, V. P. Campos, L. L. Campos https://creativecommons.org/licenses/by/4.0
Preliminary Studies on the Distribution of Stable Pb and Pb-210 in the Maternal and Fetal Portions of Human Placentas
Fetal growth and survival are solely dependent on the placenta, making the characterization of toxic elements in this tissue crucial for understanding exposure during pregnancy. Stable lead (Pb) and Pb-210 are toxic elements of particular interest in this context. Stable Pb has been linked to developmental changes in children, while Pb-210, a beta-emitting radionuclide with a 22.3-year half-life, can increase cancer risk, particularly bone sarcomas, when present in excess. Placental uptake of stable Pb and Pb-210 can occur through ingestion of food and water, as well as inhalation of air, with smoking and air pollution being significant contributing factors. Recent research suggests that even low levels of environmental chemicals, especially potentially toxic elements, can significantly disrupt placental homeostasis. This preliminary study aimed at determining the concentrations of stable Pb and Pb-210 in the maternal and fetal portions of placentas from eight women who delivered at the Hospital das Clínicas, Faculdade de Medicina, University of São Paulo. Concentrations from 5.7 ± 1.2 ng g-1 to 210.3 ± 2.4 ng g-1 and from 31.5 ± 2.9 Bq kg-1 to 43.3 ± 3.1 Bq kg-1 were obtained for stable Pb and Pb-210, respectively. The results showed that both elements can cross the placental barrier and reach the fetal compartment, albeit at lower concentrations than in the maternal portion.
Derechos de autor 2025 Laíssa A. Bonifacio, Nathália V. dos Santos, Naomi Akiba, Maciel S. Luz, Rossana P. V. Francisco, Barbara P. Mazzilli https://creativecommons.org/licenses/by/4.0
Influencia de la Radiación Ionizante en la Manufactura Aditiva de ABS
Este trabajo presenta un análisis sobre cómo un material común en la impresión 3D, el ABS, responde a la interacción constante con la radiación ionizante. Se propone, por lo tanto, una investigación detallada sobre los cambios en la estructura física y química de este material. Para ello, se prepararon cuerpos de prueba impresos específicamente para cada ensayo ejecutado, siendo estos sólidos y con un relleno del 20%. De esta manera, los ensayos se centraron en los cambios estructurales (fisicoquímicos) sufridos tras el contacto con la radiación. Así, algunos cuerpos de prueba fueron irradiados, mientras que otros no. A todos se les aplicaron pruebas de tracción, dureza, compresión y un ensayo balístico. Habiendo sido irradiados en el Instituto de Defensa Química, Biológica, Radiológica y Nuclear (IDQBRN), a través de una colaboración con el Instituto Militar de Ingeniería (IME), el objetivo de esta investigación es analizar no solo las modificaciones fisicoquímicas del filamento ABS, sino también determinar su durabilidad tras cierto período de exposición. El artículo examina cómo la radiación afecta las propiedades mecánicas de este material y discute las implicaciones para aplicaciones industriales y comerciales.
Brazilian Congress on Metrology of Ionizing Radiation (CBMRI)
Latin-American Congress on Solid State Dosimetry and Radiation Measurements (LASSD)
II Simpósio Internacional sobre Protección Radiologica, Cusco (SIPR)
IX Congresso de Proteção Contra Radiações da Comunidade dos Países de Língua Portuguesa (PCR-CPLP)
Semana Nacional de la Ingeniería Nuclear y Energética y de las Ciencias Radiológicas (SENCER)
Derechos de autor 2025 Karine L. Carvalho, Wallace V. Nunes, Ary M. de Azevedo, Paulo C. R. Silveira https://creativecommons.org/licenses/by/4.0
Calibration Of The Short Irradiation Facility For k0 - NAA Implementation At The IEA-R1 Reactor
The short irradiation facility of the IEA-R1 nuclear research reactor at IPEN, São Paulo, Brazil, has been used for short irradiation of samples for the purpose of determining the concentration of elements of these samples through the use of the instrumental neutron activation analysis technique. With the aim of implementing the k0-NAA method at the Neutron Activation Analysis Laboratory (LAN), the reactor parameters a and f were obtained using the bare triple method. In this method, a set of three neutron flux monitors were irradiated without Cd-cover. The efficiency curve of the gamma-ray spectrometer used was determined by measuring calibrated radioactive sources at the commonly used counting geometries. The results for the parameters a and f were respectively 0.0384±0.0016 and 35.67±0.26. This value of f shows that the neutrons in the irradiation position are well thermalized.The variation of these parameters was studied with time and the reproducibility was verified.
The Meeting on Nuclear Applications (ENAN) 2019
Derechos de autor 2021 Brazilian Journal of Radiation Sciences (BJRS) https://creativecommons.org/licenses/by/4.0
Fabrication and Dosimetric Evaluation of a 3D-Printed Multichannel Cylindrical Applicator Prototype for HDR Gynecological Brachytherapy
High dose-rate (HDR) brachytherapy is widely used in the treatment of gynecological cancers, but the availability of multichannel applicators remains limited in many radiotherapy centers. 3D printing has emerged as a viable alternative for manufacturing customized devices, allowing for optimized dose distribution and reduced exposure to organs at risk. This study aimed to develop and evaluate a 3D-printed multichannel cylindrical applicator for gynecological brachytherapy. The printing material was selected based on its physical properties, followed by an analysis of Hounsfield Units (HU) for different infill percentages and printing patterns. The applicator was printed using polylactic acid (PLA), and different physical and imaging tests were performed. The dose distributions obtained with the 3D-printed multichannel applicator and a single-channel were compared, with focus on target coverage and organ-at-risk exposure. Dosimetric evaluation was performed using Gafchromic® EBT4 film. The results show that the multichannel applicator enabled better dose conformity, reducing rectal exposure compared to the single-channel applicator while maintaining target coverage. Gamma analysis confirmed the accuracy of the calculated dose distribution. 3D printing seems to be a viable alternative to produce customized applicators, potentially expanding therapeutic options in gynecological brachytherapy, however, future studies should investigate the biocompatibility of the material and the clinical feasibility of the applicator.
Derechos de autor 2025 Patrícia Vieira Guimarães, Saulo Santos Fortes, Delano Valdivino Santos Batista, Rechele Grazziotin Reisner https://creativecommons.org/licenses/by/4.0
The Brazilian panorama for the calibration of Y-90 microspheres
The combination therapy approaches are gaining popularity, particularly the radiopharmaceutical therapy with external radiotherapy, immunotherapy or both. Radioembolization using Yttrium-90 Microspheres, SIR-Spheres and TheraSphere, has been used clinically in the treatment of locally advanced and unresectable Hepatic Carcinomas. According to the literature, the standardization of microspheres is not yet well established. In view of the practice of 90Y in therapies in Brazil, it is essential to develop solid standards for its measurement, in order to verify the absorbed radiation dose and its administration to the patient. This paper proposes a study of the existing standardization infrastructure for 90Y microspheres through a literature review and analysis of the measuring instruments available at the National Laboratory for Ionizing Radiation Metrology, a general analysis was made of the spectrometry and calibration methods available in Brazil, specifically at LNMRI, evaluating those suitable for use in the standardization of Yttrium microspheres. The results showed that in the period between 2000 and 2024 90Y was widely cited in treatment by radioembolization with microspheres, qualitative and quantitative evaluation of the activity quantity in PET/CT scans and its metrological characterization involving proficiency tests, study of impurities, standardization by primary and secondary methods
Y-90 microspheres, Radioembolization, Standardization.
Derechos de autor 2025 Thamyra Cybelle Vieira dos Santos, Ms Dayana Azeredo da Conceição, Dr José Ubiratan Delgado https://creativecommons.org/licenses/by/4.0
Curva de calibración dosis–efecto automatizada para exposiciones a rayos X utilizando el ensayo de micronúcleos con bloqueo de citocinesis.
Este artículo presenta el desarrollo de una curva de calibración dosis–efecto para exposiciones a rayos X en el rango de 0 a 4 Gy utilizando el ensayo de micronúcleos con bloqueo de citocinesis y análisis automatizado, siendo el primer esfuerzo de este tipo reportado en América Latina. Este trabajo establece un referente regional para metodologías de alta capacidad en biodosimetría citogenética, destacando su potencial para mejorar la eficiencia operativa y reducir los tiempos de respuesta en emergencias radiológicas. Métodos: Se irradiaron muestras de sangre de seis donantes sanos con rayos X en siete niveles de dosis (0–4 Gy) utilizando un acelerador lineal de 6 MV calibrado. Se incluyeron dos muestras ciegas (1.5 y 3 Gy) para validación. El ensayo CBMN se realizó siguiendo los protocolos del OIEA; las láminas teñidas con DAPI se analizaron utilizando un microscopio automatizado AxioImager.Z2 integrado con el sistema Metafer4 de MetaSystems y el software clasificador MNScoreX. Para el ajuste del modelo se empleó una regresión binomial negativa (NB1), que considera la sobredispersión en la frecuencia de micronúcleos (MN). Resultados: El análisis automatizado de linfocitos binucleados mostró un aumento dependiente de la dosis en la frecuencia de MN. El modelo ajustado presentó una relación lineal–cuadrática: Y = 0.0545 + 0.0448·D + 0.0145·D², con todos los coeficientes estadísticamente significativos (p < 0.001). Las estimaciones de dosis para las muestras ciegas (1.5 y 3 Gy) coincidieron con las dosis reales dentro de los intervalos de confianza del 95%, y todos los puntajes z fueron < |3|. Conclusiones: La curva dosis respuesta sigue una función lineal–cuadrática, permitió una estimación precisa de las dosis en las muestras incógnitas, cumpliendo con los criterios de validación. Estos resultados destacan el valor de combinar microscopía automatizada con modelos estadísticos robustos para lograr evaluaciones de dosis confiables, especialmente como métodos de alto rendimiento y situaciones de emergencia radiológica.
Derechos de autor 2025 Fabio Andrés Chaves-Campos, Fernando Ortíz-Morales, Anthony Cordero-Ramírez, Julián Alonso Gómez-Castro, Jorge Ernesto González-Mesa https://creativecommons.org/licenses/by/4.0
The EDXRF Analysis to Monitor Iron Deficiency Anemia
Iron Deficiency Anemia is a significant global issue, particularly affecting pregnant women and young children. Traditional methods of diagnosing iron-deficiency anemia generally require extensive and costly laboratory procedures. This study explores the feasibility of using portable Energy Dispersive X-ray Fluorescence (EDXRF) technology for assessing iron concentration in whole blood samples from donors diagnosed with iron deficiency anemia. The results indicated a marked decrease in iron levels in the blood samples from patients with anemia compared to the control group. The EDXRF technique demonstrated several advantages, including simplicity in sample collection, rapid measurement time, and low cost. This method is particularly promising for use in situations where biological material is limited, such as in pediatric practices for newborns. The study concludes that portable EDXRF technology is an effective and efficient tool for diagnosing iron deficiency anemia, potentially improving diagnostic accessibility and outcomes.
Derechos de autor 2025 Maria Paula de Oliveira Goes, Cibele Bugno Zamboni, Maria Gabriela Miquelino Benedito, Maria Regina Andrade Azevedo https://creativecommons.org/licenses/by/4.0
Determination of the total retention capacity of 99Mo in anionic extracting agent
The Nuclear Metrology Laboratory (LMN) at IPEN-CNEN/SP is developing a research project aimed at studying analytical techniques for determining radioactive impurities, emitting alpha and beta particles. This project started with the determination of impurities present in 99Mo, which is used to obtain the radiopharmaceutical 99mTc by means of radiochemical separation in the 99Mo/99mTc generator. The study of the anionic extracting agent Strata X-A widely used in quality analysis, was realized by means a breakthrough curve in order to validate its total exchange capacity for Mo. The breaking point was determined at (2.75 +/- 0.14) mL, showing that just one 0.5 g Strata X-A cartridge is sufficient to retain 1.0 mL of a (Na2MoO4+ 99Mo) solution in concentration of 2.42 g L- 1.
Derechos de autor 2025 Ione Makiko Yamazaki, Denise Simoes Moreira, Mauro da Silva Dias, José Antonio Seneda, Marina Fallone Koskinas https://creativecommons.org/licenses/by/4.0
Monte Carlo simulation of a 6 MV Varian Trilogy clinical linear accelerator using Geant4 for small-field dosimetry analysis
In recent decades, radiotherapy has advanced significantly due to the emergence of advanced clinical linear accelerators, enabling safer and faster treatments with reduced side effects. In this study, we present a Monte Carlo simulation of a 6 MV Varian Trilogy clinical linear accelerator using the Geant4 toolkit to analyze dosimetric parameters, with a focus on small photon fields. The simulation models phase-space files generated at key beam-modification stages. Validation was performed by comparing simulated depth dose curves (PDD) and dose profiles with experimental measurements for the 6 MV photon beam, employing the gamma index (3%/3 mm criteria) to quantify the degree of agreement in the PDDs. The results agreed within a 2% difference, with over 95% of points passing the gamma analysis for a 10 x 10 cm² field. The developed framework allows for the calculation of correction factors for small-field dosimetry, addressing challenges such as lateral electronic disequilibrium in high-energy 6 MV beams, and comparing them with established values in the literature. These capabilities are particularly important for measurements of small fields used in advanced radiotherapy techniques, including Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiotherapy (SBRT), where high precision in dose deposition is essential. Overall, this work establishes a robust and flexible Geant4-based platform for simulating clinical linear accelerators, contributing to the development of more accurate dosimetric protocols for high-energy photon therapy in small fields. Preliminary observations suggest notable output factor discrepancies in small photon fields (<3x3 cm2), indicating the potential need for detector-specific correction factors. Ongoing analysis aims to confirm these trends.
Derechos de autor 2025 Andre Luiz de Carvalho Ribeiro, Alex Cristóvão Holanda de Oliveira, Leonardo Peres da Silva, Eduardo De Paiva https://creativecommons.org/licenses/by/4.0
Evaluation of Nuclear Material Balance by Statistical Analysis of the Material Unaccounted For (MUF)
Evaluating the nuclear material balance is an essential tool that can be used to assess the validity of the operator’s declarations of existing quantities of nuclear material from a facility, with an effect on safeguards agreements, where applicable. In summary, evaluating the nuclear material balance and associated safeguards activities enables the national regulatory authority to identify variations that may indicate deviations. A specific strategy used to detect potential deviations from assessing the material balance is known as "diversion into MUF", where MUF refers to the parameter Material Unaccounted For. It represents the difference between the book inventory and the ending physical inventory at the end of the material balance period. This evaluation is conducted through statistical analysis of the standard deviation of the MUF (σMUF) parameter, using an anonymous Brazilian facility as a case study. The ultimate goal is to implement this analysis within Brazil's control and accounting system, known as e-Gamma. This will enable the system to automatically perform such analyses for all facilities nationwide during each accounting period. This statistical study can be a powerful predictor of diversion, utilizing the σMUF parameter as a valuable resource. It is possible to suggest implementing this evaluation in control and accounting systems to increase efficiency in identifying and resolving discrepancies and anomalies, which is of fundamental importance in improving the reliability of a control system within the national scenario. Considering the international scenario, a country that increases its capacity to verify the accounting of nuclear material under its custody will tend to occupy a position of autonomy among its peers.
Derechos de autor 2025 Larissa R. P. Xavier, Luiz Antônio Mello, José Carlos C. Amorim, Jakler Nichele, Edson Ramos Andrade https://creativecommons.org/licenses/by/4.0
Development of a semi-analytical nodal methodology for one-dimensional eigenvalue problems based on multigroup neutron transport theory using the discrete ordinate formulation
A semi-analytical nodal methodology is described in this paper for obtaining the numerical solution of eigenvalue problems based on neutron transport theory, in slab geometry, with isotropic scattering, using the discrete ordinates and multigroup energy formulation. This new approach applies a quadratic polynomial approximation only to the fission term in the transport equation, which justifies the method being classified as semi-analytical. The numerical solution is obtained through two interconnected iterative processes: the outer iterative process, which uses the power method to obtain successive estimates for the fission source and the effective multiplication factor (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>k</m:r></m:e><m:sub><m:r>eff</m:r></m:sub></m:sSub></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 'Times New Roman'; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: PT-BR; mso-fareast-language: PT-BR; mso-bidi-language: AR-SA;"> ), and the internal iterative process, which aims to obtain successive estimates of the angular neutron fluxes emerging from the homogeneous regions throughout the spatial domain. Once the eigenvalues are calculated, for each outer power iteration, the angular fluxes of neutrons emerging at the node faces and in the sweeping direction of the internal iterative process are estimated. These are incoming fluxes at the faces of adjacent nodes, which ensures the continuity of the numerical solution. Computational algorithms were implemented in MATLAB. Numerical results for a typical benchmark problem considering an ADS, c.f., Accelerator-Driven Subcritical Reactor, type model are provided to illustrate the accuracy of the converged numerical solutions in coarse-mesh calculations. Although the method is not free from spatial truncation error, the results for the benchmark problem were considered satisfactory with one node per region, and refining the spatial domain did not result in a high computational cost in terms of response time, with results approaching those of analytical solutions.
Meeting on Nuclear Reactor Physics and Thermal Hydraulics (ENFIR)
Neutron transport equation, Multigroup energy formulation, Nodal methodology
Derechos de autor 2025 Natália Rocha Pinheiro, Francisco Bruno Souza Oliveira, Hermes Alves Filho https://creativecommons.org/licenses/by/4.0
Ginkgo biloba Extract: A Preliminary Study on Its Radiomitigative Potential Using the Conventional Dicentric Chromosome Assay
Radioprotectors and radiomitigators can be substances of natural or synthetic origin that, once administered to the human body, are capable of preventing, protecting against, or reducing damage caused by radiation. This study aimed to assess the radiomitigating potential of Ginkgo biloba extract by examining the frequency of dicentric chromosomes in irradiated human lymphocytes. Blood samples were obtained from a healthy volunteer. One sample was left in the laboratory as a control, and the others were irradiated in a 60Co source at a dose of 2 Gy and incubated in test concentrations of Ginkgo biloba extract (0.025 and 0.05 μg/ml) according to a standard protocol. Complete metaphases were analyzed, and the frequencies of alterations were statistically evaluated to verify the radiomitigating potential of Ginkgo biloba extract. The ANOVA and Tukey tests revealed a statistically significant difference between the groups treated and untreated with Ginkgo biloba exposed to 2 Gy of radiation (p < 0.05), indicating that both concentrations tested were able to reduce the damage. In this in vitro study, Ginkgo biloba extract was able to reduce the frequency of dicentric chromosomes in irradiated human lymphocytes, with a concentration of 0.025 μg/ml standing out.
Derechos de autor 2025 Julio Cesar Gomes da Silva, CAIO C. V. B. G, MENDES M. E., LOPES I. M. S. S., MELO A. M. M. A, LIMA F. F. https://creativecommons.org/licenses/by/4.0
Optimization of Flight Parameters for Gamma Radiation Detection and Mapping Using Drones
The application of drones in radiometric surveys has emerged as a promising solution, particularly for mapping radiation in areas that are difficult to access. This approach enables the creation of detailed distribution maps. However, the accuracy of the results is strongly influenced by the chosen flight strategy. This study explores how different flight parameters, such as speed and grid spacing, impact the quality of gamma radiation mapping, aiming to optimize the trade-off between measurement precision and operational efficiency, such as flight time and mapping coverage. To achieve this, two experimental flights were conducted using a drone equipped with a Geiger-Müller detector, with a Cs-137 source serving as a reference. The methodology involved continuous radiation measurements during flight, with data collected at predetermined points arranged in a structured grid, via GPS coordinates. This setup facilitated the development of a three-dimensional representation of the gamma dose distribution. By comparing the results of both flights, each configured with distinct operational settings, it was possible to evaluate the impact of flight parameters on the effectiveness of radiometric detection of dose rate distribution using drones. The results suggest that dose rate mapping tends to achieve higher resolution when lower flight speeds are adopted and when data collection points are more densely distributed across the surveyed area.
Derechos de autor 2025 Felipe Mamed, Alessandra Vaz, Ary Machado, Jonathan Oliveira, Leandro Silva, Paulo Barreto, Paulo Iack, Paulo Silveira, Rodrigo Curzio, Rodrigo Souza, Wallace Vallory https://creativecommons.org/licenses/by/4.0
Image quality and dose reduction in cardiac interventional procedures: application of an optimization strategy with typical dose value analysis
This study aimed to evaluate the impact of dose‑optimization strategies on radiation exposure during cardiac catheterization and angioplasty procedures. The investigation was carried out at a high‑complexity referral center using retrospective data, clinical‑protocol adjustments, and image‑quality assessments with dedicated simulators. Implemented measures included reducing the cine dose per frame and enabling post‑processing filters, resulting in reductions of up to 39 % in reference‑point kerma and 25 % in noise intensity under low‑dose conditions. In total, 714 procedures performed over five semesters were analyzed. Diagnostic reference levels (DRLs) were determined and compared with data from national and international literature. A statistically significant reduction in DAP (16.3 %) and Kₐ,r (12.8 %) was observed for catheterization procedures (p < 0.05). Although angioplasty procedures showed a similar trend, case variability limited statistical significance. The results demonstrate the effectiveness of technical interventions and continuous monitoring in lowering exposure levels, without compromising diagnostic image quality.
Derechos de autor 2025 Murilo Felisberto Morais de Assunção, Emerson Nobuyuki Itikawa, Jonas Oliveira da Silva, Guilherme Custódio Cândido Silva https://creativecommons.org/licenses/by/4.0