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   2882932篇
  免费   218100篇
  国内免费   5444篇
耳鼻咽喉   38846篇
儿科学   95057篇
妇产科学   79959篇
基础医学   409174篇
口腔科学   85621篇
临床医学   258693篇
内科学   557215篇
皮肤病学   63665篇
神经病学   228455篇
特种医学   111930篇
外国民族医学   698篇
外科学   436934篇
综合类   70049篇
现状与发展   6篇
一般理论   1010篇
预防医学   220038篇
眼科学   68238篇
药学   214668篇
  9篇
中国医学   6363篇
肿瘤学   159848篇
  2018年   30241篇
  2017年   23295篇
  2016年   25698篇
  2015年   29432篇
  2014年   40865篇
  2013年   60998篇
  2012年   83656篇
  2011年   88191篇
  2010年   52256篇
  2009年   49144篇
  2008年   82987篇
  2007年   87957篇
  2006年   88852篇
  2005年   85613篇
  2004年   83547篇
  2003年   79785篇
  2002年   77421篇
  2001年   140782篇
  2000年   144839篇
  1999年   121240篇
  1998年   32800篇
  1997年   29209篇
  1996年   29153篇
  1995年   28150篇
  1994年   26201篇
  1993年   24381篇
  1992年   96073篇
  1991年   93327篇
  1990年   90490篇
  1989年   87287篇
  1988年   80418篇
  1987年   78842篇
  1986年   74913篇
  1985年   71889篇
  1984年   53277篇
  1983年   45754篇
  1982年   26358篇
  1981年   23580篇
  1979年   49375篇
  1978年   34045篇
  1977年   28944篇
  1976年   27161篇
  1975年   28758篇
  1974年   35078篇
  1973年   33714篇
  1972年   31142篇
  1971年   29217篇
  1970年   27013篇
  1969年   25304篇
  1968年   23304篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A general overview of the literature concerning the development of diabetic neuropathic arthropathy is discussed. A case report is presented dealing with spontaneous fractures of the lesser metatarsal in a patient with an amputated hallux and peripheral neuropathy secondary to diabetes mellitus.  相似文献   
992.
993.
994.
Circulating immune complexes (CIC), adult schistosome antibody, and total immunoglobulin concentrations were estimated in sera from 35 chronic Schistosoma mansoni patients with different infection intensities and different pathological complications. High CIC levels were present in about one-third (10/35) of the sera. Most of the patients (9/10) with elevated CIC levels also had hepatomegaly or hepatosplenomegaly. This finding is significant in the pathogenesis of schistosomal liver fibrosis and may also apply to other liver diseases, especially cirrhosis. No correlation was found between infection intensity as judged by stool egg counts and CIC levels. A reverse relationship was observed between the level of anti-adult worm IgG and CIC levels. CIC levels were elevated within 7 and 28 days after treatment in most patients. Hypergammaglobulinaemia was detected in most sera.  相似文献   
995.
996.
997.
The effect of zinc deficiency on intestinal absorption of cholesterol was investigated in adult male rats fed 3.6 ppm of dietary zinc (ZD) and compared with pair-fed (PF) and ad-libitum (CT) controls fed 30.6 ppm of zinc for 10 to 12 wk. The intestinal absorption of cholesterol was measured by collecting the mesenteric lymph at hourly intervals for 8 h after infusing a dose of [14C]cholesterol in a lipid emulsion through an indwelling duodenal catheter. Data on the hourly lymphatic output of [14C]cholesterol showed that the absorption of [14C]cholesterol plateaued at 4 h postdosing in all groups. The rate of the appearance of [14C]cholesterol in the mesenteric lymph significantly decreased in ZD rats at 5 h and thereafter. The cumulative absorption of [14C]cholesterol by ZD rats for the 8-h period was 4.4 +/- 1.0% of the dose, compared with 11.8 +/- 1.1% by PF and 10.7 +/- 1.4% by CT rats. There were no differences in percent distribution of esterified [14C]cholesterol among the three groups. Also, no significant change in mucosal cholesterol esterase activity was observed due to zinc deficiency. The present data and previous findings taken together suggest that the primary mechanism responsible for the impaired absorption of cholesterol may be associated with defective formation of chylomicrons in the intestinal mucosa.  相似文献   
998.
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   
999.
We used the perfused hemicorpus preparation to measure individual rates of protein synthesis and degradation. Using fed animals, perfused either with or without insulin, muscle protein synthesis and hemicorpus protein degradation rates were similar, but myofibrillar protein degradation was clearly increased in the uremic preparations. When the animals were fasted, differences in the rates of skeletal muscle protein turnover were apparent. Uremic rats lost more wt at both 24 and 48 hr of fasting when compared to either ad libitum fed or pair-fed controls who started fasting at body wts equivalent to our uremic rats. The accelerated wt loss was accompanied by lower rates of protein synthesis, higher degradation rates, and greater net protein catabolism in our uremic rats. Alterations in body lipid content were present in uremia and correlated with the rate of protein degradation in both control and uremic rats. These data demonstrated that even in the fed state, uremia is associated with subtle alterations in skeletal muscle protein turnover. When stressed, these alterations become more pronounced. Insufficient stores of body lipids, either due to inadequate nutrition or altered metabolism, may contribute to the alterations in muscle protein turnover seen in chronic renal insufficiency.  相似文献   
1000.
Platelet activation: role of an ADP receptor   总被引:3,自引:0,他引:3  
  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