Background: Ramsar (Mazandran province) is known for its extremely high levels of natural background radiation. Although no excess cancer rate is reported in these areas by epidemiological studies, the study of tumor markers in the inhabitants of these areas may shed some light on the impact of high levels of background radiation on cancer induction. Materials and Methods: The level of backgrou...

An extensive study was undertaken to Investigate on the overall film badge service performance with which occupational radiation, exposures are reported In Iran, The study involved the analysis of film badges exposed to x-and gamma rays and beta particles. For test exposures, x-rays between 60 and 140 KVPCo-60 gamma radiation and Sr-90 beta particles were used. The actual delivered dose equival...

In the discussion that follows, we assume that gamma rays are the radiation of interest. The principles discussed also apply to monoenergetic x rays; in many cases of concern in x-ray shielding, however, the photons are produced in the bremsstrahlung process that yields a wide and continuous distribution of photon energies. Specialized shielding approaches have been developed to carry out shiel...

The tripeptide glutathione (L-y-glutamyl-L-cysteinylglycine) (GSH) is the predominant low-molecular-weight thiol in many organisms and has been proposed to protect cells from oxidative damage such as that formed by H202 and ionizing radiations (19). Escherichia coli deficient in GSH because of mutations in the gshA gene was found previously (3) to exhibit normal resistance to X irradiation in t...

background: astronauts will be exposed to both chronic space radiation and acute high doses of energetic radiation of solar particle events in long-term deep space missions. the application of radioprotectors in space missions has basic limitations such as their very short time window as well as their acute toxicity and considerable side effects. the aim of the present study was to investigate ...

To improve the radiation resistance of Yb-doped fiber lasers, we investigate influence pre-radiation and photo-bleaching on gamma-radiated laser’s performance. When gamma dose is within 10 krad(Si) with a rate less than 0.4 rad(Si)/s, compared to output power non-pre-radiated laser, technique could enhance against gamma-ray. However, mode instability threshold was decreased, which caused by cum...

The basidiomycetous fungus Cryptococcus neoformans has been known to be highly radiation resistant and has been found in fatal radioactive environments such as the damaged nuclear reactor at Chernobyl. To elucidate the mechanisms underlying the radiation resistance phenotype of C. neoformans, we identified genes affected by gamma radiation through genome-wide transcriptome analysis and characte...

Background: H2AX is a histone variant that is systematically found and ubiquitously distributed throughout the genome. DNA double-strand breaks (DSBs) induce phosphorylation of H2AX at serine 139 (γH2AX), an immunocytochemical assay with antibodies recognizing γH2AX has become the gold standard for the detection of DSBs. The importance of this assay to investigate different individu...

Chinese hamster ovary cells transformed with a hybrid expression plasmid containing both the murine interferon-gamma (MuIFN-gamma) and the murine dihydrofolate reductase-coding sequences were subjected to selection in stepwise increasing concentrations of methotrexate. By this procedure the production rate of MuIFN-gamma was increased from an initial level of approximately 20,000 to approximate...

Background: High density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. Over the past eight years, some efficient galena-based concrete samples for shielding X or gamma rays was produced. The goal of this study was to produce a novel high density concrete against neutron and photon radiations using tourmaline and galena. Materials an...