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   701篇
  免费   42篇
  国内免费   34篇
儿科学   44篇
妇产科学   9篇
基础医学   72篇
口腔科学   27篇
临床医学   102篇
内科学   152篇
皮肤病学   17篇
神经病学   10篇
特种医学   115篇
外科学   61篇
综合类   15篇
预防医学   31篇
眼科学   2篇
药学   78篇
肿瘤学   42篇
  2022年   2篇
  2021年   6篇
  2020年   6篇
  2019年   3篇
  2018年   11篇
  2017年   6篇
  2016年   8篇
  2015年   11篇
  2014年   25篇
  2013年   28篇
  2012年   15篇
  2011年   12篇
  2010年   27篇
  2009年   36篇
  2008年   12篇
  2007年   29篇
  2006年   16篇
  2005年   13篇
  2004年   11篇
  2003年   12篇
  2002年   14篇
  2001年   8篇
  2000年   19篇
  1999年   24篇
  1998年   35篇
  1997年   34篇
  1996年   38篇
  1995年   28篇
  1994年   35篇
  1993年   21篇
  1992年   10篇
  1991年   9篇
  1990年   10篇
  1989年   27篇
  1988年   32篇
  1987年   15篇
  1986年   15篇
  1985年   13篇
  1984年   10篇
  1983年   8篇
  1982年   13篇
  1981年   14篇
  1980年   15篇
  1979年   3篇
  1978年   7篇
  1977年   3篇
  1976年   9篇
  1975年   9篇
  1973年   3篇
  1972年   2篇
排序方式: 共有777条查询结果,搜索用时 15 毫秒
761.
762.
Four months into a year‐long, national survey assessing parents' experiences of a child's diagnosis of autism spectrum disorder, our response fraction was only 23%. We aimed to determine whether including a chocolate incentive in the postal survey would increase the response fraction. Families enrolled between 15 March and 25 May 2012 were randomised to receive a chocolate frog versus no chocolate frog. Both groups received a written reminder and replacement survey 2 weeks after the survey was posted and up to two telephone reminders thereafter. We analysed the effect of the incentive using χ2 tests for the categorical response variable and t‐tests for the continuous reminder and length of response variables at the end of (i) randomisation and (ii) the study (1 November 2012). A total of 137 families were randomised in the 6‐week period. Parents who received an incentive were more likely to return a completed survey in the 6 weeks than those who did not (21% vs. 6%, P = 0.009). This effect faded by the end of the study (53% vs. 42%, P = 0.4). There were no differences between groups at either follow‐up in the number of reminders that parents received or the number of days it took parents to return the survey. Including a chocolate‐based incentive does not significantly increase response rate in a postal survey over and above standard reminder techniques like posting follow‐up survey packs or phoning families.  相似文献   
763.
OBJECTIVES: Renal transplant recipients (RTR) represent a large and growing population of individuals on potent immunosuppressant therapy who are at significantly greater risk of developing lip and oral mucosal disease, including lip cancer. The aims of this study were to determine the proportion of RTR receiving regular dental treatment, the dental services they used, and the relationship between the prevalence of lip and intraoral lesions and dental attendance.
DESIGN: The lip and oral mucosa of 159 RTR and 160 controls were examined. Subjects were asked questions about frequency of dental attendance and which service they used.
RESULTS: 57.9% RTR attended a dentist regularly compared with 51.3% controls. Among the RTR who attended a dentist regularly, 54.3% visited their general dental practitioner, and 45.6% attended a dental hospital for treatment. This was significantly different from controls where 92.7% of regular attenders used their general dental practitioner (P<0.001). Although the prevalence of oral lesions in RTR (54.7%) was more than twice as many as controls (19.4%). no significant difference was observed between RTR regular dental attenders and non-attenders.
CONCLUSIONS: This study indicates a clear need for oral health care and screening to be focused on RTR.  相似文献   
764.
765.
Severe infections with multiresistant bacteria (MRB) are a medical challenge and a financial burden for hospitals. The adequate antibiotic therapy is a key issue in multiresistant bacteria management. Several major cost drivers have been identified. Remarkably drug acquisition costs are not necessarily included. Most significant are the length of stay in hospital, the hours of mechanical ventilation and the time treated on an intensive care unit.In a systematic review of the literature the following aspects were investigated:- Do generic treatment strategies contribute in cost savings?- Are there specific results for recent antibiotics?Early adequate and effective antimicrobial treatment, switch from i.v. to oral therapy, adjusted duration of therapy and adherence to guidelines have been found to be successful strategies.Looking at specific antibiotics, the best evidence for cost-effectiveness is found for Linezolid in treatment of cSSTI as well as in HAP. Daptomycin shows good economic results in bloodstream infections, so possibly being a cost-effective alternative to vancomycin. Looking at tigecycline the published data show neither higher costs nor savings compared to imipeneme. Doripenem as one of the newest therapy options has proven to be highly cost-saving in HAP when compared with imipenem. However, most analyses are based on pharmacoeconomic modelling rather than on directly analysing trial data or real life clinical populations.

Conclusion

Using modern antibiotics in whole is not more expensive than using established therapies. Modern antibiotics are cost-effective and sometimes even cost-saving. This is especially true if an effective therapy is initiated as early as possible.  相似文献   
766.

Background  

It is known that when barefoot, gait biomechanics of diabetic neuropathic patients differ from non-diabetic individuals. However, it is still unknown whether these biomechanical changes are also present during shod gait which is clinically advised for these patients. This study investigated the effect of the participants own shoes on gait biomechanics in diabetic neuropathic individuals compared to barefoot gait patterns and healthy controls.  相似文献   
767.

INTRODUCTION

It has been suggested that changes to the training schemes of junior doctors and the increased pressure on emergency departments to manage their patients within a limited time might increase the number of unnecessary investigations performed on emergency admission patients. This, in turn, may lead to an increased number of investigations with normal results. In this study we try to analyse the role of the chest X-ray (CXR) as a diagnostic tool in patients presenting with acute abdominal pain.

PATIENTS AND METHODS

A retrospective study was performed of the request forms and results of all chest radiography performed on patients admitted on the emergency surgical intake with acute abdominal pain through utilisation of the prospec-tively maintained electronic radiology database. The indications were compared to the guidelines published by the Royal College of Radiologists (RCR) which have been adopted as the standard of care.

RESULTS

A total of 334 chest X-rays were identified of which only 23 (7%) had new findings. Four (1%) patients had free gas under the diaphragm. Of the CXRs, 258 (77%) were reported normal whilst 53 (16%) had old changes which were described in their hospital records and previous radiographs. Of the CXRs with new findings, only 20 were clinically significant and, of these, four (1%) were surgically significant.

CONCLUSIONS

The majority of CXRs performed on emergency surgical admissions with abdominal pain are unnecessary. By obtaining a clear history, performing a thorough clinical examination and following the RCR guidelines most of the CXRs could be avoided. This would lead to less radiation exposure, reduce delays to diagnosis, and provide significant financial savings.  相似文献   
768.
769.
NADPH-cytochrome P450 reductase (CPR) and cytochrome-b(5) (b(5)) together with NADH-b(5) reductase (b(5)R) play important roles in cytochrome P450 3A-mediated drug metabolism via electron transfer. However, it is not clear whether variability in expression of these accessory proteins contributes to the known interindividual variability in CYP3A activity. CPR and b(5) were measured in human liver microsomes (HLMs) by spectrophotometry and immunoblotting. HLMs from elderly (>or=46 years) male donors (n=11) averaged 27% (P=0.034) and 41% (P=0.011) lower CPR levels than young (相似文献   
770.

Introduction  

Patients after out-of-hospital cardiac arrest (OHCA) benefit from therapeutic hypothermia for 24 hours. The time needed to reach hypothermia (target temperature of 32°C to 34°C) varies widely. In this study, we explore the relation between measures of body composition and the time needed to reach target temperature with hypothermia.  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