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   13014篇
  免费   1325篇
  国内免费   33篇
耳鼻咽喉   260篇
儿科学   384篇
妇产科学   292篇
基础医学   1667篇
口腔科学   338篇
临床医学   1536篇
内科学   2744篇
皮肤病学   214篇
神经病学   935篇
特种医学   461篇
外科学   1842篇
综合类   603篇
一般理论   7篇
预防医学   1320篇
眼科学   208篇
药学   906篇
中国医学   6篇
肿瘤学   649篇
  2021年   180篇
  2020年   134篇
  2019年   189篇
  2018年   193篇
  2017年   179篇
  2016年   152篇
  2015年   247篇
  2014年   262篇
  2013年   401篇
  2012年   547篇
  2011年   543篇
  2010年   323篇
  2009年   302篇
  2008年   495篇
  2007年   563篇
  2006年   548篇
  2005年   528篇
  2004年   528篇
  2003年   521篇
  2002年   475篇
  2001年   402篇
  2000年   483篇
  1999年   374篇
  1998年   186篇
  1997年   170篇
  1996年   179篇
  1995年   146篇
  1994年   131篇
  1993年   101篇
  1992年   303篇
  1991年   295篇
  1990年   269篇
  1989年   277篇
  1988年   234篇
  1987年   226篇
  1986年   262篇
  1985年   230篇
  1984年   193篇
  1983年   145篇
  1982年   129篇
  1979年   183篇
  1978年   119篇
  1977年   120篇
  1976年   99篇
  1975年   120篇
  1974年   145篇
  1973年   135篇
  1972年   141篇
  1971年   121篇
  1970年   110篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
31.
Dural sinus thrombosis: study using intermediate field strength MR imaging   总被引:1,自引:0,他引:1  
The magnetic resonance (MR) images of six patients with thrombosis of a dural sinus were reviewed. The diagnosis had been verified by computed tomographic scans in three patients and arteriograms in two; in the sixth patient, only MR imaging was used to confirm the clinical syndrome. In all patients, high-intensity signal was seen from the thrombus within the affected dural sinus on all echoes. This persistent signal intensity allowed intravascular clot to be distinguished from normal causes of increased signal such as flow-related enhancement (entry phenomenon) and even-echo rephasing. MR imaging demonstrated the cause of the thrombosis in three patients: two were secondary to adjacent tumors, and one was secondary to unsuspected mastoiditis. Complications such as infarction were also demonstrated. Using MR imaging, one can easily and safely diagnose thrombosis of a dural sinus. MR should be the imaging method of choice in patients suspected of having thrombosis of a dural sinus.  相似文献   
32.
Effects of antidepressant medication on sexual function: a controlled study   总被引:3,自引:0,他引:3  
There has been little systematic study of the types of sexual dysfunction produced by antidepressant medication or of the frequency with which this type of adverse effect occurs. The authors report results of a double-blind study in which the effects of imipramine, phenelzine, and placebo on specific aspects of sexual function were assessed in depressed outpatients before and after 6 weeks of treatment. Both active treatments were associated with a high incidence of adverse changes in sexual function and produced significantly more adverse effects on sexual function than placebo. Orgasm and ejaculation were impaired to a greater extent than erection. Adverse sexual function changes secondary to antidepressant medication occurred frequently in both men and women, although men reported a higher incidence. Antidepressant-related sexual dysfunction may be of clinical importance for medication compliance in view of current recommendations that antidepressants be administered for longer periods as maintenance therapy or for prophylaxis.  相似文献   
33.
The techniques specific to peroperative fluorocholangiography are discussed based on an experience of 632 cholangiograms and an estimation has been made of the associated radiation doses to staff and patients. Rapid and accurate information can be obtained during fluorocholangiography using appropriate techniques with acceptably low radiation hazards.  相似文献   
34.
35.
A total of 1786 blood donors were screened for the presence of anti-hepatitis A antibody (anti HAV). 64.5% of the donors were found to be positive. The prevalence of the antibody was found to be age-related, 55% at 18 years and 75% at 65 years. No relationship was noted between the presence of antibody, foreign travel or a specific destination. Assay of antibody levels in selected seropositive individuals gave a mean level of 5.0 IU/ml. The prevalence of infection in this selected population is important in the context of passive immunization with normal human immunoglobulin and for defining a policy of immunization with hepatitis A vaccines, which are currently undergoing clinical trials.  相似文献   
36.
37.
38.
OBJECTIVE: The role of apical versus basal cochlear implant electrode stimulation on central auditory development was examined. We hypothesized that, in children with early onset deafness, auditory development evoked by basal electrode stimulation would differ from that evoked more apically. METHODS: Responses of the auditory nerve and brainstem, evoked by an apical and a basal implant electrode, were measured over the first year of cochlear implant use in 50 children with early onset severe to profound deafness who used hearing aids prior to implantation. RESULTS: Responses at initial stimulation were of larger amplitude and shorter latency when evoked by the apical electrode. No significant effects of residual hearing or age were found on initial response amplitudes or latencies. With implant use, responses evoked by both electrodes showed decreases in wave and interwave latencies reflecting decreased neural conduction time through the brainstem. Apical versus basal differences persisted with implant experience with one exception; eIII-eV interlatency differences decreased with implant use. CONCLUSIONS: Acute stimulation shows prolongation of basally versus apically evoked auditory nerve and brainstem responses in children with severe to profound deafness. Interwave latencies reflecting neural conduction along the caudal and rostral portions of the brainstem decreased over the first year of implant use. Differences in neural conduction times evoked by apical versus basal electrode stimulation persisted in the caudal but not rostral brainstem. SIGNIFICANCE: Activity-dependent changes of the auditory brainstem occur in response to both apical and basal cochlear implant electrode stimulation.  相似文献   
39.
OBJECTIVES--To describe the types and circumstances of traumatic work related fatalities in Australian commercial fishermen. METHODS--Work related traumatic fishing fatalities were studied as part of a larger study of all work related traumatic fatalities in Australia from 1982 to 1984. Data on 47 cases were obtained from inspection of coroners' files. RESULTS--The incidence of fatality of 143/100,000 person-years was 18 times higher than the incidence of fatality for the entire workforce, and considerably higher than that of the mining and agricultural workforces. 68% of decedents drowned and 13% died from physical trauma. Rough weather, non-seaworthy vessels, inadequate use of personal flotation devices, and inexperience were associated with many of the fatal incidents. DISCUSSION--Improved vessel and equipment maintenance, better training of workers, greater use of personal flotation devices, and development of improved clothing and personal flotation devices are recommended.  相似文献   
40.
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