最新刊期
      期 2 ， 2001

        研究论文

      • MAHMOUD H M,ARMIA E
        Vol. 19, Issue 2, Pages: 81-91(2001)
        摘要：The study of gamma—ray interactions with matter is increasingly important primarily due to new applications of gamma — emitting isotopes in agriculture, medicine and industry. Two igneous rocks, andesite and felsite, are investigated for radiation shields. The effects of particle size （grain diameter） d mm and sample density ρ on the linear μ, mass µ/ρ attenuation coefficients and side scattering coefficients øs of compressed and natural rocks has been studied with gamma radiation energy E ranging from 0.36 to 1.33 MeV. Flux distribution in samples and the halfvalue layers X1/2 were determined. The resuts showed an inverse proportionality between the linear at¬ tenuation coefficient μ and both d and E. It was also found that μ has a direct proportionality with the sample density ρ. The side scattering coefficient øs is directly proportional to both d and E, but at the same time øs has an inverse proportionality with the sample density ρ.  
        关键词：Gamma — ray attenuation and side scattering coeffcients;Igneous rock sample   
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        发布时间：2023-04-26
      • GE Xuewu,NI Yonghong,LIU Huarong,YE Qiang,XU Xiangling,ZHANG Zhicheng
        Vol. 19, Issue 2, Pages: 118-121(2001)
        摘要：Silver nano — ribbons,with diameters of several tens of nanometers and lengths up to a fwe thousands of nanometers, were successfully prepared by employing urea as a synthetic template under γ ray irradiation. The product was characterized by XRD, ED, and TEM,respectively. The investigation showed that urea played an important role in the formation of silver nano—ribbons.  
        关键词：γ ray irradiation;Silver nanoribbons;Urea;Template—synthesis   
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        发布时间：2023-04-26
      • Lü Xing,XING Ruiyun,PEI Xuetao,LU Ping,SUN Zhixian,WU Zuze
        Vol. 19, Issue 2, Pages: 127-132(2001)
        摘要：The study was done to study was done to investigate the inhibitory role of oncostatin M （OSM） on the melanoma growth as well as the potential application of OSM in the gene—radiotherapy for melanoma in vivo. The human OSM cDNA was inserted into the EcoR I—Xba I site of the vector pCI—neo to form the OSM expression vector (pO). The radiation—inducible OSM expression vector (pEO) was constructed by substituting the CMV promoter in pCI—neo with the regulatory sequence of Egr—1 gene (Egr—1R). The constructs pO and pEO were transfected into mouse B—16 melanoma cells, respectively, and then the OSM secreting cells (pO17 and pEO—1) were selected by anti—h OSM antibldy. An investigation on the tumor weight and comparisons of the inhibition rates between irradiated and non—irradiated tumors were taken. Results showed that the in vivo tumor weights of pO17 and pEO—1 cells were drastically reduced compared to either B—16 or B—neo cells as controls in the same period of twenty days after cells had been inoculated subcustaneously into C57BL/6 mice. It was further observed that for pEO—1 cells, but not for pO—17, there was an increase of 42.3% in the inhibition rate of tumor when tumors were treated with 20Gy of 60Co γ ray radiation. Firstly, the in vivo growth of tumor could be controlled by OSM secreted from OSM gene—modified cells. Secondarily Egr—1R sequence linked upstream to OSM gene could be activated by irradiation and enhance the expression of OSM, and thereby impose an aggravated damage on tumors in vivo, i.e. a gene—radiotherapy effect.  
        关键词：黑色素瘤;抑瘤蛋白M;基因-放射治疗   
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        发布时间：2023-04-26
      • ZHONG Zhijing,LOU Shikai,FU Yibei,LUO Shunzhong
        Vol. 19, Issue 2, Pages: 92-98(2001)
        摘要：127—epoxy resin adhesive and its components: E—44 epoxy resin, dibutyl—o—phthalate and anhydrous ethylenediamine were irradiated with γray in air, nitrogen or vacuum at ambient temperature respectively. The gaseous products such as hydrogen, methane and carbon dioxide were examined by means of GC. Remarkable effect of ambiences and dose on γradiated degradation of these specimen were found. The results indicated that the content of gaseous products increased with dose,but changed with ambiences. The forming of carbon dioxide was not only determined by the amount of oxygen in ambience, but also by whether the specimens struc¬ ture contained oxygenous groups or not. It was shown that there were good linear increasing relationships between dose and the concentration of gaseou products hydrogen and methane for 127—epoxy resin adhesive, and methane for dibutyl—o—phthalate. All above indicated low radiation—resistance of 127—epoxy resin adhesive.  
        关键词：127—Epoxy resin adhesive;γ irradiation;Radiation effect   
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        发布时间：2023-04-26
      • HUANG Wei,FU Yibei,WANG Chaoyang,XU Yunshu,XING Peifeng,WANG Heyi
        Vol. 19, Issue 2, Pages: 99-104(2001)
        摘要：At the room temperature,the radiation effects on polymethyl vinyl siloxane (PMVS) foam were studied in the atmosphere of air,vacuum or inert gas through 60Co γ ray radiation. The unirradiated and irradiated samples were analyzed by FTIR,SEM, PGC/MS and TG. At the same time the gas products after radiation were analyzed by GC/MS. The relationship of compression property and stress relaxation ratio with the radiation dose were determined. The results show that the second crosslinking in the PMVS after chemical crosslinking take place at a low dose (2×105Gy) , but the radiation degradation is predominant when the dose raising. The mechanical property of samples is changed after low dose irradiation.  
        关键词：Polymethyl vinyl siloxane foam;Compression property;Stress relaxation ratio;Radiation effects   
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        发布时间：2023-04-26
      • WANG Huiliang,WANG Chun,CHEN Wenxiu
        Vol. 19, Issue 2, Pages: 105-110(2001)
        摘要：The effects of hindered amine light stabilizers (HALS) on the radiation—in¬ duced discoloration of polyethylene (PE) are studied by measuring the yellowness index (YI) of PE. It is found that all the HALS used are effective in preventing PE from radiation — induced discoloration. The YI of PE added pentamethyl HALS (PMPM, PPMPM) is a little higher than that of PE added corresponding tetramethyl HALS (TMPM, PTMPM) when radiation dose is lower than 100kGy, but when the radiation dose is higher than 100kGy, the YI of PE added pen¬ tamethyl HALS is lower. Pentamethyl HALS is more effective in preventing PE from radiation—induced discoloration when radiation dose is higher. It is also found that polymeric HALS is more effective in preventing PE from radiation — induced discoloration than corresponding monomeric HALS when radiation dose is higher than 200kGy. The formation of alkyl free radical,carbonyl after irradiation is measured. It is found that the relative concentration of free radical formed in PE added TMPM is higher than that of PE added PMPM when radiation dose is relatively high. The carbonyl index of PE containing pentamethyl HALS is less than that of PE containing tetramethyl HALS when radiation is relatively low, but the result is contrary when radiation dose is relatively high. It is believed that HALS prevents PE from radiation — induced discoloration by scavenging free radicals formed in irradiated PE.  
        关键词：Polyethylene (PE);Radiation—induced discoloration;Hindered amine light stabilizer (HALS)   
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        发布时间：2023-04-26
      • ZHOU Hong,WU Ling,NIE Yang,ZHOU Dezhong,DENG Huachuan,DU Yunwu
        Vol. 19, Issue 2, Pages: 111-117(2001)
        摘要：WPC making method that Sichuan birch was impregnated into compound solution mainly consisted of MMA and St/UPE then polymerized by using 60Co γ rays is introduced. Some factors such as the porosity and the density of raw lumber, the condition of impregnation affected the impregnation of WPC were studied. The effects of the MMA St/UPE contents in impregnation solution, the absorbed dose and the polymer loating of WPC were also studied. WPC made by above optimum selection have excellent properties in comparison with its raw lumber: its abrasion resistence, impact indentation was respectively improved by three times,3.7 times. its water absorption and the swelling of wood was respectively reduced by 78.6 percent and 65.6 percent, and antishrink efficiencies was 65.7 percent.  
        关键词：Wood plastic composite;Absorbed dose;Composite impregnating solution;Polymer loating;Antishrink efficicencies   
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        发布时间：2023-04-26
      • WEN Xiaoqiong,LI Qiang,ZHOU Guangming,LI Wenjian,WANG Jufang,WEI Zengquan
        Vol. 19, Issue 2, Pages: 122-126(2001)
        摘要：In order to provide theoretical basis for the homogeneity request of heavy—ion irradiation field,the most important design parameter of the heavy —ion radiotherapy facility planned in IMP (Institute of Modern Physics) ,the influence of the homogeneity of heavy —ion irradiation field on the survival fraction of cells was investigated theoretically. A formula for survival fraction of cells irradiated by the un —uniform heavy —ion irradiation field was deduced to estimate the influence of the homogeneity of heavy —ion irradiation field on the survival fraction of cells. The results show that the survival fraction of cells irradiated by the un—uniform irradiation field is larger than that of cells irradiated by the uniform irradiation field, and the survival fraction of cells increases as the homogeneity of heavy —ion irradiation field decrease. Practically, the heavy—ion irradiation field can be treated as uniform irradiation field when its homogeneity is better than 95%. According to these results, design request for the homogeneity of heavy —ion irradiation field should be better than 95%. The present results also show that the agreement of homogeneity of heavy —ion irradiation field must be checked while comparing the survival fraction curves obtained by different laboratory.  
        关键词：Heavy —ion;Homogeneity of irradiation field;Survival fraction of cells;Influence factor   
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        发布时间：2023-04-26
      • JIANG Shichun,WU Jianping,BAI Hua
        Vol. 19, Issue 2, Pages: 133-137(2001)
        摘要：This paper reported the results of mutagenesis by nitrogen plasma radiation with energy from 65 to 80 keV and dose from 9.6×109 to 1.5×1011/cm2 in antineoplastic antibiotics daunorubicin—producing S. Coeruleorubidus. The relationship between death rate and radiation dose was formulated by computer and the formula. It was fit to a biological single — hit curve. The obtained high—producing mutagenic strain 137 was tested for its production property. The result showed that it could increase the daunorubicin potency by 25.8% in productive tanks of fermentation.  
        关键词：Plasma radiation;Daunorubicin — producing;S. Coeruleorubidus;Death rate;High—producing strain   
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        发布时间：2023-04-26
      • HE Shujie,XIE Feng,LIU Shuzheng
        Vol. 19, Issue 2, Pages: 138-143(2001)
        摘要：To measure the changes in DNA binding activity of CREB and the ratio of cAMP/cGMP in thymocytes after whole body irradiation (WBI) with X rays, as well as to discuss the relationship of the activation of CREB with cAMP signal pathway. Changes in DNA binding activity of CREB and the concentration of cAMP and cGMP in mouse thymocytes were respectively assayed by electrophoresis mobility shift assay (EMSA) and competitive protein binding assay. The increased activity of CREB DNA—binding was upregulated after irradiation with larger doses of X rays (0.5-6.0 Gy) , with the upregulation being most significant after irradiation with 2.0 Gy X rays. Following WBI with 0.075Gy, there was only a brief decrease followed by slight increase in the DNA binding activity of CREB, while the decrease in cAMP/cGMP ratio reached the lowest value at 24h. These results suggested that the slight increase in the DNA binding activity of CREB observed after irradiation with 0.075 Gy may not involve the cAMP signal pathway, while the latter was probably involved in the marked increase in the DNA binding activity of CREB induced by WBI with higher doses of X rays.  
        关键词：Whole — body X irradiation;Thymocytes;Transcription factor;CREB;cAMP/cGMP ratio   
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        发布时间：2023-04-26
      • ZHONG Yule,HUANG Junkai,LIU Weiping,LI Jingna
        Vol. 19, Issue 2, Pages: 144-147(2001)
        摘要：Amorphous silicon is amorphous alloy of Si — H. It is random network of silicon with some hydrogen. And its structure has many unstable bonds as weak bonds of Si—Si and distortion bonds of all kinds. The bonds was broken or was out of shape by light and electrical ageing. It induced increase of defective state that causes character of material going to bad. This drawback will be overcome after microcrystallization of amorphous silicon. It was discovered that a—Si: H was microcrystallized by irradiated of electrons with energy of 0.3-0.5MeV, density of electronic beam of 1.3×1019cm-1s-1 and irradiated time of 10—600s. Size of grain is 10—20nm. Thick of microcrystalline lager is 25—250nm.  
        关键词：Irradiation of electron with high energy;Amorphous silicon;Microcrystallization   
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        发布时间：2023-04-26
      • JIN Shunzi,HE Shujie,LIU Shuzheng
        Vol. 19, Issue 2, Pages: 153-157(2001)
        摘要：The effect of X irradiation on CD80 and CD86 expression in peritoneal macrophages of mice irradiated with whole body irradiation (WBI) and in J774A.1 mouse macrophage cells line irradiated was studied with immunohistochemistry (ABC method) . Results showed that the upregulation of CD80 expression induced by WBI and in vitro irradiation with 2Gy X rays appeared earlier than that with 0. 075Gy X rays, but no significant difference was found in the response of CD86 to these doses. The study on the dose—effect relationship showed that the expression of both CD80 and CD86 reached its peak at 0.075 Gy after WBI as well as in vitro irradiation with X—rays. The doses inducing the second peak of CD80 and CD86 upregula¬ tion were higher in the case of WBI in comparison with the in vitro irradiation. The results suggested that the upregulation of expression of B7 molecules after irradiation may be an important factor involved in the enhancing effect of low dose radiation on immunity.  
        关键词：Ionizing radiation;Mouse Peritoneal macrophage;J774A.1 cell line;CD80;CD86   
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        发布时间：2023-04-26
      • LI Wenbing
        Vol. 19, Issue 2, Pages: 158-160(2001)
        摘要：Raw vegetables and fruits carry pathogens. Ingestion of raw vegetables and fruits can cause outbreaks of illness. Ionizing radiation of fruits and vegetables can deactivate pathogens. The usage of ionizing radiation in sterilization of fruits and vegetables is a promising technology that can be used to improve the safety of ready—to —eat fruit and vegetable.  
        关键词：Ionizing irradiation;Eliminate;Fruits;Vegetables   
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        发布时间：2023-04-26

        研究简报

      • ZHANG Zhouen,YAO Side,JIN Yizun,WANG Wenfen,LIN Weizhen,Qian Suping,Lin Nianyun
        Vol. 19, Issue 2, Pages: 148-152(2001)
        摘要：Nitrogen doxide radical （） is known as a nitrogen centered free radical with powerful oxidizing properties. While ntric oxide and nitrous acid were prved to the able to cause mutation of DNA, the affect of radical to DNA has being concerned by many scientists, but its direct result has not been observed. In this work, the reaction of radical oxidizing guanine and guanosine in basic aqueous solution was observed directly by appoication of pulse radiolysis technique. Moreover,the rate constant of the reaction of radical oxidizing guanine at pH 12, has been measured bo be k=1.3×108. But to reaction about radical with deoxyguanosine 5'—phosphate of other DNA bases was detected. It means that radical is a selective radical to oxidize guaine, and that the glucoside, phosphate and their link of DNA take the protective action against oxidation by nitrogen dioxide radical  
        关键词：Nitrogen dioxide radical;Guanine;Guanosine;Pulse radiolysis   
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        发布时间：2023-04-26
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