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   1279490篇
  免费   92912篇
  国内免费   1993篇
耳鼻咽喉   18246篇
儿科学   42350篇
妇产科学   37875篇
基础医学   187379篇
口腔科学   35440篇
临床医学   108393篇
内科学   251965篇
皮肤病学   26562篇
神经病学   99414篇
特种医学   50045篇
外国民族医学   366篇
外科学   197974篇
综合类   26559篇
现状与发展   1篇
一般理论   302篇
预防医学   92975篇
眼科学   29114篇
药学   97996篇
  1篇
中国医学   2501篇
肿瘤学   68937篇
  2018年   11868篇
  2015年   11676篇
  2014年   16069篇
  2013年   24452篇
  2012年   33721篇
  2011年   36119篇
  2010年   21330篇
  2009年   20105篇
  2008年   35119篇
  2007年   38090篇
  2006年   38629篇
  2005年   37912篇
  2004年   36497篇
  2003年   35476篇
  2002年   35021篇
  2001年   58165篇
  2000年   59658篇
  1999年   50753篇
  1998年   14264篇
  1997年   12831篇
  1996年   13096篇
  1995年   12369篇
  1994年   11775篇
  1993年   10883篇
  1992年   41035篇
  1991年   40403篇
  1990年   39919篇
  1989年   38748篇
  1988年   36144篇
  1987年   35392篇
  1986年   33765篇
  1985年   32173篇
  1984年   23950篇
  1983年   20851篇
  1982年   12390篇
  1981年   10944篇
  1980年   10218篇
  1979年   22653篇
  1978年   15893篇
  1977年   13741篇
  1976年   12983篇
  1975年   14215篇
  1974年   16695篇
  1973年   16086篇
  1972年   15332篇
  1971年   14239篇
  1970年   13229篇
  1969年   12738篇
  1968年   11985篇
  1967年   10486篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Blood histamine levels were measured by the bioassay of histamine (on an isolated strip of guinea pig ileum) in workers exposed to cotton dust in a textile mill in Ahmedabad. Byssinotic subjects showed very high levels of blood histamine as compared to nonbyssinotic and control subjects. The blood histamine levels were not well correlated to the dust concentrations or duration of exposure but rather to the day of the week (ie, first, second, third, etc., after weekend break) on which the samples were collected. The blood histamine levels were high on the first day of the work week, when byssinotics complained most of their symptoms.  相似文献   
992.
An early accurate diagnosis of subungual melanoma depends upon an alert podiatric physician. Clinically, the lesion is often easily misdiagnosed and mistreated because of its resemblance to benign nail conditions. This paper discusses the incidence, histology, clinical findings, diagnosis, and treatment of this malignant lesion. An illustrative case report is presented.  相似文献   
993.
The vastly increased use of prescribed and nonprescribed drugs in this society means that even such traditional social work activities as assessment and advocacy now frequently require a knowledge of the effects of drugs. Integrating a knowledge of basic concepts of pharmacology into practice will enable the social worker to help clients more effectively and to improve the health care they receive.  相似文献   
994.
995.
Seventy-four patients with impaired renal function were investigated by ultrasound. By assessing renal length, renal echogenicity and collecting system dilatation, one can establish whether renal function is impaired by chronic or acute renal changes or by obstructive changes.  相似文献   
996.
997.
998.
A Comparison of mortality from ischaemic heart disease underthe age of 60 for 1980 to 1981 between the Grampian Health Boardand the North Staffordshire Health Authority has been made.A total of 993 deaths was notified by death certificate fromthe two areas of similar population of which 434 were from Grampianand 559 from North Staffordshire. After examination of generalpractitioner and hospital case notes, autopsy reports and deathcertificates, nearly all (532) of the North Staffordshire deathswere accepted as being due to ischaemic heart disease but onlythree-fifths (263) of the Grampian deaths could be begin besubstantiated as there was inadequate information for the remainder.Deaths from ischaemic heart disease seem apparently to be twofoldgreater in North Staffordshire than Grampian but much of thisdiscrepancy could be attributed to a widely different autopsyrate and to unavailability of case notes. Experience of thissurvey suggests that the results of other epidemiological investigationsmay be equally or even more unreliable.  相似文献   
999.
The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.  相似文献   
1000.
The hormonal compound with the highest cytostatic activity against MCF-7 tumor cells (human breast cancer, BC) and the lowest activity against normal cells (rat skin fibroblasts) was sought among gestagens, androstenes, and antiestrogencytostatics. It was found that antiestrogencytostatics and androstenes had the highest cytostatic activity against tumor cells whereas gestagens and antiestrogencytostatics were least active against fibroblasts. Studies of the activity of the hormonal compounds in combination with doxorubicin on the viability of MCF-7 and rat skin fibroblasts found that all investigated compounds with the exception of dehydroepiandrosterone (DHEA) intensify the cytostatic activity of doxorubicin against tumor cells, the greatest effect seen for antiestrogencytostatics. A chemoprotective effect of androstenes on normal cells was noted. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 7, pp. 3–7, July, 2007.  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