最新刊期
卷 8 ， 期 1 ， 1990
- 摘要：Small intestinal epithelium and testis are radiation sensitive organize. Microscopic structure and ultrastructure of small intestine and testis suffer serious damages after 7.5 Gy of 60Co γ-rays irradiation. However, bacterial superoxide dismutase displays obvious effects of radio-protectant on irradiated mice.关键词：Bacterial superoxide dismutase;Small intestine;Testis;Effect of radio-protectant
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The kinetics of 60Co-Gamma rays initiated inverse emulsion polymerization of acrylamide solution in kerosene with SPAN 80 as emulsifier has been studied dilatometrically. The following expressions have been determined for the conditions investigated: Rp∝I0.6[Am]1.0[SPAN 80]0.3, Mv∝I-0.1[Am]0.2[SPAN 80]-0.2. The overall activation energy for the rate of polymerization is 20.9 kJ/mol.The shapes of the conversion-time curves are effected by the stirring rate of emulsification. The diameters of most of the particles of monomer emulsions and polymer latexes are estimated to be about 2 micrometers by optical microscope.Based on the foregoing results, a monomer-droplet-nucleation mechanism is proposed for the systems studied.关键词：Acrylamide;Inverse emulsion polymerization;Radiation-induced polymerization
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：In this paper, the gamma-radiation effect on random 1,2-polybutadiene was studied by measureing sol fraction, double bonds conversion (by IR) etc. The network formation of irradiated unsaturated polymer was analysed and discussed theoretically. For the random chain reaction of irradiation 1,2-PB the relation between sol fraction S and radiation dose R/or crosslinking index γ/ can be expressed as follows:and from this, some information on crosslinking of irradiated unsaturated polymer system can be obtained.For the random 1,2-PB with high 1,2-unit contet, both intermolecular crosslinking and intramolecular cyclization take place simultaneously during irradiation, and cyclization reaction exceeds crosslinking formation G(cy)>G(c. 1). The effect of molecular weight of irradiated sample on radiation crosslinking was also discussed.关键词：Random 1;2-PB;The relation between S and R;The relation S and γ;Radiation crosslinking;Cyclization
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：T and B lymphocytes in human periphery blood were seperated by rosetting procedure. After lymphocytes were labelled with T4+ McAB, T4+ and non-T4+ lymphocytes were isolated by cell affinity chromatography method. When parts of T, B. T4+ and non-T4+ cells were exposed to 10 Gy 60Co γ-rays, the function of pokeweed mitogen (PWM) and 60Coγ-rays irradiation effect on lymphocytes were investigated by technique of 3H-TdR incorporation.The results showed that PWM can induce both T and B lymphocytes but B lymphocytes were more sensitive to PWM. The response of B lymphocytes to PWM was the same as that of non-T4+ cells, the response of T4+ cells to PWM was the lowest. DNA synthesis of both T and T4+ lymphocytes were synergistic to B lymphocytes. The synergistic effect in T and B lymphocytes was more strong than that in T4+ and B lymphocytes. When T and T4+ or B lymphocytes were irradiated by 10 Gy 60Co γ-rays, the synergistic effect disappeared. Neither synergistic nor suppressive effect was found between non-T4+ and B lymphocytes. When T4+, B and non-T4+ lymphocytes had been exposed to 10 Gy irradiation, the percentage suppression of 3H-TdR incorpora tion between B and non-T4+ lymphocytes had no significant difference but was higher than that in T4+ lymphocytes.关键词：Pokeweed mitogen (PWM);Monoclonal antibody (McAb);Lymphocyte subpopulation;Radiosensitivity
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：After I. V 85Sr, the whole body 85Sr-retentions in rats were fit to two compartment exponential equations. The equation parameters showed a sigificantly difference between the young group and both the adult and old groups (p<0.01), but there is no significant difference seen between the latter two groups. The biological half life(Tb2) for 85Sr in the slow compartment decreased in regular order from the young to the old groups. In the bone 85Sr-retention equations Tb2 of the slow compartment for 85Sr in the young group was sigificantly lower than the adult and old groups. The doses of the whole body and red-marrow for young rats were 4.2 times as much as those of adult rats, and 6.2 and 5.9 times as much as those old rats. The dose-cumulative speeds was most quick in the young groups and similar in the adult and the old.关键词：85Sr;Retention distribution;Internal dose;Age difference
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The principal of using pulse radiolysis technique to study the gas phase reactions of OH radicals with unsaturated hydrocarbons is described brifly in this paper. The temperature dependence of the rate constants of OH radicals with acetylene, ethylene, vinylchloride, propylene, 1-butene, allene and 1,3-butadiene is reported. Short discussion was given to the reaction mechanism.关键词：OH radicals;Pulse radiolysis;Arrhenius activition energy;Kinetic isotope effect;Reaction mechanism
- 1
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：In the present paper, Mixed radioiodines were injected intraperitaneously into rats with dose of 148×104, 74×104, 37×104 Bq and null respectively in 4 groups to observe their carcinogenic effects.The highest incidence of thyroid tumours in male rats treated with 74×104 Bq of radioiodines was 62.5% and the next was 54.6% in which treated with 37×104 Bq.The highest incidence of tumours in female rats treated with 37×104 Bq of radioiodines was 57.1%. The majority of tumours was derived from thyroid and the next from mammary gland.The thyroid tumours in both male and female rats were all originated from follicular epithelial of para-epithelial cells.The main type of benign tumours was polymorphofollicular adenoma and the malignant one medullary carcinoma.The carcinogenesis of mixed radioiodines was stronger than that from any single radioiodine which was a component of them, appearing the ratio of malignant to benign tumours being increased from 0.0 or 0.6 in the rats treated with only I-125, I-131, or I-132 up to 10.0.关键词：Mixed radioiodines;Thyroid;Adenomas;Carcinomas;Rats
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The storage of the solar energy by the isomerization of molecular is a new developing direction. The dynamic NMR (DNMR) is a effective means to study the reaction of isomerization. With the help of the interprization of 1H NMR spectra, it can be recognized that in a p-aminoazobenzene molecular the four hydrogen atoms of the benzene with a amino constitute a typical AA'XX' spin system, which has four coupling constants. And the product of the photo-isomerization reaction exhibits another (AA'XX')* spin system.According to the integral ratio of the (AA'XX')* system to the (AA'XX') system, we measured the ratio of the the product to the reactant under the different UV irradiation time at 2537×10-10m and knew the whole dynamic course.From 1H NMR and 13C NMR spectra, the influence of photo-isomerization reaction on the chemical shifts of every group or atom of the molecular can be understood.关键词：DNMR;Photoisomerization;p-aminoazobenzene
- 1
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：Human lymphocytes were treated with varying radioactivities of 3H-TdR and 3H-UdR in vitro and using the fluorescence plus Giemsa (FPG) technique to estimate the effects of tritium on the cell cycle. The results indicated that two kinds of tritiated compounds delayed the cell cycle of the proliferating lumphocytes in culture. The effects of delaying cell cycle were markedly increased with increasing the radioactivities of tritium. According to the efficiency of delaying cell cycle, when the radioactivity/ml of the medium was as high as 3.7×104Bq/ml, two compounds could be arranged in decreasing order as follows: 3H-UdR> 3H-TdR. The amount of tritium incorporated into cells could be affected by BrdU in the medium. Absorbed doses were increased with increasing time of culture. From the absorbed doses it could be seen that the different extent of delaying cell cycle between the two tritiated compounds could be due to different amount of tritium incorporated into cells. The results demonstrated that the tritiated compounds could affect lymphocyte proliferating rate. The cell proliferating rate index and mitotic index were decreased with increasing the absorbed dose.关键词：Tritiated compounds;Human lymphocytes;Cell cycle;Proliferating rate indes
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：In this work radioactive paper chromatograph was used to separate γ-irradiated products of 2-14C labelled thymine in N2O saturated solution and the G value of thymine dimers was determined to be 2.6. The preparative paper chromatography was adoped to isolate the dimers preliminary and then a high performance liquid chromatography equiped with a radiocativity detector was applied to separate both the preliminary isolated dimers and untreated sample. For further structure characterization of dimers a capillary gas chromatography-mass spectrometry (GC-MS)was used and the mass spectra were taken from each GC separated product peak of γ-irradiated thymine in N2O saturated solution after trimethylsilylation by BSTFA. TMS derivatives of radiation induced dimers of thymine showed the molecular ion(M+) and a characteristic ion (M- CH3)+ at 718,703; 628,613; 538,523; 540,525; These peaks were assigned to the following structures from several kinds of radical combination, such asThe dehydration of this dimer derives a variety of crosslinked products:TMS derivativesAnother kind of crosslinking is关键词：Thymine;Radiation crosslinking;GC-MS;HPLC
- 0
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：Self-Controling-Temperatue Heater is a new product. Its characteristics are safety and saving power. It is extensively applied in keeping temperature of pipelines, valves, storage tanks and so on. With the help of JiLin City Wire Plant, We have successfully made two types self-controling-temperature heaters, stable state temperature 55℃ (FJ-A type) and 85℃ (FJ-B type). In this paper, the work principle, the construction, properties and manufacture method of self-controling-temperature heater are described.关键词：Self-controling-temperature heater;Radiation crosslinking;Memory effect
- 1
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The plasma polymerization of vinyltrimethylsilane (VTMS) was carried out in a capacitively coupled tubular reactor with external electrodes. The polymerization laws were concluded when plasma gases existed or not and Rotatable Center Composite (RCC) way was used to optimize experimental data. The structure of polymer was characterized with IR, X-ray and elemental analysis.关键词：Plasma polymerization;Vinyltrimethylsilane;RCC;IR;Character
- 0
- |
- 0
- |
- 0
发布时间：2024-11-05
- Technical support is provided by Beijing Founder electronics co., LTD 沪ICP备05005479号-1
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0