最新刊期
      期 3 ， 2002
      • SUN Cuifeng,LIU Fenju,WANG Tao
        Vol. 20, Issue 3, Pages: 161-165(2002)
        摘要：The bacterium ultraviolet Deinococcus radiodurans is extremely resistant to ionizing radiation, ultraviolet,peroxide and many other agents that damage DNA. Studies show that this resistance is due to Deinococcus radiodurans's extremely proficient and accurate DNA repair process. Our knowledge of this process is rudimentary. There are three types of DNA repair in Deinococcus radiodurans: base excision repair, nucleotide excision repair and recombinational repair. There is argument on whether Deinococcus radiodurans possesses SOS repair. In addition, chromosomal DNA degradation contributes to the accuracy of DNA repair in Deinococcus radiodurans.  
        关键词：Deinococcus radiodurans;Radioresistance;Excision repair;Recombinational repair;DNA degradation   
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        发布时间：2023-04-07
      • CAI Xichen,HAN Zhenhui,YAO Side,LIN Nianyun
        Vol. 20, Issue 3, Pages: 166-170(2002)
        摘要：We established a two—step two—laser photolysis method, in which the first laser excited molecules to a lower triplet state and another sequential laser excited it resonantly to higher triplet states or make it ionization. The two—step two—laser method provides a novel way to study the electron transfer of excited molecules. The higher excited benzophenone and its radical cation were observed under the time—resolved absorption method when it was excited to lower triplet state by one laser and another one excited it to higher triplet states resonantly. The higher excited benzophenone molecules undergoing intermolecular hydrogen abstraction with iso—propylalcohol molecules was faster than the lower one. This two—step two—laser excitation method provides a new way to study selective excited biomolecules especially for DNA molecules.  
        关键词：Two—laser photolysis;Excited triplet states;Benzophenone   
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        发布时间：2023-04-07
      • PENG Jing,ZHANG Xiaohong,QIAO Jinliang,WEI Genshuan
        Vol. 20, Issue 3, Pages: 171-177(2002)
        摘要：The crosslinking behavior of carboxylated styrene — butadiene rubber latex(CSBRL) by using gamma radiation with 2—ethyl hexyl acrylate(2—EHA) as crosslinking sensitizer has been studied in detail. In addition,the variation of the particle size and distribution of latex, chemical structure and thermal property of CSBRL with absorbed dose have been discussed. Also the radiation vulcanization mechanism of CSBRL has been suggested. The experiments showed that,the dose rate has small effect on the cross —link behavior of CSBRL,and the swelling ratio decreased rapidly with the increase of absorbed dose. Increasing the dose,the average molecular weight per crosslinked units(Mc) decreased and crosslinking density increased. When the dose is below 25kGy,no significant changes in the particle size and distribution of latex were observed. The micro—FTIR analysis and DSC curves confirmed the existence of grafting reaction accompanying the crosslinking reaction during the gamma irradiation with 2—EHA as sensitizer.  
        关键词：γ rays irradiation;Carboxylated styrene—butadiene rubber latex;Crosslinking behavior;Chemical structure   
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        发布时间：2023-04-07
      • ZU Jianhua,QIU Shilong,YE Yin,YAO Side
        Vol. 20, Issue 3, Pages: 178-182(2002)
        摘要：Acrylic acid (AA) and sodium styrene sulfonate (SSS) were grafted onto high—density polyethylene film by preirradiation, and we prepared an ion exchange membrane including strong acid and weak acid groups. The effect of pH on grafting yield was studied. In simultaneous radiation method Gt and Gs decrease with pH either HDPE grafted AA and SSS or AA—g—HDPE membrane grafted SSS. In preirradiation method Gt and Gs respectively increase with pH, and the highest grafting yield was observed at pH=2.80 then Gt and Gs decrease with pH. Viscity of grafting system was changed due to adjusting of pH,so that diffuse rate of monomers into matrix was affected.  
        关键词：Radiation grafting;pH effect;Diffusion rate   
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        发布时间：2023-04-07
      • LU Yingdong,HE Yongke
        Vol. 20, Issue 3, Pages: 183-186(2002)
        摘要：By studying the γ radiolytic gas products of an amido podand——N,N,N', N'—tetrabutyl—3—oxa—pentanediamide (TBOPDA),hydrogen alkanes and alkenes,and by contrasting their yields with another extractor TBP,we found out that the yields of the gas products of the amido podand are lower than those of TBP. It is possible that the amido podand is more stable than TBP under radiation. And the mechanism of the formation of hydrogen has been discussed.  
        关键词：Amido podand;Radiation;Stability   
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        发布时间：2023-04-07
      • ZHAO Tao,CUI Fengmei,ZHAO Jingyong,LAO Qinhua,WANG Liuyi
        Vol. 20, Issue 3, Pages: 187-190(2002)
        摘要：Using BrdU labeling to detect the HPRT gene mutation frequencies(MFs)of a normal adult induced by γ rays of different doses and to analysis the relationship between the HPRT gene MFs and the radiation doses. Blood was drawn via the vein of a normal adult and was equally divided into five groups. The blood was exposed to γ rays with a dose range from 0.0Gy to 4.0Gy respectively. After having cultivated the whole blood, we got the HPRT gene MFs of the lymphocytes. With the increase of the doses,the MFs of the HPRT gene rose accordingly. The result also showed that there is a linear—square relationship between the doses of the γ ray and the MFs of the HPRT gene. According to the result, we may conclude that BrdU labeling method is a quick,simple and relatively sensitive method for detecting the HPRT gene mutations of somatic cells induced by external radiation exposure and HPRT gene mutation may be used as a radiobiological dosimeter.  
        关键词：BrdU labeling method;HPRT gene;Mutation frequencies;Dose—effect relationship   
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        发布时间：2023-04-07
      • REN Zhenyi,BAI Chunxue,HONG Qunyin,ZENG Zhaochong,JIN Yizun
        Vol. 20, Issue 3, Pages: 191-196(2002)
        摘要：In this paper the radiosensitization of docetaxel on Lewis lung cancer was investigated in vivo. C57BL mice bearing Lewis lung cancer were treated with 207mg/m2 docetaxel to determine the ability of the drug to induce mitotic arrest and apoptosis in tumor cells. The mice bearing Lewis lung cancer in the right hind leg were locally irradiated with single dose of 10Gy 137Cs γ rays using small animal irradiator. The results showed that the percentage of arrested cells increased rapidly with the time,achieving its peak of 31.9% 12h after docetaxel administration. Docetaxel also induced apoptosis within 48h. Treated by different doses of docetaxel 12 or 48h prior to irradiation,the tumors grew slowly,the growth inhibition rates of the tumors increased, and the relative growth rates decreased significantly. The q value in every radiosensitizing group ranged from 1.21 to 1.38. These results indicated that docetaxel exerted its radiosensitizing potential by the mechanism of arresting mitosis and inducing apoptosis. This study suggested that docetaxel had a high potential as a successful radio sensitizer in the clinic treatment of lung cancer.  
        关键词：Docetaxel;Radiosensitization;Lewis lung cancer   
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        发布时间：2023-04-07
      • LIU Yuwen,ZHANG Zhiqian,LI Fengmei,YU Jianyuan,CHEN Fengen
        Vol. 20, Issue 3, Pages: 197-203(2002)
        摘要：The object of this work is to investigate the effect of EB irradiation on carbon fiber surface. The laser Raman spectroscopy, X ray photoelectron spectroscopy (XPS),atomic force microscopy (AFM) and X ray diffraction were used to observe the surface changes including an enhancement in oxygen and nitrogen containing groups,smooth degree of carbon fiber surface and in size of graphite crystal layers. It showed that polar groups on carbon —fiber surface were influenced by the active species creacted in the media during EB irradiation. The self—quenching reaction or disengage reaction took place in activated groups. The group C=O was increased in the former reaction, on the other hand, the group C—O in the latter reaction. The crystal structure of the bulk carbon fiber was not effected by EB irradiation.  
        关键词：Electron beam;Carbon fiber;Surface structure;Radiation effect   
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        发布时间：2023-04-07
      • SUN Liang,LI Shijun
        Vol. 20, Issue 3, Pages: 204-208(2002)
        摘要：It is important for internal radiation dose of radiopharmaceuticals to calculate disintegration in source organs. On the base of briefly introducing the calculation model,this paper presents specific software BIKNC 1.0 for calculating disintegration more quickly and accurately. As the experimental calculation shows,BIKNC 1.0 is fit for practice.  
        关键词：Disintegration;BIKNC 1.0   
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        发布时间：2023-04-07
      • JIN Shunzi,HE Shumei,LIU Shuzheng
        Vol. 20, Issue 3, Pages: 209-212(2002)
        摘要：To observe the effects of low dose radiation (LDR) on the activity of the CuZn superoxide dismutase (CuZn SOD) in the peritoneal macrophages of mice, we used blot hybridization and MTT methods to detect the changes of this enzyme in the peritoneal macrophage of mice irradiated with 0.075Gy of X rays at both the mRNA level and the protein level (activity). The results showed that after irradiation with LDR the CuZn SOD mRNA expression in the macrophages increased, but the CuZn SOD activity had no noticeable change. However from 8 to 24h after irradiation with 2Gy,the CuZn SOD activity in the macrophages increased obviously.  
        关键词：Ionizing radiation;Mouse Peritoneal macrophage;CuZn SOD;mRNA   
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        发布时间：2023-04-07
      • LU Yingdong,HE Yongke,WU Jilan
        Vol. 20, Issue 3, Pages: 213-215(2002)
        摘要：An abnormal rate constant about 1.4×1013 L-1•mol•s-1 of excited energy transfer has been found in the γ radiolysis of C6H12—TOPO system by analyzing the main radiolysis products hydrogen,cyclohexene and bicyclohexyl  
        关键词：Cyclohexane (C6H12);Trioctyl phosphine oxide (TOPO);γ radiolysis;Energy transfer;Abnormal rate constant   
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        发布时间：2023-04-07
      • KONG Zhaolu,JIN Yizun,SHEN Zhifen
        Vol. 20, Issue 3, Pages: 216-219(2002)
        摘要：In this paper, the change of glutathione (GSH) content in the X ray irradiated human stomach cancer cell line SGC7901 which were pretreated with buthionine sulfoximine(BSO) were studied. The results showed that the GSH content in these cells decreased rapidly and the change was independent to the radiation dose. On the contrary, there was a trend for the un—pretreated control cells that the GSH level in the cancer cells rose alone with the increase of radiation dose.  
        关键词：glutathione;Irradiation;buthionine sulfoximine;γ glutamylcysteine synthetase   
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        发布时间：2023-04-07
      • ZHANG Junning,HONG Chengjiao,ZHU Shoupeng
        Vol. 20, Issue 3, Pages: 220-224(2002)
        摘要：DNA single — and double — strand breaks of peripheral blood lymphocytes in mice induced by γ rays irradiation were detected by neutral and alkaline comet assay. The results indicated that γ rays caused the increase of DNA migration length in the lymphocytes in a dose —dependent manner. It should be noted that comet assay can be applied not only to monitor DNA single and double strand breaks in vivo or in vitro,but also to serve as a new biological dosimeter.  
        关键词：Neutral comet assay;DNA double strand breaks;Alkaline comet assay;DNA single strand breaks;Lymphocytes;γ rays irradiation   
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        发布时间：2023-04-07
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