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   3218964篇
  免费   241338篇
  国内免费   8180篇
耳鼻咽喉   43735篇
儿科学   104509篇
妇产科学   87266篇
基础医学   462310篇
口腔科学   89451篇
临床医学   292885篇
内科学   630136篇
皮肤病学   73426篇
神经病学   257686篇
特种医学   124118篇
外国民族医学   743篇
外科学   488692篇
综合类   70620篇
现状与发展   14篇
一般理论   1167篇
预防医学   257319篇
眼科学   73514篇
药学   235484篇
  15篇
中国医学   5986篇
肿瘤学   169406篇
  2018年   35088篇
  2017年   26756篇
  2016年   30757篇
  2015年   34591篇
  2014年   48687篇
  2013年   73594篇
  2012年   97284篇
  2011年   103969篇
  2010年   62915篇
  2009年   60076篇
  2008年   97329篇
  2007年   103837篇
  2006年   105224篇
  2005年   102081篇
  2004年   97425篇
  2003年   94285篇
  2002年   90982篇
  2001年   146433篇
  2000年   150280篇
  1999年   126718篇
  1998年   38056篇
  1997年   33540篇
  1996年   34270篇
  1995年   33280篇
  1994年   30786篇
  1993年   28956篇
  1992年   100993篇
  1991年   98570篇
  1990年   95865篇
  1989年   92059篇
  1988年   84945篇
  1987年   83400篇
  1986年   78521篇
  1985年   75527篇
  1984年   56917篇
  1983年   48344篇
  1982年   29385篇
  1981年   26449篇
  1979年   52217篇
  1978年   37574篇
  1977年   31366篇
  1976年   29703篇
  1975年   31637篇
  1974年   37755篇
  1973年   35922篇
  1972年   33776篇
  1971年   31655篇
  1970年   29017篇
  1969年   27629篇
  1968年   25454篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
51.
Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength.  相似文献   
52.
Levels of the soluble form of the triggering receptor expressed on myeloid cells (sTREM)-1 are elevated in severe sepsis. However, it is not known whether sTREM-1 measurements can distinguish milder bacterial infections from noninfectious inflammation. The present authors studied whether serum sTREM-1 levels differ in community-acquired pneumonia, exacerbations of chronic obstructive pulmonary disease (COPD), asthma and controls, and whether sTREM-1 may be used as a surrogate marker for the need for antibiotics. Serum sTREM-1 levels in 150 patients with pneumonia, COPD and asthma exacerbations and 62 healthy controls were measured. Serum sTREM-1 levels were significantly elevated in pneumonia (median 295.2 ng x mL(-1)), COPD (280.3 ng x mL(-1)) and asthma exacerbations (184.0 ng x mL(-1)) compared with controls (83.1 ng x mL(-1)). Levels were higher in pneumonia and Anthonisen type 1 COPD exacerbations than in type 2 and 3 COPD and asthma exacerbations. The area under the receiver operating characteristics curve for sTREM-1 as a surrogate marker for the need for antibiotics was 0.77. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 were elevated predominantly in pneumonia and Anthonisen type 1 COPD exacerbations versus type 2 and 3 chronic obstructive pulmonary disease exacerbations, asthma and controls. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 has moderate but insufficient accuracy as a surrogate marker for the need for antibiotics in lower respiratory tract infections.  相似文献   
53.
The precise molecular cause of insulin resistance has not yet been elucidated. Resistance to the normal action of insulin contributes to the pathogenesis of a number of common human disorders, including type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus, hypertension, and the Metabolic Syndrome X, thus constituting a major public health problem. A disease program aimed at combating this disorder should focus on the identification of targets for therapeutic intervention which may overcome insulin resistance and hence the associated metabolic consequences characteristic of the Metabolic Syndrome. Although the primary defect in the pathogenesis of type 2 diabetes is unknown, genetic and environmental factors are likely to contribute to the manifestation of this progressive metabolic disorder, which is usually not clinically apparent until mid-life. Defects at the level of glucose uptake/phosphorylation characterize insulin resistance in skeletal muscle of type 2 diabetic patients. Identification of putative components of the insulin receptor-signaling pathway may offer insights into mechanisms involved in insulin resistance. Enhanced flux of free fatty acids due to impaired lipid metabolism may contribute to impaired insulin secretion and peripheral insulin resistance. Genes regulating lipolysis are prime candidates for susceptibility towards the metabolic syndrome. Here we describe pathways constituting complex interactions that control glucose homeostasis. We will be considering (1) regulation of glucose uptake by the insulin receptor signaling pathway, and (2) control of adipogenesis and insulin sensitivity by the sterol response element binding protein (SREBP) pathway.  相似文献   
54.
55.
56.
Imaging     
  相似文献   
57.
58.
59.
60.
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