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   2930185篇
  免费   257266篇
  国内免费   39156篇
耳鼻咽喉   37991篇
儿科学   85052篇
妇产科学   69297篇
基础医学   472119篇
口腔科学   73880篇
临床医学   279185篇
内科学   480318篇
皮肤病学   79662篇
神经病学   244107篇
特种医学   113428篇
外国民族医学   252篇
外科学   437138篇
综合类   152040篇
现状与发展   107篇
一般理论   2047篇
预防医学   246277篇
眼科学   68130篇
药学   212487篇
  453篇
中国医学   32174篇
肿瘤学   140463篇
  2022年   36201篇
  2021年   70979篇
  2020年   48044篇
  2019年   67803篇
  2018年   79374篇
  2017年   62824篇
  2016年   67002篇
  2015年   87500篇
  2014年   125243篇
  2013年   188032篇
  2012年   95421篇
  2011年   94601篇
  2010年   129114篇
  2009年   131718篇
  2008年   71860篇
  2007年   70751篇
  2006年   81878篇
  2005年   76811篇
  2004年   72558篇
  2003年   63292篇
  2002年   51633篇
  2001年   65097篇
  2000年   56466篇
  1999年   65463篇
  1998年   64703篇
  1997年   63456篇
  1996年   59969篇
  1995年   55422篇
  1994年   49180篇
  1993年   45504篇
  1992年   39827篇
  1991年   37293篇
  1990年   34280篇
  1989年   34553篇
  1988年   32292篇
  1987年   31364篇
  1986年   29713篇
  1985年   30863篇
  1984年   32730篇
  1983年   31378篇
  1982年   36314篇
  1981年   34733篇
  1980年   32790篇
  1979年   24776篇
  1978年   25418篇
  1977年   24353篇
  1976年   22011篇
  1975年   19831篇
  1974年   18537篇
  1973年   17841篇
排序方式: 共有10000条查询结果,搜索用时 10 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.
目的探讨指压天枢穴加腹部按摩联合番泻叶在静脉肾盂造影患者中的应用效果。方法选取我院2018年12月至2019年8月期间行静脉肾盂造影的120例患者,随机分为两组各60例。对照组给予番泻叶,观察组给予天枢穴指压加腹部按摩联合番泻叶,比较两组的肠道清洁力度和不良反应情况。结果治疗后,观察组的肠道清洁力度明显高于对照组(P <0.05);观察组的不良反应发生率为6.67%,明显低于对照组的23.33%(P <0.05)。结论静脉肾盂造影患者采用指压天枢穴加腹部按摩联合番泻叶的效果较好,可提高肠道清洁力度,降低不良反应发生率。  相似文献   
16.
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   
17.
18.
19.
20.

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   
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