最新刊期
      期 6 ， 2008
      • ZHOU Liwei,CHEN Xiaoming,ZHANG Jianguo,LIU Fang
        Vol. 26, Issue 6, Pages: 321-325(2008)
        摘要：A DNA molecule is both the carrier of biological information and the main target of biological effects induced by ionizing radiation. Irradiation leads to many types of DNA damage by the direct and the indirect radiation effect. DNA double-strand breaks (DSB) induced by ionizing radiation represent the primary damage of all bio-effects. Currently, the detecting methods dealing with DSB include raman spectroscopy analysis, atomic force microscopy analysis, single cell gel electrophoresis, pulsed-field gel electrophoresis, γ H2AX analysis and premature chromosome condensation analysis, etc. And the statistical models of DNA DSB involve in the random fracture model, the moment method, the tsallis entropy model and the average molecular weight method. Both of them have been discussed in this paper. Finally, the research prospect of the DNA DSB radiation hotspot is presented.  
        关键词：DNA double-strand breaks;Double-strand breaks detect methods;Double-strand breaks statistical models;Double-strand breaks radiation hotspot   
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        发布时间：2023-03-30
      • PENG Chaorong,CHEN Hao,WANG Jingxia,WU Ling,CHEN Zhuping,DENG Huachuan
        Vol. 26, Issue 6, Pages: 326-330(2008)
        摘要：Poly (L-lactic acid) was irradiated by γ-rays. The effects of absorbed dose on viscosity average molecular weight, crystallization and thermal weight loss in irradiated condition under vacuum, nitrogen, air and oxygen were investigated, which were characterized by using ubbelohde viscometer, differential scamming calorimeter (DSC), polarized microscope and thermogravimetry analysis (TGA). Viscosity average molecular weight of PLLA decreases with increment of absorbed dose and viscosity average molecular weight of PLLA irradiated in vacuum is highest among the different irradiated condition at same absorbed dose. Both degree and rates of crystallization increase with increment of absorbed dose and TGA curves of PLLA irradiated under vacuum or nitrogen are shifted towards higher temperature compare with un-irradiated sample at the absorbed dose from 6~40kGy. The weight loss of PLLA irradiated under oxygen is lower than that under vacuum at absorbed dose of 6kGy.  
        关键词：Poly (L-lactic acid);γ-rays irradiation;Crystallization;Thermal stability   
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        发布时间：2023-03-30
      • FAN Zhipeng,LI Haihong,LIU Meihua,ZHENG Xiaowei,ZHANG Wanxi,DENG Pengyang,DONG Lisong
        Vol. 26, Issue 6, Pages: 331-334(2008)
        摘要：Ethylene-vinyl alcohol-g-acrylic acid (EVOH-g-AA) copolymer was prepared by melt esterification reaction. FTIR was used to characterize the graft product. Gel extraction results show that EVOH-g-AA becomes easier to be cross-linked by radiation at low absorbed doses, which is different with neat EVOH due to the introduction of vinyl double bond. From the study of irradiated effect of PLA/ EVOH-g-AA blends it has been found that PLA could enter the crosslinking network. So the EVOH-g-AA could be used as enhance radiation cross-linking agent.  
        关键词：Ethylene-vinyl alcohol copolymer;Acrylic acid;Graft;Radiation crosslinking   
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        发布时间：2023-03-30
      • LIU Zhenzhen,MAO Wenjun,ZHU Hong,ZHU Rongrong,SUN Xiaoyu,YAO Side,WANG Shilong
        Vol. 26, Issue 6, Pages: 335-342(2008)
        摘要：A mutation of wild strain Trichoderma Viride Tr-02 irradiated by laser was studied in this paper. A high xylanase-producing strain was obtained by two steps oriental screening finally. The results show that an optimization condition of the xylanase fermentation is as following: 0.5% corncob as the carbon source, 0.5% peptone as the nitrogen source, 0.1% Tween-80 as a enzyme-promoting agent, initial medium pH to 5.0, medium volume to 100mL, vaccinated two rings of spores, 28℃, 180 r/min, fermented 48h. The xylanase activity of the mutant reaches 281.21U/mL and is 31.83% higher than that of the original strain under the same conditions.  
        关键词：Laser;Trichoderma viride;Xylanase;Fermentation   
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        发布时间：2023-03-30
      • ZHAO Weiping,ZHANG Hong,WANG Yanling,LI Ning,LIU Bin,WU Zhenhua,XIE Yi,HAO Jifang,LIU Yang
        Vol. 26, Issue 6, Pages: 343-347(2008)
        摘要：In order to observe the effect of low dose 12C6+ irradiation on cell cycle and DNA damage in mouse thymus and spleen cells the mice were whole-body irradiated with 0, 10, 50, 75, 100 and 250mGy 12C6+ ion and executed six hours after. Flow cytometry was used to test the changes on thymus and spleen cell cycle and the frequencies of cells with tail moment and the tail lengths were determined by the single cell gel electrophoresis. The results show that the percentages of G0/G1 phase cells reduce and the percentages of S phase cells increase significantly in thymus compared with control (p<0.05), while the percentages of G0/G1 phase cells increase and the percentages of S phase cells decrease obviously in spleen of mice (p<0.01). Similarly, the length of the tails and the number of cells with tail rise as the absorbed dose increased, which has the obviously dose-effect dependent relationship. Low dose 12C6+ irradiation can effectively stimulate DNA synthesis in thymus and can be inhibited at G0/G1 in spleen of mice. At the same time, it can induce DNA damage along with the absorbed doses.  
        关键词：Low dose 12C6+ ions;Irradiation;Cell cycle;DNA damage   
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        发布时间：2023-03-30
      • SHI Lili,LIU Xiqin,ZHANG Xiaohong,ZHU Xixu,FENG Jundong,CHEN Da
        Vol. 26, Issue 6, Pages: 348-352(2008)
        摘要：In this paper the effects of sympathectomy on T lymphocytes of irradiated mice were investigated. The whole blood sample was collected from mice irradiated with 0.5Gy, 3Gy and 6Gy and injected with 6-OHDA respectively. The number of T lymphocytes, T lymphocyte subsets and their activated cells were detected by flow cytometry. Results show that the thymus index of irradiated mice with sympathectomy obviously decline. And the number of T, Th and Tc/Ts cells collected from irradiated mice decrease with the increment of absorbed doses. The number of Th, Tc/Ts cells becomes obviously larger though the number of T cells of sympathectomized group is smaller than that of the group without sympathectomy at the same absorbed doses. Compared with the control group, the number of CD3+ CD25+, activated Th and Tc/Ts cells increase with the increment of absorbed doses while the parameter of the sympathectomized sample are larger than that of control group. All these indicate that the sympathetic nerve has a positive function to the immune function of irradiated mice.  
        关键词：Sympathectomy;Irradiation;T lymphocyte LCL R811   
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        发布时间：2023-03-30
      • ZHU Wei,LIU Fenju,CAO Jianping,ZHU Caiying,FAN Saijun
        Vol. 26, Issue 6, Pages: 353-356(2008)
        摘要：In order to study the effect-dosage relationship between the PCC induced by Okadaic acid and the IR dosages, human peripheral blood in vitro was irradiated by X-rays at different doses (0、0.5、1.0、2.0、3.0、5.0Gy) cultivated for 48 hours and added with Okadaic acid two hours before the end of culture. Chromosome aberrations frequencies was analyzed and compared with that induced by the conventional chromosome assay and their dose-response curves were fitted. The results show that the mitotic index of the PCC induced by Okadaic acid is higher than that of the conventional chromosome assay. And the fragment rate of chromosome condensation induced by Okadaic acid has a favorable linearity relationship with external radiation doses.  
        关键词：Okadaic acid;Premature condensed chromosome (PCC);Ionization radiation;Biological dose   
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        发布时间：2023-03-30
      • LI Xinli,FAN Saijun
        Vol. 26, Issue 6, Pages: 357-362(2008)
        摘要：In order to study the effect of UHRF1 on growth and radiosensitivity of breast cancer MDA-MB-231 cells, The stable clones of MAD-MB-231 cells with UHRF1 gene overexpression were established by transfection of a full-length human UHRF1 cDNA which was cloned into a mammalian expression vector pcDNA3. And the effect of UHRF1 on growth of MDA-MB-231 cells was identified by population double time and colony formation assays. The change of radiosensitivity after γ-irradiation was determined by colony formation assay. It has been found that enhanced expression of UHRF1 does not affect cell growth and colony formation. However, in comparison with MAD-MB-231 parental cells and MAD-MB-231/pcDNA3 cells, MAD-MB-231/UHRF1 cells are less susceptibility to γ-irradiation. These results indicate, for the first time, that human UHRF1 may be an important mediator in radiotherapy of breast cancer, although further study is still needed.  
        关键词：Human UHRF1 gene;Breast cancer;Stable transfection;Cell growth;Radiation sensitivity   
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        发布时间：2023-03-30
      • DENG Yu,GAN Huilu,LI Jianyin
        Vol. 26, Issue 6, Pages: 363-366(2008)
        摘要：Effect of microwave radiation on whiteness and hardness of bleached wheat straw pulp were investigated. It has been found that microwave irradiation time, microwave irradiation power and sodium hypochlorite dosage are the main parameters to the whiteness and hardness of bleached wheat straw pulp. The experiment show that with the increment of microwave irradiation power, microwave irradiation time and concentration of sodium hypochlorite whiteness of pulp can increase but hardness decreases. In this paper the bleaching processing experiments by use of water bath and microwave radiation have been done and the results indicate that at the same whiteness of bleached pulp the microwave radiation can save much more bleaching time compared with that by water bath.  
        关键词：Microwave radiation;Bleaching;Wheat straw pulp;Potassium permanganate value   
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        发布时间：2023-03-30
      • LIU Yang,ZHANG Hong,ZHANG Luwei,ZHAO Weiping,WU Zhenhua
        Vol. 26, Issue 6, Pages: 367-370(2008)
        摘要：The present study was designed to evaluate the effect and mechanism of N-acetylcysteine (NAC) against from acute injury of mice exposed to 12C6+ ion beams. Pretreated with NAC (200mg/kg) Kun-Ming mice were exposed to whole-body irradiation of 4Gy and were killed at 2h after irradiation, and then their liver and lung tissues were quickly treated for further experiment. The Superoxide dismutase (SOD) activity, glutathione (GSH) content and malondialdehyde (MDA) level were measured by chemical method and DNA-single strand breaks were determined by single cell gel electrophoresis meanwhile the percentage of cell apoptosis were assayed by flow cytometry method. In comparison with the respective control, NAC pretreatment can significantly alleviate DNA-single strand breaks (p<0.001), cell apoptosis (p<0.001) and obviously enhance GSH content in the liver and lung tissues. Moreover, NAC can prominently inhibit the increment of MDA level (p<0.01) induced by 12C6+ ion beams and can augment SOD activity (p<0.01) in the lung.  
        关键词：N-acetylcysteine;12C6+ ions;Mice;Anti-radiation damage   
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        发布时间：2023-03-30
      • LI Yu,LI Zhiheng,V.Yu. Kravtsov,S.S. Aleksanin
        Vol. 26, Issue 6, Pages: 371-373(2008)
        摘要：In order to study "tailed nuclei" (TN) in peripheral blood smears from irradiated Chernobyl liquidators, human peripheral blood lymphocytes from irradiated Chernobyl liquidators as experiment group were selected to observe under microscope and record different TN pattern in routine Giemsa dyeing method with 500 cells. Result shows that TN percent in control group is 0 to 1.0% while the TN percent in the irradiated group is higher (most is 3.2%). The frequency of appearance of lymphocytes with TN in a group of Chernobyl liquidators is significantly higher than that in control groups (p<0.01). Abnormalities of the TN type in irradiated lymphocytes may be from breakdown of chromosome bridges formed in dicentrics. The TN could be considered as a possible marker involved in radiation damage of biological tissue.  
        关键词：Chernobyl nuclear accident;Radiation;Tailed nuclei (TN)   
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        发布时间：2023-03-30
      • CHEN Xueling,CHENG Wei,XIONG Guangquan,YE Lixiu,CHEN Yuxia,GUAN Jian,HE Jianjun
        Vol. 26, Issue 6, Pages: 374-376(2008)
        摘要：The effects of irradiation on sterilization and storage time for the freezing-dried Wuchang fish were studied. The results show that the number of the coliform group in freezing-dried Wuchang fish irradiated at 1kGy can be acceptable according to the national industrial standard and the number of bacteria decrease from 3100cfu/g to <10cfu/g after irradiation. With the optimal irradiation dose 1kGy the shelf life of Wuchang fish can be extended over one year.  
        关键词：Freezing-dried Wuchang fish;Irradiation;Killing bacteria   
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        发布时间：2023-03-30
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