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   3253213篇
  免费   240537篇
  国内免费   5718篇
耳鼻咽喉   44787篇
儿科学   106271篇
妇产科学   89747篇
基础医学   473880篇
口腔科学   89793篇
临床医学   296064篇
内科学   627837篇
皮肤病学   73003篇
神经病学   260163篇
特种医学   121713篇
外国民族医学   905篇
外科学   487752篇
综合类   72105篇
现状与发展   15篇
一般理论   1198篇
预防医学   257267篇
眼科学   75849篇
药学   238804篇
  11篇
中国医学   6869篇
肿瘤学   175435篇
  2021年   25775篇
  2019年   26591篇
  2018年   36924篇
  2017年   27794篇
  2016年   31383篇
  2015年   35246篇
  2014年   50055篇
  2013年   75090篇
  2012年   102825篇
  2011年   109805篇
  2010年   65009篇
  2009年   61565篇
  2008年   102245篇
  2007年   108748篇
  2006年   109922篇
  2005年   106695篇
  2004年   102253篇
  2003年   98063篇
  2002年   94717篇
  2001年   150351篇
  2000年   154101篇
  1999年   129236篇
  1998年   37785篇
  1997年   33440篇
  1996年   33496篇
  1995年   31632篇
  1994年   29186篇
  1993年   27413篇
  1992年   99445篇
  1991年   96565篇
  1990年   93874篇
  1989年   90430篇
  1988年   83282篇
  1987年   81300篇
  1986年   76231篇
  1985年   73161篇
  1984年   54933篇
  1983年   46674篇
  1982年   28112篇
  1979年   50098篇
  1978年   35576篇
  1977年   29636篇
  1976年   28263篇
  1975年   30009篇
  1974年   36240篇
  1973年   34532篇
  1972年   32542篇
  1971年   30478篇
  1970年   28352篇
  1969年   26812篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A human factors engineering analysis of a chemical containment laboratory was performed to develop appropriate standards for future laboratory design. In order to perform this evaluation, a state-of-the-art facility was studied in depth. Measurements and observations were made of key operating areas. In addition, technicians were observed and interviewed as they performed various tasks. Compiled data were compared to existing ergonomic standards. The occupational implications of instituting ergonomically developed laboratory design standards are as follows: increased worker health, safety and productivity, improved work quality and reduced stress.  相似文献   
992.
993.
A 43-year-old alcoholic presented in coma with ketoacidosis, after three days of nausea and feeling generally unwell, which had been preceded by a prolonged three-week period of heavy alcohol consumption with poor dietary intake. The acidosis responded rapidly to intravenous dextrose. This is the first Scottish report of a case of alcoholic ketoacidosis.  相似文献   
994.
Summary The authors report 165 cases of thoraco-lumbar lesions with neurological dysfunction. All the patient were operated. They analyze the neurological and mechanical results and indicate the use of different osteosynthesis apparatus according to the type and level of lesions.Harrington's rods seem to give more precise repositioning while Roy Camille's plates give more stability. When the posterior wall of the spinal canal is intact, Kempf's compression rods can be used.Thoraxic spine injuries seem to be an indication for Harrington's rods, while lumbar injuries seem to call for Camille's plates.  相似文献   
995.
Intrathecal morphine for post-thoracotomy pain   总被引:1,自引:0,他引:1  
We wished to investigate possible differences in the duration of postoperative analgesia and the incidence of respiratory depression after the intrathecal injection in the lumbar area of 10 micrograms/kg morphine in hypobaric and hyperbaric solution for relief of post-thoracotomy pain. Twenty-nine patients received morphine plus dextrose (hyperbaric) and 21 received morphine in preservative-free normal saline. The duration of analgesia was longer with the morphine in the normal saline group than in the hyperbaric group (P less than 0.04). One patient developed delayed respiratory depression. Our data support the use of morphine in normal saline mixtures for greater duration of analgesia after thoracic operations.  相似文献   
996.
Amplification of the graft-versus-host reaction by partial body irradiation   总被引:1,自引:0,他引:1  
An experimental model has been developed for the study of combined effects of partial body irradiation (PBI) and graft-versus-host disease (GVHD) in which irradiation is delivered to the thorax 24 hr prior to induction of GVHD in hybrid mice by the injection of parental lymphoid cells. In mice irradiated to 1000 cGy or exposed to low doses of allogeneic lymphoid cells (20 X 10(6)), survival was 100% at 250 days. In contrast, combination of the two treatments, GVHD and PBI, resulted in a mortality of 83% and a mean survival time of 29 days, indicating synergy between GVHD and PBI. From histological studies of the lung it appeared that about 40% of the deaths occurring after combined GVHD/PBR treatment might be attributable to pneumonia. The cause of death in the remaining mice receiving combined treatment is not known. Mice receiving combined PBI/lymphoid cell treatment develop a characteristic skin lesion that is not seen in nonirradiated mice and is confined to the irradiated area. The effect of preinduction PBR on the timing and severity of GVHD is similar to that which would be produced by an increase in the number of effector cells.  相似文献   
997.
B Lalor  A Freemont  S Carlile 《BONE》1986,7(4):273-276
Transilial crest bone biopsy with quantitative histomorphometry is an important technique for the assessment of metabolic and endocrine bone disease. The surface area of the histologic section suitable for histomorphometric analysis is reduced by the build-up of bone dust and by trabecular fracture, produced by the conventional Bordier bone drill. We describe here a modification of this drill that both allows escape of dust from around the cutting edge of the teeth and greatly reduces bone dust volume and trabecular fracture. In paired samples the new drill was shown to improve significantly the quality of the biopsy specimens.  相似文献   
998.
999.
Socio-medical indicators of health in South Africa   总被引:3,自引:0,他引:3  
Socio-medical indicators developed by WHO for monitoring progress towards Health-for-All have been adapted to reveal, clearly and objectively, the devastating impact of state planning based on an outmoded immoral and unscientific philosophy of race superiority in South Africa on the health of the disenfranchised majority within the context of social and economic discrimination; Health policy indicators confirm that the government is committed to three options (Bantustans, A New Constitution, and A Health Services Facilities Plan) all of which are inconsistent with the attainment of Health-for-All; Social and economic indicators reveal gross disparities between African, Coloured, Indian, and White living and working conditions; Provision of health care indicators show the overwhelming dominance of high technology curative medical care consuming about 97 percent of the health budget with only minor shifts towards community-based comprehensive care; and Health status indicators illustrate the close nexus between privilege, dispossession and disease with Whites falling prey to health problems related to affluence and lifestyle, while Africans, Coloureds, and Indians suffer from disease due to poverty. All four categories of the indicator system reveal discrepancies which exist between Black and White, rich and poor, urban and rural. To achieve the social goal of Health-for-All requires a greater measure of political commitment from the state. We conclude that it is debatable whether a system which maintains race discrimination and exploitation can in fact be adapted to provide Health-for-All.  相似文献   
1000.
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