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101.
102.
Vidmantas A. Raisys Patrick N. Friel Patricia R. Graaff Kent E. Opheim Alan J. Wilensky 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1980,183(4)
A one-step method for extraction of diazepam, nordiazepam, and internal standard into toluene is followed by chromatographic separation and detection with either dual-wavelength high-performance liquid chromatography or electron-capture gas—liquid chromatography. Agreement between the two methods was excellent for diazepam (r = 0.99, n = 38) and good for nordiazepam (r = 0.96, n = 79) over a concentration range that included subtherapeutic, therapeutic, and toxic plasma levels. 相似文献
103.
Patrick De Wever 《Geobios》1981,14(1):5-15
Studies of skeleton elements of several jurassic species of Saitoum allow to compare them with Poulpus from Trias. The sub-family Poulpinae is introduced, caracterised by three cephalic arcs and the collar position of the cephalic structure. Among the jurassic forms, 4 species are newly described: S. corniculum, S. elegans, S. levium and S. trichylum. 相似文献
104.
Oxygen availability,redox and the distribution of some Turbellaria Schizorhynchidae and other forms 总被引:3,自引:3,他引:0
Patrick J. S. Boaden 《Hydrobiologia》1981,84(1):103-112
Records from a considerable number of meiofaunal samples are reexamined in relation to the depth within sediment distribution of various taxa especially Schizorhynchidae and the main turbellarian orders.Frequency and density records in samples with particular oxygen flow rates and redox potentials confirm that the ranges of Schizochilus, Proschizorhynchus and Neoschizorhynchus spp. within these factors may help account for congeneric occurrence within cores. However, statistical analysis of the records is seldom able to confirm apparent differences. There is, for example, a statistically significant difference in distribution in relation to redox potential between the red schizorhynchians Pseudoschizorhynchides ruber, Diascorhynchus rubrus and the red acoelan Paratomella rubra but not in relation to oxygen availability and depth within sediment. On one beach Gnathostomula aff. paradoxa was found at Eh and O2 availability values under which it must be assumed to be living anaerobically.Contingency and other analyses are extended to differences between higher taxa and the results discussed in relation to habitat evolution of the Turbellaria. The suggestion that structural complexity of turbellarians has increased with increased oxygenation of the environment is tentatively supported. 相似文献
105.
The effects of mine drainage and organic enrichment on benthos in the river nent system,Northern Pennines 总被引:3,自引:3,他引:0
Patrick D. Armitage 《Hydrobiologia》1980,74(2):119-128
A preliminary survey of the benthic fauna of sites on the Nent system affected by elevated zinc levels, acid water and organic enrichment is described. Data on faunal composition are presented for 17 sites. A clustering technique was applied to the taxa/site matrix to demonstrate the degree of association between sites varying in zinc concentration. Chandler biotic scores were found to be lowest at sites affected by high zinc levels and/or dense growths of the alga Stigeoclonium tenue. The role of elevated zinc levels and algal growth in determining the diversity and abundance of benthos is discussed. 相似文献
106.
107.
Effect of Estuarine Sediment pH and Oxidation-Reduction Potential on Microbial Hydrocarbon Degradation 总被引:14,自引:9,他引:5 下载免费PDF全文
Microbial mineralization rates of two petroleum hydrocarbons, as affected by pH and oxidation-reduction potential, were determined in a Barataria Bay, Louisiana, sediment using 14C-labeled hydrocarbons. Hydrocarbon mineralization rates were inferred from the activity of respired 14CO2. Sediment pH and oxidation-reduction potential were important factors in governing the population of hydrocarbon-degrading microorganisms in the sediment and subsequent mineralization rates. Highest mineralization rates occurred at pH 8.0, and the lowest occurred at pH 5.0. At all pH levels mineralization decreased with decreasing oxidation-reduction potential (i.e., increasing sediment anaerobiosis). Generally, mineralization rates for octadecane were greater than those for naphthalene. Aerobic microorganisms in the oxidized sediment were more capable of degrading hydrocarbons than anaerobic microorganisms in reduced sediment of the same pH. 相似文献
108.
Daniel Mansuy Patrick M. Dansette Françoise Pecquet Jean-Claude Chottard 《Biochemical and biophysical research communications》1980,96(1):433-439
A biphasic system containing an iron porphyrin, Fe (TPP) (C1)1 or [Fe(TPP)]2O, efficiently catalyzes the cumyl-or tertiobutyl-hydroperoxide-supported dealkylation of p-nitroanisole and 7-ethoxycoumarin to the corresponding phenol and formaldehyde. Stoichiometric amounts of iron porphyrin and hydroperoxide give a quantitative reaction. Catalytic amounts of iron porphyrin give reaction rates and yields which are proportional to substrate concentration. With increasing hydroperoxide concentrations, the rates level offto limit values and the yield rapidly decreases. The maximum rates obtained approach those of the reactions mediated by cytochrome P 450-dependent monooxygenases. 相似文献
109.
Pyrroline-5-carboxylic acid reductase from soybean leaves 总被引:1,自引:0,他引:1
Pyrroline-5-carboxylic acid reductase was purified 40-fold from soybean leaves (Glycine max L. var Corsoy). The enzyme was fairly unstable, had a broad pH optimum, and was inactivated by heat and acid; NADH and NADPH both served as cofactors. It had a higher activity with NADH (about 4 ×) compared to NADPH, but a lower Km for NADPH. NADP+ inhibited both the NADH- and NADPH-dependent activity. Sulfhydryl group blocking agents reduced the activity as did the carbonyl blocking agent, NH2OH. Thiazolidine-4-carboxylic acid and phosphate inhibited the enzyme and proline inhibited only at high concentrations. ATP, GTP, and CTP were all effective inhibitors of both the NADH- and NADPH-dependent activity. Phosphorylated nucleotide inhibition was reversed by Mg2+ ions. 相似文献
110.
Photoreduction of sulfur dioxide by spinach leaves and isolated spinach chloroplasts 总被引:3,自引:2,他引:1 下载免费PDF全文
Labeled sulfur dioxide was found to be extensively absorbed by spinach (Spinacea oleracea L.) leaves. Labeled sulfides detected in leaf blades following fumigations with sulfur dioxide in light indicated that photoreduction of sulfur dioxide had occurred. Measurable proportions of this labeled sulfur was localized within the chloroplast fraction. Suspensions of isolated chloroplasts supplied with labeled sulfur dioxide contained labeled sulfides following a 30-minute illumination period in water-cooled reaction vessels. With reference to recent studies of the chloroplast sulfur reduction pathway, probable points of entry for sulfur dioxide and the subsequent release of hydrogen sulfide are discussed. 相似文献