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   3405885篇
  免费   252065篇
  国内免费   8996篇
耳鼻咽喉   45992篇
儿科学   110780篇
妇产科学   92274篇
基础医学   478627篇
口腔科学   95183篇
临床医学   312915篇
内科学   669730篇
皮肤病学   77998篇
神经病学   282095篇
特种医学   132907篇
外国民族医学   952篇
外科学   509704篇
综合类   73031篇
现状与发展   5篇
一般理论   1302篇
预防医学   267553篇
眼科学   75339篇
药学   249061篇
  11篇
中国医学   6685篇
肿瘤学   184802篇
  2019年   27082篇
  2018年   37926篇
  2017年   29145篇
  2016年   33554篇
  2015年   37849篇
  2014年   52293篇
  2013年   78653篇
  2012年   104533篇
  2011年   110775篇
  2010年   66749篇
  2009年   63836篇
  2008年   103177篇
  2007年   109696篇
  2006年   111303篇
  2005年   107116篇
  2004年   103046篇
  2003年   99389篇
  2002年   95637篇
  2001年   162322篇
  2000年   166662篇
  1999年   140305篇
  1998年   40792篇
  1997年   36235篇
  1996年   36624篇
  1995年   35555篇
  1994年   32823篇
  1993年   30664篇
  1992年   110464篇
  1991年   106660篇
  1990年   103285篇
  1989年   99426篇
  1988年   91355篇
  1987年   89739篇
  1986年   84447篇
  1985年   80694篇
  1984年   60488篇
  1983年   51181篇
  1982年   30449篇
  1981年   27266篇
  1979年   53928篇
  1978年   38328篇
  1977年   32366篇
  1976年   30053篇
  1975年   32073篇
  1974年   38048篇
  1973年   36294篇
  1972年   33884篇
  1971年   31451篇
  1970年   28924篇
  1969年   27526篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.

Background

Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.

Methods

PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.

Results

Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P < .0001). Similarly, aortic cross-clamp time was longer in patients undergoing MIS (WMD, 0.632; 95% CI, 0.509-0.755; P < .0001). No differences were found in operative mortality, reoperation for bleeding, surgical site infection, or hospital stay.

Conclusions

MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.
  相似文献   
12.
ABSTRACT

Objective

To investigate primary care physician clinical practice patterns, barriers, and education surrounding pediatric physical activity (PA), and to compare practice patterns by discipline.  相似文献   
13.
14.
15.
16.
17.
ABSTRACT

Communication between health professionals and patients is an intergroup phenomenon where the health professional has the most power and status. Over the past few decades, there has been a steady increase in the availability to patients of information about healthcare and specific diseases on the Internet. In this paper, we ask whether the use of Internet health information assists patients to manage their consultations with health professionals better and whether it alters the intergroup dynamic by providing a more equal status for patients. In this study 370 participants from Australia and Canada completed a survey that included a ‘willingness to communicate with health professionals’ scale. They also commented on their use and trust of Internet health information. Thematic analysis suggests that patients’ use of Internet health information serves as a broker between patients and their health provider in health consultations. We discuss the implications of these findings for health practitioners as they address how easier Internet access influences patient interactions with health professionals. We consider future research directions these finding provide in explaining communication behaviour in this context.  相似文献   
18.
随着婴儿潮、人口老龄化及新技术的广泛应用,人们对听力保健的需求显著增加。在美国,听力保健服务由助听设备专员、耳鼻喉科医生和听力师3类人员提供,其中听力师提供除医疗、手术外宽泛的听力保健服务。美国的听力保健服务体系及听力师教育体系经历了一个渐进的过程:20年前对从业人员的学历要求是听力学硕士,随着对服务质量要求的提高和服务范围的扩大,美国听力师逐渐要求专业博士学位(Au.D),毕业后还需3~4年的专门教育才能成为一名听力师。听力师教育有统一的标准,大学课程要通过听力教育认证委员会(the Accreditation Commission for Audiology Education, ACAE)或学术认证委员会(the Council on Academic Accreditation,CAA)的多程序严格的认证才能被承认。美国听力师需求存在巨大缺口,但是各国听力学教育标准不统一及听力师收入与教育投资不匹配,阻碍了更多的人进入这一领域。美国试图通过改变教育模式,降低教育成本及革新教学方法等改善听力师教育状况,但是听力师教育体系远未完善。  相似文献   
19.
20.

Aims

To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.

Materials and methods

The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.

Results

In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).

Conclusions

We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis.  相似文献   
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