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   1974篇
  免费   210篇
  国内免费   4篇
耳鼻咽喉   12篇
儿科学   59篇
妇产科学   25篇
基础医学   250篇
口腔科学   20篇
临床医学   201篇
内科学   416篇
皮肤病学   8篇
神经病学   218篇
特种医学   77篇
外科学   358篇
综合类   67篇
一般理论   1篇
预防医学   179篇
眼科学   9篇
药学   106篇
肿瘤学   182篇
  2021年   21篇
  2020年   18篇
  2019年   19篇
  2018年   30篇
  2017年   25篇
  2016年   46篇
  2015年   43篇
  2014年   56篇
  2013年   91篇
  2012年   93篇
  2011年   127篇
  2010年   59篇
  2009年   57篇
  2008年   75篇
  2007年   91篇
  2006年   90篇
  2005年   64篇
  2004年   74篇
  2003年   64篇
  2002年   73篇
  2001年   77篇
  2000年   90篇
  1999年   64篇
  1998年   19篇
  1997年   26篇
  1996年   25篇
  1995年   22篇
  1994年   18篇
  1992年   33篇
  1991年   38篇
  1990年   40篇
  1989年   38篇
  1988年   31篇
  1987年   24篇
  1986年   21篇
  1985年   16篇
  1984年   20篇
  1983年   23篇
  1979年   18篇
  1978年   16篇
  1977年   21篇
  1975年   14篇
  1974年   23篇
  1973年   29篇
  1972年   17篇
  1971年   18篇
  1970年   13篇
  1969年   14篇
  1968年   13篇
  1967年   15篇
排序方式: 共有2188条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.

Background

The effect of the laparoscopic adjustable gastric band (LAGB) on the esophagus has been the subject of few studies despite recognition of its clinical importance. The aim of this study was to investigate the frequency and clinical effect of esophageal dysmotility and dilatation after LAGB.

Methods

We undertook a retrospective analysis of 50 consecutive patients with no dysmotility on perioperative video contrast swallow who underwent primary LAGB operation. All patients had serial focused postoperative contrast studies for band adjustments at least 6 months post-LAGB. Clinical and radiological outcomes were assessed.

Results

Median follow-up time was 18 months (range 7–39 months), and the median number of contrast swallows per patient was 5. The mean excess weight loss (EWL) overall was 47 % (standard deviation (SD) 22.3). Radiological abnormalities were recorded in 17 patients (34 %, 95 % confidence interval (CI) 21–49 %), of whom 15 had radiological dysmotility and 7 had esophageal dilatation (five patients had both dysmotility and dilatation). Of these 17 patients, six (35 %) developed significant symptoms of dysphagia, gastroesophageal reflux disease (GERD) or regurgitation requiring fluid removal. In comparison, 12 of 33 (36 %) patients without radiological abnormalities developed symptoms requiring fluid removal (p?=?1.00). Patients with radiological abnormalities were significantly older than those without these abnormalities. Symptoms were alleviated by removing fluid in most patients.

Conclusions

The LAGB operation results in the development of radiological esophageal dysmotility in a significant proportion of patients. It is not clear if these changes are associated with an increased risk of significant symptoms. Fluid removal can reverse these abnormalities and their associated symptoms.  相似文献   
6.
A new language measure, the Observation of Spontaneous Expressive Language (OSEL), is intended to document spontaneous use of syntax, pragmatics, and semantics in 2–12-year-old children with Autism Spectrum Disorder (ASD) and other communication disorders with expressive language levels comparable to typical 2–5 year olds. Because the purpose of the OSEL is to provide developmental norms for use of language, the first step involves assessment of the scale’s feasibility, validity, and reliability using a sample of 180 2–5 year-old typically developing children. Pilot data from the OSEL shows strong internal consistency, high reliabilities and validity. Once replicated with a large population-based sample and in special populations, the scale should be helpful in designing appropriate interventions for children with ASD and other communication disorders.  相似文献   
7.

Background

This study was designed to evaluate the outcomes of pancreaticoduodenectomy (PD) at a low-volume specialised Hepato Pancreato Biliary (HPB) unit. Volume outcome analyses show significantly better results for patients undergoing PD at high-volume centres (Begg et al. JAMA 280:1747–1751, 1998; Finlayson et al. Arch Surg 138:721–725, 2003; Birkmeyer et al. N Engl J Med 346:1128–1137, 2002; Gouma et al. Ann Surg 232:786–795, 2000). Centralisation of PD seems to be the logical conclusion to be drawn from these results. In countries like Australia with a small and widely dispersed population, centralisation may not be always feasible. Alternative strategy would be to have similar systems in place to those in high-volume centres to achieve similar results at low-volume centres. Many Australian tertiary care centres perform low to medium volumes of PD (Chen et al. HPB 12:101–108, 2010; Kwok et al. ANZ J Surg 80:605–608, 2010; Barnett and Collier ANZ J Surg 76:563–568, 2006; Samra et al. Hepatobiliary Pancreat Dis Int 10:415–421, 2011). Most of these have a specialised HPB unit, accredited by the Australia and New Zealand Hepatic pancreatic and biliary association (ANZHPBA), as training units for post fellowship training in HPB surgery. It is imperative to perform outcome-based analyses in these units to ensure safety and high quality of care.

Methods

Retrospective analysis of database for periampullary carcinoma (1998 till date) was performed in an ANZHPBA accredited HPB unit based at a tertiary care teaching hospital in South Australia. Because age older than 74 years is shown to be a predictive marker of increased morbidity and mortality after a PD, we analysed the outcomes in this subset of patients separately.

Results

Fifty-three patients underwent PD in 14 years. Overall mortality was 3.8 %. The last in hospital mortality was in 1999. The morbidity rates and the oncologic outcomes were similar to those in high-volume units.

Conclusions

PD can be safely performed in a low-volume specialised unit at centres where the amenities and processes at high-volume centres can be replicated.  相似文献   
8.

Objective

Pain relief is a key out-of-hospital patient care outcome measure, yet many trauma patients do not receive prompt analgesia. Although specialty critical care transport (CCT) teams provide analgesia frequently, successfully, and safely, there is still a population of CCT patients to whom analgesia is not offered. We report the factors associated with non-administration of analgesia and with analgesic effect in trauma patients cared for by CCT teams.

Methods

This is a retrospective review of consecutive transport records for nonintubated trauma patients with self-reported pain during specialty CCT care. Patient demographics, CCT interventions, clinical traits, and pain self-reports are measured. Means comparisons are made with a univariate analysis of variance, and odds ratios (ORs) with 95% confidence intervals (CIs) are reported for between-group comparisons.

Results

Of the 209 enrolled patients, 169 (80.9%; 95% CI, 75.6%-86.2%) were treated (147 received analgesia and 22 offered analgesia but refused). In patients with pain scale documentation (n = 145), self-reported pain on a scale from 0 to 10 decreased from 6.8 ± 2.8 to 3.3 ± 2.4 (P ≤ .001). Three factors were associated with absence of analgesic administration: initial pain level (OR for administration, 0.13; 95% CI, 0.04-0.40), pain scale documentation (OR, 0.31; 95% CI, 0.15-0.60), and transport program (OR, 0.36; 95% CI, 0.17-0.74). No clinical factor was associated with analgesia effectiveness in treated patients.

Conclusion

The identified factors may represent opportunities for CCT teams to optimize analgesic treatment.  相似文献   
9.
There is now widespread interest in developing social policies and practices that are grounded in principles of independent living. The Independent Living (IL) paradigm reflects a shift in thinking away from traditional approaches to supporting persons with disabilities. Independent Living Centres (ILCs), which started in the early 1970s in the United States, and in the 1980s in Canada, are now a major force in the promotion of the IL concept worldwide. The guiding principles of these consumer-driven centres include: promoting an empowerment philosophy that incorporates consumer control/self-direction over decision-making; offering cross-disability support; providing options/choice and flexibility; and encouraging inclusion and full participation. Despite their prevalence, a surprisingly limited body of research exists on the impact of ILCs. A survey was used to investigate the impact of ILCs in Canada on their communities of interest (groups connected to the ILCs). Surveys were sent to formal organizations, informal groups, and family/friends. A final response rate of 52.6% was achieved (111 of 211 surveys returned). Overall, moderate to good levels of familiarity, involvement, and impact were found. The results affirmed the importance of independent living centres to individual empowerment, community change, and the IL movement.  相似文献   
10.
It is not clear if low end-expiratory pressures contribute to ventilator-induced lung injury in large animals. We sought to determine whether ventilation with a low level of positive end-expiratory pressure (PEEP) worsens preexisting permeability lung injury in dogs. Lung injury was initiated in 20 mongrel dogs by ventilating with nebulized 3N hydrochloric acid until a lower inflection point (LIP) appeared on the respiratory system pressure-volume loop. One group of 10 dogs was then ventilated for 4 hours with PEEP set below the LIP (low PEEP), whereas the remaining group of dogs was ventilated for the same time period with similar tidal volumes but with PEEP set above the LIP (high PEEP). We found histologic evidence of reduced alveolar volumes in the low-PEEP animals. However, there were no differences in neutrophil infiltration, lung lobe weights, pulmonary capillary hemorrhage or congestion, or arterial endothelin-1 concentration between the 2 protocol groups. In conclusion, we were unable to demonstrate that ventilation with PEEP set below the LIP exacerbates hydrochloric acid-induced lung injury in dogs.  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