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   63683篇
  免费   3335篇
  国内免费   1514篇
耳鼻咽喉   472篇
儿科学   916篇
妇产科学   796篇
基础医学   4792篇
口腔科学   555篇
临床医学   8110篇
内科学   14205篇
皮肤病学   100篇
神经病学   4193篇
特种医学   5895篇
外国民族医学   2篇
外科学   11312篇
综合类   9452篇
现状与发展   3篇
预防医学   1361篇
眼科学   1059篇
药学   3487篇
  27篇
中国医学   1152篇
肿瘤学   643篇
  2024年   110篇
  2023年   978篇
  2022年   1868篇
  2021年   2566篇
  2020年   2220篇
  2019年   1951篇
  2018年   2046篇
  2017年   1846篇
  2016年   1916篇
  2015年   1981篇
  2014年   4273篇
  2013年   4088篇
  2012年   3453篇
  2011年   3877篇
  2010年   3272篇
  2009年   3353篇
  2008年   3453篇
  2007年   3470篇
  2006年   3100篇
  2005年   2546篇
  2004年   2057篇
  2003年   1800篇
  2002年   1418篇
  2001年   1381篇
  2000年   1074篇
  1999年   965篇
  1998年   939篇
  1997年   896篇
  1996年   681篇
  1995年   676篇
  1994年   565篇
  1993年   489篇
  1992年   453篇
  1991年   354篇
  1990年   313篇
  1989年   278篇
  1988年   263篇
  1987年   226篇
  1986年   195篇
  1985年   214篇
  1984年   175篇
  1983年   97篇
  1982年   146篇
  1981年   106篇
  1980年   92篇
  1979年   84篇
  1978年   70篇
  1977年   46篇
  1976年   47篇
  1975年   21篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
A pulmonary artery (PA) sling is a very rare congenital cardiovascular anomaly, and only a few studies have reported PA slings in fetuses. The relationship of the PA, aorta, ductus arteriosus, and trachea can be evaluated in the 3‐vessel and 3‐vessel and trachea views during fetal echocardiography. A PA sling can be detected by abnormal positioning of the left PA in relation to the trachea when sweeping from the 3‐vessel view cranially to the 3‐vessel and trachea view. Here we report 3 cases of fetal PA slings and their follow‐ups. Two cases were confirmed by postnatal echocardiography, and the other case was confirmed by a cardiovascular cast after pregnancy termination. We emphasize that the 3‐vessel and 3‐vessel and trachea views are of crucial importance in the prenatal diagnosis of a PA sling.  相似文献   
32.
33.
目的 依据髌周解剖学特点,探讨全膝关节置换术(total knee arthroplasty,TKA)中应用髌周电灼去神经化的临床效果。 方法 纳入82名诊断为骨性关节炎的患者(91膝),予行双侧或单侧不置换髌骨的TKA,按随机对照原则将病人分为两组,共有41名实验组患者(45膝)在TKA中接受了髌周去神经化处理,41名对照组患者(46膝)未做该处理。手术主刀为同一骨科医师,均使用相同的膝关节假体系统。主要评价项目包括膝关节KSS评分、Western Ontario and McMaster Universities(WOMAC)、Feller髌骨评分及VAS评分。 结果 82名患者术后均获随访,平均随访时间为12个月,两组病人的膝关节KSS评分、WOMAC、Feller髌骨评分及VAS评分均无显著统计学差异(P>0.05)。 结论 在TKA中行髌周电灼去神经化,不能显著改善病人的预后。  相似文献   
34.

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   
35.
36.
37.
38.
PurposeTo investigate dynamic variables obtained from retrospective computed tomography angiography for ability to predict thoracic endovascular aortic repair (TEVAR) outcomes in patients with complicated type B aortic dissection (cTBAD).Materials and MethodsSeventy-nine patients with cTBAD who received TEVAR from March 2009 to June 2018 were retrospectively enrolled. Relative true lumen area (r-TLA) was computed at the level of tracheal bifurcation every 5% of all R-R intervals. Parameters that reflect the state of intimal motion were evaluated, including difference between maximum and minimum r-TLA (D-TLA) and true lumen collapse. The endpoints comprised early (≤ 30 days) and late (> 30 days) outcomes after intervention.ResultsOverall early mortality rate was 13.9% (11/79), and early adverse events rate was 24.1% (19/79). Patients who received TEVAR within 2 days of symptom onset demonstrated the worst outcomes. A longer time of r-TLA < 25% in 1 cardiac cycle (P = .049) and larger D-TLA (P < .001) were correlated to an increased early death. In addition, D-TLA was an independent predictor of early mortality. Area under the curve of D-TLA was 0.849 (95% confidence interval 0.730–0.967) for predicting early mortality and 0.742 (95% CI 0.611–0.873) for predicting early adverse events. Survival and event-free survival rates during follow-up were decreased in the D-TLA > 21.5% group compared with the D-TLA ≤ 21.5% group (all P < .001).ConclusionsLarger D-TLA is correlated with worse postoperative outcomes and might be a crucial parameter for future risk stratification in patients with cTBAD.  相似文献   
39.
40.
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