全文获取类型
收费全文 | 4937篇 |
免费 | 420篇 |
国内免费 | 3篇 |
专业分类
5360篇 |
出版年
2024年 | 3篇 |
2023年 | 32篇 |
2022年 | 77篇 |
2021年 | 135篇 |
2020年 | 69篇 |
2019年 | 101篇 |
2018年 | 92篇 |
2017年 | 94篇 |
2016年 | 173篇 |
2015年 | 284篇 |
2014年 | 307篇 |
2013年 | 382篇 |
2012年 | 462篇 |
2011年 | 463篇 |
2010年 | 274篇 |
2009年 | 260篇 |
2008年 | 361篇 |
2007年 | 329篇 |
2006年 | 318篇 |
2005年 | 278篇 |
2004年 | 240篇 |
2003年 | 218篇 |
2002年 | 182篇 |
2001年 | 21篇 |
2000年 | 15篇 |
1999年 | 29篇 |
1998年 | 33篇 |
1997年 | 22篇 |
1996年 | 29篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有5360条查询结果,搜索用时 0 毫秒
41.
42.
Dan H. Barouch Kathryn E. Stephenson Erica N. Borducchi Kaitlin Smith Kelly Stanley Anna G. McNally Jinyan Liu Peter Abbink Lori F. Maxfield Michael S. Seaman Anne-Sophie Dugast Galit Alter Melissa Ferguson Wenjun Li Patricia L. Earl Bernard Moss Elena E. Giorgi James J. Szinger Leigh Anne Eller Erik A. Billings Mangala Rao Sodsai Tovanabutra Eric Sanders-Buell Mo Weijtens Maria G. Pau Hanneke Schuitemaker Merlin L. Robb Jerome H. Kim Bette T. Korber Nelson L. Michael 《Cell》2013
43.
Normal enteric nervous system (ENS) development relies on numerous factors, including appropriate migration, proliferation, differentiation, and maturation of neural crest (NC) derivatives. Incomplete rostral to caudal migration of enteric neural crest-derived progenitors (ENPs) down the gut is at least partially responsible for the absence of enteric ganglia that is a hallmark feature of Hirschsprung disease (HSCR). The thought that ganglia proximal to aganglionosis are normal has guided surgical procedures for HSCR patients. However, chronic gastrointestinal dysfunction suffered by a subset of patients after surgery as well as studies in HSCR mouse models suggest that aberrant NC segregation and differentiation may be occurring in ganglionated regions of the intestine. Studies in mouse models that possess enteric ganglia throughout the length of the intestine (non-HSCR) have also found that certain genetic alterations affect neural crest lineage balance and interestingly many of these mutants also have functional gastrointestinal (GI) defects. It is possible that many GI disorders can be explained in part by imbalances in NC-derived lineages. Here we review studies evaluating ENS defects in HSCR and non-HSCR mouse models, concluding with clinical implications while highlighting areas requiring further study. 相似文献
44.
Melissa L. Caldwell 《Ethnos》2013,78(3):295-319
In this article I consider how Muscovites cultivate and express nationalist sentiments through their food choices. During the last ten years of the post-socialist transition, Russian consumers have encountered an expanding and increasingly transnational commodity market. Locally produced elements of Russian cuisine both compete with and imitate foreign food products. In response to perceptions that foreign cultures are displacing or subsuming local cultural forms, Russian officials have launched a 'Buy Russian' campaign. Domestic food producers, store clerks, and customers collaborate to classify foods and other products as either 'Ours'(Nash) or 'Not Ours' (Ne nash) and describe local goods as superior to foreign goods in terms of taste, quality, and healthfulness. In their own narratives about consumption choices, Muscovites echo these nationalist themes by explicitly linking their personal food experiences with broader political issues. Drawing from ethnographic fieldwork on foodpractices in Moscow(1995-2001), I suggest that consumption strategies mediate Muscovites' experiences with growing nationalist sentiments in the context of a globalizing Russia. 相似文献
45.
Scott J. Gratz Alexander M. Cummings Jennifer N. Nguyen Danielle C. Hamm Laura K. Donohue Melissa M. Harrison Jill Wildonger Kate M. O’Connor-Giles 《Genetics》2013,194(4):1029-1035
We have adapted a bacterial CRISPR RNA/Cas9 system to precisely engineer the Drosophila genome and report that Cas9-mediated genomic modifications are efficiently transmitted through the germline. This RNA-guided Cas9 system can be rapidly programmed to generate targeted alleles for probing gene function in Drosophila. 相似文献
46.
47.
48.
Kevin Lewellyn Dobroslawa Bialonska Melissa J. Loria Stephen W. White Kenneth J. Sufka Jordan K. Zjawiony 《Bioorganic & medicinal chemistry》2013,21(22):7083-7090
Aplysinopsins are tryptophan-derived natural products that have been isolated from a variety of marine organisms and have been shown to possess a range of biological activities. In vitro receptor binding assays showed that of the 12 serotonin receptor subtypes, analogues showed a high affinity for the 5-HT2B and 5-HT2C receptor subtypes, with selectivity for 5-HT2B over 5-HT2C. While no conclusions could be drawn about the number and position of N-methylations, bromination at C-4 and C-5 of the indole ring resulted in greater binding affinities, with Ki’s as low as 35 nM. This data, combined with previous knowledge of the CNS activity of aplysinopsin analogs, suggested that these compounds may have potential as leads for antidepressant drugs. Compounds 3c, 3u, and 3x were evaluated in the chick anxiety–depression model to assess their in vivo efficacy. Compound 3c showed a modest antidepressant effect at a dose of 30 nM/kg in the animal model. 相似文献
49.
50.