全文获取类型
收费全文 | 21264篇 |
免费 | 1869篇 |
出版年
2023年 | 81篇 |
2021年 | 167篇 |
2020年 | 117篇 |
2019年 | 145篇 |
2018年 | 379篇 |
2017年 | 399篇 |
2016年 | 428篇 |
2015年 | 373篇 |
2014年 | 495篇 |
2013年 | 795篇 |
2012年 | 1434篇 |
2011年 | 1550篇 |
2010年 | 810篇 |
2009年 | 565篇 |
2008年 | 1321篇 |
2007年 | 1316篇 |
2006年 | 1271篇 |
2005年 | 1130篇 |
2004年 | 1067篇 |
2003年 | 1047篇 |
2002年 | 1043篇 |
2001年 | 795篇 |
2000年 | 911篇 |
1999年 | 430篇 |
1998年 | 238篇 |
1997年 | 185篇 |
1996年 | 229篇 |
1995年 | 208篇 |
1994年 | 186篇 |
1993年 | 177篇 |
1992年 | 155篇 |
1991年 | 149篇 |
1990年 | 153篇 |
1989年 | 145篇 |
1988年 | 138篇 |
1987年 | 136篇 |
1986年 | 138篇 |
1985年 | 172篇 |
1984年 | 188篇 |
1983年 | 152篇 |
1982年 | 196篇 |
1981年 | 182篇 |
1980年 | 142篇 |
1979年 | 140篇 |
1978年 | 117篇 |
1977年 | 110篇 |
1976年 | 101篇 |
1975年 | 98篇 |
1974年 | 108篇 |
1973年 | 84篇 |
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
21.
Monoclonal anti-mouse macrophage antibodies recognize the globular portions of C1q, a subcomponent of the first component of complement 总被引:1,自引:0,他引:1
H P Heinz H Dlugonska E Rüde M Loos 《Journal of immunology (Baltimore, Md. : 1950)》1984,133(1):400-404
One of seven monoclonal antibodies generated against mouse macrophages (M phi) was found to recognize isolated heterologous C1q. This antibody was shown to be cytotoxic and to react in a strain-independent way with mouse M phi derived from bone marrow cells as well as with M phi from the peritoneal cavity; it did not react, however, with mouse granulocytes, thymocytes, or T and B lymphocytes. The hemolytic activity of fluid phase C1q was inhibited to 50% at a 2 X 10(-4) dilution of hybridoma supernatant, whereas a 100-fold higher concentration was required to inhibit C1q bound to immune complexes ( EAC1q ) to the same extent. It was demonstrated that this antibody recognizes the isolated globular, Fc-binding portions of the C1q molecule and reacts with the A and B chains. Because M phi have been shown to synthesize C1q, the Fc-recognizing subcomponent of the first component of complement, evidence was provided that endogeneous C1q can serve as an Fc receptor on M phi during secretion. This fact was demonstrated by a dose-dependent inhibition of Fc-receptor activity for EIgG by the F(ab')2 fragment of this monoclonal antibody. These experiments further support the concept that C1q produced by M phi functions on the surface as an Fc-recognizing molecule before it is released and incorporated into the macromolecular complex of serum C1. 相似文献
22.
J. A. Bäumler 《Plant Systematics and Evolution》1890,40(1):17-19
Ohne Zusammenfassung 相似文献
23.
24.
Planar cell polarity (PCP) controls the orientation of cells within tissues and the polarized outgrowth of cellular appendages. So far, six PCP core proteins including the transmembrane proteins Frizzled (Fz), Strabismus (Stbm) and Flamingo (Fmi) have been identified. These proteins form asymmetric PCP domains at apical junctions of epithelial cells. Here, we demonstrate that VhaPRR, an accessory subunit of the proton pump V‐ATPase, directly interacts with the protocadherin Fmi through its extracellular domain. It also shows a striking co‐localization with PCP proteins during all pupal wing stages in Drosophila. This localization depends on intact PCP domains. Reversely, VhaPRR is required for stable PCP domains, identifying it as a novel PCP core protein. VhaPRR performs an additional role in vesicular acidification as well as endolysosomal sorting and degradation. Membrane proteins, such as E‐Cadherin and the Notch receptor, accumulate at the surface and in intracellular vesicles of cells mutant for VhaPRR. This trafficking defect is shared by other V‐ATPase subunits. By contrast, the V‐ATPase does not seem to have a direct role in PCP regulation. Together, our results suggest two roles for VhaPRR, one for PCP and another in endosomal trafficking. This dual function establishes VhaPRR as a key factor in epithelial morphogenesis. 相似文献
25.
26.
Jonas G. Barlind Linda K. Buckett Sharon G. Crosby Öjvind Davidsson Hans Emtenäs Anne Ertan Ulrik Jurva Malin Lemurell Pablo Morentin Gutierrez Karolina Nilsson Gavin O’Mahony Annika U. Petersson Alma Redzic Fredrik Wågberg Zhong-Qing Yuan 《Bioorganic & medicinal chemistry letters》2013,23(9):2721-2726
[Acyl CoA]monoacylglycerol acyltransferase 2 (MGAT2) is of interest as a target for therapeutic treatment of diabetes, obesity and other diseases which together constitute the metabolic syndrome. In this Letter we report our discovery and optimisation of a novel series of MGAT2 inhibitors. The development of the SAR of the series and a detailed discussion around some key parameters monitored and addressed during the lead generation phase will be given. The in vivo results from an oral lipid tolerance test (OLTT) using the MGAT2 inhibitor (S)-10, shows a significant reduction (68% inhibition relative to na?ve, p <0.01) in plasma triacylglycerol (TAG) concentration. 相似文献
27.
Acetobacter acetii DSMZ3508 and related bacteria converted 2,2-dimethyl-1,3-propanediol into 3-hydroxypivalic acid (2,2-dimethyl-3-hydroxypropionic acid; 3HP) during submerged cultivation in mineral salt medium. The maximum yield of 3-hydroxypivalic acid was 24.4% of the fed substrate after 18 days. Cultivation parameters, as pH, cell density, optimal substrate concentration, and oxygen supply for the bioconversion process were determined. 相似文献
28.
29.
30.