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   1830427篇
  免费   143729篇
  国内免费   2937篇
耳鼻咽喉   25864篇
儿科学   61271篇
妇产科学   52099篇
基础医学   261333篇
口腔科学   54540篇
临床医学   159546篇
内科学   355374篇
皮肤病学   40641篇
神经病学   151994篇
特种医学   75426篇
外国民族医学   495篇
外科学   279902篇
综合类   41117篇
现状与发展   3篇
一般理论   608篇
预防医学   135218篇
眼科学   42623篇
药学   137661篇
  3篇
中国医学   3411篇
肿瘤学   97964篇
  2018年   19280篇
  2017年   15428篇
  2016年   17907篇
  2015年   19996篇
  2014年   25875篇
  2013年   39723篇
  2012年   54421篇
  2011年   56877篇
  2010年   33255篇
  2009年   30405篇
  2008年   54935篇
  2007年   58223篇
  2006年   58894篇
  2005年   57734篇
  2004年   56374篇
  2003年   54318篇
  2002年   53218篇
  2001年   83174篇
  2000年   86823篇
  1999年   72440篇
  1998年   19823篇
  1997年   18011篇
  1996年   17674篇
  1995年   17141篇
  1994年   16148篇
  1993年   15225篇
  1992年   57576篇
  1991年   55810篇
  1990年   54527篇
  1989年   52665篇
  1988年   48819篇
  1987年   48250篇
  1986年   45804篇
  1985年   44456篇
  1984年   33430篇
  1983年   28696篇
  1982年   17080篇
  1981年   15301篇
  1979年   31775篇
  1978年   22165篇
  1977年   18741篇
  1976年   17551篇
  1975年   18690篇
  1974年   22653篇
  1973年   21648篇
  1972年   19887篇
  1971年   18759篇
  1970年   17182篇
  1969年   16090篇
  1968年   14781篇
排序方式: 共有10000条查询结果,搜索用时 2 毫秒
101.
102.
103.
The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited.  相似文献   
104.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
105.
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   
106.
BackgroundThe aim of this paper is to assess the current state of quality and outcomes measures being reported for hepatic resections in the recent literature.MethodsMedline and PubMed databases were searched for English language articles published between 1 January 2002 and 30 April 2013. Two examiners reviewed each article and relevant citations for appropriateness of inclusion, which excluded papers of liver donor hepatic resections, repeat hepatectomies or meta-analyses. Data were extracted and summarized by two examiners for analysis.ResultsFifty-five studies were identified with suitable reporting to assess peri-operative mortality in hepatic resections. In only 35% (19/55) of the studies was the follow-up time explicitly stated, and in 47% (26/55) of studies peri-operative mortality was limited to in-hospital or 30 days. The time period in which complications were captured was not explicitly stated in 19 out of 28 studies. The remaining studies only captured complications within 30 days of the index operation (8/28). There was a paucity of quality literature addressing truly patient-centred outcomes.ConclusionQuality outcomes after a hepatic resection are inconsistently reported in the literature. Quality outcome studies for a hepatectomy should report mortality and morbidity at a minimum of 90 days after surgery.  相似文献   
107.
108.
109.
110.
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