3,502 research outputs found

    Evaluating the Integrity of Adhesive Bonds by the Measurement of Acoustic Properties under Stresses

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    Adhesively bonded components and structures are widely used in many critical aerospace applications. Several techniques have been developed to evaluate the integrity of adhesive bonds nondestructively. Most of the techniques rely on the ability to correlate the bond integrity to the behavior of the bondline region to elastic wave propagation. Testing for the relative rigidity between the adherend and adhesive layer at the bond interface will yield reliable information of the bond integrity. This can be achieved by either applying stress in the bondline region externally, or be induced internally

    Sports Coaches’ Knowledge and Beliefs About the Provision, Reception, and Evaluation of Verbal Feedback

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    Coach observation studies conducted since the 1970s have sought to determine the quantity and quality of verbal feedback provided by coaches to their athletes. Relatively few studies, however, have sought to determine the knowledge and beliefs of coaches that underpin this provision of feedback. The purpose of the current study was to identify the beliefs and knowledge that elite team sport coaches hold about providing, receiving and evaluating feedback in their training and competition environments. Semi-structured interviews conducted with 8 coaches were inductively analyzed, revealing three broad themes: thinking and learning about feedback, providing feedback, and evaluating feedback. Findings revealed a detailed array of knowledge about feedback across a wide range of sub-topics. Coaches saw feedback as a tool to improve performance, build athlete confidence, help athletes to monitor progress, and as a tool to improve their own performance. Novel insights about evaluating an athlete's reception of feedback, and tailoring feedback for individual athletes, were provided by coaches. The findings also highlight areas in which future coach education offerings can better support coaches to provide effective feedback

    Levosimendan for the prevention of acute organ dysfunction in sepsis

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    BACKGROUND Levosimendan is a calcium-sensitizing drug with inotropic and other properties that may improve outcomes in patients with sepsis. METHODS We conducted a double-blind, randomized clinical trial to investigate whether levosimendan reduces the severity of organ dysfunction in adults with sepsis. Patients were randomly assigned to receive a blinded infusion of levosimendan (at a dose of 0.05 to 0.2 μg per kilogram of body weight per minute) for 24 hours or placebo in addition to standard care. The primary outcome was the mean daily Sequential Organ Failure Assessment (SOFA) score in the intensive care unit up to day 28 (scores for each of five systems range from 0 to 4, with higher scores indicating more severe dysfunction; maximum score, 20). Secondary outcomes included 28-day mortality, time to weaning from mechanical ventilation, and adverse events. RESULTS The trial recruited 516 patients; 259 were assigned to receive levosimendan and 257 to receive placebo. There was no significant difference in the mean (±SD) SOFA score between the levosimendan group and the placebo group (6.68±3.96 vs. 6.06±3.89; mean difference, 0.61; 95% confidence interval [CI], −0.07 to 1.29; P=0.053). Mortality at 28 days was 34.5% in the levosimendan group and 30.9% in the placebo group (absolute difference, 3.6 percentage points; 95% CI, −4.5 to 11.7; P=0.43). Among patients requiring ventilation at baseline, those in the levosimendan group were less likely than those in the placebo group to be successfully weaned from mechanical ventilation over the period of 28 days (hazard ratio, 0.77; 95% CI, 0.60 to 0.97; P=0.03). More patients in the levosimendan group than in the placebo group had supraventricular tachyarrhythmia (3.1% vs. 0.4%; absolute difference, 2.7 percentage points; 95% CI, 0.1 to 5.3; P=0.04). CONCLUSIONS The addition of levosimendan to standard treatment in adults with sepsis was not associated with less severe organ dysfunction or lower mortality. Levosimendan was associated with a lower likelihood of successful weaning from mechanical ventilation and a higher risk of supraventricular tachyarrhythmia. (Funded by the NIHR Efficacy and Mechanism Evaluation Programme and others; LeoPARDS Current Controlled Trials number, ISRCTN12776039.

    Sprouty2 mediated tuning of signalling is essential for somite myogenesis

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    Background: Negative regulators of signal transduction cascades play critical roles in controlling different aspects of normal embryonic development. Sprouty2 (Spry2) negatively regulates receptor tyrosine kinases (RTK) and FGF signalling and is important in differentiation, cell migration and proliferation. In vertebrate embryos, Spry2 is expressed in paraxial mesoderm and in forming somites. Expression is maintained in the myotome until late stages of somite differentiation. However, its role and mode of action during somite myogenesis is still unclear. Results: Here, we analysed chick Spry2 expression and showed that it overlaps with that of myogenic regulatory factors MyoD and Mgn. Targeted mis-expression of Spry2 led to inhibition of myogenesis, whilst its C-terminal domain led to an increased number of myogenic cells by stimulating cell proliferation. Conclusions: Spry2 is expressed in somite myotomes and its expression overlaps with myogenic regulatory factors. Overexpression and dominant-negative interference showed that Spry2 plays a crucial role in regulating chick myogenesis by fine tuning of FGF signaling through a negative feedback loop. We also propose that mir-23, mir-27 and mir-128 could be part of the negative feedback loop mechanism. Our analysis is the first to shed some light on in vivo Spry2 function during chick somite myogenesis

    Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes

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    The Kondo-effect is a many-body phenomenon arising due to conduction electrons scattering off a localized spin. Coherent spin-flip scattering off such a quantum impurity correlates the conduction electrons and at low temperature this leads to a zero-bias conductance anomaly. This has become a common signature in bias-spectroscopy of single-electron transistors, observed in GaAs quantum dots as well as in various single-molecule transistors. While the zero-bias Kondo effect is well established it remains uncertain to what extent Kondo correlations persist in non-equilibrium situations where inelastic processes induce decoherence. Here we report on a pronounced conductance peak observed at finite bias-voltage in a carbon nanotube quantum dot in the spin singlet ground state. We explain this finite-bias conductance anomaly by a nonequilibrium Kondo-effect involving excitations into a spin triplet state. Excellent agreement between calculated and measured nonlinear conductance is obtained, thus strongly supporting the correlated nature of this nonequilibrium resonance.Comment: 21 pages, 5 figure

    Palliative care needs and integration of palliative care support in chronic obstructive pulmonary disease (COPD): a qualitative study

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    Background The provision of palliative care for severe chronic obstructive pulmonary disease (COPD) remains low resulting in unmet needs in patients and carers. Research Question This study aimed to 1) explore palliative care needs of patients living with severe COPD and their caregivers, 2) understand views of accessing and providing palliative care and factors influencing these experiences, and 3) explore to what extent palliative care and COPD services have been integrated. Study Design and Methods A multicentre qualitative study was undertaken in COPD services and specialist palliative care in the UK, involving patients with severe COPD, their carers and health professionals. Data were collected using semi-structured interviews and analysed using framework analysis. Themes were integrated using the constant comparison process, enabling systematic data synthesis. Results Four themes were generated from interviews with 20 patients, six carers and 25 health professionals: management of exacerbations, palliative care needs, access to palliative care and pathways, and integration of palliative care support. Uncertainty and fear were common in patients and carers, with identified needs for reassurance, rapid medical access, home care and finance advice. Timely palliative care was perceived as important by health professionals. Palliative care was integrated into COPD services although models of working varied across regions. Reliable screening tools and needs assessment, embedded psychological care and enhanced training in palliative care and communication skills were perceived important by health professionals for timely palliative care referrals and optimised management. Interpretation Palliative care is increasingly being implemented for non malignant diseases including COPD throughout the UK although models of working vary. A theoretical model is developed to illustrate the concept and pathway of the integration of palliative care support. A standardised screening and needs assessment tool is required to improve timely palliative care and address the significant needs of this population

    How Can I Drink Safely?; Perception Versus the Reality of Alcohol Consumption

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    This article investigates differences between perception and actual consumption of alcohol in young adults within the UK, suggesting that inaccurate information in the public domain may hamper those seeking to drink safely plus the development of moderate drinking cultures. Results confirm that inaccurate information may be preventing the development of safe drinking behaviours among certain groups. In addition, they indicate that some groups choose to ignore safe consumption limits in particular circumstances. Results indicate that many government strategies aimed at reducing unsafe drinking behaviour are inaccurately targeted; changing male public consumption behaviour may trigger changes in female behaviour

    Revisiting Date and Party Hubs: Novel Approaches to Role Assignment in Protein Interaction Networks

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    The idea of 'date' and 'party' hubs has been influential in the study of protein-protein interaction networks. Date hubs display low co-expression with their partners, whilst party hubs have high co-expression. It was proposed that party hubs are local coordinators whereas date hubs are global connectors. Here we show that the reported importance of date hubs to network connectivity can in fact be attributed to a tiny subset of them. Crucially, these few, extremely central, hubs do not display particularly low expression correlation, undermining the idea of a link between this quantity and hub function. The date/party distinction was originally motivated by an approximately bimodal distribution of hub co-expression; we show that this feature is not always robust to methodological changes. Additionally, topological properties of hubs do not in general correlate with co-expression. Thus, we suggest that a date/party dichotomy is not meaningful and it might be more useful to conceive of roles for protein-protein interactions rather than individual proteins. We find significant correlations between interaction centrality and the functional similarity of the interacting proteins.Comment: 27 pages, 5 main figures, 4 supplementary figure
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