Cellular radiosensitivity is directly correlated with the mechanism of DNA repair, in which p53 protein plays a major role. In this context, this study correlated cell death with p53 expression in lymphocytes irradiat...Cellular radiosensitivity is directly correlated with the mechanism of DNA repair, in which p53 protein plays a major role. In this context, this study correlated cell death with p53 expression in lymphocytes irradiated in vitro with different doses of gammaradiation. For this, peripheral blood samples were collected from 10 healthy subjects. Each sample was divided in aliquots and, separately, irradiated with doses of 0,5;2 and 4 Gy. After this, peripheral blood mononuclear cells (PBMCs) were isolated and cultivated during 72 hours in 5% CO2 at 37oC without mitogen stimulation. The expression of p53 protein was evaluated by flow cytometry. In parallel, cell viability was determined by trypan blue staining. Statistical analysis was performed us-ing analysis of variance (ANOVA), differences were considered as statistically significant when p < 0.05. The results showed an increase of p53 expression with the absorbed dose, which was proportional to cell death, suggesting that p53 can be used as bioindicator of individual radiosensitivity.展开更多
Delays in the construction of nuclear reactors due to licensing issues have been a problem across the world, affecting projects in Finland, France, and the United States. Small Modular Reactors (SMRs) emerge as a tran...Delays in the construction of nuclear reactors due to licensing issues have been a problem across the world, affecting projects in Finland, France, and the United States. Small Modular Reactors (SMRs) emerge as a transition between Generations III+ and IV in order to make nuclear energy more competitive with other energy sources, including renewables. In this study, the SMR NuScale, one of the most promising projects today, is investigated for its conversion into a U-233-producing reactor through the Radkowsky seed-blanket fuel element concept, applied in the Shippingport reactor, in a parametric study. Initially, a validation of the reference reactor (NuScale) was carried out with data from technical documents and papers, thus demonstrating the agreement of the computational model carried out with the SERPENT code. Then, a parametric study is carried out to define the area of the seed and blanket region, proportions of enrichment and pitch length. Finally, a comparison is made between the production of U-233, TRU reduction, burn-up extension and neutronic and thermohydraulic safety parameters. This study demonstrates an improvement in the conversion factor and a considerable reduction in the production of TRU, in addition to the production of U-233 with a low proportion of other uranium isotopes that can lead to the beginning of the thorium cycle with already consolidated technologies.展开更多
This paper presents an overview of the state of the art about the late effects of ionizing radiation on skeletal muscle, helping new research and showing unexplored areas. For this, it was evaluated the interest repor...This paper presents an overview of the state of the art about the late effects of ionizing radiation on skeletal muscle, helping new research and showing unexplored areas. For this, it was evaluated the interest reported by the scientific literature regarding the late effects in skeletal muscle resulting from exposure to ionizing radiation. Original and experimental papers mainly containing the key expressions “ionizing radiation” and “effects on skeletal muscle” were searched in computerized databases, and published in any language. Only 33 papers matched the search criteria. Analyzing the investigated radioinduced biological effects in those contributions, four topics were identified as being of major interest: 1) alterations in cellular metabolism and protein degradation;2) repercussions on satellite cells;3) formation of fibrosis and muscle atrophy;4) tissue regeneration. It was verified that no study evaluated possible late effects related to either morphology or properties of skeletal muscles after an exposure to ionizing radiation. Several aspects do not make possible a successful replication;all experiments of eligible group of articles are discussed, such as, lack of raw data, use of no sound methodology and inappropriate statistical technique. Briefly, the subject of this review is an open field of research.展开更多
基金Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq-Brazil)for financial support.
文摘Cellular radiosensitivity is directly correlated with the mechanism of DNA repair, in which p53 protein plays a major role. In this context, this study correlated cell death with p53 expression in lymphocytes irradiated in vitro with different doses of gammaradiation. For this, peripheral blood samples were collected from 10 healthy subjects. Each sample was divided in aliquots and, separately, irradiated with doses of 0,5;2 and 4 Gy. After this, peripheral blood mononuclear cells (PBMCs) were isolated and cultivated during 72 hours in 5% CO2 at 37oC without mitogen stimulation. The expression of p53 protein was evaluated by flow cytometry. In parallel, cell viability was determined by trypan blue staining. Statistical analysis was performed us-ing analysis of variance (ANOVA), differences were considered as statistically significant when p < 0.05. The results showed an increase of p53 expression with the absorbed dose, which was proportional to cell death, suggesting that p53 can be used as bioindicator of individual radiosensitivity.
文摘Delays in the construction of nuclear reactors due to licensing issues have been a problem across the world, affecting projects in Finland, France, and the United States. Small Modular Reactors (SMRs) emerge as a transition between Generations III+ and IV in order to make nuclear energy more competitive with other energy sources, including renewables. In this study, the SMR NuScale, one of the most promising projects today, is investigated for its conversion into a U-233-producing reactor through the Radkowsky seed-blanket fuel element concept, applied in the Shippingport reactor, in a parametric study. Initially, a validation of the reference reactor (NuScale) was carried out with data from technical documents and papers, thus demonstrating the agreement of the computational model carried out with the SERPENT code. Then, a parametric study is carried out to define the area of the seed and blanket region, proportions of enrichment and pitch length. Finally, a comparison is made between the production of U-233, TRU reduction, burn-up extension and neutronic and thermohydraulic safety parameters. This study demonstrates an improvement in the conversion factor and a considerable reduction in the production of TRU, in addition to the production of U-233 with a low proportion of other uranium isotopes that can lead to the beginning of the thorium cycle with already consolidated technologies.
文摘This paper presents an overview of the state of the art about the late effects of ionizing radiation on skeletal muscle, helping new research and showing unexplored areas. For this, it was evaluated the interest reported by the scientific literature regarding the late effects in skeletal muscle resulting from exposure to ionizing radiation. Original and experimental papers mainly containing the key expressions “ionizing radiation” and “effects on skeletal muscle” were searched in computerized databases, and published in any language. Only 33 papers matched the search criteria. Analyzing the investigated radioinduced biological effects in those contributions, four topics were identified as being of major interest: 1) alterations in cellular metabolism and protein degradation;2) repercussions on satellite cells;3) formation of fibrosis and muscle atrophy;4) tissue regeneration. It was verified that no study evaluated possible late effects related to either morphology or properties of skeletal muscles after an exposure to ionizing radiation. Several aspects do not make possible a successful replication;all experiments of eligible group of articles are discussed, such as, lack of raw data, use of no sound methodology and inappropriate statistical technique. Briefly, the subject of this review is an open field of research.
