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   3730332篇
  免费   311871篇
  国内免费   13819篇
耳鼻咽喉   51128篇
儿科学   119070篇
妇产科学   97551篇
基础医学   583358篇
口腔科学   103041篇
临床医学   333662篇
内科学   665732篇
皮肤病学   95559篇
神经病学   318936篇
特种医学   149366篇
外国民族医学   497篇
外科学   575555篇
综合类   113967篇
现状与发展   23篇
一般理论   2429篇
预防医学   311268篇
眼科学   86407篇
药学   260911篇
  22篇
中国医学   10154篇
肿瘤学   177386篇
  2021年   55444篇
  2020年   35285篇
  2019年   58261篇
  2018年   71885篇
  2017年   54793篇
  2016年   60633篇
  2015年   74524篇
  2014年   108900篇
  2013年   174036篇
  2012年   99576篇
  2011年   100073篇
  2010年   118470篇
  2009年   122604篇
  2008年   87376篇
  2007年   90766篇
  2006年   101560篇
  2005年   96561篇
  2004年   99127篇
  2003年   89313篇
  2002年   79129篇
  2001年   120895篇
  2000年   115181篇
  1999年   111753篇
  1998年   67073篇
  1997年   64618篇
  1996年   62613篇
  1995年   58225篇
  1994年   52374篇
  1993年   48909篇
  1992年   82948篇
  1991年   79417篇
  1990年   75960篇
  1989年   74631篇
  1988年   69458篇
  1987年   68150篇
  1986年   64949篇
  1985年   64818篇
  1984年   56592篇
  1983年   51297篇
  1982年   44777篇
  1981年   41923篇
  1980年   39527篇
  1979年   48968篇
  1978年   40966篇
  1977年   36781篇
  1976年   34082篇
  1975年   32841篇
  1974年   35537篇
  1973年   34198篇
  1972年   31691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.

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