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   936282篇
  免费   67886篇
  国内免费   1359篇
耳鼻咽喉   13002篇
儿科学   24442篇
妇产科学   23383篇
基础医学   133772篇
口腔科学   28377篇
临床医学   80866篇
内科学   184367篇
皮肤病学   19392篇
神经病学   72738篇
特种医学   37194篇
外国民族医学   79篇
外科学   153065篇
综合类   18055篇
现状与发展   1篇
一般理论   235篇
预防医学   61829篇
眼科学   21413篇
药学   72889篇
  3篇
中国医学   2174篇
肿瘤学   58251篇
  2018年   9073篇
  2017年   7124篇
  2016年   7863篇
  2015年   8990篇
  2014年   12149篇
  2013年   17709篇
  2012年   24423篇
  2011年   25391篇
  2010年   14988篇
  2009年   14418篇
  2008年   24930篇
  2007年   26011篇
  2006年   26766篇
  2005年   25723篇
  2004年   24853篇
  2003年   23919篇
  2002年   23463篇
  2001年   54868篇
  2000年   56704篇
  1999年   47075篇
  1998年   10796篇
  1997年   9515篇
  1996年   9645篇
  1995年   8978篇
  1994年   8334篇
  1993年   7635篇
  1992年   35585篇
  1991年   34011篇
  1990年   32827篇
  1989年   31979篇
  1988年   29096篇
  1987年   28351篇
  1986年   26376篇
  1985年   25212篇
  1984年   17881篇
  1983年   15180篇
  1982年   7829篇
  1981年   6800篇
  1979年   15819篇
  1978年   10641篇
  1977年   9081篇
  1976年   7889篇
  1975年   8649篇
  1974年   10487篇
  1973年   9879篇
  1972年   9388篇
  1971年   8885篇
  1970年   8451篇
  1969年   7946篇
  1968年   7223篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
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   
92.
93.
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   
94.
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   

95.
Congenital rubella syndrome (CRS) results from maternal rubella virus infection in early pregnancy. Abnormal neuroimaging findings have been analyzed in a small number of CRS patients in the past; however, their clinical significance has been poorly addressed. Therefore, we have investigated the neuroimaging findings of 31 patients with CRS from previous studies. The most common finding was parenchymal calcification, which was observed in 18 of 31 patients (58.1%). A multivariable logistic regression model showed that it was associated with psychomotor or mental retardation (p = 0.018), suggesting that parenchymal calcification in CRS could be a prognostic factor.  相似文献   
96.
97.

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   
98.
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   
99.
100.
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