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   278867篇
  免费   18461篇
  国内免费   49篇
  2021年   2505篇
  2020年   2051篇
  2019年   2329篇
  2018年   4850篇
  2017年   4634篇
  2016年   5771篇
  2015年   5992篇
  2014年   7182篇
  2013年   10085篇
  2012年   11944篇
  2011年   11989篇
  2010年   8181篇
  2009年   6754篇
  2008年   10245篇
  2007年   10359篇
  2006年   9925篇
  2005年   8996篇
  2004年   9131篇
  2003年   8592篇
  2002年   8386篇
  2001年   10475篇
  2000年   10156篇
  1999年   7921篇
  1998年   2511篇
  1997年   2239篇
  1996年   2113篇
  1995年   1936篇
  1992年   5923篇
  1991年   6066篇
  1990年   5999篇
  1989年   5957篇
  1988年   5543篇
  1987年   5169篇
  1986年   4735篇
  1985年   4976篇
  1984年   3998篇
  1983年   3217篇
  1982年   2195篇
  1979年   3508篇
  1978年   2725篇
  1977年   2496篇
  1976年   2426篇
  1975年   2983篇
  1974年   3298篇
  1973年   3275篇
  1972年   2902篇
  1971年   2750篇
  1970年   2356篇
  1969年   2294篇
  1968年   2166篇
排序方式: 共有10000条查询结果,搜索用时 484 毫秒
991.
992.
Two cases of squamous cell carcinoma of the prepuce arising on balanitis xerotica obliterans are described. This event is unusual and not well known. The surgical treatment was a wide circumcision in which the prepuce and part of the shaft skin were removed, performing as well a decortication of the glans base. This technique seemed to be satisfactory in removing the carcinoma and obtaining a definite improvement in the clinical picture of balanitis xerotica obliterans as well.  相似文献   
993.
It has been found that lymphocytes of hypercholesterolemic (HCh) subjects are characterized by a reduced number of glucocorticoid receptors (GcR) as compared with the cells of normolipidemics (N). Addition of HCh-sera or very low density lipoproteins, or low density lipoproteins isolated both from HCh-sera and N-sera to cultured human skin fibroblasts brought about a fall in the number of GcR in the cells. High density lipoproteins had no effect on GcR level. Dexamethasone was less effective in inhibiting cholesterol synthesis from [14C]acetate in the lymphocytes and fibroblasts with a reduced number of GcR. In the presence of dexamethasone (I x 10(-8)M) in fibroblast growth medium, reduced number of GcR (due to preincubation with very low density lipoproteins) led to a substantial increase in cholesterol synthesis. These findings indicate that the sensitivity of peripheral cells to glucocorticoids is decreased in HCh which might be one of the trigger mechanisms of atherogenesis.  相似文献   
994.
995.
996.
997.
998.
999.
1000.
In several geographic populations of the Arctic ground squirrel C. parryi, studies have been made on changes in oxygen consumption during decrease of the ambient temperature from 25 to 3-4 degrees, thermal preference, hemoglobin content of the blood and composition of the adipose tissue (both brown and white, subcutaneous and visceral). Significant shifts of these indices were found. In animals from various parts of the species area, different sensitivity to cooling was found, as indicated by determinations of oxygen consumption at different temperatures and the prefered temperature: different hemoglobin content of the blood was also found together with differences in the level of two unsaturated fatty acids - the oleic and linoleic ones. Comparison of these data with similar results obtained on various populations of the Siberian ground squirrel C. undulatus revealed obvious differences between these close species with respect to the indices studied.  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