全文获取类型
收费全文 | 1466篇 |
免费 | 93篇 |
国内免费 | 1篇 |
出版年
2022年 | 12篇 |
2021年 | 29篇 |
2020年 | 17篇 |
2019年 | 25篇 |
2018年 | 33篇 |
2017年 | 31篇 |
2016年 | 49篇 |
2015年 | 49篇 |
2014年 | 67篇 |
2013年 | 79篇 |
2012年 | 94篇 |
2011年 | 93篇 |
2010年 | 58篇 |
2009年 | 58篇 |
2008年 | 62篇 |
2007年 | 69篇 |
2006年 | 48篇 |
2005年 | 68篇 |
2004年 | 43篇 |
2003年 | 35篇 |
2002年 | 29篇 |
2001年 | 17篇 |
2000年 | 26篇 |
1999年 | 23篇 |
1995年 | 6篇 |
1993年 | 6篇 |
1992年 | 17篇 |
1991年 | 25篇 |
1990年 | 24篇 |
1989年 | 29篇 |
1988年 | 17篇 |
1987年 | 19篇 |
1986年 | 19篇 |
1985年 | 21篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 23篇 |
1979年 | 24篇 |
1978年 | 11篇 |
1977年 | 16篇 |
1976年 | 15篇 |
1975年 | 14篇 |
1974年 | 20篇 |
1973年 | 10篇 |
1972年 | 10篇 |
1971年 | 12篇 |
1970年 | 9篇 |
1969年 | 9篇 |
排序方式: 共有1560条查询结果,搜索用时 46 毫秒
71.
72.
73.
74.
Linfang Shen Xudong Chen Xufeng Zhang Krishna Agarwal 《Plasmonics (Norwell, Mass.)》2011,6(2):301-305
In this paper, we show that surface plasmon polaritons (SPPs) can be sustained by a single row of holes periodically drilled
on a perfect electric conductor surface. These SPPs can be strongly confined in the transverse plane and they possess an excellent
modal shape. In the terahertz regime, large propagation length is available for highly confined SPPs on a real-metal surface
waveguide. As the dispersion characteristics of such SPPs can be controlled by the surface geometry, unusual total reflection
phenomenon occurs when waves travel along a nonuniform surface waveguide with gradually increasing hole depths. 相似文献
75.
Shireesha Sankella Abhimanyu Garg Jay D. Horton Anil K. Agarwal 《The Journal of biological chemistry》2014,289(8):4762-4777
In this study we examined the role of phosphatidic acid (PA) in hepatic glucose production (HGP) and development of hepatic insulin resistance in mice that lack 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2). Liver lysophosphatidic acid and PA levels were increased ∼2- and ∼5-fold, respectively, in male Agpat2−/− mice compared with wild type mice. In the absence of AGPAT2, the liver can synthesize PAs by activating diacylglycerol kinase or phospholipase D, both of which were elevated in the livers of Agpat2−/− mice. We found that PAs C16:0/18:1 and C18:1/20:4 enhanced HGP in primary WT hepatocytes, an effect that was further enhanced in primary hepatocytes from Agpat2−/− mice. Lysophosphatidic acids C16:0 and C18:1 failed to increase HGP in primary hepatocytes. The activation of HGP was accompanied by an up-regulation of the key gluconeogenic enzymes glucose-6-phosphatase and phosphoenolpyruvate carboxykinase. This activation was suppressed by insulin in the WT primary hepatocytes but not in the Agpat2−/− primary hepatocytes. Thus, the lack of normal insulin signaling in Agpat2−/− livers allows unrestricted PA-induced gluconeogenesis significantly contributing to the development of hyperglycemia in these mice. 相似文献
76.
Anna M. Blom Simone Bergmann Marcus Fulde Kristian Riesbeck Vaibhav Agarwal 《The Journal of biological chemistry》2014,289(47):32499-32511
The Gram-positive bacterium Streptococcus pneumoniae is a major human pathogen that causes infections ranging from acute otitis media to life-threatening invasive disease. Pneumococci have evolved several strategies to circumvent the host immune response, in particular the complement attack. The pneumococcal glycolytic enzyme phosphoglycerate kinase (PGK) is both secreted and bound to the bacterial surface and simultaneously binds plasminogen and its tissue plasminogen activator tPA. In the present study we demonstrate that PGK has an additional role in modulating the complement attack. PGK interacted with the membrane attack complex (MAC) components C5, C7, and C9, thereby blocking the assembly and membrane insertion of MAC resulting in significant inhibition of the hemolytic activity of human serum. Recombinant PGK interacted in a dose-dependent manner with these terminal pathway proteins, and the interactions were ionic in nature. In addition, PGK inhibited C9 polymerization both in the fluid phase and on the surface of sheep erythrocytes. Interestingly, PGK bound several MAC proteins simultaneously. Although C5 and C7 had partially overlapping binding sites on PGK, C9 did not compete with either one for PGK binding. Moreover, PGK significantly inhibited MAC deposition via both the classical and alternative pathway at the pneumococcal surface. Additionally, upon activation plasmin(ogen) bound to PGK cleaved the central complement protein C3b thereby further modifying the complement attack. In conclusion, our data demonstrate for the first time to our knowledge a novel pneumococcal inhibitor of the terminal complement cascade aiding complement evasion by this important pathogen. 相似文献
77.
78.
Kumar Ritesh Khungar Lisha Shimphrui Rinchuila Tiwari Lalit Dev Tripathi Gayatri Sarkar Neelam K. Agarwal Surekha-Katiyar Agarwal Manu Grover Anil 《Journal of plant biochemistry and biotechnology.》2020,29(4):715-732
Journal of Plant Biochemistry and Biotechnology - Caseinolytic protease (Clp)/Hsp100 proteins are members of the AAA+ (ATPase associated with a variety of cellular activities) family of proteins... 相似文献
79.
80.