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931.
The binding of 3H-corticosterone and 3H-11-dehydrocorticosterone to receptors in cytosol and nucleus was examined in fetal mouse brain and placenta using Sephadex gel filtration or charcoal to separate bound and unbound steroid. In the cytosol, competitive displacement of each steroid by the other was observed. The binding was unaffected by RNase, DNase, dithiothreitol or N-ethyl maleimide but was diminished by Pronase. Nuclei were isolated by hypotonic shock using dilute MgCl2 and the steroid receptor-complexes of both steroids were obtained from the nuclear sap. Receptor-complexes of both steroids were observed in brain and placental tissues. Competitive displacement of each steroid by the other was also observed in nuclear binding. Both 11-dehydrocorticosterone and 11-deoxycorticosterone bound to a chromatin fraction as did the hormone corticosterone. Identity of the steroids was established by using chromatography and co-crystallization techniques. This work raises the possibility that in the fetal mouse, 11-dehydrocorticosterone, previously considered biologically inactive and an abundant metabolite in fetal mouse tissues, may in fact play a more positive role in regulation. 相似文献
932.
L V Filev V G Popov I V Volchek S F Enokhin Iu V Medvedev 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1985,(11):72-76
The influence of interlok, biotop and remantadine on the functional activity of monocytes was determined with the use of the NBT test permitting the quantitative evaluation of this characteristic. In this study interlok was found to give promising results in the treatment of acute viral hepatitis, due both to its antiviral action and to the stimulation of the functional activity of monocytes. biotop proved to render a sharply pronounced stimulating effect on the functional activity of monocytes, thus enhancing antiviral resistance. Remantadine suppressed the functional activity of monocytes and increased their lesion by the virus, thus creating favorable conditions for virus persistence in monocytes. 相似文献
933.
G Iu Miterev G F Burova M S Puzhitskaia S V Danilevich T I Bulycheva 《Biulleten' eksperimental'no? biologii i meditsiny》1987,103(6):710-712
Two hybridomas secreting mouse cytotoxic monoclonal antibodies to in vivo and in vitro activated human T-lymphocyte and neutrophil surface membrane antigenic determinants have been produced. One of these monoclonal antibodies (Ta/H-2) appeared to be also specifically reactive to blast cells in the majority of non-T-non-B and T acute lymphoblastic leukemia patients. 相似文献
934.
A Ca2+-insensitive form of fura-2 associated with polymorphonuclear leukocytes. Assessment and accurate Ca2+ measurement 总被引:23,自引:0,他引:23
The new, fluorescent Ca2+ indicator, fura-2, promises to expand our understanding of the role of subcellular changes in Ca2+ underlying cell function. During an investigation of the role of Ca2+ in the polarization response of human polymorphonuclear leukocytes to formyl-methionyl-leucyl-phenylalanine, we found that fura-2 trapped by cells incubated with the acetoxy-methyl ester of fura-2, F2-AM, yielded measurements of Ca2+ that were depressed at rest and during the response to formyl-methionyl-leucyl-phenylalanine. Fura-2, trapped by the cells, exhibited a spectrum in the presence of saturating Ca2+ that differed from that of fura-2 free acid. We have shown that the cellular fluorescence can be spectrally decomposed into two components: one with Ca2+ sensitivity identical to fully deesterified fura-2, and another which is Ca2+-insensitive. The Ca2+-insensitive component appears to be more fluorescent than F2-AM as well as spectrally different from F2-AM. The insensitive form probably results from incomplete deesterification of F2-AM by the cells. In order to accurately measure Ca2+ in polymorphonuclear leukocytes, it is imperative to check for the presence of Ca2+-insensitive fluorescence. The contribution of Ca2+-insensitive fura-2 fluorescence can be assessed routinely from spectral data obtained by calibration of intracellular fura-2 with known [Ca2+] using ionomycin. The end-of-experiment calibration step not only ensures accurate [Ca2+] measurements in polymorphonuclear leukocytes and in other cell types that display Ca2+-insensitive, contaminating fluorescence but also yields the spectral characteristics of the insensitive species. 相似文献
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940.
M J Schilstra J W Slot P H van der Meide G Posthuma A F Cremers L Bosch 《FEBS letters》1984,165(2):175-179
The localization of the elongation factor Tu (EF-Tu) in ultrathin cryosections of E. coli cells was determined with the electron microscope using a highly specific immunological labelling technique. EF-Tu is distributed almost homogeneously throughout the cytoplasm. Although it has often been suggested that EF-Tu could be part of a putative prokaryotic cytoskeleton, we did not find any evidence for supramolecular assemblies, such as fibres or filaments, containing a large amount of EF-Tu. EF-Tu was not observed in association with the outer cell membrane and periplasmic space. A topological relationship with the inner membrane is not apparent in our micrographs. In cells in which the EF-Tu level is raised significantly, the protein piles up in discrete cell regions. 相似文献