最新刊期
      期 6 ， 2010
      • LEI Jixiao,NI Jin,SHEN Jianliang,CAI Jianming
        Vol. 28, Issue 6, Pages: 321-324(2010)
        摘要：Zebrafish (Danio rerio) as a vertebrate model system has been used in a series of biomedical experiments by scientists. It offers distinctive benefits as a laboratory model system, especially for embryonic development, gene expression, drug screening and human disease model. In this paper, the typical radiation modifiers, such as Amifostine, DF-1, AG1478, Flavopiridol and DNA repair proteins involved in biomedical process by use of zebrafish have been reviewed.  
        关键词：Zebrafish (Danio rerio);Model system;Free radical scavenger;Radio-protective effect;Antioxidant   
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        发布时间：2023-03-30
      • PENG Chaorong,WANG Jingxia,NI Maojun,LIU Siyang,CHEN Zhuping,ZHANG Jing,HUANG Ke
        Vol. 28, Issue 6, Pages: 325-328(2010)
        摘要：Copolymer of poly (L-lactic acid) (PLLA) grafted with N-vinylpyrrolidone (PLLA-g-PVP) was prepared by γ-irradiation in the presence of methanol as a solvent. The effects of acetic acid (HAc) concentration, monomer concentration and dose rate on molecular weight of PLLA-g-PVP were investigated and the structure of PLLA-g-PVP was characterized by 1H-NMR, FT-IR and TGA, respectively. It shows that, the HAc concentration, monomer concentration and dose rate have an effect on the molecular weight of PLLA-g-PVP at the same absorbed dose. The maximum molecular weight of the copolymers can be obtained in optimum condition of HAc concentration 0.05mol/L, monomer concentration 30% and dose rate 500 Gy/h, respectively. The two weight loss stages of graft copolymers have been observed more distinctly with the increment of graft ratio.  
        关键词：γ-irradiation;Poly (L-lactic acid);N-vinylpyrrolidone;Grafting   
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        发布时间：2023-03-30
      • CHEN Qun,ZHENG Yifeng,CAO Changqing,WANG Min,WANG Yonghui
        Vol. 28, Issue 6, Pages: 329-332(2010)
        摘要：Microcrystalline cellulose-graft-Acrylamide (MCC-g-AM) was synthesized by 60Co γ-rays pre-irradiation method. The effects of various reaction conditions on the grafting degree and the utilization ratio of acrylamide were studied. The structures of the grafted copolymers were characterized by Fourier transform infrared spectroscopy (FT-IR). The highest grafting degree and utilization ratio of acrylamide were more than 65%, which was obtained at reaction time of 3 h, pre-absorbed dose of 35 kGy, reaction temperature of 40℃, MCC/AM mass ratio of 0.5:1, Fe(NH4)2(SO4)2·6H2O/AM mass ratio of 0.01%, and AM monomer concentration of 5%.  
        关键词：Microcrystalline cellulose (MCC);Acrylamide;Pre-irradiation graft   
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        发布时间：2023-03-30
      • ZHAO Yanqiao,LI Jianying,DENG Yu,WANG Wenzhong
        Vol. 28, Issue 6, Pages: 333-338(2010)
        摘要：Hydrogen peroxide bleaching processes of wheat straw pulp by microwave radiation in water bath were investigated. The effects of microwave power, process time, H2O2 dosage and NaOH dosage on the quality of the bleached pulp were investigated. And the experiment conditions were optimized by using the method of orthogonal test. The form of the pulp fiber was measured by fiber analysis. The best process conditions for hydrogen peroxide bleaching process of paper pulp by microwave radiation could be made in condition such as microwave power was 240 W, process time was 2.5 min, H2O2 dosage was 5% and NaOH dosage was 4.5%. In optimal process, the whiteness of paper pulp could reach about 59%ISO. The fiber analysis indicated that the form of the pulp fiber did not vary from that before reaction. The results showed that microwave radiation in stead of water bath was good for H2O2 bleaching process of paper pulp.  
        关键词：Microwave radiation;Hydrogen peroxide;Bleaching   
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        发布时间：2023-03-30
      • LIN Hui,WU Dongsheng,XU Yuanying,JING Jia,XU Liangfeng
        Vol. 28, Issue 6, Pages: 339-344(2010)
        摘要：It is very important that the stochastic characteristics of the absorbed energy affect the energy deposit and its radiobiological effect of ionization radiation at cell or cell cluster scale. This work built the specific code for microdosimetric quantities based on Geant4 toolkit, and studied the α-emitter 211At microdosimetric characteristics of a simple cell model and a virtual cell model. The feature of the single event specific energy and the survival fraction for different cell dimensions was investigated. A virtual digital cell model was implemented and its microdosimetric characteristics were studied. The influence of different materials and irregular configuration on the microdosimetric quantities was analyzed by comparing with those of the simple cell model. A Geant4 utility code for voxel-based single cell models was built for the microdosimetric research of single cell model, which is also easy to extend to the voxel-based tissue model.  
        关键词：Microdosimetry;Monte Carlo;Simple cell model;Virtual cell model   
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        发布时间：2023-03-30
      • DIAO Jinshan,WANG Li,CHEN Zhen,LIU Hui,NIE Guangjun,ZHENG Zhiming
        Vol. 28, Issue 6, Pages: 345-351(2010)
        摘要：Low-energy N+ implantation was employed to mutate Aspergillus niger Au to enhance productivity of β-glucosidase. Effects of N+ on strains, survival and mutation rate were studied. After several rounds of implantation, activity of β-glucosidase of the final mutant Au 0847 reached 13.75 U/mL, which is higher by 106.8% than that of original strain Au, and its heritability was stabilized. Activity of β-glucosidase of Au 0847 reached 30.53 U/mL after further fermentation condition optimization.  
        关键词：β-glucosidase;Ion implantation;Aspergillus niger;Breeding;Fermentation optimization   
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        发布时间：2023-03-30
      • YANG Wei,YIN Xiaoxiang,CAO Jianping,LIU Fenju
        Vol. 28, Issue 6, Pages: 352-356(2010)
        摘要：In order to investigate the effect of RNA interference silencing survivin gene on radio-sensitivity of human hepatoma SMMC-7721 cells, mRNA and protein expression of survivin gene in SMMC-7721 cells after transfection with pGenesil-survivin-HIF mediated by liposome were detected by RT-PCR and western blot respectively. Cell viability was detected by MTT assay. Cell cycle distribution and apoptosis of SMMC-7721 cells were detected by FCM assay. Radio-sensitivity of SMMC-7721 cells was determined by clonogenic assay. The results showed that mRNA and protein expression of survivin gene in SMMC-7721 cells was significantly lower than that of control and negative interference group 48 h after transfection with pGenesil-survivin (p<0.05). Cell viability of pGenesil-survivin group was significantly lower than that of control group (p<0.05 or P<0.01). Cells arrested in the G2/M phase of cell cycle (p<0.001) and percentage of apoptosis was significantly higher than that of control group 48 h after transfection with pGenesil-survivin (p<0.001). D0 of SMMC-7721 cells after transfection with pGenesil-survivin decreased and its radio-sensitivity increased. The radio-sensitization ratio was determined to be 1.24. These results can be suggested that silencing survivin gene enhances radio-sensitivity of human hepatoma SMMC- 7721 cells.  
        关键词：RNA interference;Survivin;Hepatoma;Radio-sensitivity   
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        发布时间：2023-03-30
      • WANG Mingming,SI Yuan,QIU Jun,XIE Qiang,XIE Jikui
        Vol. 28, Issue 6, Pages: 357-362(2010)
        摘要：The influence of 18F-FDG on the proliferation of HepG2 liver cancer cell was investigated and related possible mechanism was elucidated in this paper. HepG2 liver cancer cells were conventionally cultured. The cells during the phase of logarithmic growth were divided into different groups of 18F-FDG treatment and control groups. At 6,12 and 24h after treatment of 0—92.5×106Bq/mL of 18F-FDG, inverted microscopy, the cell apoptosis was analyzed by use of flow cytometry and reverse transcription-polymerase chain reaction to analyze meanwhile the content of reactive oxygen species (ROS) and expression of p53 gene in cells induced by 18F-FDG, were determined respectively. After exposure to 18F-FDG, the apoptotic morphological changes of HepG2 liver cancer cells were observed. It was found that inhibition rate of cell proliferation, production of ROS and apoptosis rate increased with the radioactivity concentration of 18F-FDG in the range of 0—92.5×106Bq/mLwhile the expression of p53 gene increased gradually. The results indicate that 18F-FDG may inhibit the proliferation of HepG2 liver cancer cells by apoptosis and increment of inhibition rate.  
        关键词：18F-2-Deoxy-2-Fluoro-D-Glucose (18F-FDG);HepG2 liver cancer cell;Cells proliferation;Apoptosis   
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        发布时间：2023-03-30
      • LU Xue,ZHAO Hua,CHEN Deqing,FENG Jiangbin,LIU Qingjie,SU Xu
        Vol. 28, Issue 6, Pages: 363-367(2010)
        摘要：In order to explore the probability of PCC-ring (PCC-R) in G2/M-PCC cells could be used to quantify the extent of ionizing radiation damage, premature chromosome condensation (PCC) induced by Calyculin A was analyzed. Peripheral blood samples were irradiated with 0, 4, 8, 12, 16 and 20 Gy 60Co γ-rays. The PCC-R, which was induced by Calyculin A after culture of 48 h, was observed in the samples exposed to different dose of 60Co γ-rays. The G2/M-PCC index and the distribution of PCC-R were calculated; the dose-response curves between the frequency of PCC-R and exposed dose level were established. The results showed that PCC was successfully induced by Calyculin A. The G2/M-PCC index decreased with exposed dose level. The PCC-R distribution followed a Poisson law for most of dose levels except 20 Gy. The frequency of PCC-R increased with the exposed dose level. And the dose-effect curve between the frequency of hollow-, kidney-shape ring and exposed dose level was fitted with two models, a linear model y=0.0128x−0.0104 R2=0.9898 and a non-linear model y=0.00002x2+0.0085x+0.0011 R2=0.9996. The frequency of PCC-R in peripheral blood lymphocyte G2/M-PCC cells induced by Calyculin A could be used to quantify the extent of ionizing radiation damage.  
        关键词：Ionizing radiation;Lymphocyte;Premature chromosome condensation;Calyculin A;PCC-ring   
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        发布时间：2023-03-30
      • YU Jingping,SUN Meiling,SUN Suping,YIN Xiaoxiang,LIU Haiyan,ZHANG Haowen,FENF Shuang,LIU Fenju
        Vol. 28, Issue 6, Pages: 368-372(2010)
        摘要：In order to investigate the inhibition of DNA synthesis and the mechanism of thalidomide enhanced radio-sensitivity on glioma U251 cells, survival rate of the cells was assessed by MTT assay; and 3H-TdR incorporation assay was used to investigate the inhibition of DNA synthesis by thalidomide alone and combined with X-rays; VEGF mRNA expressions were evaluated using RT-PCR assay. Protein expression (VEGF) was detected by Western blot analysis. Thalidomide inhibited DNA synthesis depending on the concentration of thalidomide and radiation dose. Thalidomide markedly down-regulated VEGF mRNA combined with X-rays in which a synergistic action appeared. Low dose X-rays can induce VEGF protein expression in 24 h. Thalidomide was a low toxicity to U251 cells. Thalidomide inhibited DNA synthesis of U251 cells.  
        关键词：Thalidomide;Glioma U251 cells;DNA synthesis;Vascular endothelia growth factor (VEGF)   
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        发布时间：2023-03-30
      • CHEN Feng,TU Yu
        Vol. 28, Issue 6, Pages: 373-376(2010)
        摘要：In order to investigate the effect of γ-rays on neurodevelopment of fetal brain tissue as bystander effect organ, pregnant Kunming mice were randomly divided into blank control group, 0.5 Gy whole-body exposed group, 0.5 Gy head exposed group, 1.0 Gy whole-body exposed group, 1.0 Gy head exposed group, 2.0 Gy whole-body exposed group and 2.0 Gy head exposed group. The exposed mice were exposed with a vertical single acute dose using 60Co therapy apparatus on 9 th day of pregnancy, and cesarean operation were performed to gain fetal mice on 18 th day of pregnancy. Then the levels of AchE and Ach were detected using ELISA kit. Compared with the blank control group, the levels of Ach in 0.5 Gy and 1.0 Gy head exposed groups were decreased (p<0.05); the levels of AchE and Ach decreased in 2.0 Gy whole-body and head exposed groups (p<0.05); the level of Ach in 0.5 Gy whole-body exposed group increased (p<0.05). And bystander effect in fetal brain tissue was induced by ionizing radiation in head exposed groups, which was similar with that in the whole-body exposed groups.  
        关键词：Ionizing radiation;Fetal brain;AchE;Ach;Bystander effect in vivo   
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        发布时间：2023-03-30
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