最新刊期
期 4 ， 2018
- 摘要：To study the radio frequency electromagnetic exposure security of a driver from the subway wireless communication system, the subway cab's RF electromagnetic environment model was established, which was radiated by the antennas of the wireless communication system using a three-dimensional high frequency structure simulator (HFSS). The simulated results of electric field strength distribution in the driver's cab were between 0.005 and 0.118 V/m. The power level of the wireless communication system antenna's signal was measured to be between -54.91 and -30.22 dBm using the electric field strength analyzer, and the electric field intensity in the subway driver's cab was estimated to be in the range of 0.006~0.109 V/m, which is consistent with the simulation results. Thus, the computational reliability of the HFSS electromagnetic simulation software was verified. The absorbed dose in the electromagnetic environment was simulated separately for the standing and sitting posture of the driver's human model on the above basis. The simulation results showed that the peak values of the average specific absorption rate for sitting posture and standing posture were 3.838 3×10-7 W/kg and 3.118 7×10-7W/kg respectively; peak values of electric field intensity for sitting and standing posture were calculated to be 0.12 V/m and 0.11V/m respectively; the peak values of magnetic field strength for sitting posture and standing posture were respectively 7.586 8×10-4A/m and 7.276 7×10-4 A/m. The results obtained for the various peak values were all within the electromagnetic occupational exposure restriction limit, created by the International Commission on Non-Ionizing Radiation Protection(ICNIRP). Thus, this investigation demonstrated that the RF electromagnetic radiation environment in the subway cab was indeed safe for the driver.关键词：Antenna of wireless communication system;High frequency structure simulator;Radio frequency electromagnetic radiation of subway;Occupational electromagnetic exposure of subway driver
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发布时间：2021-12-10
RADIATION PROTECTION
- 摘要：Using published metrology methods and the CiteSpaceV software, we obtained data from the Web of Science and CNKI databases and conducted quantitative and systematic analysis of relevant literature, authors, journals, institutions, and keywords in the field of radiation bystander effects. The results showed that the research hotspots in the past 10 years were heavy ions in connection with apoptosis and gene instability in cancer occurrence and radiation protection, and most of the results were published in foreign journals, such as Cancer Research and Radiation Research. Meanwhile, the journals such as Radiation Protection Bulletin and Journal of Radiation Research and Radiation Processing were the two most important publications in China. The major foreign authors were Mothersill C and Prise K M, while the major domestic author was SHAO Chunlin. In addition, the most important research institutions at home and abroad were the Chinese Academy of Sciences and Canadian Macmaster University, and the main document-issuing country was the United States. These findings indicate that research on radiation bystander effects mainly focuses on radiation protection and cancer treatment. Identifying the important literature, authors, and institutions in this field will help achieve more breakthrough results.关键词：Radiation-induced bystander effects;Bystander effects;Bibliometrics
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发布时间：2021-12-10
RADIATION INTERDISCIPLINARY RESEARCH
- 摘要：To identify a-particles and protons using CR-39 solid state nuclear track detector (CR-39 SSNTD), track growth model and interaction theory between particles and media were applied and the profile and appearance of the tracks produced by α-particles and protons on the CR-39 SSNTD were simulated. In addition, the optimal chemical etching conditions for 3~8 MeV α-particles and 1~9 MeV protons were calculated. The corresponding diameters, depths and the gray level values of the tracks for the optimal chemical etching conditions were simulated to identify the α-particles and protons with the same energy and different energies. To verify the simulation method, a CR-39 SSNTD was used to measure the tracks made by 5.84 MeV α-particles and 3 MeV protons. The differences between the experimental and simulated diameters of the tracks ranged between 0.36%~9.70%. For the optimal etching conditions obtained from simulation, a difference of 5.6% was observed between the experimental and simulated chemical etching time. These results are preliminary proof of the feasibility and validity of the simulation method.关键词：CR-39;Solid state nuclear track detector;Etching conditions;α-particle;Proton
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发布时间：2021-12-10
RADIATION TECHNOLOGY APPLICATION
- 摘要：Ninety-six mice aged 3 weeks were randomly divided into two groups: a group exposed to electromagnetic pulse (EMP) at 200 kV/m in 400 pulses for 30 d, 2 h/d, and a sham-exposure group. The body weights were measured during the exposure time. The testicular index; sperm count, sperm deformity rate, spermatogenic cells apoptosis; and metastasis tumor antigen 1 (MTA-1) protein and mRNA expression in testicles were measured at 1-, 7-, 14-, 21-, 30-, and 60-day time points after exposure. The results showed that body weights in the exposure group were significantly lower than those in the sham-exposure group on days 8~28 of EMP exposure (p < 0.05); compared with that in the sham-exposure group, testicular index in the exposure group decreased significantly on days 21~60 after exposure; sperm count decreased on days 7~60 after exposure; the rate of sperm deformation increased on days 1~30 after exposure; apoptotic spermatogenic cells increased on days 1 and 60 but decreased on days 7 and 14 after exposure (p < 0.05); MTA-1 protein expression in testicles decreased significantly at all time points after exposure; and mRNA expression decreased on days 1~21 after exposure. The reduced testicular indexes and sperm quality, as measured by the decreases in MTA-1 protein and mRNA, suggest that EMP exposure inhibits the development of testicles in growing male mice.关键词：Electromagnetic pulse (EMP);BALB/c mice;Testicle;Sperm;Metastasis tumor antigen 1 (MTA-1)
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发布时间：2021-12-10 - 摘要：Protein named AP with the molecular weight of 18.33 kDa was purified from prepared slices of Angelica sinensis using 80% ammonium sulfate precipitation and Sephadex G-50 gel filtration chromatography. A mouse model of acute radiation injury was then established via whole-body irradiation with X-rays at a dose of 6 Gy. The radioprotective effects of Angelica sinensis protein AP were evaluated using amifostine as a control by measuring body weight, peripheral blood leukocyte count, thymus index, spleen index, colony forming unit-spleen (CFU-S), morphology and histopathology of the spleen, and splenic antioxidant enzyme activity in the irradiated mice. The results showed that AP significantly increased the number of peripheral blood leukocytes, thymus index, spleen index, CFU-S, and catalase activity in irradiated mice by 135%, 103%, 23%, 219%, and 180%, respectively, and kept the number of splenic white pulp, resulting in a significant 94% reduction in weight loss. These results indicate that the Angelica sinensis protein AP has radioprotective effects on mice.关键词：Angelica sinensis protein;X-rays;Radiation protection;Mice
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发布时间：2021-12-10 - 摘要：To explore the radioprotective effect of Saccharomyces cerevisiae-derived-beta-D-glucan (BG) on human umbilical vein endothelial cells (Eahy926), cytotoxicity of BG on Eahy926 cells was detected by 3-(4, 5- Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), and the optimum concentration and pretreatment time were confirmed (10 μg/mL, 24 h). The clone formation assay was used to detect the BG effect on radiosensitivity of Eahy926 cells. At 0.5 h and 24 h after X-ray irradiation at a absorbed dose of 2 Gy, the apoptosis, DNA damage, and intracellular reactive oxygen species (ROS) of Eahy926 cells in each group were measured through flow cytometry, and the enzyme activities of superoxide dismutase (SOD) and catalase (CAT) were also detected. The results showed that BG was non-toxic to Eahy926 cells. BG pretreatment could decrease the cell damage caused by X-rays and significantly increase clone survival rates. At 0.5 h and 24 h after irradiation, the DNA damage, cell apoptosis rates, and intracellular ROS level of the BG pretreatment group were significantly lower than those of the 2 Gy group, and the enzyme activities of SOD and CAT were higher than those of the 2 Gy group. At 0.5 h and 24 h after irradiation, the repair rates of DNA damage in the BG pretreatment group were higher than those in the 2 Gy group. The results indicate that BG has a radioprotection effect on Eahy926 cells, and the mechanism may be attributed to BG's effect on scavenge of ROS, enhancement of antioxidase activities, reduction of DNA damage and cell apoptosis, and promotion of the repair of DNA damage.关键词：Saccharomyces cerevisiae-derived-beta-D-glucan;X-ray irradiation;Human umbilical vein endothelial cell (Eahy926);Radioprotection
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发布时间：2021-12-10
RADIOBIOLOGY AND RADIOMEDICINE
- 摘要：A Co-irradiation process was employed for antibacterial finishing of cotton fabrics using an N-halamine antiseptic, (3-acrylamidopropyl) trimethylammonium chloride (AAPTAC), as the monomer. The effect of the absorbed dose on the chlorine content and breaking strength were studied. The results showed that the chlorine content and breaking strength of the treated fabrics increased and decreased, respectively, with the increasing absorbed doses. Fourier transform infrared spectroscopy (FTIR) proved that AAPTAC was successfully grafted onto the cotton fiber. Scanning electron microscopy showed that the surfaces of the Co-irradiated process-treated cotton fabrics were covered by layers. When the absorbed dose was 43.3 kGy, the treated cotton fabrics after chlorination could kill 100% of Staphylococcus aureus and Escherichia coli O157:H7 within 5 min of contact time.关键词：Electron beam irradiation;(3-Acrylamidopropyl)trimethylammonium chloride;Cotton fabrics;Antibacterial finish
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发布时间：2021-12-10 - 摘要：Herein, silver nitrate, oxidized multiwall carbon nanotube (o-MWCNT), and graphene oxide (GO) were used to synthesize silver/oxidized multiwall carbon nanotube/reduced graphene oxide (Ag/o-MWCNT/rGO) nanocomposites in aqueous solution by one-step gamma radiation-induced reduction at room temperature. Scanning electron micrograph, transmission electron micrograph, X-ray diffraction spectrogram, Raman spectrum, ultraviolet-visible absorption spectrum, and X-ray photoelectron spectroscopy confirmed that the structure of Ag/o-MWCNT/rGO nanocomposite prepared under the optimized condition was flower-like, in which GO was reduced to rGO by gamma-irradiation. Nano-silver was dispersed uniformly in the nanocomposite with an average diameter of ~102 nm. The introduction of o-MWCNT can increase the interlayer spacing of GO and overcome its restacking, leading to the formation of conductive networks. We decorated the o-MWCNT/rGO with nano-silver, to improve the electromagnetic interference (EMI) shielding effectiveness (SE) of nanocomposites. Ag/o-MWCNT/rGO nanocomposite with high EMI SE will be an attractive candidate for EMI shielding purpose.关键词：Nano-silver;Oxidized multiwall carbon nanotube (o-MWCNT);Reduced graphene oxide (rGO);Radiation-induced reduction;Electromagnetic interference (EMI) shielding
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发布时间：2021-12-10
RADIATION CHEMISTRY
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