全文获取类型
收费全文 | 3732篇 |
免费 | 330篇 |
国内免费 | 2篇 |
出版年
2023年 | 14篇 |
2022年 | 48篇 |
2021年 | 72篇 |
2020年 | 41篇 |
2019年 | 58篇 |
2018年 | 93篇 |
2017年 | 63篇 |
2016年 | 129篇 |
2015年 | 199篇 |
2014年 | 219篇 |
2013年 | 257篇 |
2012年 | 334篇 |
2011年 | 305篇 |
2010年 | 192篇 |
2009年 | 178篇 |
2008年 | 217篇 |
2007年 | 237篇 |
2006年 | 212篇 |
2005年 | 185篇 |
2004年 | 154篇 |
2003年 | 153篇 |
2002年 | 149篇 |
2001年 | 49篇 |
2000年 | 28篇 |
1999年 | 46篇 |
1998年 | 35篇 |
1997年 | 35篇 |
1996年 | 26篇 |
1995年 | 17篇 |
1994年 | 20篇 |
1993年 | 20篇 |
1992年 | 29篇 |
1991年 | 23篇 |
1990年 | 14篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 20篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1974年 | 6篇 |
1971年 | 5篇 |
1957年 | 5篇 |
1946年 | 4篇 |
排序方式: 共有4064条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
zge Karayel Francesca Tonelli Sebastian Virreira Winter Phillip E. Geyer Ying Fan Esther M. Sammler Dario R. Alessi Martin Steger Matthias Mann 《Molecular & cellular proteomics : MCP》2020,19(9):1546-1560
Highlights
- •MS-based clinical assay that accurately determines phospho Rab10 occupancy.
- •Stable isotope labeled phosphopeptide injected as a standard with endogenous tryptic phospho Rab peptide for accurate ratio determination.
- •Determination of pRab levels in neutrophils of Parkinson disease patients.
- •Relevance of pRab levels as marker of PD.
5.
6.
Thirty components were identified in Lavandula latifolia essential oil (spike oil). One of the compounds, espliegol (δ-terpineol), is a new natural product. 相似文献
7.
Food subsidies have the potential to modify ecosystems and affect the provision of goods and services. Predictable Anthropogenic Food Subsidies (PAFS) modify ecosystems by altering ecological processes and food webs. The global concern over the effects of PAFS in ecosystems has led to development of environmental policies aimed at curbing the production or ultimately banning of PAFS. However, the effects of reducing or banning PAFS are not known. We explore the consequences of PAFS removal in a marine ecosystem under two scenarios: 1) gradual reduction, or 2) an abrupt ban, using a mass balance model to test these hypotheses–The reduction or loss of PAFS will: i) modify trophic levels and food webs through effects on foraging by opportunistic species, ii) increase the resilience of opportunistic species to food shortages, and iii) modify predator–prey interactions through shifts in prey consumption. We found that PAFS lower the trophic levels of opportunistic scavengers and increase their food pathways. Scavengers are able to switch prey when PAFS are reduced gradually but they decline when PAFS are abruptly banned. PAFS reduction to a certain minimal level causes a drop in the ecosystem’s stability. We recommend gradual reduction of PAFS to a minimal level that would maintain the ecosystem’s stability and allow species exploiting PAFS to habituate to the food subsidy reduction. 相似文献
8.
9.
10.
Francisco Javier Caballero Isabel Igeño Jacobo Cárdenas Francisco Castillo 《Archives of microbiology》1989,152(5):508-511
The phototrophic bacterium Rhodobacter capsulatus E1F1 assimilates ammonia and other forms of reduced nitrogen either through the GS/GOGAT pathway or by the concerted action of l-alanine dehydrogenase and aminotransferases. These routes are light-independent and very responsive to the carbon and nitrogen sources used for cell growth. GS was most active in cells grown on nitrate or l-glutamate as nitrogen sources, whereas it was heavily adenylylated and siginificantly repressed by ammonium, glycine, l-alanine, l-aspartate, l-asparagine and l-glutamine, under which conditions specific aminotransferases were induced. GOGAT activity was kept at constitutive levels in cells grown on l-amino acids as nitrogen sources except on l-glutamine where it was significantly induced during the early phase of growth. In vitro, GOGAT activity was strongly inhibited by l-tyrosine and NADPH. In cells using l-asparagine or l-aspartate as nitrogen source, a concerted induction of l-aspartate aminotransferase and l-asparaginase was observed. Enzyme level enhancements in response to nitrogen source variation involved de novo protein synthesis and strongly correlated with the cell growth phase.Abbreviations ADH
l-alanine dehydrogenase
- AOAT
l-alanine:2-oxoglutarate aminotransferase
- Asnase
l-asparaginase
- GOAT
Glycine: oxaloacetate aminotransferase
- GOGAT
Glutamate synthase
- GOT
l-aspartate: 2-oxoglutarate aminotransferase
- GS
Glutamine synthetase
- HPLC
High-Pressure Liquid Chromatography
- MOPS
2-(N-morpholino)propanesulfonic acid
- MSX
l-methionine-d,l-sulfoximine 相似文献