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   7184篇
  免费   826篇
  国内免费   21篇
耳鼻咽喉   88篇
儿科学   254篇
妇产科学   175篇
基础医学   876篇
口腔科学   229篇
临床医学   701篇
内科学   1536篇
皮肤病学   230篇
神经病学   397篇
特种医学   468篇
外科学   1096篇
综合类   245篇
一般理论   4篇
预防医学   631篇
眼科学   161篇
药学   354篇
  1篇
中国医学   2篇
肿瘤学   583篇
  2021年   80篇
  2019年   93篇
  2018年   75篇
  2017年   65篇
  2016年   79篇
  2015年   115篇
  2014年   155篇
  2013年   239篇
  2012年   297篇
  2011年   264篇
  2010年   212篇
  2009年   202篇
  2008年   268篇
  2007年   287篇
  2006年   267篇
  2005年   307篇
  2004年   273篇
  2003年   286篇
  2002年   227篇
  2001年   184篇
  2000年   186篇
  1999年   190篇
  1998年   165篇
  1997年   151篇
  1996年   133篇
  1995年   124篇
  1994年   98篇
  1993年   107篇
  1992年   157篇
  1991年   145篇
  1990年   128篇
  1989年   148篇
  1988年   164篇
  1987年   117篇
  1986年   108篇
  1985年   98篇
  1984年   94篇
  1983年   120篇
  1982年   99篇
  1981年   78篇
  1980年   89篇
  1979年   88篇
  1978年   85篇
  1977年   77篇
  1976年   97篇
  1975年   79篇
  1974年   64篇
  1973年   66篇
  1971年   70篇
  1970年   57篇
排序方式: 共有8031条查询结果,搜索用时 10 毫秒
1.
2.
3.
The vasomotor response of native human collateral vessels to pharmacologic or hemodynamic vasodilatory stimuli is not well known. We describe a case where retrograde collateral flow velocity was measured both at baseline and following selected hemodynamic and pharmacologic interventions. This index case represents the first in a series of potential human physiologic studies designed to address questions pertaining to control of collateral blood supply in humans. © 1993 Wiley-Liss, Inc.  相似文献   
4.
Fine Needle Aspiration Cytology (F.N.A.C.) has been used as a diagnostic tool by the ENT departments in Tayside since the end of 1985. This paper discusses the results of our initial experience with this and outlines some of the diagnostic pitfalls. This is a useful and accurate procedure with many advantages over diagnostic biopsy.  相似文献   
5.
The present studies were undertaken to determine the involvement of neurons in the hypothalamic paraventricular nucleus (PVN) in stress-induced renin secretion. The stressor was a 10-min conditioned emotional response (CER) paradigm. Bilateral electrolytic lesions in the PVN prevented the stress-induced increase in plasma renin activity (PRA), and plasma renin concentration (PRC). Stress-induced corticosterone secretion was also blocked, supporting the histological verification and suggesting that the lesion included corticosterone-releasing factor neurons in the PVN. Stress-induced renin secretion appears to be restricted to the PVN, as electrolytic lesions in the nucleus reuniens, dorsal and caudal to the PVN, did not prevent the stress-induced increase in either PRA or PRC. The next step was to determine whether cell bodies in the PVN or fibers of passage through the PVN mediate the stress-induced increase of these hormones. For this purpose, bilateral stereotaxic injections of the cell-selective neurotoxin ibotenic acid (10 micrograms/microliter; 0.3 microliters per side) were performed 14 days prior to the stress procedure. Histological evaluation of the tissue revealed cell death and lysis in the PVN. Ibotenic acid injection into the PVN prevented the effect of stress on PRA, PRC and corticosterone levels. None of the lesions prevented the stress-induced rise in plasma prolactin concentration. These results suggest that neurons in the PVN play an important role in mediating stress-induced increases in renin and corticosterone but not prolactin secretion.  相似文献   
6.
7.
8.
9.
10.
Risk Factors for a First Febrile Seizure: A Matched Case-Control Study   总被引:10,自引:6,他引:4  
Summary We conducted a matched casecontrol study to identify risk factors for first febrile seizures, with special emphasis on characteristics of the acute illness episode. Cases were identified through hospital emergency departments; controls were identified through outpatient clinics and emergency departments. Sixtynine children with first febrile seizures and no history of previous unprovoked seizures were matched for age (±6 months), site of routine pediatric care, and date of visit (±weeks) with 1 or 2 febrile controls who had no history of previous febrile or unprovoked seizures. Medical records for the index visit were reviewed, and parents were interviewed by telephone. Illness characteristics examined included height of temperature, type of underlying illness, contact with a physician during the illness but before the index visit, and use of acetaminophen or decongestants. Family history of febrile and of unprovoked seizures, sociodemographic characteristics, daycare use, and selected preand perinatal variables were also studied. On multivariable analysis, significant independent risk factors were height of temperature, history of febrile seizures in a firstor in a higher degree relative. Gastroenteritis as the underlying illness had a significant inverse (i.e., protective) association with febrile seizures. Maternal smoking during pregnancy was a marginally significant predictor of febrile seizures.  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