1,025 research outputs found

    PIH20 What Really Matters? A Multi-View Perspective of One Patient's Hospital Experience

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    ObjectivesTo identify what mattered to a patient and family member (health care recipients) during the patient’s hospital experience and to examine the health care provider’s awareness of what mattered to the recipients.MethodsA qualitative descriptive investigation was undertaken using semi-structured interviews designed to compare multiple perceptions of one patient’s hospital experience. Interviews were undertaken with the patient (post-surgical procedure), family member, and health care providers whom the patient identified as impacting the hospital experience. Interviews were audio recorded and transcribed. A definition of hospital experience was sought from each participant. Additional phrases as presented by the patient and family member were coded and grouped into categories and then salient themes. Phrases as presented by the health care providers were coded, and then allocated to the previously identified themes.ResultsOne patient, his wife and seven health care providers (doctors (2), registered nurses (4) and a patient care orderly (1)) were interviewed. Definitions of what constitutes ‘hospital experience’ differ between the participants. Recipients of care include pre and post hospital admission periods, whereas providers limit hospital experience to admission. Three salient themes emerged from recipient data suggesting; medication management, physical comfort and emotional security are what mattered. Awareness of the significance of these factors differed between the providers and was theme dependent.ConclusionsHospital experience as a term is poorly defined, and definitions differ between recipients and providers of care. Health care providers are not always aware of what matters to the patient and family during their hospital admission

    Solar-driven semi-conductor photocatalytic water treatment (TiO2, g-C3N4, and TiO2+g-C3N4) of cyanotoxins: proof-of-concept study with microcystin-LR.

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    Cyanobacteria and their toxins are a threat to drinking water safety as increasingly cyanobacterial blooms (mass occurrences) occur in lakes and reservoirs all over the world. Photocatalytic removal of cyanotoxins by solar light active catalysts is a promising way to purify water at relatively low cost compared to modifying existing infrastructure. We have established a facile and low-cost method to obtain TiO2 and g-C3N4 coated floating photocatalysts using recycled glass beads. g-C3N4 coated and TiO2+g-C3N4 co-coated beads were able to completely remove microcystin-LR in artificial fresh water under both natural and simulated solar light irradiation without agitation in less than 2 h. TiO2 coated beads achieved complete removal within 8 h of irradiation. TiO2+g-C3N4 beads were more effective than g-C3N4 beads as demonstrated by the increase reaction rate with reaction constants, 0.0485 min−1 compared to 0.0264 min−1 respectively, with TiO2 alone found to be considerably slower 0.0072 min−1. g-C3N4 based photocatalysts showed a similar degradation pathway to TiO2 based photocatalysts by attacking the C6–C7 double bond on the Adda side chain

    Heavy Quarks on Anisotropic Lattices: The Charmonium Spectrum

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    We present results for the mass spectrum of ccˉc{\bar c} mesons simulated on anisotropic lattices where the temporal spacing ata_t is only half of the spatial spacing asa_s. The lattice QCD action is the Wilson gauge action plus the clover-improved Wilson fermion action. The two clover coefficients on an anisotropic lattice are estimated using mean links in Landau gauge. The bare velocity of light νt\nu_t has been tuned to keep the anisotropic, heavy-quark Wilson action relativistic. Local meson operators and three box sources are used in obtaining clear statistics for the lowest lying and first excited charmonium states of 1S0^1S_0, 3S1^3S_1, 1P1^1P_1, 3P0^3P_0 and 3P1^3P_1. The continuum limit is discussed by extrapolating from quenched simulations at four lattice spacings in the range 0.1 - 0.3 fm. Results are compared with the observed values in nature and other lattice approaches. Finite volume effects and dispersion relations are checked.Comment: 36 pages, 6 figur

    Spin glass behavior of frustrated 2-D Penrose lattice in the classical planar model

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    Via extensive Monte Carlo studies we show that the frustrated XY Hamiltonian on a 2-D Penrose lattice admits of a spin glass phase at low temperature. Studies of the Edwards-Anderson order parameter, spin glass susceptibility, and local (linear) susceptibility point unequivocally to a paramagnetic to spin glass transition as the temperature is lowered. Specific heat shows a rounded peak at a temperature above the spin glass transition temperature, as is commonly observed in spin glasses. Our results strongly suggest that the critical point exponents are the same as obtained by Bhatt and Young in the ±J{\pm}J Ising model on a square lattice. However, unlike in the latter case, the critical temperature is clearly finite (nonzero). The results imply that a quasiperiodic 2-D array of superconducting grains in a suitably chosen transverse magnetic field should behave as a superconducting glass at low temperature.Comment: RevTex, 4 pages Including 4 figures. To appear in the June 1 1996 issue of Phys. Rev. B (Rapid Communications). Revised/replaced edition contains an erratum at the end of the paper, also to appear in Phys. Rev.

    Cathodoluminescence studies of GaN coalesced from nanopyramids selectively grown by MOVPE

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    Coalescence of GaN over arrays of GaN nanopyramids has important device applications and has been achieved on nano-imprint lithographically patterned GaN/sapphire substrates using metal organic vapour phase epitaxy. Spatially and spectrally resolved cathdoluminescence (CL) from such coalesced layers are studied in detail. The observed redshift of the GaN band edge emission with increasing electron beam depth of maximum CL into the coalesced layer is discussed in relation to a carrier-induced peak shift, likely due to Si out-diffusion from the mask material into the GaN. Depth-resolved CL measurements are used to quantify the redshift in terms of bandgap renormalization and strain effects. CL maps showing the GaN near band edge peak energy distribution reveal micron-scale domain-like variations in peak energy and are attributed to the effects of local strain

    Caretaker mental health and family environment factors are associated with adolescent psychiatric problems in a Vietnamese sample

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    Little is known about risk factors for adolescent mental health in Vietnam. The present study investigated the relationship between caretaker mental health and adolescent mental health in a cross-sectional Vietnamese sample. Primary caretakers completed measures of their own mental distress and general health status using the Self-Reporting Questionnaire-20 (SRQ-20) as well as reports of adolescent mental health using the parent version of the Strengths and Difficulties Questionnaire (SDQ). Multivariate regression models were used to examine the relationships between the caretaker and adolescent health variables. The demographic factors of age, sex, ethnicity, religious affiliation, and household wealth status demonstrated significant relationships with SDQ subscale scores. Caretaker mental health was positively associated with adolescent mental health, and this association remained significant even after accounting for other relevant demographic variables and caretaker general health status. Understanding correlates of adolescent mental health difficulties may help identify youth and families at risk for developing psychiatric problems and inform mental health interventions in Vietnam

    Photocatalytic removal of the cyanobacterium Microcystis aeruginosa PCC7813 and four microcystins by TiO2 coated porous glass beads with UV-LED irradiation.

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    Cyanobacteria and their toxic secondary metabolites are a challenge in water treatment due to increased biomass and dissolved metabolites in the raw water. Retrofitting existing water treatment infrastructure is prohibitively expensive or unfeasible, hence 'in-reservoir' treatment options are being explored. In the current study, a treatment system was able to photocatalytically inhibit the growth of Microcystis aeruginosa and remove released microcystins by photocatalysis using titanium dioxide coated, porous foamed glass beads and UV-LEDs (365 nm). A 35% reduction of M. aeruginosa PCC7813 cell density compared to control samples was achieved in seven days. As a function of cell removal, intracellular microcystins (microcystin-LR, -LY, -LW and -LF) were removed by 49% from 0.69 to 0.35 μg mL−1 in seven days. Microcystins that leaked into the surrounding water from compromised cells were completely removed by photocatalysis. The findings of the current study demonstrate the feasibility of an in-reservoir treatment unit applying low cost UV-LEDs and porous foamed beads made from recycled glass coated with titanium dioxide as a means to control cyanobacteria and their toxins before they can reach the water treatment plant

    Dynamic renormalization group study of a generalized continuum model of crystalline surfaces

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    We apply the Nozieres-Gallet dynamic renormalization group (RG) scheme to a continuum equilibrium model of a d-dimensional surface relaxing by linear surface tension and linear surface diffusion, and which is subject to a lattice potential favoring discrete values of the height variable. The model thus interpolates between the overdamped sine-Gordon model and a related continuum model of crystalline tensionless surfaces. The RG flow predicts the existence of an equilibrium roughening transition only for d = 2 dimensional surfaces, between a flat low-temperature phase and a rough high-temperature phase in the Edwards-Wilkinson (EW) universality class. The surface is always in the flat phase for any other substrate dimensions d > 2. For any value of d, the linear surface diffusion mechanism is an irrelevant perturbation of the linear surface tension mechanism, but may induce long crossovers within which the scaling properties of the linear molecular-beam epitaxy equation are observed, thus increasing the value of the sine-Gordon roughening temperature. This phenomenon originates in the non-linear lattice potential, and is seen to occur even in the absence of a bare surface tension term. An important consequence of this is that a crystalline tensionless surface is asymptotically described at high temperatures by the EW universality class.Comment: 22 pages, 5 figures. Accepted for publication in Physical Review

    A paradigm-shift in water treatment: in-reservoir UV-LED-driven TiO2 photocatalysis for the removal of cyanobacteria: a mesocosm study.

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    Potentially harmful cyanobacteria challenge potable water treatment globally, with high biomass events, and dissolved toxic and nuisance metabolites. Retrofitting existing water treatment infrastructure is often impractical (if not impossible) and often prohibitively expensive. In a paradigm-shifting move, we propose in-reservoir pre-treatment of cyanobacteria-contaminated raw waters to ease the burden on existing water treatment infrastructure. In an iterative design approach over three years, treatment modules have been designed, refined and optimised, in bench and pilot-scale studies for in-reservoir deployment. TiO2-coated beads made from recycled glass are employed in conjunction with UV-light emitting diodes (LEDs), to create highly reactive hydroxyl radicals that preferably remove cyanobacteria and subsequently released cyanotoxins from raw water. In a mesocosm study using a drinking water reservoir in Brazil, water quality parameters were markedly improved within 72h of deployment and cyanobacterial presence was decreased by over 90% without affecting other phytoplankton communities. The treatment system is virtually plastic-free, low cost, utilises recycled materials and could ultimately be powered by renewable energies, thus providing a true green treatment option. We have conclusively demonstrated that a paradigm-shift towards in-reservoir treatment is not only possible but feasible and can provide a valuable addition to conventional water treatment methods

    Screening of Hydrodynamic Interactions in Semidilute Polymer Solutions: A Computer Simulation Study

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    We study single-chain motion in semidilute solutions of polymers of length N = 1000 with excluded-volume and hydrodynamic interactions by a novel algorithm. The crossover length of the transition from Zimm (short lengths and times) to Rouse dynamics (larger scales) is proportional to the static screening length. The crossover time is the corresponding Zimm time. Our data indicate Zimm behavior at large lengths but short times. There is no hydrodynamic screening until the chains feel constraints, after which they resist the flow: "Incomplete screening" occurs in the time domain.Comment: 3 figure
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