502 research outputs found

    The electro-oxidation of methanol at platinum electrodes in acid solutions

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    The oxidation of methanol at smooth and porous, platinum and platinum/tin electrocatalysts in sulphuric acid solutions has been studied. The methods employed include linear sweep voltammetry and potentiometry at stationary and rotating electrodes. A microprocessor-based instrumental technique has been developed, which allows the simultaneous acquisition of steady-state polarisation data and a.c. impedance measurements. This system was based around a programmable potential controller used in conjunction with a frequency response analyser. [Continues.

    Cardiovascular Risk Assessment of Liver Transplantation Candidates

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    Single-Cell Imaging of Intracellular Ca 2ϩ and Phospholipase C Activity Reveals That RGS 2, 3, and 4 Differentially Regulate Signaling via the G␣ q/11 -Linked Muscarinic M 3 Receptor

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    ABSTRACT Using single cell, real-time imaging, this study compared the impact of members of the B/R4 subfamily of the regulators of G-protein signaling (RGS) (RGS2, -3, and -4) on receptor-mediated inositol 1,4,5-trisphosphate [Ins(1,4,5)P 3 ], diacylglycerol, and Ca 2ϩ signaling. In human embryonic kidney (HEK) 293 cells expressing recombinant G␣ q/11 -coupled muscarinic M 3 receptors, transient coexpression of RGS proteins with fluorescentlytagged biosensors for either Ins(1,4,5)P 3 or diacylglycerol demonstrated that RGS2 and 3 inhibited receptor-mediated events. Although gross indices of signaling were unaffected by RGS4, it slowed the rate of increase in Ins(1,4,5)P 3 levels. At equivalent levels of expression, myc-tagged RGS proteins showed inhibitory activity on the order RGS3 Ն RGS2 Ͼ RGS4. In HEK293 cells, stable expression of myc-tagged RGS2, -3, or -4 at equivalent levels also inhibited phosphoinositide and Ca 2ϩ signaling by endogenously expressed muscarinic M 3 receptors in the order RGS3 Ն RGS2 Ͼ RGS4. In these cells, RGS2 or -3 reduced receptor-mediated inositol phosphate generation in cell populations and reduced both the magnitude and kinetics (rise-time) of single cell Ca 2ϩ signals. Furthermore, at low levels of receptor activation, oscillatory Ca 2ϩ signals were dampened or abolished, whereas at higher levels, RGS2 and -3 promoted the conversion of more stable Ca 2ϩ elevations into oscillatory signals. Despite little or no effect on responses to maximal receptor activation, RGS4 produced effects on the magnitude, kinetics, and oscillatory behavior of Ca 2ϩ signaling at submaximal levels that were consistent with those of RGS2 and -3. The family of regulators of G-protein signaling (RGS) negatively regulate signaling by G-protein-coupled receptors (GPCRs) by binding to activated G␣-subunits and acting as either GTPase-activating proteins (GAPs) or effector antagonists RGS and RGS-like proteins have been classified into subfamilies based on the alignment of the RGS domain amino acid sequence

    Taking the heat or taking the temperature? A qualitative study of a large-scale exercise in seeking to measure for improvement, not blame.

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    Measurement of quality and safety has an important role in improving healthcare, but is susceptible to unintended consequences. One frequently made argument is that optimising the benefits from measurement requires controlling the risks of blame, but whether it is possible to do this remains unclear. We examined responses to a programme known as the NHS Safety Thermometer (NHS-ST). Measuring four common patient harms in diverse care settings with the goal of supporting local improvement, the programme explicitly eschews a role for blame. The study design was ethnographic. We conducted 115 hours of observation across 19 care organisations and conducted 126 interviews with frontline staff, senior national leaders, experts in the four harms, and the NHS-ST programme leadership and development team. We also collected and analysed relevant documents. The programme theory of the NHS-ST was based in a logic of measurement for improvement: the designers of the programme sought to avoid the appropriation of the data for any purpose other than supporting improvement. However, organisational participants - both at frontline and senior levels - were concerned that the NHS-ST functioned latently as a blame allocation device. These perceptions were influenced, first, by field-level logics of accountability and managerialism and, second, by specific features of the programme, including public reporting, financial incentives, and ambiguities about definitions that amplified the concerns. In consequence, organisational participants, while they identified some merits of the programme, tended to identify and categorise it as another example of performance management, rich in potential for blame. These findings indicate that the search to optimise the benefits of measurement by controlling the risks of blame remains challenging. They further suggest that a well-intentioned programme theory, while necessary, may not be sufficient for achieving goals for improvement in healthcare systems dominated by institutional logics that run counter to the programme theory

    Running a hospital patient safety campaign: a qualitative study

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    Purpose – Research on patient safety campaigns has mostly concentrated on large-scale multi-organisation efforts, yet locally led improvement is increasingly promoted. The purpose of this paper is to characterise the design and implementation of an internal patient safety campaign at a large acute National Health Service hospital trust with a view to understanding how to optimise such campaigns. Design/methodology/approach – The authors conducted a qualitative study of a campaign that sought to achieve 12 patient safety goals. The authors interviewed 19 managers and 45 frontline staff, supplemented by 56 hours of non-participant observation. Data analysis was based on the constant comparative method. Findings – The campaign was motivated by senior managers’ commitment to patient safety improvement, a series of serious untoward incidents, and a history of campaign-style initiatives at the trust. While the campaign succeeded in generating enthusiasm and focus among managers and some frontline staff, it encountered three challenges. First, though many staff at the sharp end were aware of the campaign, their knowledge, and acceptance of its content, rationale, and relevance for distinct clinical areas were variable. Second, the mechanisms of change, albeit effective in creating focus, may have been too limited. Third, many saw the tempo of the campaign as too rapid. Overall, the campaign enjoyed some success in raising the profile of patient safety. However, its ability to promote change was mixed, and progress was difficult to evidence because of lack of reliable measurement. Originality/value – The study shows that single-organisation campaigns may help in raising the profile of patient safety. The authors offer important lessons for the successful running of such campaigns.The Department of Health Policy Research programme as part of a wider programme of research on behavioural and cultural change to support quality and safety in the NHS. Write up of this paper was supported by a Wellcome Trust Senior Investigator award (MDW) WT097899
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