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   12597篇
  免费   939篇
  国内免费   301篇
耳鼻咽喉   92篇
儿科学   267篇
妇产科学   34篇
基础医学   682篇
口腔科学   19篇
临床医学   1612篇
内科学   5871篇
皮肤病学   6篇
神经病学   95篇
特种医学   344篇
外科学   2662篇
综合类   1353篇
现状与发展   1篇
预防医学   209篇
眼科学   205篇
药学   337篇
  3篇
中国医学   29篇
肿瘤学   16篇
  2024年   25篇
  2023年   339篇
  2022年   570篇
  2021年   886篇
  2020年   825篇
  2019年   830篇
  2018年   750篇
  2017年   414篇
  2016年   339篇
  2015年   473篇
  2014年   849篇
  2013年   729篇
  2012年   479篇
  2011年   613篇
  2010年   459篇
  2009年   490篇
  2008年   438篇
  2007年   435篇
  2006年   453篇
  2005年   403篇
  2004年   315篇
  2003年   305篇
  2002年   260篇
  2001年   241篇
  2000年   210篇
  1999年   205篇
  1998年   158篇
  1997年   148篇
  1996年   137篇
  1995年   128篇
  1994年   124篇
  1993年   102篇
  1992年   86篇
  1991年   73篇
  1990年   67篇
  1989年   58篇
  1988年   43篇
  1987年   62篇
  1986年   49篇
  1985年   56篇
  1984年   53篇
  1983年   29篇
  1982年   32篇
  1981年   20篇
  1980年   21篇
  1979年   16篇
  1978年   12篇
  1976年   10篇
  1974年   3篇
  1973年   7篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
41.
目的 探讨冠心病患者发生二尖瓣脱垂样改变的超声心动图特点,并分析其对治疗策略的影响.方法 选取北部战区总医院收治的同时行冠状动脉旁路移植与二尖瓣手术的171例患者为研究对象.根据冠状动脉病变严重程度将其分为A组(病变支数≥3支,n=98)与B组(病变支数1~2支,n=73).另选取我院同期收治的二尖瓣脱垂无冠心病行二尖...  相似文献   
42.
Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly, which is associated with other congenital heart diseases. It is diagnosed in neonates or childhood and rarely in adulthood. Nevertheless, AMVT is an incidental finding or described as isolated. Echocardiography, especially three-dimensional echocardiography is considered as an optimal imaging technique for AMVT diagnosis. We herein presented an asymptomatic adult AMVT cases with significant left ventricular outflow tract obstruction and surgical excision was recommended.  相似文献   
43.
目的:探讨四瓣技术在改良结膜囊泪囊鼻腔吻合术中应用的安全性及有效性。方法:回顾性临床研究。选取2017-09/2020-06在我院就诊的泪道疾病患者28例28眼作为研究对象,均行结膜囊泪囊鼻腔吻合术。术后随访6~12mo,观察患者手术效果、满意度及术后并发症情况。结果:本组患者术后荧光素钠染料排泄试验阳性率为96%(27/28),手术成功率为96%(27/28),其中治愈率为68%(19/28),好转率为28%(8/28),无效率为4%(1/28),患者总体满意度为93%(26/28)。术后并发症包括眼部异物感(28眼)、球结膜充血(11眼)、鼻腔结膜囊渗血(8眼)及泪道引流管脱出(1眼)。结论:四瓣技术用于改良结膜囊泪囊鼻腔吻合术手术成功率高,并发症少,安全有效。  相似文献   
44.
We report a case of a 44-year-old man with a clinical history of Tetralogy of Fallot status post staged surgical correction with mechanical pulmonic valve replacement who presented with progressive exertional dyspnea in the setting of non-compliance with anticoagulation. In the context of this suggestive clinical presentation, the diagnosis of mechanical pulmonic valve thrombosis (MPVT) was made possible via multimodality imaging, including transthoracic echocardiogram and cardiac computed tomography angiography. Due to the uncommon nature of the condition, the patient was treated with systemic thrombolysis and anticoagulation using evidence-based guidelines, largely extrapolated from left-sided mechanical valve thrombosis. Our case underscores the importance of anticoagulation in MPVT and recognizing the features of MPVT on clinical history, physical examination, and multimodality imaging. It is essential to understand the pivotal role of multimodality imaging in the assessment of MPVT and realize the limitations of available data regarding the management of MPVT in the current era.  相似文献   
45.
Pulmonary atresia with intact ventricular septum (PAIVS) is a rare congenital cardiac anomaly that has been classified into two types: one is a more frequent type having dysplasia of tricuspid valve (TV) with a small annulus, underdeveloped right ventricle (RV) with a hypoplastic cavity and a hypertrophic wall; the other type has severe dysplasia of TV and dilatation of RV, right atrium (RA), and right atrioventricular junction with thinning of the RV wall. We performed a morphologic study on 11 autopsied hearts with PAIVS, giving particular emphasis to the variation of morphology of the TV. We could classify these hearts into 3 groups according to the degree of right ventricular development. In the first group of 7 cases (type I), the RVs were underdeveloped. Thick leaflets, restricted valve apparatus with short chordae, and small annuli were characteristics of the TV. In the second group of 3 cases (type II), the RVs showed marked enlargement of the cavity and thinning of the wall. The TV showed redundant, dysplastic, sail-like anterior leaflets, and the downward displacement of septal leaflet and/or posterior leaflet, which are the findings frequently observed in Ebstein's malformation. The RVs were dilated and with partially unguarded tricuspid orifice. The septal leaflet of the TV was dysplastic and, in two cases, the septal leaflet showed chordal structure at the upper surface facing the RA, which is a peculiar finding that has not been described in the literature. The remaining case was a heart with a moderately developed RV (type III). The TV showed mildly dysplastic appearance and we classify this as a separate type, because we could expect the best surgical results in this type. This type had optimal size of RV and the mildest degree of dysplasia of TV. In PAIVS, the morphology of TV correlates well with the type of the right ventricular development.  相似文献   
46.
Forty-nine patients were studied to assess the value of M-modeand cross-sectional echocardiography in the diagnosis of mitralvalve prolapse. There were 20 normal subjects and 29 patientswith clinical and phonocardiographic evidence which suggestedprolapse. Using an arbitrary line connecting the base of theanterior and posterior leaflets at their attachment to the atrioventricularjunction, 22 of the 29 patients had abnormal arching of themitral leaflets into the left atrium on cross-sectional echocardiograms(CSE); this was not seen in the normal subjects. There were15 patients with double leaflet prolapse, five with lone anteriorand two with lone posterior leaflet prolapse. M-mode recordingsfailed to show prolapse in six of the 22 patients with positiveCSE but showed prolapse in one patient with an inadequate cross-sectionalechocardiogram. The difficulty in demonstrating prolapse onM-mode was caused by multiple systolic echoes in four subjects,and poor separation of the posterior leaflet from the posteriorleft ventricular wall echoes in two subjects. The anterior leafletwas well seen on CSE with long axis parasternal views but theposterior leaflet could not be seen on the long axis view in13 of the 29 subjects in the abnormal group; short axis fourchamber views from the apex allowed definition of the posteriorleaflet in nine of these 13 patients. We conclude that CSE is better than M-mode echocardiographyand should be used in conjunction with it for the diagnosisof mitral valve prolapse. Superior arching of the mitral leafletsinto the left atrium is the characteristic feature, and longaxis parasternal views should be supplemented by short axisfour chamber apical views.  相似文献   
47.
目的 探讨经股动脉主动脉瓣置换手术(TF-TAVR)和经心尖主动脉瓣置换手术(TA-TAVR)患者的CT影像学表现及差异。方法 选取我院经导管主动脉瓣置换手术(TAVR)共198例患者的临床资料,依据手术方式分成TFTAVR组100例和TA-TAVR组98例,术后经CT检查评定有无并发症发生,对比TF-TAVR组、TA-TAVR组患者的CT影像学参数和术后并发症出现情况。结果 两组(左冠状动脉,LM)至主动脉瓣环距离、窦直径、窦管交界直径、左心房大小及升主动脉钙化比例相比差异无统计学意义(P> 0.05),TF-TAVR组的右冠状动脉(RCA)至主动脉瓣环距离及左心室大小均大于TA-TAVR组(P<0.05)。TF-TAVR组的瓣周漏出现比例为63.00%高于TA-TAVR组42.86%(P<0.05);TF-TAVR组的心包积液出现比例为18.00%高于TA-TAVR组7.14%(P<0.05);TF-TAVR组的肺膨胀不全出现比例为3.00%低于TA-TAVR组11.22%(P<0.05);TF-TAVR组的胸腔积液出现比例为43.00%和TA-TAV...  相似文献   
48.
49.
50.
目的探索主动脉瓣膜重度狭窄行经导管主动脉瓣膜置入治疗患者的围手术期管理.方法选择1例主动脉瓣膜重度狭窄行经导管主动脉瓣膜置入治疗的患者,组成多学科协作手术团队,术前充分评估,术中严密监测,术后安全监护(CCU)及康复,定期随访.结果本例手术成功,无处置及护理不当并发症;随访12个月,患者活动后胸闷症状明显缓解,活动耐力逐步提升,生存质量提高.结论利用团队优势,做好围手术期管理,可以顺利完成手术,促进患者康复.  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