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   2684673篇
  免费   205743篇
  国内免费   4352篇
耳鼻咽喉   38295篇
儿科学   91853篇
妇产科学   76358篇
基础医学   380943篇
口腔科学   77247篇
临床医学   236553篇
内科学   522292篇
皮肤病学   58382篇
神经病学   212496篇
特种医学   109558篇
外国民族医学   1148篇
外科学   408787篇
综合类   60811篇
现状与发展   4篇
一般理论   867篇
预防医学   209089篇
眼科学   61806篇
药学   200995篇
  7篇
中国医学   4846篇
肿瘤学   142431篇
  2018年   27810篇
  2017年   22468篇
  2016年   23814篇
  2015年   28215篇
  2014年   37083篇
  2013年   54274篇
  2012年   78005篇
  2011年   77880篇
  2010年   45834篇
  2009年   45071篇
  2008年   72609篇
  2007年   77520篇
  2006年   78607篇
  2005年   83671篇
  2004年   83565篇
  2003年   76706篇
  2002年   71153篇
  2001年   122021篇
  2000年   125092篇
  1999年   108497篇
  1998年   29309篇
  1997年   26434篇
  1996年   26721篇
  1995年   25842篇
  1994年   24342篇
  1993年   22774篇
  1992年   89944篇
  1991年   88033篇
  1990年   86462篇
  1989年   82979篇
  1988年   76973篇
  1987年   75868篇
  1986年   71718篇
  1985年   68777篇
  1984年   51375篇
  1983年   43940篇
  1982年   25295篇
  1981年   22653篇
  1979年   48534篇
  1978年   33710篇
  1977年   28262篇
  1976年   26551篇
  1975年   28947篇
  1974年   34966篇
  1973年   33483篇
  1972年   31022篇
  1971年   28933篇
  1970年   26894篇
  1969年   25072篇
  1968年   22917篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
105.
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   
106.
107.
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   
108.
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   
109.
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   
110.
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