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   2149096篇
  免费   165477篇
  国内免费   4338篇
耳鼻咽喉   29229篇
儿科学   65897篇
妇产科学   59064篇
基础医学   305289篇
口腔科学   61457篇
临床医学   190907篇
内科学   425642篇
皮肤病学   48519篇
神经病学   173624篇
特种医学   82726篇
外国民族医学   536篇
外科学   332536篇
综合类   46745篇
现状与发展   4篇
一般理论   678篇
预防医学   159706篇
眼科学   49182篇
药学   157443篇
  4篇
中国医学   4842篇
肿瘤学   124881篇
  2019年   15971篇
  2018年   23027篇
  2017年   17726篇
  2016年   19893篇
  2015年   22423篇
  2014年   31273篇
  2013年   46581篇
  2012年   63197篇
  2011年   66655篇
  2010年   39316篇
  2009年   37764篇
  2008年   63009篇
  2007年   66462篇
  2006年   67548篇
  2005年   65364篇
  2004年   62671篇
  2003年   60048篇
  2002年   58355篇
  2001年   114302篇
  2000年   117246篇
  1999年   97363篇
  1998年   25483篇
  1997年   22796篇
  1996年   22931篇
  1995年   21679篇
  1994年   19789篇
  1993年   18468篇
  1992年   73959篇
  1991年   70765篇
  1990年   68066篇
  1989年   65619篇
  1988年   60088篇
  1987年   58649篇
  1986年   54611篇
  1985年   52321篇
  1984年   38694篇
  1983年   32638篇
  1982年   18639篇
  1981年   16402篇
  1979年   34131篇
  1978年   23515篇
  1977年   19817篇
  1976年   18036篇
  1975年   19018篇
  1974年   23072篇
  1973年   22065篇
  1972年   20774篇
  1971年   19214篇
  1970年   18313篇
  1969年   17079篇
排序方式: 共有10000条查询结果,搜索用时 62 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