最新刊期
卷 14 ， 期 3 ， 1996
- 摘要：In this paper, a new thermo-sensitive hydrogel that N-isopropyl -acrylamide (NIPAAm) was grafted onto ethylene-vinylacetate copolymer (EVA) by preirradiation grafting was obtained, and the effect of reaction condition on grafting reaction and thermo-sensive were discussed. The experimental results showed that the grafting reaction on EVA with NIPAAm has common characteristics of preirradiation grafting reaction. Compared with the poly-NIPAAm gel, the grafted EVA with NIPAAm behave the better mechanical strength and the more swift response to the change of temperature.关键词：Irradiation grafting;Biological medical material;Thermo-sensitive;Ethylene-vinylacetate copolymers (EVA)
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The attenuation and scattering coefficients of gamma-rays of different energies in two sedimentary and two igneous natural rocks: siltstone, conglomerate, andesite and felsite respectively, and also in compressed powdered samples of the same four rocks, were studied. The effects of particle size （grain diameter d mm） and sample density, ρ, with radiation energy （E） ranging from 0.36 to 1.33 MeV, were investigated. The results showed an inverse proportionality between the linear attenuation coefficient µ and both d and E, also we found that µ has a direct proportionality with the sample density, ρ. The side scattering coefficient, ϕ, is directly proportional to both d and E, but at the same time ϕ has an inverse proportionality with the sample density ρ.关键词：Sedimentary rock;Igneous rock;Attenuation coefficient;Side scattering coefficient
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The transient progress of cationic polymerization of divinyl ether DVE-3 (D) and iron onium salt IRGACURE 261(1) was studied by 10 Mev EB pulse radiolysis. In the transient spectra, a clear updown peak in 380 nm (0.1 ~80µs)appeared in divinyl ether-iron onium salt dichloromethane solution but not appeared in diacrylic ester-iron onium salt dichloromethane solution. Furthermor, the updown peak at 380 nm was getting small as the divinyl ether-iron onium salt solution saturated in nitrogen, air, oxygen respectively. It might suggested that divinyl ether containing rich electron bond may contact with iron onium salt to form charge transfer complex and then decomposed to form cation ions to initiate polymerization as radiatied, also, that oxygen can contact with cation ions to form cation hyperoxide to initiate polymerization.关键词：EB pulse radiolysis;Divinyl ether;Cationic polymerization
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The gel fractions of irradiated polyvinyl alcohol (PVA) aqueous solution have been measured. The gel fraction increases with absorbed dose. At same dose, the gel fraction increases with PVA concentration and gradually reaches a staturation state. Cyanuric acid, N,N'-methylene-bis-acrylamide and hexamethylene tetramine have sensitization effect for radiation crosslinking of PVA. The gelation dose decreased at that condition. The relationships between water content of PVA hydrogel with dose and swelling time have been measured.关键词：Polyvinyl alcohol;γ-irradiation;Hydrogel;Additive;Gelation dose;Gel fraction
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：Post radiation effects on polyamide 1010 were studied by DSC and the determination of gel fraction. The transition and relaxation of macromolecules in the crystalline phase imposed on by post radiation effects of polyamide 1010 were also investigated. Futhermore, the influence of the fold surface on post radiation effects was focused on. The results showed that the trapped radicals in the fold surface attributed to postradiation effects. The more the amount of the fold surface of the lamellae is, themore profound post radiation effects on polyamide 1010 show.关键词：Polyamide 1010;Post radiation effects;Gel fraction;Fold surface of the lamellae;Trapped radicals
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：With HPLC, it was found that there was few free base A molecule being released from the solid adenosine (AR) irradiated by 20 keV N+ ion beam, But with UV-spectra, it was known that the yield of base A increased in the the irradiated AR sample treated by 1 mol/L NaOH or pH0.5 H2SO4. and about 15%of the damaged AR molecules was able to produce base A. With heat treatment, the UV spectra of the alkaline solution and the acid solution of irradiated AR samples and the yield of A were obviously changed. Besides, the G value of the damaged AR molecules and the produced A molecules were calculated and it was found that the G values had a tendency of decreasing with increasing dose. In addition, The phenomenon of the yield of A increasing in alkaline and acid solutions was respectively explained by OH-attach mechanism and oxidization mechanism.关键词：ion beam;Adenosine;Irradiation damage
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The photochemical erossilinking of epoxy acrylates directly initiated by 2-alkyl anthraquinones (AQ) in the absence of activators was studied in this paper. The changes of double bond content, photocrosslinking density, gel conversion and hardness of cured film in the ptotocuring process were monitored by photospectrometry and gravimetry. The experimental results show that the 2-alkyl AQ exhibits a high initiation efficiency which is comparable with dimethoxy-2-phenyl acetophenone and thioxanthone photoinitiators. Moreover AQ is very cheap and its photocuring can be operated in the air condition. The effects of initiator concentration, proportion of components and initiation efficiencies for different kinds of epoxy acrylates were also discussed关键词：2-alkyl anthraquinones;Epoxy acrylate;UV photocrosslinking
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The stable chromosome aberrations of medical diagnostic X-ray workers were analyzed using G-banding and evaluated their accumulative doses. The results showed that the frequencies of reciprocal translocation, stable aberration and total aberration among the 4417 metaphase spread from 44 cases of medical diagnostic X-ray workers were distinctly higher than control values (P<0.05~0.005). The stable aberration predominated strikingly in total aberration and reciprocal translocation was 57% in the stable aberrations. The medical diagnostic X-ray workers were divided into 3 groups according to calendar year of entry. The data showed that the frequencies of total aberration, stable aberration and reciprocal translocation incerased with working years, especially in two groups who started working before 1970, there are statistically significant differences between the calendar year of entry before 1660 and 1960~1969 in X-ray workers and control group. According to the equation recommended by straume, linear coefficient (α) in linear quadratic model recommended by Schmid and the transformation coefficient by Lucas. The accumulative doses calculated are 0.58, 0.37 and 0.07 Gy for calendar year of entry before 1960, 960~1969 and after 1970 in X-ray workers, respectively.关键词：Stable chromosome aberrations;Medical diagnostic X-ray workers;Biodosimetry
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The role of intracellar glutathione (GSH) in radiation protection has been noticed in recent years. In this study, we found that the level of intracellar glutathione and radiosensitization had a certain relationship. It was recognized that the higher GSH level, the lower radiosensitization. The GSH level in V 79-379 A, Y 79, SPC-A-1, SGC-7901 and So-Rb 50 cells were showed in this experiments by Tietze method. The GSH level which was depleted by BSO was assessed. The radiosensitization was determined by the standard colony formation assay IN VITRO. The results showed that SER (Sensitization Enhancement Ratio) for V 79-379 A cell was increased with GSH depletion. The SER for BSO 0.1, 0.5 and 1.0 mmol/L were 1.16, 1.34 and 1.50, respectively. Same results for Y 79 cells were also observed that the SER for BSO 0.01 and 0.05 mmol/L were 1.21 and 1.36 respedively. On the other hand, the exposure time of BSO also influenced GSH level and SER. These results suggested that the level of glutathione in cell and radiosensitization has a close relationship.关键词：Glutathione (GSH);Buthione sulfoximine (BSO);Radiosensization
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The purpose of this study was to evaluate the possibility in the inhibitory effects of thymosin on S180 tumor growth in mice. On the basis of the tumor responses the following results were found (1) No improved therapeutic effects were obseved when p. o. administration of thymosin was combined with γ-ray irradiation. (2) When it was combined with cyclophosphamide the enhancement of anti-tumor effects was obvious. (3) Comparing p. o. with i. p. administration of thymosin, the same effect of inhibitory tumor growth was observed. (4) When the thymosin at the dose of 1.25~5 mg/kg were administerd, the slow down in relative tumor growth rate and increas in tumor inhibition rate were observed, but there was no obvious linear relationship between drug dose and tumor inhibitory response.关键词：Thymosin;Oral;Administration;S180 sarcoma;Relative tumor growth rate;Tumor inhibition rate
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：Irradiation processing technique is a new processing technique after machining, heating and chemical methol, ets. several principal processing technique. At present, in China building and building has been completed electron accelerator for industry had 40 seats, total power had 1436 kW. products had 8 type and seteral ten kinds.关键词：Irradiation processing;Electron accelerator;Application
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The radiosensitivities cell lines were deferimed in two different pathologic types of nasopharyngeal carcinoma with chromosome assay. The radiosensitivity was lower for the cell line of high differentiated nasopharyngeal carcinoma than that of poorly differentiated one. This result might be some reference for radio-therapy.关键词：Nasopharyngeal carcinoma;Chromosome;Radiosensitivity
- 2
- |
- 0
- |
- 0
发布时间：2024-11-05 - 摘要：The effects of TSWCP on leukocyte conts, phagocytic functions of macrophages and lymphocyte micronuclei in irradiated mice were studied. The results showed that TSWCP could increase leukocyte counts, phagocytic and digestive function of macrophages, and decrease lymphocytes micronuclei in irradiated mice significantly.关键词：Trionyx sinesis wingmann crude proteoglycan (TSWCP);Leukoyte;Phagocytic function of macrophages;Lymphocyte micronuclei
- 2
- |
- 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