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   1020559篇
  免费   70929篇
  国内免费   2888篇
耳鼻咽喉   13981篇
儿科学   31726篇
妇产科学   28257篇
基础医学   141914篇
口腔科学   27351篇
临床医学   86732篇
内科学   207873篇
皮肤病学   20583篇
神经病学   82061篇
特种医学   41226篇
外国民族医学   336篇
外科学   161350篇
综合类   20752篇
现状与发展   1篇
一般理论   408篇
预防医学   75751篇
眼科学   22752篇
药学   72455篇
  2篇
中国医学   1961篇
肿瘤学   56904篇
  2021年   8164篇
  2019年   8537篇
  2018年   11708篇
  2017年   9034篇
  2016年   9693篇
  2015年   11166篇
  2014年   15947篇
  2013年   24628篇
  2012年   33599篇
  2011年   35718篇
  2010年   21270篇
  2009年   20109篇
  2008年   33656篇
  2007年   35791篇
  2006年   35599篇
  2005年   35260篇
  2004年   33794篇
  2003年   32416篇
  2002年   31805篇
  2001年   42474篇
  2000年   43467篇
  1999年   37461篇
  1998年   11431篇
  1997年   10287篇
  1996年   10178篇
  1995年   9513篇
  1994年   8958篇
  1993年   8428篇
  1992年   28915篇
  1991年   27727篇
  1990年   27059篇
  1989年   25962篇
  1988年   24158篇
  1987年   23743篇
  1986年   22880篇
  1985年   21803篇
  1984年   16593篇
  1983年   14248篇
  1982年   9090篇
  1979年   15161篇
  1978年   10814篇
  1977年   9150篇
  1976年   8614篇
  1975年   9379篇
  1974年   11114篇
  1973年   10573篇
  1972年   9927篇
  1971年   9196篇
  1970年   8822篇
  1969年   8208篇
排序方式: 共有10000条查询结果,搜索用时 51 毫秒
101.
102.
Cyanoacrylate-based glues have been reported as producing dermatitis and bronchial asthma. The paper describes the case of a patient occupationally exposed to Loctite 406, who developed irritation of the skin and mucosae of the face and late bronchial asthma. Preventive measures for subjects exposed to cyanoacrylic instant glues are discussed.  相似文献   
103.
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   
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.
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   
106.
107.
108.
Cisplatin in combination with other cytotoxic agents is the backbone for a potential cure of testicular germ cell neoplasms and is a critical factor in the substantial activity observed in the treatment of small cell lung cancer, bladder cancer, and ovarian germ cell tumors. Resistance to cisplatin at the onset of treatment or at relapse limits its curative potential, however. Laboratory studies using both cells selected for cisplatin resistance by exposure to sublethal concentrations and biopsy specimens from patients' tumors provide insights for the potential mechanisms of resistance. The mechanisms identified in vitro include a complex and wide array of related and unrelated pathways such as alterations in cellular drug transport, enhanced DNA repair dependent and independent of signal transduction pathways, and enhanced intracellular detoxification such as glutathione and metallothionein systems. Studies of these mechanisms have identified a number of agents with known potential for administration to humans and that reverse cisplatin resistance in vitro; for example, reversal of cellular accumulation defects by dipyridamole; inhibition of DNA repair by hydroxyurea, pentoxifylline, and novobiocin; inhibition of the glutathione system by ethacrynic acid and buthionine sulfoximine; and inhibition of signal transduction pathways by cyclosporine, tamoxifen, and calcium channel-blocking agents. Current phase I clinical trials are focusing on the most effective doses and schedules to administer these agents in combination with cisplatin. Initial uncontrolled trials in limited numbers of patients suggest that the addition of modulators of cisplatin has the potential to reverse resistance in patients previously failing therapy. Another promising avenue for circumventing cisplatin resistance is the development of noncross-resistant platinum analogs.  相似文献   
109.
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   
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