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   6873篇
  免费   427篇
  国内免费   1篇
  2023年   22篇
  2022年   66篇
  2021年   103篇
  2020年   84篇
  2019年   92篇
  2018年   139篇
  2017年   106篇
  2016年   190篇
  2015年   282篇
  2014年   372篇
  2013年   519篇
  2012年   579篇
  2011年   528篇
  2010年   354篇
  2009年   292篇
  2008年   443篇
  2007年   380篇
  2006年   383篇
  2005年   333篇
  2004年   358篇
  2003年   348篇
  2002年   327篇
  2001年   79篇
  2000年   73篇
  1999年   69篇
  1998年   68篇
  1997年   59篇
  1996年   60篇
  1995年   49篇
  1994年   62篇
  1993年   44篇
  1992年   45篇
  1991年   33篇
  1990年   27篇
  1989年   24篇
  1988年   21篇
  1987年   19篇
  1986年   13篇
  1985年   21篇
  1984年   21篇
  1983年   23篇
  1982年   18篇
  1981年   28篇
  1980年   24篇
  1979年   18篇
  1978年   10篇
  1977年   18篇
  1975年   8篇
  1974年   13篇
  1973年   9篇
排序方式: 共有7301条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The aim of this study was to identify plant species among the diverse flora of the caatinga ecosystem that are used therapeutically. Research was undertaken in the municipalities of Piranhas and Delmiro Gouveia, in the Xingó region (state of Alagoas, NE Brazil). In order to identify the medicinal plants used in this region, semi-structured questionnaires were applied. The species cited were collected and sent to the Xingó Herbarium for taxonomic analysis. The relative importance (RI) of each species cited was calculated to verify their cultural importance. The therapeutic indications attributed to the species were classified under 16 body systems. A total of 187 medicinal species were cited, from 64 families and 128 genera. The main indications for medicinal plant use were against common colds, bronchitis, cardiovascular problems, kidney problems, inflammations in general, and as tranquilizers. Approximately 16% (30 plant species) were versatile in relation to their use, with an Relative Importance value over 1, having been indicated for up to nine body systems. The body systems that stood out the most were: the respiratory system, the gastrointestinal system, and infectious diseases. Most cited plant parts used for medicinal purposes were flowers, leaves, and inner stem bark.  相似文献   
5.
Zofenopril is a pro-drug designed to undergo metabolic hydrolysis yielding the active free sulfhydryl compound zofenoprilat, which is an angiotensin converting enzyme (ACE) inhibitor, endowed also with a marked cardioprotective activity. A simple, highly sensitive specific LC–MS–MS method was developed for the determination of zofenopril and zofenoprilat in human plasma. In order to prevent oxidative degradation of zofenoprilat and its internal standard, their free sulfhydryl groups were protected by treatment with N-ethylmaleimide (NEM), which produced the succinimide derivatives. The compounds and their corresponding fluorine derivatives, used as internal standards, were extracted from plasma with toluene. The reconstituted dried extracts were chromatographed and then monitored by a triple-stage-quadrupole instrument operating in the negative ion spray ionization mode. The method was validated over the concentration range of 1–300 ng/ml for zofenopril and 2–600 ng/ml for zofenoprilat. Inter- and intra-assay precision and accuracy of both zofenopril and zofenoprilat were better than 10%. The limit of quantitation was 1 ng/ml with zofenopril and 2 ng/ml with zofenoprilat. Extraction recovery proved to be on average 84.8% with zofenopril and 70.1% with zofenoprilat. Similar recoveries were shown by the above two internal standards. The method was applied to measure plasma concentrations of zofenopril and zofenoprilat in 18 healthy volunteers treated orally with zofenopril calcium salt at the dose of 60 mg.  相似文献   
6.
7.
8.
9.
Alzheimer's disease is a progressive and neurodegenerative disorder which involves multiple molecular mechanisms. Intense research during the last years has accumulated a large body of data and the search for sensitive and specific biomarkers has undergone a rapid evolution. However, the diagnosis remains problematic and the current tests do not accurately detect the process leading to neurodegeneration. Biomarkers discovery and validation are considered the key aspects to support clinical diagnosis and provide discriminatory power between different stages of the disorder. A considerable challenge is to integrate different types of data from new potent approach to reach a common interpretation and replicate the findings across studies and populations. Furthermore, long-term clinical follow-up and combined analysis of several biomarkers are among the most promising perspectives to diagnose and manage the disease. The present review will focus on the recent published data providing an updated overview of the main achievements in the genetic and biochemical research of the Alzheimer's disease. We also discuss the latest and most significant results that will help to define a specific disease signature whose validity might be clinically relevant for future AD diagnosis.  相似文献   
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