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   1484039篇
  免费   113175篇
  国内免费   2858篇
耳鼻咽喉   20678篇
儿科学   49740篇
妇产科学   38806篇
基础医学   208137篇
口腔科学   37624篇
临床医学   132613篇
内科学   300874篇
皮肤病学   30833篇
神经病学   121667篇
特种医学   60313篇
外国民族医学   673篇
外科学   228898篇
综合类   29306篇
现状与发展   2篇
一般理论   543篇
预防医学   110440篇
眼科学   32938篇
药学   108547篇
  3篇
中国医学   2716篇
肿瘤学   84721篇
  2021年   12596篇
  2019年   13438篇
  2018年   18418篇
  2017年   13844篇
  2016年   15163篇
  2015年   17391篇
  2014年   24462篇
  2013年   36220篇
  2012年   51137篇
  2011年   53936篇
  2010年   31737篇
  2009年   30149篇
  2008年   50710篇
  2007年   54054篇
  2006年   53966篇
  2005年   52694篇
  2004年   51077篇
  2003年   48726篇
  2002年   47524篇
  2001年   65735篇
  2000年   67807篇
  1999年   58196篇
  1998年   17606篇
  1997年   15738篇
  1996年   15926篇
  1995年   15034篇
  1994年   14139篇
  1993年   13149篇
  1992年   45440篇
  1991年   44298篇
  1990年   42922篇
  1989年   40782篇
  1988年   37506篇
  1987年   36767篇
  1986年   34201篇
  1985年   32894篇
  1984年   24971篇
  1983年   20991篇
  1982年   12660篇
  1981年   11566篇
  1979年   21777篇
  1978年   15294篇
  1977年   12943篇
  1976年   12079篇
  1975年   12906篇
  1974年   14945篇
  1973年   14363篇
  1972年   13105篇
  1971年   11872篇
  1970年   11153篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
991.
992.
Pericardial effusion complicating breast cancer.   总被引:2,自引:0,他引:2       下载免费PDF全文
Thirty-five patients with metastatic breast cancer and pericardial effusions are described. They were treated with specific endocrine or chemotherapy. Twenty-two (63%) had presented in cardiac tamponade and were rapidly relieved by pericardiocentesis. Eighteen (82%) of these required no further local treatment, 2 obtained relief from a second aspiration and 2 needed additional treatment (intrapericardial bleomycin instillation and surgical pleuropericardial window). The median survival was 13.2 months. No patient relapsed again in the pericardium, suggesting that their prognosis was that of the underlying disease. Cardiac tamponade should be considered in any breathless patient with malignancy. In breast cancer, periocardiocentesis is lifesaving and systemic treatment can usefully prolong life.  相似文献   
993.
One hundred and one children over 1 year of age have had surgery for pelviureteric obstruction over an 11 year period. The common clinical features were abdominal pain, urinary infection or haematuria, but number presented as an incidental finding. Less commonly, the patients presented with an abdominal mass or with hypertension. The diagnosis was usually made on intravenous pyelography (IVP) but in the latter part of the series, renal nuclide scan (RNS) and ultrasonography (US) were preferred. Ninety–three patients had unilateral pyeloplasty, three had bilateral pyeloplasty and five had nephrectomy or heminephrectomy. Whereas initially nephrostomy drainage was used in the majority of patients after pyeloplasty, trend away from nephrostomy evolved in the latter part of the series. With experience, the incidence of postoperative complications was also reduced and there was reduction in the period of hospitalization. Clinical results were consistently satisfactory. Postoperative assessment after pyeloplasty was made by IVP and/or RNS and also US. A review of these investigations showed that RNS provided more factual information of the result when compared with the IVP.  相似文献   
994.
995.
Mouse polyclonal antisera were raised to the Mr 130,000 and Mr 115,000 cell surface glycoproteins, desmocollins, of desmosomes from bovine nasal epithelium. Immunoblotting confirmed that the antisera were specific for the desmocollins. An immunofluorescence study showed that the antisera distinguished between the basal and suprabasal layers of bovine and human epidermis. The antibodies reacted with cultured keratinocytes only after calcium-induced stratification. In epidermis, therefore, there appears to be a difference between the desmocollins of basal and suprabasal cells that may be important in relation to epidermal differentiation. Previous work has shown that polyclonal antisera raised in other animals (guinea pigs and rabbits) against desmocollins, as well as against other desmosomal components, react with all desmosome-containing epithelia. In contrast, an immunofluorescence survey of bovine, rat, and human tissues showed that the present mouse antisera stained only suprabasal skin cells and the arachnoid layer of the meninges, demonstrating that these have common determinants that distinguished their desmocollins from those of all other tissues. The antibodies also stained 11 of 12 meningiomas and, therefore, may be useful as a marker not only for the diagnosis of these tumors but also for investigation of their histogenesis.  相似文献   
996.
Pharmacosomes--a novel drug delivery system   总被引:2,自引:0,他引:2  
  相似文献   
997.
To ascertain the effect of theophylline on the cardiac chronotropic response to beta-adrenergic stimulation, isoproterenol dose-response curves in healthy young subjects were compared during saline and theophylline maintenance infusions. Each study was repeated 1 to 3 weeks later to evaluate reproducibility. Neither the dose of isoproterenol required to raise the heart rate by 25 bpm (2.32 +/- 0.81 vs. 1.55 +/- 0.46 micrograms on day 1 and 1.28 +/- 0.22 vs. 1.27 +/- 0.25 micrograms on day 2) nor the slopes of the dose-response curves were affected by theophylline. Higher heart rates were observed after isoproterenol bolus dosing during theophylline than during saline infusion because of additive chronotropic effects of theophylline and isoproterenol. Since theophylline does not interact in a synergistic fashion with isoproterenol, phosphodiesterase inhibition appears to be an unlikely mechanism of the chronotropic effect of methylxanthines at therapeutic concentrations.  相似文献   
998.
999.
1000.
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