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   888398篇
  免费   75292篇
  国内免费   4033篇
耳鼻咽喉   13154篇
儿科学   24942篇
妇产科学   25375篇
基础医学   127088篇
口腔科学   25895篇
临床医学   78608篇
内科学   167975篇
皮肤病学   17687篇
神经病学   71518篇
特种医学   36767篇
外国民族医学   178篇
外科学   138974篇
综合类   29665篇
现状与发展   6篇
一般理论   266篇
预防医学   68505篇
眼科学   21359篇
药学   68268篇
  18篇
中国医学   3944篇
肿瘤学   47531篇
  2018年   8636篇
  2016年   7881篇
  2015年   9553篇
  2014年   13223篇
  2013年   18843篇
  2012年   25531篇
  2011年   26718篇
  2010年   15795篇
  2009年   14563篇
  2008年   24292篇
  2007年   26318篇
  2006年   26059篇
  2005年   25654篇
  2004年   24819篇
  2003年   24000篇
  2002年   22925篇
  2001年   36588篇
  2000年   37010篇
  1999年   31162篇
  1998年   8997篇
  1997年   8207篇
  1996年   8048篇
  1995年   8136篇
  1994年   7845篇
  1992年   26739篇
  1991年   26223篇
  1990年   25724篇
  1989年   24748篇
  1988年   23271篇
  1987年   22918篇
  1986年   21781篇
  1985年   21125篇
  1984年   16371篇
  1983年   13958篇
  1982年   8833篇
  1981年   8174篇
  1979年   16705篇
  1978年   12078篇
  1977年   10140篇
  1976年   9295篇
  1975年   10112篇
  1974年   12619篇
  1973年   12122篇
  1972年   11529篇
  1971年   10670篇
  1970年   10195篇
  1969年   9898篇
  1968年   8892篇
  1967年   8214篇
  1966年   7643篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
The WHO has stated that antibiotic resistance is escalating to perilously high levels globally and that traditional therapies of antimicrobial drugs are futile against infections caused by resistant microorganisms. Novel antimicrobial drugs are therefore required. We report in this study on the inhibitory activity of the 1,4-naphthoquinone-2,3-bis-sulfides and 1,4-naphthoquinone sulfides against two bacteria and a fungus to determine their antimicrobial properties. The 1,4-naphthoquinone sulfides have potent activity with a minimum inhibitory concentration (MIC) of 7.8 μg/mL against Staphylococcus aureus (Gram +ve), an MIC of 23.4 μg/mL against the fungus, Candida albicans, which was better than that of Amphotericin B (MIC = 31.3 μg/mL), and against Escherichia coli (Gram −ve) an MIC of 31.3 μg/mL was obtained. The 1,4-naphthoquinone had an MIC of 11.7 μg/mL against S. aureus and the 1,4-naphthohydroquinone also had the same activity against E. coli.
Hit, Lead & Candidate Discovery
  相似文献   
92.
Lac  Andrew  Luk  Jeremy W. 《Prevention science》2019,20(5):800-809
Prevention Science - The current study tested and identified risk and protective pathways from alcohol expectancies to weekday and weekend consumption to problematic consequences. Adult alcohol...  相似文献   
93.
94.
95.
96.

Objectives

To determine the proportion of participants of a running program for novice runners that discontinued running and investigate the main reasons to discontinue and characteristics associated with discontinuation.

Design

Prospective cohort study.

Methods

The study included 774 participants of Start to Run, a 6-week running program for novice runners. Before the start of the program, participants filled-in a baseline questionnaire to collect information on demographics, physical activity and perceived health. The 26-weeks follow-up questionnaire was used to obtain information on the continuation of running (yes/no) and main reasons for discontinuation. To determine predictors for discontinuation of running, multivariable logistic regression was performed.

Results

Within 26 weeks after the start of the 6-week running program, 29.5% of the novice runners (n = 225) had stopped running. The main reason for discontinuation was a running-related injury (n = 108, 48%). Being female (OR 1.74; 95% CI 1.13–2.68), being unsure about the continuation of running after the program (OR 2.06; 95% CI 1.31–3.24) and (almost) no alcohol use (OR 1.62; 95%CI 1.11–2.37) were associated with a higher chance of discontinuation of running. Previous running experience less than one year previously (OR 0.46; 95% CI 0.26–0.83) and a higher score on the RAND-36 subscale physical functioning (OR 0.98; 95% CI 0.96–0.99) were associated with a lower chance of discontinuation.

Conclusions

In this group of novice runners, almost one-third stopped running within six months. A running-related injury was the main reason to stop running. Women with a low perceived physical functioning and without running experience were prone to discontinue running.  相似文献   
97.
98.
99.
100.
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