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191.
In standard tissue culture conditions (20% oxygen), single human dermal fibroblasts (one cell per well) do not proliferate. We now report that low oxygen tension is a potent stimulus for the proliferation and expansion of human adult and neonatal dermal fibroblasts seeded as single cells. This preferential single-cell proliferation in low oxygen is shown to be also a feature of human lung and dermal rodent fibroblasts, but not of human fibrosarcoma and immortalized 3T3 cells, which proliferate without difficulty in standard oxygen conditions. It is suggested that single-cell proliferation and its dramatic stimulation in low oxygen may represent a fundamental biologic process with an opportunity to better understand mammalian cell growth regulation. © 1993 Wiley-Liss, Inc. 相似文献
192.
Mark D. Vincent 《BioEssays : news and reviews in molecular, cellular and developmental biology》2017,39(9)
General theories (GT) are reductionist explications of apparently independent facts. Here, in reviewing the literature, I develop a GT to simplify the cluttered landscape of cancer therapy targets by revealing they cluster parsimoniously according to only a few underlying principles. The first principle is that targets can be only exploited by either or both of two fundamentally different approaches: causality‐inhibition, and ‘acausal’ recognition of some marker or signature. Nonetheless, each approach must achieve both of two separate goals, efficacy (reduction in cancer burden) and selectivity (sparing of normal cells); if the mechanisms are known, this provides a definition of rational treatment. The second principle is target fragmentation, whereby the target may perform up to three categoric functions (cytoreduction, modulation, cytoprotection), potentially mediated by physically different target molecules, even on different cell types, or circulating freely. This GT remains incomplete until the minimal requirements for cure, or alternatively, proof that cure is impossible, become predictable. 相似文献
193.
Vincent D. Harris 《BMJ (Clinical research ed.)》1900,2(2086):1822-1823
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Lapeña David Olsen Pernille M. Arntzen Magnus Ø. Kosa Gergely Passoth Volkmar Eijsink Vincent G. H. Horn Svein J. 《Bioprocess and biosystems engineering》2020,43(4):723-736
Bioprocess and Biosystems Engineering - The production of microbial protein in the form of yeast grown on lignocellulosic sugars and nitrogen-rich industrial residues is an attractive approach for... 相似文献
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Bethany S. Nichols Gerhard Leubner‐Metzger Vincent A. A. Jansen 《Ecology letters》2020,23(9):1370-1379
Environmental variability can lead to dispersal: why stay put if it is better elsewhere? Without clues about local conditions, the optimal strategy is often to disperse a set fraction of offspring. Many habitats contain environmentally differing sub‐habitats. Is it adaptive for individuals to sense in which sub‐habitat they find themselves, using environmental clues, and respond plastically by altering the dispersal rates? This appears to be done by some plants which produce dimorphic seeds with differential dispersal properties in response to ambient temperature. Here we develop a mathematical model to show, that in highly variable environments, not only does sensing promote plasticity of dispersal morph ratio, individuals who can sense their sub‐habitat and respond in this way have an adaptive advantage over those who cannot. With a rise in environmental variability due to climate change, our understanding of how natural populations persist and respond to changes has become crucially important. 相似文献
200.
Victoire Cardot‐Ruffino Vronique Chauvet Cassandre Caligaris Adrien Bertrand‐Chapel Nicolas Chuvin Roxane M. Pommier Ulrich Valcourt David Vincent Sylvie Martel Sophie Aires Bastien Kaniewski Pierre Dubus Philippe Cassier Stphanie Sentis Laurent Bartholin 《Genesis (New York, N.Y. : 2000)》2020,58(5)
Recombination systems represent a major breakthrough in the field of genetic model engineering. The Flp recombinases (Flp, Flpe, and Flpo) bind and cleave DNA Frt sites. We created a transgenic mouse strain ([Fsp1‐Flpo]) expressing the Flpo recombinase in fibroblasts. This strain was obtained by random insertion inside mouse zygotes after pronuclear injection. Flpo expression was placed under the control of the promoter of Fsp1 (fibroblast‐specific protein 1) gene, whose expression starts after gastrulation at Day 8.5 in cells of mesenchymal origin. We verified the correct expression and function of the Flpo enzyme by several ex vivo and in vivo approaches. The [Fsp1‐Flpo] strain represents a genuine tool to further target the recombination of transgenes with Frt sites specifically in cells of mesenchymal origin or with a fibroblastic phenotype. 相似文献