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   899535篇
  免费   62445篇
  国内免费   2334篇
耳鼻咽喉   12474篇
儿科学   28676篇
妇产科学   26143篇
基础医学   126575篇
口腔科学   24686篇
临床医学   74750篇
内科学   183137篇
皮肤病学   18984篇
神经病学   71386篇
特种医学   36445篇
外国民族医学   336篇
外科学   142105篇
综合类   19030篇
一般理论   247篇
预防医学   64556篇
眼科学   20083篇
药学   63805篇
中国医学   1798篇
肿瘤学   49098篇
  2018年   9048篇
  2017年   7160篇
  2016年   7674篇
  2015年   8722篇
  2014年   12367篇
  2013年   19210篇
  2012年   25647篇
  2011年   27256篇
  2010年   16572篇
  2009年   15780篇
  2008年   26124篇
  2007年   27731篇
  2006年   27913篇
  2005年   27444篇
  2004年   26291篇
  2003年   25461篇
  2002年   25051篇
  2001年   41356篇
  2000年   42551篇
  1999年   36265篇
  1998年   9966篇
  1997年   9148篇
  1996年   9082篇
  1995年   8445篇
  1994年   8081篇
  1993年   7584篇
  1992年   28198篇
  1991年   26979篇
  1990年   26408篇
  1989年   25345篇
  1988年   23553篇
  1987年   23170篇
  1986年   22250篇
  1985年   21151篇
  1984年   15806篇
  1983年   13477篇
  1982年   8087篇
  1979年   14589篇
  1978年   10208篇
  1977年   8627篇
  1976年   8147篇
  1975年   8959篇
  1974年   10697篇
  1973年   10182篇
  1972年   9661篇
  1971年   8917篇
  1970年   8584篇
  1969年   8025篇
  1968年   7684篇
  1967年   7086篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
46.
To examine the prevalence of Internet sex networking among men who have sex with men (MSM) in Hong Kong and risk behaviors associated with the behavior, a telephone survey of 15,230 Hong Kong Chinese men aged 18-60 was conducted. Of the 283 active MSM (having engaged in some MSM behaviors in the last 6 months) identified, 17.7% had networked for MSM partners via the Internet in the last 6 months. Younger age (odds ratio [OR] for age < or = 25 vs. age >25 = 4.67, 95% confidence interval [CI] = 2.35-9.28) and being an anal-sex MSM (OR = 4.72, 95% CI=2.36-9.44) were independent predictors of Internet sex networking. Being an Internet sex networker was associated with some risk behaviors such as having contracted a sexually transmitted disease (adjusted OR = 4.79, 95% CI = 1.34-17.11), having had > or = 3 MSM partners (adjusted OR = 4.74, 95% CI = 2.20-10.23), and having engaged in anal sex (adjusted OR = 3.95, 95% CI = 1.89-8.23). HIV prevention programs for MSM should thereby include Internet-based interventions.  相似文献   
47.
48.
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases.  相似文献   
49.
The involvement of oxidative stress in polymorphonuclear leukocytes (PMN) in the pathogenesis of hypertension remains to be elucidated. We analyzed the generation of reactive oxygen species (ROS) by the circulating and peritoneally infiltrating PMN from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Flow cytometric analysis revealed that ROS generation by PMN from SHR was higher than that from WKY before (at 6 weeks of age) and after (at 16 weeks of age) the onset of hypertension. In vivo, ROS generation by PMN from SHR, but not that by PMN from WKY, was significantly suppressed by 10-week treatment with 50 mg/kg/day carvedilol, and this treatment did not affect blood pressure. Western blotting analysis revealed that protein kinase C alpha (PKCalpha), but not PKCbetaI or betaII, was activated more strongly in PMN from SHR than in PMN from WKY. Furthermore, expression of p47phox of nicotinamide adenine dinucleotide phosphate oxidase, but not of p67phox, in PMN from SHR was higher than that in PMN from WKY. These results suggest that ROS generation by PMN is principally enhanced in SHR through activation of PKCalpha and p47phox.  相似文献   
50.
We report the case of a patient with a 13-year history of pemphigus vulgaris (PV) treated with immunosuppressive agents, prednisone and mycophenolate mofetil who had developed lesions of Kaposi's sarcoma (KS) on a sole plaque of PV that had been previously treated with intralesional injections of steroids. The lesions were surgically removed and polymerase chain reaction (PCR) demonstrated human herpesvirus-8 (HHV-8) DNA. There were neither recurrences nor later dissemination of KS following gradual decrease of the immunosuppressive therapy. We suggest that the treatment with intralesional steroids may have influenced the local reactivation of a latent infection of the virus, determining the appearance of this localized KS.  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