最新刊期
期 4 ， 2001
- 摘要：A feasibility of applying electron beam radiation technology in viscose rayon industry was introduced in this paper. It was difficulty to control the oxidation degradation of cellulose molecule in aging process of viscose rayon industry. The advantages of electron beam radiation degradation of cellulose were also related. A feasibility of electron beam radiation technology instead of oxidation degradation of cellulose was discussed on technology,process,economy and environment protection. And the development of the investigation of electron beam technology sued in viscose rayon in abroad was introduced.关键词：Electron beam;Radiation;Viscose Rayon;Paper pulp
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发布时间：2023-04-07 - 摘要：Dibutyl—o—phthalate (DBP) was irradiated with γ ray sealed in air or nitrogen at ambient temperture. The radiolysis products were analyzed by means of GC, GC/MS and PGC/MS,etc. Serious radiation degradation of DBP was showed. Not only general products such as hydrogen, methane, carbon dioxide and ethylene etc were examined,but also hydroxy or carbonyl compounds such as water, formic acid,allyl acohol, butyl alcohol,butyl aldehyde and phthalic anhydride etc were detected,two novel products 3—methyl benzofran and 3—methyl—dihydro—benzofran were found also. Remarkable effects of oxygen in ambience on formation of products hydrogen and carbon dioxide, but little effect on methane, were observed. The content of these three gaseous products all increased with dose,there was basiclly a linear relationship between the concentration of methane and dose. The radical reaction mechanism of dibutyl—o—phthalate radiation degradation was discussed.关键词：Dibutyl—o—phthalate;γ irradiated;Radiation degradation;Radical reaction mechanism
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发布时间：2023-04-07 - 摘要：γ ray radiation degradation of Fluororubber F2311 could take place above 50kGy at the atmosphere of vacuum, nitrogen and air. The gas contents from radiation degradation were analyzed by GC—MS. In addition, they were dissolved in water and analyzed by ion selective electrode and atomic absorption spectrometry (AAS). The results were as follows : the yields of H2(except in the air)、HF、HCl and CO2 got rise with the dose raising; nitrogen had some inhibiting effect on radiation degradation of fluororubber F2311; the product of hydrogen was the most at the dose of 500kGy in air, and that would reduce with the dose. G value and the gross decomposition ratio of gas from F2311 after irradiation in three kinds of atmosphere were determined.关键词：Fluororubber F2311;γ ray;Radiation degradation
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发布时间：2023-04-07 - 摘要：In this paper, grafting reaction of acrylamide onto pre—irradiated polypropylene fibers in inert medium (N2) has been studied. The grafting degree has been determined as a function of radiation dose,monomer concentration, temperature and reaction time. The experimental results showed that the best condition of grafting reaction was 10% methanol/water solvent, temperature 70℃, and reaction time 3 h. The mechanism of grafting reaction was characterized with ESR.关键词：Pre—irradiation;Grafting reaction;Polypropylene fibers;Acrylamide
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发布时间：2023-04-07 - 摘要：γ Irradiated rutin and baicalin ethanol solutions saturated with air were eluted through alumina columns and the G values of hydrogen peroxide generated in the solutions were measured. Different results from former works were obtained and the reasons of the difference were discussed. A precise method was established as follows : hydrogen peroxide should be separated from flavonoids by passing the flavonoids ethanol solutions through alumina columns before the measurement and the amount of hydrogen peroxide generated from self—oxidation of the flavonoids should be deducted. Under a dose rate of 6.93Gy min-1, the G values of hydrogen peroxide in γ irradiated rutin and baicalin ethanol solutions saturated with air were determined to be 5.5±0.2 and 7.3±0.2, separately. After irradiation of rutin— and baicalin—O2—ethanol solutions, the G values of hydrogen peroxide were increased comparing with that of pure ethanol—O2 solution.关键词：Rutin;Baicalin;Hydrogen peroxide
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发布时间：2023-04-07 - 摘要：HPV—16 immortalized human bronchial epithelial cells (BEP2D) were irradiated by 60Co gamma rays. 2', 7'—dichlorofluorescein and ethidium bromide, fluorescent products of the membrane—permeable dyes 2', 7'—dichloroflurescin diacetate and hydroethine, respectively,were used to monitor the intracellular production of hydrogen peroxides (H2O2) and superoxide anions (O2•-) respectively, by flow cytometry. 8—hydroxydeoxygunosine (OH8dG), a production of oxidative DNA damage, was examined with HPLC—ECD from extracted DNA. The results showed that the ROS productions and DNA adduct OH8dG in 60Co gamma rays irradiated BEP2D cells increased remarkably,and revealed better dose—response correlation. Further analysis indicated the positive correlation between intracellular ROS and content of OH8dG induced by 60Co gamma rays. Therefore, the effects of radiation on cell were involved increase of intracellular ROS and its production of oxidative DNA damage.关键词：60Co gamma rays irradiation;BEP2D;ROS;Oxidative DNA damage;8—hydroxydeoxygunosine.
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发布时间：2023-04-07 - 摘要：Using flow cytometry (FCM), The changes in expressions of p16, CyclinD1 and CDK4 in the thymocytes of mice treated with different doses of whole—body irradiation or with a fixed dose and different post—irradiation intervals were analyzed. The results showed that the expression of p16 protein in mouse thymocytes began to increase significantly at 8h after 2Gy X irradiation, reached the peak level at 24h, kept a high level until 48h, and recovered at 72h. The CDK 4 protein expression decreased at 8h after 2Gy irradiation, reached the bottom level at 12h, and recovered at 48h. The expression of CyclinD1 protein showed a little reduction only after 2Gy irradiation. Overexpression of p16 depended on the doses of radiation (0.5—4Gy). The expression of p16 in 2Gy group was significantly increased in comparison with that in the sham—irradiated group (p<0.01). The reduction of CDK4 expression was significant in 2Gy group (p<0.01). CyclinD1 expression showed its decrease after 0.5—2Gy irradiation. These results suggested that p16/CyclinD1/CDK4/pRb pathway might play an important role in G1 arrest of thymocytes induced by ionizing radiation.关键词：Ionizing radiation;p16;CDK4;CyclinD1
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发布时间：2023-04-07 - 摘要：To study the effects of radioprotectant—E838 on irradiated mice. Irradiated mice were injected intraperitoneally with E838 before and after irradiation. Then, the survival rate and the average living days of dead animals were calculated Meanwhile the peripheral blood WBC, bone marrow nucleate cells,CFU—GM and CFU—S were analysed. When used before irradiation, E838 could significantly increase the suvival rate and the average survival days of dead animals, and reduce the damage of the hematopoietic system. The results show that E838 has a good preventing effect on radiation injury.关键词：E838;Radiation injury;Hemapoiecsis
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发布时间：2023-04-07 - 摘要：To observe the effects of LDR on the synthesis of IL—10 in splenocytes and the secretion of IL—12 by peritoneal macrophages. Northern blot and flow cytometry were adopted to detect the changes of IL—10 at mRNA and protein level, respectively. Northern blot and ELISA were used respectively to examine the changes of IL—12p35/p40 mRNA and IL—12p70 protein levels. In splenocytes IL—10 mRNA decreased significantly,while both IL—12 p35 and p40 subunits in macrophages increased after WBI with 75 mGy X rays. Meanwhile, IL—10 synthesis in splenocytes decreased beginning from 4h after exposure and remaining at low level up to 48h, and IL—12 secretion by macrophages was found to take an opposite direction. WBI with 75mGy X rays may suppress IL—10 both at the mRNA level and protein level and stimulate IL—12 expression simultaneously, and this would lead to a shift of the immune response in favour of TH1 differentiation.关键词：Low dose radiation;Radiation hormesis;T cell differentiation;TIL—10;IL—12
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发布时间：2023-04-07 - 摘要：The deproteinized DNA samples of melanoma cells (B16) were irradiated by 50MeV/u 12C6+- of different dose rates. And the inverse pulsed—field gel electrophoresis was employed to measure the distribution of DSB fragments. The results show that both of the percentages of DNA released from plug (PR) induced by 3Gy/min and 30Gy/min increase with the rising dose and approach a similar quasi—threshold. The yields of DSB induced with 3Gy/min are 0.40DSBs/(100Mbp.Gy) while those induced with 30Gy/min are not obtained. The cross section of DSB induction with 30Gy/min is 2. 14m2, which is more than three times of that with 3Gy/min. These show that the higher the dose rate is, the more efficiently DSBs are induced. There is a peak about 860kbp of DSB fragments induced with 3Gy/min, which does not exist in the samples treated with 30Gy/min. It is implied that the dose rate has influence on the distribution of DSB fragments.关键词：DNA double—strand break;Dose rate;Tumor cells
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发布时间：2023-04-07 - 摘要：The electrical conductivity of low density polyethylene (LDPE)/carbon black (CB)irradiated by γ ray was investigated at different temperature. The relationship between the PTC and NTC effects was investigated by using scanning electron microscopy (SEM). The radiation dose was shown to have remarkable effects on the positive temperature coefficient (PTC) and negative temperature coefficient(NTC) effects of the composites. An interesting phenomenon was founded that at 400 kGy the NTC effect was nearly eliminated and when the radiation dose raise, the NTC effect reappears. The explanation of this particular behavior was discussed.关键词：Carbon black;Electrical conductive composites;Radiation crosslinking;Positive temperature coefficient (PTC)
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发布时间：2023-04-07 - 摘要：The radiation stability of N—decanoylmorpholine used as novel extractant for U(VI) from aqueous nitric acid medium was studied for the first time. The effects of radiation dose、concentration of nitric acid and diluente on the distribution ratio of U (VI) were discussed. It was founded that DMPHL has better radiation stability compared with TBP and the extraction abilities of the radiolytic products for U(VI) were lowered than DMPHL.关键词：Irradiation;N—Decanoylmorpholine;Solvent extraction
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发布时间：2023-04-07 - 摘要：In order to detect the radiation sensitivity of tumor cells,the methods of single cell gel electrophoresis (SCGE) and 3H—TdR incorporation were applieded to determine effects of radiation on single strand breaks of DNA in K562、SMMC—772 and HOS8603 cell lines. The experimental results proved that the cell migration distance was prolonged,DNA syntheses was restricted and the 3H—TdR incorporation rate was decreased in the above—mentioned 3 tumor cells lines after irradiation by 60Co γ rays(1—20Gy).关键词：Single cell gel electrophoresis (SCGE);DNA damage;3H—TdR incorporation;SMMC—772;HOS8603
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发布时间：2023-04-07 -
INFLUENCES ON TIME COURSE OF APOPTOSIS OF HeLaS3 CELLS AFTER IRRADIATION WITH DIFFERENT DOSES X RAYS
摘要：Changes of time course in apoptosis of HeLaS3 cells following irradiation with different doses X rays were observed. The percentages of apoptotic cells were examined by both flow cytometry(FCM) and image cytometry (ICM) after the cells were stained by propidium iodine (PI) and Hoechst33342 (HO). It was founded that the percentages of apoptotic cells increased after irradiation with 0.5—4.0Gy X rays and the peak value emerged at the 12th hour after irradiation. In additon the values examined by both FCM and ICM were nearly same and the tendency was identical. So irradiation may induce apoptosis of HeLaS3 cell lines.关键词：Irradiation;Apoptosis;Flow cytometry;Image cytometry- 2
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发布时间：2023-04-07 - 摘要：In an attempt to elucidate some aspects of the radiobiological basis of targeted radiotherapy in oncology,the apoptosis occurred have been studied in Hela cell lines after exposing to different doses and dose—rate radiation of 32P and the relationship between apoptosis occurred and the capacity of cell proliferation,which might be of help to the understanding of targeted radiotherapy. Asynchronous Hela cells were exposed to β radiation from 32P absorbed in filter papers which were put closely under culture dishes of growing monolayer of Hela cells. The radiation response characteristics to different dose、dose—rate and radiation time were evaluated through cell—proliferation assessed by the colony—forming assay, cell cycle perturbation studied by flow cytometry and quantity analysis of apoptosis analyzed by flow cytometry and fluorescence microscopy. Morphological and flow cytometry analysis showed a delayed apoptosis. The programmed cell death approached a plateau between 48—72h post—irradiation. Electron and fluorescence microscopic studies showed the presence of morphologically apoptotic cells. Single dose radiation showed a higher apoptosis ratio than multiple low dose radiation, which didn't correlate with clonal—forming assay,suggesting apoptosis ratio at a near time point post—irradiation is not a convincing indicator of radiation efficacy in the current experimental setting.关键词：32P;Targeted radiotherapy;Radiobiological mechanism;HeLa cell lines;Apoptosis;Cell proliferation;Cell cycle
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发布时间：2023-04-07
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