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   3502466篇
  免费   286020篇
  国内免费   15968篇
耳鼻咽喉   47327篇
儿科学   111673篇
妇产科学   91202篇
基础医学   557007篇
口腔科学   93999篇
临床医学   322510篇
内科学   615837篇
皮肤病学   90865篇
神经病学   301035篇
特种医学   135172篇
外国民族医学   392篇
外科学   529139篇
综合类   106339篇
现状与发展   23篇
一般理论   2291篇
预防医学   303087篇
眼科学   79298篇
药学   240248篇
  27篇
中国医学   10471篇
肿瘤学   166512篇
  2021年   55513篇
  2020年   35328篇
  2019年   58363篇
  2018年   72077篇
  2017年   54958篇
  2016年   60520篇
  2015年   74543篇
  2014年   108837篇
  2013年   174407篇
  2012年   99188篇
  2011年   100353篇
  2010年   119001篇
  2009年   122426篇
  2008年   86076篇
  2007年   89380篇
  2006年   99720篇
  2005年   94821篇
  2004年   96013篇
  2003年   86314篇
  2002年   75978篇
  2001年   107412篇
  2000年   100754篇
  1999年   99479篇
  1998年   65679篇
  1997年   63528篇
  1996年   61220篇
  1995年   56829篇
  1994年   50987篇
  1993年   47575篇
  1992年   70754篇
  1991年   67869篇
  1990年   64419篇
  1989年   62806篇
  1988年   58395篇
  1987年   56996篇
  1986年   54401篇
  1985年   54269篇
  1984年   49247篇
  1983年   44872篇
  1982年   42010篇
  1981年   39587篇
  1980年   37224篇
  1979年   40758篇
  1978年   35916篇
  1977年   32462篇
  1976年   30302篇
  1975年   28543篇
  1974年   30015篇
  1973年   28911篇
  1972年   27057篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
13.
14.
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   
15.
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   
16.
17.
18.
19.

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   
20.
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