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   3381534篇
  免费   239784篇
  国内免费   8795篇
耳鼻咽喉   46876篇
儿科学   112199篇
妇产科学   94957篇
基础医学   478303篇
口腔科学   94496篇
临床医学   304069篇
内科学   660545篇
皮肤病学   79151篇
神经病学   273866篇
特种医学   130891篇
外国民族医学   1047篇
外科学   510149篇
综合类   69471篇
现状与发展   6篇
一般理论   1192篇
预防医学   258173篇
眼科学   76927篇
药学   249425篇
  9篇
中国医学   6797篇
肿瘤学   181564篇
  2018年   36140篇
  2017年   27616篇
  2016年   31956篇
  2015年   36111篇
  2014年   49740篇
  2013年   75104篇
  2012年   100050篇
  2011年   106212篇
  2010年   63969篇
  2009年   61170篇
  2008年   99946篇
  2007年   106619篇
  2006年   108607篇
  2005年   104511篇
  2004年   100683篇
  2003年   97457篇
  2002年   94590篇
  2001年   158024篇
  2000年   161945篇
  1999年   136940篇
  1998年   39751篇
  1997年   35258篇
  1996年   35514篇
  1995年   34178篇
  1994年   31632篇
  1993年   29675篇
  1992年   108020篇
  1991年   104693篇
  1990年   101933篇
  1989年   98774篇
  1988年   90979篇
  1987年   89332篇
  1986年   84275篇
  1985年   80539篇
  1984年   59844篇
  1983年   51381篇
  1982年   30608篇
  1981年   27189篇
  1979年   54266篇
  1978年   38301篇
  1977年   32828篇
  1976年   30589篇
  1975年   33007篇
  1974年   38868篇
  1973年   37105篇
  1972年   35177篇
  1971年   32578篇
  1970年   30397篇
  1969年   29179篇
  1968年   27050篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
93.
94.
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.  相似文献   
95.
PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads.  相似文献   
96.
Cell physiology and molecular biology typically follow a reductionistic approach in science. In the last decade, molecular principles and pathogenetic factors involved in the development of many diseases have been successfully discovered. Therefore, early biological concepts based on systemic and cybernetic thoughts have been largely overshadowed by these more recent molecular and pathogenetic factors. This review highlights discoveries on bone development and hypothalamic controlled feeding and eating behavior with a cybernetic and systemic perspective. Interestingly, ancient ideas on bone development and hypothalamic function are still reasonable considerations to embed new molecular discoveries into a systemic concept of principles organizing nature.  相似文献   
97.
98.
Bifid mandibular canal.   总被引:1,自引:0,他引:1  
PURPOSE: To determine the incidence and characteristics of bifid mandibular canals. METHODS: A retrospective study was performed using panoramic radiographs of 2012 patients subjected to dental treatment in the Dental Clinic of the Valencia University Dental School (Valencia, Spain) between 1996 and 1999. The goal was to investigate the presence of double mandibular canals. RESULTS: The extraoral panoramic radiographs revealed a total of 7 images suggestive of bifid canals. Mandibular computed tomography revealed the existence of this anatomic variant in 2 of 3 patients. An analysis was performed on the incidence of this type of image in extraoral panoramic radiography, its possible interpretations, and the clinical implications of bifid mandibular canals. CONCLUSIONS: In this study, 0.35% of canals were bifid. All cases were in women.  相似文献   
99.
G Pauletto  P Bergonzi 《Seizure》2006,15(3):150-155
The antiepileptic efficacy and tolerability of oxcarbazepine, used both as monotherapy and adjunctive therapy, were observed for 1 year in 202 adult patients, aged 17-83 years, with newly diagnosed or refractory partial epilepsy in clinical practice in Italy. At first observation, the seizure free rate was 72.2% in newly diagnosed patients given monotherapy, 40% in patients in whom oxcarbazepine replaced another monotherapy and 10.3% in patients given oxcarbazepine as adjunctive therapy. At least 50% reduction in seizure frequency was achieved in 90.7, 72 and 57%, respectively. Efficacy increased with the duration of treatment (p < 0.0001). In the 160 completers the seizure free rate was 61.3% with monotherapy and 28% with adjunctive therapy. 16.3% of patients reported adverse effects, mainly sedation and sleepiness; 5% discontinued oxcarbazepine because of adverse events. OXC is an effective and well-tolerated antiepileptic agent for the long-term treatment of partial epilepsy in adults.  相似文献   
100.
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