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   900275篇
  免费   62482篇
  国内免费   2340篇
耳鼻咽喉   12478篇
儿科学   28772篇
妇产科学   26168篇
基础医学   126662篇
口腔科学   24687篇
临床医学   74788篇
内科学   183353篇
皮肤病学   19004篇
神经病学   71466篇
特种医学   36448篇
外国民族医学   336篇
外科学   142182篇
综合类   19035篇
一般理论   247篇
预防医学   64578篇
眼科学   20089篇
药学   63849篇
中国医学   1800篇
肿瘤学   49155篇
  2018年   9068篇
  2017年   7175篇
  2016年   7696篇
  2015年   8738篇
  2014年   12388篇
  2013年   19242篇
  2012年   25683篇
  2011年   27297篇
  2010年   16588篇
  2009年   15794篇
  2008年   26155篇
  2007年   27755篇
  2006年   27931篇
  2005年   27480篇
  2004年   26325篇
  2003年   25495篇
  2002年   25074篇
  2001年   41367篇
  2000年   42581篇
  1999年   36281篇
  1998年   9971篇
  1997年   9153篇
  1996年   9088篇
  1995年   8449篇
  1994年   8082篇
  1993年   7588篇
  1992年   28213篇
  1991年   26991篇
  1990年   26419篇
  1989年   25349篇
  1988年   23562篇
  1987年   23183篇
  1986年   22257篇
  1985年   21160篇
  1984年   15811篇
  1983年   13485篇
  1982年   8090篇
  1979年   14597篇
  1978年   10216篇
  1977年   8631篇
  1976年   8150篇
  1975年   8967篇
  1974年   10704篇
  1973年   10186篇
  1972年   9668篇
  1971年   8919篇
  1970年   8587篇
  1969年   8028篇
  1968年   7697篇
  1967年   7090篇
排序方式: 共有10000条查询结果,搜索用时 0 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