全文获取类型
收费全文 | 158篇 |
免费 | 4篇 |
国内免费 | 9篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 13篇 |
2012年 | 6篇 |
2011年 | 6篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 8篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 1篇 |
1974年 | 3篇 |
排序方式: 共有171条查询结果,搜索用时 109 毫秒
31.
Metabolism of polychlorinated biphenyls by Solanum nigrum hairy root clone SNC-9O and analysis of transformation products 总被引:1,自引:0,他引:1
Kučerová Petra Macková Martina Chromá Ludmila Burkhard Jiri Tríska Jan Demnerová Katerina Macek Tomáš 《Plant and Soil》2000,225(1-2):109-115
The study investigates aspects of PCB metabolism by a hairy root culture of Solanum nigrum L. (clone SNC-9O) in vitro. Standard conditions were established for efficient, up to 72% PCB conversion (22 individual PCB congeners examined in commercial
mixture Delor 103, 5 g fresh biomass in 100 ml media shaken with 5 mg PCB for 14 days). The conversion products formed from
three monochlorobiphenyls were monohydroxychlorobiphenyls and dihydroxychlorobiphenyls, while six dichlorobiphenyls yielded
different monohydroxydichlorobiphenyls. Efficiency of the transformation of individual PCB congeners was evaluated together
with phytotoxic effect on the clone SNC-9O. Major metabolites of monochlorobiphenyls analysed after extraction from biomass
were hydroxylated at the position 4, and 4′, respectively.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
32.
As there are at least three types of bacteria involved in the aerobic mineralization of polychlorinated biphenyls (PCBs), this study was undertaken to determine what catabolic features are lacking in biphenyl-degraders and to determine if chlorobenzoate- and chloroacetate-utilizing bacteria are as indigenous to soil as biphenyl-degraders. Bacteria were tested for their ability to utilize chlorinated acids and to cometabolize Aroclor 1254 and dibenzo-p-dioxane (dioxin). The broad and variable substrate specificity of the biphenyl dioxygenase among strains was noted by the range of <1 to 53% cometabolism of total PCB congeners and by the oxidation of dioxin, which was not a growth substrate. Growth on chloroalkanoic acids was more frequent with 2-chloropropionate (87% of all strains), 3-chloropropionate (72%), 4-chlorobutyrate (66%), and less frequent (28%) withtrans-3-chlorocrotonate. However, only one strain,Pseudomonas fluorescens K3, could utilize chloroacetate. No biphenyl-utilizers grew on 2- or 4-chlorobenzoate, and only five strains grew on 3-chlorobenzoate. Acetate and benzoate-utilizers were found in all three soils tested at levels near 106/g, whereas chloroacetate- or chlorobenzoate-utilizers were not detected. The inability of biphenyl-degraders to dehalogenate the products of PCB cometabolism is clearly unrelated to metabolism of saturated chloroaliphatic acids, with the notable exception of chloroacetate, since most strains grew on them. Thus, the inability to utilize chloroacetate, a central intermediate in the meta fission pathway, may be relevant to the incomplete catabolism of PCBs by biphenyl-utilizers. 相似文献
33.
B N Aronstein J R Paterek R L Kelley L E Rice 《Journal of industrial microbiology & biotechnology》1995,15(1):55-59
A series of experiments was conducted to examine the effects of chemical pretreatment on biodegradation of14C-labeled PCB congeners in aqueous systems. Fenton's reagent was used to generate hydroxyl radicals (OH) which were successful in partially oxidizing/transforming otherwise recalcitrant molecules of tetrachlorinated PCB, but had little or no impact on the biodegradation of a monochlorinated congener. Application of Fenton's reagent (1% H2O2, 1 mM FeSO4) followed by inoculation with pure culturesPseudomonas sp, strain LB 400 andAlcaligenes eutrophus, strain H850 resulted in the removal of approximately 38% of 2-chlorobiphenyl and 51% of 2,2, 4,4-tetrachlorobiphenyl in the form of14CO2. Comparison of the rate and extent of biodegradation of 2,2, 4,4-tetrachlorobiphenyl after the application of Fenton's reagent with the dynamic and final level of radioactivity in the aqueous phase of experimental system suggests two possible means of microbial utilization of tetrachlorinated PCB congener altered by chemical oxidation: (a) consumption of the partially oxidized chemical dissolved in the aqueous phase, and (b) direct microbial attack on the transformed compound, which may still be adhered to the solid surface. 相似文献
34.
Ying Teng Xiufen Li Ting Chen Manyun Zhang Xiaomi Wang Zhengao Li 《International journal of phytoremediation》2016,18(2):141-149
A bacterial strain ZY1 capable of utilizing PCBs as its carbon source was isolated from the root nodules of Chinese milk vetch (Astragalus sinicus L.). The strain was identified as Mesorhizobium sp. according to its physiological-biochemical properties and the analysis of its 16S rRNA gene sequence. When the initial OD600 was 0.15, 62.7% of 15 mg L?1 3,3′,4,4′-TCB in a liquid culture was degraded by Mesorhizobium sp. ZY1 within 10 days. Mesorhizobium sp. ZY1 also greatly increased the biotransformation of soil PCBs. Pot experiments indicated that the soil PCB concentrations of a single incubation of strain ZY1 (R) and a single planting of A. sinicus (P) decreased by 20.5% and 23.0%, respectively, and the concentration of PCBs in soil treated with A. sinicus and strain ZY1 decreased by 53.1%. We also observed that A. sinicus-Mesorhizobium sp. ZY1 treatment (PR) improved plant biomass and the concentration of PCBs in plants compared with a single A. sinicus planting treatment (P). The results suggest that the synergistic association between A. sinicus and PCBs-degrading Mesorhizobium sp. ZY1 can stimulate the phytoextraction of PCBs and the rhizosphere microflora to degrade PCBs, and might be a promising bioremediation strategy for PCB-contaminated soil. 相似文献
35.
C. Ramel 《Mutation research》1975,33(1):79-86
A survey is given of Swedish legislation for control of chemicals in the environment. Although no direct legal requirements for mutagenicity testing of chemicals exist at present in Sweden, such requirements can be enforced within the existing laws.Testing and research in chemical mutagenicity are especially performed at the Environmental Toxicology Unit of the Wallenberg laboratory, University of Stockholm. An outline is given of the organization of the unit, which is based on an interdisciplinary cooperation, among divisions of organic and analytical chemistry, cellular toxicology, and genetics. As examples of projects under joint investigation results on polychlorinated biphenyl (PCB) and on vinyl chloride are briefly described. 相似文献
36.
Hepatic DNA, RNA, protein and p-nitroanisole O-demethylase, aniline hydroxylase, nonspecific carboxylesterase, bromosulphophthalein-glutathione (BSP-GSH) conjugating enzyme and p-nitrophenol UDPglucuronyl transferase activities were measured in young Wistar male rats which had received intraperitoneal injections (50 mg/kg) of biphenyl and Aroclors 1016, 1221, 1232, 1242, 1248, 1254 and 1260, dissolved in peanut oil, for 3 consecutive days and assayed 96 h after the last injection. Biphenyl and all the Aroclors caused the same degree of enhancement of BSP-GSH conjugating enzyme. Decreased DNA content, increased RNA and protein content and the other enzymatic activities were related to the percent weight of chlorine and the chlorobiphenyl composition of the Aroclors. More marked effects were observed with the highly chlorinated Aroclor 1248, 1254, and 1260 mixtures which contained predominantly tetra-, penta-, hexa-, and higher-chlorinated biphenyls. 相似文献
37.
The 7-methylbenzo[a]pyrene (7-MBaP) was incubated with liver microsomes of rats pretreated with polychlorinated biphenyls (Aroclor 1254) (PCBs). Metabolites of 7-MBaP were isolated by both reversed-phase and normal-phase high performance liquid chromatography (HPLC) and were characterized by nuclear magnetic resonance, UV-visible and mass spectral analyses. The predominant metabolite of 7-MBaP was found to be 3-hydroxy-7-methylbenzo[a]pyrene (3-hydroxy-7-MBaP). Other identified metabolites include 7-MBaP 4,5-, 7,8-, and 9,10-trans-dihydrodiols, 7-hydroxymethyl-BaP, 7-hydroxymethyl-BaP trans-9,10-dihydrodiol, 9-hydroxy-7-MBaP, 3-hydroxy-7-hydroxymethyl-BaP, 7-MBaP 1,6- and 3,6- quinones, and a hydroquinone which is also formed by further metabolism of the 3-hydroxy-7-MBaP. Comparative metabolic studies of 7-MBaP and BaP indicated that, relative to that of BaP, the methyl substituent of 7-MBaP slightly increases the formation of 3-hydroxy-7-MBaP and decreases the metabolism at other regions of the 7-MBaP molecule. The finding that a 7,8-dihydrodiol is a metabolite indicates that, like BaP, 7-MBaP may also be activated to the potentially reactive 7,8-dihydrodiol 9,10-epoxides although their formations are significantly reduced. 相似文献
38.
39.
Transformation of Pseudomonas putida with chromosomal DNA 总被引:3,自引:0,他引:3
J R Mylroie D A Friello A M Chakrabarty 《Biochemical and biophysical research communications》1978,82(1):281-288
The deiodination of [125I]-4-iodobiphenyl, [125I]-4-iodonitrobenzene and [125I]-4-iodoaniline was investigated. No deiodination was detected in rat thyroid homogenates. However, at least three biodeiodination mechanisms were indicated for substrates in rat liver subcellar fractions. Microsomal dehalogenation occurred to a minor extent with increased dehalogenation taking place in the cytosol fraction. The cytosol deiodination was extensive for 4-iodonitrobenzene and was mediated by glutathione. A second cytosol deiodination mechanism, not mediated by glutathione, was evident when 4-iodobiphenyl was the substrate. This soluble enzyme system could be enhanced by Arochlor 1254 or 4-iodobiphenyl pretreatment. 相似文献
40.
Tony R. Walker Rob Willis Tim Gray Bradley MacLean Scott Mcmillan Melissa Leroy 《Soil & Sediment Contamination》2015,24(5):471-493
Contamination within sediments of Sydney Harbour (once a major industrial port) were evaluated using a multiple lines-of-evidence (LOE) ecological risk assessment (ERA) approach prior to divestiture of the harbor. The multiple LOE approach included: (1) measurement of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), metals, metalloids, petroleum hydrocarbons(PHCs), and total organic carbon (TOC) concentrations in surface sediments from multiple Sydney Harbour locations; (2) identification and application of sediment quality guidelines (SQGs) from various jurisdictions; (3) comparisons of harbor sediment chemistry against background/reference sediment chemistry; (4) determining number and frequency of exceedances over SQGs; (5) calculating mean probable effect level-quotients (PEL-Qs); (6) PAH forensic source evaluation; (7) review of previous sediment chemistry and biota tissue data; and (8) characterizing benthic habitat at harbor stations. The ERA determined that current sediments exhibited mostly low probability of adverse effects. Furthermore, contaminated sediments exhibiting a high probability of adverse effects were localized to only a few stations within the harbor. Ongoing natural recovery of harbor sediments is likely responsible for attenuating contaminants that historically were higher than those measured in this study and were previously distributed over much wider areas of the harbor. Results suggest that legacy industrial activities and current urban sewage effluents are the major sources of contamination in Sydney Harbour sediments. 相似文献