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   3362520篇
  免费   241116篇
  国内免费   8543篇
耳鼻咽喉   46472篇
儿科学   112321篇
妇产科学   93095篇
基础医学   472463篇
口腔科学   92436篇
临床医学   304953篇
内科学   660487篇
皮肤病学   78481篇
神经病学   273023篇
特种医学   130202篇
外国民族医学   1282篇
外科学   505579篇
综合类   69790篇
现状与发展   6篇
一般理论   1221篇
预防医学   257653篇
眼科学   75873篇
药学   247514篇
  9篇
中国医学   6787篇
肿瘤学   182532篇
  2019年   25893篇
  2018年   36600篇
  2017年   28018篇
  2016年   32188篇
  2015年   36277篇
  2014年   50025篇
  2013年   75561篇
  2012年   101080篇
  2011年   107132篇
  2010年   64630篇
  2009年   61797篇
  2008年   100566篇
  2007年   107061篇
  2006年   108586篇
  2005年   104534篇
  2004年   101140篇
  2003年   97691篇
  2002年   94602篇
  2001年   161240篇
  2000年   165698篇
  1999年   140207篇
  1998年   40210篇
  1997年   35786篇
  1996年   35982篇
  1995年   34705篇
  1994年   32156篇
  1993年   30136篇
  1992年   110095篇
  1991年   106354篇
  1990年   103301篇
  1989年   99743篇
  1988年   91538篇
  1987年   89833篇
  1986年   84048篇
  1985年   80312篇
  1984年   60046篇
  1983年   50847篇
  1982年   29911篇
  1981年   26994篇
  1979年   53337篇
  1978年   37492篇
  1977年   31973篇
  1976年   29655篇
  1975年   31694篇
  1974年   37326篇
  1973年   35575篇
  1972年   33273篇
  1971年   30667篇
  1970年   28573篇
  1969年   26934篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
ABSTRACT

Purpose

To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR).  相似文献   
103.
104.
105.
106.
107.
108.
Advancement in microelectromechanical system has facilitated the microfabrication of polymeric substrates and the development of the novel class of controlled drug delivery devices. These vehicles have specifically tailored three dimensional physical and chemical features which together, provide the capacity to target cell, stimulate unidirectional controlled release of therapeutics and augment permeation across the barriers. Apart from drug delivery devices microfabrication technology’s offer exciting prospects to generate biomimetic gastrointestinal tract models. BioMEMS are capable of analysing biochemical liquid sample like solution of metabolites, macromolecules, proteins, nucleic acid, cells and viruses. This review summarized multidisciplinary application of biomedical microelectromechanical systems in drug delivery and its potential in analytical procedures.  相似文献   
109.
Children who expect they can bring about good outcomes and avoid bad outcomes tend to experience more personal successes. Little is known about factors that contribute to these ‘control expectancies’. The purpose of the present study was to determine whether children's internal control expectancies occur in the context of parents’ internal control expectancies, low family strain, and high family cohesiveness and whether these factors are more strongly related to daughters’ than sons’ control expectancies. A community sample of 85 children aged 9–11 years and their parents (85 mothers; 63 fathers) completed rating scales. Fathers’ more internal control expectancies and mothers’ reports of fewer family strains were associated with daughters’ but not sons’ greater internal control expectancies, and greater family cohesiveness was related to both daughters’ and sons’ internal control orientations. These findings suggest that family factors may contribute to children's, particularly daughters’, development of internal control expectancies.  相似文献   
110.
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  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