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   2589938篇
  免费   184620篇
  国内免费   7562篇
耳鼻咽喉   34285篇
儿科学   85316篇
妇产科学   71617篇
基础医学   363730篇
口腔科学   69699篇
临床医学   234580篇
内科学   515897篇
皮肤病学   62483篇
神经病学   213612篇
特种医学   99908篇
外国民族医学   736篇
外科学   386967篇
综合类   50474篇
现状与发展   5篇
一般理论   968篇
预防医学   196254篇
眼科学   56770篇
药学   188069篇
  8篇
中国医学   5350篇
肿瘤学   145392篇
  2021年   20047篇
  2019年   20664篇
  2018年   29349篇
  2017年   22635篇
  2016年   26287篇
  2015年   29549篇
  2014年   40507篇
  2013年   60531篇
  2012年   80395篇
  2011年   84620篇
  2010年   51093篇
  2009年   49201篇
  2008年   79126篇
  2007年   83953篇
  2006年   85656篇
  2005年   81822篇
  2004年   78816篇
  2003年   76128篇
  2002年   73392篇
  2001年   128478篇
  2000年   131381篇
  1999年   110550篇
  1998年   31279篇
  1997年   27946篇
  1996年   28234篇
  1995年   27398篇
  1994年   25076篇
  1993年   23424篇
  1992年   85181篇
  1991年   81590篇
  1990年   78798篇
  1989年   76083篇
  1988年   69484篇
  1987年   68005篇
  1986年   63552篇
  1985年   60525篇
  1984年   44947篇
  1983年   37953篇
  1982年   22462篇
  1981年   19989篇
  1979年   38965篇
  1978年   27444篇
  1977年   23255篇
  1976年   21499篇
  1975年   22817篇
  1974年   26791篇
  1973年   25373篇
  1972年   23755篇
  1971年   21960篇
  1970年   20184篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Platelet transfusions are a life-saving medical intervention used for the treatment of thrombocytopenia or hemorrhage. Extensive research has gone into trying to understand how to store platelets prior to the transfusion event. Much has been learned about storage bag materials, synthetic solutions, and how temperature impacts platelet viability and function. While room temperature storage of platelets preserves 24-hour in vivo platelet recovery and survival there is a greater risk for bacterial growth. Therefore, cold storage of platelets has become attractive due to the reduction in potential bacterial proliferation and the maintenance of platelet function beyond 5 days of storage. Cold stored platelets, however, have their own set of challenges. Cold stored platelets become activated through several mechanisms. The morphological and molecular changes that occur due to cold exposure enhance their ability to participate in the hemostatic process at the cost of rapid clearance from circulation. This review focuses on the underlying mechanisms leading to cold platelet activation and the receptor modifications involved in platelet clearance.  相似文献   
82.
European Journal of Orthopaedic Surgery & Traumatology - The goals of this study were to compare patient satisfaction and wound-related complications in patients receiving 2-octyl cyanoacrylate...  相似文献   
83.
84.
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   
85.
86.
87.
88.
89.
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   
90.
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