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   2821060篇
  免费   238115篇
  国内免费   15281篇
耳鼻咽喉   38609篇
儿科学   84582篇
妇产科学   70701篇
基础医学   465142篇
口腔科学   75652篇
临床医学   248031篇
内科学   485881篇
皮肤病学   80142篇
神经病学   244436篇
特种医学   110170篇
外国民族医学   108篇
外科学   446374篇
综合类   91085篇
现状与发展   24篇
一般理论   2051篇
预防医学   229506篇
眼科学   64280篇
药学   193694篇
  23篇
中国医学   9829篇
肿瘤学   134136篇
  2022年   22877篇
  2021年   54639篇
  2020年   34871篇
  2019年   57746篇
  2018年   69571篇
  2017年   52928篇
  2016年   58348篇
  2015年   73251篇
  2014年   107327篇
  2013年   172218篇
  2012年   73512篇
  2011年   70019篇
  2010年   111132篇
  2009年   117303篇
  2008年   57442篇
  2007年   58056篇
  2006年   69807篇
  2005年   65017篇
  2004年   67244篇
  2003年   58827篇
  2002年   48843篇
  2001年   79095篇
  2000年   70677篇
  1999年   75877篇
  1998年   62740篇
  1997年   61126篇
  1996年   58194篇
  1995年   53690篇
  1994年   47772篇
  1993年   44789篇
  1992年   49512篇
  1991年   45967篇
  1990年   42825篇
  1989年   43280篇
  1988年   39997篇
  1987年   38843篇
  1986年   36644篇
  1985年   37400篇
  1984年   37011篇
  1983年   34765篇
  1982年   37604篇
  1981年   35694篇
  1980年   33690篇
  1979年   28115篇
  1978年   27427篇
  1977年   26205篇
  1976年   23282篇
  1975年   21273篇
  1974年   20202篇
  1973年   19255篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
Abstract

Objective: To understand the origin of extremely high gonadotropin levels in a perimenopausal woman.

Methods: A 52-year-old woman with a 2?months of amenorrhea followed spontaneous menstrual cycles recovery was referred to our outpatient clinic with elevated follicle-stimulating hormone (FSH, 483 mUI/ml), luteinizing hormone (LH, 475 mUI/ml) and prolactin (PRL, 173?ng/ml). She was known to take levosulpiride. The gonadotropin levels did not fit with the clinical features.

Results: A gonadotroph tumor was ruled out. Further analysis confirmed constantly high FSH, LH and PRL levels. The measurements were repeated using different analytical platforms with different results. After serial dilutions, nonlinearity was present suggesting an immunoassay interference. After post-polyethylene glycol recovery, hormone levels appeared in the normal range. Anti-goat antibodies were recognized in the serum of the patient.

Conclusions: This case report shows a case of falsely abnormal high gonadotropin and PRL levels in a woman during menopause transition. In the clinical practice the evaluation of gonadotropin profile is not recommended at this age, but the abnormal levels stimulated further evaluation. An interference in the assay due to anti-goat antibodies resulted in abnormally high level of FSH and LH. A strict collaboration between clinicians and the laboratory is needed, when laboratory findings do not correspond to clinical findings.  相似文献   
14.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.  相似文献   
15.
16.
17.
18.

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   
19.
20.
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   
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