1,344 research outputs found

    Cadmium sulfide in a Mesoproterozoic terrestrial environment

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    Ions in solution: Density Corrected Density Functional Theory (DC-DFT)

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    Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HO\cdotCl^- and HO\cdotH2_2O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent

    Barriers and facilitators for the use of NURSING bedside handovers : implications for evidence‐based practice

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    BACKGROUND: Previous studies on bedside handovers have identified nurse-related barriers and facilitators for implementing bedside handovers, but have neglected the existing ward's nursing care system as an important influencing factor. AIMS: To determine the association between the existing nursing care system (i.e., decentralized, two-tier, or centralized) on a ward and the barriers and facilitators of the bedside handover. METHODS: Structured individual interviews (N = 106) on 14 nursing wards in eight hospitals were performed before implementation of bedside handovers. The structured interview guide was based on a narrative review. Direct content analysis was used to determine the nursing care system of a ward and the degree to which barriers and facilitators were present. Pearson's Chi-square analysis was used to determine whether there were associations between the nursing care systems concerning the presence of barriers and facilitators for implementing bedside handovers. RESULTS: Twelve barriers and facilitators were identified, of which three are new to literature: the possible loss of opportunities for socializing, collegiality, and overview; head nurse's role; and role of colleagues. The extent to which barriers and facilitators were present differed across nursing care systems, with the exception of breach of confidentiality (barrier), and an existing structured handover (facilitator). Overall, nurses working in decentralized nursing care systems report fewer barriers against and more facilitators in favor of using bedside handovers than nurses in two-tier or centralized systems. LINKING EVIDENCE TO ACTION: Before implementing bedside handovers, the context of the nursing care system may be considered to determine the most effective process to implement change. Based on these study findings, implementing bedside handovers could be more challenging on wards with a two-tier or centralized care system

    Proton acceleration by irradiation of isolated spheres with an intense laser pulse

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    We report on experiments irradiating isolated plastic spheres with a peak laser intensity of 2-3 x 10(20) W cm(-2). With a laser focal spot size of 10 mu m full width half maximum (FWHM) the sphere diameter was varied between 520 nm and 19.3 mu m. Maximum proton energies of similar to 25 MeV are achieved for targets matching the focal spot size of 10 mu m in diameter or being slightly smaller. For smaller spheres the kinetic energy distributions of protons become nonmonotonic, indicating a change in the accelerating mechanism from ambipolar expansion towards a regime dominated by effects caused by Coulomb repulsion of ions. The energy conversion efficiency from laser energy to proton kinetic energy is optimized when the target diameter matches the laser focal spot size with efficiencies reaching the percent level. The change of proton acceleration efficiency with target size can be attributed to the reduced cross-sectional overlap of subfocus targets with the laser. Reported experimental observations are in line with 3D3V particle in cell simulations. They make use of well-defined targets and point out pathways for future applications and experiments.DFG via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) Transregio SFB TR18NNSA DE-NA0002008Super-MUC pr48meIvo CermakCGC Instruments in design and realization of the Paul trap systemIMPRS-APSLMUexcellent Junior Research FundDAAD|ToIFEEuropean Union's Horizon research and innovation programme 633053Physic

    Economic evaluation strategies in telehealth: obtaining a more holistic valuation of telehealth interventions

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    Telehealth is an emerging area of medical research. Its translation from conception, to research and into practice requires tailored research and economic evaluation methods. Due to their nature telehealth interventions exhibit a number of extra-clinical benefits that are relevant when valuing their costs and outcomes. By incorporating methods to measure societal values such as patient preference and willingness-to-pay, a more holistic value can be placed on the extra-clinical outcomes associated with telehealth and evaluations can represent new interventions more effectively. Cost-benefit analysis is a method by which relevant costs and outcomes in telehealth can be succinctly valued and compared. When health economic methods are conducted using holistic approaches such as cost-benefit analysis they can facilitate the translation of telehealth research into policy and practice

    Reducing the SPS Machine Impedance

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    The SPS as LHC Injector project has been working for some time to prepare the SPS for its role as final injector for the LHC. This included major work related to injection, acceleration, extraction and beam instrumentation for the LHC beams [1]. Measurements carried out with the high brightness LHC beam showed that a major improvement of the machine impedance would also be necessary [2]. In addition to removing all lepton related components (once LEP operation ended in 2000), the decision was made to shield the vacuum system pumping port cavities. These accidental cavities had been identified as having characteristic frequencies in the 1-1.5GHz range. Since the SPS vacuum system contains roughly 1000 of these cavities, they constitute a major fraction of the machine impedance. As removal of the ports and associated bellows is not possible, transition shields (PPS) had to be designed to insert within the pumping port cavities

    Industrial work placement in higher education: a study of civil engineering student engagement

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    For civil engineering undergraduates, the opportunity to spend a period of time in formal industrial work placement provides an invaluable learning experience. This paper reviews student engagement with short-term industrial placement and provides analysis of questionnaires (n=174) returned by undergraduates studying civil engineering at four Higher Education Institutes (HEI’s) in the West of Scotland. The data captures industrial placement statistics, employability skill-sets and presents brief testimonies from students. Whilst the journey to becoming a professional civil engineer is undoubtedly enhanced by short-term placement clear opportunities exist for HEI’s to affect and change existing pedagogical discourse. Commentary is likely to resonate beyond civil engineering and serve as a timely reminder of the need to re-invigorate academia / industry curriculum partnerships

    Structure-based design and synthesis of antiparasitic pyrrolopyrimidines targeting pteridine reductase 1

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    The treatment of Human African Trypanosomiasis remains a major unmet health need in sub-Saharan Africa. Approaches involving new molecular targets are important and pteridine reductase 1 (PTR1), an enzyme that reduces dihydrobiopterin in Trypanosoma spp. has been identified as a candidate target and it has been shown previously that substituted pyrrolo[2,3-d]pyrimidines are inhibitors of PTR1 from T. brucei (J. Med. Chem. 2010, 53, 221-229). In this study, 61 new pyrrolo[2,3-d]pyrimidines have been prepared, designed with input from new crystal structures of 23 of these compounds complexed with PTR1, and evaluated in screens for enzyme inhibitory activity against PTR1 and in vitro antitrypanosomal activity. 8 compounds were sufficiently active in both screens to take forward to in vivo evaluation. Thus although evidence for trypanocidal activity in a stage I disease model in mice was obtained, the compounds were too toxic to mice for further development
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