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   772896篇
  免费   313656篇
  国内免费   67057篇
耳鼻咽喉   7372篇
儿科学   10227篇
妇产科学   11026篇
基础医学   151136篇
口腔科学   11689篇
临床医学   129541篇
内科学   173264篇
皮肤病学   10180篇
神经病学   48756篇
特种医学   27239篇
外国民族医学   288篇
外科学   96808篇
综合类   133479篇
现状与发展   109篇
一般理论   67篇
预防医学   74049篇
眼科学   29935篇
药学   108628篇
  468篇
中国医学   71151篇
肿瘤学   58197篇
  2023年   9423篇
  2022年   22404篇
  2021年   28007篇
  2020年   23935篇
  2019年   28622篇
  2018年   30182篇
  2017年   28852篇
  2016年   26653篇
  2015年   33961篇
  2014年   39204篇
  2013年   37329篇
  2012年   49282篇
  2011年   55104篇
  2010年   41775篇
  2009年   43883篇
  2008年   39248篇
  2007年   36980篇
  2006年   36324篇
  2005年   35855篇
  2004年   28921篇
  2003年   27084篇
  2002年   25104篇
  2001年   25303篇
  2000年   21074篇
  1999年   26585篇
  1998年   21989篇
  1997年   21792篇
  1996年   20863篇
  1995年   20529篇
  1994年   19443篇
  1993年   16452篇
  1992年   17322篇
  1991年   15931篇
  1990年   14428篇
  1989年   13812篇
  1988年   12844篇
  1987年   12078篇
  1986年   11196篇
  1985年   9970篇
  1984年   7433篇
  1983年   7218篇
  1982年   7988篇
  1981年   7450篇
  1980年   7080篇
  1979年   7031篇
  1978年   6009篇
  1977年   6286篇
  1976年   5888篇
  1975年   5602篇
  1974年   5231篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Abstract

Background: This study aims to compare the effectiveness of inhaled prostacyclin or its analoguesversus nitric oxide (NO) in treating pulmonary hypertension (PH) after cardiac or pulmonary surgery remains unclear.

Methods: PubMed, Cochrane, and Embase databases were searched for literature published prior to December 2019 using the following keywords: inhaled, nitric oxide, prostacyclin, iloprost, treprostinil, epoprostenol, Tyvaso, flolan, and pulmonary hypertension. Randomized controlled trials and multiple-armed prospective studies that evaluated inhaled NO versus prostacyclin (or analogues) in patients for perioperative and/or postoperative PH after either cardiac or pulmonary surgery were included. Retrospective studies, reviews, letters, comments, editorials, and case reports were excluded.

Results: Seven studies with a total of 195 patients were included. No difference in the improvement of mean pulmonary arterial pressure (pooled difference in mean change= ?0.10, 95% CI: ?3.98 to 3.78, p?=?.959) or pulmonary vascular resistance (pooled standardized difference in mean change= ?0.27, 95% CI: ?0.60 to 0.05, p?=?.099) were found between the two treatments. Similarly, no difference was found in other outcomes between the two treatments or subgroup analysis.

Conclusions: Inhaled prostacyclin (or analogues) was comparable to inhaled NO in treating PH after cardiac or pulmonary surgery.
  • Key messages
  • This study compared the efficacy of inhaled prostacyclin or its analogues versus inhaled NO to treat PH after surgery. The two types of agent exhibited similar efficacy in managing MPAP, PVR, heart rate, and cardiac output was observed.

  • Inhaled prostacyclin may serve as an alternative treatment option for PH after cardiac or pulmonary surgery.

  相似文献   
12.
13.
Laparoscopic surgery has several advantages over traditional surgery because it has been shown to be less invasive. The next logical step in the evolution of minimally invasive surgery may be to eliminate all abdominal incisions. The natural orifices provide a port of entry via the gastrointestinal tract to the peritoneal cavity. This approach would require the creation of a perforation, which is considered to be a major complication of endoscopy with significant morbidity and mortality. However, there are several recent studies that have described the technical feasibility and safety of a per‐oral transgastric approach to the peritoneal cavity using conventional endoscopes. Theoretically, this approach could reduce postoperative abdominal wall pain, wound infection, hernia formation, and adhesions. This article aims to summarize the current status of transgastric surgery, currently referred to as natural orifice transluminal endoscopic surgery (NOTES), and to address some of its future challenges.  相似文献   
14.
15.
16.
Coronary magnetic resonance angiography (CMRA) is a technique in clinical evolution. Current clinical applications include assessment for coronary anomalies, aneurysms, bypass graft patency, and, in experienced centers, the exclusion of proximal and multivessel coronary artery disease (CAD). As local expertise increases and more extensive multicenter data become available, additional applications will be established. CMRA promises to supplement and in some cases obviate the need for X-ray contrast angiography, and to expand our understanding of the pathophysiology of CAD. Zusammenfassung Die Magnetresonanzangiographie der Koronargefäße (CMRA) ist eine sich ständig weiterentwickelnde Technik. Etablierte Anwendungen sind zurzeit die Beurteilung von koronaren Anomalien, Aneurysmen und der Durchgängigkeit von Bypasses. Auch der Ausschluss proximaler Koronarstenosen und einer koronaren Mehrgefäßerkrankung ist in einigen spezialisierten Zentren möglich. Mit zunehmender Erfahrung der jeweiligen Anwender und der Verfügbarkeit von Ergebnissen großer multizentrischer Studien können zukünftig weitere klinische Anwendungen etabliert werden. In der Zukunft könnte die CMRA ergänzende Informationen zur Indikationsstellung einer konventionellen Röntgenangiographie bringen und in einigen Fällen diese Untersuchung sogar ersetzen. Die CMRA wird unseren Einblick in die Pathophysiologie der koronaren Herzerkrankung sicher erweitern.  相似文献   
17.
BACKGROUND/PURPOSE: Sensitive skin is a condition associated with reduced tolerance to environmental factors and/or the application of topical products, such as cosmetics. Its pathophysiology has not been fully elucidated and few data are available on its prevalence. The aim of this study was to investigate possible correlation between objective sensitivity and skin surface microrelief. METHODS: During an epidemiological survey conducted for a campaign promoted by International Society of Plastic Dermatology in Italy, 243 adult healthy subjects of both sexes with no evident dermatological disorder but positive to the lactic acid stinging test, were submitted to cyanoacrylate stratum corneum stripping from the volar forearm for the determination of the irregularity of the skin surface microrelief (irregularity skin index (ISI)). RESULTS: A significant correlation was found between intensity of symptoms in stingers and ISI (r(s)=-0.47; P<0.001). CONCLUSION: Sensitive skin is common in the healthy population. ISI can contribute towards the identification of subjects with sensitive skin and the development of more specific skin treatments for this prevalent condition.  相似文献   
18.
19.
20.
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