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   3504160篇
  免费   284793篇
  国内免费   15968篇
耳鼻咽喉   47314篇
儿科学   111755篇
妇产科学   91216篇
基础医学   557020篇
口腔科学   94033篇
临床医学   322526篇
内科学   615882篇
皮肤病学   90878篇
神经病学   301034篇
特种医学   135189篇
外国民族医学   392篇
外科学   529164篇
综合类   106362篇
现状与发展   23篇
一般理论   2290篇
预防医学   303238篇
眼科学   79318篇
药学   240270篇
  27篇
中国医学   10481篇
肿瘤学   166509篇
  2021年   55486篇
  2020年   35337篇
  2019年   58367篇
  2018年   72089篇
  2017年   54960篇
  2016年   60538篇
  2015年   74557篇
  2014年   108867篇
  2013年   174431篇
  2012年   99214篇
  2011年   100373篇
  2010年   119016篇
  2009年   122431篇
  2008年   86111篇
  2007年   89412篇
  2006年   99735篇
  2005年   94841篇
  2004年   96052篇
  2003年   86354篇
  2002年   75997篇
  2001年   107428篇
  2000年   100772篇
  1999年   99485篇
  1998年   65689篇
  1997年   63532篇
  1996年   61218篇
  1995年   56832篇
  1994年   50996篇
  1993年   47579篇
  1992年   70763篇
  1991年   67875篇
  1990年   64428篇
  1989年   62819篇
  1988年   58400篇
  1987年   57004篇
  1986年   54408篇
  1985年   54272篇
  1984年   49246篇
  1983年   44871篇
  1982年   42006篇
  1981年   39586篇
  1980年   37222篇
  1979年   40757篇
  1978年   35913篇
  1977年   32460篇
  1976年   30302篇
  1975年   28542篇
  1974年   30016篇
  1973年   28910篇
  1972年   27057篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
182.

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   
183.
BackgroundThe measurement of health-related quality of life (HRQoL) provides information about the perceived burden of the health condition and treatments from a lived experience. The Brisbane Burn Scar Impact Profile (caregiver report for young children, BBSIP0–8), developed in 2013, is a proxy-report measure of burn scar-specific HRQoL. The aim of this study was to report its psychometric properties in line with an evaluative purpose.MethodsCaregivers of children up to 8 years of age at risk of burn scarring were recruited into a prospective, longitudinal cohort study. Caregivers completed the BBSIP0–8, Pediatric Quality of Life Inventory and Patient Observer Scar Assessment Scale at baseline (approximately ≥85% of the total body surface area re-epithelialised), 1–2 weeks after baseline and 1-month after baseline. Psychometric properties measured included internal consistency, test–retest reliability, validity and responsiveness.ResultsEighty-six caregivers of mostly male children (55%), of a median age (IQR) of 1 year, 10 months (2 years, 1 month) and total body surface area burn of 1.5% (3.0%) were recruited. Over one third of participants were grafted and 15% had contractures or skin tightness at baseline. Internal consistency of ten item groups ranged from 0.73 to 0.96. Hypothesised correlations of changes in the BBSIP0–8 items with changes in criterion measures supported longitudinal validity (ρ ranging from ?0.73 to 0.68). The majority of item groups had acceptable reproducibility (ICC = 0.65–0.83). The responsiveness of five item groups was supported (AUC = 0.71–0.90).ConclusionThe psychometric properties tested support the use of the BBSIP0–8 as an evaluative measure of burn scar-related health-related quality of life for children aged below eight years in the early post-acute period of rehabilitation. Further investigation at longer time period after burn injury is indicated.  相似文献   
184.
185.
186.
187.
188.
The aim of this study is to review the literature to find out the exact etiology of anastomotic cancers of colon post resection and differentiate them between a recurrence, second primary, and metastatic disease (local manifestation of systemic disease). Web-based literature search was done, and datas collected. We searched PubMed for papers using the keywords colon cancer recurrence, anastomotic recurrence, and recurrent colon carcinoma. We also searched for systematic review in the same topic. In addition, we used our personal referrence archive. Anastomotic recurrences of colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. Some tumors are unique with repeated recurrence after repeated resection. Duration after primary surgery plays a major role in differentiating recurrent and second primary lesions. Repeated recurrences after repeated resections have to be considered a manifestation of systemic disease or metastatic disease due to the virulence of the disease. A detailed analysis and study of patients with colonic anastomotic lesion are required to differentiate it between a recurrent, a second primary lesion, and a metastatic disease (local manifestation of a systemic disease). The nomenclature is significant to study the survival of these patients, as a second primary lesion will have different survival compared to that of recurrent lesions.  相似文献   
189.
190.
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