最新刊期
      期 1 ， 2007
      • ZHANG Haiwei,HA Yiming,WANG Feng
        Vol. 25, Issue 1, Pages: 1-4(2007)
        摘要：When foods are irradiated, the free fatty acids and triacylglycerides in the food are decomposed to 2-alkylcyclobutanones (2-ACBs), which have been one of the focuses in food irradiation studies since they were discovered in irradiated lipid-containing foods. As specific markers, 2-ACBs could be used to detect irradiated food. The production and stability of 2-ACBs are affected strongly by the irradiation does and temperature and preservation conditions, etc. On the other hand, potential health hazard assessments of 2-ACBs have been studied extensively. Recent progresses in 2-ACBs detecting methods from irradiated food, toxicological studies on 2-ACBs, and factors affecting production and stability of 2-ACBs are reviewed in this paper.  
        关键词：2-alkylcyclobutanones;Radiolytic products;Iradiated food;Detection method   
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        发布时间：2023-03-30
      • LIU Qingjie,CHEN Deqing
        Vol. 25, Issue 1, Pages: 5-9(2007)
        摘要：Rolling circle amplification (RCA) is an isothermal amplification method. The DNA can be amplified exponentially in a short time period. It can be used in detection of rare molecular. RCA is used to amplify not only the circular DNA or RNA, but also linear DNA and even whole genome DNA. At present, RCA is mainly used in fields of whole genome amplification, sequencing, single nucleotide polymorphism, DNA microarray, and protein microarray analysis etc.  
        关键词：Rolling circle amplification;Whole genome analysis;Single nucleotide polymorphism;Microarray   
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        发布时间：2023-03-30
      • YANG Qian,XU Yongjian,ZHENG Zhiming
        Vol. 25, Issue 1, Pages: 10-14(2007)
        摘要：Effect of low concentration negative air ions on Streptomyces avermitilis on solid culture medium was studied. The microorganism was treated consecutively with negative air ions of 5×103/cm3 in 10 days. It was found that under the treatment, Streptomyces avermitilis reached the plat-stage production 4 days earlier than the control. Moreover, quantities of both effective contents of B1a and B1b increased by about 20%, while no remarkable changes in the ineffective contents were observed. Repeated experiments prove that the negative ion treatment is a useful way to shorten long fermentation cycle and to increase antibiotic production.  
        关键词：Negative ions;Streptomyces avermitilis;Avermectin   
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        发布时间：2023-03-30
      • LUO Yan,WANG Dehai
        Vol. 25, Issue 1, Pages: 15-18(2007)
        摘要：Photosensitive resins were UV cured in air or under N2, and surface energy of the cured films were measured. It was found that surface energy of the films cured in air is higher than the films cured under N2. Elemental analysis, ATR-FTIR and XPS analysis were performed. The results show that oxygen inhibition did not result in obvious change in oxygen content of the film cured in air, and the absorption band of peroxide group could not be observed. The surface of the films cured in air were rich in electron-withdrawing groups, whereas the films cured under N2 were rich in carbon single bonds. The different curing atmospheres also resulted in the diversity of binding energy between Cls and O1s atoms on the surfaces. These indicate that different curing atmospheres cause changes in the curing rate, distribution of the compositions and density of the polymer, resulting in differences in chemical composition of the surface and surface energy of the films.  
        关键词：Curing environment;Oxygen inhibition;Element analysis;ATR-FTIR;X-ray photoelectron spectroscopy   
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        发布时间：2023-03-30
      • XIAO Pu,WU Gangqiang,SHI Suqing,NIE Jun
        Vol. 25, Issue 1, Pages: 19-24(2007)
        摘要：Macrophotoinitiators of 1HMPP-TDI-6104, 2HMPP-TDI-6104, 3HMPP-TDI-6104, were synthesized with 2-Hydroxy-2-methyl-1-phenyl-propan-1-one (HMPP), toluene-2,4- diisocynate (TDI), and 6104. The products were analyzed by FTIR spectroscopy. Kinetics for photopolymerization of tripropylene glycol diacrylate (TPGDA) induced respectively by the macrophotoinitiators was studied by photo-DSC, and the initiate effect was compared with HMPP. The results showed that the initiate effects of the macrophotoinitiators were almost the same with HMPP. The polymerization rate and the final conversion were increased by increasing the initiator concentration.  
        关键词：Macrophotoinitiator;Photopolymerization;Kinetics;Photo-Differential scanning calorimetry   
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        发布时间：2023-03-30
      • CHEN Zhuping,WANG Xiuying,PENG Chaorong,XU Sheng,ZHOU Xuemei,WANG Jingxia
        Vol. 25, Issue 1, Pages: 25-27(2007)
        摘要：Polyolefin elastomer was irradiated in air or N2 to different doses by 60Co γ-rays. Gel fraction, mechanic performance and flame retarding property of the irradiated POE were investigated. G value of the POE crosslinked in air or N2 is 0.13 and 0.14, respectively. Gel fraction of the irradiated POE increased with both absorbed dose and sensitizer content, and the value of tensile strength and oxygen index (OI) increased to some extent after irradiation. The value of break at elongation decreased slightly after irradiation.  
        关键词：γ-irradiation;Polyolefin elastomer;Crosslinking;Inflaming retarding   
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        发布时间：2023-03-30
      • LI Qiankun,FU Yuchuan
        Vol. 25, Issue 1, Pages: 28-32(2007)
        摘要：Dosimetry distribution in central axis of inhomogeneous phantoms with small field size beams (beamlets) of 60Co γ-rays and 6–MV X rays were simulated with Monte Carlo code system EGSnrc. The dose enhancement effects and decreasing effects caused by material inhomogeneity were studied dose perturbation factor (DPF), a parameter defined as the ratio of the dose at a point in a heterogeneous phantom to the dose of the same spatial location point in a homogeneous phantom. The results showed that the degrees of the dose enhancement or decreasing depended on energy of the radiation, field sizes of the beamlets and sizes of the phantoms. And this kind of dosimetry change was not linear.  
        关键词：Absorbed dose;Inhomogeneity media;Small beamlets;EGSnrc   
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        发布时间：2023-03-30
      • ZHAO Weiping,ZHANG Hong,QIU Rong,LIU Bing,WANG Yanling,LIU Hui,XIE Yi,YUAN Zhigang
        Vol. 25, Issue 1, Pages: 33-36(2007)
        摘要：Mice were irradiated by 831MeV 12C6+ ions to 0.05, 0.1, 0.3, 0.5, 0.75, 1, 1.5, 2.0Gy, respectively. On 5th day after the irradiation, (Superoxide dismutase, SOD) activity and (Maleic dialdehyde, MDA) content in serum and liver and (Glutathione, GSH) level in brain were determined. The results show that in comparison with the control, the SOD activity in serum and liver increased significantly in groups received less than 0.75Gy, but decreased obviously in groups irradiated to 0.75Gy or larger doses; the MDA content in serum and liver decreased significantly in groups of 0.3Gy or less doses, but increased obviously in groups of 0.3Gy or larger doses; the GSH level in brain tissue increased in groups of less than 0.5Gy, but decreased in groups of greater than 0.5Gy. Therefore, the low dose12C6+ ions irradiation can trigger off the antioxidant system in multi-tissue of mice, while the high doses irradiation can impair the antioxidant system.  
        关键词：12C6 ions;Superoxide dismutase;Maleic dialdehyde;Glutathione   
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        发布时间：2023-03-30
      • SUN Fang,ZHU Guoqiang,DU Hongguang
        Vol. 25, Issue 1, Pages: 43-46(2007)
        摘要：Polysiloxane acrylate oligomer (PSAE), which possesses UV-curing capability and release property, was synthesized by hydrosilyation reaction of polyhydrosiloxane with allyl methylacrylate. The effects of reaction temperature, catalyst concentration and solvent on the reaction were studied. It was found that the optimum synthesis temperature for PSAE was 60—70℃. Tris (Triphenylphosphine) rhodium chloride was used as catalyst with 0.04% of total amount of reactants. Structure of the oligomer was characterized by FTIR. Photosensitive and surface properties of as-synthesized PSAE were investigated. The photosensitivity of PSAE is 56.9mJ/cm2. UV–cured film of PSAE possesses lower surface energy with γdS (H2O) of 32.49mN/m.  
        关键词：Release agent;Hydrosilyation reaction;Acrylate;UV–curing   
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        发布时间：2023-03-30
      • CHEN Shuang,HOU Zhengchi,ZHANG Fengying
        Vol. 25, Issue 1, Pages: 47-50(2007)
        摘要：Cadmium sulfide (CdS) formation on low density polyethylene film (LDPE) grafted with acrylic acid (AAc) was attempted. Films with different degrees of grafting and grafting chain distributions were obtained by using isopropanol/water or methanol/water (volume ratio: 1:1) as grafting solvents respectively and adjusting the monomer concentrations. Different morphologies of CdS were induced on the grafted films. The results indicated that CdS particles grew faster and distributed more thickly on films with higher degrees of grafting. CdS particles formed on films grafted in isopropanol/water system distributed more uniformly than in the methanol/water system.  
        关键词：Polyethylene;Acrylic acid;Radiation grafting;Cadmium sulfide   
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        发布时间：2023-03-30
      • ZHANG Zhiwei,WANG Dan,ZHANG Dongxue,ZHENG Chun
        Vol. 25, Issue 1, Pages: 51-54(2007)
        摘要：Gladiolus corms were irradiated to 100-500kGy by fast neutrons in the CFBR-II pulsed reactor, Scanning electron microscope images of the irradiated samples revealed significant radiation damages to the gladiolus corms, and the mutagenic effects were studied by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Within the dose range, radiation damage to the corm increased with the dose, with corm epidermis of the samples irradiated in vertical incidence being more serious than those irradiated in side-incidence to the same dose. Biological characters were investigated via field experiments, and the bands of protein subunit were analyzed by SDS-PAGE. The results showed that the fast neutrons irradiation inhibited growth of M1 generation seedling significantly. Protein expression was obviously inhibited by the irradiation. The study indicates that fast neutron induction is an effective way for gladiolus breeding. And the results may lay a foundation for studies on fast neutron mutation breeding.  
        关键词：Neutron irradiation;Gladiolus;Scanning electron microscope;SDS-polyacrylamide gel electrophoresis   
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        发布时间：2023-03-30
      • GUO Chuanling,WANG Jufang,JIN Xiaodong,JING Xigang,LI Renmin,LI Wenjian
        Vol. 25, Issue 1, Pages: 55-58(2007)
        摘要：SMMC–7721 and A375 human tumor cell lines were irradiated by 60Co γ-rays, X-rays and 12C6+ ions with different doses up to 6Gy. Dose-survival curves were obtained via colony- formation assays. RBEs of the heavy ions were calculated at different doses. For the two kinds of tumor cells, the RBE of 12C6+ in fractional irradiation was higher than that in single irradiation. The RBE for SMMC–7721 cells were higher than that for A375 cells in both single and fractional irradiation, and the difference became more obvious in fractional irradiation. It is concluded that with special physical properties, the heavy ions are able to efficiently kill tumor cells with high radioresistance, and they can enhance the therapy effect and decrease suffering of the patient.  
        关键词：Heavy ions;Relative biological effectiveness   
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        发布时间：2023-03-30
      • CHEN Yulin,WU Jingbo,SU Xiangdong,TAN Yanqiong,FAN Juan,WEN Qinlian,HUANG Zhendong
        Vol. 25, Issue 1, Pages: 59-61(2007)
        摘要：The work is to report an in vivo experimental study on metal stent-caused damages to esophageal mucosa of pigs under radiofrequency hyperthermia Five points were located for observation, i.e. the middle of the stent, the exit of the stent, 2cm and 4cm under the exit and 4cm above the exit. The stent were placed in esophageal mucosa of 13 pigs and were heated by SR-1000 radiofrequency hyperthermia machine. The esophageal mucosa were observed with naked eyes. And optical microscopy was used to understand the variety of the esophageal mucosa The esophageal mucosa of four temperature checkpoints and observation point were smooth, moist and pale, without any bleeding, erosion and ulcer, while the squamous epithelium of esophageal mucosa of each observation point was normal, with no statistical significance for differences in both the observation results (p>0.05). Therefore, influence of the metal stents on esophageal mucosa could be neglected in radiofrequency hyperthermia. It is safe and feasible to carry out radiofrequency hyperthermia on esophagus placed metal stent.  
        关键词：Radiofrequency hyperthermia;Metal stent;Esophageal mucosa;Pig   
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        发布时间：2023-03-30
      • DONG Xicun,LI Wenjian,YU Lixia,ZHOU Libin,MA Shuang,XIE Hongmei
        Vol. 25, Issue 1, Pages: 62-64(2007)
        摘要：Young shoots of Dahlia pinnata Cav (Daxueqing) cultivar were irradiated by 80MeV/u 12C6+ ions. The as-irradiated shoots were planted in the field of Lintao Flower Corporation in Dingxi City, Gansu Province. Flower color mutant was induced by 8Gy irradiation. Mutant and wild type of Dahlia pinnata Cav were detected for their DNA level differences using RAPD (Random amplified polymorphic DNA) method. The spectra of electrophoresis in agarose gel indicated that among 10 primers used, the 78 bands are produced in 7 primers. Among them 11 polymorphic bands are produced in 5 primers, which substantiated the differences in the DNA level between them. Mutation mechanism by heavy ion beams will be further studied on basis of the results.  
        关键词：Carbon ion beam;Flower color mutant;Dahlia pinnata Cav;Random amplified polymorphic DNA   
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        发布时间：2023-03-30

        研究论文

      • LI Zhenzhong,HE Wei,ZHANG Wenxiong,QU Baojun
        Vol. 25, Issue 1, Pages: 37-42(2007)
        摘要：Three types of ethylene vinyl-acetate copolymer (EVA)/magnesium hydroxide (MH) blends were crosslinked by 60Co γ-irradiation in the presence of trimethylolpropane triacrylate. The influences of irradiation dose on the crosslinking degree and thermal, mechanical and flame retardant properties of EVA/MH blends were studied through the measurements of gel content, Vicat point, limiting oxygen index (LOI), UL-94, tensile testing and the thermogravimetric analysis (TGA). The test results show that the EVA/MH blend with higher vinyl-acetate content in EVA is easier to be crosslinked. The thermal distortion resistance, mechanical and flame-retardant properties of EVA/MH blends are obviously improved by 60Co irradiation. The TGA shows that the thermal stabilities of EVA/MH blends are apparently affected by 60Co γ-irradiation.  
        关键词：γ-irradiation;Crosslinking;Ethylene vinyl-acetate copolymer;Magnesium hydroxide;Flame-retardant   
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        发布时间：2023-03-30
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