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   1265701篇
  免费   72470篇
  国内免费   1366篇
耳鼻咽喉   16336篇
儿科学   41195篇
妇产科学   31892篇
基础医学   174087篇
口腔科学   31107篇
临床医学   107781篇
内科学   237263篇
皮肤病学   25204篇
神经病学   98834篇
特种医学   52337篇
外国民族医学   201篇
外科学   195499篇
综合类   24356篇
现状与发展   1篇
一般理论   263篇
预防医学   93170篇
眼科学   27304篇
药学   96393篇
  7篇
中国医学   3432篇
肿瘤学   82875篇
  2019年   7777篇
  2018年   33982篇
  2017年   27054篇
  2016年   31267篇
  2015年   12245篇
  2014年   16059篇
  2013年   22938篇
  2012年   37377篇
  2011年   53786篇
  2010年   37902篇
  2009年   29854篇
  2008年   51020篇
  2007年   56545篇
  2006年   33209篇
  2005年   33836篇
  2004年   34046篇
  2003年   34512篇
  2002年   31190篇
  2001年   60456篇
  2000年   62176篇
  1999年   51194篇
  1998年   12710篇
  1997年   11322篇
  1996年   11188篇
  1995年   10502篇
  1994年   9537篇
  1993年   9014篇
  1992年   37919篇
  1991年   36442篇
  1990年   35919篇
  1989年   34422篇
  1988年   30986篇
  1987年   30116篇
  1986年   28317篇
  1985年   26554篇
  1984年   19253篇
  1983年   16189篇
  1982年   8920篇
  1979年   17121篇
  1978年   11469篇
  1977年   10245篇
  1976年   8907篇
  1975年   10075篇
  1974年   11692篇
  1973年   11283篇
  1972年   10756篇
  1971年   10092篇
  1970年   9289篇
  1969年   8981篇
  1968年   7950篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.

Background

The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.

Objectives

The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.

Methods

PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.

Results

Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).

Conclusions

In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550)  相似文献   
42.
43.
The Impella 5.0, a percutaneously inserted left ventricular assist device, has been used to support patients who have severe heart failure or who are undergoing high-risk percutaneous coronary intervention. We report our surgical placement of the Impella 5.0, through a graft sewn to the aorta, to unload the left ventricle of a 59-year-old man who was undergoing venoarterial extracorporeal membrane oxygenation for postcardiotomy shock. The patient underwent successful placement of a long-term left ventricular assist device before his discharge from the hospital. The versatility of the Impella 5.0 is exemplified in this patient who was successfully bridged to long-term support.  相似文献   
44.
45.
46.
47.
48.
ABSTRACT

Objectives: The present study investigated the relationships of enculturation and depressive symptoms with health risk behavior engagement in Mexican-American college students and examined how these relationships differed by gender. Previous research has noted consistent gender differences in health risk behavior (e.g. alcohol use, substance use, and risky sexual behavior) among Latina/os, and emphasized the role of U.S. acculturation in this difference. Research examining the role of heritage cultural retention (i.e. enculturation), and including the added influence of mental health variables, such as depressive symptoms, is currently lacking. This study sought to address this gap.

Design: A large sample (N?=?677) of Mexican-American college students from four universities (located in New York, California, Florida, and Texas) completed an online questionnaire assessing health risk behaviors and corresponding variables.

Results: We found that males who endorsed more behavioral enculturation and depressive symptoms were more likely to engage in health risk behavior than all others in the sample. Contrary to previous literature, no relationship was found between behavioral enculturation and health risk behavior in females.

Conclusion: The current study found behavioral enculturation to be associated with depressive symptoms, and in turn with health risk behaviors among the males in our sample. Additional research will be needed to identify the mechanism underlying the relationship between enculturation and depressive symptoms as well as between depressive symptoms and risky behavior.  相似文献   
49.
50.
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