2,664 research outputs found
Radiation and Potential Barriers of a 5D Black String Solution
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
Spectrums of Black Hole in de Sitter Spacetime with Highly Damped Quasinormal Modes: High Overtone Case
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 ,
, are equally spaced accurately. (ii) However, near
outer cosmological horizon the spectrums, which are in the form of , , 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
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
The influence of quintessence on the motion of a binary system in cosmology
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
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
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 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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