2,202 research outputs found

    Radiation and Potential Barriers of a 5D Black String Solution

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    By using a massless scalar field we examine the effect of an extra dimension on black hole radiation. Because the equations are coupled, we find that the structure of the fifth dimension (as for membrane and induced-matter theory) affects the nature of the radiation observed in four-dimensional spacetime. In the case of the Schwarzschild-de Sitter solution embedded in a Randall-Sundrum brane model, the extension of the black hole along the fifth dimension looks like a black string. Then it is shown that, on the brane, the potential barrier surrounding the black hole has a quantized as well as a continuous spectrum. In principle, Hawking radiation may thus provide a probe for higher dimensions.Comment: 9 pages, 3 figures, accepted for publication on MPL

    Reduction of Landing Gear Noise using Meshes

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    Spectrums of Black Hole in de Sitter Spacetime with Highly Damped Quasinormal Modes: High Overtone Case

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    Motivated by recent physical interpretation on quasinormal modes presented by Maggiore, the adiabatic quantity method given by Kunstatter is used to calculate the spectrums of a non-extremal Schwarzschild de Sitter black hole in this paper, as well as electrically charged case. According to highly damped Konoplya and Zhidenko's numerical observational results for high overtone modes\cite{Konoplya}, we found that the asymptotic non-flat spacetime structure leads two interesting facts as followings: (i) near inner event horizon, the area and entropy spectrums, which are given by Aen=8n1πA_{en} = 8 n_1 \pi \hbar, Sen=2πn1S_{en} = 2\pi n_1\hbar, are equally spaced accurately. (ii) However, near outer cosmological horizon the spectrums, which are in the form of Acn=16n2π48πΛAcn3Acn2A_{cn} = 16 n_2 \pi \hbar - \sqrt{\frac{48\pi}{\Lambda}A_{cn} - 3 A_{cn}^2}, Scn=4πn23πΛAcn3/16Acn2S_{cn} = 4 \pi n_2 \hbar - \sqrt{\frac{3\pi}{\Lambda}A_{cn} - 3/16 A_{cn}^2}, are not markedly equidistant. Finally, we also discuss the electrically charged case and find the black holes in de Sitter spacetime have similar quantization behavior no matter with or without charge.Comment: 12 pages, 2 firures, published versio

    Quality improvement interventions to prevent the use of hospital services among nursing home residents: protocol for a systematic review and meta-analysis

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    Introduction: Quality improvement interventions are a promising strategy for reducing hospital services use among nursing home residents. However, evidence for their effectiveness is limited. It is unclear which characteristics of the quality improvement intervention and activities planned to facilitate implementation may promote fidelity to organisational and system changes. This systematic review and meta-analysis will assess the effectiveness of quality improvement interventions and implementation strategies aimed at reducing hospital services use among nursing home residents. Methods and analysis: The MEDLINE, CINAHL, Cochrane Library, Embase and Web of Science databases will be comprehensively searched in September 2023. The eligible studies should focus on the implementation of a quality improvement intervention defined as the systematic, continuous approach that designs, tests and implements changes using real-time measurement to reduce hospitalisations or emergency department visits among long-stay nursing home residents. Quality improvement details and implementation strategies will be deductively categorised into effective practice and organisation of care taxonomy domains for delivery arrangements and implementation strategies. Quality and bias assessments will be completed using the Quality Improvement Minimum Quality Criteria Set and the Joanna Briggs Institute Critical Appraisal Tools.The results will be pooled in a meta-analysis, by combining the natural logarithms of the rate ratios across the studies or by calculating the rate ratio using the generic inverse-variance method. Heterogeneity will be assessed using the I2 or H2 statistics if the number of included studies will be less than 10. Raw data will be requested from the authors, as required. Ethics and dissemination: Ethical approval is not required. The results will be published in a peer-review journal and presented at (inter)national conferences. Prospero registration number: CRD42022364195

    156 Adaptive metabolic changes in Pseudomonas aeruginosa during cystic fibrosis lung infection

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    The influence of quintessence on the motion of a binary system in cosmology

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    We employ the metric of Schwarzschild space surrounded by quintessential matter to study the trajectories of test masses on the motion of a binary system. The results, which are obtained through the gradually approximate approach, can be used to search for dark energy via the difference of the azimuth angle of the pericenter. The classification of the motion is discussed.Comment: 7 pages, 1 figur

    Efficacy and safety of topical delgocitinib in patients with chronic hand eczema: data from a randomized, double‐blind, vehicle‐controlled phase II a study

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    Background: Management of chronic hand eczema (CHE) remains a challenge; effective topical treatment is limited to corticosteroids. Objectives: To assess the efficacy and safety of a novel, pan-Janus kinase inhibitor (delgocitinib) in patients with CHE. Methods: In this randomized, double-blind, phase IIa study, patients with CHE received delgocitinib ointment 30 mg g(-1) or vehicle ointment for 8 weeks. The primary end point was the proportion of patients achieving treatment success ['clear'/'almost clear' skin with ≥ 2-point improvement in the Physician's Global Assessment of disease severity (PGA)] at week 8. Secondary end points included Hand Eczema Severity Index (HECSI) score changes and the proportion of patients achieving treatment success on the Patient's Global Assessment of disease severity (PaGA). Results: Ninety-one patients were randomized. More patients receiving delgocitinib (46%) than vehicle (15%) [odds ratio 4 center dot 89, 95% confidence interval (CI) 1 center dot 49-16 center dot 09; P = 0 center dot 009] achieved treatment success (PGA). Adjusted mean HECSI score at week 8 was lower with delgocitinib (13 center dot 0) than with vehicle (25 center dot 8) (adjusted mean difference -12 center dot 88, 95% CI -21 center dot 47 to -4 center dot 30; P = 0 center dot 003). More patients receiving delgocitinib than vehicle achieved treatment success by PaGA, but this did not reach statistical significance. The incidence of adverse events was similar with delgocitinib and vehicle; none led to discontinuation of delgocitinib. Conclusions: Delgocitinib ointment was efficacious and well tolerated. As a plateau of efficacy was not observed, a longer treatment period may lead to increased efficacy. Further clinical studies are warranted to confirm these findings in patients with CHE

    Quantum Statistical Entropy and Minimal Length of 5D Ricci-flat Black String with Generalized Uncertainty Principle

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    In this paper, we study the quantum statistical entropy in a 5D Ricci-flat black string solution, which contains a 4D Schwarzschild-de Sitter black hole on the brane, by using the improved thin-layer method with the generalized uncertainty principle. The entropy is the linear sum of the areas of the event horizon and the cosmological horizon without any cut-off and any constraint on the bulk's configuration rather than the usual uncertainty principle. The system's density of state and free energy are convergent in the neighborhood of horizon. The small-mass approximation is determined by the asymptotic behavior of metric function near horizons. Meanwhile, we obtain the minimal length of the position Δx\Delta x which is restrained by the surface gravities and the thickness of layer near horizons.Comment: 11pages and this work is dedicated to the memory of Professor Hongya Li
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