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   1195029篇
  免费   84047篇
  国内免费   3838篇
耳鼻咽喉   16966篇
儿科学   30960篇
妇产科学   30732篇
基础医学   171296篇
口腔科学   36337篇
临床医学   103024篇
内科学   235191篇
皮肤病学   25434篇
神经病学   91998篇
特种医学   45958篇
外国民族医学   161篇
外科学   191232篇
综合类   26428篇
现状与发展   2篇
一般理论   287篇
预防医学   75103篇
眼科学   28839篇
药学   94035篇
  4篇
中国医学   3908篇
肿瘤学   75019篇
  2018年   12551篇
  2017年   9752篇
  2016年   10577篇
  2015年   12005篇
  2014年   16532篇
  2013年   23501篇
  2012年   32190篇
  2011年   33390篇
  2010年   19777篇
  2009年   18903篇
  2008年   31910篇
  2007年   33883篇
  2006年   34259篇
  2005年   32595篇
  2004年   31300篇
  2003年   30007篇
  2002年   29277篇
  2001年   72308篇
  2000年   74155篇
  1999年   61544篇
  1998年   14519篇
  1997年   12527篇
  1996年   12204篇
  1995年   11408篇
  1994年   10440篇
  1993年   9628篇
  1992年   45522篇
  1991年   43123篇
  1990年   41467篇
  1989年   40554篇
  1988年   36781篇
  1987年   35816篇
  1986年   33366篇
  1985年   31643篇
  1984年   22357篇
  1983年   18812篇
  1982年   9732篇
  1981年   8381篇
  1979年   19553篇
  1978年   13027篇
  1977年   11206篇
  1976年   9573篇
  1975年   10547篇
  1974年   12738篇
  1973年   12002篇
  1972年   11423篇
  1971年   10911篇
  1970年   10283篇
  1969年   9732篇
  1968年   8870篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Eleven patients with lunatomalacia were treated by excision of the lunate and instillation of liquid silicone. The silicone vulcanised and formed an in-situ molded prosthesis. The patients were reexamined after a mean of 7.1 years. Four patients were pain-free and two had pain only at work; three had not been improved by the operation and two had undergone arthrodesis. The patients with good results all belonged to group IV pre-operatively. Surprisingly, no patient showed any sign of silicone synovitis, although all the prostheses except one had either fractured or deformed. The reasons for this are discussed and the indications for the operation established.  相似文献   
102.
103.
Excision of the rectum should take in account that the main lymphatic spread follows the cranial route and that dissection of the rectal wall should be performed across its adjacent anatomical lamellae. It is not clear whether an extensive pelvic dissection and high ligature of the inferior mesenteric artery are beneficial. Spontaneous or iatrogenic perforation of the tumour considerable increases the incidence of local recurrence. The frequency of postoperative urinary and sexual dysfunction ranges from 3.5-57% and 14-38% respectively. The reported surgical mortality averages 5-6%.  相似文献   
104.
BACKGROUND: The aim was to determine the influence of the socioeconomic status of the family and the hygienic practices in the home on the prevalence of head lice infestation in children. METHODS: The study was carried out by analyzing the answers to a standardized epidemiological questionnaire given to parents of school children aged 4-17 in Bet Shemesh, a medium-sized urban town 25 km from Jerusalem. RESULTS: Of 3,000 questionnaires distributed, 958 (31.9%) were completed and returned. The majority of the children (72.4%) had been previously infested with lice. Half of them had other family members, mainly brothers and sisters, who had been infested in the past with lice. In 97.5% of the families the mother was responsible for examining the children for lice, and for carrying out treatment when infestation was present. An association was found between presence of lice infestation and mother's education, age of child, and frequency of shampooing, combing, and examination for lice. There was no association between infestation rates and mother's country of origin, crowding in the home, and the sharing of combs, brushes, hats, scarves, towels, and clothes. CONCLUSIONS: There is evidence that the incidence of lice infestation depends on the hygienic practices in the home rather than on the socioeconomic status of the family or sharing of personal articles among family members.  相似文献   
105.
Summary A case of bilateral congenital pseudarthrosis of the clavicle in a baby boy is described. The patient is fully asymptomatic, and no functional impairment is present. This is probably only the seventh case described of this rare congenital anomaly.  相似文献   
106.
Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO2), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on unruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO2 or CBV. The increase in OEF was caused by decrease of O2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO2, in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used.  相似文献   
107.
108.
109.
110.
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