全文获取类型
收费全文 | 7988篇 |
免费 | 578篇 |
国内免费 | 1篇 |
出版年
2023年 | 36篇 |
2022年 | 30篇 |
2021年 | 125篇 |
2020年 | 80篇 |
2019年 | 118篇 |
2018年 | 141篇 |
2017年 | 137篇 |
2016年 | 239篇 |
2015年 | 392篇 |
2014年 | 450篇 |
2013年 | 497篇 |
2012年 | 740篇 |
2011年 | 707篇 |
2010年 | 461篇 |
2009年 | 409篇 |
2008年 | 583篇 |
2007年 | 493篇 |
2006年 | 471篇 |
2005年 | 382篇 |
2004年 | 407篇 |
2003年 | 389篇 |
2002年 | 358篇 |
2001年 | 67篇 |
2000年 | 56篇 |
1999年 | 66篇 |
1998年 | 74篇 |
1997年 | 56篇 |
1996年 | 53篇 |
1995年 | 42篇 |
1994年 | 37篇 |
1993年 | 52篇 |
1992年 | 35篇 |
1991年 | 26篇 |
1990年 | 17篇 |
1989年 | 30篇 |
1988年 | 20篇 |
1987年 | 26篇 |
1986年 | 19篇 |
1985年 | 20篇 |
1984年 | 22篇 |
1983年 | 32篇 |
1982年 | 21篇 |
1981年 | 20篇 |
1980年 | 12篇 |
1978年 | 8篇 |
1977年 | 18篇 |
1976年 | 13篇 |
1975年 | 8篇 |
1974年 | 9篇 |
1973年 | 8篇 |
排序方式: 共有8567条查询结果,搜索用时 531 毫秒
91.
92.
93.
Engineer pioneer plants respond to and affect geomorphic constraints similarly along water–terrestrial interfaces world‐wide 下载免费PDF全文
Dov Corenblit Andreas Baas Thorsten Balke Tjeerd Bouma François Fromard Virginia Garófano‐Gómez Eduardo González Angela M. Gurnell Borbála Hortobágyi Frédéric Julien Daehyun Kim Luc Lambs J. Anthony Stallins Johannes Steiger Eric Tabacchi Romain Walcker 《Global Ecology and Biogeography》2015,24(12):1363-1376
94.
95.
Nadine Kraemer Ethiraj Ravindran Sami Zaqout Gerda Neubert Detlev Schindler Olaf Ninnemann Ralph Gr?f Andrea EM Seiler Angela M Kaindl 《Cell cycle (Georgetown, Tex.)》2015,14(13):2044-2057
Biallelic mutations in the gene encoding centrosomal CDK5RAP2 lead to autosomal recessive primary microcephaly (MCPH), a disorder characterized by pronounced reduction in volume of otherwise architectonical normal brains and intellectual deficit. The current model for the microcephaly phenotype in MCPH invokes a premature shift from symmetric to asymmetric neural progenitor-cell divisions with a subsequent depletion of the progenitor pool. The isolated neural phenotype, despite the ubiquitous expression of CDK5RAP2, and reports of progressive microcephaly in individual MCPH cases prompted us to investigate neural and non-neural differentiation of Cdk5rap2-depleted and control murine embryonic stem cells (mESC). We demonstrate an accumulating proliferation defect of neurally differentiating Cdk5rap2-depleted mESC and cell death of proliferative and early postmitotic cells. A similar effect does not occur in non-neural differentiation into beating cardiomyocytes, which is in line with the lack of non-central nervous system features in MCPH patients. Our data suggest that MCPH is not only caused by premature differentiation of progenitors, but also by reduced propagation and survival of neural progenitors. 相似文献
96.
97.
98.
99.
Ramona Jühlen Jan Idkowiak Angela E. Taylor Barbara Kind Wiebke Arlt Angela Huebner Katrin Koehler 《PloS one》2015,10(4)
Triple A syndrome is caused by mutations in AAAS encoding the protein ALADIN. We investigated the role of ALADIN in the human adrenocortical cell line NCI-H295R1 by either over-expression or down-regulation of ALADIN. Our findings indicate that AAAS knock-down induces a down-regulation of genes coding for type II microsomal cytochrome P450 hydroxylases CYP17A1 and CYP21A2 and their electron donor enzyme cytochrome P450 oxidoreductase, thereby decreasing biosynthesis of precursor metabolites required for glucocorticoid and androgen production. Furthermore we demonstrate that ALADIN deficiency leads to increased susceptibility to oxidative stress and alteration in redox homeostasis after paraquat treatment. Finally, we show significantly impaired nuclear import of DNA ligase 1, aprataxin and ferritin heavy chain 1 in ALADIN knock-down cells. We conclude that down-regulating ALADIN results in decreased oxidative stress response leading to alteration in steroidogenesis, highlighting our knock-down cell model as an important in-vitro tool for studying the adrenal phenotype in triple A syndrome. 相似文献