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   18229篇
  免费   1297篇
  国内免费   448篇
耳鼻咽喉   15篇
儿科学   384篇
妇产科学   58篇
基础医学   853篇
口腔科学   15篇
临床医学   2061篇
内科学   5929篇
皮肤病学   11篇
神经病学   1688篇
特种医学   1479篇
外科学   4508篇
综合类   1909篇
现状与发展   1篇
预防医学   218篇
眼科学   62篇
药学   567篇
  4篇
中国医学   108篇
肿瘤学   104篇
  2024年   26篇
  2023年   407篇
  2022年   709篇
  2021年   1141篇
  2020年   1037篇
  2019年   1000篇
  2018年   853篇
  2017年   633篇
  2016年   544篇
  2015年   734篇
  2014年   1154篇
  2013年   1215篇
  2012年   794篇
  2011年   956篇
  2010年   751篇
  2009年   770篇
  2008年   801篇
  2007年   711篇
  2006年   689篇
  2005年   612篇
  2004年   523篇
  2003年   446篇
  2002年   409篇
  2001年   342篇
  2000年   239篇
  1999年   220篇
  1998年   227篇
  1997年   205篇
  1996年   206篇
  1995年   157篇
  1994年   155篇
  1993年   155篇
  1992年   138篇
  1991年   127篇
  1990年   109篇
  1989年   86篇
  1988年   73篇
  1987年   79篇
  1986年   73篇
  1985年   77篇
  1984年   86篇
  1983年   52篇
  1982年   61篇
  1981年   57篇
  1980年   33篇
  1979年   30篇
  1978年   22篇
  1977年   13篇
  1976年   14篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
Heritable thoracic aortic diseases (HTAD) are rare pathologies associated with thoracic aortic aneurysms and dissection, which can be syndromic or non-syndromic. They may result from genetic defects. Associated genes identified to date are classified into those encoding components of the (a) extracellular matrix (b) TGFβ pathway and (c) smooth muscle contractile mechanism. Timely diagnosis allows for prompt aortic surveillance and prophylactic surgery, hence improving life expectancy and reducing maternal complications as well as providing reassurance to family members when a diagnosis is ruled out. This document is an expert opinion reflecting strategies put forward by medical experts and patient representatives involved in the HTAD Rare Disease Working Group of VASCERN. It aims to provide a patient pathway that improves patient care by diminishing time to diagnosis, facilitating the establishment of a correct diagnosis using molecular genetics when possible, excluding the diagnosis in unaffected persons through appropriate family screening and avoiding overuse of resources. It is being recommended that patients are referred to an expert centre for further evaluation if they meet at least one of the following criteria: (1) thoracic aortic dissection (<70 years if hypertensive; all ages if non-hypertensive), (2) thoracic aortic aneurysm (all adults with Z score >3.5 or 2.5–3.5 if non-hypertensive or hypertensive and <60 years; all children with Z score >3), (3) family history of HTAD with/without a pathogenic variant in a gene linked to HTAD, (4) ectopia lentis without other obvious explanation and (5) a systemic score of >5 in adults and >3 in children. Aortic imaging primarily relies on transthoracic echocardiography with magnetic resonance imaging or computed tomography as needed. Genetic testing should be considered in those with a high suspicion of underlying genetic aortopathy. Though panels vary among centers, for patients with thoracic aortic aneurysm or dissection or systemic features these should include genes with a definitive or strong association to HTAD. Genetic cascade screening and serial aortic imaging should be considered for family screening and follow-up. In conclusion, the implementation of these strategies should help standardise the diagnostic work-up and follow-up of patients with suspected HTAD and the screening of their relatives.  相似文献   
162.
163.
164.
165.
166.
167.
Objective: Our study aimed to evaluate short- and long-term outcomes of patients who required emergent conversion from transcatheter aortic valve implantation (TAVI) to open surgery. Besides, the reasons and procedural settings of emergent cardiac surgery (ECS) were also reported.Methods: We retrospectively reviewed the patients who underwent TAVI in our institution between 2012 and 2019 and collected the clinical data of cases who converted from TAVI to bail-out surgery. Telephone and outpatient follow-ups were performed.Results: Of 516 TAVI patients, 20 required ECS, and the bail-out surgery occurred less frequently with the increase in TAVI volume. The most common reason for conversion was left ventricular perforation (7/20, 35.0%). Thirty-day mortality was 35.0% in ECS patients. Kaplan–Meier survival curves showed that the cumulative survival rate was 65.0% at 1 year, 50.1% at 5 years in all ECS patients, and 77.1% at 5 years in patients who survived over 30 days after conversion.Conclusion: Although the bail-out operation was performed immediately after TAVI abortion, ECS still associated with high 30-day mortality. The long-term survival benefit was seen in patients surviving from bail-out surgery. An experienced TAVI team is of crucial importance in avoiding ECS-related life-threatening complications and providing effective salvage surgery.  相似文献   
168.
目的探讨高分辨率MR(HRMR)血管壁成像(VWI)所测壁强化指数(WEI)评估颅内动脉瘤不稳定性的价值。方法回顾性分析174例未破裂颅内动脉瘤患者。以3D-DSA观察动脉瘤大小、位置、形态。基于HRMR血管壁成像主观评估是否有动脉瘤壁强化(AWE),并采用软件计算WEI。采用ELAPSS及PHASES评分评估动脉瘤生长风险及破裂风险。以Spearman相关分析观察WEI与动脉瘤生长及破裂风险的相关性。结果 174例患者共248个无症状未破裂颅内囊状动脉瘤,HRMR VWI示AWE 78个、无AWE 170个。AWE与无AWE动脉瘤大小、位置、形态、ELAPSS评分、生长风险、PHASES评分、5年破裂风险差异均有统计学意义(P均0.05)。AWE动脉瘤WEI高于无AWE动脉瘤(P0.001)。Spearman相关分析显示,WEI与动脉瘤3年、5年生长风险(r_s=0.40、0.40,P均0.01)及5年破裂风险(r_s=0.24,P0.01)均呈正相关。结论 HRMR VWI所测WEI越高,提示动脉瘤不稳定性越高。  相似文献   
169.
目的观察介入治疗内脏动脉瘤(VAA)的远期疗效。方法回顾性分析30例接受介入治疗VAA患者(41个瘤灶),术后随访时间均12个月,观察治疗效果及并发症。结果对12个肾动脉瘤、8个脾动脉瘤行动脉瘤填塞术,其中5个脾动脉瘤、5个肾动脉瘤采用裸支架辅助填塞;对13个脾动脉瘤、1个肝动脉瘤行动脉瘤栓塞术;对4个肾动脉瘤行载瘤动脉支架植入术,其中3个采用多层裸支架植入术、1个采用覆膜支架植入术;对2个肾动脉瘤、1个腹腔干动脉瘤行保守治疗;均获得成功。1个脾动脉瘤栓塞术后出现部分脾梗死,1个左肾多发动脉瘤植入支架后瘤腔小部分显影。术后随访12~55个月,平均(23.44±12.48)个月,期间脾梗死者梗死面积未增大、未见脓肿形成,瘤腔部分显影病变显影面积未增大。30例患者中,1例因心力衰竭死亡,余均存活,无VAA复发及其他并发症。结论介入治疗VAA远期疗效较好,且安全性较高。  相似文献   
170.
IntroductionAneurysm of splenic artery arising from splenomesentric trunk is an extremely rare condition. The aim of this study is to report a new case with literature review.Presentation of caseA 52-year-old housewife presented with mild central abdominal pain for two month duration. Abdomen was soft. Abdominal ultrasound examination showed a focal aneurysmal dilatation in the splenic artery (SA) near the portal vein. Abdominal computed tomographic angiography (CTA) revealed presence of the splenomesentric trunk with fusiform aneurysm (45 × 33 mm) of the proximal part of the SA. In supine position, through upper midline laparotomy incision, exploration of both superior mesenteric artery (SMA) and SA was performed, total excision of the aneurysm was done, the SMA was side-repaired and SA was ligated. The post-operative period was uneventful.DiscussionIt is interesting to note that orthotopic SA aneurysms, most commonly present in the distal third of the artery, followed by the middle third, while in cases of splenomesentric trunk, all reported cases of anomalous SA aneurysms including the current one, showed the aneurysms to be located in the proximal portion or root of the SA.ConclusionSplenomesentric trunk is a rare anatomical anomaly, aneurysm of which is even rarer. It can be managed either by endovascular intervention or open surgery.  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