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911.
912.
微核技术在环境监测中的应用概况 总被引:7,自引:0,他引:7
本文根据近年来我国利用微核技术监测环境污染的研究,对微核技术的基本原理及其生物学意义进行了简要的概述;并介绍了两种常用的植物微核技术-紫露草四分体微核技术和蚕豆根尖细胞微核技术;对目前我国微核技术的发展状况及存在问题进行了初浅的探讨。 相似文献
913.
914.
DHDPS是赖氢酸合成通路中第一步的合成酶。将中国春小麦的DHDPS基因质粒移植入RDA8中,得到RDA8/pDB26菌株,本研究通过细胞培养、层析提纯和结晶条件的探索,给出了一个较好的技术路线,并为开展义衍射分析蛋白结构创造了条件,通过该研究,对中国春小麦DHDPS和野种大肠杆菌的DHDPS差异有了一定的了解,并且对细胞培养的MM介质处理,DEAE-Sepharose,Phenyl-Sepharose和MonoQ层析的方法给出具体实验条仲。酶活的检测和蛋白浓度测定都是采取高灵敏度的方法。结晶的SCreening条件对于二种DHDPS有很大的差异。对野种大肠杆茵的DHDPS,需要表面活性剂N-octyl-D-glucopyranoside,pH10.0~10.5,对于中国春小麦一DHDPS则未找到较好的表面活性剂,pH6.8~7.6。中国春小麦一DHDPS晶体培养条件在以往文献中未见报导。 相似文献
915.
Urban airborne particulate: genotoxicity evaluation of different size fractions by mutagenesis tests on microorganisms and comet assay 总被引:4,自引:0,他引:4
The genotoxic effects of different size fractions of airborne particulate (Total, PM10 and PM2.5), extracted with acetone or toluene, were evaluated by: the Ames plate test (TA98 and TA100 strains, w/o S9), gene conversion and reversion (w/o endogenous metabolic activation) in the Saccharomyces cerevisiae D7 strain, and the comet assay on human leukocytes. The data on human leukocytes confirm the sensitivity of the comet assay and its applicability to assess genotoxicity in environmental samples. The PM2.5 fraction of airborne particulate generally shows the highest concentration of DNA-damaging compounds. Genotoxic response, in all the test systems applied, is highly dependent on extraction solvent used. Acetone seems to extract compounds with more similar genotoxic responses in the three test systems used than toluene extracts. Toluene appears to extract air pollutants genotoxic on yeast and leukocytes but is mainly cytotoxic on Salmonella. 相似文献
916.
Pham Van Khang Xuan Truong Mai Hiep Hoang Phu Sy Danh Thuong Shen Sida 《毒物与环境化学》2020,102(1-4):124-131
AbstractIn this study, The essential oil of flowers, fruits, and leaves of Thevetia peruviana, which were collected in Vietnam, were being reported for the first time. The essential oil of flowers was extracted by different methods: n-hexane extraction, distillation water, and supercritical CO2 extraction. The compositions of essential oil of different parts of Thevetia peruviana were analyzed by GC-FID and GC/MS systems. Major chemical compositions of essential oil were identified as monoterpenes, sesquiterpenes, terpenoids, and sterol. The activities of total essential oil extracts of the Thevetia peruviana exhibit inhibitory activities against five cancer cell lines. 相似文献
917.
黄精多糖的抗单纯疱疹病毒作用 总被引:24,自引:0,他引:24
体外抗单纯疱疹病毒试验表明:黄精多糖对非洲绿猴肾细胞(Vero cell)的最大4无毒浓度为16mg/mL。在对Vero细胞无毒性的浓度下对单纯疱疹病毒1型(Stoker株)和2型(333株和Sav株)均有显著的抑制作用,对Stoker株的半抑制浓度(IC50)为3.95mg/mL,最小有效浓度(MIC)为1.0mg/mL;对333株的IC50为8.0mg/mL,MIC为8.0mg/mL;对Sav株的IC50为7.72mg/mL,MIC为4mg/mL。MTT染色的结果表明,黄精多糖能显著提高病毒感染的Vero细胞的活力,对细胞有保护作用。图1表4参11。 相似文献
918.
Himraj Dang 《Environmental management》1993,17(3):283-288
Deforestation and decline in agricultural productivity are major concerns over large parts of sub-Saharan Africa. One of the
principal causes for both these phenomena is the export of woodfuels from rural agroecosystems to urban markets. This process
is noteworthy because of the size of the trade. Wood fuels (fuelwood, charcoal, and agricultural residues) constitute the
most important source of energy in these countries, varying from 60% to 95% of total energy consumption. In terms of the environmental
impact of the fuelwood trade, solutions typically considered are the introduction of improved cookstoves, fuelwood plantations,
and fuel substitution by conventional fuels. This article examines the structure of the fuelwood problem, reviews the successes
and failures of past experiences, and focuses on the potential for fuel substitution as an option to reduce the urban demand
for fuelwood. 相似文献
919.
Ryunosuke Kikuchi 《Environment, Development and Sustainability》2005,6(4):453-471
It is considered that use of hydrogen as an energy source may contribute to environmental improvement and provide an alternative energy system. Moreover, it is anticipated that hydrogen will be in great demand in the near future for use in such vehicles as fuel cell-based cars. Research and development of a number of advanced methods of hydrogen production (OTEC, water photolysis using a semiconductor, a municipal waste gasification—smelting system, etc.) is currently under way.A comparison of different hydrogen-rich fuels in this paper shows that methane is advantageous for hydrogen production from the viewpoint of energy efficiency as measured by thermodynamic analysis. This paper therefore proposes combining existing technology for hydrogen production with an unconventional methane source in order to facilitate the realization of a hydrogen energy system: i.e., this paper proposes combining the process of steam reforming, which is commercialized worldwide, with use of untouched natural gas hydrate (NGH) resources. Gas hydrate deposits, which are distributed worldwide, hold great amounts of methane gas and have hardly been touched. This paper presents the economic parameters of NGH development and discusses the concept of devising useful applications of NGHs, with consideration given to (1) independence from current fossil fuels; (2) energy transport using the hydrate system; (3) CO2 sequestration — replacement of methane hydrate with CO2 hydrate in the submarine layer and (4) improvement of current steam reforming of methane by CO2 reuse and zeolite application. This paper thus proposes a new solution that will make a key contribution to the systematic development of a new sustainable energy structure.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
920.
W. Allen Hogge M.D. Carol Blank Linda B. Roochvarg Joan S. Hogge Eric A. Wulfsberg Leslie J. Raffel 《黑龙江环境通报》1994,14(8):725-727
The Gorlin (naevoid basal cell carcinoma) syndrome is an autosomal dominant disorder consisting principally of naevoid basal cell carcinomas, odontogenic keratocysts, skeletal abnormalities, and intracranial calcification. We report the prenatal detection of the Gorlin syndrome by ultrasonography in a fetus with macrocephaly and mild ventriculomegaly. 相似文献