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   2357729篇
  免费   177153篇
  国内免费   3348篇
耳鼻咽喉   32231篇
儿科学   76341篇
妇产科学   63302篇
基础医学   348940篇
口腔科学   63950篇
临床医学   213082篇
内科学   457512篇
皮肤病学   52017篇
神经病学   186156篇
特种医学   88696篇
外国民族医学   492篇
外科学   356764篇
综合类   47897篇
现状与发展   12篇
一般理论   895篇
预防医学   183950篇
眼科学   54900篇
药学   176747篇
  10篇
中国医学   4442篇
肿瘤学   129894篇
  2019年   20103篇
  2018年   27643篇
  2017年   20805篇
  2016年   23293篇
  2015年   26257篇
  2014年   36946篇
  2013年   55292篇
  2012年   76499篇
  2011年   81337篇
  2010年   48171篇
  2009年   45575篇
  2008年   76242篇
  2007年   81207篇
  2006年   82040篇
  2005年   79566篇
  2004年   76154篇
  2003年   73120篇
  2002年   70614篇
  2001年   108936篇
  2000年   111506篇
  1999年   93264篇
  1998年   25683篇
  1997年   22216篇
  1996年   22609篇
  1995年   22820篇
  1994年   20977篇
  1993年   19820篇
  1992年   72121篇
  1991年   70298篇
  1990年   68552篇
  1989年   65830篇
  1988年   60435篇
  1987年   59256篇
  1986年   55358篇
  1985年   53135篇
  1984年   39383篇
  1983年   33472篇
  1982年   19912篇
  1981年   17922篇
  1979年   35901篇
  1978年   25661篇
  1977年   21237篇
  1976年   20337篇
  1975年   21831篇
  1974年   26190篇
  1973年   24842篇
  1972年   23261篇
  1971年   22091篇
  1970年   20272篇
  1969年   19349篇
排序方式: 共有10000条查询结果,搜索用时 20 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.
8.
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   
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