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   2340093篇
  免费   175778篇
  国内免费   3291篇
耳鼻咽喉   32115篇
儿科学   75990篇
妇产科学   62868篇
基础医学   346497篇
口腔科学   63936篇
临床医学   210999篇
内科学   454258篇
皮肤病学   51807篇
神经病学   184680篇
特种医学   88219篇
外国民族医学   492篇
外科学   353815篇
综合类   47542篇
现状与发展   12篇
一般理论   857篇
预防医学   182254篇
眼科学   54357篇
药学   175244篇
  9篇
中国医学   4409篇
肿瘤学   128802篇
  2019年   19672篇
  2018年   27207篇
  2017年   20470篇
  2016年   22878篇
  2015年   25774篇
  2014年   36311篇
  2013年   54260篇
  2012年   75124篇
  2011年   79877篇
  2010年   47313篇
  2009年   44776篇
  2008年   75071篇
  2007年   79918篇
  2006年   80727篇
  2005年   78237篇
  2004年   74815篇
  2003年   72003篇
  2002年   69564篇
  2001年   108823篇
  2000年   111413篇
  1999年   93109篇
  1998年   25483篇
  1997年   22053篇
  1996年   22448篇
  1995年   22681篇
  1994年   20862篇
  1993年   19703篇
  1992年   72105篇
  1991年   70247篇
  1990年   68577篇
  1989年   65849篇
  1988年   60450篇
  1987年   59264篇
  1986年   55358篇
  1985年   53119篇
  1984年   39357篇
  1983年   33431篇
  1982年   19845篇
  1981年   17849篇
  1979年   35907篇
  1978年   25673篇
  1977年   21227篇
  1976年   20369篇
  1975年   21838篇
  1974年   26193篇
  1973年   24880篇
  1972年   23284篇
  1971年   22093篇
  1970年   20312篇
  1969年   19349篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
1.
2.
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   
3.
In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies.  相似文献   
4.
5.
6.
The Extracellular Vesicle Flow Cytometry Working Group ( http://www.evflowcytometry.org ) is formed by members of the International Society for Extracellular Vesicles (ISEV), the International Society for Advancement of Cytometry (ISAC), and the International Society on Thrombosis and Haemostasis (ISTH). This working group of flow cytometry experts develops guidelines for best practices regarding flow cytometry detection of extracellular vesicles. To improve rigor and standardization, this working group published a framework outlining the minimal information to report about a flow cytometry experiment on extracellular vesicles (MIFlowCyt-EV) in the Journal of Extracellular Vesicles, the ISEV journal, in 2020. In parallel, an article explaining MIFlowCyt-EV was published in Cytometry Part A, one of the ISAC journals, and now will be introduced to the ISTH as an SSC Communication in the Journal of Thrombosis and Haemostasis. The goal of this SSC Communication is to explain why flow cytometry is becoming the instrument of choice to characterize single extracellular vesicles, the obstacles that have been identified and (mostly) overcome by developing procedures to calibrate flow cytometers, and the relevance of reporting minimal information to improve reliability and reproducibility of experiments in which flow cytometers are used for characterization of extracellular vesicles.  相似文献   
7.
Troppmair  Teresa  Egger  J.  Krösbacher  A.  Zanvettor  A.  Schinnerl  A.  Neumayr  A.  Baubin  M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall...  相似文献   
8.
9.
10.
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