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   2481715篇
  免费   372758篇
  国内免费   37503篇
耳鼻咽喉   33879篇
儿科学   80744篇
妇产科学   65185篇
基础医学   388434篇
口腔科学   65170篇
临床医学   251736篇
内科学   510174篇
皮肤病学   52901篇
神经病学   198167篇
特种医学   96089篇
外国民族医学   898篇
外科学   368661篇
综合类   96187篇
现状与发展   4篇
一般理论   894篇
预防医学   213277篇
眼科学   67684篇
药学   218622篇
  10篇
中国医学   50531篇
肿瘤学   132729篇
  2019年   30411篇
  2018年   37604篇
  2017年   32505篇
  2016年   32809篇
  2015年   35555篇
  2014年   44010篇
  2013年   60778篇
  2012年   78270篇
  2011年   84106篇
  2010年   57153篇
  2009年   61052篇
  2008年   78116篇
  2007年   79790篇
  2006年   79081篇
  2005年   77352篇
  2004年   77176篇
  2003年   73814篇
  2002年   72124篇
  2001年   114020篇
  2000年   113582篇
  1999年   100668篇
  1998年   34112篇
  1997年   30819篇
  1996年   31420篇
  1995年   31713篇
  1994年   30229篇
  1993年   27964篇
  1992年   81024篇
  1991年   79536篇
  1990年   76630篇
  1989年   74024篇
  1988年   68653篇
  1987年   67280篇
  1986年   63422篇
  1985年   60168篇
  1984年   45620篇
  1983年   39512篇
  1982年   25648篇
  1981年   23498篇
  1979年   42513篇
  1978年   31183篇
  1977年   26980篇
  1976年   25205篇
  1975年   26701篇
  1974年   31298篇
  1973年   30441篇
  1972年   28659篇
  1971年   26297篇
  1970年   24755篇
  1969年   22903篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
2.

Background

Glutamate plays a key role for post-ischaemic recovery of myocardial metabolism. According to post hoc analyses of the two GLUTAMICS trials, patients without diabetes benefit from glutamate with less myocardial dysfunction after coronary artery bypass surgery (CABG). Copeptin reflects activation of the Arginine Vasopressin system and is a reliable marker of heart failure but available studies in cardiac surgery are limited. We investigated whether glutamate infusion is associated with reduced postoperative rises of plasma Copeptin (p-Copeptin) after CABG.

Methods

A prespecified randomised double-blind substudy of GLUTAMICS II. Patients had left ventricular ejection fraction ≤0.30 or EuroSCORE II ≥3.0 and underwent CABG ± valve procedure. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h was commenced 10–20 min before the release of the aortic cross-clamp and then continued for another 150 min P-Copeptin was measured preoperatively and postoperatively on day one (POD1) and day three. The primary endpoint was an increase in p-Copeptin from the preoperative level to POD1. Postoperative stroke ≤24 h and mortality ≤30 days were safety outcomes.

Results

We included 181 patients of whom 48% had diabetes. The incidence of postoperative mortality ≤30 days (0% vs. 2.1%; p = .50) and stroke ≤24 h (0% vs. 3.2%; p = .25) did not differ between the glutamate group and controls. P-Copeptin increased postoperatively with the highest values recorded on POD1 without significant inter-group differences. Among patients without diabetes, p-Copeptin did not differ preoperatively but postoperative rise from preoperative level to POD1 was significantly reduced in the glutamate group (73 ± 66 vs. 115 ± 102 pmol/L; p = .02). P-Copeptin was significantly lower in the Glutamate group on POD1 (p = .02) and POD 3 (p = .02).

Conclusions

Glutamate did not reduce rises of p-Copeptin significantly after moderate to high-risk CABG. However, glutamate was associated with reduced rises of p-Copeptin among patients without diabetes. These results agree with previous observations suggesting that glutamate mitigates myocardial dysfunction after CABG in patients without diabetes. Given the exploratory nature of these findings, they need to be confirmed in future studies.  相似文献   
3.
Modified-release opioids are often prescribed for the management of moderate to severe acute pain following total hip and knee arthroplasty, despite recommendations against their use due to increasing concerns regarding harm. The primary objective of this multicentre study was to examine the impact of modified-release opioid use on the incidence of opioid-related adverse events compared with immediate-release opioid use, among adult inpatients following total hip or knee arthroplasty. Data for total hip and knee arthroplasty inpatients receiving an opioid analgesic for postoperative analgesia during hospitalisation were collected from electronic medical records of three tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events during hospital admission. Patients who received modified with or without immediate-release opioids were matched to those receiving immediate-release opioids only (1:1) using nearest neighbour propensity score matching with patient and clinical characteristics as covariates. This included total opioid dose received. In the matched cohorts, patients given modified-release opioids (n = 347) experienced a higher incidence of opioid-related adverse events overall, compared with those given immediate-release opioids only (20.5%, 71/347 vs. 12.7%, 44/347; difference in proportions 7.8% [95%CI 2.3–13.3%]). Modified-release opioid use was associated with an increased risk of harm when used for acute pain during hospitalisation after total hip or knee arthroplasty.  相似文献   
4.
5.
Neuroscience and Behavioral Physiology - We present here results from analysis of the formation of brain bioelectrical activity in children and adolescents living in the northern region of Russia...  相似文献   
6.
经皮椎体成形术是一种安全有效的微创手术,腹膜后血肿是其罕见但严重的并发症。我们报告一例经皮椎体成形术RH阴性(熊猫血)患者术后并发巨大腹膜后血肿,经保守和输血等支持治疗,病人康复出院。脊柱医生应了解这种罕见但潜在致命的并发症,因为早期认识和及时预防是降低其发病率的基础。  相似文献   
7.
Mixed lineage leukemia 1(MLL1)是组蛋白甲基转移酶SET家族的成员之一。MLL1与WDR5、RbBP5、Ash2L和DPY-30组成MLL1甲基转移酶复合物调控组蛋白H3的第4位赖氨酸的甲基化水平,对造血系统的发育和血细胞的更新至关重要。部分白血病患者体内存在因MLL1基因易位而产生的致癌蛋白——MLL1融合蛋白,MLL1融合蛋白在发挥其致癌作用时需要功能完整的MLL1酶复合物,故靶向MLL1-WDR5的蛋白-蛋白相互作用成为治疗MLL1融合型白血病的潜在策略。本文对MLL1-WDR5蛋白-蛋白相互作用的生物学机制、结构信息以及抑制剂进行了系统的总结,并结合已报道数据对该领域进行了展望,以期为后续研究提供参考。  相似文献   
8.
9.
10.
In 2019, the scientists who discovered how cells sense and adapt to oxygen availability were awarded the Nobel Prize. This elegant sensing pathway is conserved throughout evolution, and it underpins the physiology and pathology that we, as clinicians in anaesthesia and critical care, encounter on a daily basis. The purpose of this review is to bring hypoxia-inducible factor, and the oxygen-sensing pathway as a whole, to the wider clinical community. We describe how this unifying mechanism was discovered, and how it orchestrates diverse changes such as erythropoiesis, ventilatory acclimatisation, pulmonary vascular remodelling and altered metabolism. We explore the lessons learnt from genetic disorders of oxygen sensing, and the wider implications in evolution of all animal species, including our own. Finally, we explain how this pathway is relevant to our clinical practice, and how it is being manipulated in new treatments for conditions such as cancer, anaemia and pulmonary hypertension.  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