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   1871724篇
  免费   136608篇
  国内免费   4354篇
耳鼻咽喉   23684篇
儿科学   60365篇
妇产科学   49835篇
基础医学   264429篇
口腔科学   52635篇
临床医学   168623篇
内科学   369934篇
皮肤病学   40963篇
神经病学   148441篇
特种医学   69587篇
外国民族医学   255篇
外科学   284258篇
综合类   41923篇
现状与发展   6篇
一般理论   808篇
预防医学   140983篇
眼科学   43848篇
药学   135927篇
  8篇
中国医学   4771篇
肿瘤学   111403篇
  2021年   15560篇
  2019年   16258篇
  2018年   23217篇
  2017年   17830篇
  2016年   19395篇
  2015年   22292篇
  2014年   31212篇
  2013年   45322篇
  2012年   63536篇
  2011年   67353篇
  2010年   39521篇
  2009年   36858篇
  2008年   62950篇
  2007年   66849篇
  2006年   66963篇
  2005年   64571篇
  2004年   62424篇
  2003年   59091篇
  2002年   56960篇
  2001年   93381篇
  2000年   94818篇
  1999年   78693篇
  1998年   22121篇
  1997年   19334篇
  1996年   19299篇
  1995年   18394篇
  1994年   16812篇
  1993年   15471篇
  1992年   58384篇
  1991年   56229篇
  1990年   53846篇
  1989年   51557篇
  1988年   47001篇
  1987年   45804篇
  1986年   43085篇
  1985年   40925篇
  1984年   30610篇
  1983年   26161篇
  1982年   15453篇
  1981年   13782篇
  1979年   26222篇
  1978年   18406篇
  1977年   15695篇
  1976年   14602篇
  1975年   15152篇
  1974年   18207篇
  1973年   17460篇
  1972年   16054篇
  1971年   14759篇
  1970年   13726篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
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   
32.
33.
34.
35.
Infections due to Penicillium species other than P.marneffei are rare. We identified a boy with X-linked chronic granulomatous disease (X-CGD) with a pulmonary nodule and adjacent rib osteomyelitis caused by Penicillium piceum. The only sign of infection was an elevated sedimentation rate. P. piceum was isolated by fine needle aspirate and from excised infected tissues. Surgical removal and one year of voriconazole treatment were very well tolerated and led to complete recovery. Microbiological, microscopic and molecular studies support the fungal diagnosis. P. piceum should be considered as a relevant pathogen in immunocompromised patients.  相似文献   
36.
B.  Greg  Brown  John  Growley  宋善俊 《美国医学会杂志》2006,25(2):124-126
过去15年来,有关动脉粥样硬化的流行病学、基础生物学和实验研究均支持下述假设:抗氧化剂可通过抑制动脉壁低密度脂蛋白的氧化而抑制动脉粥样硬化的发生。这种作用机制可抑制胆固醇酯通过巨噬细胞清除受体在动脉斑块内发生病理性沉积。胆固醇酯病理沉积是一种可引起斑块破裂及心血管事件的过程。同样,生物机制亦已确定,癌基因可被抗氧化剂阻断。  相似文献   
37.
38.
39.
40.
Although surgical lung resection could improve prognosis in some patients with multidrug-resistant tuberculosis (MDR-TB), there are no reports on the optimal candidates for this surgery. The aim of the present study was to elucidate the prognostic factors for surgery in patients with MDR-TB. Patients who underwent lung resection for the treatment of MDR-TB between March 1993 and December 2004 were included in the present study. Treatment failure was defined as greater than or equal to two of the five cultures recorded in the final 12 months of treatment being positive, any one of the final three cultures being positive, or the patient having died during treatment. The variables that affected treatment outcomes were identified through univariate and multivariate logistic regression analysis. In total, 79 patients with MDR-TB were included in the present study. The treatment outcomes of 22 (27.8%) patients were classified as failure. A body mass index <18.5 kg x m(-2), primary resistance, resistance to ofloxacin and the presence of a cavitary lesion beyond the range of the surgical resection were associated with treatment failure. Low body mass index, primary resistance, resistance to ofloxacin and cavitary lesions beyond the range of resection are possible poor prognostic factors for surgical lung resection in multidrug-resistant tuberculosis patients.  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