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   1865467篇
  免费   141391篇
  国内免费   3218篇
耳鼻咽喉   25692篇
儿科学   62253篇
妇产科学   53474篇
基础医学   262913篇
口腔科学   55870篇
临床医学   160252篇
内科学   367788篇
皮肤病学   41504篇
神经病学   147837篇
特种医学   75895篇
外国民族医学   567篇
外科学   281137篇
综合类   41220篇
现状与发展   3篇
一般理论   580篇
预防医学   147365篇
眼科学   42648篇
药学   139563篇
  5篇
中国医学   3563篇
肿瘤学   99947篇
  2018年   22161篇
  2017年   17643篇
  2016年   17973篇
  2015年   21646篇
  2014年   27155篇
  2013年   38594篇
  2012年   58730篇
  2011年   57136篇
  2010年   32352篇
  2009年   31406篇
  2008年   51343篇
  2007年   54575篇
  2006年   55033篇
  2005年   61023篇
  2004年   61006篇
  2003年   54565篇
  2002年   49074篇
  2001年   81371篇
  2000年   82584篇
  1999年   72741篇
  1998年   18539篇
  1997年   16795篇
  1996年   16810篇
  1995年   16507篇
  1994年   15453篇
  1992年   61395篇
  1991年   59915篇
  1990年   58908篇
  1989年   56745篇
  1988年   52778篇
  1987年   51978篇
  1986年   49515篇
  1985年   47432篇
  1984年   35189篇
  1983年   30150篇
  1982年   17027篇
  1981年   15158篇
  1979年   33872篇
  1978年   23174篇
  1977年   19359篇
  1976年   18138篇
  1975年   19849篇
  1974年   24342篇
  1973年   23260篇
  1972年   21434篇
  1971年   20383篇
  1970年   18754篇
  1969年   17646篇
  1968年   16107篇
  1967年   14728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.
Hailey–Hailey disease (HHD), also known as benign familial pemphigus, is an autosomal dominant skin condition that affects the adhesion of epidermal keratinocytes. Although the initial manifestation of flaccid vesicles on erythematous or normal skin in flexure sites frequently goes unnoticed, large, macerated, exudative plaques of superficial erosions with crusting are observed at the time of diagnosis. There is no specific treatment for HHD, and most cases are symptomatically supported. However, infrared laser ablation has been somewhat helpful. We present a case successfully treated with fractional CO2 laser showing a long-term favourable outcome and no adverse effects. Thus, this modality could be an alternative to full ablation for this condition.  相似文献   
76.
77.
78.
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   
79.
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   
80.
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