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91.
The non-ionic detergent octyl glucoside solubilizes a substantial amount of Streptococcus faecalis membrane protein without loss of the monitored enzyme activities. A secondary detergent, dioctanoyl phosphatidylcholine, appears to increase the yield of solubilized material. In addition, the effect of ionic strength indicates that it may be possible to selectively extract groups of membrane proteins by their characteristic solubility at different ionic strengths.The solubilized membrane-associated enzymes, ATPase and NADH dehydrogenase enter polyacrylamide gels as distinct species. Electrophoretic studies suggest that there are two membrane-associated ATPases in the Streptococcus faecalis, one which dissociates from the membrane in the absence of Mg2+ ions and the other which remains particulate until solubilized by detergents.Octyl glucoside can be easily removed from a solution containing solubilized proteins and lipid by dialysis. 相似文献
92.
93.
Leon Brimer S.Brøgger Christensen Jerzy W. Jaroszewski Frederick Nartey 《Phytochemistry》1981,20(9):2221-2223
A new cyanogenic glucoside, isolated from pods of Acacia sieberiana var. woodii, was shown to be (2R)-2- (β-d-glucopyranosyloxy)-3-hydroxy-3-methylbutanenitrile by spectroscopic and chemical methods. The absolute configuration of this glucoside was correlated with that of proacacipetalin by oxymercuration of the latter, followed by borohydride reduction of the product. 相似文献
94.
Savitri D. Srivastava 《Phytochemistry》1981,20(10):2445
Two new flavonoid glycosides, naringenin 7-galactosyl(1 → 4)glucoside and dihydroquercetin 5- galactoside, have been characterized from stem tissue of Dillenia pentagyna. Rhamnetin 3-glucoside was also isolated. 相似文献
95.
Twelve flavonoids including one new sulfate were isolated from Neurolaena lobata, and six known flavonoids were obtained from N. macrocephala. The new compound isolated from N. lobata is 6-hydroxykaempferol 3-methyl ether 7-sulfate, and the known flavonoids are 6-hydroxykaempferol 3,7-di-dimethyl ether, 6-hydroxykaempferol, 3-methyl ether 7-glucoside, 6-hydroxykaempferol 7-glucoside, quercetagetin and its 7-glucoside, quercetagetin 3,6- and 3,7-dimethyl ethers, quercetagetin 3-methyl ether 7-glucoside and 7-sulfate, 6-hydroxyluteolin 3′-methyl ether and 6-hydroxyluteolin 7-glucoside. The known flavonoids identified from N. macrocephala are quercetagetin 3,6- and 3, 7-dimethyl ethers, quercetagetin 6-methyl ether 7-glucoside, quercetagetin 3,6-dimethyl ether 7-glucoside, quercetagetin 7-glucoside and quercetagetin 3-methyl ether 7-sulfate. 相似文献
96.
Young sorghum shoots have been shown to convert tyrosine, p-hydroxyphenylacetaldoxime and p-hydroxyphenylacetonitrile to dhurrin, the cyanogenic glucoside characteristic of this plant. Evidence for the in vivo formation of p-hydroxyphenylacetaldoxime but not p-hydroxyphenylacetonitrile from tyrosine has been obtained from a 'trapping experiment.' 相似文献
97.
Siegfried Huneck 《Phytochemistry》1973,12(10):2497-2500
From the lichen Lobodirina cerebriformis (Mont.) Follm. Roccellaceae) a new chromone glucoside lobodirin (I) has been isolated. The structure, 7-0-β-d-triacetylglucosyl-isoeugenitol, was established by hydrolysis to glucose isoeugenitol by synthesis of acetyllobodirin from α-acetobromoglucose and isoeugenitol with subsequent acetylation. 相似文献
98.
Endogenous pools of presumptive gibberellin (GA) glucosyl conjugates of Phaseolus coccineus were metabolically labelled by feeding of [3H]GA1 to immature fruits. The [3H]GA1 glucoside fraction was isolated and the main constituent tentatively identified by enzymic hydrolysis, ion exchange chromatography and elution volume on HPLC-RC as GA1-3-0--D-glucopyranoside. 相似文献
99.
In addition to cardiospermin-5-(4-hydroxy)benzoate previously isolated from Sorbaria arborea, two further leucine-derived cyanogenic glucosides hav 相似文献
100.
Emmanuelle S. Briolat Mika Zagrobelny Carl E. Olsen Jonathan D. Blount Martin Stevens 《Journal of evolutionary biology》2019,32(1):31-48
Many defended species use conspicuous visual warning signals to deter potential predators from attacking. Traditional theory holds that these signals should converge on similar forms, yet variation in visual traits and the levels of defensive chemicals is common, both within and between species. It is currently unclear how the strength of signals and potency of defences might be related: conflicting theories suggest that aposematic signals should be quantitatively honest, or, in contrast, that investment in one component should be prioritized over the other, while empirical tests have yielded contrasting results. Here, we advance this debate by examining the relationship between defensive chemicals and signal properties in a family of aposematic Lepidoptera, accounting for phylogenetic relationships and quantifying coloration from the perspective of relevant predators. We test for correlations between toxin levels and measures of wing colour across 14 species of day‐flying burnet and forester moths (Lepidoptera: Zygaenidae), protected by highly aversive cyanogenic glucosides, and find no clear evidence of quantitative signal honesty. Significant relationships between toxin levels and coloration vary between sexes and sampling years, and several trends run contrary to expectations for signal honesty. Although toxin concentration is positively correlated with increasing luminance contrast in forewing pattern in 1 year, higher toxin levels are also associated with paler and less chromatically salient markings, at least in females, in another year. Our study also serves to highlight important factors, including sex‐specific trends and seasonal variation, that should be accounted for in future work on signal honesty in aposematic species. 相似文献