最新刊期
      期 2 ， 2006
      • CHEN Jinhua,Masaharu Asano,Yasunari Maekawa,Masaru Yoshida
        Vol. 24, Issue 2, Pages: 65-71(2006)
        摘要：Polymer electrolyte membrane (PEM) is a key material that strongly affects the cell performance, cost and application prospect of the PEM fuel cell. The membrane acts as a separator to prevent mixing of the reactant gases and as an electrolyte for proton transportation. Radiation-grafted PEM has a special chemical structure, composing of fluorinated main chains and sulfonated side chains. The main chain acts as a stable backbone that gives the necessary strength, dimensional stability and gas barrier while the side chain gives the ability of proton transportation. In our study, the suitability of some base films, monomers and crosslinkers, as well as the preparation processes have been investigated in detail in order to develop a high performance radiation-grafted PEM.  
        关键词：Radiation grafting;Polymer electrolyte membrane;Fuel cell   
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        发布时间：2023-03-30
      • ZHOU Dunbai,JIA Demin,HUANG Xianbo
        Vol. 24, Issue 2, Pages: 72-76(2006)
        摘要：The advances in radiation processing of flame-retardant (FR) polymers are reviewed in this paper. People pay more attention to the R and D on FR materials for the sake of environment protection. Radiation-induced crosslinking effects in polymeric materials have been used to produce low halogen and halogen-free FR polymers, which are applied in a number of industries.  
        关键词：Radiation;Halogen-free flame-retardant;Cross-linking;Cure;Graft   
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        发布时间：2023-03-30
      • SU Jielong,WU Guozhong,ZENG Hongyan
        Vol. 24, Issue 2, Pages: 77-82(2006)
        摘要：Fluorocarbon finishing agents were prepared by γ-ray initiated emulsion polymerization of fluorine-containing acrylates at different doses. Copolymerization of the fluorocarbon monomer and butyl acrylate was also studied. Morphology and size distribution of the emulsion particles were investigated by transmission electron microscopy and dynamic light scattering, respectively. Influence of fluorine-containing monomer on water and oil repellency property of final products was discussed. It was found that conversion of the dodecafluoroheptyl methacrylate was 98% at 5kGy and hexafluorobutyl acrylate was fully polymerized at 10kGy. Water repellency of the emulsion product derived from dodecafluoroheptyl methacrylate was Grade six and the oil repellency was Grade three.  
        关键词：Radiation;Emulsion polymerization;finishing agents   
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        发布时间：2023-03-30
      • KANG Bin,QI Zhiqiang,WU Yajun,TANG Xiaobin,CHANG Shuquan,ZHANG Peigen,FANG Meihua,DAI Yaodong
        Vol. 24, Issue 2, Pages: 83-86(2006)
        摘要：Water-soluble chitosan oligomers with different molecular weight were prepared by a γ-ray degradation method. Effects of irradiation conditions on the chitosan degradation, molecular weight of the irradiated chitosan and yield of the water-soluble products were studied. Gd value of the chitosan radiation degradation was calculated, and mechanisms of the degradation were discussed. Gel permeation chromatography, Fourier transform infrared spectroscopy and ultraviolet-visible spectrometry (UV-VIS) were applied to characterized and analyzed the degradation products. The results indicated that molecular weight of the degraded chitosan decreased remarkably and its chemical structure changed. It was considered that OH radical is vital to the radiation degradation of chitosan.  
        关键词：Chitosan;Radiation degradation;Water-solubility;Molecular weight;Chemical structure   
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        发布时间：2023-03-30
      • LEI Zhongli,BI Shuxian
        Vol. 24, Issue 2, Pages: 87-90(2006)
        摘要：The chelating fiber containing amidoxime group has been synthesized by graft copolymerization of acrylonitrile (AN) onto Poly (vinyl formal) Fiber (PVF) after electron-beam (EB) preirrradiation. The article systematically studies the influence factors of grafting rate. Such as absorbed does, reaction temperature and time, monomer concentration. Optimum grafting result could be achieved by irradiating the PVF to 300kGy and reacting for 1 hours at 70℃ with 10% monomer concentration of AN, while adding 0.05mol/L H2SO4 and Mohr’s salt of 0.1w%. The structure of the chelating fiber has been indicated by FT-IR and revealed the total grafting rate which varied with several factor.  
        关键词：Electron-beam irradiation;Grafting;Amidoxime chelating fiber;Acrylonitrile (AN)   
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        发布时间：2023-03-30
      • LI Linfan,XIE Leidong,ZHANG Yan,FU Haiying,ZHANG Fengying,SHENG Kanglong
        Vol. 24, Issue 2, Pages: 91-96(2006)
        摘要：The effect of SBS irradiated with 60Co γ-rays at ambient temperature was studied in this article. SBS before and after irradiation were characterized by means of Fourier-transform infrared spectroscopy(FT-IR), differential scanning calorimetry (DSC), thermal gravimetric analysis(TG), scanning electron microscopy(SEM), and dynamic shear rheology(DSR). Almost no oxidation substance product was found in FT-IR spectra of the irradiated SBS. Cross-linking reaction occurred after SBS irradiation, and with increasing doses, the mass ratio of indiscerptible content in toluene developed. The analysises of DSC and TA indicated that Tg of the flexible segment PB and rigid part PS shifted to a high temperature to some extent. A higher Tg of about 120℃ came into being and the substance of resisting high temperature increased. According to DSR analysis, a network relaxation was observed after irradiation. The higher the irradiation dose was, the more obvious the peak value of tan δ was. In addition, the shearing viscosity and the storage modulus G’ became larger and the loss modulus G’’ became smaller than those before irradiation. Temperature sensitivity of the irradiated SBS also reduced. The SEM analysis showed that irradiation can improve the antioxygenic performance of SBS.  
        关键词：Styrene-Butadiene-Styrene (SBS);γ-ray;Irradiation effect   
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        发布时间：2023-03-30
      • LIU Qi,ZHU Zhiyong,YANG Xiaomin,CHEN Xiliang,SONG Yufeng
        Vol. 24, Issue 2, Pages: 97-101(2006)
        摘要：N-IPAAm monomers were grafted in/on Poly vinylidene fluoride (PVDF) micro-pore membrane by γ-irradiation. The grafting was characterized by Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements. Contact angle on the surface, electrical conductance and water penetration through the grafted membranes were tested. The results show that the N-isopropylacrylamide (N-IPAAm) monomers were successfully grafted on and inside the PVDF porous membrane. The hydrophilicity of the grafted membrane was improved and the membrane exhibits clearly temperature-sensitive permeability to water as expected, i.e., the permeability of water changes dramatically as the temperature goes above the lower critical solution temperature (LCST) of N-IPAAm.  
        关键词：Poly vinylidene fluoride (PVDF);Radiation grafting;Temperature sensitivity;N-isopropylacrylamide   
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        发布时间：2023-03-30
      • LIU Bing,ZHANG Hong,LI Wenjian,GAO Qingxiang,MIN Fengling,Xie Yi,HAO Jifang,DUAN Xin,ZHOU Qingming,ZHOU Guangming
        Vol. 24, Issue 2, Pages: 102-106(2006)
        摘要：The work is to investigate effects of AdCMV-p53 gene transfer induced by 60Co γ-rays on cell cycles of human colorectal adenocarcinoma cells. HT-29 cells exposed to 0.5, 1.0 and 2.0Gy were infected with AdCMV-GFP, a replication deficient recombinant adenoviral vector containing a CMV promoter and green fluorescent protein, or AdCMV-p53, a replication deficient recombinant adenoviral vector containing a CMV promoter and carrying human wild-type p53 gene. Survival rate of the cells was determined by clonogenic assay. Cell cycle and cell apoptosis were determined by flow cytometry. The results showed that, 0.5—1.0Gy irradiation significantly enhanced the inhibition of AdCMV-p53 infection on HT-29. Compared with the control, 1day after the infection, the cells in G0/G1 phase decreased by 5%—15%, the cells in S phase increased by 2%—19%. The 0.5 and 1.0Gy irradiation made the cells in the in G2/M phase increase by 12%, infected with 80 MOI AdCMV-p5. Three days later, the proportion of cells in G2/M phase in groups of 0.5 and 1.0Gy irradiation + 40 MOI AdCMV-p53 infection increased by 10%—13%. There was a relation between cell apoptosis and irradiation dose, or AdCMV-p53 dose. Therefore, the irradiation-induction could quicken the progression from G0/G1 phase to S phase, and promote S and G2/M phase arrest.  
        关键词：p53;Irradiation;Adenovirus vector;Colorectal adenocarcinoma;Cell cycle   
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        发布时间：2023-03-30
      • ZHANG Junxiang,KONG Zhaolu,SHEN Zhifen,TONG Shungao,JIN Yizun
        Vol. 24, Issue 2, Pages: 107-110(2006)
        摘要：The study was to evaluate radiosensitivity of a monoclonal human lung adenocarcinoma cell line SPC−A−1/CDDP−4 with MDR phenotype induced by cisplatin (CDDP) compared with its parental cell SPC−A−1 in vitro. The glutathione (GSH) content and the radiosensitivity of SPC−A−1/CDDP−4 and SPC−A−1 cells were investigated in aerobic and under hypoxia, respectively. The radiosensitization effect of buthionine sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, to SPC−A−1/CDDP−4 and SPC−A−1 cells was observed. The results indicated that the monoclonal human lung adenocarcinoma cell line SPC−A−1/CDDP−4 showed, to some extent, a cross−resistance to 137Cs γ−ray, in addition to its resistance to anticancer drugs (CDDP, ADM, MTX and VCR). The GSH content of SPC−A−1/CDDP−4 cells was higher than that of SPC−A−1 cells both in aerobic and under hypoxia which might account for it. BSO had radiosensitization effect to SPC−A−1/CDDP−4 and SPC−A−1 cells both in aerobic and under hypoxia, but it was stronger under hypoxia than in aerobic and it was stronger to SPC−A −1/ CDDP−4 cells than to SPC−A−1 cells.  
        关键词：Radiosensitivity;Multidrug resistance(MDR);Glutathione (GSH);Buthionine sulfoximine (BSO);Hypoxia   
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        发布时间：2023-03-30
      • XU Lixin,AI Huisheng,JIANG Benrong,YAO Bo,YU Changlin,GUO Mei,HUANG Yajing,SUN Qiyun
        Vol. 24, Issue 2, Pages: 111-114(2006)
        摘要：The work is to observe changes of the GADD45 (Growth arrest and DNA damage gene 45, GADD45) gene mRNA expression after X-ray irradiation and to study the relationship between the GADD45 expression and irradiation dose. Peripheral blood was irradiated to 0—5Gy by X-rays. MNCs (Mononuclear cell) were separated and cultivated. RT-PCR (Reverse transcriptase-Polymerase chain reaction) was used to measure relative expression of the GADD45 at different time points and relationship between the dose and expression was analyzed. After irradiation, the GADD45 gene expression increased in a dose-dependent form. Its peak expression was at 4h after irradiation, and began to decrease gradually from 4 to 24h. At time point of 24h, the GADD45 gene mRNA expression did not resume the original level before irradiation.  
        关键词：Growth arrest;DNA damage gene 45 (GADD45);Biodosimetry;Gene expression;Reverse transcriptase-polymerase chain reaction (RT-PCR)   
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        发布时间：2023-03-30
      • FENG Shuang,CAO Jianping,ZHU Wei,SONG Jianyuan,LI Chong,SHENG Fangjun,FAN Saijun,F. Eckardt-Schupp
        Vol. 24, Issue 2, Pages: 115-119(2006)
        摘要：In order to investigate mechanisms of ATM (Ataxia telangiectasia mutated) genes mediating phosphorylation of BRCA1(breast cancer gene 1) and its downstream gene RAD51 (DNA damage repair protein 51) in signaling pathway of DNA injury repair, we applied immunocoprecipitate and Western blot to observe changes in the expressions of BRCA1 and RAD51 proteins in AT cells, ATM+-AT cells (AT cells transfected with ATM genes) and GM cells (originated from human skin fibroblast, GM 0639) and used as control, after 5, 10 and 20Gy 60Co γ-ray irradiation at dose rate of 1.0Gy/min. The irradiated AT cells were analyzed to study interactive action between ATM and BRCA1 protein, BRCA1 and RAD51 protein, and the effect of PI3K inhibitor on ATM phosphorylating, its downstream gene, by immunocoprecipitate and Western blot. No expression bands of BRCA1 were found in ATM+-AT and GM cells of the control. After the irradiation, the BRCA1 and RAD51 were both expressed in GM and ATM cells. The PI3K inhibitor Wortmannin could inhibit the expression of BRCA1 in the AT, ATM+-AT and GM cells. The BRCA1 and RAD proteins were both expressed in ATM+-AT cells and GM cells. Therefore, after the irradiation the phosphorylation of BRCA1 mediated by ATM could further interact with RAD51. This is a cascade in signaling pathway for DNA damage repair and genome stabilization.  
        关键词：Ataxia telangiectasia mutated;Breast cancer gene 1;DNA damage repair protein 51;Phosphorylation   
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        发布时间：2023-03-30
      • ZHOU Xiaoguang,ZENG Guiying,REN Dongqing,FANG Henghu,SU Xiaoming,HUANG Xiaofeng
        Vol. 24, Issue 2, Pages: 120-124(2006)
        摘要：The work is to observe effects of PEMW (pulse electromagnetic wave) exposure on function and morphology of thyroid gland of rats. At different time points (24, 48, 96 and 192h) after exposure to PEMW (E=115kV m-1, 12000 pulses), radioimmunoassay was performed to observe the levels of thyroid-stimulating hormone (TSH), thyroxine (T4) and triiodo- thyronine (T3) in sera of the male Sparague-Dawley rats. Optic microscopy and transmission electron microscopy (TEM) were used to observe structural changes of the thyroid gland at the time points. The T3、T4 and TSH in sera increased significantly, reaching a peak at 24h and decreasing gradually then. Although no obvious changes in the thyroid gland were observed under the optic microscope, some ultrastructral changes in the thyroid gland were found under the TEM. The ultrastructures were obviously changed at 12h and aggravated until 48h. In the experimented rats, dilatated endoplasmic reticulum gathered with lots of protein excretion, lipid droplet and heterochromatin gathered under the nucleus membranes were observed in follicular epithelial cells. These changes were palliated at 96h but not recovered. PEMW can affect levels of hormones in sera and the hazard ultrastructual changes of thyroid gland. Endoplasmic reticulum is the main injured organelle.  
        关键词：Pulse electromagnetic wave(PEMW);Thyroid gland;Rat;Hormone;Morphous   
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        发布时间：2023-03-30
      • ZHANG Ning,YU Long,YANG Lifeng
        Vol. 24, Issue 2, Pages: 125-128(2006)
        摘要：Mutagenic effects of the transaminase producing bacterium Escherichia coli U12-3-19 by low energy metal ion (Ti2+ ) implantation were investigated. And the different mutagenic effects of E.coli irradiated with UV and low-energy ions were compared. The results showed that the E.coli after the ion implantation could achieve higher rate of mutation and wide mutational spectrum. A high yield L-phe strain has been bred from this. In the shaking flask, the L-phe productivity of strain U12-25-116-J75 increased by 22.67% than of the comparison strain with the PPA concentration of 20g/L.  
        关键词：Metal ion implantation;Mutation;Breed;L-phenylalanine   
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        发布时间：2023-03-30
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