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   1542954篇
  免费   124061篇
  国内免费   6896篇
耳鼻咽喉   19941篇
儿科学   49370篇
妇产科学   42128篇
基础医学   212698篇
口腔科学   43323篇
临床医学   134110篇
内科学   324694篇
皮肤病学   38583篇
神经病学   127546篇
特种医学   60280篇
外国民族医学   305篇
外科学   235735篇
综合类   32585篇
现状与发展   2篇
一般理论   467篇
预防医学   127871篇
眼科学   32616篇
药学   109092篇
  5篇
中国医学   3033篇
肿瘤学   79527篇
  2021年   12861篇
  2019年   13498篇
  2018年   19895篇
  2017年   14715篇
  2016年   16786篇
  2015年   18699篇
  2014年   25587篇
  2013年   38276篇
  2012年   49713篇
  2011年   52944篇
  2010年   31899篇
  2009年   29927篇
  2008年   47851篇
  2007年   50986篇
  2006年   51501篇
  2005年   49917篇
  2004年   47296篇
  2003年   45703篇
  2002年   43284篇
  2001年   72106篇
  2000年   74350篇
  1999年   61861篇
  1998年   18061篇
  1997年   15997篇
  1996年   16922篇
  1995年   16999篇
  1994年   15673篇
  1993年   14622篇
  1992年   49628篇
  1991年   48153篇
  1990年   46148篇
  1989年   43718篇
  1988年   40484篇
  1987年   39796篇
  1986年   37519篇
  1985年   36153篇
  1984年   27484篇
  1983年   23037篇
  1982年   14346篇
  1981年   12876篇
  1979年   24637篇
  1978年   17758篇
  1977年   14957篇
  1976年   13786篇
  1975年   14496篇
  1974年   17093篇
  1973年   16416篇
  1972年   15057篇
  1971年   13856篇
  1970年   12758篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Molnár  B.  Aroca  S.  Dobos  A.  Orbán  K.  Szabó  J.  Windisch  P.  Stähli  A.  Sculean  A. 《Clinical oral investigations》2022,26(12):7135-7142
Clinical Oral Investigations - To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with...  相似文献   
2.
Die Anaesthesiologie - Phantomschmerzen haben eine hohe Prävalenz nach Majoramputationen und sind mit einer zusätzlichen Einschränkung der Lebensqualität verbunden....  相似文献   
3.
4.
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   
5.
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   
6.
7.
8.
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   
9.
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