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   76419篇
  免费   6138篇
  国内免费   2882篇
耳鼻咽喉   432篇
儿科学   1182篇
妇产科学   478篇
基础医学   4273篇
口腔科学   1662篇
临床医学   10326篇
内科学   25013篇
皮肤病学   1214篇
神经病学   1954篇
特种医学   3198篇
外科学   4620篇
综合类   13854篇
现状与发展   15篇
一般理论   4篇
预防医学   6707篇
眼科学   939篇
药学   5528篇
  63篇
中国医学   3399篇
肿瘤学   578篇
  2024年   221篇
  2023年   1461篇
  2022年   2824篇
  2021年   3778篇
  2020年   3534篇
  2019年   2740篇
  2018年   2725篇
  2017年   2392篇
  2016年   2686篇
  2015年   2601篇
  2014年   5274篇
  2013年   5440篇
  2012年   4542篇
  2011年   4931篇
  2010年   3989篇
  2009年   3779篇
  2008年   3827篇
  2007年   3992篇
  2006年   3358篇
  2005年   3024篇
  2004年   2376篇
  2003年   2068篇
  2002年   1742篇
  2001年   1633篇
  2000年   1258篇
  1999年   1020篇
  1998年   1053篇
  1997年   986篇
  1996年   703篇
  1995年   763篇
  1994年   614篇
  1993年   521篇
  1992年   476篇
  1991年   425篇
  1990年   334篇
  1989年   328篇
  1988年   317篇
  1987年   288篇
  1986年   225篇
  1985年   241篇
  1984年   187篇
  1983年   120篇
  1982年   131篇
  1981年   108篇
  1980年   76篇
  1979年   85篇
  1978年   46篇
  1977年   56篇
  1976年   44篇
  1975年   38篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
姚海艳  史珣瑜  施江 《全科护理》2021,19(4):566-569
目的:探讨经皮冠状动脉介入(PCI)术后病人的体力活动水平及其影响因素。方法:选择常州市三级甲等综合医院心内科接受PCI治疗的冠心病病人,收集资料,分析PCI术后冠心病病人体力活动动机、体力活动和自我效能现状;冠心病病人自我效能、体力活动动机与体力活动的相关性,并分析影响PCI术后病人体力活动水平的相关危险因素。结果:共发放调查问卷400份,回收400份,有效率为94.75%(379/400);379例冠心病病人术后每周体力活动为(3570.85±314.19)MET-min,以低、中强度为主;冠心病病人术后自我效能总分、体力活动动机总分与体力活动呈正相关(P<0.05);体质指数(BMI)、PCI次数≥2次、年龄、PCI支架数量≥3枚、自我效能、体力活动动机是影响PCI术后冠心病病人体力活动水平的高危因素(OR>1且P<0.05)。结论:PCI术后病人体力活动水平处于较低的水平,PCI次数、BMI、年龄、PCI支架数量、自我效能、体力活动动机是影响PCI术后冠心病病人体力活动水平的高危因素,临床需针对各高危因素制定相应的干预措施,提高病人体力活动水平。  相似文献   
3.
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   
4.
5.
6.
??Objective    To discuss the influence of basic periodontal therapy on the level of IL-8?? IL-10 in serum and gingival crevicular fluid in patients who have chronic periodontitis complicated by coronary heart disease. Methods     A total of 65 cases of patients with chronic periodontitis complicated by coronary heart disease were selected and divided into two groups randomly??Group A of 35 patients who received the basic periodontal therapy and cardiac medical treatment??Group B of 30 patients who received cardiological treatment only. Then??select 25 patient who had developed chronic severe periodontitis with non-systematic disease to establish group C and give them the basic periodontal therapy only. Observe the changes of the IL-8??IL-10 levels in serum and gingival crevicular fluid and the periodontal infection indexes??BI??PD??. Results    The results showed that after three months of basic periodontal therapy the periodontal clinical indices of both group A and group C became better and the IL-8 level obviously reduced??while the IL-10 level obviously increased. There was no obvious difference between group A and group B in each examination index before the therapy. After three months??we found that the periodontal infection index??SBI PD??of group A was obviously better than group B. Compared to group B??the IL-8 level of group A obviously reduced??and the IL-10 level obviously increased. The difference was statistically significant??P < 0.05??. Conclusion    The basic periodontal therapy can effectively improve periodontal conditions of the patients with chronic periodontal diseases??and reduce the risk of breaking the normal cardiovascular function.  相似文献   
7.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
8.
宫颈癌对妇女健康构成严重威胁,人乳头瘤病毒感染与宫颈病变及宫颈癌的发生密切相关。关于宫颈癌发生发展的机制仍在研究中。近年研究发现一种多功能核蛋白,即死亡结构域相关蛋白(death domain associated protein,Daxx),其与细胞内蛋白或病毒蛋白相互作用,参与调节细胞凋亡、转录调控、抗病毒等细胞活动,在不同途径中发挥不同的生理或病理作用。通过对Daxx功能及其作用机制的研究有助于进一步阐明宫颈癌发生发展的机制,有助于发现新的预防和治疗方法。综述Daxx的一般特性和研究现况及其在宫颈病变的研究进展。  相似文献   
9.
《Australian critical care》2019,32(6):540-559
ObjectivesThe objective of this review was to describe cardiovascular risk (CVR) assessment methods and to identify evidence-based practice recommendations when dealing with population at risk of developing cardiovascular diseases.Review methods and data sourcesA literature review following the Arksey and O'Malley scoping review methodology was conducted. By using appropriate key terms, literature searches were conducted in PubMed, SciELO, Cochrane Library, Dialnet, ENFISPO, Medigraphic, ScienceDirect, Cuiden, and Lilacs databases. A complementary search on websites related to the area of interest was conducted. Articles published in English or Spanish in peer-review journals between 2010 and 2017. Critical appraisal for methodological quality was conducted. Data was extracted using ad-hoc tables and qualitatively synthesized.ResultsAfter eliminating duplicates, 55 325 records remained, and 1432 records were selected for screening. Out of these, 88 full-text articles were selected for eligibility criteria, and finally, 67 studies were selected for this review, and 25 studies were selected for evidence synthesis. In total, 23 CVR assessment tools have been identified, pioneered by the Framingham study. Qualitative findings were grouped into four thematic areas: assessment tools and scores, CVR indicators, comparative models, and evidence-based recommendations.ConclusionsIt is necessary to adapt the instruments to the epidemiological reality of the population. The most appropriate way to estimate CVR is to choose the assessment tool that best suits individual conditions, accompanied by a comprehensive assessment of the patient. More research is required to determine a single, adequate, and reliable tool.  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