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   3778篇
  免费   247篇
  国内免费   23篇
耳鼻咽喉   15篇
儿科学   228篇
妇产科学   69篇
基础医学   467篇
口腔科学   115篇
临床医学   373篇
内科学   881篇
皮肤病学   62篇
神经病学   211篇
特种医学   530篇
外科学   300篇
综合类   40篇
一般理论   1篇
预防医学   239篇
眼科学   38篇
药学   210篇
中国医学   10篇
肿瘤学   259篇
  2022年   20篇
  2021年   71篇
  2020年   38篇
  2019年   73篇
  2018年   89篇
  2017年   57篇
  2016年   62篇
  2015年   78篇
  2014年   101篇
  2013年   158篇
  2012年   122篇
  2011年   132篇
  2010年   135篇
  2009年   118篇
  2008年   156篇
  2007年   132篇
  2006年   137篇
  2005年   129篇
  2004年   102篇
  2003年   103篇
  2002年   82篇
  2001年   79篇
  2000年   96篇
  1999年   86篇
  1998年   155篇
  1997年   129篇
  1996年   149篇
  1995年   102篇
  1994年   86篇
  1993年   92篇
  1992年   46篇
  1991年   62篇
  1990年   40篇
  1989年   91篇
  1988年   73篇
  1987年   79篇
  1986年   78篇
  1985年   72篇
  1984年   42篇
  1983年   48篇
  1982年   42篇
  1981年   29篇
  1980年   47篇
  1979年   25篇
  1978年   24篇
  1977年   23篇
  1976年   32篇
  1975年   27篇
  1966年   11篇
  1965年   11篇
排序方式: 共有4048条查询结果,搜索用时 35 毫秒
91.
Endomyocardial fibrosis is a restrictive cardiomyopathy of unknown etiology prevalent in tropical regions. It is characterized by fibrotic obliteration of the apex of one or both ventricles, which can be extended to the ventricular inlet chamber. It predominantly affects children and young adults. There is no specific treatment and usually has a poor prognosis. It is uncommon in Spain, but due to immigration, it appears to be increasing. Four cases of endomyocardial fibrosis in children diagnosed and treated in Spain are presented, as a well as a review of this disease.  相似文献   
92.
93.
94.
Populations of the common bed bug, Cimex lectularius, have recently undergone explosive growth. Bed bugs share many important traits with triatomine insects, but it remains unclear whether these similarities include the ability to transmit Trypanosoma cruzi, the etiologic agent of Chagas disease. Here, we show efficient and bidirectional transmission of T. cruzi between hosts and bed bugs in a laboratory environment. Most bed bugs that fed on experimentally infected mice acquired the parasite. A majority of previously uninfected mice became infected after a period of cohabitation with exposed bed bugs. T. cruzi was also transmitted to mice after the feces of infected bed bugs were applied directly to broken host skin. Quantitative bed bug defecation measures were similar to those of important triatomine vectors. Our findings suggest that the common bed bug may be a competent vector of T. cruzi and could pose a risk for vector-borne transmission of Chagas disease.  相似文献   
95.
Sleep loss increases blood–brain barrier permeability. As the blood–brain barrier and the blood–tissue barriers in the reproductive tract (blood–testis and blood–epididymis barriers) share common characteristics, we hypothesized that sleep restriction may also modify their barrier function. Previous reports showed that sleep loss decreased sperm viability and progressive fast mobility, which may be a consequence of altered blood–testis and blood–epididymis barrier. Therefore, we quantified changes in blood–testis and blood–epididymis barrier after sleep loss and related them to male fertility. Adult male Wistar rats were sleep restricted using the multiple‐platform technique in a protocol of 20 hr daily sleep deprivation plus 4 hr of sleep recovery in the home‐cage. At the 10th day, barrier permeability assays were performed with Na‐fluorescein, 10 kDa Cascade blue‐dextrans and Evans blue, and the expression of tight junction proteins, actin and androgen receptor was quantified. At the 10th day of sleep restriction and after sleep recovery days 1–7, males were placed with sexually receptive females, sexual behaviour was tested, and the percentage of pregnancies was calculated. Sleep restriction increased the barrier permeability to low‐ and high‐molecular‐weight tracers, and decreased the expression of tight junction proteins, actin and androgen receptor. Concomitantly, sleep restriction reduced the percentage of ejaculating males and the number of pregnancies. Sleep recovery for 2–3 days progressively re‐established fertility, as indicated by a higher percentage of ejaculating males and impregnated females. In conclusion, chronic sleep loss alters fertility concomitantly with the disruption of the blood–tissue barriers at the reproductive tract, the mechanism involves androgen signalling.  相似文献   
96.
The elbow joint is a complex joint, which, when impaired in function, leads to severe disability. In some cases however, an arthroplasty might be an appropriate treatment. In the past four decades, large steps havebeen taken to optimize this treatment in order to achieve better post-operative outcomes. To understand these progresses and to discover aspects for upcoming improvements, we present a review on the past developments, the present state of affairs and future developments which may improve patient care further.  相似文献   
97.
98.
99.
100.
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