最新刊期
      期 1 ， 2002
      • XU Gang,LIANG Hongbo,SHI Wenfang
        Vol. 20, Issue 1, Pages: 1-6(2002)
        摘要：This article summarized the principium of food irradiation processing, and also described the marketing status with the technology in Europe and America.  
        关键词：Food;Sterilization;Irradiation processing   
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        发布时间：2023-04-07
      • PENG Chaorong,WANG Xiuying,CHEN Zhuping,ZHOU Xuemei,DENG Huachuan,ZHOU Yingcai
        Vol. 20, Issue 1, Pages: 7-11(2002)
        摘要：The HDPE/EEA composition of different co—crystallization was crosslinked by 60Co γ rays. The effect of co—crystallization on PTC properly of multivariate composition in polymer was investigated in the paper. The results showed that the co—crystallization of the multivariant composition could improve the PTC anomaly and thermal stability,but it didn't take dominant effect on recoverability of switch temperature.  
        关键词：co—crystallization;Positive temperature;Coefficient radiation crosslink   
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        发布时间：2023-04-07
      • LUO Shikai,FU Yibei,LUO Shunhuo,LONG Xinping,HUANG Yigan
        Vol. 20, Issue 1, Pages: 12-18(2002)
        摘要：After irradiation of F2311 by γ ray (50—1000kGy) in vacuum, nitrogen and air, its average molecular weight, tensile strength and breaking elongation decreased as irradiation dose increased. But the gel fraction at first decreased and then increased with the increment of dose, on the dose of 750kGy the minimum value has been obtained. The changes of glass transition temperature and modulus are similar to that of the gel fraction. The IR analysis of sample indicated the formation of — CF=CH —, — FC=CF — and — C=O groups. Microstructures for irradiated samples were studied by SEM. Results showed that air promoted the irradiation degradation of F2311 and nitrogen inhibited that of it in a certain extent.  
        关键词：Fluororubber F2311;γ ray;Radiation degradation   
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        发布时间：2023-04-07
      • CHENG Kemei,FENG Wen,YAO Side,QIAN Suping,YUAN Lihua,HUANG Su
        Vol. 20, Issue 1, Pages: 19-26(2002)
        摘要：Reaction of p—tert—oxocalix [4]arene in cyclohexane at 308nm laser light was investigated by laser photolysis technology at room temperature in research of the reason why p—tert— oxocalix [4]arene was used as polymer stabilizer. Four main absorption were observed at 300nm,340nm,460nm and 540nm. Among them 300nm and 460nm were assigned to the absorption of phenoxy radical and cationic radical respectively. Solvent and pH dependence of cationic radical were investigated. Two—photon process mixed with one — photon process was suggested on the OH bond dissociation. The conclusion was draw that the produce of the relative stable phenoxy radical mediate when p—tert—oxocalix [4]arene was excited is one of the reason.  
        关键词：P—tert—oxocalix [4] arene;Laser photolysis;Phenoxy radical;Cationic radical;Photonic ionizatio   
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        发布时间：2023-04-07
      • ZHANG Fugen,WU Jilan
        Vol. 20, Issue 1, Pages: 27-34(2002)
        摘要：γ irradiated rutin —, catechin — and baicalin — HCOONa aqueous solutions saturated with N2O:O2=4: 1 were eluted through alumina columns and the G values of hydrogen peroxide generated in the solutions were measured. Different results from former works were obtained and the reasons of the difference were discussed. A precise method was established as follows: hydrogen peroxide should be separated from flavonoids by passing the flavonoids solutions through alumina columns before the measurement and the amount of hydrogen peroxide generated from self—oxidation of the flavonoids should be deducted. The G values of hydrogen peroxide in γ irradiated rutin —, catechin — and baicalin — aqueous solutions saturated with N2O:O2=4:1 were determined to be 8.3±0.2, 5.6±0.2, and 7.8±0.2, separately.  
        关键词：Rutin;Baicalin;Catechin;Hydrogen peroxide;Irradiation   
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        发布时间：2023-04-07
      • ZHANG Youjiu,ZHU Nankang,WANG Chunlei
        Vol. 20, Issue 1, Pages: 35-39(2002)
        摘要：The effects and its interaction mechanism of Salviae Miltiorrhizae (SM) on aging properties of RVNRL films were studied. The results show that SM can effectively improve RVNRL films aging properties. SM—a is the best aging agent among SM, SM—w and SM—a. The content of 1.5g SM—a(c—99) /20gRVNRL is suitable to improving aging properties of RVNRL films. It was found that aging properties of SM—a coming from different regions are different and aging property of SMs and their scavenging hydroxyl radical ability are consistent.  
        关键词：Salviae Miltiorrhizae;RVNRL film;Aging;Hydroxyl radical;ESR   
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        发布时间：2023-04-07
      • GAO Jianjun,GAO Linfeng,JIN Weifang,WANG Hongfu,WEI Daolin,LI Lingbo,GAO Yanhong,ZHOU Yi
        Vol. 20, Issue 1, Pages: 40-46(2002)
        摘要：To study the influence of radiation on osteoblasts and osteoclasts in vitro. 137Cs γ rays was used to irradiate the rat calvaria — derived osteoblasts and femur — derived osteoclasts. The changes in morphology, proliferation rate,ALP activity,mineralized nodules forming capacity and osteocalcin mRNA levels of irradiated—osteoblasts and osteoclastic apoptosis rate were detected respectively. Degenerative changes in morphology was observed and the inhibitory effects on osteoblasts proliferation rate by radiation was correlated with dose and ALP activity was also decreased by 28%. The nodules numbers was increased by 91.75% in lower—dose(0.5—1Gy) and decreased by 67.13% in higher — dose (6Gy). Osteocalcin transcription levels were 1.46 in 6Gy and 2. 75 in control. The osteoclastic apoptosis rate was increased with irradiation dose. Low —dosage γ irradiation may accelerate the aging process of osteoblasts and induce osteoclasts apoptosis in vitro.  
        关键词：Radiation;Osteoblast;Osteoclast   
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        发布时间：2023-04-07
      • GUO Wanfeng,GUO Guozhen,HAN Liangfu,DING Guirong,HUI Yanping,GUO Yan,MA Haixin
        Vol. 20, Issue 1, Pages: 55-60(2002)
        摘要：The aim of this paper was to observe bcl— 2 and bax gene expression and apoptosis and to study the correlation between bcl — 2 and bax gene expression and apoptotic index in the samples from patients with cervical squamous cell carcinoma following radiotherapy. Apoptosis was detected with TUNEL method. It was found that the bax gene expression and apoptotic index in cervical carcinoma significantly increased (p <0.05 and p < 0.01, respectively) after 10Gy irradiation compared with those of pre—therapy. However,the bcl—2 gene expression had no obvious change (p>0.05). Our data suggested that the bcl—2 and bax gene cooperative expression was related unobviously with spontaneous apoptosis,but obviously with radiation—induced apoptosis(p<0.05,r=0.5264) in patients with cervical squamous cell carcinoma.  
        关键词：Cervical squamous cell carcinoma;Apoptotic index (AI);bcl—2 gene;Bax gene   
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        发布时间：2023-04-07
      • JIA Shaojin,ZHANG Zhicheng,WANG Zhenzhou,GE Xuewu,DU Zhiwen
        Vol. 20, Issue 1, Pages: 61-66(2002)
        摘要：By blending low —halogen flame — retarding agent with the basic resin and using γ irradiation FR — HDPE/EPDM for cable and wire insulation with 125℃ heat resistance was prepared. The mechanical and electrical measurement showed that radiation crosslinking improves some essential properties of the material, such as the heat resisteance, tensile strength et al. The dynamic flammability of the material was researched by cone calorimeter,it was found that radiation crosslinking decreases both release heat rate and effective heat of combustion while burning, besides,crosslinking increases oxygen index and the residues of combustion though the time to ignition of the irradiated material is somewhat decreased. The work was compared with the tradiational method TG measurment.  
        关键词：Cone calorimeter;Flame retardant;High—density—polyethylene(HDPE);Ethylene—propylene terpolymer;γ irradiated;Dynamical flame   
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        发布时间：2023-04-07
      • ZHOU Yinghui,XU Lan,WU Shiliang,SHI Ning,TU Youbin,PENG Miao
        Vol. 20, Issue 1, Pages: 67-71(2002)
        摘要：To investigate the change of collagen type I and type III and the action of TGF-β1 after high energy electrons radiation. The animal model of radiation injury was established by high energy electrons radiation produced by the linear accelerator; and irradiated NIH 3T3 cells were studied. In the experiment the contents of total collagen,collagen type Ⅰ and type III were measured. The contents of TGF—β1 were also detected. The results showed after radiation,little change was found in the content of total collagen,but the content of collagen I decreased and the content of collagen III increased; the expression of TGF-β1 increased. Changes in the collagen metabolism were caused by the irradiated injury of the skin; TGF—β1 may be essential in the regulation of the collagen metabolism.  
        关键词：Electron;Radiation injury;Collagen;TGF-β1   
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        发布时间：2023-04-07
      • ZHU Guangming,XU Qiangyong,SHI Yongqin
        Vol. 20, Issue 1, Pages: 72-76(2002)
        摘要：The effects of 3 additives (sulfur,trimethylolpropane triacrylate (TMPTA)and petaerythritol tetraacrylate (PETA) on radiation cross — linking of LLDPE — EPDM are investigated in this paper. The gel percentage content,mechanical properties and heat age resistances of the blends with various compositions and radiation dosage have been studied. It can be concluded that all the 3 additives are helpful to the radiation cross—linking of LLDPE—EPDM blends and could approve its properties, but sulfur is the best. Based on the above,the blended materials with tensile strength and elongation above 20 MPa, 500% respectively have been made by LLDPE 100, EPDM 50 — 100,S 0.5 — 2 parts and other additives 30 — 40 parts. These materials also have the characteristics of excellent heat aging, weather resistance, low temperature flexibility and toughness. They can be used for the outer jacketing of wire or cable, pliability and strong heat shrinking products.  
        关键词：LLDPE —EPDM blends;Radiation cross-linking;Cable jacketing;Heat shrinking material   
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        发布时间：2023-04-07
      • LIU Xiaoqiu,ZHAO Wenzheng,ZHAO Ajin
        Vol. 20, Issue 1, Pages: 77-80(2002)
        摘要：By using viable cell count,cell morphology examination and flow cytometry analysis,We studied the effects of γ ray combined with electromagnetic field on HL — 60 cells. Cells were exposed to 4Gy γ irradiation from 137Cs γ ray. The strength and frequency of the electromagnetic field were 10MT and 250Hz respectively. The combined effects of 137Cs irradiation with exposure to the electromagnetic field showed a greater effect than a simple additive one. The results suggest that electromagnetic field can increase apoptosis induction of HL—60 cells by ionizing radiation.  
        关键词：γ ray;Electromagnetic radiation;Apoptosis;HL — 60 cell   
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        发布时间：2023-04-07

        综述

      • GU Qingyang,WANG Dewen,GAO Yabing,ZHOU Jie,PENG Ruiyun,CUI Yufang,XIA Guowei,QIN Quanhong,YANG Hong,LIU Jie
        Vol. 20, Issue 1, Pages: 47-54(2002)
        摘要：A rat model of rediation-combined wound healing was used,and routine light microscopy observation,electron microscopy observation, immuno histochemistry,and in situ hybridization were performed to study MMP1 and TIMP1 expression during the healing process. The wound healing process was impaired and delayed. After irradiation for rats receiving 25Gy Gamma ray locally the irradiated wounds healed 6 days later than non — irradiated controls. The folfowing changes of MMP1 and TIMP1 expression were found: （1） In the early inflammatory phase and in the period of granulation tissue formation,MMP1 expression was only slight,if affected at all in the newly formed epidermis of irradiated wounds. Later,the epidermal expression of MMP1 in radiation wounds was comparatively increased following the delay of the heallng process. From the 3rd day to 14th day after wounding, TIMP1 was weakly positive in the proliferating keratinocytes of control wounds and became negative after epidermal covering, whereas no or only slight epiderma expression was detected in the irradiated wounds before epidermal covering. （2） Compared to controls,MMP1 and TIMP1 expression in irradiated wounds was markedly decreased in fibroblasts,endotheliocytes and macrophages. The expression phase was prolonged due to the delay of the healing process. We conclude that the reduced expression of MMP1 and TIMP1 in granulation tissue of irradiated wounds retards such important processes as cell migration and angiogenesis, and thus slow the healing process. The expression of MMP1 in the newly-formed epidermis may help the process of reepithelialization; but in the late healing period, overexpression of MMP1 and decreased expression of TIMP 1 in the epidermis may hinder the establishment of basal membrane and scar formation.  
        关键词：Irradiation;Wound healing;MMP1;TIMP1   
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        发布时间：2023-04-07
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