最新刊期
      期 1 ， 1998
      • Xu Yunshu,Song Yongcai,Fu Yibei,Huang Ruiliang
        Vol. 16, Issue 1, Pages: 1-4(1998)
        摘要：Polycarbosilane was irradiated in air by electron beam generated by an accelerator, and then heated to high temperature to produce the SiC ceramics. The results showed that crosslinking bonds including Si-C-Si and Si-O-Si was formed in the irradiated products,and the pyrolysis temperature was consequently elevated from 300℃ of non-irradiated PCS to more than 500℃ of samples irradiated to 2.3 MGy or above. Low molecular weight polycarbosilane and CH4 were detected in the pyrolysis products. The PCS converted to SiC mainly by CH4 release when absorbed dose was above 2.3 MGy.  
        关键词：Polycarbosilane;Radiation treatment;Electron beam;Pyrolysis;Silicon carbide ceramics   
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        发布时间：2023-04-18
      • Wang Huiliang,Chen Wenxiu
        Vol. 16, Issue 1, Pages: 5-9(1998)
        摘要：The gamma radiation induced graft copolymerization of 2, 2, 6, 6-tetramethyl-4-piperidinyl-methacrylate (TMPM) ,a very effective hindered amine light stabilizer (HALS) ,onto polypropylene was investigated by simultaneous-irradiation technique. The effects of various synthesis conditions on the graft content were studied. It was shown that percent grafting in benzene,CCl4 and petroleum ether were higher than that in other solvents. The percent grafting was higher when graft copolymerization was carried out in argon atmosphere than that in air. For the grafting copolymerization carried out in benzene,percent grafting increased linearly from 10 to 60 kGy and beyond 60 kGy a tendency to level off was appeared. In CCl4, percent grafting increased linearly from 10 to 50 kGy and beyond 50 kGy a tendency to level off was appeared. Percent grafting also increased continuously with increasing monomer concentration up to 2.85mol/L, but significant increase was observed only up to 1.14 mol/L. The percent grafting decreased when inhibitor was used,the difference of percent grafting between the samples with and without inhibitor became smaller with the increase of irradiation dose. The stabilizing effectiveness of grafted TMPM on the radiation resistance of Polypropylene was found to be better than that of TMPM monomer.  
        关键词：Radiation induced grafting;Polypropylene;Hindered amine light stabilizer (HALS)   
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        发布时间：2023-04-18
      • Li Jiazheng,Wang Qiang,Zhang Zhicheng,Zhang Manwei
        Vol. 16, Issue 1, Pages: 10-14(1998)
        摘要：The kinetics of γ-radiation emulsion polymerization of vinyl acetate has been studied, and the processing condition has been discussed. The kinetics data and the particle size of latexes showed that in the processing of radiation emulsion polymerization of vinyl acetate,the nucleation period ended earlier (lower than 10% conversion) and the constant rate period was apparent. The particle radius of latexes were in the range of 0.5~3μm,larger than the particles produced by normal emulsion polymerization. The kinetics data also showed that there might be three nucleationmachanism in the polymerization period. A suitable experiment conditionhas thereby been suggested.  
        关键词：Radiation induced emulsion polymerization;Vinyl acetate;Polyvinyl acetate;Nucleation machanism;Latexes   
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        发布时间：2023-04-18
      • Li Wenjian,Zhou Guangming,Chen Weiqiang,Wei Zengquan,Xie Hongmei,Dang Bingrong,Li Qiang,Han Guangwu,Zhang Shumin,Huang Tao,Gao Qingxiang,Yang Hanmin
        Vol. 16, Issue 1, Pages: 15-19(1998)
        摘要：This paper reported dynamic changes of micronuclei and cell survival in human liver cancer cells SMMC-7721 irradiated by 25MeV/u40Ar14+. The results show: (1) Change rules of frequency of micronuclei induced by single irradiation and fractionation irradiation with culture time have not clear difference. (2) Irradiated (single, fractionation) liver cancer cells grow much slower than control and their survival number with culture time shows decay tendency. (3) Dynamic changes of the relationship between micronucleus frequency and cell survival number presents negative correlation. (4) For cells irraddiated by dose of 0.68Gy, 6.8Gy and 68Gy,frequency of micronuclei following culture 24 hours is lower than that following culture 96 hours. (5) Negative dependences of survival number of liver cancer cells for culture 24 hours and 48 hours on dose are demenstrated.  
        关键词：Liver cancer cell;Heavy ion;Micronucleus;Survival number   
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        发布时间：2023-04-18
      • Zhao Yanhua,Xing Ruiyun,Ma Ping,Wang Huichen,Xia Shouxuan
        Vol. 16, Issue 1, Pages: 20-24(1998)
        摘要：Normal HeLa MR cells were irradiated by 60Co γ-ray in the dose range of 0~8Gy and the mutants of hprt gene were cloned in the 6-TG containing selective culture and assayed. Three natural spontaneous mutants and eighteen γ-ray induced hprt mutants were recovered. The mutation spectra of hprt exons in all of them were analyzed by polymerase chain reaction (PCR) using 8 pairs of hprt oligonucleotide primers to amplify hprt exons from cellular DNA extracts. The result showed that in the mutants induced by γ-ray, about 77.8% (14/18) of the hprt mutations were deleted,among which 2 were total deletion, the other 12 were partial deletion,and 22.2% (4/18) ,which did not show noticeable changes in the PCR pattern,were point mutation. The mutation degree of hprt exon deletion was found to be dependent on the irradiation dose. However,about 67% (2/3) point mutants and 33% (1/3) deleted mutants were showed in the natural mutants. Their mutation degree was far lower than that of the γ-ray induced mutants. These r esults might be beneficial for further study of the molecular mechanism of mutation induced by γ-ray irradiation as well as for the estimation of irradiation dose.  
        关键词：γ-irradiation;HPRT gene;Gene mutation spectrum   
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        发布时间：2023-04-18
      • Jiang Jie,Bu Guilan,Wang Bin
        Vol. 16, Issue 1, Pages: 25-28(1998)
        摘要：Kunming mice pre-treated with 50 mGy X-ray or low dose of different concentration MMC were exposed to high concentration MMC or 1.5Gy X-rays. The results showed that the yields of chromosome aberrations of pre-treated groups both in mouse bone marrow cells and germ cells were lower than those of a 1.5Gy group or single high concentration groups. These indicated that there existed a cross-adaptive response induced by low concentration MMC or low dose X-rays,in whole-body mice respectively. The magnitude of the cross-adaptation had a negative relationship with adaptive MMC doses, as well as challenge MMC doses.  
        关键词：Mitomycin C;Ionizing radiation;Germ cell;Bone marrow cell;Chromosome aberration;Cross-adaptation   
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        发布时间：2023-04-18
      • Li Rubing,Wu Qiang,Xu Sujuan,Feng Yan,Luo Houwei
        Vol. 16, Issue 1, Pages: 29-33(1998)
        摘要：In the experiments, the radiosensitization of dihydrotanshinone Ⅰ on human hepatocelluar carcinoma cells QGY-7703 and lung adenocarcinoma cells SPC-A-1 was studied through in vitro colony formation method. The results showed that dihytanshinone Ⅰ has cytotoxity to the two kinds of cells and the LD50 was 7.73μmol/L and 8.86μmol/L, respectively. The compound enhanced the radiation effect. Under aerobic condition the SER (sensitizing ehnancement ratio) of the compound was 1.42 for QGY-7703 cells and 1.62 for SPC-A-1 cells at the concentration of 1μmol/L. The OER (Oxygen enhancemen tratio) for QGY-7703 cells and SPC-A-1 cells was 2.08 and 3.03,respectively. Under hypoxic condition dihydrotanshinone Ⅰ also had radiosensitivity for the two kinds of cells, and the SER of SPC-A-1 cells increased to 1.96 while the SER of QGY-7703 kept 1.42. In split-dose radiation experiment,dihydrotanshinone Ⅰ could inhibit SLDR (sublethal damage repair) obviously at the concentration of 1μmol/L.  
        关键词：Dihydrotanshinone Ⅰ;QGY-7703 cells;SPC-A-1 cells;Sensitizing enhancement ratio (SER);Oxygen enhancement ratio (OER)   
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        发布时间：2023-04-18
      • Zou Zhongmin,Luo Chengji,Guo Chaohua,Shi Yan,Chen Zhaozhen,Li Caian
        Vol. 16, Issue 1, Pages: 34-37(1998)
        摘要：The recovery of hematopoiesis post-radiation injury depends on the proliferation ability of survived bone marrow hematopoietic cells (BMHCs) . In this experiment the proliferation ability of BMHCs of 4~10 Gy γ irradiated mice was studied with the methods of BrdU- incorperation and CFU-GM culture. The proliferation index (PI) declined significantly at 4h post injury and kept at this low level (20% of control) with 48h. The CFU-GM could hardly be detected at 4h after 4~10 Gy radiation, hinting that there might be a phase of colonizing shock early after radiation injury. The data suggest that the proliferation ability of BMHCs is inhibited by irradiation except its direct killing effect,and this might be the basis for drugs of stimulating cell proliferation to accelerate hematopoiesis recovery after radiation injury.  
        关键词：Radiation injury;Hematopoietic cell;Cell proliferation   
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        发布时间：2023-04-18
      • Su Xu,Zhang Yingchun,Liu Shuzheng
        Vol. 16, Issue 1, Pages: 38-41(1998)
        摘要：Kunming mice were wholoe—body irradiated with 0.5~4.0 Gy X—rays. The effeet on different subset of thymocytes were analyzed by flow cytometry with fluorescent monoclonal antibodies 24 hour after irradiation. The results showed that the radiosensitivity varied in different stages of differentiation of the thymocytes. The order of radiosensitivity was: CD4+ CD8+>CD4-CD8->CD4-CD8+>CD4+CD8-,suggesting a relative rad ioresistance of the mature thymocytes. The D37 values of CD4+CD8+, CD4-CD8-, CD4-CD8+ and CD4+ CD8- subsets were respectively 0.76, 0.92, 1.77 Gy and 3.67 Gy. The D37 value of the thymocytes as a whole population was 0.84 Gy. The D37 value of CD3+ cell was 2.0 Gy.  
        关键词：Thymocytes;Differentiation;Radiosensitivity;Radiation effect   
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        发布时间：2023-04-18
      • Xie Feng,Su Xu,Liu Shuzheng
        Vol. 16, Issue 1, Pages: 42-44(1998)
        摘要：Kunming mice were whole body irradiated with different doses of X-rays. Changes of cytosolic-free calcium concentration in thymocytes were measured using Fura-2AM as fluorescent probe. It was found that [Ca2+]i increased 24 h after WBI with 75~100 mGy X-rays. and the increase in [Ca2+]i of thymocytes was fonud to be more marked in the presence of ConA stimulation. The results indicate that low dose radiation can promote signaltransduction of T lymphocytes.  
        关键词：Low dose radiation;Thymocyte;Cytosolic-free calcium concentration;Signal transmission;Fura-2AM   
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        发布时间：2023-04-18
      • Chen Shali,Liu Shuzheng
        Vol. 16, Issue 1, Pages: 45-49(1998)
        摘要：Alterations in transcription factors NF-kB, CREB, AP1, SP1, GRE and OCT1 binding to specific known promoter DNA consensus sequences of immune cells from irradiated and shamirradiated mice 4 hours after whole body irradiation (WBI) with 75 mGy X-rays were investigated with gel mobility shift assay. Increased binding to NF-kB and CREB consensus sequence was found with nuclear extracts prepared from thymocytes and splenocytes of irradiated versus sham-irradiated mice. Protein binding to the NF-kB consensus sequence by nuclear extracts derived from irradiated mice was 5-fold in splenocytes and 4.3-fold in thymocytes higher than that from sham-irradiated. Competition with the cold oligonucleotide containing the consensus suquence for NF-kB resulted in loss of the shifed band at 25-fold excess concentration,indicating specific binding. DNA mobility shift assay using CREB consensus sequence showed 7-fold increace in splenocytes and 6-fold increase in thymocytes after low dose radiation (LDR) . Competition assays using cold oligonucleotide containing the CREB site eliminated the shift band at 50-fold excess concentration. The binding of AP1 consensus sequence showed a 2-fold increase in thymocyte nuclear extracts after LDR. No changes in protein binding to SP1, GRE and OCT1 consensus sequences were noted. The results indicate that activation of selective transcription factors NF-kB,CREB and AP1 of the immune cells in mice occurred after LDR.  
        关键词：Low dose radiation;Immune cell;CREB;NF-kB;Transcriptional regulation   
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        发布时间：2023-04-18
      • Fan Feiyue,Yang Suxia,Cao Zhenshan,Li Yu,Zhou Shuzhen,Tu Kaicheng,Liu Guolian
        Vol. 16, Issue 1, Pages: 50-53(1998)
        摘要：γ-irradiation effects on transformation and DNA strand break of human embryo lung cell were studied by means of cell and molecular biology. The cell transformation appeared at 20 th passage post 0.25~5.0Gy γ-irradiation. The transformation was relative to doses and post-time of irradiation. DNA strand break was detected by NTA (nick translation assay) in this report. The result indicated DNA strand break was arisen from γ ray with different doses. DNA strand break also was relative to radiation doses as cell transformation. Correlation between DNA strand break and cell transformation was analysed. The analysis indicated that effect of cell transformation enhanced with increase of DNA strand break. It was suggested that carcinogensis by radiation is closely relative to DNA damage.  
        关键词：γ-irradiation;Cell transformation;DNA strand break   
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        发布时间：2023-04-18
      • Liu Yongbiao,Su Liaoyuan,Kong Xiangrong,Zhao Yujie
        Vol. 16, Issue 1, Pages: 54-56,49(1998)
        摘要：Effects of elemene on human lymphocyte subsets and its cooperation were studied by method of radioactive compounds incorporation. The results indicated that elemene could increase the radiation resistance of blood lymphocytes or its subsets,enhance the helping effects of cells on B cells and relieve the radiation damage of membrane receptor.  
        关键词：Lymphocytes subsets;Modulate effects;Radiation protection;Elemene   
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        发布时间：2023-04-18
      • Zhang Hongyuan,Wang Yuexing,Wang Lanjin,Pan Yan
        Vol. 16, Issue 1, Pages: 57-61(1998)
        摘要：8 experimental groups were conducted according to four factors two doses orthogonal layout [L8 (27) ] in present investigation. 90 healthy male rabbits and 90 healthy male mice were equally divided into 8 experimental groups and control group. Exprimental animals were exposed to γ-radiation combined with benzene,toluene and CO vapbour for 2h per day,5 days per week for 8 weeks. Two doses of γ-radiation, benzene,toluene and CO were 0.0375 and 0.0075Gy/d (for rabbits, 0.0473 and 0. 0095Gy/d for mice) , 182±33 and 40±15mg/m3, 407±68 and 90±39mg/m3 as well as 278±18mg/m3,respectively. The main results were showed as follows: (1) γ-radiation,benzene and toluene could all induce chromosome aberration,SCEs and micronuclei of lymphocytes in rabbits and chromosome aberrations of bone marrow cells in rabbits and mice,but those was no observed in carbon monoxide. (2) γ-radiation and benzene induced chromosome aberrations and micronuclei of lymphocytes in rabbits as well as chromosome aberrations of bone marrow cells in mice,γ-radiation and toluene induced chromosome aberrations of lymphocytes (in rabbits) and bone marrow cells (in mice) ,benzene and toluene induced chromosome aberations of lymphoytes (in rabbits) and bone marrow cells (in mice) . They showed all significantly interaction. (3) In combined effects,the yield of chromosome aberrations,SCEs and micronuclei induced by ① experimental groups which four factors are all high doses were highest,however, those by induced ⑧ experimental groups which four factors are all low doses also were higher than those of control group and there were statistical difference exdcept SCEs.  
        关键词：γ-radiation;Benzene;Toluene;Carbon monoxide;Cytogenectic effects;Interaction   
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        发布时间：2023-04-18
      • Yang Fengtong,Sun Yuanming,Cui Huishuang
        Vol. 16, Issue 1, Pages: 62-64(1998)
        摘要：The HPRT gene mutation of haemopoietic progenitor cells (GM-CFU) in mice suffered from residual injury induced by single dose and fractional dose 137Cs γ-ray irradiation were investigated. The results showed that the mutant frequency of GM-CFU related closly to the radiation dose. No significant differences were found between single dose and fractional dose irradiation when total dose were 6.0Gy. The radioprotective agent, WR-2721, expressed a obvious protecitive function to HPRT gene mutation of bone marrow GM-CFU in mice.  
        关键词：γ-radiation;HPRT gene mutation;Haemopoietic progenitor cells;GM-CFU   
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        发布时间：2023-04-18
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