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   1503023篇
  免费   140352篇
  国内免费   1655篇
  2021年   18014篇
  2019年   16269篇
  2018年   18776篇
  2017年   17559篇
  2016年   28883篇
  2015年   42816篇
  2014年   50878篇
  2013年   77170篇
  2012年   40943篇
  2011年   31160篇
  2010年   45646篇
  2009年   46510篇
  2008年   28757篇
  2007年   27138篇
  2006年   31211篇
  2005年   32573篇
  2004年   31127篇
  2003年   28934篇
  2002年   26904篇
  2001年   43671篇
  2000年   41391篇
  1999年   38726篇
  1998年   26601篇
  1997年   26551篇
  1996年   25808篇
  1995年   24035篇
  1994年   23732篇
  1993年   23052篇
  1992年   33436篇
  1991年   31888篇
  1990年   30467篇
  1989年   30933篇
  1988年   28433篇
  1987年   27150篇
  1986年   25530篇
  1985年   27532篇
  1984年   26100篇
  1983年   23034篇
  1982年   22330篇
  1981年   21252篇
  1980年   19995篇
  1979年   22207篇
  1978年   20277篇
  1977年   19294篇
  1976年   18439篇
  1975年   18293篇
  1974年   18935篇
  1973年   19158篇
  1972年   16354篇
  1971年   15055篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
We used self‐reported data from United Methodist clergy to assess the prevalence of obesity and having ever been told certain chronic disease diagnoses. Of all actively serving United Methodist clergy in North Carolina (NC) 95% (n = 1726) completed self‐report height and weight items and diagnosis questions from the Behavioral Risk Factor Surveillance Survey (BRFSS). We calculated BMI categories and diagnosis prevalence rates for the clergy and compared them to the NC population using BRFSS data. The obesity rate among clergy aged 35–64 years was 39.7%, 10.3% (95% CI = 8.5%, 12.1%) higher than their NC counterparts. Clergy also reported significantly higher rates of having ever been given diagnoses of diabetes, arthritis, high blood pressure, angina, and asthma compared to their NC peers. Health interventions that address obesity and chronic disease among clergy are urgently needed.  相似文献   
962.
963.
964.
965.
966.
967.
968.
The regulation by substrate induction of the acetohydroxy acid isomeroreductase was studied in Escherichia coli. Induction was inhibited by chloramphenicol and rifampin. The addition of rifampin resulted in a decay of the capacity to form isomeroreductase. This was attributed to the breakdown of the isomeroreductase messenger, which had a half-life of about 45 sec at 37 C. Induction of isomeroreductase was enhanced by including glucose in the medium. This effect was shown to be due in part to the lowering of the pH of the medium, which presumably made inducer entry more rapid.  相似文献   
969.
970.
Albert's method, of staining diphtheria cultures consists of staining a fixed smear for one minute (some laboratories stain for five minutes) with a solution containing toluidine blue and malachite (or methyl) green, washing with water, and applying Albert's iodine for one minute. This procedure is discussed and criticized, and in addition the mechanism of the stain is elucidated. Also, the procedure which involves staining a fixed smear for one minute with Loeffler's alkaline methylene blue solution is discussed and criticized.

To overcome the objections to the above staining methods, a different method is proposed. This consists of staining a fixed smear with an acid solution of toluidine blue, washing with water, applying Albert's iodine for one minute, washing with water, and finally applying a safranin solution for 15-20 seconds. The theoretical basis for this method is presented.  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