最新刊期
      期 6 ， 2009
      • QIAN Liren,HUANG Yuecheng,CAI Jianming
        Vol. 27, Issue 6, Pages: 321-325(2009)
        摘要：Ionization radiation can generate free radicals in biological system, which could induce lipid peroxidation, biomacromolecule and biomembrane damage, lost of cell function, cell cycle disturbance, genetic mutation and so on. The scavenging free radicals can protect organism from radiation damage. Many radio-protective agents, such as amylase, hydroxyl-benzene derivatives, hormone, vitamin, have great abilities to protect organism from radiation via scavenging free radicals. In this paper, we mainly review the free radical scavenging effects of several kinds of radio-protective agents.  
        关键词：Free radical scavenger;Radio-protective effect;Antioxidant   
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        发布时间：2023-03-30
      • MIN Rui
        Vol. 27, Issue 6, Pages: 326-330(2009)
        摘要：Radiation chemistry acts as a bridge connecting radiation physics with radiation biology in spatial and temporal insight. The theory, model, and methodology coming from radiation chemistry play an important role in the research and development of radiation biology. The chemical changes induced by ionizing radiation are involved not only in early event of biological effects caused by ionizing radiation but in function radiation biology, such as DNA damage and repair, sensitive modification, metabolism and function of active oxygen and so on. Following the research development of radiation biology, systems radiation biology, accurate quality and quantity of radiation biology effects need more methods and perfect tools from radiation chemistry.  
        关键词：Radiation chemistry;Radiation biology;Biological effect induced by radiation   
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        发布时间：2023-03-30
      • ZHANG Xinhui,XIN Xiaoyan,ZENG Lihua,GUO Guozhen
        Vol. 27, Issue 6, Pages: 331-336(2009)
        摘要：In order to study the effect of drug resistance on the radiosensitivity of human ovarian cancer lines exposed to 60Co γ-rays at low absorbed doses, the human ovarian cancer cell line A2780 and its paclitaxel (PTX)-resistant subline A2780/Taxol were used as a model of the cells. MTT assay was used to determine the sensitivity of the cells to paclitaxel and radiation. Radioresistance of cells was calculated by colony formation test. The real time PCR was used to determine the variation in the expression of mRNA of MDR1 in the model cells before and after radiation. It has been found that the resistance index (RI) of A2780/Taxol cells is up to 43.96, while the relative survival rate of A2780 cells is more significant than that of 2780/Taxol cells with increment of radiation absorbed dose (p<0.05). The results indicate that the PTX-resistant cell line A2780/Taxol has significant radio-resistance. Drug and irradiation can induce over expression of MDR1, which may be one of the main reasons of crossed resistance to chemotherapy and radiotherapy in human ovarian cancer.  
        关键词：Ovarian cancer cell line A2780;Paclitaxel;Radioresistant;MDR1 gene   
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        发布时间：2023-03-30
      • QIN Pei,TANG Bin,FU Yuchuan,HE Xiaohai
        Vol. 27, Issue 6, Pages: 337-340(2009)
        摘要：The radiation protection in radiation processing with low energy electron beam is generally achieved by applying self-shielding. The self-shielding layers should shield bremsstrahlung photons effectively. The bremsstrahlung of low energy electrons striking on steel and polyethylene has been simulated with Monte Carlo system EGSnrcMP. The relations between the energy spectra, angular distributions of bremsstrahlung photons and target materials and depths are analyzed and discussed. The basic data can be used to optimize the self-shielding design.  
        关键词：Low energy electrons;Bremsstrahlung;EGSnrcMP;Self-shielding radiation protection   
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        发布时间：2023-03-30
      • LIU Feng,ZHAO Enshun,TANG Anbin
        Vol. 27, Issue 6, Pages: 341-344(2009)
        摘要：In this paper, the boron-modified binary primary amines benzaoxazine and the binary primary amines benzaoxazine was synthesized respectively. The resin was characterized by Fourier Transform Infrared Spectroscopy spectrum respectively. The laminates, which were pressed by two kinds of resin respectively, were irradiated by γ-rays and inspected the affection of radiation resistance after introducing of boron atom by comparing the performance of laminates after radiation. The performance of mechanics and electricity was investigated before and after radiation with two kinds of laminates. The result indicates that the radiation resistance of laminate was improved by introducing boron atom.  
        关键词：Boron-modified benzoxazine;Laminate;γ-irradiation   
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        发布时间：2023-03-30
      • ZHANG Yan,XIE Leidong,SHENG Kanglong
        Vol. 27, Issue 6, Pages: 345-349(2009)
        摘要：This work is aimed at improving compatibility of styrene-butadiene-styrene (SBS) copolymer / polyamide 6 (PA6) blends through radiation crosslinking of the blends by 60Co γ-rays, in which three-dimensional network structure is formed by the crosslinked SBS molecular chains. Micro-morphology, rheological properties, mechanical properties and water absorption of the PA6 / SBS blend with different ratios irradiated to 100 kGy were characterized by relevant instrumental techniques. The results show that performance of the SBS/PA6 blends could be improved by radiation modification of the SBS copolymer.  
        关键词：Styrene-butadiene-styrene copolymer;Polyamide 6;Blend;Radiation crosslinking;Compatibility   
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        发布时间：2023-03-30
      • PENG Chaorong,WANG Jingxia,CHEN Zhuping,LIU Siyang
        Vol. 27, Issue 6, Pages: 350-354(2009)
        摘要：Composites of polyvinyl chloride (PVC) filled with stabilizers was irradiated by 60Co γ-ray. The effect of different stabilizers on the radiation-induced discoloring of PVC was investigated and the structures of irradiated PVC were characterized by ultraviolet spectrum (UV) and Fourrier transfer infrared spectrum (FT-IR). It shows that the stabilizers including calcium stearate / zinc stearate, epoxidised oil, phosphite and photostabilizer can improve the property of resistance to radiation-induced discoloring of PVC, and phosphite can improve the property of resistance to radiation-induced oxidation of PVC. Among the stabilizers, formulations with calcium stearate/zinc stearate show high transparency and excellent property of resistance to radiation at same absorbed dose. Change rate of yellow index of formulation (calcium stearate: zinc stearate=2:1) has been determined to be 8.3% at the absorbed dose of 30 kGy. It has been found that the structures of PVC with numbers of conjugated double bond or α, β-unsaturated ketone are formed after irradiation by γ-rays.  
        关键词：Polyvinyl chloride;Stabilizer;Radiation;Discoloring   
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        发布时间：2023-03-30
      • ZHANG Lei,XU Shangcheng,ZHANG Guangbin,YU Zhengping
        Vol. 27, Issue 6, Pages: 355-359(2009)
        摘要：The present study is to examine the effect of microwave on acid sphingomyelinase (ASM) activity and expression, and to explore the role of ASM activation in neuronal cells apoptosis induced by microwave irradiation. Primary cultured hippocampal neurons were irradiated by 30 W/cm2 microwave for 10 min, and ASM activity assay was used to investigate ASM activity alteration. RT-PCR and western blot were used to detect ASM mRNA and protein expression respectively. Apoptosis was observed by Hoechst 33342 fluorescence staining. ASM specific inhibitor imipramine was applied to inhibit ASM activation. It has been found that apoptosis rate of primary cultured hippocampal neurons increased significantly after microwave irradiation. ASM was activated while ASM mRNA and protein expression were up-regulated in neurons after microwave irradiation. Pretreatment with imipramine could reverse neuronal apoptosis induced by microwave irradiation. Results show that microwave irradiation causes increment of ASM activation and expression and ASM activation is involved in microwave induced neuronal apoptosis.  
        关键词：Microwave irradiation;Primary cultured hippocampal neurons;Acid sphingomyelinase (ASM);Apoptosis   
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        发布时间：2023-03-30
      • GUO Ling,HE Yingjie,ZHENG Li,LÜ Chao,DING Zhenhua
        Vol. 27, Issue 6, Pages: 360-364(2009)
        摘要：In order to study the expression level of let-7a in HaCaT exposed to UVB real-time qPCR was used to detect the expression level of let-7a at 2 h, 4 h, 8 h, 12 h and 24 h after UVB irradiation. Online database PicTar can be used to predict the targets of let-7a and performed function categories with softerware Gostat. The results show that the expression level of let-7a at 12h is higher than that at other time points with more than 7 times. The target prediction and Gostat analysis indicate that casp3、bcl2l2、map3k1 and cdk5 may be UVB-induced target genes of cell cycle regulation. These results suggest that let-7a may play a key role in the mechanism of UVB-induced injury.  
        关键词：Let-7a;HaCaT;Ultraviolet B   
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        发布时间：2023-03-30
      • LIU Yang,CAO Jianping,FAN Saijun,ZHU Wei,PENG Xiaomei,TANG Yan,CHEN Xialin,WU Jinchang,ZHOU Jundong
        Vol. 27, Issue 6, Pages: 365-368(2009)
        摘要：In order to analyze the change of micronucleus in the p53 mutant human breast cancer cells MDA-MB-435 caused by artemisinin additive, MTT method was used to check the effect of different concentration and treatment time of artemisinin to cytotoxicity. Cytokinesis block micronucleus method (CB method) was used to determine the micronucleus frequency (MNF) and the micronucleus cell frequency (MNCF) of cells treated by artemisinin additive and with different doses of 60Co γ-rays. The experiment results show that artemisinin is of little toxicity to MDA-MB-435. When drug concentration is 200μmol/L and treatment time is 24 h, the dose-response curves of MNF and MNCF of irradiated cells combined with treatment of or not artemisinin additive confirm that MNF and MNCF of cells treated by artemisinin are both significantly higher than that treated by radiation alone. It can be deduced that artemisinin may have some sensitive action on radiation therapy.  
        关键词：Artemisinin;Radio sensitivity;Micronucleus   
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        发布时间：2023-03-30
      • SUN Meiling,YU Jingping,LIU Fenju,LIU Haiyan,YANG Chen
        Vol. 27, Issue 6, Pages: 369-373(2009)
        摘要：In order to investigate the inhibition effect of X-rays combined with thalidomide on glioma U251 cells, the cell scratch assay was used to detect the inhibition of thalidomide on U251 cells. And H3-TdR incorporation assay and colony formation were used to investigate the enhancement effect of thalidomide on the sensitivity of U251 cells to X-rays. It has been found that thalidomide has synergistic effect on therapy of glioma U251 cells if it is combined with X-rays irradiation as it can inhibit cells infiltration, DNA synthesis and colony formation. When the survival rate of glioma U251 cells is 50%, the radio-sensitization factors of 60 μg/mL and 100 μg/mL thalidomide is 1.18 and 1.51 respectively. The results reveal that thalidomide could significantly improve radio-sensitivity of glioma U251 cells.  
        关键词：Thalidomide;U251 cell;DNA synthesis;Radio-sensitivity   
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        发布时间：2023-03-30
      • CONG Lihong,ZHU Nankang,TENG Weifang
        Vol. 27, Issue 6, Pages: 374-376(2009)
        摘要：In order to investigate the influence of initially contaminated microorganisms on medical devices for treatment by γ-radiation sterilization, 620 batches of products collected from more than 50 manufactures in Jiangsu, Zhejiang, Shanghai and so on have been inspected by use of ISO11737-1 2006 sterilization of medical devices-microbiological methods-Part 1. The results show that the product batches share is 7.9%, 43.5%, 26.0%, 18.2% and 4.4% with an average bioburden of ≤1.5, 1.5~100, 100~1000, 1000~10000 and >10000 cfu/piece, respectively. These data are helpful to the dose decision for γ-radiation sterilization and quality stability of medical product.  
        关键词：γ-radiation sterilization;Medical devices;Bioburden;Sterilization dose   
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        发布时间：2023-03-30
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