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   5157篇
  免费   290篇
  国内免费   110篇
耳鼻咽喉   26篇
儿科学   15篇
妇产科学   3篇
基础医学   262篇
口腔科学   424篇
临床医学   400篇
内科学   889篇
皮肤病学   68篇
神经病学   86篇
特种医学   151篇
外科学   1982篇
综合类   835篇
预防医学   90篇
眼科学   28篇
药学   213篇
  3篇
中国医学   53篇
肿瘤学   29篇
  2024年   19篇
  2023年   134篇
  2022年   131篇
  2021年   261篇
  2020年   249篇
  2019年   185篇
  2018年   207篇
  2017年   171篇
  2016年   154篇
  2015年   180篇
  2014年   323篇
  2013年   363篇
  2012年   246篇
  2011年   287篇
  2010年   262篇
  2009年   250篇
  2008年   259篇
  2007年   262篇
  2006年   221篇
  2005年   212篇
  2004年   194篇
  2003年   183篇
  2002年   138篇
  2001年   134篇
  2000年   88篇
  1999年   66篇
  1998年   59篇
  1997年   42篇
  1996年   41篇
  1995年   33篇
  1994年   34篇
  1993年   22篇
  1992年   25篇
  1991年   17篇
  1990年   19篇
  1989年   15篇
  1988年   21篇
  1987年   9篇
  1986年   10篇
  1985年   6篇
  1984年   6篇
  1982年   3篇
  1981年   4篇
  1980年   1篇
  1978年   5篇
  1977年   5篇
  1976年   1篇
排序方式: 共有5557条查询结果,搜索用时 15 毫秒
81.
82.
目的:探讨冠状动脉搭桥术后监护。方法:回顾性分析55例冠状动脉搭桥患者术后监护资料。结果:55例患者中,2例死亡,病死率3.6%;8例出现并发症,发生率14.55%。结论:冠状动脉搭桥术后加强循环系统、呼吸系统等监护措施,加强基础护理,可降低并发症,提高手术治愈率。  相似文献   
83.
Abstract

Objectives. Plasma hyaluronan and syndecan-1 levels represent shedding of the endothelium glycocalyx during ischemia and edema. Diazoxide, a KATP-channel opener, has been shown to decrease myocardial edema during coronary artery bypass grafting (CABG). We evaluated whether Diazoxide exerts an impact on plasma hyaluronan and syndecan-1 levels during CABG. Design. Representative blood samples for hyaluronan and syndecan-1, before, during and after surgery, were obtained in 13 out of 16 patients that had a history of stable coronary artery disease undergoing CABG with or without Diazoxide. Electron microscopy from biopsies procured from the right atrium in 9 patients was performed to confirm ultrastructural differences among patients before and during CABG. Results. Ultrastructural differences were apparent between individual patients already before operation at base line reflecting differences in the severity of myocardial ischemia and edema. A significant decrease of hyaluronan and syndecan-1 values was observed in patients with Diazoxide after surgery (p < 0.04). Significant correlation of Plasma hyaluronan and syndecan-1 levels was observed in patients with Diazoxide but not in controls (p < 0.005, Spearman rank rho). Conclusion. Diazoxide may have an impact on levels of peripheral plasma hyaluronan and syndecan-1 after CABG, suggesting decreased shedding of the endothelial glycocalyx layer.  相似文献   
84.
目的 探讨体外循环冠状动脉搭桥术中常规超滤的应用价值.方法 将60例体外循环冠状动脉搭桥的患者随机分为试验组(n=30)和对照组(n=30).试验组在体外循环中应用持续超滤,对照组作常规体外循环,不应用超滤.两组分别在转流前、主动脉阻断后、转流结束前抽取患者动脉血液样本,测定红细胞压积、血红蛋白、血小板计数、血浆胶体渗透压等指标,并进行术后出血量和输血量的比较.结果 与对照组相比,试验组患者的红细胞压积、血红蛋白、血小板计数、血浆胶体渗透压在转流结束前均有显著提高,术后呼吸机辅助时间缩短、术后出血量减少,差异有统计学意义.结论 体外循环中采用超滤,可有效提高血浆胶体渗透压,减少呼吸机的使用时间;提高红细胞压积、血红蛋白;提高了血小板计数和血浆蛋白的浓度.  相似文献   
85.
Host bone contact of less than 50% is perceived but not proven to cause migration and loosening after actetabular revision. A prospective analysis of cementless acetabular revision cases with impaction grafting was performed to determine if this was an independent risk factor for these events. Sixty-two hips in 54 patients were assessed at a mean follow-up of 84.5 months (range 61–112) yielding a probability of 94.6% of retaining the acetabular component using revision for aseptic loosening as the end point. No single factor was independently causative for loosening, although Type III fixation was associated with migration (p = 0.0159); subanalysis suggested that achieving host–bone contact in at least part of the dome and posterior column is important.  相似文献   
86.
《Acta orthopaedica》2013,84(4):669-674
Four cases of infected non-union of the tibial shaft treated by Küntscher intramedullary reaming and nailing are presented, and on the basis of these cases the indications and prerequisites for the method are discussed.  相似文献   
87.

Objective

To evaluate the cost-effectiveness of using drugeluting stents (DES) compared to bare-metal stents (BMS) for coronary heart disease (CHD).

Data sources/study setting

Data were obtained from the National Health Insurance Longitudinal Health Insurance Database, which contains claims data for 1,000,000 beneficiaries. The data were randomly sampled from all beneficiaries.

Study design

A retrospective claims data analysis.

Data collection/extraction methods

Patients with stable coronary heart disease who underwent coronary stent implantation from 2007 to 2008 were recruited and followed to the end of 2013. After a 2:1 propensity score matched by gender, age, stent number, and the Charlson comorbidity index (CCI), 852 patients with 568 stents in the BMS group and 284 stents in the DES group were included. The cumulative medical costs for both matched groups were estimated with the Kaplan-Meier Sample Average (KMSA), and then the incremental cost-effectiveness ratio (ICER) was estimated.

Principal findings

The ICER of DES vs. BMS was NT$ 663,000 per cardiovascular death averted and NT$ 238,394 per cardiovascular death or coronary event averted in five years from the insurer perspective.

Conclusion

Percutaneous coronary intervention (PCI) with DES was a more cost-effective strategy than PCI with BMS for CHD patients during the five-year follow-up.  相似文献   
88.
BackgroundProsthetic choice for mitral valve replacement is generally driven by patient age and patient and surgeon preference, and current guidelines do not discriminate between different etiologies of mitral valve disease. Our objective was to assess and compare short- and long-term outcomes after mitral valve replacement among patients with biological or mechanical prostheses in the setting of severe ischemic mitral regurgitation.MethodsBetween 2000 and 2016, 424 patients underwent mitral valve replacement for severe ischemic mitral regurgitation at our institution, using biological prosthesis in 188 (44%) and mechanical prosthesis in 236 (56%). A 1:1 propensity score match (n = 126 per group) and inverse probability of treatment weighting were used to compare groups. Short-term outcomes included in-hospital mortality and other cardiovascular adverse events. Long-term outcomes included survival and hospital readmission for cardiovascular causes, stroke, and major bleeding.ResultsIn-hospital mortality and early postoperative adverse events were similar between groups in the propensity score match and inverse probability of treatment weighting cohorts. Overall long-term survival was similar at 5 and 9 years, but mechanical prosthesis recipients were more frequently readmitted to hospital for cardiovascular causes, including stroke and non-neurological bleeding in propensity score matching and inverse probability of treatment weighting analyses (all P values < .004). Type of prosthesis did not independently influence all-cause mortality (hazard ratio, 1.01; 95% confidence interval, 0.71-1.43; P = .959), but placement of a mechanical prosthesis was associated with increased risk of readmission for cardiovascular events (hazard ratio, 1.65; 95% confidence interval, 1.17-2.32; P = .004) among matched patients.ConclusionsThe type of prosthesis has no influence on long-term survival among patients with severe ischemic mitral regurgitation undergoing mitral valve replacement. There may be an increased risk of neurologic events and serious bleeding associated with mechanical prostheses.  相似文献   
89.
 We report a case of coronary artery bypass grafting (CABG) using the left internal mammary artery (LIMA) and a saphenous vein graft in a 36-year-old man with Buerger's disease. He was hospitalized in the coronary intensive care unit with a diagnosis of acute myocardial infarction. His coronary angiography showed total occlusion of the proximal segment of the left anterior descending artery (LAD) and right coronary artery. Left ventricular dysfunction was detected by ventriculography. The patient had undergone bilateral sympathectomy of the lumbar branches for distal arterial occlusions due to thromboangiitis obliterans 12 years previously. Under cardiopulmonary bypass and aortic cross-clamping, we performed endarterectomy and a complex bypass procedure to LAD. Aorta-right coronary artery bypass was also applied. A histopathological study of an endarterectomy specimen showed characteristic features of thromboangiitis obliterans. The postoperative course was uneventful and the patient was discharged on the ninth postoperative day. Received: November 19, 2001 / Accepted: February 16, 2002  相似文献   
90.
Objective: The role of coronary artery bypass grafting (CABG) in patients with severe left ventricular dysfunction was evaluated. Methods: Two hundred and twelve patients (152 men, 60 women; age 35 to 82, mean 55) with ejection fraction (EF) of less than 30% underwent CABG between January 1996 and February 2001 by a single surgeon (SA). They compromised of 12% of 1759 patients operated on in this period. EF ranged from 17% to 30% (mean 25%). Preoperatively 68% had congestive heart failure and 72% had severe angina (CCS 3 or 4). A left main lesion was found in 26% of the cases. The mean number of grafts was 3.18 per patient. The left internal mammary artery (LIMA) was used on 107 patients (50.4%). Preoperative intraaortic balloon pump (IABP) was used on 32 patients (15%). Endarterectomy was performed on 53 patients (25%). The patients were followed for up to 58 months (mean 28.7). Results: Twelve patients died in hospital (5.6%). Survival was 94%, 87%, 80% and 73% at 1, 2, 3 and 4 years respectively. Among the preoperative variables survival was negatively affected by chronic renal failure, older age, congestive heart failure, elevated pulmonary artery pressure and recent myocardial infarction, by means of multivariate analysis. Preoperative IABP support improved the operative mortality significantly (P=0.002). Use of LIMA did not have any influence on survival. Conclusion: CABG on patients with poor left ventricular function: (1) Can be performed with an acceptable mortality. (2) Mid term results are encouraging. (3) Preoperative IABP support improves the chance of survival.  相似文献   
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