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   1432514篇
  免费   121694篇
  国内免费   6608篇
耳鼻咽喉   17848篇
儿科学   45433篇
妇产科学   38109篇
基础医学   197209篇
口腔科学   38544篇
临床医学   130578篇
内科学   298239篇
皮肤病学   33515篇
神经病学   121115篇
特种医学   59213篇
外国民族医学   279篇
外科学   223350篇
综合类   32666篇
现状与发展   2篇
一般理论   501篇
预防医学   114495篇
眼科学   29843篇
药学   100384篇
  5篇
中国医学   2346篇
肿瘤学   77142篇
  2018年   15683篇
  2017年   12331篇
  2016年   14795篇
  2015年   16612篇
  2014年   23029篇
  2013年   33894篇
  2012年   42630篇
  2011年   45396篇
  2010年   28179篇
  2009年   27432篇
  2008年   42272篇
  2007年   45111篇
  2006年   45790篇
  2005年   44348篇
  2004年   42302篇
  2003年   40827篇
  2002年   38848篇
  2001年   67505篇
  2000年   69169篇
  1999年   57903篇
  1998年   17889篇
  1997年   15956篇
  1996年   16783篇
  1995年   16978篇
  1994年   15737篇
  1993年   14744篇
  1992年   47937篇
  1991年   46532篇
  1990年   44693篇
  1989年   42541篇
  1988年   39435篇
  1987年   38664篇
  1986年   36486篇
  1985年   35280篇
  1984年   26953篇
  1983年   22589篇
  1982年   14368篇
  1981年   12892篇
  1980年   12103篇
  1979年   23971篇
  1978年   17419篇
  1977年   14714篇
  1976年   13438篇
  1975年   14018篇
  1974年   16375篇
  1973年   15671篇
  1972年   14424篇
  1971年   13237篇
  1970年   12102篇
  1969年   11313篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
1.
Die Anaesthesiologie - Phantomschmerzen haben eine hohe Prävalenz nach Majoramputationen und sind mit einer zusätzlichen Einschränkung der Lebensqualität verbunden....  相似文献   
2.
3.
4.
5.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses...  相似文献   
6.
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.  相似文献   
7.
8.
International Journal of Clinical Oncology - Immune-checkpoint inhibitors (ICIs) are standard treatments for metastatic non-small cell lung cancer (NSCLC). Patients with poor performance status...  相似文献   
9.
10.
Amacrine cells of the retina are conspicuously variable in their morphologies, their population demographics, and their ensuing functions. Vesicular glutamate transporter 3 (VGluT3) amacrine cells are a recently characterized type of amacrine cell exhibiting local dendritic autonomy. The present analysis has examined three features of this VGluT3 population, including their density, local distribution, and dendritic spread, to discern the extent to which these are interrelated, using male and female mice. We first demonstrate that Bax-mediated cell death transforms the mosaic of VGluT3 cells from a random distribution into a regular mosaic. We subsequently examine the relationship between cell density and mosaic regularity across recombinant inbred strains of mice, finding that, although both traits vary across the strains, they exhibit minimal covariation. Other genetic determinants must therefore contribute independently to final cell number and to mosaic order. Using a conditional KO approach, we further demonstrate that Bax acts via the bipolar cell population, rather than cell-intrinsically, to control VGluT3 cell number. Finally, we consider the relationship between the dendritic arbors of single VGluT3 cells and the distribution of their homotypic neighbors. Dendritic field area was found to be independent of Voronoi domain area, while dendritic coverage of single cells was not conserved, simply increasing with the size of the dendritic field. Bax-KO retinas exhibited a threefold increase in dendritic coverage. Each cell, however, contributed less dendrites at each depth within the plexus, intermingling their processes with those of neighboring cells to approximate a constant volumetric density, yielding a uniformity in process coverage across the population.SIGNIFICANCE STATEMENT Different types of retinal neuron spread their processes across the surface of the retina to achieve a degree of dendritic coverage that is characteristic of each type. Many of these types achieve a constant coverage by varying their dendritic field area inversely with the local density of like-type neighbors. Here we report a population of retinal amacrine cells that do not develop dendritic arbors in relation to the spatial positioning of such homotypic neighbors; rather, this cell type modulates the extent of its dendritic branching when faced with a variable number of overlapping dendritic fields to approximate a uniformity in dendritic density across the retina.  相似文献   
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