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   1746750篇
  免费   141675篇
  国内免费   2723篇
耳鼻咽喉   23840篇
儿科学   57805篇
妇产科学   49666篇
基础医学   249640篇
口腔科学   52387篇
临床医学   153749篇
内科学   341937篇
皮肤病学   37912篇
神经病学   144641篇
特种医学   70674篇
外国民族医学   485篇
外科学   265147篇
综合类   40357篇
现状与发展   4篇
一般理论   637篇
预防医学   133049篇
眼科学   39603篇
药学   131064篇
  3篇
中国医学   3164篇
肿瘤学   95384篇
  2018年   17936篇
  2017年   14354篇
  2016年   16321篇
  2015年   18121篇
  2014年   24201篇
  2013年   37296篇
  2012年   50555篇
  2011年   53514篇
  2010年   31214篇
  2009年   28977篇
  2008年   51488篇
  2007年   54200篇
  2006年   54705篇
  2005年   53120篇
  2004年   51865篇
  2003年   49890篇
  2002年   48737篇
  2001年   80406篇
  2000年   84022篇
  1999年   69973篇
  1998年   19266篇
  1997年   17585篇
  1996年   17405篇
  1995年   16906篇
  1994年   15921篇
  1993年   15069篇
  1992年   56696篇
  1991年   54914篇
  1990年   53643篇
  1989年   51872篇
  1988年   48188篇
  1987年   47534篇
  1986年   45165篇
  1985年   43854篇
  1984年   32879篇
  1983年   28269篇
  1982年   16765篇
  1981年   15019篇
  1979年   31094篇
  1978年   21554篇
  1977年   18271篇
  1976年   17128篇
  1975年   18051篇
  1974年   21944篇
  1973年   21072篇
  1972年   19244篇
  1971年   18134篇
  1970年   16620篇
  1969年   15569篇
  1968年   14249篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
To evaluate the changes in alveolar contour after guided bone regeneration (GBR) with two different combinations of biomaterials in dehiscence defects arou  相似文献   
75.
76.
77.
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   
78.
Reactive lymphoid infiltrates of the skin composed predominantly of gamma‐delta (γδ) T cells are not well described in the literature. Herein we report a case of an otherwise healthy 4‐year‐old male who presented with a waxing and waning papular rash characterized by small, discrete crusted papules spread across his trunk, face and extremities. Clinical evaluation revealed no evidence of systemic disease. Microscopic examination revealed a dermal, perivascular infiltrate of highly atypical lymphocytes with a γδ T cell phenotype, worrisome for primary cutaneous γδ T cell lymphoma. The clinical course, however, was that of a reactive condition and prompted consideration of a diagnosis of pityriasis lichenoides et varioliformis acuta (PLEVA) and lymphomatoid papulosis (LyP). In many ways, this case defies current classification schemes and seems to expand the spectrum of reactive γδ T cell infiltrates of the skin.  相似文献   
79.
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   
80.
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