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   3315048篇
  免费   269559篇
  国内免费   13542篇
耳鼻咽喉   44998篇
儿科学   102663篇
妇产科学   84055篇
基础医学   529744篇
口腔科学   89260篇
临床医学   298149篇
内科学   577199篇
皮肤病学   90694篇
神经病学   281281篇
特种医学   131414篇
外国民族医学   225篇
外科学   513091篇
综合类   100271篇
现状与发展   25篇
一般理论   2188篇
预防医学   273658篇
眼科学   76136篇
药学   232679篇
  27篇
中国医学   9969篇
肿瘤学   160423篇
  2021年   55071篇
  2020年   35218篇
  2019年   57956篇
  2018年   70988篇
  2017年   54151篇
  2016年   59875篇
  2015年   74120篇
  2014年   108362篇
  2013年   173505篇
  2012年   88245篇
  2011年   87426篇
  2010年   115764篇
  2009年   120552篇
  2008年   74338篇
  2007年   76784篇
  2006年   87889篇
  2005年   82885篇
  2004年   84698篇
  2003年   75775篇
  2002年   65467篇
  2001年   107105篇
  2000年   99919篇
  1999年   98863篇
  1998年   65098篇
  1997年   62920篇
  1996年   60670篇
  1995年   56214篇
  1994年   50114篇
  1993年   46857篇
  1992年   68050篇
  1991年   64380篇
  1990年   61425篇
  1989年   60552篇
  1988年   55541篇
  1987年   54032篇
  1986年   51215篇
  1985年   50948篇
  1984年   46676篇
  1983年   42695篇
  1982年   40796篇
  1981年   38387篇
  1980年   36325篇
  1979年   37672篇
  1978年   33370篇
  1977年   31360篇
  1976年   28154篇
  1975年   27042篇
  1974年   27215篇
  1973年   26179篇
  1972年   24576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