全文获取类型
收费全文 | 26384篇 |
免费 | 2320篇 |
出版年
2023年 | 105篇 |
2021年 | 236篇 |
2020年 | 167篇 |
2019年 | 208篇 |
2018年 | 469篇 |
2017年 | 471篇 |
2016年 | 585篇 |
2015年 | 684篇 |
2014年 | 842篇 |
2013年 | 1080篇 |
2012年 | 1819篇 |
2011年 | 1906篇 |
2010年 | 1060篇 |
2009年 | 734篇 |
2008年 | 1553篇 |
2007年 | 1546篇 |
2006年 | 1448篇 |
2005年 | 1335篇 |
2004年 | 1248篇 |
2003年 | 1166篇 |
2002年 | 1165篇 |
2001年 | 929篇 |
2000年 | 1092篇 |
1999年 | 573篇 |
1998年 | 275篇 |
1997年 | 202篇 |
1996年 | 263篇 |
1995年 | 210篇 |
1994年 | 206篇 |
1993年 | 196篇 |
1992年 | 258篇 |
1991年 | 256篇 |
1990年 | 250篇 |
1989年 | 193篇 |
1988年 | 230篇 |
1987年 | 220篇 |
1986年 | 189篇 |
1985年 | 236篇 |
1984年 | 228篇 |
1983年 | 187篇 |
1982年 | 210篇 |
1981年 | 196篇 |
1980年 | 134篇 |
1979年 | 196篇 |
1978年 | 134篇 |
1977年 | 138篇 |
1976年 | 113篇 |
1975年 | 130篇 |
1974年 | 120篇 |
1973年 | 123篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
41.
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
42.
43.
Reinhard Told Stefan Palkovits Helmuth Haslacher Sophie Frantal Doreen Schmidl Agnes Boltz Michael Lasta Semira Kaya René M. Werkmeister Gerhard Garh?fer Leopold Schmetterer 《PloS one》2013,8(4)
A common polymorphism in the complement factor H gene (rs1061170, Y402H) is associated with a high risk of age-related macular degeneration (AMD). In the present study we hypothesized that healthy young subjects homozygous for the high-risk haplotype (CC) show abnormal choroidal blood flow (ChBF) regulation decades before potentially developing the disease. A total of 100 healthy young subjects were included in the present study, of which 4 subjects were excluded due to problems with genotyping or blood flow measurements. ChBF was measured continuously using laser Doppler flowmetry while the subjects performed isometric exercise (squatting) for 6 minutes. The increase in ChBF was less pronounced than the response in ocular perfusion pressure (OPP), indicating for some degree of choroidal blood flow regulation. Eighteen subjects were homozygous for C, 47 subjects were homozygous for T and 31 subjects were heterozygous (CT). The increase in OPP during isometric exercise was not different between groups. By contrast the increase in ChBF was more pronounced in subjects homozygous for the high risk C allele (p = 0.041). This was also evident from the pressure/flow relationship, where the increase in ChBF in homozygous C carriers started at lower OPPs as compared to the other groups. Our data indicate that the regulation of ChBF is abnormal in rs1061170 CC carriers. So far this polymorphism has been linked to age related macular degeneration (AMD) mainly via inflammatory pathways associated with the complement system dysfunction. Our results indicate that it could also be related to vascular factors that have been implicated in AMD pathogenesis. 相似文献
44.
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
45.
46.
47.
48.
Ferdinand Täuber 《Folia Geobotanica》1985,20(1):1-16
The importance of endemic species for plant communities in the Roumanian Carpathians Mts. has been studied and discussed. Associations of the classAsplenietea trichomanis endemic in the South Carpathians were surveyed; they were classified into some endemic alliances (Gypsophilion petraeae, Micromerion pulegii, andSilenion lerchenfeldianae). Their locus classicus, nomenclatoric type and present distribution were also given. 相似文献
49.
Friedrich Häusele 《Cell and tissue research》1932,16(2):484-496
Ohne ZusammenfassungFrühere Zahnstudien erschienen in dieser Zeitschrift von H. Marcus und seinen Schülern. 相似文献
50.