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   1366133篇
  免费   94584篇
  国内免费   1984篇
耳鼻咽喉   18887篇
儿科学   45457篇
妇产科学   39204篇
基础医学   197738篇
口腔科学   35895篇
临床医学   113783篇
内科学   269823篇
皮肤病学   26928篇
神经病学   108267篇
特种医学   54015篇
外国民族医学   366篇
外科学   213307篇
综合类   27307篇
现状与发展   1篇
一般理论   300篇
预防医学   100957篇
眼科学   29948篇
药学   102496篇
  1篇
中国医学   2500篇
肿瘤学   75521篇
  2018年   22410篇
  2017年   17578篇
  2016年   20399篇
  2015年   11965篇
  2014年   16255篇
  2013年   24594篇
  2012年   36441篇
  2011年   45295篇
  2010年   28756篇
  2009年   25513篇
  2008年   44740篇
  2007年   49932篇
  2006年   38708篇
  2005年   39706篇
  2004年   38802篇
  2003年   38950篇
  2002年   37258篇
  2001年   58377篇
  2000年   60064篇
  1999年   50872篇
  1998年   14416篇
  1997年   13057篇
  1996年   13195篇
  1995年   12487篇
  1994年   11919篇
  1993年   10999篇
  1992年   41092篇
  1991年   40479篇
  1990年   40010篇
  1989年   38814篇
  1988年   36207篇
  1987年   35461篇
  1986年   33816篇
  1985年   32232篇
  1984年   23984篇
  1983年   20882篇
  1982年   12454篇
  1981年   10940篇
  1979年   22720篇
  1978年   15934篇
  1977年   13746篇
  1976年   13022篇
  1975年   14202篇
  1974年   16702篇
  1973年   16083篇
  1972年   15318篇
  1971年   14229篇
  1970年   13237篇
  1969年   12760篇
  1968年   11997篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
171.
BackgroundHepatopancreatobiliary (HPB) surgery fellowship training has multiple paths. Prospective trainees and employers must understand the differences between training pathways. This study examines self-reported fellowship experiences and current scope of practice across three pathways.MethodsAn online survey was disseminated to 654 surgeons. These included active Americas Hepato-Pancreato-Biliary Association (AHPBA) members and recent graduates of HPB, transplant–HPB and HPB–heavy surgical oncology fellowships.ResultsA total of 416 (64%) surgeons responded. Most respondents were male (89%) and most were practising in an academic setting (83%). 290 (70%) respondents underwent formal fellowship training. Although fellowship experiences varied, current practice was largely similar. Minimally invasive surgery (MIS) and ultrasound were the most commonly identified areas of training deficiencies and were, respectively, cited as such by 47% and 34% of HPB-, 49% and 50% of transplant-, and 52% and 25% of surgical oncology-trained respondents. Non-HPB cases performed in current practice included gastrointestinal (GI) and general surgery cases (56% and 49%, respectively) for HPB-trained respondents, transplant and general surgery cases (87% and 21%, respectively) for transplant-trained respondents, and GI surgery and non-HPB surgical oncology cases (70% and 28%, respectively) for surgical oncology-trained respondents.ConclusionsFellowship training in HPB surgery varies by training pathway. Training in MIS and ultrasound is deficient in each pathway. The ultimate scope of non-transplant HPB practice appears similar across training pathways. Thus, training pathway choice is best guided by the training experience desired and non-HPB components of anticipated practice.  相似文献   
172.
173.
174.
Respiratory failure is defined by the inability of the respiratory system to adequately deliver oxygen or remove carbon dioxide from the pulmonary circulation resulting in hypoxemia, hypercapnia or both. A wide variety of disease processes can lead to respiratory failure in children. Multiple interventions can support the paediatric patient with respiratory failure, from simple oxygen delivery devices to high frequency oscillatory ventilation and extracorporeal membrane oxygenation. This article will review available devices to improve oxygenation and ventilation, their advantages and disadvantages, and help guide physicians in the management of children with respiratory failure.  相似文献   
175.
176.
177.
To improve the diagnostic accuracy of electroencephalography (EEG) criteria for nonconvulsive status epilepticus (NCSE), external validation of the recently proposed Salzburg criteria is paramount. We performed an external, retrospective, diagnostic accuracy study of the Salzburg criteria, using EEG recordings from patients with and without a clinical suspicion of having NCSE. Of the 191 EEG recordings, 12 (12%) was classified as an NCSE according to the reference standard. In the validation cohort, sensitivity was 67% and specificity was 89%. The positive predictive value was 47% and the negative predictive value was 95%. Ten patients in the control group (n = 93) were false positive, resulting in a specificity of 89.2%. The interrater agreement between the reference standards and between the scorers of the Salzburg criteria was moderate; disagreement occurred mainly in patients with an epileptic encephalopathy. The Salzburg criteria showed a lower diagnostic accuracy in our external validation study than in the original design, suggesting that they cannot replace the current practice of careful weighing of both clinical and EEG information on an individual basis.  相似文献   
178.
ABSTRACT

Introduction

Immune checkpoint inhibitors (ICIs) have proved to be groundbreaking in the field of oncology. However, immune system overactivation from ICIs has introduced a novel medical entity known as immune-related adverse events (irAEs), that can affect any organ or tissue. ICI-induced inflammatory arthritis (ICI-IIA) is the most common musculoskeletal irAE and can lead to significant morbidity and limitation in anti-cancer therapy.  相似文献   
179.
Neurological Sciences - Chronic subdural haematoma (CSDH) is one of the most common neurosurgical pathologies. The recurrence of chronic subdural haematomas is an important concern, considering...  相似文献   
180.
Abstract

This study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, n?=?39) and normally conceived (control group, n?=?68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro- anti-angiogenic factors balance and increase in vascular impedance in ART-conceived embryos.  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