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   1045154篇
  免费   75306篇
  国内免费   1755篇
耳鼻咽喉   14437篇
儿科学   27348篇
妇产科学   25116篇
基础医学   147573篇
口腔科学   30461篇
临床医学   92099篇
内科学   207092篇
皮肤病学   21032篇
神经病学   83279篇
特种医学   40755篇
外国民族医学   83篇
外科学   168863篇
综合类   19833篇
现状与发展   2篇
一般理论   392篇
预防医学   72047篇
眼科学   24009篇
药学   80612篇
  5篇
中国医学   2329篇
肿瘤学   64848篇
  2019年   7781篇
  2018年   11086篇
  2017年   8688篇
  2016年   9565篇
  2015年   11066篇
  2014年   15167篇
  2013年   22437篇
  2012年   31254篇
  2011年   32642篇
  2010年   19161篇
  2009年   18403篇
  2008年   31903篇
  2007年   33568篇
  2006年   34193篇
  2005年   33367篇
  2004年   32114篇
  2003年   31005篇
  2002年   30187篇
  2001年   55825篇
  2000年   57408篇
  1999年   48104篇
  1998年   12323篇
  1997年   10792篇
  1996年   10671篇
  1995年   9995篇
  1994年   9148篇
  1993年   8491篇
  1992年   36189篇
  1991年   34564篇
  1990年   33358篇
  1989年   32460篇
  1988年   29523篇
  1987年   28754篇
  1986年   26805篇
  1985年   25775篇
  1984年   18608篇
  1983年   15923篇
  1982年   8888篇
  1981年   7751篇
  1979年   16220篇
  1978年   11139篇
  1977年   9569篇
  1976年   8286篇
  1975年   9007篇
  1974年   10815篇
  1973年   10143篇
  1972年   9565篇
  1971年   8977篇
  1970年   8562篇
  1969年   8042篇
排序方式: 共有10000条查询结果,搜索用时 646 毫秒
111.
112.
Bulletin of Experimental Biology and Medicine - Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a...  相似文献   
113.
114.
Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism.  相似文献   
115.
Purpose of the study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design.

Material and methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility.

Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO2Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as “Working Memory” and “Verbal Fluency Tasks”.

Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.  相似文献   

116.
117.

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   
118.
Lung - Diaphragmatic paralysis (DP) is an important cause of dyspnea with many underlying etiologies; however, frequently no cause is identified despite extensive investigation. We hypothesized...  相似文献   
119.
120.
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