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   23377篇
  免费   1670篇
  国内免费   90篇
耳鼻咽喉   169篇
儿科学   808篇
妇产科学   545篇
基础医学   3367篇
口腔科学   339篇
临床医学   2868篇
内科学   5118篇
皮肤病学   486篇
神经病学   2463篇
特种医学   445篇
外科学   2080篇
综合类   144篇
一般理论   28篇
预防医学   2576篇
眼科学   252篇
药学   1552篇
中国医学   45篇
肿瘤学   1852篇
  2024年   20篇
  2023年   218篇
  2022年   390篇
  2021年   769篇
  2020年   516篇
  2019年   774篇
  2018年   790篇
  2017年   591篇
  2016年   664篇
  2015年   727篇
  2014年   923篇
  2013年   1210篇
  2012年   1960篇
  2011年   1979篇
  2010年   1056篇
  2009年   887篇
  2008年   1536篇
  2007年   1593篇
  2006年   1565篇
  2005年   1456篇
  2004年   1339篇
  2003年   1180篇
  2002年   1036篇
  2001年   146篇
  2000年   102篇
  1999年   168篇
  1998年   202篇
  1997年   141篇
  1996年   141篇
  1995年   127篇
  1994年   89篇
  1993年   96篇
  1992年   55篇
  1991年   61篇
  1990年   62篇
  1989年   66篇
  1988年   51篇
  1987年   41篇
  1986年   45篇
  1985年   34篇
  1984年   51篇
  1983年   32篇
  1982年   28篇
  1981年   30篇
  1980年   21篇
  1979年   21篇
  1978年   18篇
  1977年   16篇
  1976年   17篇
  1973年   14篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Introduction: Current research suggests that pediatric stroke is associated with a reduction in intellectual functioning. However, less is known about academic achievement and the contribution of specific executive functions to math and literacy in this population. The current study investigates behavioral ratings of executive functioning and their relationship to math and spelling performance in children with a history of unilateral arterial ischemic stroke.

Method: Thirty-two pediatric patients with stroke (Mage = 9.5 ± 2.7 years) and 32 demographically equivalent, healthy controls were tested on standardized measures of arithmetic, spelling, and intelligence. Executive functioning data were collected via standardized parent questionnaire.

Results: Relative to controls, stroke participants demonstrated significantly poorer functioning in math, spelling, metacognition, and behavioral-regulation. Pencil and paper arithmetic was particularly challenging for the stroke group, with 40% of patients reaching levels of clinical impairment. Hierarchical regression in stroke participants further revealed that metacognition was a robust predictor of academic deficits. Stroke occurring in later childhood and affecting cortical and subcortical brain regions also presented as potential clinical risk factors.

Conclusions: Children with stroke were especially vulnerable to math achievement deficits. Metacognition made a substantial contribution to academic achievement abilities among stroke patients, and results underscore the importance of early metacognitive skills in the completion of schoolwork. Results also emphasize that pediatric stroke patients are a heterogeneous group with regard to functioning and that there is value in examining standard score distributions of clinical participant samples.  相似文献   

2.
3.
BACKGROUND: Stressful conditions lead to formation of excessive free radicals, and lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products. OBJECTIVES: To determine the levels of malondialdehyde, an end product of lipid peroxidation, according to demographic and occupational variables in workers of a prehospital emergency service and to analyse the relationship between malondialdehyde levels and burnout. MATERIAL AND METHODS: One hundred and eleven healthy workers of a prehospital emergency service and eighty aged-matched healthy individuals of both sexes as a control group were surveyed. Malondialdehyde levels were measured by the Bull and Marnett method. To measure burnout, the Maslach Burnout Inventory was used. RESULTS: Professional category is associated with lipid peroxidation and burnout levels (Malondialdehyde levels were: physicians 338.10+/-14.47, nurses 329.17+/-12.62 and technicians 296.74+/-14.28; burnout levels were: physicians 41.29+/-3.59, nurses 37.38+/-6.05 and technicians 35.33+/-5.87). Working at night and in the evening increased malondialdehyde and burnout levels. Malondialdehyde levels increase with age. No significant variations with respect to sex were detected. Significant variations in malondialdehyde levels were detected between singles (303.13+/-12.74) and married people (344.43+/-13.43) but not with respect to divorcees (326.44+/-11.74). Significant differences were detected in erythrocyte malondialdehyde levels between smokers (341.37+/-17.09) and nonsmokers (302.21+/-12.38), but not for alcohol consumption. CONCLUSIONS: These findings suggest a positive correlation between malondialdehyde, a biomarker of lipid peroxidation and occupational stress, as estimated by elements of the Maslach Burnout Inventory, and oxidative stress.  相似文献   
4.
5.
Successful efforts in improving breastfeeding initiation rates at an urban teaching hospital prompted the hospital to create a lactation consultant (LC) position in the outpatient setting to focus on breastfeeding duration. This article reviews the complexity of the clinic setting, with the challenges and benefits of the consultant's first year in one of the hospital's outpatient clinics. Preliminary data collected by the consultant suggest that patients counseled by the LC in the outpatient clinic setting have longer breastfeeding duration rates.  相似文献   
6.
7.
Heart failure is reaching epidemic proportions in the United States, causing a constellation of disabling symptoms. Cognitive impairment in people with heart failure may be more common than previously known with multiple etiologies from both the disease process and the treatment. Exemplars from a research study are used to illustrate the perspective of heart failure patients. Given the critical importance of memory deficits on patient education, potential nursing interventions to address the issue of cognitive impairment are described.  相似文献   
8.
Prisons and prison inmates present important targets for HIV/AIDS prevention interventions. Inmates often have histories of high-risk behavior that place them in danger of contracting HIV/AIDS, and rates of HIV/AIDS tend to be much higher in this population. The goal of this study was to assess the effectiveness of a prison-based HIV/AIDS intervention to change attitudes toward HIV prevention, norms supporting HIV prevention, perceived behavioral control (i.e., self-efficacy) for HIV prevention behaviors, and intentions to engage in HIV prevention behaviors postrelease. The intervention also had the goal of encouraging inmates to become HIV/AIDS peer educators. The intervention appeared most successful at influencing beliefs and behaviors related to peer education and somewhat successful at influencing beliefs and intentions related to condom use. Analyses also showed some significant differences in effectiveness by race/ethnicity. Results are discussed from the perspectives of both research and practice with regard to prison-based HIV prevention efforts.  相似文献   
9.
10.
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