最新刊期
      期 6 ， 2007
      • DING Guirong,GUO Guozhen
        Vol. 25, Issue 6, Pages: 321-325(2007)
        摘要：A review of the application in nuclear accidents and recent advances in research of radioprotectants is presented here. The characters, pharmacological effects and side effects of six classification of radioprotectants including sulfhydryl compounds, cytokines, hormones and Chinese traditional medicines were reviewed as well as the perspective in this field.  
        关键词：Radiation injury;Radioprotectant;Sulfhydryl compounds   
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        发布时间：2023-03-30
      • GUO Jinxue,XIN Xueqiong,ZHU Ying,LI Wenxin
        Vol. 25, Issue 6, Pages: 326-329(2007)
        摘要：Multi-walled carbon nanotubes (MWNTs) irradiated with γ-rays were chemically modifified with glucosamine and decylamine, respectively. The cytotoxicity of Tetrahymena pyriformis exposured to irradiated MWNTs, MWNTs modifyed with glucosamine and decylamine (denoted by G-MWNTs and D-MWNTs) was carried out. The results indicated that MWNTs modified with different functional groups exhibited different bioactivity to Tetrahymena pyriformis. D-MWNTs showed a significant toxicity to Tetrahymena pyriformis, and the viability of cells reduced to 46.2%. And G-MWNTs promoted significantly the growth of cells, with the viability being up to 308%. More interestingly, it was shown that the toxicity and bioactivity of modified MWNTs to cells was changed along with the contents of functional groups bound on the surface of MWNTs. The studies may supply a possible strategy for enhancing or reducing the toxicity of MWNTs to meet certain applications in biological and medical field.  
        关键词：Multi-walled carbon nanotubes (MWNTs);γ-rays;Modification;Toxicity;Tetrahymena pyriformis   
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        发布时间：2023-03-30
      • CHEN Yongkang,ZHOU Ruimin
        Vol. 25, Issue 6, Pages: 330-335(2007)
        摘要：In this paper, micro-porous array on polypropylene membranes were successfully prepared by electron-beam irradiation, before which the membrane were covered with mask and then etched with oxidation solution after which. The aperture of the prepared membranes was about 200 µm. GPC DSC XRD was used to measure the molecular weight, to characterize the thermal properties and the crystallinity of the irradiated crystal polymer respectively. The effect of etching time, temperature and the concentration of solvent on the etching rate also was investigated. The mechanical properties of irradiated and etched membranes at different irradiation doses were determined by use of electronic tensile testing machine and the pattern morphology as well as aperture of the prepared micro-porous array membranes were characterized by electron microscope.  
        关键词：Electron-beam irradiation;Polypropylene (PP);Etching;Micro-porous array   
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        发布时间：2023-03-30
      • LI Zhenzhong,HE Wei,MA Yalin,GUO Hongjun,ZHANG Wenxiong
        Vol. 25, Issue 6, Pages: 336-340(2007)
        摘要：Maleic anhydride (MAH) and styrene (St) grafted onto polypropylene (PP) were prepared by UV irradiation. Effects of the irradiation time, monomer and initiator content on the grafting rate and melt flow rate (MFR) were studied. The results show that the optimal duration of UV irradiation is 30s. The grafting rate increases with initiator content when initiator content less than 0.6 phr, the MFR value of grafted PP reaches the highest point when benzophenone (BP) content is 0.4 phr. The content of MAH and St have an effect on the grafting rate and MFR value of the grafted PP, and the optimal contents of monomer is 4 phr. The existence of St as a co-monomer reduces apparently the MFR value of grafted PP greatly. Grafted PP present significant changes in crystallization and fusion peaks, indicating differences in crystal size and formation after grafting reaction.  
        关键词：Maleic anhydride;Styrene;UV irradiation;Grafting;Polypropylene   
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        发布时间：2023-03-30
      • YANG Guang,TANG Zhuo,HUANG Pengcheng
        Vol. 25, Issue 6, Pages: 341-344(2007)
        摘要：A UV-curable cationic silicon-containing epoxy resin formulation was developed. The gel conversion of the cured resin after 10-min UV irradiation reached 80% in the presence of 5% diaryliodonium salt photoinitiator and 5.5% polyol chain transfer agent by cationic ring-opening polymerization. The glasscloth-reinforced composites were fabricated with the silicon-containing epoxy resin using the wet lay-up technique and UV irradiation. The mechanical properties of the composites were evaluated. Compared with glass cloth reinforced bisphenol A epoxy resin matrix composites, the silicon-containing epoxy resin matrix composites possessed higher tensile strength and interlayer shear strength which was 158.5MPa and 9.9MPa respectively while other mechanical properties such as flexural property and tensile modulus were similar.  
        关键词：Epoxy resins;Silicones;Cationic polymerization;UV-curing;Resin matrix composites;Mechanical properties   
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        发布时间：2023-03-30
      • WU Xinfeng,LI Hongbin,HAO Xufeng,ZHOU Fei,DENG Bangjun,FEI Shunting,ZHOU Ruimin
        Vol. 25, Issue 6, Pages: 345-349(2007)
        摘要：Polyimide (PI) film etched by electron beam (EB) to produce PI micron-hole separation membrane combined with the methods of masks and oxygenation corrosion was studied in this paper. The effect of the absorbed doses, corrosion time and corrosion temperature on the corrosion speed of irradiated PI were discussed. The results showed that the corrosion speed of irradiated PI grew up with increasing the corrosion temperature, corrosion time and absorbed dose gradually. The analysis of infrared spectroscopy (IR) indicated that the main chain of PI molecules was broken by EB to certain extent. It meant the molecule weight of PI turned small and PI film was eroded easily by oxidation solution. In the EB etching process, a piece of lead mask with micron-holes was covered on the PI film and was etched by EB. And then the irradiated PI film was eroded by the solution of H2SO4 and K2Cr2O4. A piece of PI micron-hole separation membrane was gained by this technology.  
        关键词：Electron beam(EB);Polyimide (PI);Erode;Separation membrane;Etch   
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        发布时间：2023-03-30
      • LIU Yuguang,HUANG Yudong,HOU Jing,GAO Deyu,ZHANG Xuequan
        Vol. 25, Issue 6, Pages: 350-354(2007)
        摘要：Fully vulcanized polybutadiene rubber particles (FVBR) were prepared by polybutadiene latex (PBL) vulcanization induced by 60Co γ-rays irradiation, and the effect of absorbed dose on crosslinking behavior was studied. Mean diameter, diameter distribution and morphology of the particles in the PBL irradiated at different doses as well as in the FVBR were characterized by laser particle analyzer and AFM. The crosslinking effect on the mechanical properties of the films, by casting from PBL at different doses correspondingly, was evaluated by mechanical and dynamic mechanical analysis (DMA) respectively. The results showed that the diameter and swelling property decreased with absorbed dose, while crosslink density and gel fraction increased. Moreover, the decrease of the tensile strength and elongation at break, the increase of the hardness in shore A and young’s modulus (E), and the increase of storage modulus (E′) and narrowing of loss tangent peak (Tan δ) were all accounted for the increment of crosslinking. The Charlesby-Pinner equation fits well with the PBL vulcanization in the range of absorbed doses from 0 to 200kGy.  
        关键词：Radiation crosslinking;Vulcanization;Polybutadiene latex   
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        发布时间：2023-03-30
      • PENG Chaorong,CHEN Hao,WANG Xiuying,ZHOU Xuemei,CHEN Zhuping,DENG Huachuan,WANG Jingxia
        Vol. 25, Issue 6, Pages: 355-358(2007)
        摘要：Ultra-high molecular weight polystyrene (UHMPS) was prepared by emulsion polymerization initiated with gamma ray. The effects of reaction conditions on conversion and molecular weight of polystyrene was investigated. UHMPS was characterized by means of gel permeation chromatography (GPC), Fourier transform infrared spectrometer (FT-IR), nuclear magnetic resonance (1HNMR) and differential scanning calorimeter (DSC). The results show that the weight-average molecular weight (Mw) of polystyrene (PS) which was synthesized at the dose rate of 0.6Gy/min is up to1.63×106, molecular weight distribution is 2.88 and Tg is 78℃.  
        关键词：Ultra-high molecular weight polystyrene;Irradiation;Emulsion polymerization   
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        发布时间：2023-03-30
      • DONG Xicun,LI Wenjian,HE Jinyu,LIU Qingfang,YU Lixia,ZHOU Libin,QU Ying,XIE Hongmei
        Vol. 25, Issue 6, Pages: 359-362(2007)
        摘要：To improve biological output, sugar Brix and resistance to adversities, the dry seeds of Sweet Sorghum, "BJ0601" and "BJ0602" ,were irradiated by 12C+6 ion beam offered by Heavy Ion Accelerator in Lanzhou with different doses. The current results showed as follows: (1) The survival fraction of sweet sorghum presented "saddle like model" that the survival rate decrease, then increase and decrease further again with increase of irradiation doses; (2) Compared with the control, the stalk output per mu (667 m2) and sugar Brix showed obvious changes with the changes of irradiation doses; (3) Mutational spectra, including plant height, stem weight per plant, stalk diameter, sugar Brix, early maturity, were selected after irradiation. Based on these results, further studies of the variety breeding and mutation mechanism are needed.  
        关键词：Sweet sorghum;12C+6 ion beam;Mutation breeding   
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        发布时间：2023-03-30
      • JIA Rongfei,CHEN Honghong,YU Lei,ZHAO Meijia,SHAO Chunlin,CHENG Wenying
        Vol. 25, Issue 6, Pages: 363-367(2007)
        摘要：The bystander effects induced by continuous low-dose-rate (LDR) 125I seeds radiation on damage of human lung cancer cells were investigated. Human adenocarcinoma cell line A549 and human small cell lung cancer cell line NCI-H446, which have different sensitivities to high-dose rate (HDR) external irradiation, were exposed directly to 125I seeds in vitro and co-cultured with unirradiated cells for 24 h. Using cytokinesis-blocking micronucleus method and γ H2AX fluorescence immunoassay, bystander effects induced by 2Gy and 4Gy 125I seed irradiation on micronucleus formation and DNA double-strand breaks (DSBs) of human lung cancer cells were detected and evaluated. The results showed that irradiation with 125I seeds can induce medium-mediated bystander effects in A549 cells and NCI-H446 cells, exhibiting that both micronuclei formation and γ H2AX focus formation in bystander cells were increased significantly compared with non-irradiated cells. The extent of DNA damage induced by bystander effects was correlated with accumulated radiation dose and radiosensitive of tumor cells. NCI-H446 cells that were sensitive to HDR γ irradiation were more sensitive to continuous LDR irradiation and bystander effects than A549. However, a comparison between the bystander effects and direct effects elicits the intensity of bystander responses of A549 cells was higher than that of NCI-H446 cells. A dose-related reduction in bystander responses was observed both in A549 cells and NCI-H446 cells, suggesting that the signaling factors involved in the bystander signaling pathways may decrease with the increase of cell damages.  
        关键词：125I seeds;Bystander effects;γ H2AX;Micronuclei;Human lung cancer cells   
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        发布时间：2023-03-30
      • XIE Yi,ZHANG Hong,DANG Bingrong,HAO Jifang,GUO Hongyun,WANG Xiaohu
        Vol. 25, Issue 6, Pages: 368-370(2007)
        摘要：For estimating biological risks from low doses continual irradiation, we investigated the effects of exposure to continuously fractionated X-rays on murine immune system. The BALB/c mice were irradiated with 0.07Gy at the first day and 0.08 Gy/d in the following 12 days at a dose rate of 0.2 Gy/min. The peripheral blood lymphocyte cycle and death were determined by flow cytometry at the cumulative doses of 0, 0.07, 0.23, 0.39, 0.55, 0.71, 0.87 and 1.03 Gy respectively. The results showed that the cycle of peripheral blood lymphocyte was arrested in G0/G1 at cumulative doses of 0.07, 0.23, 0.71 and 0.87 Gy, and in G2/M at cumulative doses of 0.39 and 1.03 Gy; the percentage of death of peripheral blood lymphocyte was ascended with dose increasing, and reached the death peak at cumulative doses of 0.71 Gy. The results suggested that low doses continual X-rays total-body irradiated could result in changes of cellular cycle and death, and some damages to immunocytes, which accorded to linear square model.  
        关键词：Low-dose continuously fractionated X-rays irradiation;Peripheral blood lymphocyte;Cellular cycle and death;Mice   
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        发布时间：2023-03-30
      • YU Long,AN Xiao
        Vol. 25, Issue 6, Pages: 371-374(2007)
        摘要：In order to compared the mutagenic effects of the validamycin producing the strain (Streptomyces hygroscupicus var. Jingganggensis Yen.) was implanted with two kinds of ion sources. The results showed that when two kinds of ion sources implanted into the strain by turns, more positive mutants and higher yield would be acquired. Using this method, a high-yielding strain B1-3 was obtained, which produce the titer of validamycin A of 21514, and was 54.4% higher than that of the original strain.  
        关键词：Ion implantation;Mutation;Validamycin;Jinggangmycin   
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        发布时间：2023-03-30
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