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   2224521篇
  免费   170728篇
  国内免费   4486篇
耳鼻咽喉   29928篇
儿科学   68110篇
妇产科学   60706篇
基础医学   316802篇
口腔科学   63712篇
临床医学   197581篇
内科学   440160篇
皮肤病学   49634篇
神经病学   181192篇
特种医学   85719篇
外国民族医学   545篇
外科学   341712篇
综合类   47063篇
现状与发展   5篇
一般理论   756篇
预防医学   168964篇
眼科学   50415篇
药学   162212篇
  4篇
中国医学   5004篇
肿瘤学   129511篇
  2019年   17216篇
  2018年   24545篇
  2017年   19023篇
  2016年   21332篇
  2015年   24046篇
  2014年   33514篇
  2013年   49478篇
  2012年   67831篇
  2011年   71237篇
  2010年   41780篇
  2009年   40272篇
  2008年   67105篇
  2007年   70624篇
  2006年   71575篇
  2005年   69146篇
  2004年   65895篇
  2003年   63107篇
  2002年   61153篇
  2001年   116458篇
  2000年   119414篇
  1999年   99386篇
  1998年   26450篇
  1997年   23578篇
  1996年   23721篇
  1995年   22319篇
  1994年   20410篇
  1993年   19009篇
  1992年   75429篇
  1991年   72096篇
  1990年   69342篇
  1989年   66838篇
  1988年   61222篇
  1987年   59598篇
  1986年   55525篇
  1985年   53210篇
  1984年   39367篇
  1983年   33230篇
  1982年   18960篇
  1981年   16703篇
  1979年   34693篇
  1978年   23865篇
  1977年   20110篇
  1976年   18274篇
  1975年   19265篇
  1974年   23375篇
  1973年   22376篇
  1972年   21031篇
  1971年   19480篇
  1970年   18525篇
  1969年   17282篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
2.
3.

The exercise pressor reflex is a feedback mechanism engaged upon stimulation of mechano- and metabosensitive skeletal muscle afferents. Activation of these afferents elicits a reflex increase in heart rate, blood pressure, and ventilation in an intensity-dependent manner. Consequently, the exercise pressor reflex has been postulated to be one of the principal mediators of the cardiorespiratory responses to exercise. In this updated review, we will discuss classical and recent advancements in our understating of the exercise pressor reflex function in both human and animal models. Particular attention will be paid to the afferent mechanisms and pathways involved during its activation, its effects on different target organs, its potential role in the abnormal cardiovascular response to exercise in diseased states, and the impact of age and biological sex on these responses. Finally, we will highlight some unanswered questions in the literature that may inspire future investigations in the field.

  相似文献   
4.
The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19.  相似文献   
5.
6.
7.
8.
9.
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   
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