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   5859162篇
  免费   430433篇
  国内免费   16722篇
耳鼻咽喉   83549篇
儿科学   188747篇
妇产科学   158578篇
基础医学   858008篇
口腔科学   165671篇
临床医学   545831篇
内科学   1067325篇
皮肤病学   135993篇
神经病学   480069篇
特种医学   225181篇
外国民族医学   1515篇
外科学   873697篇
综合类   162435篇
现状与发展   25篇
一般理论   3241篇
预防医学   489995篇
眼科学   141583篇
药学   419277篇
  28篇
中国医学   15153篇
肿瘤学   290416篇
  2021年   58363篇
  2019年   60393篇
  2018年   79416篇
  2017年   61085篇
  2016年   68012篇
  2015年   79289篇
  2014年   114006篇
  2013年   180064篇
  2012年   172828篇
  2011年   186804篇
  2010年   141442篇
  2009年   137662篇
  2008年   170617篇
  2007年   184849篇
  2006年   190488篇
  2005年   184315篇
  2004年   183819篇
  2003年   172603篇
  2002年   160883篇
  2001年   236551篇
  2000年   235427篇
  1999年   207622篇
  1998年   81257篇
  1997年   74047篇
  1996年   72009篇
  1995年   67303篇
  1994年   61236篇
  1993年   56561篇
  1992年   154464篇
  1991年   149317篇
  1990年   144721篇
  1989年   140983篇
  1988年   130125篇
  1987年   127526篇
  1986年   120489篇
  1985年   117216篇
  1984年   92572篇
  1983年   80973篇
  1982年   56640篇
  1981年   52168篇
  1980年   48889篇
  1979年   83430篇
  1978年   63357篇
  1977年   54830篇
  1976年   51411篇
  1975年   53575篇
  1974年   61599篇
  1973年   59040篇
  1972年   55777篇
  1971年   52111篇
排序方式: 共有10000条查询结果,搜索用时 0 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