全文获取类型
收费全文 | 134142篇 |
免费 | 9909篇 |
国内免费 | 3146篇 |
专业分类
耳鼻咽喉 | 3103篇 |
儿科学 | 2989篇 |
妇产科学 | 2071篇 |
基础医学 | 6087篇 |
口腔科学 | 3283篇 |
临床医学 | 15299篇 |
内科学 | 25758篇 |
皮肤病学 | 757篇 |
神经病学 | 3401篇 |
特种医学 | 3005篇 |
外国民族医学 | 20篇 |
外科学 | 30132篇 |
综合类 | 21813篇 |
现状与发展 | 10篇 |
一般理论 | 5篇 |
预防医学 | 5308篇 |
眼科学 | 4589篇 |
药学 | 8917篇 |
240篇 | |
中国医学 | 4758篇 |
肿瘤学 | 5652篇 |
出版年
2024年 | 156篇 |
2023年 | 2824篇 |
2022年 | 3548篇 |
2021年 | 6250篇 |
2020年 | 6591篇 |
2019年 | 5589篇 |
2018年 | 5348篇 |
2017年 | 4821篇 |
2016年 | 4705篇 |
2015年 | 4814篇 |
2014年 | 9824篇 |
2013年 | 9569篇 |
2012年 | 7770篇 |
2011年 | 8232篇 |
2010年 | 6514篇 |
2009年 | 6199篇 |
2008年 | 5995篇 |
2007年 | 6199篇 |
2006年 | 5364篇 |
2005年 | 4862篇 |
2004年 | 4074篇 |
2003年 | 3471篇 |
2002年 | 2908篇 |
2001年 | 2703篇 |
2000年 | 2259篇 |
1999年 | 2161篇 |
1998年 | 1818篇 |
1997年 | 1741篇 |
1996年 | 1255篇 |
1995年 | 1172篇 |
1994年 | 1114篇 |
1993年 | 874篇 |
1992年 | 790篇 |
1991年 | 738篇 |
1990年 | 562篇 |
1989年 | 538篇 |
1988年 | 480篇 |
1987年 | 464篇 |
1986年 | 398篇 |
1985年 | 445篇 |
1984年 | 403篇 |
1983年 | 245篇 |
1982年 | 279篇 |
1981年 | 246篇 |
1980年 | 205篇 |
1979年 | 150篇 |
1978年 | 132篇 |
1977年 | 111篇 |
1976年 | 94篇 |
1975年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
1.
2.
采用Mimics对心脏进行三维重构,用3-matic进行模型优化以及模型误差分析,对左心室室壁运动做速度分布假设,基于UDF宏文件对左心室室壁运动编写程序,将血液视为非牛顿流体,采用动网格技术研究不同血压对左心室血液流动的影响。模拟发现当左心室收缩时,压力梯度明显,内部压力减小。当左心室舒张时,内部压力逐渐增高。二尖瓣口处的速率先增大后减小。血压升高,左心室内剪切应力持续增大,极易破坏红细胞结构,产生溶血现象,导致心脏功能紊乱。 相似文献
3.
4.
目的探讨衰减伪影对冠心病患者门控心肌灌注显像(GMPI)图像质量及灌注结果的影响。资料与方法回顾性分析2020年3月—2021年3月在郑州大学第一附属医院核医学科经冠状动脉造影证实且于造影前后1周行GMPI的99例冠心病患者的图像,定性及半定量分析衰减校正前后GMPI图像结果,比较衰减校正前后左心室各壁段平均放射性计数及灌注结果的差异,进一步分析衰减校正前后灌注结果不一致部分的受检者的节段性室壁运动及增厚情况。结果与衰减校正前比较,衰减校正后左心室间隔、下后壁及侧壁的平均放射性计数较高(Z=-7.302、-8.014、-3.991,P均<0.001),心尖部较低(Z=-8.021,P<0.001)。其中女性衰减校正后前壁平均放射性计数减低(Z=-2.314,P=0.021)。男性衰减校正前后下后壁放射性计数差值明显高于女性(t=-8.408,P<0.05)。衰减校正后44%(44/99)的左前降支及37%(37/99)的右冠状动脉分支供血区域显像结果发生改变,结合超声心动图及GMPI结果显示其中85%(35/41)的左前降支及81%(29/36)的右冠状动脉分支供血区域室壁运动及室壁增厚率均正常。结论衰减伪影对GMPI的图像质量和灌注结果有较大影响,结合室壁运动和增厚情况等有助于鉴别衰减伪影,提高诊断准确度与特异度。 相似文献
5.
《Cirugía espa?ola》2022,100(3):149-153
IntroductionThe Law for the Regulation of Health Professions (LOPS) indicates that health professionals will carry out continuous training throughout their professional life, and will regularly prove their professional competence. The objective of the study was to carry out a national survey to find out the opinion of Spanish surgeons and thus be able to prepare a recertification project by the Spanish Association of Surgeons (AEC).MethodsCross-sectional observational study carried out in June-July 2020, through a survey sent to the members of the AEC.ResultsThe survey had a total of 1230 visits and an overall completion rate of 784 responses (67.3%). 69.6% were unaware of the LOPS forecasts and 83.4% were unaware of similar initiatives in other specialties and 95.5% agreed to demand adequate information. 71.4% believed it necessary but only 57% believed that it should be mandatory. 82.9% would agree that it should be regulated through an objective and predictable official procedure.ConclusionsThe concept of re-accreditation is not well known in our specialty and in view of the results obtained, adequate and reliable information seems necessary. Therefore, it would be pertinent to propose by the AEC a specific project to assess activities and skills. 相似文献
6.
Mette Nissen Tiina‐Mari Ikheimo Jukka Huttunen Ville Leinonen Henna‐Kaisa Jyrkknen Mikael von und zu Fraunberg 《Neuromodulation》2021,24(1):102-111
ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation. 相似文献
7.
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
8.
9.
Kara S. Tanaka MD Veronica R. Andaya BA Steven W. Thorpe MD Kenneth R. Gundle MD James B. Hayden MD Yee-Cheen Duong MD Raffi S. Avedian MD David G. Mohler MD Lee J. Morse MD Melissa N. Zimel MD Richard J. O'Donnell MD Andrew Fang MD Robert Lor Randall MD Tina H. Tran BS Christin New BA Rosanna L. Wustrack MD other members of Study Group FORCE 《Journal of surgical oncology》2023,127(1):148-158
10.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):94-103.e24
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