1,051 research outputs found

    Cost-effectiveness of left ventricular assist devices (LVADs) for patients with advanced heart failure : analysis of the British NHS Bridge to Transplant (BTT) program

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    Background: A previous cost-effectiveness analysis showed that bridge to transplant (BTT) with early design left ventricular assist devices (LVADs) for advanced heart failure was more expensive than medical management while appearing less beneficial. Older LVADs were pulsatile, but current second and third generation LVADs are continuous flow pumps. This study aimed to estimate comparative cost-effectiveness of BTT with durable implantable continuous flow LVADs compared to medical management in the British NHS. Methods and results: A semi-Markov multi-state economic model was built using NHS costs data and patient data in the British NHS Blood and Transplant Database (BTDB). Quality-adjusted life years (QALYs) and incremental costs per QALY were calculated for patients receiving LVADs compared to those receiving inotrope supported medical management. LVADs cost £80,569 (127,887)at2011pricesanddeliveredgreaterbenefitthanmedicalmanagement.Theestimatedprobabilisticincrementalcosteffectivenessratio(ICER)was£53,527(127,887) at 2011 prices and delivered greater benefit than medical management. The estimated probabilistic incremental cost-effectiveness ratio (ICER) was £53,527 (84,963)/QALY (95%CI: £31,802–£94,853; 50,47950,479–150,560) (over a lifetime horizon). Estimates were sensitive to choice of comparator population, relative likelihood of receiving a heart transplant, time to transplant, and LVAD costs. Reducing the device cost by 15% decreased the ICER to £50,106 ($79,533)/QALY. Conclusions: Durable implantable continuous flow LVADs deliver greater benefits at higher costs than medical management in Britain. At the current UK threshold of £20,000 to £30,000/QALY LVADs are not cost effective but the ICER now begins to approach that of an intervention for end of life care recently recommended by the British NHS. Cost-effectiveness estimates are hampered by the lack of randomized trials

    Adsorption of para-Hydrogen on Krypton pre-plated graphite

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    Adsorption of para-Hydrogen on the surface of graphite pre-plated with a single layer of atomic krypton is studied thoretically by means of Path Integral Ground State Monte Carlo simulations. We compute energetics and density profiles of para-hydrogen, and determine the structure of the adsorbed film for various coverages. Results show that there are two thermodynamically stable monolayer phases of para-hydrogen, both solid. One is commensurate with the krypton layer, the other is incommensurate. No evidence is seen of a thermodynamically stable liquid phase, at zero temperature. These results are qualitatively similar to what is seen for for para-hydrogen on bare graphite. Quantum exchanges of hydrogen molecules are suppressed in this system.Comment: 12 pages, 6 figures, to appear in the proceedings of "Advances in Computational Many-Body Physics", Banff, Alberta (Canada), January 13-16 200

    Consistent Anisotropic Repulsions for Simple Molecules

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    We extract atom-atom potentials from the effective spherical potentials that suc cessfully model Hugoniot experiments on molecular fluids, e.g., O2O_2 and N2N_2. In the case of O2O_2 the resulting potentials compare very well with the atom-atom potentials used in studies of solid-state propertie s, while for N2N_2 they are considerably softer at short distances. Ground state (T=0K) and room temperatu re calculations performed with the new NNN-N potential resolve the previous discrepancy between experimental and theoretical results.Comment: RevTeX, 5 figure

    Earomyia lonchaeoides (Zetterstedt, 1848) (Diptera, Lonchaeidae) a species and genus new to the Norwegian fauna

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    The lance fly Earomyia lonchaeoides (Zetterstedt, 1848) is reported from Norway representing the first time that not only this species but also this genus has been recorded from the country. E. lonchaeoides is recorded from Viken and Vestfold og Telemark. Comments on biology, distribution, habitat, and identification characters are provided.publishedVersio

    The first records of the pictured-winged fly Homalocephala bimaculata (Wahlberg, 1838) (Diptera, Ulidiidae) from Norway

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    The picture-winged fly Homalocephala bimaculata (Wahlberg, 1838) is reported from Norway for the first time bringing to five the number of species of Homalocephala Zetterstedt, 1838 reported from the country. H. bimaculata is recorded from Hvaler, Viken, and Oslo, Oslo, and, based on numerous and scattered records, the species is considered to be under-recorded due to its secretive lifestyle. The species is regarded as native and, based on the many ovipositioning females observed, reproducing successfully. Comments on biology, distribution, habitat, and identification characters are provided. Keywords: Diptera, Ulidiidae, Homalocephala bimaculata, first record, Norway, biology, distribution.publishedVersio

    A systematic review of the effectiveness and cost-effectiveness of peer education and peer support in prisons.

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    BACKGROUND: Prisoners experience significantly worse health than the general population. This review examines the effectiveness and cost-effectiveness of peer interventions in prison settings. METHODS: A mixed methods systematic review of effectiveness and cost-effectiveness studies, including qualitative and quantitative synthesis was conducted. In addition to grey literature identified and searches of websites, nineteen electronic databases were searched from 1985 to 2012. Study selection criteria were: Population: Prisoners resident in adult prisons and children resident in Young Offender Institutions (YOIs). INTERVENTION: Peer-based interventions Comparators: Review questions 3 and 4 compared peer and professionally led approaches. OUTCOMES: Prisoner health or determinants of health; organisational/ process outcomes; views of prison populations. STUDY DESIGNS: Quantitative, qualitative and mixed method evaluations. RESULTS: Fifty-seven studies were included in the effectiveness review and one study in the cost-effectiveness review; most were of poor methodological quality. Evidence suggested that peer education interventions are effective at reducing risky behaviours, and that peer support services are acceptable within the prison environment and have a positive effect on recipients, practically or emotionally. Consistent evidence from many, predominantly qualitative, studies, suggested that being a peer deliverer was associated with positive effects. There was little evidence on cost-effectiveness of peer-based interventions. CONCLUSIONS: There is consistent evidence from a large number of studies that being a peer worker is associated with positive health; peer support services are also an acceptable source of help within the prison environment and can have a positive effect on recipients. Research into cost-effectiveness is sparse. SYSTEMATIC REVIEW REGISTRATION: PROSPERO ref: CRD42012002349

    Mutations involving the SRY-related gene SOX8 are associated with a spectrum of human reproductive anomalies

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    SOX8 is an HMG-box transcription factor closely related to SRY and SOX9. Deletion of the gene encoding Sox8 in mice causes reproductive dysfunction but the role of SOX8 in humans is unknown. Here, we show that SOX8 is expressed in the somatic cells of the early developing gonad in the human and influences human sex-determination. We identified two individuals with 46,XY disorders/differences in sex development (DSD) and chromosomal rearrangements encompassing the SOX8 locus and a third individual with 46,XY DSD and a missense mutation in the HMG-box of SOX8. In-vitro functional assays indicate that this mutation alters the biological activity of the protein. As an emerging body of evidence suggests that DSDs and infertility can have common etiologies, we also analyzed SOX8 in a cohort of infertile men (n = 274) and two independent cohorts of women with primary ovarian insufficiency (POI; n = 153 and n = 104). SOX8 mutations were found at increased frequency in oligozoospermic men (3.5%; p<0.05) and POI (5.06%; p=4.5x10-5) as compared to fertile/normospermic control populations (0.74%). The mutant proteins identified altered SOX8 biological activity as compared to the wild-type protein. These data demonstrate that SOX8 plays an important role in human reproduction and SOX8 mutations contribute to a spectrum of phenotypes including 46,XY DSD, male infertility and 46,XX POI

    Fusion Energy Output Greater than the Kinetic Energy of an Imploding Shell at the National Ignition Facility

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    A series of cryogenic, layered deuterium-tritium (DT) implosions have produced, for the first time, fusion energy output twice the peak kinetic energy of the imploding shell. These experiments at the National Ignition Facility utilized high density carbon ablators with a three-shock laser pulse (1.5 MJ in 7.5 ns) to irradiate low gas-filled (0.3  mg/cc of helium) bare depleted uranium hohlraums, resulting in a peak hohlraum radiative temperature ∼290  eV. The imploding shell, composed of the nonablated high density carbon and the DT cryogenic layer, is, thus, driven to velocity on the order of 380  km/s resulting in a peak kinetic energy of ∼21  kJ, which once stagnated produced a total DT neutron yield of 1.9×10¹⁶ (shot N170827) corresponding to an output fusion energy of 54 kJ. Time dependent low mode asymmetries that limited further progress of implosions have now been controlled, leading to an increased compression of the hot spot. It resulted in hot spot areal density (ρr∼0.3  g/cm²) and stagnation pressure (∼360  Gbar) never before achieved in a laboratory experiment
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