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   1056082篇
  免费   73015篇
  国内免费   3138篇
耳鼻咽喉   14278篇
儿科学   32504篇
妇产科学   28935篇
基础医学   146954篇
口腔科学   28444篇
临床医学   90152篇
内科学   215634篇
皮肤病学   22132篇
神经病学   86107篇
特种医学   43121篇
外国民族医学   349篇
外科学   166341篇
综合类   21690篇
一般理论   346篇
预防医学   76318篇
眼科学   23544篇
药学   73921篇
  4篇
中国医学   2188篇
肿瘤学   59273篇
  2021年   9235篇
  2019年   9492篇
  2018年   12617篇
  2017年   9968篇
  2016年   10801篇
  2015年   12368篇
  2014年   17418篇
  2013年   26001篇
  2012年   35634篇
  2011年   38055篇
  2010年   22927篇
  2009年   21755篇
  2008年   35605篇
  2007年   37712篇
  2006年   37701篇
  2005年   37161篇
  2004年   35288篇
  2003年   33790篇
  2002年   32993篇
  2001年   43630篇
  2000年   44517篇
  1999年   38464篇
  1998年   11865篇
  1997年   10687篇
  1996年   10358篇
  1995年   9653篇
  1994年   9197篇
  1993年   8585篇
  1992年   29482篇
  1991年   28198篇
  1990年   27457篇
  1989年   26358篇
  1988年   24486篇
  1987年   24045篇
  1986年   23132篇
  1985年   22033篇
  1984年   16705篇
  1983年   14263篇
  1982年   8993篇
  1979年   15235篇
  1978年   10831篇
  1977年   9143篇
  1976年   8641篇
  1975年   9420篇
  1974年   11214篇
  1973年   10636篇
  1972年   10074篇
  1971年   9243篇
  1970年   8897篇
  1969年   8302篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Patient history and clinical examination are important for the diagnosis of degenerative joint disease. Here the typical statements of a patient suffering from early osteoarthritis are described and, as far as possible, explained. The joint in question must be systematically examined. Furthermore, the neighboring joints and soft-tissue structures, i.e., muscles, tendons etc., should be examined and evaluated with respect to their importance in hindering the functional chain. The neuroreflectory mechanisms involved herein are described.  相似文献   
103.
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   
104.
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   
105.
106.
Our study was intended to determine whether power Doppler sonography can be considered superior to color Doppler technique in depiction of normal orbital vasculature. Ten healthy volunteers (20 eyes) were examined with a 10 MHz linear probe; each orbital vessel was recorded with both color and power Doppler methods; the images were reviewed independently by all the observers, who agreed that power Doppler clearly is superior to color Doppler technique for evaluation of the anatomy of orbital arteries and veins.  相似文献   
107.
108.
Cultured keratinocytes were used as allografts on burn wounds in two patients. In both patients successful covering of the wounds was obtained. DNA fingerprinting of the epidermis covering the wounds 21 days later showed that the cultured keratinocytes were replaced by the patients' cells.  相似文献   
109.
Free-floating clots of the extracranial internal carotid artery are generally considered as surgical emergencies. This retrospective study analyzes six free-floating clots diagnosed by arteriography. Three of these patients had a fixed stroke while the other three had an evolving stroke. Three patients had antecedent ocular or hemispheric transient ischemic attacks. The causes of free-floating clots in the internal carotid artery were atheromatous stenosis in two cases, ulcerated plaque in three cases, and carotid artery dissection in one. All six patients were seen late, approximately 15 hours after their neurologic accident. They were treated with intravenous heparin over a two to five week period. Repeat arteriograms demonstrated complete clot lysis in four instances, while partial lysis was seen in one case. Moderate extension of thrombus occurred in one case only. No further neurologic complications were noted during the treatment by heparin. As indicated by follow-up arteriographic findings, secondary surgery was performed for major carotid lesions and residual clots in five cases. The free-floating thrombus syndrome of the carotid artery should not be considered as a surgical emergency when discovered late in the wake of an acute neurologic accident.  相似文献   
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