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   457篇
  免费   20篇
  国内免费   1篇
耳鼻咽喉   7篇
儿科学   7篇
基础医学   43篇
口腔科学   1篇
临床医学   79篇
内科学   138篇
神经病学   15篇
特种医学   17篇
外科学   101篇
综合类   7篇
预防医学   25篇
眼科学   1篇
药学   16篇
肿瘤学   21篇
  2024年   1篇
  2023年   5篇
  2022年   10篇
  2021年   23篇
  2020年   6篇
  2019年   20篇
  2018年   18篇
  2017年   16篇
  2016年   13篇
  2015年   10篇
  2014年   29篇
  2013年   23篇
  2012年   32篇
  2011年   24篇
  2010年   11篇
  2009年   17篇
  2008年   24篇
  2007年   23篇
  2006年   33篇
  2005年   35篇
  2004年   42篇
  2003年   16篇
  2002年   29篇
  2001年   7篇
  2000年   4篇
  1999年   2篇
  1985年   2篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
排序方式: 共有478条查询结果,搜索用时 156 毫秒
411.
Li J  Fine JP  Safdar N 《Statistics in medicine》2007,26(17):3258-3273
We study prevalence-dependent diagnostic accuracy measures, specifically, positive and negative predictive values. These measures permit an assessment of the clinical utility of diagnostic tests across populations with different disease prevalences. In many cases, prevalence may not be known with certainty and the evaluation of the diagnostic tests must account for this uncertainty. A sensitivity analysis may be desired across a prevalence continuum defining low to high-risk populations. For this scenario, simultaneous inference about the predictive values across a range of prevalences is proposed. For situations where a non-point prior distribution on prevalence is specified, we suggest inferences based on averaging the accuracy measures with respect to the prior, leading to simple numerical summaries. The methods are illustrated in a meta-analysis of diagnostic tests for intravascular device-related bloodstream infection, where the prevalence may vary widely both within and across populations.  相似文献   
412.
Stroke care is a time-sensitive workflow involving multiple specialties acting in unison, often relying on one-way paging systems to alert care providers. The goal of this study was to map and quantitatively evaluate such a system and address communication gaps with system improvements. A workflow process map of the stroke notification system at a large, urban hospital was created via observation and interviews with hospital staff. We recorded pager communication regarding 45 patients in the emergency department (ED), neuroradiology reading room (NRR), and a clinician residence (CR), categorizing transmissions as successful or unsuccessful (dropped or unintelligible). Data analysis and consultation with information technology staff and the vendor informed a quality intervention—replacing one paging antenna and adding another. Data from a 1-month post-intervention period was collected. Error rates before and after were compared using a chi-squared test. Seventy-five pages regarding 45 patients were recorded pre-intervention; 88 pages regarding 86 patients were recorded post-intervention. Initial transmission error rates in the ED, NRR, and CR were 40.0, 22.7, and 12.0 %. Post-intervention, error rates were 5.1, 18.8, and 1.1 %, a statistically significant improvement in the ED (p?<?0.0001) and CR (p?=?0.004) but not NRR (p?=?0.208). This intervention resulted in measureable improvement in pager communication to the ED and CR. While results in the NRR were not significant, this intervention bolsters the utility of workflow process maps. The workflow process map effectively defined communication failure parameters, allowing for systematic testing and intervention to improve communication in essential clinical locations.  相似文献   
413.

Background

Nontraumatic, spontaneous rupture of the ascending aorta is rare and the etiology is largely unknown.

Methods

We reviewed seven patients from our institution, with no known aortic disease or hereditary connective tissue disorder that presented with spontaneous ascending aortic rupture from 2012 to 2017.

Results

Most patients presented with non‐radiating chest pain along with hypertension (71.4%). The mean ascending aortic diameter at rupture was 4.60 ± 0.62 cm. The median door‐to‐operating room time was 2.58 h, resulting from effective implementation of an aortic emergency protocol. There were no operative mortalities.

Conclusions

In patients with ascending aortic rupture, aortic diameter may not always correlate with the risk of rupture. Rapid diagnosis combined with a multidisciplinary approach is vital for the successful management of these high‐risk patients.  相似文献   
414.

Diversity enhances the performance of the healthcare system by providing better patient outcomes and reducing physician burnout. In this study, we explored the gender and racial trends in the recruitment of women and racial minorities into forensic psychiatry fellowship programs in the US. Retrospective data analysis was performed by utilizing the data from the Accreditation Council for Graduate Medical Education (ACGME)’s annual Data Resource Books from the year 2007 to 2021. Demographic data, including gender and race, were extracted for forensic psychiatry fellows. The number of female trainees increased significantly to become a majority, i.e., 58.8% of all forensic psychiatry trainees in 2020–2021 were female compared to 27.78% of women forensic psychiatry fellows in 2007–08. Between 2011–12 and 2020–2021, there was a relative increase in White (Non-Hispanic), Asian/Pacific Islander and Black (Non-Hispanic) forensic psychiatry fellows, by 54.75%, 114.4%, and 0.36% respectively. Despite the overall increase in the numbers of ethnic minorities in US psychiatry residency and fellowship programs, racial minorities remain significantly under-represented in forensic psychiatry fellowship programs. We need to revise policies to promote underrepresented minorities in medicine (URMM) in forensic psychiatry.

  相似文献   
415.
Since the 1990s, changing trends have been documented in species distribution and susceptibility to bloodstream infections caused by Candida species in cancer patients. However, few data are available regarding the association between in vitro antifungal susceptibility and outcome of candidemia in this patient population. We therefore evaluated the association of in vitro antifungal susceptibility and other risk factors with failure of initial antifungal therapy in cancer patients with candidemia. Candidemia cases in cancer patients from 1998 to 2001 (n = 144) were analyzed retrospectively along with their in vitro susceptibility to amphotericin B, fluconazole, and itraconazole (National Committee for Clinical and Laboratory Standards M27-A method). Patients were evaluable for outcome analysis if they received continuous unchanged therapy with either fluconazole or amphotericin B for >/=5 days. We excluded cases of mixed candidemia. In vitro susceptibility testing data of the first Candida bloodstream isolate were analyzed. Appropriate therapy was defined as that using an active in vitro antifungal for >/=5 days. For fluconazole susceptible-dose dependent Candida species, we defined appropriate therapy as a fluconazole dose of >/=600 mg/day. The Candida species distribution was 30% Candida albicans, 24% Candida glabrata, 23% Candida parapsilosis, 10% Candida krusei, 9% Candida tropicalis, and 3% other. Overall, amphotericin B was the most active agent in vitro, with only 3% of the isolates exhibiting resistance to it (>1 mg/L). Dose-dependent susceptibility to fluconazole and itraconazole was seen in 13% and 21% of the isolates, respectively, while resistance to fluconazole and itraconazole was seen in 13% and 26%, respectively.Eighty patients were evaluable for outcome analysis. In multivariate analysis, the following factors emerged as independent predictors of failure of initial antifungal therapy: leukemia (p = 0.01), bone marrow transplantation (p = 0.006), and intensive care unit stay at onset of infection (p = 0.02). Inappropriate antifungal therapy, as defined by daily dose and in vitro susceptibility, was not shown consistently to be a significant factor (it was significant in multivariate analysis, p = 0.04, but not in univariate analysis), indicating the complexity of the variables that influence the response to antifungal treatment in cancer patients with candidemia.  相似文献   
416.
BackgroundPostural orthostatic tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance associated with a significant symptom burden. Compression garments are a frequently prescribed treatment, but the effectiveness of waist-high compression has not been evaluated in adults with POTS.ObjectivesThis study evaluated compression garments as a treatment for POTS using a head-up tilt test (HUT), and a noninflatable core and lower body compression garment.MethodsThirty participants completed 10-min HUT with each of 4 compression conditions in a randomized crossover design. The conditions were no compression (NONE), lower leg compression (LEG), abdominal/thigh compression (ABDO), and full abdominal/leg compression (FULL). Heart rate, beat-to-beat blood pressure, and Vanderbilt Orthostatic Symptom Score ratings were measured during each HUT.ResultsThe compression garment reduced heart rate (NONE: 109 ± 19 beats/min; LEG: 103 ± 16 beats/min; ABDO: 97 ± 15 beats/min; FULL: 92 ± 14 beats/min; p < 0.001) and improved symptoms (p < 0.001) during HUT in a dose-dependent manner. During HUT, stroke volume and systolic blood pressure were better maintained with FULL and ABDO compression compared with LEG and NONE compression.ConclusionsAbdominal and lower body compression reduced heart rate and improved symptoms during HUT in adult patients with POTS. These effects were driven by improved stroke volume with compression. Abdominal compression alone might also provide a clinical benefit if full lower body compression is not well tolerated. (Hemodynamic Effects of Compression in POTS; NCT03484273)  相似文献   
417.
In the current era of multidrug-resistant organisms, the clinical spectrum of Streptococcus pneumoniae infection remains unclear, especially in immunosuppressed patients with cancer. We sought to define the characteristics of pneumococcal bacteremia in patients who were receiving care at a comprehensive cancer center. All consecutive episodes of S. pneumoniae bacteremia between January 1998 and December 2002 were evaluated retrospectively. One hundred thirty-five episodes of pneumococcal bacteremia occurred in 122 patients. Sixty-three (52%) of 122 patients had hematologic malignancies; the others had solid tumors. The median Acute Physiology and Chronic Health Evaluation II score was 14 +/- 5. Twenty-four episodes (18%) occurred during neutropenia (<500 cells/microL). Sixty-five patients (53%) were receiving antineoplastic therapy, and 36 (30%) were receiving systemic corticosteroids. Twelve (41%) of 29 hematopoietic stem cell transplant (HSCT) recipients had received transplantation within 12 months of the infection diagnosis; 11 patients had graft-versus-host disease (chronic in 10). In 27 episodes (22%), S. pneumoniae bacteremia was considered as a breakthrough infection. Nine (56%) of 16 hospital-acquired episodes of S. pneumoniae bloodstream infection occurred in patients with profound neutropenia, whereas 15 (13%) of 119 episodes of community-acquired infection occurred during neutropenia (p < 0.0002). In 91 episodes (67%), patients had radiographic evidence of pneumonia. Infected catheters were associated with 21 episodes (16%). Forty-eight (36%) of 135 isolates were not susceptible to penicillin (minimum inhibitory concentration [MIC] > or = 2 microg/mL); 9 (7%) showed intermediate susceptibility to ceftriaxone (MIC >0.5 and <2.0 microg/mL). Nineteen patients (16%) died within 2 weeks of diagnosis; 18 deaths were attributed to systemic pneumococcal infection. Univariate analysis showed no significant increase in the risk of short-term death in patients with infection due to penicillin non-susceptible organisms (OR [odds ratio], 1.47; 95% confidence intervals [CI], 0.53-4.05; p < 0.46), initially discordant treatment (OR, 1.0; 95% CI, 0.62-665.4; p < 0.16), presence of pneumonia (OR, 1.19; 95% CI, 0.39-3.62; p < 0.76), neutropenia (OR, 1.0; 95% CI, 0.28-4.09; p < 0.92), systemic corticosteroid use (OR, 1.96; 95% CI, 0.69-5.60; p < 0.21), or antineoplastic therapy (OR, 1.45; 95% CI, 1.52-4.05; p < 0.47). Similarly, patients with hematologic cancers compared to those with solid cancers (OR, 1.0; 95% CI, 0.49-3.70; p < 0.56) and recipients of HSCT compared to those with no history of transplantation (OR, 1.0; 95% CI 0.59-12.71; p < 0.20) did not have a less favorable outcome. In conclusion, most pneumococcal bloodstream infections were community acquired, although hospital-acquired infections were common in neutropenic patients. It is noteworthy that initially discordant therapy, penicillin non-susceptible S. pneumoniae, and other conventional predictors of unfavorable outcome were not associated with increased mortality rates in these high-risk patients with cancer.  相似文献   
418.
BACKGROUND: No information is available on the financial impact of nosocomial pneumonia in Argentina. To calculate the cost of nosocomial pneumonia in intensive care units, a 5-year, matched cohort study was undertaken at 3 hospitals in Argentina. SETTING: Six adult intensive care units (ICU). METHODS: Three hundred seven patients with nosocomial pneumonia (exposed) and 307 patients without nosocomial pneumonia (unexposed) were matched for hospital, ICU type, year admitted to study, length of stay more than 7 days, sex, age, antibiotic use, and average severity of illness score (ASIS). The patient's length of stay (LOS) in the ICU was obtained prospectively in daily rounds, the cost of a day was provided by the hospital's finance department, and the cost of antibiotics prescribed for nosocomial pneumonia was provided by the hospital's pharmacy department. RESULTS: The mean extra LOS for 307 cases (compared with controls) was 8.95 days, the mean extra antibiotic defined daily doses (DDD) was 15, the mean extra antibiotic cost was $996, the mean extra total cost was $2255, and the extra mortality was 30.3%. CONCLUSIONS: Nosocomial pneumonia results in significant patient morbidity and consumes considerable resources. In the present study, patients with nosocomial pneumonia had significant prolongation of hospitalization, cost, and a high extra mortality. The present study illustrates the potential cost savings of introducing interventions to reduce nosocomial pneumonia. To our knowledge, this is the first study evaluating this issue in Argentina.  相似文献   
419.
Surgical management of metastatic spine tumors   总被引:3,自引:0,他引:3  
Recent advances in diagnostic tests and radiologic imaging, and the development of novel chemotherapeutic agents and radiation methods have greatly altered the treatment options in patients who have spinal tumors. Improvements in fundamental understanding of the mechanisms of bone metastases, developments in spinal instrumentation, and recent introduction of recombinant bone morphogenetic proteins for spinal reconstruction offer promising strategies in selected patients. Clear applications of the fundamental surgical oncology still apply to spinal tumors. This article considers recent advances in management of the metastatic tumors to the spine.  相似文献   
420.

Background

Surgeon volume has been identified as an important factor impacting postoperative outcome in patients undergoing orthopedic surgeries. With an absence of a detailed systematic review, we sought to collate evidence on the impact of surgeon volume on postoperative outcomes in patients undergoing primary total hip arthroplasty.

Methods

PubMed (MEDLINE) and Google Scholar databases were queried for articles using the following search criteria: (“Surgeon Volume” OR “Provider Volume” OR “Volume Outcome”) AND (“THA” OR “Total hip replacement” OR “THR” OR “Total hip arthroplasty”). Studies investigating total hip arthroplasty being performed for malignancy or hip fractures were excluded from the review. Twenty-eight studies were included in the final review. All studies underwent a quality appraisal using the GRADE tool. The systematic review was performed in accordance with the PRISMA guidelines.

Results

Increasing surgeon volume was associated with a shorter length of stay, lower costs, and lower dislocation rates. Studies showed a significant association between an increasing surgeon volume and higher odds of early-term and midterm survivorship, but not long-term survivorships. Although complications were reported and recorded differently in studies, there was a general trend toward a lower postoperative morbidity with regard to complications following surgeries by a high-volume surgeon.

Conclusion

This systematic review shows evidence of a trend toward better postoperative outcomes with high-volume surgeons. Future prospective studies are needed to better determine long-term postoperative outcomes such as survivorship before healthcare policies such as regionalization and/or equal-access healthcare systems can be considered.  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