首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7109篇
  免费   569篇
  国内免费   321篇
  2023年   95篇
  2022年   101篇
  2021年   184篇
  2020年   193篇
  2019年   260篇
  2018年   271篇
  2017年   191篇
  2016年   222篇
  2015年   266篇
  2014年   484篇
  2013年   541篇
  2012年   386篇
  2011年   469篇
  2010年   379篇
  2009年   435篇
  2008年   456篇
  2007年   418篇
  2006年   336篇
  2005年   316篇
  2004年   227篇
  2003年   255篇
  2002年   206篇
  2001年   113篇
  2000年   99篇
  1999年   81篇
  1998年   87篇
  1997年   65篇
  1996年   53篇
  1995年   46篇
  1994年   39篇
  1993年   28篇
  1992年   33篇
  1991年   24篇
  1990年   22篇
  1989年   15篇
  1988年   29篇
  1986年   15篇
  1985年   42篇
  1984年   59篇
  1983年   65篇
  1982年   62篇
  1981年   45篇
  1980年   52篇
  1979年   45篇
  1978年   41篇
  1977年   39篇
  1976年   29篇
  1975年   26篇
  1974年   23篇
  1973年   12篇
排序方式: 共有7999条查询结果,搜索用时 15 毫秒
1.
From three Fouquieria sp. 12 iridoid glucosides were isolated and identified. Eight of these were structurally related to galioside (monotropein methylester), while four were hydroxy substitution products of deoxyloganin. In three cases the glucoside occurred together with the corresponding 10-O-acetate.  相似文献   
2.
《Developmental cell》2021,56(21):2995-3005.e4
  1. Download : Download high-res image (168KB)
  2. Download : Download full-size image
  相似文献   
3.
Spindly is a dynein adaptor involved in chromosomal segregation during cell division. While Spindly's N-terminal domain binds to the microtubule motor dynein and its activator dynactin, the C-terminal domain (Spindly-C) binds its cargo, the ROD/ZW10/ZWILCH (RZZ) complex in the outermost layer of the kinetochore. In humans, Spindly-C binds to ROD, while in C. elegans Spindly-C binds to both Zwilch (ZWL-1) and ROD-1. Here, we employed various biophysical techniques to characterize the structure, dynamics and interaction sites of C. elegans Spindly-C. We found that despite the overall disorder, there are two regions with variable α-helical propensity. One of these regions is located in the C-terminal half and is compact; the second is sparsely populated in the N-terminal half. The interactions with both ROD-1 and ZWL-1 are mostly mediated by the same two sequentially remote disordered segments of Spindly-C, which are C-terminally adjacent to the helical regions. The findings suggest that the Spindly-C binding sites on ROD-1 in the ROD-1/ZWL-1 complex context are either shielded or conformationally weakened by the presence of ZWL-1 such that only ZWL-1 directly interacts with Spindly-C in C. elegans  相似文献   
4.
《Cytokine》2015,73(2):224-225
Balanced regulation of cytokine secretion in T cells is critical for maintenance of immune homeostasis and prevention of autoimmunity. The Rho-associated kinase (ROCK) 2 signaling pathway was previously shown to be involved in controlling of cellular movement and shape. However, recent work from our group and others has demonstrated a new and important role of ROCK2 in regulating cytokine secretion in T cells. We found that ROCK2 promotes pro-inflammatory cytokines such as IL-17 and IL-21, whereas IL-2 and IL-10 secretion are negatively regulated by ROCK2 under Th17-skewing activation. Also, in disease, but not in steady state conditions, ROCK2 contributes to regulation of IFN-γ secretion in T cells from rheumatoid arthritis patients. Thus, ROCK2 signaling is a key pathway in modulation of T-cell mediated immune responses underscoring the therapeutic potential of targeted inhibition of ROCK2 in autoimmunity.  相似文献   
5.
6.
7.
Flow cytometry: rapid biochemical analysis of single cells   总被引:7,自引:0,他引:7  
  相似文献   
8.
The aim of this study was to investigate the effect of static magnetic fields (SMF) on reactive oxygen species induced by X‐ray radiation. The experiments were performed on lymphocytes from male albino Wistar rats. After exposure to 3 Gy X‐ray radiation (with a dose rate of 560 mGy/min) the measurement of intracellular reactive oxygen species in lymphocytes, using a fluorescent probe, was done before exposure to the SMF, and after 15 min, 1 and 2 h of exposure to the SMF or a corresponding incubation time. For SMF exposure, 0 mT (50 µT magnetic field induction opposite to the geomagnetic field) and 5 mT fields were chosen. The trend of SMF effects for 0 mT was always opposite that of 5 mT. The first one decreased the rate of fluorescence change, while the latter one increased it. Bioelectromagnetics 34:333–336, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
9.
《Molecular cell》2020,77(6):1176-1192.e16
  1. Download : Download high-res image (173KB)
  2. Download : Download full-size image
  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号