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   2553篇
  免费   46篇
  国内免费   19篇
耳鼻咽喉   2篇
儿科学   86篇
妇产科学   9篇
基础医学   116篇
口腔科学   1篇
临床医学   596篇
内科学   945篇
神经病学   23篇
特种医学   65篇
外科学   469篇
综合类   210篇
预防医学   32篇
药学   61篇
  1篇
中国医学   2篇
  2023年   54篇
  2022年   99篇
  2021年   129篇
  2020年   88篇
  2019年   67篇
  2018年   97篇
  2017年   50篇
  2016年   49篇
  2015年   53篇
  2014年   166篇
  2013年   124篇
  2012年   90篇
  2011年   131篇
  2010年   92篇
  2009年   120篇
  2008年   115篇
  2007年   117篇
  2006年   120篇
  2005年   80篇
  2004年   80篇
  2003年   65篇
  2002年   66篇
  2001年   56篇
  2000年   69篇
  1999年   57篇
  1998年   45篇
  1997年   49篇
  1996年   37篇
  1995年   39篇
  1994年   30篇
  1993年   27篇
  1992年   24篇
  1991年   14篇
  1990年   14篇
  1989年   10篇
  1988年   10篇
  1987年   11篇
  1986年   7篇
  1985年   6篇
  1984年   11篇
  1983年   5篇
  1982年   12篇
  1981年   5篇
  1980年   4篇
  1979年   3篇
  1978年   5篇
  1977年   2篇
  1976年   7篇
  1975年   2篇
  1973年   2篇
排序方式: 共有2618条查询结果,搜索用时 15 毫秒
61.
62.
We describe a patient who underwent radiofrequency (RF) catheter ablation of symptomatic atrial fibrillation. After left atrial (LA) catheter ablation and pulmonary vein isolation, a macro-reentrant atrial tachycardia (AT) with a critical isthmus at the mitral isthmus was induced by incremental atrial pacing from the coronary sinus. Extensive RF energy applications from endocardial sites using ablation catheters with 4 mm- and 8 mm- tips resulted in no discrete potentials being recorded from the endocardial sites of the isthmus, but the tachycardia could not be terminated. However, discrete potentials were recorded within the CS, and epicardial RF energy applications from the CS eliminated the tachycardia. Thus, mapping in the CS is useful for detecting residual conduction at epicardial sites along the mitral isthmus. RF catheter ablation within the CS should be considered when no distinct electrograms are recorded after extensive ablation from the endocardial sites and when distinct electrograms are recorded within the CS.  相似文献   
63.
Anatomic continuity between the anterior mitral leaflet and the aortic root may predispose those patients with aortic root pathology to functional changes of the mitral valve without any involvement of this valve. A 34-year-old man presented with aortic valve endocarditis. Transthoracic echocardiograpy showed severe aortic regurgitation with a large aortic root abscess. The anterior leaflet of the mitral valve was displaced towards the apex of the heart causing moderate mitral regurgitation. The patient underwent aortic valve replacement with reconstruction of the aortic annulus and ventriculoaortic continuity. This procedure alone restored the mitral valve structure and function without any need for intervention on the mitral valve. Aortic abscess is a serious complication of aortic valve endocarditis and may alter the function of other structures of the heart, especially the mitral valve. Restoration of aortic wall integrity and left ventricular – aortic continuity usually restores the mitral valve structure and function if the valve is unaffected by the infection. A decision on the mitral valve should be made following correction of the aortic pathology.  相似文献   
64.
目的 探讨二尖瓣瓣膜成形术(MVP)治疗非风湿性二尖瓣关闭不全的临床效果.方法 选择2006年1月至2013年11月内蒙古医科大学附属医院非风湿性二尖瓣关闭不全患者43例,病因包括先天性瓣叶脱垂、缺血性改变、退行性改变、感染性病变.手术方式为单纯瓣叶部分切除、单纯腱索短缩或转移、瓣膜裂修补、瓣叶部分切除+双孔成形、腱索短缩或转移+瓣膜裂修补、术中均放置二尖瓣成形环,同期冠状动脉旁路移植术,术中采用注水试验和食管内超声评价成形效果.结果 术前超声心动图示二尖瓣均为中大量关闭不全,术中食管内超声发现中量关闭不全2例,改行二尖瓣置换术.43例患者中术后在院死亡1例.出院后随访1 ~83个月,平均(43±17)个月,无再次手术者,无死亡者,超声心动图示40例二尖瓣瓣膜成形术患者中无或少量二尖瓣关闭不全27例,少量到中量关闭不全13例.结论 应用二尖瓣瓣膜成形术治疗非风湿性二尖瓣关闭不全是可行的,可以取得良好的效果.  相似文献   
65.
In this study we present the results of 105 consecutive patientswith pure mitral regurgitation who underwent surgical treatment.In all patients mitral regurgitation was associated with mitralvalve prolapse: 54 patients underwent mitral valvuloplasty and51 patients mitral valve replacement. Clinical assessment and echocardiography were used as follow-upcriteria at one year after surgery. After mitral valvuloplasty,NYH A decreased from 2.7±0.8 to 1.1±0.7 (P<0.01)and workload capacity increased from 65±28% to 96±25%(P<0.001); left endsystolic atrial dimension and enddiastolicdimension decreased from 6.2±0.8 to 4.8±1.2 cm(P<0.001) and from 7.2±1.3 to 5.9±0.8 cm (P<0.01);ventricular contraction fraction did not change significantly. After mitral valve replacement, clinical and echocardiographicimprovement was significant but less remarkable than after valvuloplasty;ventricular contraction fraction fell from 39±7% to 29±8%in contrast to patients undergoing mitral valvuloplasty in whomno significant change occurred. Complications were rare in both groups though only a minorityof patients undergoing mitral valvuloplasty received anticoagulants.We conclude that mitral valvuloplasty in patients with puremitral regurgitation associated with mitral valve prolapse givesexcellent results, particularly regarding left ventricular functionwhen compared with the patients after mitral valve replacement.  相似文献   
66.
鲁登巴赫综合征的外科治疗   总被引:5,自引:0,他引:5  
目的 :回顾分析 10例鲁登巴赫综合征 ,探讨该疾病在病理生理、诊断和治疗方面的特点。方法 :总结经外科治疗的鲁登巴赫综合征共 10例患者的临床资料。结果 :全组病例无围手术期死亡 ,无顽固性心力衰竭、肺动脉高压危象及恶性心律失常发生。结论 :鲁登巴赫综合征应及早手术治疗 ,修补房间隔缺损同时有效的解除二尖瓣狭窄 ,探查并处理合并的三尖瓣关闭不全 ,术后积极治疗肺动脉高压 ,支持心功能 ,可以取得满意的手术效果  相似文献   
67.
The purpose of this study was to evaluate the characteristicsof mitral annular motion during diastole in 28 normal subjects,40 patients with prior myocardial infarction (MI), and 23 patientswith coronary artery disease but without prior MI. Mitral annularmotion during diastole was obtained from the apex by M-modeechocardiography at the posterior wall of the left ventricle.Determinants of mitral annular excursion during early (MAE-E)and late diastole (MAE-L) were investigated in all subjects.Differences in the MAE-E, MAE-L, and the MAE-L.MAE-E ratio werecompared among the three patient groups. The Doppler-derivedtransmitral flow velocity-time integral during early (El) andlate (AI) diastole and mitral annular excursions during diastolewere obtained in 55 other patients with a prior MI and in 29healthy volunteers. The relationships between the MAE-L: MAE-Eratio and AI: EI ratio in these two groups were studied. The MAE-E was determined mainly by heart rate and left ventricularejection fraction (LVEF). The MAE-L was determined only by age.The magnitude of MAE-E was significantly less in patients witha prior MI than in normal subjects (P<0.01). However, theMAE-L did not differ among the three groups. The MAE-L.MAE-Ewas higher in patients with a prior MI than in normal subjects(P<0.05), and was significantly correlated with AI: EI inhealthy volunteers (r=0.65, P<0.001) and in patients witha prior MI (r=0.50, P<0.001). The MAE-E in patients with a prior MI decreases in proportionto the deterioration in LVEF. The relative at rial contributionto left ventricular longitudinal distension is increased inpatients with a prior MI and diastolic mitral annular motionhas a significant relationship to the transmitral flow. Thesefindings suggest that mitral annular motion during late diastoleplays an important role in maintaining left ventricular fillingin patients whose left ventricular systolic function has deteriorated.  相似文献   
68.
为了减轻二尖瓣关闭不全外科手术和体外循环所带来的创伤和风险,基于外科边对边缝合和瓣环成形的手术方式,近年来二尖瓣关闭不全的介入治疗得到了快速发展,包括经二尖瓣边对边修补术和瓣环成形术,前者经穿房间隔途径送入钳夹装置或负压抽吸缝合装置,钳夹或缝合前后瓣边缘,形成双孔二尖瓣,后者经右颈内静脉途径把缩环装置植入冠状静脉窦内,缩短瓣环前后径,以减轻二尖瓣反流。两种方法均已从动物实验过渡到临床试验,均显示了良好的治疗作用,但还需技术上的进一步改进和长期大规模的临床评价。  相似文献   
69.
对 2 6例二尖瓣狭窄 (MS)合并心房颤动 (Af)患者 ,在行经皮球囊二尖瓣扩张术 (PBMV)前给大剂量肝素短程抗凝 ,并对其中 1 9例在术后即给予同步直流电复律。结果 二尖瓣口面积 (MVA)由 0 92± 0 2cm2 扩大至 1 95± 0 3 7cm2 ,左房平均压 (LAP)由 3 1 2± 1 2 7kPa降至 1 4 2± 0 85kPa,而左房内径 (LAD)由 52 7± 8 1mm缩小至 4 2 5± 5 9mm。 2 6例均无血栓栓塞并发症及出血并发症 ;1 9例术后即刻行同步电复律者 1 5例 ( 78 9% )复律成功。  相似文献   
70.
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