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   506篇
  免费   23篇
  国内免费   4篇
耳鼻咽喉   27篇
儿科学   8篇
妇产科学   14篇
基础医学   50篇
口腔科学   15篇
临床医学   45篇
内科学   132篇
皮肤病学   5篇
神经病学   18篇
特种医学   31篇
外科学   104篇
综合类   9篇
预防医学   11篇
眼科学   32篇
药学   18篇
中国医学   3篇
肿瘤学   11篇
  2023年   2篇
  2022年   3篇
  2021年   9篇
  2020年   6篇
  2019年   10篇
  2018年   12篇
  2017年   9篇
  2016年   15篇
  2015年   25篇
  2014年   33篇
  2013年   51篇
  2012年   23篇
  2011年   20篇
  2010年   23篇
  2009年   11篇
  2008年   36篇
  2007年   43篇
  2006年   50篇
  2005年   35篇
  2004年   34篇
  2003年   27篇
  2002年   20篇
  2001年   8篇
  2000年   4篇
  1999年   2篇
  1998年   5篇
  1997年   4篇
  1996年   2篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1982年   1篇
  1970年   1篇
排序方式: 共有533条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Substance use is a threat to the health and well-being of youths, their families, and society as well. The literature shows that social interactions with peers, parents, and community may have an impact on adolescents’ behavior. Using data from the National Survey on Drug Use and Health of 2007, this study investigated the impact of social capital on youth behavior. The results show that peer influence is the strongest among the three significant predictors of substance use. While peer influence is positively correlated with substance use, family attachment and youth activities have a negative relationship with substance use. Findings demonstrate that there is a relationship between youth substance use and different aspects of social capital. By integrating different perspectives in social capital and substance use, this study successfully demonstrates how social capital can be utilized as a policy and intervention tool.  相似文献   
6.
7.
Aims: The aim of this study is to investigate the effect of mitral stenosis (MS) on left atrial (LA) function using two‐dimensional speckle tracking echocardiography (2DSTE). Methods and Results: The study subjects consisted of 52 patients with asymptomatic MS and 52 control subjects. LA function was assessed using prototype speckle tracking software and manual tracking method. Maximal LA volume (LAVmax) and minimal LA volume (LAVmin) and LA volume before atrial contraction (LAVpre‐a) were measured. Using these volumes, LA reservoir, conduit and booster pump fuction parameters were calculated. Indexed LAVmax, LAVmin, and LAVpre‐a measurements via speckle tracking were highly correlated with manual tracing methods in both groups. Expansion index (67.8 ± 36.4 vs. 148.3 ± 44.2), diastolic emptying index (37.7 ± 12.9 vs. 58.0 ± 8.5), passive emptying (37.3 ± 14.1 vs. 70.4 ± 10.4) and passive emptying index (13.3 ± 6.3 vs. 41.3 ± 10.6) were decreased significantly in MS patients (P < 0.001). In contrast active emptying index (62.6 ± 4.1 vs. 29.5 ± 10.1) increased in MS group (P < 0.001) while active emptying (28.1 ± 13.0 vs. 28.3 ± 6.9) remained same among both groups. Conclusions: This is the first study relating LA volumes and function assessed by 2DSTE to MS. 2D speckle tracking analysis of LA volume is relatively easy and provides more detailed information regarding the changes in LA volumes during the cardiac cycle.  相似文献   
8.
A 53-year-old woman with hemiparesis and poor dexterity, underwent cosmetic blepharopigmentation on the both upper eyelids in the dermatology clinic of a private hospital. She was not asked for any information on her medical history and no informed consent was obtained and the procedure was performed without any protective ocular shields. The patient experienced severe lacrimation, discomfort, and increased sensitivity to light during and after the procedure. She also noticed blurred vision after the procedure. Ophthalmologic examination revealed tender and oedematous eyelids and corneal abrasions in both of her eyes. Topical antibiotics and preservative-free lubricants were able to recover her from her signs and symptoms at 1-week follow-up. It is recommended that cosmetic blepharopigmentation should be applied cautiously with patient’s informed consent after obtaining a thorough medical history and with protective ocular shields to avoid potential complications.  相似文献   
9.

Objectives

The present study aims to specify the role of l-carnitine in the pathogenesis of endometrial cancer by comparing the serum total l-carnitine levels of endometrial cancer patients with those of healthy women.

Methods

Serum total l-carnitine concentrations were measured in patients with endometrioid-type endometrial cancer (n = 20) and healthy controls (n = 20) who were matched with respect to age and body mass index (BMI).

Results

Stage I endometrial cancer was diagnosed in 12 women (60.0 %) whereas three women (15.0 %) had stage II disease, three women (15.0 %) had stage III disease and two women (10.0 %) had stage IV disease. The healthy controls and endometrial cancer patients were statistically similar in aspect of age, gravidity, parity, BMI, waist-to-thigh ratio, waist-to-hip ratio, menopause, complete blood count parameters, and serum biochemistry. Serum total l-carnitine levels of women with endometrial cancer were significantly lower than those of healthy women (respectively, 5,519.4 ± 2,712.5 vs 7,940.8 ± 3,566.6 ng/dl, p = 0.021). Moreover, serum total l-carnitine levels decreased significantly and progressively with advancing stage (stage I vs II vs III vs IV; 6,294.0 ± 2,885.1 vs 5,800.0 ± 441.2 vs 4,016.0 ± 2,833.3 vs 2,560.0 ± 67.9 ng/dl; p = 0.021).

Conclusions

This is the first study to hypothesize that l-carnitine deficiency participates in the pathogenesis of endometrial cancer by means of a mechanism which is unrelated with obesity and increased amount of fat in human body.
  相似文献   
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