Biological Effects Of Radiation Research Articles

Radiation impact from Cell Phones and Towers on Human Health and Environment - A Review

The main key points discussed in the research paper are radiation impact from cell phones and towers electromagnetic waves on human health such as head and brain tumors, other morbidity-related outcomes and summarizes the biological effects of radio frequency (RF) and microwave radiation. The report shows that the evidence available does not provide a clear pattern to support an association between exposure to RF and microwave radiation from mobile phones and direct effects on health. It however cautions that lack of available evidence of detrimental effects on health should not be interpreted as evidence of absence of such effects and recommends a precautionary approach to the use of this communication technology until more scientific evidence becomes available. ; “These days we have Smartphones, Smartcards, Smartboards, Smart everything, but consider this: if technology is getting smarter, does that mean humans are getting dumber (ignore)?”

Radiation induced therapeutic effects in cancerous and tumor cells: A review

Present review article describes use of radiation and radionuclides on cancer and cancer cell therapeutics. It also sketches out cumulative effects of radiation exposure received by the patients during cancer diagnostics. Though, in cancer therapeutics a selected and permissible dose is provided in several cycles to ablate the neoplastic cells and improve the condition of patient, but radiation harms surrounding cells and imparts negative effects on biology of cells. Ionizing radiation (IR) promotes cancer cell death through cytotoxicity. This article emphasizes both remedial effects and biological effects of radiation and radio-resistance in cells. It suggests safe use of radionucleides by encapsulating them in nanomaterials so as to use it alternate to chemotherapy to destroy various cancer types to enhance the survival of normal cells. This article explains effect of ionizing and non-ionizing radiation on cellular metabolism and genetics.

Радиация әсерінен қартаюда митохондрия мен микроРНҚ-ның рөлі

Population aging is accelerating worldwide, straining the global economy and health services. Cellular senescence is a significant contributor to various age-related neurological and neuropsychiatric disorders, including Alzheimer’s disease and Parkinson’s disease. Some external factors, such as exposure to ionizing radiation, can accelerate aging. In recent years, it has become known that the post-transcriptional control system of gene expression by short single-stranded RNA molecules, called microRNAs, is of great importance in the regulation of normal physiological processes and in the pathogenesis of many diseases, including age-related diseases. This article reviews the biological effects of radiation, the effects of radiation on aging in various cell types, and the relevant molecular mechanisms of microRNAs.

Introducing BDNF and SNAI1 as the Crucial Targeted Genes by UV Radiation.

Introduction: Due to widespread penetration of UV radiation in human life, the biological effect of UV radiation is studied through many investigations in the field of medicine. There are many assessments about UV radiation which are concerned with protein-protein interaction (PPI) network analysis. In the present study, a network analysis associated with the complementary evaluation of UV radiation on human primary melanocytes is presented. Methods: The gene expression profiles of the irradiated human primary melanocytes and the control cells were extracted from Gene Expression Omnibus (GEO) and were evaluated via PPI network analysis and action map assessment. Results: 69 significant differentially expressed genes (DEGs) were included in the main component of the PPI network. Brain-derived neurotrophic factor (BDNF), SNAI1, and SOCS1 were highlighted as the top dysregulated and hub genes. Results indicate that BDNF and SNAI1 participate in the regulatory unit including the total hubs and top dysregulated genes. Conclusion: Considerable down-regulation of BDNF and up-regulation of SNAI1 as the two critical targeted genes by UV radiation are accompanied by gross alteration in cell functions.

Wireless technology is an environmental stressor requiring new understanding and approaches in health care.

Electromagnetic signals from everyday wireless technologies are an ever-present environmental stressor, affecting biological systems. In this article, we substantiate this statement based on the weight of evidence from papers collated within the ORSAA database (ODEB), focusing on the biological and health effects of electromagnetic fields and radiation. More specifically, the experiments investigating exposures from real-world devices and the epidemiology studies examining the effects of living near mobile phone base stations were extracted from ODEB and the number of papers showing effects was compared with the number showing no effects. The results showed that two-thirds of the experimental and epidemiological papers found significant biological effects. The breadth of biological and health categories where effects have been found was subsequently explored, revealing hundreds of papers showing fundamental biological processes that are impacted, such as protein damage, biochemical changes and oxidative stress. This understanding is targeted toward health professionals and policy makers who have not been exposed to this issue during training. To inform this readership, some of the major biological effect categories and plausible mechanisms of action from the reviewed literature are described. Also presented are a set of best practice guidelines for treating patients affected by electromagnetic exposures and for using technology safely in health care settings. In conclusion, there is an extensive evidence base revealing that significant stress to human biological systems is being imposed by exposure to everyday wireless communication devices and supporting infrastructure. This evidence is compelling enough to warrant an update in medical education and practice.

Targeted alpha therapy for glioblastoma.

According to the 2021 World Health Organization Classification of Tumors of the Central Nervous System, glioblastoma (GB) is a primary brain tumor and presents with the worst prognosis. Due to its infiltrating characteristic, molecular heterogeneity, and only partly preserved function of the blood-brain barrier, the median overall survival time is short (9-15 months), regardless of comprehensive treatment including surgery, radiotherapy, and chemotherapy. Several novel treatment strategies are under investigation. Unfortunately, none of them produced successful results; 90% of patients have a recurrence of the disease within 6 months. Local administration of the drug could be a promising approach to delivering treatment with minimized side effects, due to the recurrence of 95% glioblastomas in a margin of 2 cm at the primary site. Several ligand-receptor systems have been evaluated, such as targeting tenascin, the extracellular matrix protein, or radiolabeled somatostatin analogs, as it is overexpressed with the SSTR-2 receptor system in around 80% of gliomas. Moreover, this study revealed that the NK-1 receptor is overexpressed in GB, suggesting that substance P (SP) may serve as a ligand. A variety of radioisotopes, beta- (131I, 90Y, or 177 Lu) and alpha emitters (213Bi, 225Ac, or 211At), with different physical properties were tested for treatment. Alpha particles have many advantages over beta radiation such as short range with higher linear energy transfer. According to that characteristic, it is extremely dose delivered to the targeted cells, while reducing harm to nearby healthy tissue. Additionally, the biological effect of alpha radiation is independent of the cell cycle phase, cell oxygenation and O-6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation status. In this article, we summarize the experience with local treatment of primary and secondary GBs with locally used radioisotopes such as [213Bi]Bi-DOTA-SP or [225Ac]Ac-DOTA-SP.

WiFi Related Radiofrequency Electromagnetic Fields Promote Transposable Element Dysregulation and Genomic Instability in Drosophila melanogaster.

Exposure to artificial radio frequency electromagnetic fields (RF-EMFs) has greatly increased in recent years, thus promoting a growing scientific and social interest in deepening the biological impact of EMFs on living organisms. The current legislation governing the exposure to RF-EMFs is based exclusively on their thermal effects, without considering the possible non-thermal adverse health effects from long term exposure to EMFs. In this study we investigated the biological non-thermal effects of low-level indoor exposure to RF-EMFs produced by WiFi wireless technologies, using Drosophila melanogaster as the model system. Flies were exposed to 2.4 GHz radiofrequency in a Transverse Electromagnetic (TEM) cell device to ensure homogenous controlled fields. Signals were continuously monitored during the experiments and regulated at non thermal levels. The results of this study demonstrate that WiFi electromagnetic radiation causes extensive heterochromatin decondensation and thus a general loss of transposable elements epigenetic silencing in both germinal and neural tissues. Moreover, our findings provide evidence that WiFi related radiofrequency electromagnetic fields can induce reactive oxygen species (ROS) accumulation, genomic instability, and behavioural abnormalities. Finally, we demonstrate that WiFi radiation can synergize with RasV12 to drive tumor progression and invasion. All together, these data indicate that radiofrequency radiation emitted from WiFi devices could exert genotoxic effects in Drosophila and set the stage to further explore the biological effects of WiFi electromagnetic radiation on living organisms.

Multimodal treatment concepts of local radiation therapy with immunotherapy : Rationale for combination therapy and possible clinical treatment strategies

Immunotherapy has been established in the treatment of cancer in general and specifically in uro-oncology. The rationale to combine these therapies with radiotherapy is based on the biological effects of irradiation, which exceed the "physical" properties of irradiation to kill tumor cells. Depending on radiation dose and fractionation as well as tumor model or tumor entity used, irradiation can lead to immune stimulation or immune inhibition. As immune response is not limited to the local tumor microenvironment but occurs on asystemic level, asuccessful anticancer immune response after irradiation of one metastasis can lead to systemic tumor control (abscopal effect). Clinical trials test combination regimens in locally advanced tumors in the curative setting to improve survival rates and in the metastatic setting to prolong survival in palliative treatment. In addition, radiotherapy is used for local treatment of oligometastases and oligoprogression under palliative systemic therapy.

Biological Effects of Low Dose and Low Dose Rate Radiation

Biological Effects of Low Dose and Low Dose Rate Radiation

Abstract A023: First in-human, safety and preliminary efficacy study of (neo)adjuvant, model-based, whole-body hyperthermia treatment in advanced solid cancer patients or stage IV (TxNxM1) metastatic pancreatic adenocarcinoma patients: Liquid biopsies

Abstract Hyperthermia, the procedure of raising the temperature of a part of the entire body above normal for a defined period of time, is applied alone or as an adjunctive treatment to various established cancer treatment modalities such as radiotherapy and chemotherapy. Whole-Body Hyperthermia (WBHT), in contrast to local or regional hyperthermia, represents the only hyperthermia modality available for patients with disseminated malignancies. The biological rationale for the treatment of malignant disease by heat is driven by a number of reasons; a) the survival of cells depends on the temperature and duration of heating in a predictable and repeatable way; b) the tumor cell environment (such as hypoxia, poor nutrition, and low pH) that negatively influences the tumor cell killing by ionizing radiation and some chemotherapy regimens, is beneficially influenced by heat therapy; c) the differential sensitivity of normal and tumor cells to heat is dependent on cell type and environmental conditions; d) heat treatment enhances the biological effect of both radiation and chemotherapy agents. The biological rationale is based on a direct cell-killing effect at temperatures in the range of 41– 42°C. A systematic review of van der Horst et al, 2018, addressed clinical trials that used local or whole-body hyperthermia treatment (at variable temperatures) in pancreatic cancer patients. In those described trials, the weighted estimate of the treated population median overall survival was 11.7 compared to 5.6 for the control cohorts. In addition, locoregional hyperthermia (42-44°C) clinical trials showed that the weighted estimate median overall survival of the treated population was 15 months compared to 9 months in control cohorts. The MATTERS trial is a first in-human clinical investigation in advanced solid cancer patients or pancreatic adenocarcinoma patients (TxNxM1). The justification of the design is based on evaluation of pre-clinical data and clinical evaluation of clinical data, safety and/or performance of similar devices/therapies. The study is a mono-centric, non-randomized trial in which the safety and preliminary efficacy of whole-body hyperthermia will be evidenced. Well designed and performed early-stage correlative studies have the potential to strongly influence further clinical development of oncology clinical trials, and correlative data obtained from early stage trials has the potential to provide important guidance on the design and ultimate success of later stage trials. Blood samples will be collected for analysis of immunological panels (e.g. cytokines, chemokines), exosome research, RNA expression profiles. Urine will be collected for analysis of exosome research. The samples will be collected during different timepoints (before, during and after treatment). Citation Format: Ivana Gorbaslieva, Dana Mustafa, Robin Colenbier, Marc Peeters, Dirk Ysebaert, Vera Saldien, Luigi Brancato, Oleg Rudenko, Johan Van den Bossche, John Paul Bogers. First in-human, safety and preliminary efficacy study of (neo)adjuvant, model-based, whole-body hyperthermia treatment in advanced solid cancer patients or stage IV (TxNxM1) metastatic pancreatic adenocarcinoma patients: Liquid biopsies [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A023.

Introducing Protein Homeostasis and Glycogen Synthesis as Two Targets of Blue Light Radiation in Lentinula edodes.

Introduction: There are documents about the biological effects of blue light radiation on different organisms. An understanding of the molecular mechanism of radiation effects on biological samples is an important event which has attracted researchers' attention. Determining the critical dysregulated proteins of Lentinula edodes following blue light radiation is the aim of this study. Methods: 22 differentially expressed proteins of L. edodes in response to 300 lux of blue light were extracted from the related literature. Experimental, text mining and co-expression connections between the queried proteins were assessed via the STRING database. The maps were compared and the critical proteins were identified. Results: Among the 21 queried proteins, six individuals including heat shock HSP70 protein, 20S proteasome subunit, 26S proteasome subunit P45, Aspartate aminotransferase, phosphopyruvate hydratase, and phosphoglucomutase were highlighted as the critical proteins in response to blue light radiation. Conclusion: The finding indicates that protein homeostasis and glycogen synthesis are affected by blue light radiation. Due to the critical roles of proteins as enzymes and structural elements in life maintenance and involvement of glycogen synthesis in energy consumption, blue light radiation can be considered as a life promotional agent in future investigations.

Biological Effects of Low Dose Radiation (LDR) on Peri-Tumoral and Tumoral Areas with Squamous Cell Skin Cancer

<h3>Purpose/Objective(s)</h3> Low dose radiation (LDR) may have paradoxically beneficial effects via an adaptive response. We aimed to assess the adaptive response of healthy and malignant skin tissue to low doses of radiation and explore the molecular details behind the induced adaptive response. <h3>Materials/Methods</h3> We conducted a prospective, randomized pilot study (N=8) to ascertain the biological effects of integrating 0.1 Gy of LDR into standard radiotherapy sessions (2.0 Gy fractions) over the first two weeks of radiotherapy for patients 18-80 years of age (both sexes) diagnosed with squamous cell carcinoma of skin (lesions of 1 – 10 cm). Radiation treatment was done with a linear accelerator. The patients received definitive radiation for the tumor as determined by the treating physician using 2.0 Gy fractions. In addition, 0.1 Gy of LDR was integrated into the standard radiotherapy course on day 0 and day 6 over the first two weeks of treatment. Radiation delivery to healthy tissue was with a 1.5 cm margin around the tumor using a mask over the tumor. We obtained partial thickness skin biopsy samples of the tumor and peri-tumoral normal tissue before treatment from four patients (for control). An additional four patients (actively treated) were biopsied before and 24 hours after 0.1 Gy of LDR (day 0, 1 and day 6, 7). RNA was obtained from skin biopsies and processed for genetic expression (138K genes). <h3>Results</h3> The change in gene expression in healthy peri-tumoral tissues due to LDR exposure was relatively low (only 325 genes: 170 upregulated, 155 downregulated). The <i>senescence and autophagy in cancer</i> and <i>genotoxicity pathway</i> genes showed the most significant downregulation in peritumoral healthy tissue comparing days 0 and 1. The biological pathways in peritumoral healthy tissue comparing days 6 and 7 showed predominantly downregulation of genes with most pronounced downregulation seen in <i>electron transport chain in mitochondria</i> and genes involved in <i>non-alcoholic fatty liver disease</i>. In contrast to normal peritumoral tissue, the difference in gene expression in tumor tissue due to LDR exposure was significantly more pronounced (5,651 genes: 2,896 upregulated, 2,755 downregulated) The <i>allograft rejection</i> genes and <i>nuclear receptor meta-pathway</i> were the most upregulated in the tumoral tissues comparing days 0 and 1. The nuclear receptor meta-pathway were the most upregulated in the tumoral tissues on days 6 and 7. The <i>Allograft rejection pathway in skin cancer</i> was among those upregulated. <h3>Conclusion</h3> LDR had a modest effect on miRNA expression when applied to healthy peritumoral skin. Downregulated pathways predominate, and DNA repair mechanisms are stimulated by the first dose in healthy tissue. In contrast, a more pronounced effect on gene expression (as measured by miRNA profiles), including upregulation of several key relevant pathways, was induced by LDR to malignant tissue.

DNA damage induced by radiation exposure from cardiac catheterization – an analysis in patients and operators

Abstract Background The biological effects of low-dose radiation from cardiac imaging or intervention remain largely unknown. This study aimed to evaluate the effects of ionized radiation from cardiac catheterization on genomic DNA integrity and inflammatory cytokines in patients and operators. Methods Peripheral mononuclear cells (MNCs) were isolated from patients (n=52) and operators (n=35) before and after coronary angiography and/or percutaneous coronary intervention. Expression of gammaH2AX, a marker for DNA double-strand breaks, was measured by immunofluorescence. Dicentric chromosomes (DICs), a form of chromosome aberrations, were assayed using a fluorescent in situ hybridization technique. Results In the patient MNCs, the numbers of gammaH2AX foci and DICs increased after cardiac catheterization by 101±75% and 28±99%, respectively (P&amp;lt;0.05 for both). The mRNA expressions of interleukin (IL)-1α, IL-1β, leukemia inhibitory factor (LIF) and caspase-1 were significantly increased by radiation exposure from cardiac catheterization. The increase in IL-1β was significantly correlated with that of gammaH2AX, but not with dose area product. In the operators, neither gammaH2AX foci nor DICs level was changed, but IL-1β mRNA was significantly increased. Protein expression of IkappaBα was significantly decreased in both groups. Conclusions DNA damage was increased in the MNCs of patients, but not of operators, who underwent cardiac catheterization. Inflammatory cytokines were increased both in the patients and operators, presumably through activation of NF-kappaB. Further efforts to reduce radiation exposure from cardiac catheterization are necessary both for patients and operators. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grants-in-Aid for Scientific Research (KAKENHI)

Academic program recommendations for graduate degrees in medical physics: AAPM Report No. 365 (Revision of Report No. 197).

Academic program recommendations for graduate degrees in medical physics: AAPM Report No. 365 (Revision of Report No. 197).

Analysis of the miRNA expression profile of laboratory red crucian carp under low-dose caesium-137 irradiation.

Radiation can cause the differential expression of biological miRNA molecules. This research was based on the development of the laboratory red crucian carp (LRCC) to explore the feasibility of its application in the detection of low-dose ionizing radiation-induced biological damage in aquatic environments and the development of related molecular markers. Adult LRCC were irradiated with caesium-137 at 0.3 Gy, while RNA-seq and bioinformatics techniques were used to identify miRNAs that were differentially expressed relative to their levels in the nonirradiation group. Analysis of liver sections showed that liver cells in the radiation group showed nuclear pyknosis. In this study, 34 miRNAs differentially expressed in the liver of LRCC after irradiation were identified, among which seven were new crucian carp miRNAs; a total of 632 target genes were predicted in the prediction analysis. The results of comprehensive GO enrichment and KEGG pathway analyses showed that these target genes were mainly involved in energy transfer and material catabolism, especially malonyl-CoA biosynthesis, acetyl-CoA carboxylase activity, fatty acid biosynthesis and metabolism, and pyruvate metabolism; in addition, the AMPK signalling pathway was the most active pathway. This study shows that the LRCC is sensitive to radiation, or can be used as a candidate experimental animal to study the biological effects of radiation, and the screened miRNA can be used as a pre-selected biomarker for radiation damage detection and radiation biological environmental monitoring. CLINICAL TRIALS REGISTRATION: None.

Methodological Approaches to the Development of Criteria for the Diagnosis of Prepathological States by Psychophysiological and Medical-Biological Indicators

The purpose of the study was to investigate the problem of scientific rationale for approaches to early detection of prepathological conditions among different professional contingents. For this purpose, the role of biomedical and psychophysiological indicators was investigated based on the results of our own research works. Materials and methods. The method of assessing the risks of burnout was used to substantiate the role of psychophysiological indicators in determining prepathological states in workers of certain professions. The study was conducted using the Maslach Burnout Inventar (MBI-GS) questionnaire with subsequent statistical processing in the Jupiter Notebook environment. We used methods of logistic regression analysis and specialized software method “Eli-5”. To illustrate the mechanisms of action of medical-biological indicators the biological effects of electromagnetic radiation under conditions of low temperature were determined. The combined effect of these factors in a laboratory experiment for 30 days on the example of mature laboratory rats was studied. Results and discussion. The authors have proved that to effectively determine the risk groups for the development of professional burnout, it is advisable to use separate criterion-significant informative indicators using the Maslach Burnout-Inventar MBI-GS questionnaire. In addition, it is advisable to additionally determine the risks of developing burnout by the frequency of manifestations of symptoms of emotional exhaustion for the group of persons with prepathology. In order to prevent stress situational disorders among students when working with digital simulators, preliminary screening of emotional-stressful states with the subsequent application of psychocorrection measures is necessary. Modeling the complex effects of electromagnetic radiation and low temperatures made it possible to determine the features of the formation of biological effects in the body according to the criteria of physiological, morphological, immunological and biochemical changes. Thus, in the formation of the adaptive and immune response of the organism to the combined effect of these factors, the reduced temperature has a dominant share of the contribution. Conclusion. Our findings indicate that methodological approaches to the development of tools for the diagnosis of prepathological conditions, as the most effective element of primary prevention, should be based on the scientific basis of their structural elements. In the prevention of occupational diseases to the algorithm for determining the leading criteria for the recognition and differentiation of diseases at subclinical levels, it is advisable to include studies of a number of simple and effective medical-biological and psychophysiological indicators

Comparison of biological measurement and physical estimates of space radiation in the International Space Station

Nowadays, ordinary people can travel in space, and the possibility of extended durations in an environment such as moon of the Earth and Mars with higher space radiation exposures compared to past missions, is increasing. Until now, the physical doses of space radiation have been measured, but measurement of direct biological effects has been hampered by its low dose and low dose-rate effect. To assess the biological effects of space radiation, we launched and kept frozen mouse embryonic stem (ES) cells in minus eighty degree Celsius freezer in ISS (MELFI) on the International Space Station (ISS) for a maximum of 1,584 days. The passive dosimeter for life science experiments in space (PADLES) was attached on the surface of the sample case of the ES cells. The physical dosimeter measured the absorbed dose in water. After return, the frozen cells were thawed and cultured and their chromosome aberrations were analyzed. Comparative experiments with proton and iron ion irradiation were performed at particle accelerators on Earth. The wild-type ES cells showed no differences in chromosomal aberrations between the ground control and ISS exposures. However, we detected an increase of chromosome aberrations in radio-sensitized histone H2AX heterozygous-deficient mouse ES cells and found that the rate of increase against the absorbed dose was 1.54-fold of proton irradiation at an accelerator. On the other hand, we estimated the quality factor of space radiation as 1.48 ± 0.2. using formulas of International Commission of Radiation Protection (ICRP) 60. The relative biological effectiveness (RBE) observed from our experiments (1.54-fold of proton) was almost equal (1.04-fold) to the physical estimation (1.48 ± 0.2). It should be important to clarify the relation between biological effect and physical estimates of space radiation. This comparative study paves a way to reveal the complex radiation environments to reduce the uncertainty for risk assessment of human stay in space.

Erythemal UV radiation across Nigeria: where do we stand?

The deleterious effects of solar ultraviolet (UV) radiation on humans are of public health concern which demands constant global monitoring and intervention. This study analysed the latitudinal variations in mean daily and multi-year erythemal ultraviolet radiation (EUVR) across 7 states in Nigeria using satellite data from the Total Ozone Mapping Spectrophotometer (TOMS) and Ozone Mapping Instrument (OMI). The latitudes studied were 13° N, 8° N, 6° N and 4° N respectively, using 37 years of data obtained from phases: 1979–1988, 1989–1998, 1999–2008 and 2009–2020. The data obtained were statistically analysed using Ms Excel and MATLAB. The results of this study show that the mean daily EUVR at the selected latitudes ranges from 32.97 to 390 (mW/m2). The results show that Borno State located at latitude 13° N had the highest EUVR, while Rivers State recorded the least EUVR at latitude 4° N. Comparative analysis of all the locations studied indicates latitudinal and longitudinal variations because the eastern axis recorded higher values than its western counterpart on the same latitude. Box and whisker plots in this study summarized the latitudinal variance in the mean multi-year EUVR in each phase. Box and whisker plots from 2009–2020 showed that there was a drastic reduction in mean multi-year EUVR in this phase unlike in the other phases. The findings of this study when compared to the UV index show that the 37 years mean EUVR obtained across Nigeria ranged from 8–10 which is on the “very high” category. This study recommends the implementation of WHO suggestions in preventing the biological effects of solar UV radiation. Furthermore, the Nigerian government should curb ignorance among its citizens by heightening public awareness of the effects of EUVR.

Development of novel crystal scintillators for lunar surface science

The development of novel crystal scintillators for a lunar landed mission near future is reported. On that mission, we aim to assess the radiation dose, biological effect, water, and other resources on the lunar surface. To accomplish this, a Lunar Vehicle Radiation Dosimeter (LVRAD) made up of several radiation detectors has been proposed. New scintillation crystals are being developed for neutron and gamma measurements. Stilbene and undoped LaCl3 crystal were selected for fast neutron/gamma spectrometers. The mutual combination of organic and inorganic detectors benefits from direct fast neutron detection via 35Cl(n, p)35S reaction as well as the good gamma resolution of LaCl3 and the high detection efficiency of stilbene. LaCl3 crystals with the diameter of 38.1 mm were grown by a homemade modified Bridgman furnace. For epithermal neutron spectrometer, 6LiI:Ag crystal was selected due to its pulse shape discrimination capability and highest detection efficiency in terms of size for both thermal and epithermal neutron among scintillation materials. Enrich 6LiI was purified using the zone-refining technique. The crystal was then grown by the same Bridgman furnace.

TOPAS-nBio simulation of temperature-dependent indirect DNA strand break yields

Current Monte Carlo simulations of DNA damage have been reported only at ambient temperature. The aim of this work is to use TOPAS-nBio to simulate the yields of DNA single-strand breaks (SSBs) and double-strand breaks (DSBs) produced in plasmids under low-LET irradiation incorporating the effect of the temperature changes in the environment. A new feature was implemented in TOPAS-nBio to incorporate reaction rates used in the simulation of the chemical stage of water radiolysis as a function of temperature. The implemented feature was verified by simulating temperature-dependent G-values of chemical species in liquid water from 20 °C to 90 °C. For radiobiology applications, temperature dependent SSB and DSB yields were calculated from 0 °C to 42 °C, the range of available published measured data. For that, supercoiled DNA plasmids dissolved in aerated solutions containing EDTA irradiated by Cobalt-60 gamma-rays were simulated. TOPAS-nBio well reproduced published temperature-dependent G-values in liquid water and the yields of SSB and DSB for the temperature range considered. For strand break simulations, the model shows that the yield of SSB and DSB increased linearly with the temperature at a rate of (2.94 ± 0.17) × 10−10 Gy–1 Da–1 °C–1 (R 2 = 0.99) and (0.13 ± 0.01) × 10−10 Gy–1 Da–1 °C–1 (R 2 = 0.99), respectively. The extended capability of TOPAS-nBio is a complementary tool to simulate realistic conditions for a large range of environmental temperatures, allowing refined investigations of the biological effects of radiation.