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   3749900篇
  免费   311883篇
  国内免费   14603篇
耳鼻咽喉   50625篇
儿科学   119194篇
妇产科学   97586篇
基础医学   588939篇
口腔科学   102091篇
临床医学   338337篇
内科学   668103篇
皮肤病学   98427篇
神经病学   315998篇
特种医学   146704篇
外国民族医学   262篇
外科学   579212篇
综合类   113759篇
现状与发展   23篇
一般理论   2359篇
预防医学   307350篇
眼科学   88663篇
药学   260349篇
  21篇
中国医学   11407篇
肿瘤学   186977篇
  2021年   55505篇
  2020年   35378篇
  2019年   58479篇
  2018年   72707篇
  2017年   55147篇
  2016年   61036篇
  2015年   74739篇
  2014年   108999篇
  2013年   174434篇
  2012年   104368篇
  2011年   106181篇
  2010年   120705篇
  2009年   123638篇
  2008年   92773篇
  2007年   97333篇
  2006年   106829篇
  2005年   101591篇
  2004年   103321篇
  2003年   93253篇
  2002年   82588篇
  2001年   136072篇
  2000年   129615篇
  1999年   122007篇
  1998年   68592篇
  1997年   65266篇
  1996年   62992篇
  1995年   58541篇
  1994年   52527篇
  1993年   48892篇
  1992年   85041篇
  1991年   80955篇
  1990年   76669篇
  1989年   75111篇
  1988年   69014篇
  1987年   67192篇
  1986年   63532篇
  1985年   62763篇
  1984年   54868篇
  1983年   49575篇
  1982年   43616篇
  1981年   40986篇
  1980年   38454篇
  1979年   44723篇
  1978年   37905篇
  1977年   34479篇
  1976年   31589篇
  1975年   30468篇
  1974年   32244篇
  1973年   30983篇
  1972年   28942篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
Immunoglobulin light chain amyloidosis (AL) commonly presents with nephrotic range proteinuria, heart failure with preserved ejection fraction, nondiabetic peripheral neuropathy, unexplained hepatomegaly or diarrhea, and should be considered in patients presenting with these symptoms. More importantly, patients being monitored for smoldering multiple myeloma and a monoclonal gammopathy of undetermined significance (MGUS) are at risk for developing AL amyloidosis. MGUS and myeloma patients that have atypical features, including unexplained weight loss; lower extremity edema, early satiety, and dyspnea on exertion should be considered at risk for light chain amyloidosis. Overlooking the diagnosis of light chain amyloidosis leading to therapy delay is common, and it represents an error of diagnostic consideration. Herein we provide a review of established and investigational treatments for patients with AL amyloidosis and provide algorithms for workup and management of these patients.Subject terms: Myeloma, Chemotherapy  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