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   4072647篇
  免费   300921篇
  国内免费   10198篇
耳鼻咽喉   57472篇
儿科学   130350篇
妇产科学   111124篇
基础医学   568453篇
口腔科学   116927篇
临床医学   375152篇
内科学   789264篇
皮肤病学   91239篇
神经病学   338033篇
特种医学   158551篇
外国民族医学   1438篇
外科学   610003篇
综合类   91176篇
现状与发展   6篇
一般理论   1720篇
预防医学   325255篇
眼科学   94694篇
药学   301239篇
  11篇
中国医学   7981篇
肿瘤学   213678篇
  2018年   43661篇
  2017年   33584篇
  2016年   38157篇
  2015年   43064篇
  2014年   60631篇
  2013年   92056篇
  2012年   122329篇
  2011年   129811篇
  2010年   77837篇
  2009年   74427篇
  2008年   121824篇
  2007年   129404篇
  2006年   131158篇
  2005年   126802篇
  2004年   122198篇
  2003年   117811篇
  2002年   114655篇
  2001年   187046篇
  2000年   192537篇
  1999年   163294篇
  1998年   48484篇
  1997年   43267篇
  1996年   42903篇
  1995年   41618篇
  1994年   38635篇
  1993年   36149篇
  1992年   129758篇
  1991年   125527篇
  1990年   121335篇
  1989年   117246篇
  1988年   108366篇
  1987年   106745篇
  1986年   100819篇
  1985年   96581篇
  1984年   72642篇
  1983年   62032篇
  1982年   37354篇
  1981年   33615篇
  1979年   66747篇
  1978年   47233篇
  1977年   40022篇
  1976年   37492篇
  1975年   39594篇
  1974年   47990篇
  1973年   45810篇
  1972年   43106篇
  1971年   39923篇
  1970年   37306篇
  1969年   35274篇
  1968年   32451篇
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
121.
122.
123.
124.
125.
126.
127.
128.
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   
129.
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   
130.
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