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   3137781篇
  免费   267199篇
  国内免费   13752篇
耳鼻咽喉   43454篇
儿科学   99108篇
妇产科学   78877篇
基础医学   510444篇
口腔科学   85725篇
临床医学   279683篇
内科学   551331篇
皮肤病学   88416篇
神经病学   267236篇
特种医学   120816篇
外国民族医学   102篇
外科学   487761篇
综合类   94903篇
现状与发展   23篇
一般理论   2149篇
预防医学   265808篇
眼科学   71871篇
药学   213995篇
  20篇
中国医学   10427篇
肿瘤学   146583篇
  2021年   57237篇
  2020年   36144篇
  2019年   60087篇
  2018年   73493篇
  2017年   55204篇
  2016年   60453篇
  2015年   74956篇
  2014年   109752篇
  2013年   175642篇
  2012年   89300篇
  2011年   89004篇
  2010年   117732篇
  2009年   121383篇
  2008年   73935篇
  2007年   76254篇
  2006年   86674篇
  2005年   81835篇
  2004年   83279篇
  2003年   73912篇
  2002年   63684篇
  2001年   88835篇
  2000年   81362篇
  1999年   83762篇
  1998年   63454篇
  1997年   61550篇
  1996年   59161篇
  1995年   54682篇
  1994年   48838篇
  1993年   45576篇
  1992年   55609篇
  1991年   53248篇
  1990年   50232篇
  1989年   50231篇
  1988年   46378篇
  1987年   45086篇
  1986年   42926篇
  1985年   43352篇
  1984年   41447篇
  1983年   38485篇
  1982年   39044篇
  1981年   37073篇
  1980年   35077篇
  1979年   33218篇
  1978年   30994篇
  1977年   28798篇
  1976年   26475篇
  1975年   25148篇
  1974年   24966篇
  1973年   23860篇
  1972年   22291篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
41.
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   
42.
43.
Fibroblast growth factor receptors (FGFRs) are aberrantly activated through single-nucleotide variants, gene fusions and copy number amplifications in 5–10% of all human cancers, although this frequency increases to 10–30% in urothelial carcinoma and intrahepatic cholangiocarcinoma. We begin this review by highlighting the diversity of FGFR genomic alterations identified in human cancers and the current challenges associated with the development of clinical-grade molecular diagnostic tests to accurately detect these alterations in the tissue and blood of patients. The past decade has seen significant advancements in the development of FGFR-targeted therapies, which include selective, non-selective and covalent small-molecule inhibitors, as well as monoclonal antibodies against the receptors. We describe the expanding landscape of anti-FGFR therapies that are being assessed in early phase and randomised controlled clinical trials, such as erdafitinib and pemigatinib, which are approved by the Food and Drug Administration for the treatment of FGFR3-mutated urothelial carcinoma and FGFR2-fusion cholangiocarcinoma, respectively. However, despite initial sensitivity to FGFR inhibition, acquired drug resistance leading to cancer progression develops in most patients. This phenomenon underscores the need to clearly delineate tumour-intrinsic and tumour-extrinsic mechanisms of resistance to facilitate the development of second-generation FGFR inhibitors and novel treatment strategies beyond progression on targeted therapy.Subject terms: Cancer, Cancer  相似文献   
44.
45.
46.
47.
48.
49.
50.
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