最新刊期
      期 5 ， 2006
      • HA Yiming,WANG Feng
        Vol. 24, Issue 5, Pages: 257-261(2006)
        摘要：Effects of irradiation dose, storage time, concentration of oxygen and antioxidants on lipid oxidation in pork samples irradiated at chilling temperatures were studied for seeking technical approaches to control the lipid oxidation. The result indicated that the correlation between the dose and peroxide value (PV) was extremely high (p<0.01). During storage the PV rose first and then decreased. The irradiation could lower the PV and the TBARS value in chilled pork samples in either vacuum-packages or un-aerobical packages. Antioxidant combinations showed distinct beneficial reduction in lipid oxidation. The PV and the TBARS value were under 3meq/kg and 0.4mg MDA/kg respectively during storage, while they were 29meq/kg and 1.13 mg MDA/kg in the control samples. Among all the antioxidants, tea polyphenols and VE play an important part in controlling the lipid oxidation.  
        关键词：Irradiated food;Chilled pork;Lipid oxidation   
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        发布时间：2023-03-30
      • SUN Hanwen,XU Dongmei,MENG Fanzong,WANG Dunqing,HONG Jun,GONG Peijun,XUE Yanling,DONG Li,YAO Side
        Vol. 24, Issue 5, Pages: 271-274(2006)
        摘要：Polyacrylamide-coated magnetic nanogels were synthesized via photochemical polymerization under UV light irradiation. The polyacrylamide-coated magnetic nanogels were characterized by Fourier transform infrared spectroscopy and photo correlation spectroscopy. And it was found that particle size of the polyacrylamide-coated magnetic nanogels increased with the reaction time and the monomer concentration, but decreased with increasing concentration of the cross-linker of N, N’-Methylene-bis-(acrylamide). The coating mechanisms were studied by ESR measurements of different samples of the nanogels.  
        关键词：Polyacrylamide;Photochemical synthesis;Magnetic nanogels;Electron spin resonance spectrum   
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        发布时间：2023-03-30
      • ZHANG Longbin,ZHU Guangming,XU Shuogui,WANG Jinhua,QIN Ruifeng
        Vol. 24, Issue 5, Pages: 275-278(2006)
        摘要：Kinetics of enzymatic degradation behavior of cross-linked PCL was studied. It is well known that the enzymatic hydrolysis of water-insoluble PCL by depolymerases produces water-soluble products. The result showed that the concentration of product in the solution increased with the time and substrates concentration. The degradation kinetics followed Mechaelis-Menten equation. The degradation parameter of the PCL powder was 1.14mg/mL for Km and 0.39mL/h for Vmax, respectively. And the degradation parameter of cross-linked PCL particulate was 71.95mg/mL for Km and 0.96mL/h for Vmax, respectively.  
        关键词：Polycaprolactone;Enzymatic degradation;Kinetics;Titrimetry   
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        发布时间：2023-03-30
      • HONG Jun,XU Dongmei,GONG Peijun,YU Jiahui,SUN Hanwen,YAO Side
        Vol. 24, Issue 5, Pages: 279-282(2006)
        摘要：In this paper, particle size-controllable carboxyl-functionalized magnetic nanogels were synthesized via photochemical in situ polymerization. Effects of system pH value, volume of monomer dropped irradiation time and chain transfer agent on the particle size of the carboxyl-functionalized magnetic nanogels were detailedly investigated.  
        关键词：Carboxyl-functionalized;Photochemical in situ polymerization;Magnetic nanogels;Controllable synthesis   
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        发布时间：2023-03-30
      • LUO Yan,WANG Dehai,CAI Yanqing
        Vol. 24, Issue 5, Pages: 283-288(2006)
        摘要：The influence of various monomers on the surface energy of the UV cured films was investigated. The results show that: chemical nature of the monomers affects different surface energy of the films. The value of surface energy for the film containing 9EOTMPTA is the highest, whereas the film containing POTMPTA has the lowest value among four investigated tri-functional monomers. 9EOTMPTA has relatively higher content of ether groups, and POTMPTA has more methyl groups. ATR-FTIR analysis also indicates that the content of ether groups on the film surface which contains 9EOTMPTA is higher than that containing POTMPTA. And the results of surface energy of the films agree with the surface tension of the monomers. That is the higher surface tension of the monomer, the higher surface energy of the film, and vice versa. Besides, the surface energy of the films drops when the dosage of the tri-functional monomers increases. It is also found that the bifunctional monomers decrease the surface energy of the films.  
        关键词：Monomer;Surface energy;Polarity;Functional group;Attenuated total reflectance–Fourier transform infrared spectroscopy   
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        发布时间：2023-03-30
      • GAO Hong,NIE Jun
        Vol. 24, Issue 5, Pages: 289-292(2006)
        摘要：Generally, the temperature had great influence on the photopolymerization kinetics. However, few attentions were paid to the photopolymerization induced at low temperature. In this study, the solid-state system of 1, 6-hexanediol diacrylate (HDDA)/2-hydroxyl-2-methyl-1- phenyl-propane-1-one (1173) was photopolymerized at low temperature, the near infrared spectroscopy (NIR) and electron spin resonance (ESR) were employed to monitor the photopolymerization kinetics and the post-curing reaction of this system. Although the solid-state 1, 6-hexanediol diacrylate could be photoinitiated by 1173, the double bond conversion was low. The post-curing reaction could improve the double bond conversion. And the free radical was still alive after 4 h when light turned off. The photopolymerization kinetics was greatly affected by polymerization temperature. Increasing the curing temperatures caused the increase of the double bond conversion. The optimum concentration of 1173 was 0.4% for reaching high rate of polymerization and double bond conversion. However, the excessive photoinitiator decreased the rate of polymerization and double bond conversion.  
        关键词：1;6-Hexanediol diacrylate;Solid-state;Photopolymerization;Post-curing   
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        发布时间：2023-03-30
      • ZHANG Yan,XIE Leidong,LI Linfan,FU Haiying,SHENG Kanglong
        Vol. 24, Issue 5, Pages: 293-297(2006)
        摘要：Based on studies at SINAP on radiation-induced graft copolymerization of styrene-butadiene-styrene (SBS) copolymer with maleic anhydride (MAH), Maleic anhydride/styrene (MAH/St) binary monomers system grafting onto SBS was investigated. Effects of the comonomer composition, concentration and irradiation dose were studied. The graft copolymer was characterized by Fourier-transform infrared, thermogravimetric analysis and differential scanning calorimetry. The results showed that binary graft could increased the grafting yield of MAH.  
        关键词：Styrene-Butadiene-Styrene block copolymer;Maleic anhydride;Styrene;Radiation graft   
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        发布时间：2023-03-30
      • ZHANG Jianghong,KONG Zhaolu,HAO Furong,SHEN Zhifen,JI Huajun,TONG Gaosun,HU Zhouhan,JIN Yizun
        Vol. 24, Issue 5, Pages: 298-302(2006)
        摘要：The object of this work is to study the radiation sensitizing effect and cytotoxicity to HepG2 cells of a newtapy bioreduction activity-5-(aziridin-1-yl)-3-hydroxymethyl-1-methylindole-4,7-dione(629) in vitro. Cytotoxicity of 629 or MMC in vitro were evaluated in HepG2 cells or hepatocyte by MMT method under anaerobic and aerobic, in vitro radiosensitizing ability was estimated using Cells Cloning Technology. The results suggested that the cytotoxicity of 629 to HepG2 cells has significant enhanced (p<0.05) than MMC, and no significant cytotoxicity to hepatocyte; in addition, 629 has radiosensitizing effect in vitro on HepG2 cells and the SER value ranged from 1.17 to1.92, it is showed that 629 have powerful radiosensitizing effect than MMC. The results indicated that 629 has radiosensitizing characteristic with high efficiency and low toxicity, and it is promising for clinic applications.  
        关键词：Bioreduction activity;Cytotoxocity;Radiosensitizing   
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        发布时间：2023-03-30
      • GAO Linfeng,WANG Hongfu
        Vol. 24, Issue 5, Pages: 303-307(2006)
        摘要：A study was done on cellular molecule mechanisms of abnormality of bone metabolism induced by 15Gy γ-ray exposure to rat kidneys. Three months after the kidney irradiation, the rats were sacrificed for analyzing changes in bone pathological morphous and expressions of related genes and proteins. In the irradiated group, TV/BV, Tb.Th, Tb.N decreased by 13.2%, 18.3%(p<0.05) and 20.1%(p<0.05), respectively, Tb.Sp increased by 34.8% (p<0.05), ES/BS increased by 20.2%(p<0.05). The ratio of RANKL/OPG mRNA expression increased by 52.2% (p<0.05). The expressions of mRNA and proteins of TGF-β, IGF-I, and OPN in the bone increased significantly. In conclusion, the 15Gy γ-ray irradiation of rat kidneys could result in significant abnormality of bone metabolism. Mechanisms of abnormality of bone metabolism induced by kidney exposure to γ-rays could be impairment of alpha-hydroxylase in the kidney, which leads to insufficient of active Vit-D and increased serum PTH, worsened imbalance of the ratio of RANKL/OPG, and significant increased TGF-β, IGF-I and OPN in osteoblasts.  
        关键词：Ionizing radiation;Kidney;Bone metabolism;Mechanism   
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        发布时间：2023-03-30
      • CHEN Liang,JIANG Shiping,WAN Libiao,MA Xiaodong,LI Meifang
        Vol. 24, Issue 5, Pages: 308-312(2006)
        摘要：The irradiation effect on Aspergillus oryzae spores was studied by 0.54keV X-rays (about the K shell absorption edge of oxygen) from the synchrotron facility at NSRL. A high production mutant for kojic acid was obtained from the spores irradiated by soft X-rays, which accumulated 27.79g kojic acid per L in 500mL shake-flask fermentation for 10 days using glucose as carbon source, and has increased about 56% of production than that of the original (17.81g/L). Also the fermentation conditions were studied with different carbon sources and nitrogen sources. The results showed that the mutant induced by the X-rays of synchrotron radiation would be of potential for high kojic acid production.  
        关键词：Aspergillus oryzae;Synchrotron radiation;Soft X-rays;Kojic acid   
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        发布时间：2023-03-30
      • WANG Yanling,ZHANG Hong,DUAN Xin,LIU Bing,ZHOU Qingming,LI Xiaoda,HAO Jifang,LIU Hui,ZHAO Weiping
        Vol. 24, Issue 5, Pages: 313-316(2006)
        摘要：To investigate the effect of 12C6+ ions radiation on the cell cycle and the expression of P53, MDM2 and P21 of SMMC-7721 cells. SMMC-7721 cells were irradiated with 12C6+ ions with the doses of 0Gy, 1.0Gy, 2.0Gy, 4.0Gy or 6.0Gy, then dose-survival curve of SMMC-7721 cells was figured by colony-forming assay. At 24h after irradiation cell cycle was analyzed by FACS and the expressions of P53, MDM2 and P21 were detected by Western-blot Assay. Results showed that the percentage of survival SMMC-7721 cells decreased with irradiation doses. The percentage of cells in G0/G1 phase increased after 1.0Gy, 4.0Gy, 6.0Gy 12C6+ ions irradiation compared with that of the control group. However, 2.0Gy 12C6+ ions irradiation increased the percentage of cells in G2/M phase. Compared to control, there were no changes in the expression of 57kD MDM2 in irradiated groups, but the expression levels of 76kD MDM2, P53 and P21 increased with irradiation doses. Therefore, the different doses of 12C6+ ions irradiation can activate different cell cycle checkpoints. The increased percentages of cells in G0/G1 phase were associated with the high expression levels of P53, P21 and 76kD MDM2 proteins.  
        关键词：12C6+ ions radiation;SMMC-7721 cells;Cell cycle;P53;MDM2;p21   
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        发布时间：2023-03-30
      • DING Jiansong,NIE Jihua,TONG Jian
        Vol. 24, Issue 5, Pages: 317-320(2006)
        摘要：Twenty-eight male wistar rats were randomly divided into seven groups, i.e. the radon groups (3), the propolis+radon groups (3) and the control (1). The propolis+radon groups were fed intragastrically with propolis 0.2g/kg, before exposing them, together with the radon groups, to radon and its peogeny with the cumulative dose up to 30, 67 and 111 working level month(WLM), respectively. The levels of SOD (superoxide dismutase) and MDA (Malonic dialdehyde) in blood and lung tissue were determined. The SOD level of in blood and lung tissues of the radon groups decreased significantly and the MDA level increased. The MDA level in lung tissue of the 30 WLM propolis+radon group was significantly higher than the 30 WLM radon group. The SOD level in lung tissue of the 67 WLM propolis+radon group was significantly higher, but the MDA level was significantly lower, than the 67 WLM radon group. Both the SOD and MDA levels in blood and lung tissue of the 111 WLM propolis+radon group were significantly higher than the 111 WLM radon group. In conclusion, the inhallation of radon and its progeny can lead to persistent disturbance of the redox state in rats. Propolis show some protective effects on the redox damage under the experimental conditions.  
        关键词：Radon and its progeny;Propolis;Superoxide dismutase;Malonic dialdehyde   
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        发布时间：2023-03-30

        研究论文

      • WANG Weiwei,CHANG Zhenqi,WANG Mozhen,ZHANG Zhicheng,LV Pin
        Vol. 24, Issue 5, Pages: 262-270(2006)
        摘要：Acrylic rubbers (ACM) carboxylated by acrylic acid or itaconic acid were prepared by 60Co γ-ray or chemical-initiator (K2S2O8) induced emulsion copolymerization. The polymers were characterized by Fourier transform infrared spectroscopy (FT-IR). Acid value, molecular weight and polydispersity index (PDI) of the polymers were determined by non-aqueous titration method and gel permeation chromatography (GPC), respectively. Vulcanization and mechanical properties of the filled ACM were studied by rheometric measurement, gel fraction analysis, mechanical property tests and dynamic mechanical thermal analysis (DMTA). The results show that the ACMs prepared by γ-ray irradiation have lower acid value, higher molecular weight and narrower PDI than chemically prepared ACMs of the same composition. The itaconic acid carboxylated ACM has better cure characteristics and mechanical properties than the acrylic acid carboxylated ACM. The itaconic acid carboxylated ACM prepared by γ-ray irradiation has higher gel fraction and better cure characteristics as well as mechanical properties than that prepared by chemical method.  
        关键词：γ-ray;Carboxylated acrylic rubber;Crosslink;Mechanical properties   
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        发布时间：2023-03-30
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