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   46580篇
  免费   3079篇
  国内免费   1534篇
耳鼻咽喉   672篇
儿科学   1105篇
妇产科学   676篇
基础医学   5129篇
口腔科学   912篇
临床医学   4682篇
内科学   6941篇
皮肤病学   1981篇
神经病学   2815篇
特种医学   1656篇
外国民族医学   3篇
外科学   1911篇
综合类   6425篇
现状与发展   6篇
预防医学   5126篇
眼科学   564篇
药学   6544篇
  28篇
中国医学   2173篇
肿瘤学   1844篇
  2024年   70篇
  2023年   549篇
  2022年   1140篇
  2021年   1630篇
  2020年   1452篇
  2019年   1327篇
  2018年   1376篇
  2017年   1383篇
  2016年   1430篇
  2015年   1564篇
  2014年   2825篇
  2013年   3201篇
  2012年   2860篇
  2011年   3035篇
  2010年   2426篇
  2009年   2285篇
  2008年   2303篇
  2007年   2411篇
  2006年   2047篇
  2005年   1871篇
  2004年   1546篇
  2003年   1383篇
  2002年   1134篇
  2001年   1039篇
  2000年   855篇
  1999年   817篇
  1998年   651篇
  1997年   662篇
  1996年   590篇
  1995年   568篇
  1994年   494篇
  1993年   401篇
  1992年   434篇
  1991年   398篇
  1990年   324篇
  1989年   335篇
  1988年   313篇
  1987年   286篇
  1986年   236篇
  1985年   264篇
  1984年   204篇
  1983年   165篇
  1982年   185篇
  1981年   141篇
  1980年   128篇
  1979年   90篇
  1978年   81篇
  1977年   68篇
  1976年   48篇
  1975年   38篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
《Urological Science》2015,26(2):144-146
Hydronephrosis with an undetermined pathology is a common condition detected in imaging studies. In urological clinical practice, it is a persistent dilemma to predict whether this condition will progress to result in the deterioration of renal function. Perfusion pressure flow study of the upper urinary tract, known as the Whitaker test, provides an alternative diagnostic tool for solving this condition. Perfusion pressure flow study has been criticized for its invasiveness, nonphysiological approach, and inconsistency in predicting outcomes. However, it continues to be used to evaluate difficult or equivocal cases and to provide an objective assessment of the upper urinary tract.  相似文献   
5.
胡山  赵波 《中国临床医学》2020,27(3):899-900
面对来势汹汹的新型冠状病毒肺炎(COVID-19),如何能够正确、快速诊断和筛检出确诊病例显得尤为重要,国内诸多科技工作者都在积极开展相关的诊断试验研究。本文回顾了目前正在开展的十余项诊断试验的注册信息,针对其中存在的共性问题进行了讨论,重点阐述了如何使用PICOS原则构造COVID-19诊断试验的研究问题,还对金标准的设置、受试者的代表性、样本量计算和同步、独立、盲法的测定等诊断试验的设计要点进行了详细说明。旨在为广大研究者提供开展COVID-19诊断试验的设计建议,帮助研究者在顶层设计阶段减少、避免偏倚,完成高质量的临床研究,为临床诊疗提供循证医学证据。  相似文献   
6.

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   
7.
A survey of mycology laboratories for antifungal susceptibility testing (AFST) was undertaken in France in 2018, to better understand the difference in practices between the participating centers and to identify the difficulties they may encounter as well as eventual gaps with published standards and guidelines. The survey captured information from 45 mycology laboratories in France on how they perform AFST (number of strains tested, preferred method, technical and quality aspects, interpretation of the MIC values, reading and interpretation difficulties). Results indicated that 86% of respondents used Etest as AFST method, with a combination of one to seven antifungal agents tested. Most of the participating laboratories used similar technical parameters to perform their AFST method and a large majority used, as recommended, internal and external quality assessments. Almost all the participating mycology laboratories (98%) reported difficulties to interpret the MIC values, especially when no clinical breakpoints are available. The survey highlighted that the current AFST practices in France need homogenization, particularly for MIC reading and interpretation.  相似文献   
8.
9.
ObjectivesGrowing evidence of the importance of motor competence for developing a healthy lifestyle has been established in the last decade. Nonetheless, no single instrument or observation tool have been able to fully measure this construct, particularly because most were built for the diagnosis of children in risk for motor impairment; are limited to a few years of the developmental span; lack objectivity in the assessment protocols; or do not include the locomotor, stability, and manipulative components. This led to the difficulty of comparing researches, and longitudinally follow children into adulthood. Recently, a novel proposal to assess motor competence was presented - the Motor Competence Assessment (MCA) - and this study aims to present the MCA normative data from 3-to-23 years.Design and methodsTwo thousand and eighty-seven participants (1102 boys) between 3 and 23 years of age were evaluated in the MCA (standing long jump, 10 m shuttle run, throwing velocity, kicking velocity, lateral jumps, shifting platforms). Results for each test were introduced in the LMS Chartmaker 2.3. The best model for test and sex was used, resulting in normative curves and percentile values.ResultsFinal norms showed a good fit to the instrument developmental expectations, allowing to differentiate and classify performances along the age interval.ConclusionsThe MCA age- and sex- normative values allow to assess motor competence from childhood to early adulthood. Future directions will include obtaining a total MCA score and the normative scores for the MCA components (stability, locomotion, object control), and to expand the norms to adulthood and old age.  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