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1.
Elliott C. Kulakowski Joseph Maturo Stephen W. Schaffer 《Archives of biochemistry and biophysics》1981,210(1):204-209
Cardiac sarcolemma preparations of both pig and rat ventricles were found to possess two sets of taurine-binding components. The two proteins from pig heart were solubilized with the detergent Ammonyx-Lo. Characterization of these solubilized proteins revealed that both components are glycoproteins and retain the binding properties observed for the membrane isolate. However, the characterization also revealed several differences between the proteins including their binding specificities, their affinities for taurine, their binding isotherms, and their molecular sizes. Possible functions of these two taurine-binding proteins are discussed. 相似文献
2.
Yohimbine increases plasma insulin concentrations of dogs 总被引:1,自引:0,他引:1
W H Hsu D D Schaffer M H Pineda 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1987,184(3):345-349
Recent evidence suggests that catecholamines inhibit insulin release by stimulating alpha 2-adrenoreceptors in beta-cells of the pancreatic islets. In the present study, iv injections of 0.1 and 0.3 mg/kg of yohimbine, an alpha 2-adrenoreceptor antagonist, resulted in increased plasma insulin and decreased plasma glucose concentrations in the dog. The use of alpha 2-adrenoreceptor antagonists may be of value in non-insulin-dependent diabetic patients by counteracting the inhibitory influence of endogenous catecholamines. 相似文献
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4.
A firm, mobile, oblong mass was discovered as an incidental finding in the stomach of a chimpanzee (Pan troglodytes) during routine surgery. It was removed and determined to be a trichobezoar. 相似文献
5.
Staphylococcus aureus counts from swimming pool water were determined by the membrane filtration technique. Water samples were passed through a membrane filter and then put on Baird-Parker media. After incubation, the filters were transferred to nutrient agar, and incubated at 37 degrees C, for 3 h. After removal of the filters, the plates were incubated at 60 degrees C for 2 h. An overlay of toluidine blue agar was added and the plates reincubated for 4 h at 37 degrees C. The formation of thermonuclease correlated with the formation of coagulase, and the results indicated that Staphylococcus aureus could be present in swimming pool water without the presence of either coliform or faecal coliform bacteria. 相似文献
6.
The nodulation of adventitious roots growing from segments of bean hypocotyl tissue was used as a bioassay for the material present in coconut water which stimulated nodulation. The active material in coconut water is acidic, but it was not possible to extract it from an acid solution with organic solvents. A purification of approximately 70-fold (on a dry wt basis) was obtained using activated charcoal, but at least 10 different compounds were present in the active fractions. A purified fraction of coconut water, which is stimulatory to the growth of carrot root explants, was active in the nodulation assay at a concentration of 2 μg/ml. This represents a 4000-fold purification of the diffusible fraction of coconut water. The charcoal fractionation procedure can be applied to the active material present in extracts of bean leaves. 相似文献
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Overexpression of the herpes simplex virus type 1 immediate-early regulatory protein, ICP27, is responsible for the aberrant localization of ICP0 and mutant forms of ICP4 in ICP4 mutant virus-infected cells. 总被引:5,自引:5,他引:0 下载免费PDF全文
ICP0 and ICP4 are immediate-early regulatory proteins of herpes simplex virus type 1. Previous studies by Knipe and Smith demonstrated that these two proteins are characteristically observed in the nuclei of wild-type virus-infected cells but predominantly in the cytoplasms of cells infected with several ICP4 temperature-sensitive (ts) mutant viruses at the nonpermissive temperature (NPT) (D. M. Knipe and J. L. Smith, Mol. Cell. Biol. 6:2371-2381, 1986). Consistent with this observation, it has been shown previously that ICP0 is present predominantly in the cytoplasms of cells infected with an ICP4 null mutant virus (n12) at high multiplicities of infection and that the level of ICP27, a third viral regulatory protein, plays an important role in determining the intracellular localization of ICP0 (Z. Zhu, W. Cai, and P. A. Schaffer, J. Virol. 68:3027-3040, 1994). To address whether the cytoplasmic localization of ICP0 is a common feature of cells infected with all ICP4 mutant viruses or whether mutant ICP4 polypeptides, together with ICP27, determine the intracellular localization of ICP0, we used double-staining immunofluorescence tests to examine the intracellular staining patterns of ICP0 and ICP4 in cells infected with an extensive series of ICP4 mutant viruses. In these tests, compared with the localization pattern of ICP0 in wild-type virus-infected cells, more ICP0 was detected in the cytoplasms of cells infected with all ICP4 mutants tested at high multiplicities of infection. Each of the mutant forms of ICP4 exhibiting predominantly cytoplasmic staining contains both the nuclear localization signal and the previously mapped ICP27-responsive region (Z. Zhu and P. A. Schaffer, J. Virol. 69:49-59, 1995). No correlation between the intracellular staining patterns of ICP0 and mutant forms of ICP4 was demonstrated, suggesting that mutant ICP4 polypeptides per se are not responsible for retention of ICP0 in the cytoplasm. This observation was confirmed in studies of cells cotransfected with plasmids expressing ICP0 and mutant forms of ICP4, in which the staining pattern of ICP0 was not changed in the presence of mutant ICP4 proteins. Studies of cells infected at low multiplicities with a variety of ICP4 ts mutant viruses at the NPT showed that both ICP0 and ts forms of ICP4 were localized predominantly within the nucleus. These observations are a further indication that the aberrant localization of the ts forms of ICP4 at the NPT is not a direct result of specific mutations in the ICP4 gene. In the final series of tests, the localization of ICP0 in cells infected with a double-mutant virus unable to express either ICP4 or ICP27 was examined. In these tests, ICP0 was detected exclusively in the nuclei of Vero cells but in both the nuclei and the cytoplasms of ICP27-expressing cells infected with the double mutant. These results demonstrate that ICP27, rather than the absence of functional ICP4, is responsible for the cytoplasmic localization of ICP0 in ICP4 mutant virus-infected cells. Taken together, these findings demonstrate that the aberrant localization of ICP0 and certain mutant forms of ICP4 in cells infected with ICP4 mutant viruses is mediated by high levels of ICP27 resulting from the inability of mutant forms of ICP4 to repress the expression of ICP27. 相似文献
9.
Stratigraphy of cladoceran remains in the upper 18 cm of a sediment core from the Lake Černé was studied. The successive disappearance
of Bosmina longispina, Daphnia longispina and Ceriodaphnia quadrangula from the upper layers of the sediment corresponds with our knowledge concerning the disappearance of these species from the
open water. 相似文献
10.