170 research outputs found

    Parallelized Hybrid Monte Carlo Simulation of Stress-Induced Texture Evolution

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    A parallelized hybrid Monte Carlo (HMC) methodology is devised to quantify the microstructural evolution of polycrystalline material under elastic loading. The approach combines a time explicit material point method (MPM) for the mechanical stresses with a calibrated Monte Carlo (cMC) model for grain boundary kinetics. The computed elastic stress generates an additional driving force for grain boundary migration. The paradigm is developed, tested, and subsequently used to quantify the effect of elastic stress on the evolution of texture in nickel polycrystals. As expected, elastic loading favors grains which appear softer with respect to the loading direction. The rate of texture evolution is also quantified, and an internal variable rate equation is constructed which predicts the time evolution of the distribution of orientations.Comment: 20 pages, 8 figure

    The relationship between nurse staffing and inpatient complications

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    Aim: To compare characteristics of hospitalizations with and without complications and examine the impact of nurse staffing on inpatient complications across different unit types. Background: Studies investigating the relationship between nurse staffing and inpatient complications have not shown consistent results. Methodological limitations have been cited as the basis for this lack of uniformity. Our study was designed to address some of these limitations. Design: Retrospective longitudinal hospitalization-level study. Method: Adult hospitalizations to high intensity, general medical and general surgical units at three metropolitan tertiary hospitals were included. Data were sourced from Western Australian Department of Health administrative data collections from 2004–2008. We estimated the impact of nurse staffing on inpatient complications adjusted for patient and hospital characteristics and accounted for patients with multiple hospitalizations. Results: The study included 256,984 hospitalizations across 58 inpatient units. Hospitalizations with complications had significantly different demographic characteristics compared with those without. The direction of the association between nurse staffing and inpatient complications was not consistent for different inpatient complications, nurse skill mix groups or for hospitalizations with different unit movement patterns. Conclusion: Our study design addressed limitations noted in the field, but our results did not support the widely held assumption that improved nurse staffing levels are associated with decreased patient complication rates. Despite a strong international focus on improving nurse staffing to reduce inpatient complications, our results suggest that adding more nurses is not a panacea for reducing inpatient complications to zero

    Oral health and elite sport performance

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    While the research base is limited, studies have consistently reported poor oral health in elite athletes since the first report from the 1968 Olympic Games. The finding is consistent both across selected samples attending dental clinics at major competitions and more representative sampling of teams and has led to calls from the International Olympic Committee for more accurate data on oral health. Poor oral health is an important issue directly as it can cause pain, negative effects on appearance and psychosocial effects on confidence and quality of life and may have long-term consequences for treatment burden. Self-reported evidence also suggests an impact on training and performance of athletes. There are many potential challenges to the oral health of athletes including nutritional, oral dehydration, exercise-induced immune suppression, lack of awareness, negative health behaviours and lack of prioritisation. However, in theory, oral diseases are preventable by simple interventions with good evidence of efficacy. The consensus statement aims to raise awareness of the issues of oral health in elite sport and recommends strategies for prevention and health promotion in addition to future research strategies

    The effect of aromatherapy massage with music on the stress and anxiety levels of emergency nurses

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    Introduction: Emergency department staff are subject to significant stressors during their work. Recent studies have provided links between high levels of stress and sick leave. Nurses who work in emergency and intensive care units and new graduates suffer from high levels of stress. This research evaluated the use of aromatherapy massage and music as an intervention to decrease the occupational stress and anxiety levels of emergency nurses. Methods: The study used a one group pretest-posttest, quasi-experimental design with random assignment. The degree of perceived occupational stress was assessed pre and post 12 weeks of aromatherapy massage and music. Anxiety levels were measured pre and post each massage session. The number of sick leave was also measured. Results: The findings indicate that aromatherapy massage and music significantly reduced anxiety levels. Although occupational stress levels were high in relation to workload there was no significant difference following the 12-week period of the intervention. Discussion: The use of a simple and time effective on-site stress reduction strategy significantly reduced nurses' anxiety levels. Regular on-site aromatherapy massage with music has the potential to increase the job satisfaction of the staff and decrease the number of sick leave. Further research examining the result of regular on site massage would be useful in determining long-term effects

    Nurse staffing, medical staffing and mortality in intensive care: an observational study

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    Objectives: To investigate whether the size of the workforce (nurses, doctors and support staff) has an impact of the survival chances of critically ill patients both in the intensive care unit (ICU) and in the hospital. Background: Investigations of intensive care outcomes suggest that some of the variation in patient survival rates might be related to staffing levels and workload, but the evidence is still equivocal. Data: Information about patients, including the outcome of care (whether the patient lived or died) came from the Intensive Care National Audit & Research Centre (ICNARC) Case Mix Programme. An Audit Commission survey of ICUs conducted in 1998 gave information about staffing levels. The merged dataset had information on 65 ICUs and 38,168 patients. This is currently the best available dataset for testing the relationship between staffing and outcomes in UK ICUs Design: A cross-sectional, retrospective, risk adjusted observational study. Methods: Multivariable, multilevel logistic regression. Outcome Measures: ICU and in-hospital mortality. Results: After controlling for patient characteristics and workload we found that higher numbers of nurses per bed and higher numbers of consultants were associated with higher survival rates. Further exploration revealed that the number of nurses had the greatest impact on patients at high risk of death whereas the effect of medical staffing was across the range of patient acuity. No relationship between patient outcomes and the number of support staff was found. Distinguishing between direct care and supernumerary nurses and restricting the analysis to patients who had been in the unit for more than 8 hours made little difference to the results. Separate analysis of in-unit and in-hospital survival showed that the clinical workforce in intensive care had a greater impact on ICU mortality than on hospital mortality which gives the study additional credibility. Conclusion: This study supports claims that the availability of medical and nursing staff is associated with the survival of critically ill patients and suggests that future studies should focus on the resources of the health care team. The results emphasise the urgent need for a prospective study of staffing levels and the organisation of care in ICUs

    Nurse staffing, direct nursing care hours and patient mortality in Taiwan: the longitudinal analysis of hospital nurse staffing and patient outcome study

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    <p>Abstract</p> <p>Background</p> <p>Studies over the past decades have shown an association between nurse staffing and patient outcomes, however, most of these studies were conducted in the West. Accordingly, the purpose of this study aimed to provide an overview of the research/evidence base which has clarified the relationship between nurse staffing and patient mortality of acute care hospital wards under a universal health insurance system and attempted to provide explanations for some of the phenomena that are unique in Taiwan.</p> <p>Methods</p> <p>Through stratified random sampling, a total of 108 wards selected from 32 hospitals in Taiwan were collected over a consecutive seven month period. The mixed effect logit model was used to explore the relationship between nurse staffing and patient mortality.</p> <p>Results</p> <p>The medians of direct-nursing-care-hour, and nurse manpower were 2.52 h, and 378 persons, respectively. The OR for death between the long direct-nursing-care-hour (> median) group and the short direct-nursing-care-hour (≦median) group was 0.393 (95% CI = [0.245, 0.617]). The OR for death between the high (> median) and the low (≦median) nurse manpower groups was 0.589 (95% CI = [0.381, 0.911]).</p> <p>Conclusions</p> <p>Findings from this study demonstrate an association of nurse staffing and patient mortality and are consistent with findings from similar studies. These findings have policy implications for strengthening the nursing profession, nurse staffing, and the hospital quality associated with nursing. Additional research is necessary to demonstrate adequate nurse staffing ratios of different wards in Taiwan.</p

    Identifying paediatric nursing-sensitive outcomes in linked administrative health data

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    There is increasing interest in the contribution of the quality of nursing care to patient outcomes. Due to different casemix and risk profiles, algorithms for administrative health data that identify nursing-sensitive outcomes in adult hospitalised patients may not be applicable to paediatric patients. The study purpose was to test adult algorithms in a paediatric hospital population and make amendments to increase the accuracy of identification of hospital acquitted events. The study also aimed to determine whether the use of linked hospital records improved the likelihood of correctly identifying patient outcomes as nursing sensitive rather than being related to their pre-morbid conditions. Algorithm for nursing-sensitive outcomes used in adult populations have to be amended before application to paediatric populations. Using unlinked individual hospitalisation records to estimate rates of nursing-sensitive outcomes is likely to result in inaccurate rates

    The dislocation behaviour and GND development in a nickel based superalloy during creep

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    In the current study, dislocation activity and storage during creep deformation in a nickel based superalloy (Waspaloy) were investigated, focussing on the storage of geometrically necessary (GND) and statistically stored (SSD) dislocations. Two methods of GND density calculation were used, namely, EBSD Hough Transformation and HR-EBSD Cross Correlation based methods. The storage of dislocations, including SSDs, was investigated by means of TEM imaging. Here, the concept of GND accumulation in soft and hard grains and the effect of neighbouring grain orientation on total dislocation density was examined. Furthermore, the influence of applied stress (below and above the yield stress of Waspaloy) during creep on deformation micro-mechanism and dislocation density was studied. It was demonstrated that soft grains provided pure shear conditions on at least two octahedral (111) slip systems for easy dislocation movement. This allowed dislocations to reach the grain boundary without significant geometrically necessary dislocation accumulation in the centre of the grain. Hence, the majority of the soft grains appeared to have minimum GND density in the centre of the grain with high GND accumulation in the vicinity of the grain boundaries. However, the values and width of accumulated GND depended on the surrounding grain orientations. Furthermore, it was shown that the hard grains were not favourably oriented for octahedral slip system activation leading to a grain rotation in order to activate any of the available slip systems. Eventually, (i) the hard grain resistance to deformation and (ii) neighbouring grain resistance for the hard grain reorientation caused high GND density on a number of octahedral (111) slip systems. The results also showed that during creep below the yield stress of Waspaloy (500 MPa/700 °C), the GND accumulation was relatively low due to the insufficient macroscopic stress level. However, the regions near grain boundaries showed high GND density. At 800 MPa/700 °C (above yield at this temperature), in addition to the movement of pre-existing dislocations (SSD and GND) at a higher mobility rate, large numbers of dislocations were generated and moved toward the grain boundaries. This resulted in a much higher GND density but narrower width of high intensity GNDs near the grain boundaries. It is concluded that although GND measurement by means of EBSD can provide great insight into dislocation accumulation and its behaviour, it is critical to consider SSD type which also contributes to the strain hardening of the material

    ANSI/NISO Z39.99-2017 ResourceSync Framework Specification

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    This ResourceSync specification describes a synchronization framework for the web consisting of various capabilities that allow third-party systems to remain synchronized with a server’s evolving resources. The capabilities may be combined in a modular manner to meet local or community requirements. This specification also describes how a server should advertise the synchronization capabilities it supports and how third-party systems may discover this information. The specification repurposes the document formats defined by the Sitemap protocol and introduces extensions for them

    Regulation of Thromboxane Receptor Signaling at Multiple Levels by Oxidative Stress-Induced Stabilization, Relocation and Enhanced Responsiveness

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    Thromboxane A(2) (TxA(2)) is a major, unstable arachidonic acid metabolite, and plays a key role in normal physiology and control of vascular tone. The human thromboxane receptor (TPβ), expressed in COS-7 cells, is located predominantly in the endoplasmic reticulum (ER). Brief hydrogen peroxide exposure increases the efficiency of translocation of TPβ from the ER into the Golgi complex, inducing maturation and stabilization of TPβ. However, the ultimate fate of this post-ER TPβ pool is not known, nor is its capacity to initiate signal transduction. Here we specifically assessed if functional TPβ was transported to the plasma membrane following H(2)O(2) exposure.We demonstrate, by biotinylation and confocal microscopy, that exposure to H(2)O(2) results in rapid delivery of a cohort of TPβ to the cell surface, which is stable for at least eight hours. Surface delivery is brefeldin A-sensitive, indicating that translocation of this receptor cohort is from internal pools and via the Golgi complex. H(2)O(2) treatment results in potentiation of the increase to intracellular calcium concentrations in response to TPβ agonists U46619 and 8-iso PGF(2α) and also in the loss of ligand-dependent receptor internalization. Further there is increased responsiveness to a second application of the agonist. Finally we demonstrate that the effect of H(2)O(2) on stimulating surface delivery is shared with the FP prostanoid receptor but not the EP3 or EP4 receptors.In summary, brief exposure to H(2)O(2) results in an immediate and sustained increase in the surface pool of thromboxane receptor that is capable of mediating a persistent hyper-responsiveness of the cell and suggests a highly sophisticated mechanism for rapidly regulating thromboxane signaling
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