6,057 research outputs found

    Religious leaders\u27 perceptions of advance care planning: a secondary analysis of interviews with Buddhist, Christian, Hindu, Islamic, Jewish, Sikh and Bahai leaders

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    Background: International guidance for advance care planning (ACP) supports the integration of spiritual and religious aspects of care within the planning process. Religious leaders’ perspectives could improve how ACP programs respect patients’ faith backgrounds. This study aimed to examine: (i) how religious leaders understand and consider ACP and its implications, including (ii) how religion affects followers’ approaches to end-of-life care and ACP, and (iii) their implications for healthcare. Methods: Interview transcripts from a primary qualitative study conducted with religious leaders to inform an ACP website, ACPTalk, were used as data in this study. ACPTalk aims to assist health professionals conduct sensitive conversations with people from different religious backgrounds. A qualitative secondary analysis conducted on the interview transcripts focussed on religious leaders’ statements related to this study’s aims. Interview transcripts were thematically analysed using an inductive, comparative, and cyclical procedure informed by grounded theory. Results: Thirty-five religious leaders (26 male; mean 58.6-years-old), from eight Christian and six non-Christian (Jewish, Buddhist, Islamic, Hindu, Sikh, Bahá’í) backgrounds were included. Three themes emerged which focussed on: religious leaders’ ACP understanding and experiences; explanations for religious followers’ approaches towards end-of-life care; and health professionals’ need to enquire about how religion matters. Most leaders had some understanding of ACP and, once fully comprehended, most held ACP in positive regard. Religious followers’ preferences for end-of-life care reflected family and geographical origins, cultural traditions, personal attitudes, and religiosity and faith interpretations. Implications for healthcare included the importance of avoiding generalisations and openness to individualised and/ or standardised religious expressions of one’s religion. Conclusions: Knowledge of religious beliefs and values around death and dying could be useful in preparing health professionals for ACP with patients from different religions but equally important is avoidance of assumptions. Community-based initiatives, programs and faith settin

    Enhancement of perfluorooctanoate and perfluorooctanesulfonate activity at acoustic cavitation bubble interfaces

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    Acoustic cavitation driven by ultrasonic irradiation decomposes and mineralizes the recalcitrant perfluorinated surfactants perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA). Pyrolytic cleavage of the ionic headgroup is the rate-determining step. In this study, we examine the sonochemical adsorption of PFOX, where X = S for PFOS and A for PFOA, by determining kinetic order and absolute rates over an initial PFOX concentration range of 20 nM to 200 ÎŒM. Sonochemical PFOX kinetics transition from pseudo-first-order at low initial concentrations, [PFOX]_i 40 ÎŒM, as the bubble interface sites are saturated. At PFOX concentrations below 100 ÎŒM, concentration-dependent rates were modeled with Langmuir−Hinshelwood (LH) kinetics. Empirically determined rate maximums, V_(Max)^(−PFOA) = 2230 ± 560 nM min^−1 and V_(Max)^(−PFOS) = 230 ± 60 nM min^−1, were used in the LH model, and sonochemical surface activities were estimated to be K_(Sono)^(PFOS) = 120000 M^−1 and K_(Sono)^(PFOA) = 28500 M^−1, 60 and 80 times greater than equilibrium surface activities, K_(Eq)^(PFOS) and K_(Eq)^(PFOA). These results suggest enhanced sonochemical degradation rates for PFOX when the bubble interface is undersaturated. The present results are compared to previously reported sonochemical kinetics of nonvolatile surfactants

    Hydrodynamic lift of vesicles under shear flow in microgravity

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    The dynamics of a vesicle suspension in a shear flow between parallel plates has been investigated under microgravity conditions, where vesicles are only submitted to hydrodynamic effects such as lift forces due to the presence of walls and drag forces. The temporal evolution of the spatial distribution of the vesicles has been recorded thanks to digital holographic microscopy, during parabolic flights and under normal gravity conditions. The collected data demonstrates that vesicles are pushed away from the walls with a lift velocity proportional to γ˙R3/z2\dot{\gamma} R^3/z^2 where γ˙\dot{\gamma} is the shear rate, RR the vesicle radius and zz its distance from the wall. This scaling as well as the dependence of the lift velocity upon vesicle aspect ratio are consistent with theoretical predictions by Olla [J. Phys. II France {\bf 7}, 1533--1540 (1997)].Comment: 6 pages, 8 figure

    Abrupt grain boundary melting in ice

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    The effect of impurities on the grain boundary melting of ice is investigated through an extension of Derjaguin-Landau-Verwey-Overbeek theory, in which we include retarded potential effects in a calculation of the full frequency dependent van der Waals and Coulombic interactions within a grain boundary. At high dopant concentrations the classical solutal effect dominates the melting behavior. However, depending on the amount of impurity and the surface charge density, as temperature decreases, the attractive tail of the dispersion force interaction begins to compete effectively with the repulsive screened Coulomb interaction. This leads to a film-thickness/temperature curve that changes depending on the relative strengths of these interactions and exhibits a decrease in the film thickness with increasing impurity level. More striking is the fact that at very large film thicknesses, the repulsive Coulomb interaction can be effectively screened leading to an abrupt reduction to zero film thickness.Comment: 8 pages, 1 figur

    Dynamics of explosive degassing of magma: Observations of fragmenting two-phase flows

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    Liquid explosions, generated by rapid degassing of strongly supersaturated liquids, have been investigated in the laboratory with a view to understanding the basic physical processes operating during bubble nucleation and growth and the subsequent behavior of the expanding two-phase flow. Experiments are carried out in a shock tube and are monitored by high-speed photography and pressure transducers. Theoretical CO_2 supersaturations up to 455 times the ambient saturation concentration are generated by a chemical reaction; K_2CO_3 solution is suddenly injected into an excess of HCl solution in such a way as to mix the two solutions rapidly. Immediately after the injection event, a bubble nucleation delay of a few milliseconds is followed by rapid nucleation and explosive expansion of CO_2 bubbles forming a highly heterogeneous foam. Enhanced diffusion due to advection in the flow coupled with continuous mixing of the reactants, and hence on-going bubble nucleation after injection, generates an increasingly accelerating flow until the reactants become depleted at peak accelerations of around 150 g and velocities of about 15 m s^(−1). Stretching of the accelerating two-phase mixture enhances the mixing. Liberation of CO_2 vapor is spatially inhomogeneous leading to ductile fragmentation occurring throughout the flow in regions of greatest gas release as the consequence of the collision and stretching of fluid streams. The violence of the eruptions is controlled by using different concentrations of the HCl and K_2CO_3 solutions, which alters the CO_2 supersaturation and yield and also the efficiency of the mixing process. Peak acceleration is proportional to theoretical supersaturation. Pressure measurements at the base of the shock tube show an initial nucleation delay and a pressure pulse related to the onset of explosive bubble formation. These chemically induced explosions differ from liquid explosions created in other experiments. In explosions caused by sudden depressurization of CO_2-saturated water, the bubbles nucleate uniformly throughout the liquid in a single nucleation event. Subsequent bubble growth causes the two-phase mixture to be accelerated upward at nearly constant accelerations. Explosively boiling liquids, in which heterogeneous nucleation is suppressed, experience an evaporation wave which propagates down into the liquid column at constant average velocity. Fragmentation occurs at the sharply defined leading edge of the wavefront. The chemical flows effectively simulate highly explosive volcanic eruptions as they are comparable in terms of flow densities, velocities, accelerations, and in the large range of scales present. The large accelerations cause strong extensional strain and longitudinal deformation. Comparable deformation rates in volcanic systems could be sufficient to approach conditions for brittle fragmentation. Tube pumice is a major component of plinian deposits and ignimbrites and preserves evidence of accelerating flow conditions

    Generalized Interpolation Material Point Approach to High Melting Explosive with Cavities Under Shock

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    Criterion for contacting is critically important for the Generalized Interpolation Material Point(GIMP) method. We present an improved criterion by adding a switching function. With the method dynamical response of high melting explosive(HMX) with cavities under shock is investigated. The physical model used in the present work is an elastic-to-plastic and thermal-dynamical model with Mie-Gr\"uneissen equation of state. We mainly concern the influence of various parameters, including the impacting velocity vv, cavity size RR, etc, to the dynamical and thermodynamical behaviors of the material. For the colliding of two bodies with a cavity in each, a secondary impacting is observed. Correspondingly, the separation distance DD of the two bodies has a maximum value Dmax⁥D_{\max} in between the initial and second impacts. When the initial impacting velocity vv is not large enough, the cavity collapses in a nearly symmetric fashion, the maximum separation distance Dmax⁥D_{\max} increases with vv. When the initial shock wave is strong enough to collapse the cavity asymmetrically along the shock direction, the variation of Dmax⁥D_{\max} with vv does not show monotonic behavior. Our numerical results show clear indication that the existence of cavities in explosive helps the creation of ``hot spots''.Comment: Figs.2,4,7,11 in JPG format; Accepted for publication in J. Phys. D: Applied Physic

    The Association of Early Dietary Supplementation with Vitamin E with the Incidence of Ulcerative Dermatitis in Mice on a C57BL/6 Background

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    The purpose of this study was to ascertain if prophylactic ingestion of a diet rich in vitamin E would prevent  or impede the development of ulcerative dermatitis in mice on a C57BL/6 background. Mice were fed after  weaning a standard mouse diet, vitamin E (99 IU/kg), or a mouse diet fortified with vitamin E (3000 IU/  kg). Cases of ulcerative dermatitis were recorded by individuals (i.e. aware of) the diet assignment. The  incidence of ulcerative dermatitis in a retrospective cohort of mice on standard diet was compared with the  group on the diet fortified with vitamin E. Age was associated with ulcerative dermatitis in standard diet  and vitamin E fortified diet groups, r = 0.43, p-value < 0.0001 and r = 0.18, p-value < 0.02, respectively.  The average age of incidence for ulcerative dermatitis in the mice fed the standard diet was 89 weeks and  for the mice fed the vitamin E diet it was 41 weeks. The unadjusted odds ratio comparing the incidence of  ulcerative dermatitis between the two diet groups was 4.6 with a 95% confidence interval of (2.44, 8.58),  x2 p-value < 0.0001. Therefore, there was an association between the diets and ulcerative dermatitis, with  the mice on the vitamin E fortified diet having almost five times the odds of having ulcerative dermatitis  compared with mice on the standard diet. Incidence of ulcerative dermatitis was not influenced by sex or  genotype. Our study results show that a diet fortified in vitamin E initiated at weaning does not prevent or  impede the development of ulcerative dermatitis in mice on a C57BL/6 background and on the contrary  accelerate development when administered to young mice.

    Solution processed amorphous silicon surface passivation layers

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    Amorphous silicon thin films, fabricated by thermal conversion of neopentasilane, were used to passivate crystalline silicon surfaces. The conversion is investigated using X ray and constant final state yield photoelectron spectroscopy, and minority charge carrier lifetime spectroscopy. Liquid processed amorphous silicon exhibits high Urbach energies from 90 to 120 meV and 200 meV lower optical band gaps than material prepared by plasma enhanced chemical vapor deposition. Applying a hydrogen plasma treatment, a minority charge carrier lifetime of 1.37 ms at an injection level of 1015 cm3 enabling an implied open circuit voltage of 724 mV was achieved, demonstrating excellent silicon surface passivatio

    The three-dimensional Ising model: A paradigm of liquid-vapor coexistence in nuclear multifragmentation

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    Clusters in the three-dimensional Ising model rigorously obey reducibility and thermal scaling up to the critical temperature. The barriers extracted from Arrhenius plots depend on the cluster size as B∝AσB \propto A^{\sigma} where σ\sigma is a critical exponent relating the cluster size to the cluster surface. All the Arrhenius plots collapse into a single Fisher-like scaling function indicating liquid-vapor-like phase coexistence and the univariant equilibrium between percolating clusters and finite clusters. The compelling similarity with nuclear multifragmentation is discussed.Comment: (4 pages, 4 figures
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