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   4029599篇
  免费   330027篇
  国内免费   16460篇
耳鼻咽喉   55712篇
儿科学   126711篇
妇产科学   106934篇
基础医学   623285篇
口腔科学   110410篇
临床医学   363502篇
内科学   722609篇
皮肤病学   101646篇
神经病学   342540篇
特种医学   158450篇
外国民族医学   664篇
外科学   615139篇
综合类   126537篇
现状与发展   27篇
一般理论   2496篇
预防医学   337340篇
眼科学   93643篇
药学   281468篇
  41篇
中国医学   12438篇
肿瘤学   194494篇
  2021年   56582篇
  2020年   36164篇
  2019年   59037篇
  2018年   73392篇
  2017年   56297篇
  2016年   62248篇
  2015年   75932篇
  2014年   110452篇
  2013年   175566篇
  2012年   113885篇
  2011年   116261篇
  2010年   122355篇
  2009年   125436篇
  2008年   102057篇
  2007年   107911篇
  2006年   117400篇
  2005年   112566篇
  2004年   113565篇
  2003年   103742篇
  2002年   92822篇
  2001年   139314篇
  2000年   133998篇
  1999年   125757篇
  1998年   69545篇
  1997年   66296篇
  1996年   64094篇
  1995年   59564篇
  1994年   53636篇
  1993年   49888篇
  1992年   90490篇
  1991年   86176篇
  1990年   82047篇
  1989年   80057篇
  1988年   74299篇
  1987年   72685篇
  1986年   68770篇
  1985年   67901篇
  1984年   59209篇
  1983年   53043篇
  1982年   45725篇
  1981年   42652篇
  1980年   40155篇
  1979年   51268篇
  1978年   42725篇
  1977年   38042篇
  1976年   35012篇
  1975年   34169篇
  1974年   37456篇
  1973年   36197篇
  1972年   34085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.
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