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   3175869篇
  免费   231378篇
  国内免费   8801篇
耳鼻咽喉   43938篇
儿科学   102354篇
妇产科学   88792篇
基础医学   447880篇
口腔科学   88896篇
临床医学   288347篇
内科学   620084篇
皮肤病学   73818篇
神经病学   260196篇
特种医学   122982篇
外国民族医学   940篇
外科学   477973篇
综合类   69568篇
现状与发展   7篇
一般理论   1193篇
预防医学   245942篇
眼科学   72145篇
药学   233179篇
  8篇
中国医学   6402篇
肿瘤学   171404篇
  2018年   34013篇
  2017年   26233篇
  2016年   30301篇
  2015年   34341篇
  2014年   47614篇
  2013年   71988篇
  2012年   95255篇
  2011年   100550篇
  2010年   60519篇
  2009年   57831篇
  2008年   94134篇
  2007年   100407篇
  2006年   101923篇
  2005年   98105篇
  2004年   94842篇
  2003年   91724篇
  2002年   88345篇
  2001年   147844篇
  2000年   151272篇
  1999年   127879篇
  1998年   37443篇
  1997年   33417篇
  1996年   33382篇
  1995年   32270篇
  1994年   29763篇
  1993年   27923篇
  1992年   101056篇
  1991年   97534篇
  1990年   94681篇
  1989年   91562篇
  1988年   84201篇
  1987年   82678篇
  1986年   77775篇
  1985年   74393篇
  1984年   55909篇
  1983年   47618篇
  1982年   28721篇
  1981年   25869篇
  1979年   51004篇
  1978年   36411篇
  1977年   30844篇
  1976年   28567篇
  1975年   30582篇
  1974年   36544篇
  1973年   34831篇
  1972年   32866篇
  1971年   30444篇
  1970年   28323篇
  1969年   27326篇
  1968年   25069篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
A case of Goldenhar’s Syndrome in a 10 year old girl is reported. The unusual features are the absence of epibulbar dermoid which is one of the major hallmarks of the Syndrome and the presence of an associated Cyanotic Heart disease.  相似文献   
993.
The present paper deals with a Finnish long-term prospective study, the objective of which is to shed light on adjustment to retirement and old age. In this phase, only the preliminary findings of the initial survey carried out in 1982 are available. For the purposes of the study, a random sample of 200 individuals was drawn from among Turku inhabitants born in 1920. Another sample, consisting of 189 persons of the same age, was drawn from rural municipalities in the neighborhood of Turku. An extensive structured psychosocial interview could be conducted with a total of 339 subjects. The research methods used included e.g. the 36-item version of Goldberg's General Health Questionnaire (GHQ). Relatively little mental disturbance was revealed in the interview, and no major differences occurred between the urban and the rural sample. Somewhat over one-third of both samples were probable psychiatric cases as defined according to the GHQ.  相似文献   
994.
Surgically-obtained tissue specimens from 41 patients with ventricular aneurysm were studied electron microscopically. The tissue from the resected aneurysms showed substantially varied morphological differences. In some, there were extensive regions of scar containing increased fibrotic material and few cells, in others there were also larger contiguous regions of myocardium with an essentially normal appearance. In the preserved myocardial regions, the cardiac cells showed moderate hypertrophy. There was an increase in contractile substance in parallel with an increase in mitochondria and enlargement of the nucleus with frequent waves and invaginations in the cell membrane. The cells at the marginal regions between fibrous tissue and preserved myocardium were frequently isolated from adjacent cells. In particular, when the isolated cells were completely surrounded by fibrous tissue, clear degeneration was apparent. These cells showed mainly a fibrillolysis with dissolution of the cross-bands and loss of the entire contractile apparatus. In compensation, occasionally there was proliferation of other cell structures, especially the free sarcoplasmatic reticulum. The hypertrophy of the still intact myocardial cells is considered compensatory for the infarct-incurred loss of tissue. The degenerative appearance is mainly attributable to fibrous tissue invasion. The diminished oxygen supply, compromised or abolished impulse conduction, loss of function and passive stretch during systole may be regarded as causes of the degeneration.  相似文献   
995.
996.
997.
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   
998.
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   
999.
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   
1000.
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   
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