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   4063841篇
  免费   307770篇
  国内免费   10194篇
耳鼻咽喉   57474篇
儿科学   130327篇
妇产科学   111117篇
基础医学   568367篇
口腔科学   116933篇
临床医学   374871篇
内科学   788435篇
皮肤病学   91247篇
神经病学   337943篇
特种医学   158583篇
外国民族医学   1438篇
外科学   610033篇
综合类   91153篇
现状与发展   6篇
一般理论   1720篇
预防医学   324860篇
眼科学   94627篇
药学   301168篇
  11篇
中国医学   7982篇
肿瘤学   213510篇
  2018年   43658篇
  2017年   33594篇
  2016年   38163篇
  2015年   43077篇
  2014年   60655篇
  2013年   92092篇
  2012年   122380篇
  2011年   129845篇
  2010年   77868篇
  2009年   74435篇
  2008年   121870篇
  2007年   129431篇
  2006年   131213篇
  2005年   126858篇
  2004年   122234篇
  2003年   117856篇
  2002年   114690篇
  2001年   187065篇
  2000年   192555篇
  1999年   163309篇
  1998年   48490篇
  1997年   43273篇
  1996年   42909篇
  1995年   41618篇
  1994年   38641篇
  1993年   36158篇
  1992年   129765篇
  1991年   125543篇
  1990年   121347篇
  1989年   117257篇
  1988年   108380篇
  1987年   106758篇
  1986年   100828篇
  1985年   96591篇
  1984年   72645篇
  1983年   62039篇
  1982年   37362篇
  1981年   33617篇
  1979年   66751篇
  1978年   47241篇
  1977年   40027篇
  1976年   37497篇
  1975年   39598篇
  1974年   47990篇
  1973年   45816篇
  1972年   43110篇
  1971年   39926篇
  1970年   37311篇
  1969年   35278篇
  1968年   32454篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
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   
992.
Abstract: The current study examined the extent to which mothers, fathers, teachers, and teenage friends influenced Latino adolescents’ academic motivation. Using path analysis, separate models were tested for 154 Latino boys and 156 Latina girls. Findings indicated that mothers’ and teachers’ academic support were positively related to adolescent girls’ academic motivation, and fathers’ and teachers’ academic support were positively related to adolescent boys’ academic motivation. The salience of teachers’ support, possible reasons for gender differences, and implications for future research are discussed.  相似文献   
993.
Sugar and tooth decays are bound closely. The mechanisms of destruction of the tooth from the glycolyse are known. The role played by the food in the development of the caries is unique. Foods sweetened of all ways, rich in sucrose are responsible of the intervening of the carious lesions. The transformation of the fermentable sugars in lactic with the absence of hygiene and the action conjugated of the bacteria leads to tooth decays in temporary and permanent denture that evolve very quickly in the absence of treatment. Reasons for which the authors put in evidence in this survey, the influence of the food sweetened on the teeth at the children while showing the cases of caries and its complications due to the excessive consumption of fermentable hydrates of carbon.  相似文献   
994.
995.
996.
997.
The clinical presentation of electrical injury commonly involves physical, cognitive, and emotional complaints. Neuropsychological studies, including case reports, have indicated that electrical injury (EI) survivors may experience a broad range of impaired neuropsychological functions, although this has not been clarified through controlled investigation. In this study, we describe the neuropsychological test findings in a series of 29 EI patients carefully screened and matched to a group of 29 demographically similar healthy electricians. Participants were matched by their estimated premorbid intellectual ability. Multivariate analysis of variance was used to assess group differences in the following neuropsychological domains: attention and mental speed, working memory, verbal memory, visual memory, and motor skills. EI patients performed significantly worse on composite measures of attention/mental speed and motor skills, which could not be explained by demographic differences, injury parameters, litigation status, or mood disturbance. Results suggest that cognitive changes do occur in patients suffering from electrical injury.  相似文献   
998.
999.
1000.
BACKGROUND: Previous research has demonstrated that academic and neuropsychological functions are compromised in pediatric bipolar disorder (PBD). Investigation of the degree to which neuropsychological deficits might contribute to those academic problems is needed to aid in the recognition and intervention for school achievement difficulties in PBD. METHODS: A sample of 55 children and adolescents with PBD with and without attention-deficit/hyperactivity disorder (ADHD) (PBD group, n = 28; PBD+ADHD group, n = 27) were tested with a computerized neurocognitive battery and standardized neuropsychological tests. Age range of subjects was 7-17 years, with the mean age of 11.97 (3.18) years. Parents completed a structured questionnaire on school and academic functioning. RESULTS: Logistic regression analyses indicated that executive function, attention, working memory, and verbal memory scores were poorer in those with a history of reading/writing difficulties. A separate logistic regression analysis found that attentional dysfunction predicted math difficulties. These relationships between neuropsychological function and academic difficulties were not different in those with PBD+ADHD than in those with PBD alone. CONCLUSIONS: In PBD neuropsychological deficits in the areas of attention, working memory, and organization/problem solving skills all contribute to academic difficulties. Early identification and intervention for these difficulties might help prevent lower academic achievement in PBD.  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