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   543519篇
  免费   28646篇
  国内免费   533篇
耳鼻咽喉   6757篇
儿科学   17269篇
妇产科学   12701篇
基础医学   94415篇
口腔科学   12617篇
临床医学   49921篇
内科学   98052篇
皮肤病学   11996篇
神经病学   35354篇
特种医学   20302篇
外国民族医学   53篇
外科学   79898篇
综合类   7744篇
现状与发展   2篇
一般理论   139篇
预防医学   40184篇
眼科学   12170篇
药学   42362篇
  1篇
中国医学   1144篇
肿瘤学   29617篇
  2021年   4349篇
  2019年   4273篇
  2018年   6164篇
  2017年   4472篇
  2016年   5233篇
  2015年   5797篇
  2014年   7649篇
  2013年   11228篇
  2012年   16698篇
  2011年   18500篇
  2010年   10636篇
  2009年   9392篇
  2008年   16670篇
  2007年   18356篇
  2006年   17827篇
  2005年   17123篇
  2004年   16674篇
  2003年   15989篇
  2002年   15372篇
  2001年   22544篇
  2000年   23037篇
  1999年   18994篇
  1998年   5346篇
  1997年   4454篇
  1996年   4474篇
  1995年   4179篇
  1992年   14453篇
  1991年   15843篇
  1990年   15972篇
  1989年   15646篇
  1988年   14326篇
  1987年   14213篇
  1986年   13183篇
  1985年   12702篇
  1984年   9413篇
  1983年   8014篇
  1982年   4197篇
  1979年   8950篇
  1978年   6396篇
  1977年   5158篇
  1976年   5510篇
  1975年   6617篇
  1974年   7424篇
  1973年   7164篇
  1972年   6599篇
  1971年   6311篇
  1970年   5890篇
  1969年   5470篇
  1968年   5163篇
  1967年   4623篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
991.
992.
993.
994.
The article deals with the results of using ultrafiltration hemoconcentration in 649 operations conducted on the open heart with extracorporeal circulation at the All-Union Scientific Center of Surgery, USSR AMS during 1983-1989. The method allows control of hemodilution and colloid-osmotic pressure of plasma during the indicated interventions, lessens the loss of blood, and reduces the expenditure of donor blood.  相似文献   
995.
996.
The objective of this study was to estimate the incidence of hip fracture in the canton of Vaud, Switzerland (total population 584 000), for the period 1986–1991 using routine hospital discharge data collected by the Cantonal Service of Statistical Research and Information (SCRIS). For the survey period, the estimated average annual crude incidence rate of hip fractures was 167 per 100 000 persons aged 20 or older (241 for women and 84 for men). For the population aged 50 years or older, the crude incidence rate was 388 per 100 000 persons (546 for women and 185 for men). The average annual age-specific rates rose exponentially by successive 5-year age groups. The median age of patients at the time of the fracture was 82 years in women and 74 years in men. There was no significant difference between the total number of cervical and trochanteric fractures. Between the ages of 20 and 84 years, the cumulative risk for a woman to be admitted to hospital with a hip fracture was twice that of a man (15.8% vs 7.8%). From 1986 to 1991, the age- and sex-adjusted incidence, like the ratio of cervical to trochanteric fractures, did not show any significant trend, although it was consistent with an increase in men (p=0.09). However, the annual number of fractures rose from 644 to 776, particularly among very aged men. The mean length of stay in the acute care hospital fell from 38 days in 1986 to 25 days in 1991. Finally, the comparison of these results with those obtained in 1986 for the same population from more exhaustive sources has confirmed the provision of a consistent, although overestimated, assessment of hip fracture incidence by means of these routine hospital statistics in the canton of Vaud, Switzerland.  相似文献   
997.
998.
999.
The authors present the results of a transmission electron-microscopic study performed on a tissue sample obtained by an intraocular fine-needle aspiration biopsy in a case of retinoma. The ultrastructural study showed that the tumor was composed mainly of granular osmiophilic material which contained some tumor cells. These cells showed peculiar ultrastructural characteristics, which demonstrated their neural character, and appeared in different degenerative stages. Apparently, this is the first case in whom ultrastructural technique have been applied to study an intraocular tumor sample obtained by intraocular fine-needle aspiration biopsy, and the first case of retinoma studied by such a diagnostic approach.  相似文献   
1000.
An eye protection program is needed in occupational medicine policies. Typical eye injuries and eye accidents, as they relate to occupational accidents, justify the management advocating such a program. A recommended model for a functional eye protection program is provided and defined.  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