最新刊期
      期 5 ， 2004
      • WANG Jianlong
        Vol. 22, Issue 5, Pages: 257-260(2004)
        摘要：Deinococcus radiodurans is a radiation−resistant bacterium, possessing remarkable resistance to a range of damage caused by ionizing radiations, desiccation, ultra−violet ray and oxidizing agents. Its potential applications include remediation of radioactive wastes−contaminated environments. Radiation−sensitive organisms cannot be used in the environment contaminated by both radioactive wastes and organic pollutants. Physicochemical cleanup technologies that could be used are expensive. The use of microorganisms to stabilize or detoxify these environments is a viable alternative. A bioremediation strategy based on the radiation−resistant bacterium Deinococcus radiodurans is being developed for the decontamination of sources where radiation levels are high. The genetic engineering could be overcome the physical, chemical, and physiologic constraints imposed on microorganism by radioactive wastes. Application of engineered D. radiodurans for the treatment of environments where radiation is the principle factor limiting microbial survival and function appears to be a potential and effective approach.  
        关键词：Deinococcus radiodurans;Engineered bacterium;radioactive contamination;complex contamination;Bioremediation;environmental biotechnology   
        2
        |
        0
        |
        5
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825581 false
        发布时间：2023-03-30
      • QIN Haifeng,BAO Huaying,JIA Haishun,LIU Yuanxia
        Vol. 22, Issue 5, Pages: 261-265(2004)
        摘要：The paper presents a review of polychlorinated biphenyls(PCBs) radiolysis in polar and nonpolar solvents. The solvated electron capture is the main reaction whether by 60Co−γ irradiation or electron beam as the radiation sources. The reactions follow the first or pseudo−first−order kinetics. The products are biphenyls and chloride.  
        关键词：polychlorinated biphenyls(PCBs);radiolysis   
        2
        |
        0
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825571 false
        发布时间：2023-03-30
      • ZHUANG Yinfeng,YANG Hua,WANG Guowei,ZHU Zhongqi,REN Fangfang,SONG Weiqiang,ZHAO Huidong
        Vol. 22, Issue 5, Pages: 266-270(2004)
        摘要：Hydrogels of poly N−isopropylacrylamide (PNIPA), poly (N−isopropylacrylamide−co−2−hydroxyethyl methacrylate) (P (NIPA−co−HEMA)) and PNIPA/P(HEMA) IPN (Interpenetrating Polymer Network) were prepared by radiation polymerization. Dependence of their swelling behavior on temperature was studied. Effects of absorbed dose and dose rate on polymerization, feed monomer concentration and ratio, and polymerization medium on phase transition temperature, swelling ratio, and swelling and deswelling kinetics of these hydrogels were disscused. Papain (PAP) was provided a model drug. An investigation of controlled drug release of the hydrogels was conducted. According to the experimental results, the hydrogels with optimum performances were produced at absorbed dose rate of 1kGy/h, total dose of 30—40kGy, 10% total monomer concentration, and in polymerization medium of n−butyl alcohol. These copolymer and IPN hydrogels were promising materials for developing controlled drug release system.  
        关键词：Radiation polymerization;N−Isopropylacrylamide;2−Hydroxyethyl Methacrylate;Hydrogels;Drug Release System   
        2
        |
        0
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825588 false
        发布时间：2023-03-30
      • LIU Zhaomin,XIAO Hui,FU Qun,ZU Jianhua
        Vol. 22, Issue 5, Pages: 271-275(2004)
        摘要：HDPE preirradiated under nitrogen protection was grafted with NIPA/AAc. The grafted hydrogel is temperature and pH sensitive. FTIR, DSC, SEM were used to study the composition, properties and surface morphology of the hydrogel. Results showing that LCST characteristics was different under different pH environment. Under acid condition, hydrogel volume increased with increasing temperature, indicating the hydrogel being heat expansive and temperature sensitive. Under neutral or alkaline condition, hydrogel volume contracted rapidly near phase transition with increasing temperature, indicating the hydrogel being heat shrinking and temperature sensitive.  
        关键词：Preirradiation grafting;Environmental sensitiveness;Hydrogel   
        2
        |
        0
        |
        4
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825585 false
        发布时间：2023-03-30
      • DENG Qiong,ZENG Qingxuan,FENG Changgen,ZHOU Shaoji
        Vol. 22, Issue 5, Pages: 276-280(2004)
        摘要：Some influencial factors of radiation induced graft of styrene-divinylbenzene onto polypropylene fibers have been studied by 60Co γ-rays. The results show that the self-polymerization will be less and the intake yield will be higher with monomer concentrations of 20%—25%, and the absorbed dose is higher than 15kGy. When the polypropylene fiber soaked in the graft solution for over 7h before the reaction, the influence of diffusion on the reaction can be avoided, with increased intake yield. Moreover, if the swelling is the dominant effect and the definite after-reaction time is kept, the intake yield improves. The best process of radiation induced grafting reaction was obtained by the study. The intake yield of products is 200%—280%, with a good mechanical property. It provides the eligible intermediate product for the large-scale production of ion exchange fiber.  
        关键词：Polypropylene fiber;Styrene-divinylbenzene;Radiation induced graft;Intake yield   
        2
        |
        0
        |
        6
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825583 false
        发布时间：2023-03-30
      • LI Daishuang,PENG Jing,ZHUANG Dechuan,ZHANG Xiaohong,QIAO Jinliang,WEI Genshuan
        Vol. 22, Issue 5, Pages: 281-284(2004)
        摘要：Powdered natural rubber can be prepared by using gamma-rays vulcanization and special drying method from natural rubber latex (NRL). This kind of powdered natural rubber would be expected to toughen plastics as an impact modifier and the property of natural rubber depends on its crosslinking degree. Therefore, it is necessary to study the crosslinking behavior of NRL under gamma irradiation. In the paper, the NRL was vulcanized with i-octyl acrylate (OA) as a crosslinking sensitizer under gamma irradiation. The influences of absorbed dose, dose rate and crosslinking concentration were discussed. The radiation vulcanization of NRL depends significantly on absorbed dose and crosslinking sensitizer content. The gel fraction of NR increased with absorbed dose and OA content, and it increased slightly above 10kGy. With increasing dose rate, the gel fraction decreased slightly. The highest gel fraction (about 90%) reached at dose of 25kGy with 5% OA. In the system, the radiation crosslinking behavior of NRL with OA as a crosslinking sensitizer could be described well with Charlesby-Pinner equation and G(x) was calculated to be about 3.8.  
        关键词：Natural rubber latex;Radiation vulcanization;i-octyl acrylate (OA)   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825667 false
        发布时间：2023-03-30
      • CHENG Qian,ZHANG Xiaolan,BAO Borong,WU Minghong,YE Guoan,ZHANG Xianye
        Vol. 22, Issue 5, Pages: 285-288(2004)
        摘要：The effect of γ-radiation on extraction behavior of U(Ⅵ) with TiAP and the extraction performance of U(VI) by acid and base washing were investigated. It was found that TiAP has better radiation stability compared with TBP. When absorbed dose reached 50kGy, the distribution ratio of U(VI) ascended remarkably. The effect of the addition of diluent was discussed, the experimental results show that kerosene is the best among irradiated diluents for U(VI) extraction. The study also suggests that radiation effect may be eliminated by back-extraction with 10% sodium carbonate.  
        关键词：γ-irradiation;Tri-isoamyl phosphate (TiAP);Solvent extraction;U(Ⅵ)   
        2
        |
        0
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825672 false
        发布时间：2023-03-30
      • GONG Bin,ZHANG Yewen,ZHENG Feihu,CHEN Lingyan,XU Jiaqiang,WANG Chuanshan
        Vol. 22, Issue 5, Pages: 289-292(2004)
        摘要：To control and measure depth profiles of charge deposition in the sample is of significance for researches of space charge break−down in high−voltage cable insulation and destruction of spacecraft by high−energy radiations. In this paper, Monte−Carlo simulation is used to get depth profiles of charge deposition in PMMA sample, Results of LIPP experimental measurement with EB irradiated PMMA ion experiments agree with the M-C simulation.  
        关键词：Electron beam irradiation;Space charge distribution;Monte−Carlo simulation   
        2
        |
        0
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825680 false
        发布时间：2023-03-30
      • SUN Hanwen,YU Jiahui,ZHANG Chunfu,XIE Leidong,HOU Zhengchi,XU Dongmei,YAO Side
        Vol. 22, Issue 5, Pages: 293-296(2004)
        摘要：Fe3O4 magnetic nanoparticles were modified with poly (N−isopropylacrylamide) under UV irradiation. It has been found that the diameter with narrow distribution of the modified Fe3O4 nanoparticles measured by PCS in aqueous solution can be controlled easily by changing concentration of monomer NIPAM and cross−linker MBA, temperature and time. It has been also shown that the modified Fe3O4 nanoparticles are featured by lower critical solution temperature (LCST) while the temperature varies from 25℃ to 39℃. This may suggest promising application of the nanopartucles in medicine.  
        关键词：Radiation;Poly (N−isopropylacrylamide);Magnetite;Magnetic nanoparticles   
        2
        |
        0
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825705 false
        发布时间：2023-03-30
      • LIU Yongbiao,LIU Ying,ZHAO Jie,HAO Xingzhi,WANG Xu,YAO Side
        Vol. 22, Issue 5, Pages: 297-302(2004)
        摘要：In order to investigate protection effects of SOD on the oxidized damage of normal tissues induced in chemotherapeutic drug and irradiated tumor−bearing mice, the contents of ROS and MDA, the activation of GSH−Px and CAT in liver, kidney, spleen and bone marrow have been determined. The effect of SOD on the ultra−structure of liver cell has been evaluated. It has been found that chemotherapeutic drug and irradiation can increase the contents of ROS and MDA and decrease activation of GSH−Px and CAT. And SOD can decrease contents of ROS and MDA and increase the activation of GSH−Px and CAT slightly for liver, spleen, marrow, but for kidney there is no significant change while SOD can reduce the damage of ultra−structure of liver. It can be inferred that SOD have some protection effects on the normal tissue of tumor−bearing mice via scavenging free radicals and activate anti−oxidative enzymes after TBI and drugs injection.  
        关键词：Superoxide dismutase;Ionizing radiation;Antitumor drugs;Tumor−bearing mice;Reactive oxygen species;Malondialdehyde;Glutathione peroxidaes;Catalase   
        2
        |
        0
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825772 false
        发布时间：2023-03-30
      • WANG Jufang,LI Wenjian,ZHOU Guangming,ZHAO Jing,DANG Bingrong,MAO Limin,FENG Yan
        Vol. 22, Issue 5, Pages: 303-306(2004)
        摘要：Bystander effects on unirradiated V79 cells were observed by irradiated conditioned medium (ICM) method and co−cultured with carbon−ion−irradiated V79 cells. The results showed that the colony formation efficiency of unirradiated cells is obviously decreased by ICM. After co−culture with carbon−ion−irradiated cells for some time, the colony formation efficiency of co−cultured cells was lower than expected results assuming no bystander effects. The micronucleus frequency and hprt gene mutation rate was almost the same as expected results. Cytotoxic factor(s), which was effective for cell growth but not for micronucleus and mutation on unirradiated cells, might be released by irradiated cells.  
        关键词：Bystander effects;Cells;Carbon−ion−irradiation;Colony formation efficiency;Micronucleus frequency;Mutation rate   
        2
        |
        0
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825754 false
        发布时间：2023-03-30
      • LU Zhaohong,ZHAO Jingyong,ZHU Mingqing,SHI Xijin,WANG Chunlei
        Vol. 22, Issue 5, Pages: 307-310(2004)
        摘要：The work is to study the mechanism of toxic effects on reproductive system and apoptosis of Chinese hamster ovary (CHO) cells induced by X-rays. CHO cell was exposed to X-rays 2 to 20Gy, Apoptosis and morphological changes of the cells were observed by fluorescent microscopy and flow cytometry analyzer with double staining with Annexin V/ PI. The apoptosis could be observed at 24, 48 and 72h after the exposure, but it was more obvious 48 and 72 h after the exposure. Rate of the apoptosis increased along with radiation dose were elevated. Some morphologyical changes, such as irregular agglomerate of chromatins, pycnosis and periphery distribution of nuclei, crescent-moon-like cell, small apoptosis body, were observed. Radiation results DNA damage in the CHO cells, and the demage cannot be repaired, hence the induced cell apoptosis.  
        关键词：Ionizing radiation;CHO cells;Apoptosis   
        2
        |
        0
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825735 false
        发布时间：2023-03-30
      • FENG Jiangbin,LU Xue,CHEN Deqing,CHEN Xiaosui,LIU Qingjie
        Vol. 22, Issue 5, Pages: 311-314(2004)
        摘要：This study is try to explore if the polymerase chain reaction (PCR) could be used to analyze the mitochondrial DNA 4977bp deletion (common deletion) induced by ionizing radiation. Peripheral blood samples were exposed to 2Gy 60Co γ-rays in vitro, and genomic DNA, including mitochondrial DNA, was extracted. A PCR method was tried to analyze the common deletion, including seldom deleted 16S-ND1 gene. The common deletions before and after the 2Gy exposure were analyzed with the PCR method. The results showed that the common deletion PCR products were detected after exposure to 2Gy in each peripheral blood sample. The purified PCR products were sequenced and carried out BLAST on standard human mitochondrial genome sequence database. The result showed that the common deletion flanked between 8470bp and 13446bp. Before exposed to 60Co γ-rays, no common deletion were not detected in the samples.These observations suggest that the PCR method, established in this study, could be used to detect the common deletion induced by ionizing radiation on peripheral lymphocytes samples.  
        关键词：60Co γ-rays;Mitochondrial DNA common deletion;PCR amplification   
        2
        |
        0
        |
        4
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825751 false
        发布时间：2023-03-30
      • ZHANG Liyuan,JIANG Jiagui,NING Ping,CHEN Liesong,ZHU Yongjin
        Vol. 22, Issue 5, Pages: 315-317(2004)
        摘要：The work is to observe whether human blood samples irradiated in vitro to 10cGy by X-rays could be an incentive to normal blood samples and blood cells injured by high dose radiation (1000cGy). The irradiated blood samples were cultured with blood samples collected from the same person, which were irradiated to 1000cGy or without irradiation. The cpm of 3H-TdR incorporation in different groups was measured after 72-hour culturing. Experiment results suggested that the blood irradiated to 10cGy could stimulate the blood cells irradiated to 1000kGy to proliferate. There is something in the plasma resulting in the stimulating effect.  
        关键词：Low dose radiation;Blood in vitro;Hormesis   
        2
        |
        0
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825774 false
        发布时间：2023-03-30
      • GAO Deyu,LI Hong,LIU Yuguang,HOU Jing,ZHENG Hui,SU Jun,MA Hongfei
        Vol. 22, Issue 5, Pages: 318-320(2004)
        摘要：Graft co-polymerization of acrylic acid (AA) and the acrylamide onto polypropylene (PP) fibers using pre-irradiation of γ-rays was studied. Characterization by FTIR showed that monomers were grafted onto the PP fibers. Results of the experiments with the grafted PP fibers showed that the grafting ratio could be improved by increasing the monomer concentration and absorbed dose of the grafting system. At 70℃, the grafting reaction was finished in about 4 hours. The grafting ratio could be as high as 200% by properly selecting the reaction conditions. Moisture absorption property of the PP fibers was improved.  
        关键词：Radiation graft;Polypropylene fiber;Acrylic acid;Acrylamide   
        2
        |
        0
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 35825783 false
        发布时间：2023-03-30
      0