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   90140篇
  免费   6968篇
  国内免费   778篇
耳鼻咽喉   1235篇
儿科学   1991篇
妇产科学   1999篇
基础医学   13196篇
口腔科学   1505篇
临床医学   8742篇
内科学   18238篇
皮肤病学   2545篇
神经病学   7122篇
特种医学   4211篇
外科学   11431篇
综合类   1696篇
现状与发展   1篇
一般理论   48篇
预防医学   5374篇
眼科学   2917篇
药学   7606篇
中国医学   829篇
肿瘤学   7200篇
  2023年   584篇
  2022年   1415篇
  2021年   2456篇
  2020年   1412篇
  2019年   1983篇
  2018年   2402篇
  2017年   1849篇
  2016年   2485篇
  2015年   3157篇
  2014年   3810篇
  2013年   4547篇
  2012年   6604篇
  2011年   6528篇
  2010年   3866篇
  2009年   3267篇
  2008年   4824篇
  2007年   4797篇
  2006年   4557篇
  2005年   4378篇
  2004年   3823篇
  2003年   3418篇
  2002年   3077篇
  2001年   2176篇
  2000年   2075篇
  1999年   1770篇
  1998年   745篇
  1997年   626篇
  1996年   546篇
  1995年   489篇
  1994年   435篇
  1993年   451篇
  1992年   1055篇
  1991年   1077篇
  1990年   958篇
  1989年   983篇
  1988年   938篇
  1987年   944篇
  1986年   818篇
  1985年   767篇
  1984年   595篇
  1983年   471篇
  1982年   335篇
  1981年   308篇
  1980年   288篇
  1979年   436篇
  1978年   345篇
  1977年   253篇
  1974年   263篇
  1973年   282篇
  1972年   244篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
25.
Background

There is an increasing incidence of elderly patients requiring emergency laparotomy. Our study compares the outcomes of elderly patients undergoing emergency laparotomy against the outcomes of non-elderly patients.

Methodology

Patients who underwent emergency laparotomy between 2015 and 2017 from the National University Hospital, Singapore, were included. Apart from demographic data, indication of surgery and surgical procedure performed were collected. Prospectively collected nutritional scores were evaluated. Outcome measures included duration of surgery, length of ICU and total hospital stay, post-operative complications, and mortality indices. We performed multivariate Cox regression analysis to determine the contribution of various risk factors towards overall survival following emergency laparotomy.

Results

A total of 170 emergency laparotomies were performed. Compared to non-elderly patients, elderly patients had a significantly longer mean stay in hospital (31.5 vs. 18.6 days, p = 0.006) and mean stay in ICU (13.1 vs. 5.3 days, p = 0.003). More elderly patients suffered from post-laparotomy complications compared with non-elderly patients (65.8% vs. 37.4%, p < 0.001). 30-day mortality (31.5% vs. 8.8%, p = 0.019) and 1-year mortality (27.9% vs. 14.3%, p = 0.023) were higher in elderly patients compared with non-elderly patients. Interestingly, there was no statistically significant difference between elderly and non-elderly groups in both the global 3-MinNS as well as the global SGA nutritional scores. ASA status (HR 2.61, 95% CI 1.05–6.45, p = 0.038) was an independent risk factor for decreased survival following emergency laparotomy. Notably, while age ≥ 65 demonstrated a significant correlation with survival on univariate analysis (HR 1.03 (1.01–1.05), p = 0.003), this effect was lost following multivariate regression (HR 1.01 (0.453–2.23), p = 0.989).

Conclusion

Elderly patients suffer worse morbidity and mortality following emergency laparotomy. This is likely contributed by comorbidities resulting in higher ASA status.

  相似文献   
26.
Approximately 36 400 cardiac and 23 100 thoracic operations are carried out in the United Kingdom between 2006 and 2015. National Health Service (NHS) resolution, as known as the NHS litigation authority, is one of the essential bodies of the Department of Health. Its purpose is to provide NHS expertise to resolve concerns fair and square share learning for improvement. We aim to evaluate and increase awareness of medicolegal cases in cardiothoracic surgery. Total numbers and details of claims coded by NHS resolution in cardiothoracic surgery from 2004 to 2017 were requested under the Freedom of Information Act 2000. The data provided in successful claims is further breakdown into damages paid to the claimant, defence cost, claimant cost paid and the sum of the three. In contrast, unsuccessful claims only include the defence cost. Moreover, data provided also includes further analysis of primary causes and primary injuries for Claims Closed/Settled with damages paid. There were 753 claims recorded from 2004 to 2017, of which 415 (55.11%) were successful. The number of claims has been steadily increasing since 2004, with two significant raises from 2009/10 to 2010/11 (37‐55, 48.64% raise) and 2012/13 to 2013/14 (49‐69, 40.82% raise). The mean successful claim ratio was 69.58% (range, 47.56%‐ 83.33%) There is also a steady increase in the successful ratio from 2004 to 2017. In summary, this is the first study published in relation to litigation claims on cardiothoracic surgery in the United Kingdom. The results have provided insight on claims made against cardiothoracic surgery.  相似文献   
27.
28.
29.
Background: Few studies have examined the use of ultrasound for sciatic nerve localization. The authors evaluated the usefulness of low-frequency ultrasound in identifying the sciatic nerve at three locations in the lower extremity and in guiding needle advancement to target before nerve stimulation.

Methods: In this prospective observational study, 15 volunteers underwent sciatic nerve examination using a curved ultrasound probe in the range of 2-5 MHz and a Philips-ATL 5000 unit (ATL Ultrasound, Bothell, WA) in the gluteal, infragluteal, and proximal thigh regions. Thereafter, an insulated block needle was advanced inline with the ultrasound beam to reach the nerve target, which was further confirmed by electrical stimulation. The quality of sciatic nerve images, ease of needle to nerve contact, threshold stimulating current, and resultant motor response were recorded.

Results: The sciatic nerve was successfully identified in the transverse view as a solitary predominantly hyperechoic structure on ultrasound in all of the three regions examined. The target nerve was visualized easily in 87% and localized within two needle attempts in all patients. Nerve stimulation was successful in 100% after two attempts with a threshold current of 0.42 +/- 0.12 (mean +/- SD) eliciting foot plantarflexion or dorsiflexion.  相似文献   

30.
Abstract: Background: Fetal pulse oximetry improves the assessment of fetal well‐being during labor. The objective of this study was to evaluate women's satisfaction with their experience with this additional technology. Methods: We surveyed women participating in the FOREMOST trial, a randomized controlled trial comparing the addition of fetal pulse oximetry (FPO) to conventional cardiotocograph (CTG) monitoring (intervention group), versus CTG‐only (control group), in the presence of nonreassuring fetal status during labor. Our survey evaluated 3 aspects of women's experience: labor, fetal monitoring, and participation in the research. The survey was administered within a few days of giving birth and repeated 3 months later. Results: No differences were found between the intervention and control groups for women's evaluations of their labor, fetal monitoring, research, or overall experiences when surveyed on both occasions. Within each study group, a small but statistically significant decline occurred in women's scores for their experience of labor and overall experience from the initial survey close to the time of giving birth, to 3 months later. The magnitude of differences in responses over time was similar for the both groups. Women were more satisfied after a spontaneous or assisted vaginal birth than after cesarean section. Length of time the research midwife was present had a significant positive effect on women's ratings of their experience several days after giving birth (p = 0.006), but no effect at 3 months. Conclusions: The addition of fetal pulse oximetry for the assessment of fetal well‐being during labor did not affect childbearing women's perceptions of fetal monitoring or their labor. Women evaluated their experience in the research process positively overall. Small changes occurred in women's perception of their satisfaction over time. (BIRTH 33:2 June 2006)  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