最新刊期
      期 4 ， 2003
      • ZHAO Hongwei,KONG Ling,WANG Wenfeng,LIU Yongbiao,JIANG Zhiqin,MA Yunsheng,YAO Side
        Vol. 21, Issue 4, Pages: 225-226(2003)
        摘要：Fast reaction kinetics of •OH with N-4-desmethylwyosine (dYt), a derivative of rare tricyclic nucleoside has been studied by pulse radiolysis. The possible initial transient radicals of •OH adducts of dYt were studied by AM1 (with geometry optimization) and B3LYP/6-31G** (calculation of total energy). The radical reaction mechanism and the possible structure of OH-adducts were discussed and predicted.  
        关键词：Rare tricyclic nucleoside derivative;Pulse radiolysis;Radical;Theoretical calculation   
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        发布时间：2023-03-30
      • Wang Jianlong
        Vol. 21, Issue 4, Pages: 227-231(2003)
        摘要：Metallothioneins (MT) are low−molecualr weight (about6—7ku) and cysteine−rich (30%) metal−binding proteins, and their synthesis can be induced by radiation exposure. Biological functions of MT include mainly micronutrient, storage, transportation and metabolism, resistance to ionizing radiations, scavenger of free radicals and metal detoxification. The paper gives a review on MT classification, MT genes structure, gene amplification and regulation, radiation induced synthesis of MT and the mechanisms, and protective effects of MT to ionizing radiations.  
        关键词：Metallothionein;UV radiation;ionizing radiation.   
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        发布时间：2023-03-30
      • DOU Daying,WU Tieyi,MIAO Jinling,ZHAO Hongwei,YAO Side
        Vol. 21, Issue 4, Pages: 232-236(2003)
        摘要：Diethylstilbestrol (DES) is one of the most active environment estrogens. In this paper pulse radiolysis was carried out to study dynamic characteristics of active transient species of DES. The double bond between the benzene rings was supposed to be one of sites attacked by hydroxyl radicals. DES was rather sensitive to high-energy electron beam and their radicals can be easily degraded easily. The works will be of help for us to study degrading mechanisms and biological effects of DES, and to explore environment-repairing ways against DES.  
        关键词：diethylstilbestrol;transient spectrum;Pulse radiolysis   
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        发布时间：2023-03-30
      • Yuan Chengling,Yao Jianming,Wang Ji,Yu Zengliang
        Vol. 21, Issue 4, Pages: 237-242(2003)
        摘要：Low energy ion implantation technology was used in mutation breeding on arachidonic acid (5, 8, 11, 14−eicosatetraenoic acid, AA) yielding starting strain, Mortierelle alpina N7. The results indicate that dispersion of descendants of the N7 strain implanted with 10keV N+ (3×1014 N+/cm2) was bigger than that in natural division strain. I49−N18, a high−yield AA-producing strain, was screened out by continuous mutagenicity. The biomass, lipid in biomass, AA in lipids of the high−yield strain were 26.3g/L, 33.8%(w/w), and 52.36%(w/w), respectively. The AA content in culture was 4.66g/L, which is 126.2% higher than the control, and its descendiblity was stable. It is concluded that I49−N18 is a promising strain for industrialization, and that ion implantation has remarkable mutagenic effect on microorganism.  
        关键词：Aachidonic acid;Frmentation;In implantation;Mtagenicity;Sreening   
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        发布时间：2023-03-30
      • Guo Jinhua,Wang Haobo,Xie Chuanxiao,Wu Lijun,Yu Zengliang
        Vol. 21, Issue 4, Pages: 243-246(2003)
        摘要：Soybean seeds of Fengdou-101 were implanted by N+ ions. Cotyledon samples (24h, 96h) were collected randomly during cotyledons to primary leaves seedlings stage for testing. The effects of N+ ion (E=25kev) implantation (0—10.4×1016N+/cm2) on the activities of peroxidase(POD), catalase(CAT) and superoxides dismutase(SOD), content of malondiadehyde(MDA) and leakage of electrolyte were investigated in soybean seedlings. The results show that the SOD and CAT were the highest with doses from 6.5×1016 to 7.8×1016N+/cm2. The POD activity kept relatively stable level when the dose was lower than 5.2×1016N+/cm2, whereas the POD activity increased gradually with increasing doses above the threshold of 5.2×1016N+/cm2. The N+ ion implantation of soybean seeds reduced the accumulation of MDA and electrolytic leakage of cotyledons, and the lowest MDA content and the electrolyte leakage was found at 6.5×1016N+/cm2. It indicates that N+ ion implantation may reduce lipid peroxidation and improve the ability of cold acclimation in soybean seedlings.  
        关键词：N+ ion implantation;Soybean seedling;Lipid peroxidation;Enzyme activity   
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        发布时间：2023-03-30
      • Jin Hui,Chen Qinglong
        Vol. 21, Issue 4, Pages: 247-250(2003)
        摘要：Dosimetry simulation of 60Co irradiators is very important for improving γ-ray efficiency and ensuring quality of the radiation processing. For this purposes, a computer code in Visual Basic has been developed. Dosimetry calculation, sources arrangement and parameter adjustments are independently programmed in the code, which is easy to operate and suitable for a source plaque of three−level source pencil arrangement. Applications at our irradiation center show that the computer simulation agreed well with experimental results of the dosimetry distributions.  
        关键词：60Co;Irradiation;Dose field;Theory calculation   
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        发布时间：2023-03-30
      • LU Tingli,LIANG Guozheng,YANG Jieying,KOU Kaichang
        Vol. 21, Issue 4, Pages: 251-255(2003)
        摘要：Polytetrafluoroethylene films were grafted with styrene monomer by simultaneous radiation grafting. Effects of the grafting conditions, such as type of diluents, irradiation dose, dose rate and monomer concentration, were investigated. Results show that dose rate and monomer concentration were major factors of the radiation grafting. Dependence of the graft rate on dose rate and monomer concentration was 0.4 and 1.2, respectively.  
        关键词：Radiation−grafting;Styrene;Polytetrafluoroethylene film   
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        发布时间：2023-03-30
      • ZOU Yue,SUN Mingzhu,ZHOU Xiangyan
        Vol. 21, Issue 4, Pages: 260-263(2003)
        摘要：To investigate the changes in telomerase expression and its activity in A549 and L02 cells and their association with apoptosis after exposure of the cells to radiation, the hTERT expression and apoptosis occurrence in the cells by in situ telomerase−apoptosis double staining and the telomerase activity by TRAP were assayed. It is found that from 24—72h after exposure to 1—5 Gy γ−rays, the two cell lines showed a stronger hTERT expression, and the numbers of positive cells in telomerase−apoptosis double staining increased in a dose−dependent manner. Meanwhile telomerase activity in the cells of the two lines was upregulated dose−dependently during the development of apoptosis. The results suggested that the telomerase suppression might not be involved in the radiation−induced cell apoptosis and that telomerase may be related to chromosomal repair.  
        关键词：In situ telomerase−apoptosis double staining;Radiation;Human tumor cell line;Human normal cell line   
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        发布时间：2023-03-30
      • QIU Limei,LI Wenjian,FENG Yan,ZHOU Libin,ZHANG Gaohua,GAO Qingxiang,PANG Xinyue
        Vol. 21, Issue 4, Pages: 264-267(2003)
        摘要：In this paper, the time course of DNA damage in the human hepatoma cell line SMMC−7721 irradiated with 80 MeV/μ20Ne10+ was investigated. Irradiation was performed at the Heavy Ion Research Facility in Lanzhou (HIRFL), and the single cell gel electrophoresis (SCGE) was used to detect the DNA damage. Results showed that the "comet" tail length for the immediate irradiation-caused DNA damage had a positively linear correlation with the irradiation dose in the dose range of 0—8 Gy and the severer secondary damage was observed by 24h after irradiation.The results suggested that the heavy ion 80 MeV/μ20Ne10+, as a high LET radiation, had stronger effect than low LET radiations on cells, although the response curves for them were all positively linear.  
        关键词：Heavy ion;SMMC-7721 cells;SCGE;DNA damage;Time course   
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        发布时间：2023-03-30
      • Wu Congmei,Li Xiuyi,Tian mei,Liu Shuzheng
        Vol. 21, Issue 4, Pages: 268-271(2003)
        摘要：Mouse IFNγ cDNA was ligated to downstream of Egr−1 promoter to construct Egr−IFNγ plasmid. The recombined plasmids were transfected into B16 cells with lipsome, then the expression of IFNγ after different doses of X−ray irradiation and the time course of expression were detected by ELISA. The results showed that the expression levels in experimental groups were higher than that in the control group obviously (p<0.01); 6h after 2Gy X−ray irradiation, the expression of IFNγ was highest (p<0.01); The B16 cells transfected were given 2Gy X−ray irradiation every 24h, the expression level was highest after first irradiation (p<0.01)and then decrease gradually. The results indicated that ionizing irradiation can activate the Egr−IFNγ recombined plasmid and regulate the expression of IFNγ gene in B16 cells. The observation may be of potential significance in tumor therapy.  
        关键词：Egr−1 promoter;X−ray irradiation;IFNγ expression;ELISA   
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        发布时间：2023-03-30
      • LIU Hongyan,CONG Yuwen,SHAN Yajun,WANG Jinhui,YUAN Xiaoling,ZHAO Zhenhu,CHEN Jiapei
        Vol. 21, Issue 4, Pages: 272-275(2003)
        摘要：Microarrays except for cDNA expression arrays was used to profile changes in gene expression of bone marrow cell after exposed BALB/c to ionizing radiation (IR). The RNA from bone marrow cells was subjected to cDNA analysis on a microarray of 8079 known genes and ESTs.Data analysis showed that 660 genes changed at least 2-fold.among the 660 genes, 354 genes showed up-regulation in the radiated BALB/c, whereas 306 genes were down-regulated. 222 of the 660 genes are function known or inferred genes, which fell into categories of signal transduction, immunity or defense response, nucleic acid correlated, apoptosis, cell cycle, transport, metabolism etc. It is suggested that a variety of regulatory pathways in hematopoietic cells were affected by irradiation.  
        关键词：microarray;ionizing radiation;gene expression   
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        发布时间：2023-03-30
      • SUN Cuifeng,LIU Fenju,CHEN Jian,KONG Xiangrong,NING Ping
        Vol. 21, Issue 4, Pages: 276-279(2003)
        摘要：The work is to study the effect of lexA gene of Deinococcus radiodurans expressed in Escherichia coli on its resistance to γ−rays and MMC. Recombinant plasmid pZA172 was constructed by cloning the lexA gene of Deinococcus radiodurans into the vector plasmid PUC 19 in the downstream of lacZ promoter. Transfected Escherichia coli strain JM109(pZA172) was obtained through transfection of JM109strain with pZA172 by electroporation. Expression of the lexA protein in the IPTG−INDUCED JM109 (Pza172) was checked by SDS−PAGE, and survival curve of the strain was measured using colony formation assay after treatment with different doses of radiation and different concentrations of MMC. After IPTG induction, the lexA protein was significantly expressed in the strain JM109 (pZA172), and the survival rate of the strain was higher than that of the control. The expression of Deinococcus radiodurans lexA gene in Escherichia coli resulted in the increase of sensitivity of the latter to γ−rays and MMC. Mechanism of the effect remains to be further investigated.  
        关键词：Deinococcus radiodurans;Radioresistance;lexA gene;Escherichia coli;MMC   
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        发布时间：2023-03-30
      • GAO Yanhong,GAO Jianjun,JIN Weifang,WANG Hongfu
        Vol. 21, Issue 4, Pages: 280-283(2003)
        摘要：To observe the effects of exposure of rat ovary to radiation or OVX on the expression of TGF−β1 and COLI in the rat bone. The mRNA levels of TGF−β1 and COLI in rat tibiae were measured with RT−PCR after the rat ovaries were irradiated by 50Gy of 137Cs γ−rays or OVX. For both the radiation group and the OVX group, the COLI mRNA level in the rat bone increased, whereas the TGF−β1 decreased. Irradiation of ovary and OVX affect the expression of COLI and TGF−β1 mrna in bone probably in a similar way which is related to estrogen decrease.  
        关键词：Radiation of rat ovary;COLI;TGF−β1   
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        发布时间：2023-03-30

        研究论文

      • Zhou Zewei,Hu Bi,Shen Yu,Wang Zheng,Zhang Heqing
        Vol. 21, Issue 4, Pages: 256-259(2003)
        摘要：In search for less toxic and more effective radio−sensitizer, the effects of CGEONA (carboxy−β− phenyl−vinyl−germanium sesquioxide sodium salt)on radio−sensitivity of tumor−bearing mice and normal mice were investigated. Radiosensitizing experiment was performed using T−739 mice. The tumor model was LA−795 pulmonary adenocarcinoma, and the effect was assessed using tumor regrowth delay. Radioprotection experiments were performed using Kunming mice. The 30−day survival rate and effects on hemopoietic system were observed. It was shown that the average sensitization enhancement ratio (SER) of CGEONA was 1.4 with 1/10 LD50 drug dosage. The radioprotection experiments showed no significant differece between treated mice and control mice for survival rate and hemopoietic system. Thus, CGEONA shows great potential as a new type of radiosensitizer with less toxicity and more effectiveness. It has no radiosensitizing effect on normal mice and is worthy of further studies.  
        关键词：Germanium sesquioxide;Radiosensitizer;Tumor regrowth delay;Sensitization enhancement ratio;Radio−protection   
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        发布时间：2023-03-30
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