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621.
Zusammenfassung Es wird eine stufenphotometrische Methode beschrieben, welche es ermöglicht, in 0,2 cm3 Blutserum bzw. plasma Natrium, Reststickstoff und Gesamteiweiß nebeneinander zu bestimmen. 相似文献
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623.
Ciruela F Ferré S Casadó V Cortés A Cunha RA Lluis C Franco R 《Cellular and molecular life sciences : CMLS》2006,63(21):2427-2431
Since 1990 it has been known that dimers are the basic functional form of nearly all G-protein-coupled receptors (GPCRs) and
that homo- and heterodimerization may play a key role in correct receptor maturation and trafficking to the plasma membrane.
Nevertheless, homo- and heterodimerization of GPCR has become a matter of debate especially in the search for the precise
physiological meaning of this phenomenon. This article focuses on how heterodimerization of adenosine A1 and A2A receptors, which are coupled to apparently opposite signalling pathways, allows adenosine to exert a fine-tuning modulation
of striatal glutamatergic neurotransmission, providing a switch mechanism by which low and high concentrations of adenosine
inhibit and stimulate, respectively, glutamate release.
Received 8 May 2006; received after revision 19 June 2006; accepted 17 July 2006 相似文献
624.
A truncating mutation of HDAC2 in human cancers confers resistance to histone deacetylase inhibition 总被引:1,自引:0,他引:1
Ropero S Fraga MF Ballestar E Hamelin R Yamamoto H Boix-Chornet M Caballero R Alaminos M Setien F Paz MF Herranz M Palacios J Arango D Orntoft TF Aaltonen LA Schwartz S Esteller M 《Nature genetics》2006,38(5):566-569
Disruption of histone acetylation patterns is a common feature of cancer cells, but very little is known about its genetic basis. We have identified truncating mutations in one of the primary human histone deacetylases, HDAC2, in sporadic carcinomas with microsatellite instability and in tumors arising in individuals with hereditary nonpolyposis colorectal cancer syndrome. The presence of the HDAC2 frameshift mutation causes a loss of HDAC2 protein expression and enzymatic activity and renders these cells more resistant to the usual antiproliferative and proapoptotic effects of histone deacetylase inhibitors. As such drugs may serve as therapeutic agents for cancer, our findings support the use of HDAC2 mutational status in future pharmacogenetic treatment of these individuals. 相似文献
625.
Molecular pathways driving disease-specific alterations of intestinal epithelial cells 总被引:1,自引:1,他引:0
Rocío López-Posadas Markus F. Neurath Imke Atreya 《Cellular and molecular life sciences : CMLS》2017,74(5):803-826
Due to the fact that chronic inflammation as well as tumorigenesis in the gut is crucially impacted by the fate of intestinal epithelial cells, our article provides a comprehensive overview of the composition, function, regulation and homeostasis of the gut epithelium. In particular, we focus on those aspects which were found to be altered in the context of inflammatory bowel diseases or colorectal cancer and also discuss potential molecular targets for a disease-specific therapeutic intervention. 相似文献
626.
Verónica Parrillas Laura Martínez-Muñoz Borja L. Holgado Amit Kumar Graciela Cascio Pilar Lucas José Miguel Rodríguez-Frade Marcos Malumbres Ana C. Carrera Karel HM van Wely Mario Mellado 《Cellular and molecular life sciences : CMLS》2013,70(3):545-558
Hypermethylation of SOCS genes is associated with many human cancers, suggesting a role as tumor suppressors. As adaptor molecules for ubiquitin ligases, SOCS proteins modulate turnover of numerous target proteins. Few SOCS targets identified so far have a direct role in cell cycle progression; the mechanism by which SOCS regulate the cell cycle thus remains largely unknown. Here we show that SOCS1 overexpression inhibits in vitro and in vivo expansion of human melanoma cells, and that SOCS1 associates specifically with Cdh1, triggering its degradation by the proteasome. Cells therefore show a G1/S transition defect, as well as a secondary blockade in mitosis and accumulation of cells in metaphase. SOCS1 expression correlated with a reduction in cyclin D/E levels and an increase in the tumor suppressor p19, as well as the CDK inhibitor p53, explaining the G1/S transition defect. As a result of Cdh1 degradation, SOCS1-expressing cells accumulated cyclin B1 and securin, as well as apparently inactive Cdc20, in mitosis. Levels of the late mitotic Cdh1 substrate Aurora A did not change. These observations comprise a hitherto unreported mechanism of SOCS1 tumor suppression, suggesting this molecule as a candidate for the design of new therapeutic strategies for human melanoma. 相似文献
627.
Morgado M Cairrão E Santos-Silva AJ Verde I 《Cellular and molecular life sciences : CMLS》2012,69(2):247-266
Vascular smooth muscle tone is controlled by a balance between the cellular signaling pathways that mediate the generation
of force (vasoconstriction) and release of force (vasodilation). The initiation of force is associated with increases in intracellular
calcium concentrations, activation of myosin light-chain kinase, increases in the phosphorylation of the regulatory myosin
light chains, and actin-myosin crossbridge cycling. There are, however, several signaling pathways modulating Ca2+ mobilization and Ca2+ sensitivity of the contractile machinery that secondarily regulate the contractile response of vascular smooth muscle to
receptor agonists. Among these regulatory mechanisms involved in the physiological regulation of vascular tone are the cyclic
nucleotides (cAMP and cGMP), which are considered the main messengers that mediate vasodilation under physiological conditions.
At least four distinct mechanisms are currently thought to be involved in the vasodilator effect of cyclic nucleotides and
their dependent protein kinases: (1) the decrease in cytosolic calcium concentration ([Ca2+]c), (2) the hyperpolarization of the smooth muscle cell membrane potential, (3) the reduction in the sensitivity of the contractile
machinery by decreasing the [Ca2+]c sensitivity of myosin light-chain phosphorylation, and (4) the reduction in the sensitivity of the contractile machinery
by uncoupling contraction from myosin light-chain phosphorylation. This review focuses on each of these mechanisms involved
in cyclic nucleotide-dependent relaxation of vascular smooth muscle under physiological conditions. 相似文献
628.
629.
630.
The structure of grassland communities can vary widely in response to heterogeneous habitat variables. In this study we document plant communities, soil types, and site characteristics for 12 Palouse prairie remnants in southeastern Washington and northern Idaho. We used general linear models to test the predictive value of 6 biophysical variables (slope, aspect, distance from edge, edge type, vegetation structure, and soil type) on 3 plant community metrics: species richness, Simpson’s diversity index, and the dominance of exotic species. From full models including all variables, we used Akaike’s information criterion (AIC) to select the best model for each metric. Aspect and vegetation structure were significant predictors of species richness ( R 2 = 0.08) and diversity ( R 2 = 0.09), while aspect, soil type, distance from edge, and edge type (type of adjacent matrix habitat) influenced the dominance of exotic species ( R 2 = 0.28). Additional soil sampling determined that the depth to a restrictive layer also had significant impacts on the dominance of exotic species ( R 2 = 0.31). This study confirms that biophysical characteristics influence Palouse prairie plant communities and may help set research and conservation priorities for isolated and uninventoried remnants. 相似文献