158 research outputs found
Dosimetry experiments at the MEDUSA Facility (Little Mountain).
A series of experiments on the MEDUSA linear accelerator radiation test facility were performed to evaluate the difference in dose measured using different methods. Significant differences in dosimeter-measured radiation dose were observed for the different dosimeter types for the same radiation environments, and the results are compared and discussed in this report
Measurements of prompt radiation induced conductivity in Teflon (PTFE).
We performed measurements of the prompt radiation induced conductivity (RIC) in thin samples of Teflon (PTFE) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil (76.2 microns) samples were irradiated with a 0.5 %CE%BCs pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E11 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Details of the experimental apparatus and analysis are reported in this report on prompt RIC in Teflon
Hospital nurse-staffing models and patient- and staff-related outcomes
Background: Nurses comprise the largest component of the health workforce worldwide and numerous models of workforce allocation and profile have been implemented. These include changes in skill mix, grade mix or qualification mix, staffâallocation models, staffing levels, nursing shifts, or nursesâ work patterns. This is the first update of our review published in 2011. Objectives: The purpose of this review was to explore the effect of hospital nurseâstaffing models on patient and staffârelated outcomes in the hospital setting, specifically to identify which staffing model(s) are associated with: 1) better outcomes for patients, 2) better staffârelated outcomes, and, 3) the impact of staffing model(s) on cost outcomes. Search methods: CENTRAL, MEDLINE, Embase, two other databases and two trials registers were searched on 22 March 2018 together with reference checking, citation searching and contact with study authors to identify additional studies. Selection criteria: We included randomised trials, nonârandomised trials, controlled beforeâafter studies and interruptedâtimeâseries or repeatedâmeasures studies of interventions relating to hospital nurseâstaffing models. Participants were patients and nursing staff working in hospital settings. We included any objective reported measure of patientâ, staffârelated, or economic outcome. The most important outcomes included in this review were: nursingâstaff turnover, patient mortality, patient readmissions, patient attendances at the emergency department (ED), length of stay, patients with pressure ulcers, and costs. Data collection and analysis: We worked independently in pairs to extract data from each potentially relevant study and to assess risk of bias and the certainty of the evidence. Main results: We included 19 studies, 17 of which were included in the analysis and eight of which we identified for this update. We identified four types of interventions relating to hospital nurseâstaffing models: introduction of advanced or specialist nurses to the nursing workforce; introduction of nursing assistive personnel to the hospital workforce; primary nursing; and staffing models. The studies were conducted in the USA, the Netherlands, UK, Australia, and Canada and included patients with cancer, asthma, diabetes and chronic illness, on medical, acute care, intensive care and longâstay psychiatric units. The risk of bias across studies was high, with limitations mainly related to blinding of patients and personnel, allocation concealment, sequence generation, and blinding of outcome assessment. The addition of advanced or specialist nurses to hospital nurse staffing may lead to little or no difference in patient mortality (3 studies, 1358 participants). It is uncertain whether this intervention reduces patient readmissions (7 studies, 2995 participants), patient attendances at the ED (6 studies, 2274 participants), length of stay (3 studies, 907 participants), number of patients with pressure ulcers (1 study, 753 participants), or costs (3 studies, 617 participants), as we assessed the evidence for these outcomes as being of very low certainty. It is uncertain whether adding nursing assistive personnel to the hospital workforce reduces costs (1 study, 6769 participants), as we assessed the evidence for this outcome to be of very low certainty. It is uncertain whether primary nursing (3 studies, > 464 participants) or staffing models (1 study, 647 participants) reduces nursingâstaff turnover, or if primary nursing (2 studies, > 138 participants) reduces costs, as we assessed the evidence for these outcomes to be of very low certainty. Authors' conclusions: The findings of this review should be treated with caution due to the limited amount and quality of the published research that was included. We have most confidence in our finding that the introduction of advanced or specialist nurses may lead to little or no difference in one patient outcome (i.e. mortality) with greater uncertainty about other patient outcomes (i.e. readmissions, ED attendance, length of stay and pressure ulcer rates). The evidence is of insufficient certainty to draw conclusions about the effectiveness of other types of interventions, including new nurseâstaffing models and introduction of nursing assistive personnel, on patient, staff and cost outcomes. Although it has been seven years since the original review was published, the certainty of the evidence about hospital nurse staffing still remains very low
Stress Imaging Use and Repeat Revascularization Among Medicare Patients With High-Risk Coronary Artery Disease
The optimal use of stress testing after coronary revascularization remains unclear, and over-utilization of stress testing may increase rates of repeat revascularization. We analyzed the relationship at both the patient and regional level between the use of stress testing and repeat revascularization for a cohort of Medicare beneficiaries receiving revascularization within 30 days of an admission for symptomatic coronary artery disease (CAD).The sample consisted of 219,748 Medicare beneficiaries older than 65 years who received percutaneous coronary intervention (PCI) or cardiac bypass surgery (CABG) following hospital admission for symptomatic CAD in 2003â2004. Medicare claims data through 2008 identified the use of stress testing and repeat revascularization. Associations between the cumulative incidence of stress testing and repeat revascularization were analyzed using linear regressions. Within six years of initial revascularization, the cumulative incidence of events was 0.61 for stress testing and 0.23 for repeat revascularization. Most (53.1%) repeat revascularizations were preceded by a stress test. Only 10.3% of repeat revascularization procedures were preceded by myocardial infarction. Four-year cumulative incidence of repeat revascularization and stress testing varied between the Hospital Referral Regions represented by the sample, and the positive correlation between the rates by HRR accounted for only a small portion of the total HRR variation in revascularization rates. Stress testing is commonly performed among Medicare patients after initial revascularization, and the majority of repeat procedures are performed for stable CAD. Variation in stress testing patterns only explains a modest fraction of regional variation in repeat revascularization rates
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Spectral unfolds of PITHON Flash X-ray source.
Using a differential absorption spectrometer we obtained experimental spectral information for the PITHON Flash X-ray Machine located in San Leandro, California at L-3 Communications. Spectral information we obtained pertained to the 200 keV to 800 keV endpoint operation of PITHON. We also obtained data on the temporal behavior of high energy and low energy spectral content
Three-Year Outcomes of Multivessel Revascularization in Very Elderly Acute Coronary Syndrome Patients
Comparative effectiveness of interventional treatment strategies for the very elderly with acute coronary syndrome remains poorly defined due to study exclusions. Interventions include percutaneous coronary intervention (PCI), usually with stents, or coronary artery bypass grafting (CABG). The elderly are frequently directed to PCI because of provider perceptions that PCI is at therapeutic equipoise with CABG and that CABG incurs increased risk. We evaluated long-term outcomes of CABG versus PCI in a cohort of very elderly Medicare beneficiaries presenting with acute coronary syndrome
Health equity in the New Zealand health care system: a national survey
<p>Abstract</p> <p>Introduction</p> <p>In all countries people experience different social circumstances that result in avoidable differences in health. In New Zealand, MÄori, Pacific peoples, and those with lower socioeconomic status experience higher levels of chronic illness, which is the leading cause of mortality, morbidity and inequitable health outcomes. Whilst the health system can enable a fairer distribution of good health, limited national data is available to measure health equity. Therefore, we sought to find out whether health services in New Zealand were equitable by measuring the level of development of components of chronic care management systems across district health boards. Variation in provision by geography, condition or ethnicity can be interpreted as inequitable.</p> <p>Methods</p> <p>A national survey of district health boards (DHBs) was undertaken on macro approaches to chronic condition management with detail on cardiovascular disease, chronic obstructive pulmonary disease, congestive heart failure, stroke and diabetes. Additional data from expert informant interviews on program reach and the cultural needs of MÄori and Pacific peoples was sought. Survey data were analyzed on dimensions of health equity relevant to strategic planning and program delivery. Results are presented as descriptive statistics and free text. Interviews were transcribed and NVivo 8 software supported a general inductive approach to identify common themes.</p> <p>Results</p> <p>Survey responses were received from the majority of DHBs (15/21), some PHOs (21/84) and 31 expert informants. Measuring, monitoring and targeting equity is not systematically undertaken. The Health Equity Assessment Tool is used in strategic planning but not in decisions about implementing or monitoring disease programs. Variable implementation of evidence-based practices in disease management and multiple funding streams made program implementation difficult. Equity for MÄori is embedded in policy, this is not so for other ethnic groups or by geography. Populations that conventional practitioners find hard to reach, despite recognized needs, are often underserved. Nurses and community health workers carried a disproportionate burden of care. Cultural and diversity training is not a condition of employment.</p> <p>Conclusions</p> <p>There is a struggle to put equity principles into practice, indicating will without enactment. Equity is not addressed systematically below strategic levels and equity does not shape funding decisions, program development, implementation and monitoring. Equity is not incentivized although examples of exceptional practice, driven by individuals, are evident across New Zealand.</p
Evaluating the effectiveness of a rapidly adopted cardiovascular technology with administrative data: The case of drug-eluting stents for acute coronary syndromes
Instrumental variable (IV) methods can correct for unmeasured confounding when using administrative (claims) data for cardiovascular outcomes research, but difficulties identifying valid IVs have limited their use. We evaluated the safety and efficacy of drug-eluting coronary stents (DES) compared to bare metal stents (BMS) for Medicare beneficiaries with acute coronary syndromes (ACS) using the rapid uptake of DES in clinical practice as an instrument. We compared results from IV to those from propensity score matching (PSM) and multivariable regression models
Gristhorpe Man: an Early Bronze Age log-coffin burial scientifically defined
Š 2010 Antiquity PublicationsA log-coffin excavated in the early nineteenth century proved to be well enough preserved in the early twenty-first century for the fill armoury of modern scientific investigation to give its occupants and contents new identity, new origins and a new date. In many ways the interpretation is much the same as before: a local big man buried looking out to sea. Modern analytical techniques can create a person more real, more human and more securely anchored in history. This research team shows how.The project has been funded by grants from the British Academy, British Association for
the Advancement of Science, Natural Environment Research Council, Royal Archaeological
Institute and Scarborough Museums Trust. CJKâs participation in this project was funded
by a Leverhulme Research Fellowship (RF/6/RFG/2008/0253)
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