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   3455279篇
  免费   287716篇
  国内免费   13629篇
耳鼻咽喉   48428篇
儿科学   112034篇
妇产科学   89318篇
基础医学   547138篇
口腔科学   90921篇
临床医学   307752篇
内科学   617537篇
皮肤病学   91226篇
神经病学   294122篇
特种医学   137373篇
外国民族医学   686篇
外科学   536623篇
综合类   102723篇
现状与发展   23篇
一般理论   2273篇
预防医学   289309篇
眼科学   78894篇
药学   237914篇
  23篇
中国医学   9655篇
肿瘤学   162652篇
  2021年   55021篇
  2020年   35055篇
  2019年   58104篇
  2018年   71227篇
  2017年   54279篇
  2016年   59855篇
  2015年   74000篇
  2014年   108161篇
  2013年   173337篇
  2012年   92148篇
  2011年   92077篇
  2010年   116665篇
  2009年   121207篇
  2008年   79974篇
  2007年   83379篇
  2006年   94002篇
  2005年   89495篇
  2004年   91640篇
  2003年   82766篇
  2002年   72927篇
  2001年   110051篇
  2000年   104111篇
  1999年   102900篇
  1998年   66079篇
  1997年   63497篇
  1996年   61446篇
  1995年   56893篇
  1994年   51144篇
  1993年   47681篇
  1992年   72827篇
  1991年   69889篇
  1990年   66387篇
  1989年   64853篇
  1988年   60021篇
  1987年   58816篇
  1986年   55211篇
  1985年   55215篇
  1984年   49835篇
  1983年   45405篇
  1982年   41902篇
  1981年   39675篇
  1980年   37194篇
  1979年   40819篇
  1978年   35733篇
  1977年   32700篇
  1976年   30043篇
  1975年   28950篇
  1974年   29668篇
  1973年   28579篇
  1972年   26534篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
Aging alters bladder functions where a decrease in filling, storage and emptying is observed. These changes cause urinary incontinence, especially in women. The aim of this study is to examine how aging affects the intracellular calcium movements due to agonist-induced contractions in permeabilized female rat bladder. Urinary bladder isolated from young and old female Sprague-Dawley rats were used. Small detrusor strips were permeabilized with β-escin. The contractile responses induced with agonists were compared between young and old groups. Carbachol-induced contractions were decreased in permeabilized detrusor from old rats compared to young group. Heparin and ryanodine decreased carbachol-induced contractions in young rats where only heparin inhibited these contractions in olds. Caffeine-induced contractions but not inositol triphosphate (IP3)-induced contractions were decreased in old group compared to youngs. The cumulative calcium response curves (pCa 8–4) were also decreased in old rats. Carbachol-induced calcium sensitization responses did not alter by age where GTP-β-S and GF-109203X but not Y-27632 inhibited these responses. Carbachol-induced contractions decrease with aging in rat bladder detrusor. It can be postulated as IP3-induced calcium release (IICR) is primarily responsible for the contractions in older rats where the decrease in carbachol contractions in aging may be as a result of a decrease in calcium-induced calcium release (CICR), rather than carbachol-induced calcium sensitization.  相似文献   
102.
103.
There is a large and growing population of long-term cancer survivors. Primary care physicians (PCPs) are playing an increasingly greater role in the care of these patients across the continuum of cancer survivorship. In this role, PCPs are faced with the responsibility of managing a range of medical and psychosocial late effects of cancer treatment. In particular, the sexual side effects of treatment which are common and have significant impact on quality of life for the cancer survivor, often go unaddressed. This is an area of clinical care and research that has received increasing attention, highlighted by the presentation of this special issue on Cancer and Sexual Health. The aims of this review are 3-fold. First, we seek to overview common presentations of sexual dysfunction related to major cancer diagnoses in order to give the PCP a sense of the medical issues that the survivor may present with. Barriers to communication about sexual health issues between patient/PCPs in order are also described in order to emphasize the importance of PCPs initiating this important conversation. Next, we provide strategies and resources to help guide the PCP in the management of sexual dysfunction in cancer survivors. Finally, we discuss case examples of survivorship sexual health issues and highlight the role that a PCP can play in each of these case examples.  相似文献   
104.
105.
106.
107.
108.
109.
110.

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