最新刊期
      期 4 ， 2004
      • DING Yunsheng,ZHANG Zhicheng
        Vol. 22, Issue 4, Pages: 193-196(2004)
        摘要：The in situ intercalated polymerization of vinyl acetate and montmorillonite clays (MMT) was initiated via γ−ray irradiation. Results of X−ray diffraction (XRD) and transmission electron microscopy (TEM) indicate that polyvinyl acetate (PVAC)−montmorillonite clays (MMT) composite was a kind of nanocomposite. Scanning electron microscopy (SEM) testing result shows that the nano−particles of MMT were packaged by PVAC and the capsule particles was formed, so the MMT particles could be better dispersed in the matrix of HDPE when the polyvinyl acetate (PVAC)−montmorillonite (MMT) nanocomposite was melt−blended with HDPE. For the good compatibility of PVAC and HDPE, these capsule particles are also compatible with HDPE. Thermogravimetric analysis (TGA) results show the existence of MMT nano−particles in the HDPE is helpful to increase the thermostability of it, and the mechanical properties of HDPE were improved. Moreover, the PVAC/ MMT/ HDPE nanocomposite exhibit much better water vapor permeation resistance than HDPE.  
        关键词：γ−ray irradiation;High density polyethylene;Polyvinyl acetate;Montmorillonite;Nanocomposite;barrier properties   
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        发布时间：2023-03-30
      • ZU Jianhua,YU chunhui,YAO Side,QIU Shilong
        Vol. 22, Issue 4, Pages: 197-200(2004)
        摘要：The influence of inhibitor concentration on the grafting yield was studied in different grafting system. It was found that different inhibitors had distinct effect on grafting yield in preirradiation or mutual irradiation method. In mutual irradiation method, Mohr,s salt is much weaker than bluestone in inhibiting homopolymerization with the same wt%. At high temperature, the grafting yield decreases with increasing concentration of Mohr,s salt, but increases at low temperature in some range of Mohr,s salt concentration. It can be interpreted that in the presence of Fe2+ diperoxides and hydroperoxides may decompose at low temperature to form radicals which can initiate the grafting.  
        关键词：Radiation−induced grafting;Inhibitor   
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        发布时间：2023-03-30
      • LIU Deqi
        Vol. 22, Issue 4, Pages: 201-204(2004)
        摘要：In the photo−curing dynamic process and the control of photo−oxidation, the selection of excellent photosensitizers is very important. The method of fast filtration photosensitizers and antioxidants has been brought forward in this paper. DPCO is produced from DPCI oxidized by activated oxygen, which is produced by photosensitizers during exposure to light, and the maximum wavelength of DPCO extracted by CHCl3 is 563.0nm. The fast, dependable, simple method of filtration photosensitizers is based on A563, and antioxidants elected according as ΔA563/A563.  
        关键词：Photodynamic therapy(PDT);Photosensitizers;Antioxidants;Filtration;Spectrophotometric method   
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        发布时间：2023-03-30
      • REN Zhonghai,Guo Yalin,LIU Dejun,LIU Xue
        Vol. 22, Issue 4, Pages: 205-208(2004)
        摘要：Grafting copolymerization of acrylic acid onto flax fabrics initiated by plasma has been studied. FTIR spectrum indicate that —COO— group in the grafted flax increase. SEM image shows that grafted flax surface is rougher and heavier. The effects of plasma power, initiating time, grafting temperature and monomer concentration on graft yields are investigated. It is found that the flax surface grafting can be optimized by the follwing processing conditions: 200W of plasma power, 150s of initiating time, 60℃ of grafting temperature, and 40% of monomer concentration.  
        关键词：Flax;Acrylic acid;Plasma;Polymerization   
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        发布时间：2023-03-30
      • LIU Zhaomin,XIAO Hui
        Vol. 22, Issue 4, Pages: 209-212(2004)
        摘要：This experiment adopts preirradiation grafting of NIPA/AAc onto HDPE membrane to prepare a hydrogel of temperature sensitiveness and pH sensitiveness. The paper analyses the influence of absorbing dose, dose rate, monomer concentration, grafting time, solvent on grafting rate. The hydrogel nature of temperature sensitiveness and pH sensitiveness was tested.  
        关键词：Preirradiation grafting;Environmental sensitiveness;Hydrogel;NIPA;AAc   
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        发布时间：2023-03-30
      • RUAN Weiqing,QIAO Jinliang,HUANG Yuli,NIU Aijie
        Vol. 22, Issue 4, Pages: 213-218(2004)
        摘要：In this paper, three typical acylphosphine oxide photoinitiators (Irgacure 819, Irgacure 1800 and Irgacure 1700) were introduced, and their structure and photolysis mechanism were studied by ultraviolet-visible spectrophotometry. These photoinitiators were used in the synthesis of super absorbent resin (SAR) by UV photopolymerization. The effects of exposure time and content of these photoinitiators on water absorbent properties of SAR were studied. Use Irgacure 1700 as photoinitiator, the water absorbency of the SAR prepared by UV photopolymerization of acrylic acid and ammonium acrylate reaches 835mL/g, and the crosslinking ratio reaches 94.5%.  
        关键词：Acylphosphine oxide photoinitiator;UV photopolymerization;Super absorbent resin;ultravio let-visible spectrophotometry   
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        发布时间：2023-03-30
      • MA Lijun,WANG Tao,ZHANG Lixin,YU Shenyi,HUANG Yuli
        Vol. 22, Issue 4, Pages: 219-223(2004)
        摘要：A novel cationic photoinitiator [Cp−Fe−diphenylether]+PF6- was synthesized and its photoinitiation activity was studied under 700W high−pressure mercury lamp. Compared with I−261, the light absorption above 350nm caused by d−d transition of [Cp−Fe−diphenylether]+PF6- moves to about 360nm and the molar extinction coefficients doubles. Epoxy resin E44, cycloaliphatic epoxides ERL4221 and TDE85 can be photoinitiated by [Cp−Fe−diphenylether]+PF6-effectively. Benzoyl peroxide BPO can promote the photopolymerization of epoxy oligomer initiated by [Cp−Fe−diphenylether]+PF6-, and the photopolymerization rate is higher than that of the SR−1012. post curing of the epoxy system photoinitiated by [Cp−Fe−diphenylether] +PF6- is obvious.  
        关键词：Cationic photoinitiator;[Cp−Fe−diphenylether]+PF6-;Epoxide;Photoinitiated activity;Post curing   
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        发布时间：2023-03-30
      • LIN Yun,ZHU Shifu,ZHAO Beijun,LIN Zhanru
        Vol. 22, Issue 4, Pages: 224-228(2004)
        摘要：In this paper, we present a study on effects of irradiation dose, content and temperature on electromagnetic properties of ferrocene polymer magnet/M type ferrite composites (i.e. OPM/M). Cross−linking and degradation of the materials in their composites were studied by IR differential spectrometry and SEM. The results show that electromagnetic parameters of the materials can be controlled by irradiation dose and content of the composites. It is possible that a new type absorbent of lower density and good absorbing properties will be prepared and used for 0.1 to 12GHz.  
        关键词：Irradiation;Polymer magnet/ferrite composites;electromagnetic parameters   
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        发布时间：2023-03-30
      • FU Chunling,TONG Jian,JIANG Weiwei,ZHANG Junning,HONG Chengjiao
        Vol. 22, Issue 4, Pages: 229-233(2004)
        摘要：SYBR real time RT−PCR method was applied to study the expression profiles of the Growth Arrest and DNA Damage gene 45(GADD45) and p21 induced by X−rays in human peripheral blood lymphocytes in vivo. Results show that GADD45 and p21 gene expressions in human PBLs at 24h after 1, 2, 3, 5Gy X−ray irradiation were increased significantly. A linear dose response relationship could be established for the GADD45 gene expression over the dose range from 1.0Gy to 5.0Gy and for the p21 gene expression over the dose range from 1.0Gy to 3.0Gy 24h after X−ray irradiation respectively. Results suggest that the relative level of the GADD45 and p21 gene expression in human PBLs is dose dependent under the experimental conditions, indicating that the GADD45 gene may serve as a potential biological dosimeter in future radiation accident dose assessment.  
        关键词：GADD45;p21;Gene expression change;Ionizing radiation;PBLs   
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        发布时间：2023-03-30
      • GUO Yuefeng,WANG Mingming
        Vol. 22, Issue 4, Pages: 234-236(2004)
        摘要：Pregnant rats in 11d and 16d of their pregnancy were given one−off whole body exposure by 137Cs γ rays to 0.2, 0.4, 0.9 and 2.0Gy, respectively. Changes were observed in conditioned drinking response and cerebrum hippocampi cone cell number of the baby rats exposed to the γ rays in different periods of their embryo development. As a result, that pregnant rats exposed to 137Cs γ rays in different pregnant periods may induce significant decrease in cerebrum hippocampi cone cell number and achieving rate of conditioned drinking response of the babies. The dose−response relationship can be described by Y = a−b log10 D. The achieving rate of conditioned drinking response were significantly correlated to cerebrum hippocampi cone cell number in the babies, and the achieving rate of conditioned drinking response of the babies exposed at pregnant 11d was lower than others exposed at pregnant 16d.  
        关键词：Pregnant periods;Brain development;Dose−response relationship   
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        发布时间：2023-03-30
      • WANG Mingming,CHEN Ying,DUAN Zhikai,ZHENG Siying,ZHANG Shuxian,XU Honglan
        Vol. 22, Issue 4, Pages: 237-242(2004)
        摘要：To study effects of long term radiation hazard and explore the possibility of the application of chromosome aberration and FISH method to dose retrospection and reconstruction, FISH method was used to detect biological destination of three accidental victims at 7.5 years after Xinzhou accident. In the meantime, conventional chromosomal aberration, G-banding, CB micronuclei and HPRT gene locus mutation assays were performed. In addition, the growth and development of Victim S, who suffered the radiation accident as a fetus, were examined. And comparison of dose estimations between chromosome aberration and FISH method of the victims was conducted. The results demonstrated that the biological dose estimated by translocation frequency is very close to the imitated dose by the physical way after the accident if enough cells are observed. It is suggested that FISH may be applied to dose retrospection and reconstruction. Obvious chromosomal aberrations still existed in the examined victims at 7.5 years after the accident and displayed good dose correlative dependence. The results also showed that the growth and development of S were basically normal after birth.  
        关键词：Fluorescence in situ hybridization (FISH);Conventional chromosome aberration;Accidental victims;Dose estimation   
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        发布时间：2023-03-30
      • LIU Yongbiao,ZHAO Jie,LIU Ying,HAO Xingzhi,WANG Xu,YAO Side
        Vol. 22, Issue 4, Pages: 243-248(2004)
        摘要：In this paper the effect of injury of SOD on lipid peroxidation of tumor cell, telomerase activities in tumor tissues, expression of protooncogene c−Jun pretein were been studied with irradiated tumor−bearing mice. It has been found that content of MDA increased in S180 sarcom group and Lewis lung cancer group in situation of SOD injury while the content of GSH, GPX and activity of T−SOD decreased For former and with no change of GSH for later. It has also been found that SOD can reduce the telomerase activities in S180 and H22 and expression of protooncogene c−Jun in S180 sarcom, Lewis lung cancer tumor tissues. The radiosensitivity of SOD may have some relationship with the effect on expression of protooncogene c−Jun and telomerase activities, and metabolism of SOD in different kinds of tumor.  
        关键词：Superoxide dismutase;Tumor−bearing mice;Radiosensitivity;Rotooncogene c−Jun;Telomerase   
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        发布时间：2023-03-30
      • WANG Xiaomei,JU Guizhi,MEI Shujiang,FU Shibo,LIU Shuzheng,QU Yang
        Vol. 22, Issue 4, Pages: 249-252(2004)
        摘要：To investigate the effect of ionizing radiation on p16 gene transcription and protein expression of thymocytes and splenocytes in mice. Northern blot was applied to determine p16mRNA level. Flowcytometry (FCM) was employed to measure p16 protein expression. The time−course experiments showed that p16mRNA level was markedly increased at4—24h in thymocytes and at4—8h in splenocytes, and p16 protein expression increased significantly at 8—48h in thymocytes (p<0.05—p<0.01) at 24h in splenocytes (p<0.05) after 2.0Gy whole body irradiation with X−rays. The dose−effect experiments showed that p16mRNA level of thymocytes and splenocytes increased with increasing doses and the p16 protein expression increased significantly, too, when the dose increased from 1.0 to 4.0Gy for both thymocytes and splenocytes (p <0.05—p <0.01). p16 gene transcription and protein expression could be induced by X−rays irradiation, and tendency of the increase varied with the dose and cell type. The results suggested that p16 expression played a critical role in G1 arrest induced by ionizing radiations  
        关键词：X−rays;G1 arrest;p16   
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        发布时间：2023-03-30
      • MENG Qingyong,GAO Lili,XU Meiyi
        Vol. 22, Issue 4, Pages: 253-256(2004)
        摘要：To investigate the adaptive response of low doses of gamma−rays to challenge doses of Mitomycin C(MMC) on the splenic lymphocytes in mammalian, mice were irradiated with inductive doses of 50, 75, 100mGy 6h before challenge dose of MMC (1mg/kg). Observations were made on efficacy of splenocyte count, cell cycle progression, DNA synthesis in number of splenocytes, Flow cytometry, the splenic lymphocyte transformation induced by Con A and LPS. The number of splenocytes in Group B(1mg/kg of MMC) was significantly lower than that the control(Group A). The number of splenocytes in Group C, D and E (50−100mGy + MMC) was significantly higher than that in Group B. Both the percentages of G0/G1 and S phase cells in Group D and E were lower and higher than that in Group B in cell cycle progression of the splenic lymphocyte transformation induced by Con A. Significant changes of the numbers were found in the LPS treated groups (except G0/G1 phase of Group E). The results showed adaptive response of low doses of γ−rays to challenge doses of MMC on number of splenocytes and cell cycle progression of the splenic lymphocyte transformation induced by Con A and LPS in mice.  
        关键词：Low dose γ−rays;Mitomycin C;Adaptive response;Cell cycle progression;Splenic lymphocyte transformation;Mice   
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        发布时间：2023-03-30
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