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   232788篇
  免费   12843篇
  国内免费   6598篇
耳鼻咽喉   2793篇
儿科学   8413篇
妇产科学   3301篇
基础医学   17616篇
口腔科学   4423篇
临床医学   28377篇
内科学   41640篇
皮肤病学   3109篇
神经病学   11029篇
特种医学   12508篇
外国民族医学   22篇
外科学   37810篇
综合类   21211篇
现状与发展   25篇
预防医学   15028篇
眼科学   4444篇
药学   24471篇
  95篇
中国医学   4657篇
肿瘤学   11257篇
  2023年   2204篇
  2022年   4203篇
  2021年   9634篇
  2020年   6076篇
  2019年   11828篇
  2018年   6461篇
  2017年   5411篇
  2016年   7395篇
  2015年   10290篇
  2014年   18804篇
  2013年   16480篇
  2012年   19516篇
  2011年   16406篇
  2010年   15057篇
  2009年   14611篇
  2008年   13159篇
  2007年   13157篇
  2006年   11124篇
  2005年   7412篇
  2004年   3845篇
  2003年   3326篇
  2002年   2709篇
  2001年   2113篇
  2000年   1910篇
  1999年   1169篇
  1998年   1580篇
  1997年   1407篇
  1996年   1203篇
  1995年   1268篇
  1994年   1211篇
  1993年   940篇
  1992年   1169篇
  1991年   1007篇
  1990年   1058篇
  1989年   1037篇
  1988年   976篇
  1987年   857篇
  1986年   697篇
  1985年   1601篇
  1984年   1754篇
  1983年   1263篇
  1982年   1357篇
  1981年   1341篇
  1980年   1156篇
  1979年   995篇
  1978年   760篇
  1977年   765篇
  1976年   666篇
  1975年   435篇
  1974年   454篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
IntroductionOur aim was to describe practices in multimodal pain management at US children's hospitals and evaluate the association between non-opioid pain management strategies and pediatric patient-reported outcomes (PROs).MethodsData were collected as part of the 18-hospital ENhanced Recovery In CHildren Undergoing Surgery (ENRICH-US) clinical trial. Non-opioid pain management strategies included use of preoperative and postoperative non-opioid analgesics, regional anesthetic blocks, and a biobehavioral intervention. PROs included perioperative nervousness, pain-related functional disability, health-related quality of life (HRQoL). Associations were analyzed using multinomial logistic regression models.ResultsAmong 186 patients, 62 (33%) received preoperative analgesics, 186 (100%) postoperative analgesics, 81 (44%) regional anesthetic block, and 135 (73%) used a biobehavioral intervention. Patients were less likely to report worsened as compared to stable nervousness following regional anesthetic block (relative risk ratio [RRR]:0.31, 95% confidence interval [CI]:0.11–0.85), use of a biobehavioral technique (RRR:0.26, 95% CI:0.10–0.70), and both in combination (RRR:0.08, 95% CI:0.02–0.34). There were no associations of non-opioid pain control modalities with pain-related functional disability or HRQoL.ConclusionUse of postoperative non-opioid analgesics have been largely adopted, while preoperative non-opioid analgesics and regional anesthetic blocks are used less frequently. Regional anesthetic blocks and biobehavioral interventions may mitigate postoperative nervousness in children.Level of evidenceIII.  相似文献   
2.
认知障碍是指记忆、语言、理解和判断等一个或多个方面的功能障碍,包括轻度认知障碍和各种类型的痴呆症。痴呆症是认知障碍最严重的表现,是一种导致患者日常生活、社会交往和工作能力发生显著变化的综合征。阿尔茨海默病(AD)是最常见的痴呆症类型,其次是血管性痴呆(VD)和其他神经退行性痴呆[1]。已知年龄与认知功能的退化密切相关。  相似文献   
3.
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area.  相似文献   
4.
温婷  刘汉娇  易云霞 《全科护理》2022,20(2):199-202
综述女性压力性尿失禁(stress urinary incontinence,SUI)风险预测的研究进展。指出女性SUI风险预测相关文献普遍存在风险预测工具和指标缺乏临床大样本验证,指标、纳入人群不统一的现象,风险预测模型存在构建过程未按报告规范进行,未进行完整的模型验证以及模型性能评价指标不规范的情况。未来研究可以在现有风险预测工具或模型的基础上进行改进、完善,以期为女性SUI风险预测提供参考。  相似文献   
5.
BackgroundPost-operative elderly hip fracture patients require significant rehabilitation. Nandrolone is an anabolic steroid used to promote muscle growth. This study aims to examine the effect of nandrolone in improving rehabilitation and quality of life in elderly female patients with hip fractures undergoing hemiarthroplasty.MethodsThis is a double-blinded prospective randomized-controlled-trial consisting of female patients above the age of 65 with an isolated neck of femur fracture planned for a hip hemiarthroplasty. Participants were randomized into two arms of the study – 50 mg intramuscular nandrolone vs normal saline placebo administered on post-operative day 0, and weeks 2, 6 and 12. The participants were followed up across a 1-year period following the surgery. Clinical outcomes such as time taken to achieve rehabilitation milestones, distance of ambulation and thigh muscle girth, and functional scoring with SF-36 questionnaire were recorded at intervals of 2, 6 and 12 weeks, 6 months and 1 year following the surgery.ResultsThere were a total of 23 subjects with 11 in the steroid group and 12 in the placebo group. There was no significant difference in demographics and injury patterns between both groups. There was no significant difference for time taken to achieve various rehabilitation milestones and distance of ambulation. SF-36 scores on discharge and at 1-year follow-up mark were comparable. There was no difference in the complication rate between both groups.ConclusionIntra-muscular Nandrolone after hip surgery in elderly female patients does not result in short to mid-term improved rehabilitation or functional outcomes. Nandrolone did not result in increased short-term complications after hip surgery.Level of evidenceI.  相似文献   
6.
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.  相似文献   
7.
ObjectiveDeterioration of the native aortic valve function by a late progression of rheumatic disease is not infrequent in patients who underwent rheumatic mitral valve surgery; however, this phenomenon has not been clearly quantified.MethodsA total of 1155 consecutive patients (age 52.0 ± 12.9 years; 807 female) who underwent rheumatic mitral valve surgery without concomitant aortic valve surgery from 1997 to 2015 were enrolled. The primary end point was the composite of progression to severe aortic valve dysfunction or a requirement of subsequent aortic valve replacements during follow-up. To determine the risk factors of the primary outcome, we performed the generalized linear mixed model.ResultsThe baseline severities of aortic valve were none to trivial in 880 patients (76.2%), mild in 256 patients (22.2%), and moderate in 19 patients (1.6%). The latest 1062 echocardiographic assessments (91.9%; median, 81.2 postoperative months; interquartile range, 37.3-132.1 months) demonstrated 26 cases (0.33%/patient-year) meeting the primary end point during follow-up. Cumulative incidence of the primary end point at 10 years was 0.4% ± 0.3% and 7.4% ± 2.5% depending on the presence of mild or greater aortic valve dysfunction at baseline (P < .01). In multivariable analyses, aortic valve peak pressure gradient (odds ratio, 1.14; 95% confidence interval, 1.10-1.20), aortic regurgitation degree (mild over none: odds ratio, 3.26; 95% confidence interval, 1.15-9.23), and time (odds ratio, 1.30; 95% confidence interval 1.19-1.41) were significantly associated with the occurrence of the primary end point.ConclusionsProgression of severe aortic valve dysfunction and the need for aortic valve replacement are uncommon in patients undergoing rheumatic mitral valve surgery. However, such events were relatively common among those with mild or greater aortic valve dysfunction at the time of mitral valve surgery.  相似文献   
8.
9.
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