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   1094篇
  免费   114篇
  国内免费   47篇
耳鼻咽喉   6篇
儿科学   75篇
妇产科学   31篇
基础医学   112篇
口腔科学   37篇
临床医学   178篇
内科学   234篇
皮肤病学   27篇
神经病学   57篇
特种医学   159篇
外科学   99篇
综合类   25篇
预防医学   79篇
眼科学   12篇
药学   58篇
  1篇
中国医学   9篇
肿瘤学   56篇
  2024年   3篇
  2023年   3篇
  2022年   3篇
  2021年   13篇
  2020年   11篇
  2019年   7篇
  2018年   24篇
  2017年   25篇
  2016年   26篇
  2015年   32篇
  2014年   40篇
  2013年   46篇
  2012年   21篇
  2011年   30篇
  2010年   46篇
  2009年   68篇
  2008年   32篇
  2007年   53篇
  2006年   26篇
  2005年   34篇
  2004年   20篇
  2003年   24篇
  2002年   14篇
  2001年   25篇
  2000年   19篇
  1999年   24篇
  1998年   74篇
  1997年   82篇
  1996年   58篇
  1995年   51篇
  1994年   38篇
  1993年   44篇
  1992年   14篇
  1991年   9篇
  1990年   15篇
  1989年   26篇
  1988年   27篇
  1987年   29篇
  1986年   16篇
  1985年   19篇
  1984年   11篇
  1983年   13篇
  1982年   10篇
  1981年   8篇
  1980年   9篇
  1978年   5篇
  1977年   11篇
  1976年   5篇
  1975年   2篇
  1930年   1篇
排序方式: 共有1255条查询结果,搜索用时 15 毫秒
91.
Study objective: To determine the effectiveness of life support courses for health care providers on the basis of one of three outcomes: (1) patient mortality and morbidity, (2) retention of knowledge or skills, and (3) change in practice behavior. Methods: English-language articles from 1975 to 1992 were identified through MEDLINE and ERIC searches, bibliographies of articles, and current abstracts. Studies were considered relevant if they included a study population of life support providers, an intervention of any of the identified life support courses, and assessment of at least one of the three listed outcomes. Relevant studies were selected and validity scores were assigned to them by agreement of two independent reviewers, using a structured form to assess validity. Data on setting, methods, participants, intervention, and outcomes were then abstracted and verified. Results: Seventeen of 67 identified studies pertaining to life support courses met the inclusion criteria. (1) All three mortality and morbidity studies indicated a positive impact, with an overall odds ratio of .28 (95% confidence interval [CI], .22 to .37). (2) No net increase in scores was found in 5 of 8 studies of retention of knowledge and in 8 of 9 studies of skills retention. Two of three studies reporting refresher activities yielded positive effects on knowledge retention. Outcomes were not significantly different between groups taught with modular or didactic techniques. (3) Studies assessing behavioral outcome were methodologically weak. Conclusion: Among providers, retention of knowledge and skills acquired by participation in support courses is poor. However, refresher activities increase knowledge retention. Modular courses are as good as lectures for learning course material. There is evidence that use of the Advanced Trauma Life Support course has decreased mortality and morbidity. Further studies of patient outcome and provider behaviors are warranted. [Jabbour M, Osmond MH, Klassen TP: Life support courses: Are they effective? Ann Emerg Med December 1996;28:690-698.]  相似文献   
92.
Seventeen AIDS patients were enrolled in a prospective open-label dose-finding study of octreotide (Sandostatin) therapy for refractory diarrhea. Five were nonevaluable due to progression of AIDS symptomatology, and one was excluded because of lack of confirmation of HIV infection. Five of 11 evaluable patients responded to therapy (45%); two each at 50 g and 100 g, and one at 250 g thrice daily doses. A sixth patient demonstrated a moderate reduction in stool volume at 250 g thrice daily, which, although deemed clinically relevant, did not meet the criteria for response. On discontinuation of therapy, diarrhea recurred in all patients within 1–12 days, and responded to reinitiation of octreotide in those five patients who resumed treatment. Only one of the three patients with concurrent cryptosporidial infection responded to treatment. The drug was well tolerated, with mild symptomatology in three patients. Long-term treatment at a stable dose was effective in three of five treated patients for periods for seven months in one (moderate responder) and one year in two. One patient required dose increases to control symptoms, but after one year of treatment developed severe nausea following injections, which required dose cessation. One patient had partial control of his diarrhea for only three months despite two dose increases. These data suggest that octreotide may be of useful therapeutic value in HIV-associated diarrhea and that further studies are indicated.This study was supported by Sandoz Canada Inc.  相似文献   
93.
94.
95.
BACKGROUND: Capsule enteroscopy is a non-invasive diagnostic tool for the study of the small bowel. Due to the risk of capsule retention, capsule enteroscopy is contraindicated in patients with suspected small bowel strictures. The Given Patency Capsule is a disintegration time-controlled capsule developed to identify patients with strictures that may cause capsule enteroscopy retention. The presence of the patency capsule within the patient's body can be detected by a radio-frequency scanner. AIM OF THE STUDY: To evaluate safety and usefulness of the patency capsule in preventing capsule retention in patients at high risk. PATIENTS AND METHODS: Thirty-two patients were studied. Indications for patency capsule were: (A) Crohn's disease (18), (B) previous intestinal surgery (7), (C) previous obstruction (1), A+B (3), A+C (1), B+C (2). Patients were evaluated with the scanner at 72 h from ingestion. RESULTS: At 72 h, 24 patients had already excreted the intact capsule in the stool. Of these, two experienced abdominal pain during capsule passage. In the other eight patients, the scanner detected the presence of the patency capsule. Four of them excreted the capsule intact in the stool after 72-96 h, the remaining four never found the capsule in the stool. The 26 patients who excreted the patency capsule intact without experiencing abdominal pain were deemed eligible for the capsule enteroscopy procedure, which was performed uneventfully in the 25 who agreed to undergo the examination. CONCLUSIONS: The patency capsule is useful to identify, among patients at high risk, those who can be submitted to capsule enteroscopy without risks of capsule retention.  相似文献   
96.
ObjectiveThis meta-evaluation aimed to summarize all available evidence regarding different fissure sealants on occlusal caries prevention, arrest, retention rate, adverse effect, and cost-effectiveness; when compared with no intervention, other preventive or minimally-invasive procedures.Materials and MethodsThe systematic reviews and meta-analyses were identified via four electronic databases and manual searching. Two independent reviewers performed study selection, data extraction, quality assessment with AMSTAR-2.ResultsAmong the 366 records yielded, 38 systematic reviews were identified as eligible 24 of them included meta-analyses. Moderate evidence has supported the efficacies of resin-based sealants (RBS) in occlusal caries prevention, arrest and cost-effectiveness compared to no interventions. Low to very low certainty of evidence suggested similar effectiveness of glass-ionomer cements in caries prevention with RBS and more superior performance of resin infiltration in arresting non-cavitated occlusal lesions.ConclusionThis meta-evaluation supports the use of RBS on permanent molars to reduce occlusal caries occurrence, arrest lesion progression and alleviate oral health inequalities between individuals of different socioeconomic status. This meta-evaluation also advocates further research on glass-ionomer cements and resin infiltration with respect to their efficacies in caries prevention and arrest.  相似文献   
97.
98.
最近,美国哈佛大学医学部和麻省理工大学精神科学者发表文章强调抑郁症在心脏病患者中的发病率较高,约有20%~40%的心脏病人有严重抑郁障碍症状或经历抑郁性的症状。抑郁症状缓慢而持久,  相似文献   
99.
In the last 25 years there have been enormous advances in brain imaging. In addition to utility in diagnosis, these have led to novel insights into the pathogenesis of basal ganglia disease and the role of dopamine and the basal ganglia in normal health. The authors review highlights of this work, with a focus on advances in Parkinson's disease, the dystonias, Huntington's disease, and the role of dopamine in cognition and reward signaling. Emerging areas for future development include studies of functional connectivity, the analysis of default mode networks, studies of novel neurochemical pathways, methods to study disease pathogenesis, and the application of imaging techniques to investigate animal models of disease. © 2011 Movement Disorder Society  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