440 research outputs found
On some phase equilibrium features of charged black holes in flat spacetime via R\'enyi statistics
Motivated by the nonextensive nature of entropy in gravitational context and
the Gauge/Gravity duality, black hole thermodynamics has been attracting
intense emphasis in the literature. Along the present work, we investigate some
features of the phase structure and critical phenomena of the 4-dimensional
charged black holes in asymptotically flat spacetime within the formalism of
R\'enyi statistics. First, we explore the extended phase space via the R\'enyi
statistics approach. Concretely, based on the modified version of the Smarr
formula, we recall the equal-area law to remove the oscillatory non-physical
region in the and planes. Then, the coexistence curves are
determined, as well as the latent heat of phase change. Moreover, we prove that
the critical exponent describing the behavior of the order parameter near the
critical point is , which is consistent with Landau's theory of
continuous phase transition. Lastly, we apply the Hamiltonian approach to
R\'enyi thermodynamics which provides a new and solid mathematical basis for
the extension of phase space and puts more insight into an expected and
profound possible connection between the nonextensivity R\'enyi parameter
and the cosmological constant .Comment: 28 pages, 8 figure
R\'enyi Topology of Charged-flat Black Hole: Hawking-Page and Van-der-Waals Phase Transitions
In this paper, we extend the proposed setup in [1,2] for finding the
topological charges associated with the Hawking-Page and Van-der-Waals
transition points as well as equilibrium phases to catch the nonextensive
nature of the black hole entropy, Rigorously speaking we incorporate the
R\'enyi statistics formalism in off-shell Bragg-Williams free energy landscape
to examine topologically the Hawking-Page phase transition related to the
uncharged/charged-flat black hole in grand canonical and the Van-der- Waals
transition in the canonical ensemble and where a vortex/anti-vortex structure
is found. For this purpose, we introduce three mappings, the - and
-mapping, for phase transitions classification and the -mapping for
equilibrium phases classification. We found that Hawking-Page and Van-der-Waals
phase transitions belong to different topological classes and exhibit an
interplay of total charge values hinting to a possible new correspondence. Our
topological study provides further substantiation for a possible conjecture
positing a correspondence between the thermodynamic characteristics of black
holes in asymptotically flat spacetime using R\'enyi statistics, and those in
asymptotically Anti-de-Sitter spacetime employing Gibbs-Boltzmann statistics.Comment: 37 pages, 18 figures, and 3 table
The effect of local steroid injection on prevertebral soft tissue swelling after anterior cervical discectomy and fusion
BACKGROUND AND OBJECTIVE: Airway obstruction is a lethal complication of anterior cervical discectomy and prevertebral soft tissue swelling after surgery is one the important causes of this complication. The aim of this study is to investigate the effect of local steroid injection on prevertebral soft tissue swelling after anterior cervical discectomy and fusion (ACDF). METHODS: This randomized clinical trial was conducted on 40 patients hospitalized in Qazvin educational & clinical Rajaee hospital who were candidates for ACDF in one to three segments because of myelopathy or radiculopathy. Patients were randomly divided into case and control groups. In case group (20 patients), 80 mg methylprednisolone was injected locally on the site of the operation. No injection was performed in control group (20 patients). Lateral neck radiography was performed one day before surgery and on the second and tenth day after surgery. The ratio of prevertebral soft tissue thickness to mid anteroposterior vertebral body (S/V) was calculated for C3-C7. In addition, pain and dysphagia after surgery were recorded on the second and tenth day after surgery (IRCT:201507212327N1). FINDINGS: S/V ratio in C3-C7 revealed no significant difference in both groups. On the second day after surgery, increase in S/V ratio in all cervical vertebrae revealed a significant difference between the two groups compared with the day before surgery (p<0.001). However, this level of increase on the tenth day was only significant in C5 (control group=0.10±0.07, case group=0.02±0.08) and C7 (control group=0.11±0.05, case group=0.02±0.1) (p=0.004 and p=0.002, respectively). There was also a significant difference between the two groups on the second and tenth day regarding intensity of pain and dysphagia after surgery (p=0.001). CONCLUSION: Based on the results of this study, local methylprednisolone injection reduces prevertebral soft tissue swelling, pain and dysphagia after surgery. © 2016, Babol University of Medical Sciences. All rights reserved
Assessing the Association between Serum Ferritin, Transferrin Saturation, and C-Reactive Protein in Northern Territory Indigenous Australian Patients with High Serum Ferritin on Maintenance Haemodialysis
Copyright © 2017 SandawanaWilliam Majoni et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Objective. To determine the significance of high serum ferritin observed in Indigenous Australian patients on maintenance haemodialysis in the Northern Territory, we assessed the relationship between ferritin and transferrin saturation (TSAT) as measures of iron status and ferritin and C-reactive protein (CRP) as markers of inflammation. Methods. We performed a retrospective cohort analysis of data from adult patients (≥18 years) on maintenance haemodialysis (>3 months) from 2004 to 2011. Results. There were 1568 patients. The mean age was 53.9 (11.9) years. 1244 (79.3%) were Indigenous. 44.2% () were male. Indigenous patients were younger (mean age [52.3 (11.1) versus 57.4 (15.2), ]) and had higher CRP [14.7 mg/l (7–35) versus 5.9 mg/l (1.9–17.5), ], higher median serum ferritin [1069 µg/l (668–1522) versus 794.9 µg/l (558.5–1252.0), ], but similar transferrin saturation [26% (19–37) versus 28% (20–38), ]. We observed a small positive correlation between ferritin and TSAT (, ), no correlation between ferritin and CRP ( = 0.001, ), and positive association between high serum ferritin and TSAT (), Indigenous ethnicity (), urea reduction ratio (), and gender () after adjustment in mixed regression analysis. Conclusion. Serum ferritin and TSAT may inadequately reflect iron status in this population. The high ferritin was poorly explained by inflammation
High Energy & High Luminosity Colliders
With the best of modern standard lasers, high-energy colliders
from electron beams of E larger than 250 GeV are only possible at the expense
of photon luminosity, i.e. 10 times lower than for photon colliders at c.m.
energies below 0.5 TeV. For existing state-of-the art lasers, an optimistic
upper energy limit for x=4.8 is an electron beam of less than 250 GeV. This
Snowmass21 Contributed Paper shows how Free Electron Lasers (FEL) pave the way
for High Energy & High Luminosity colliders. We present and
assess a conceptual design study of a FEL with wavelength of 2.4 m and an
x-factor in the range of 2 to 40, to maximize the luminosity of a
collider as second interaction region of 0.5 TeV to 10 TeV c.m.
colliders.Comment: Contribution to Snowmass 202
Ptch2/Gas1 and Ptch1/Boc differentially regulate Hedgehog signalling in murine primordial germ cell migration.
Gas1 and Boc/Cdon act as co-receptors in the vertebrate Hedgehog signalling pathway, but the nature of their interaction with the primary Ptch1/2 receptors remains unclear. Here we demonstrate, using primordial germ cell migration in mouse as a developmental model, that specific hetero-complexes of Ptch2/Gas1 and Ptch1/Boc mediate the process of Smo de-repression with different kinetics, through distinct modes of Hedgehog ligand reception. Moreover, Ptch2-mediated Hedgehog signalling induces the phosphorylation of Creb and Src proteins in parallel to Gli induction, identifying a previously unknown Ptch2-specific signal pathway. We propose that although Ptch1 and Ptch2 functionally overlap in the sequestration of Smo, the spatiotemporal expression of Boc and Gas1 may determine the outcome of Hedgehog signalling through compartmentalisation and modulation of Smo-downstream signalling. Our study identifies the existence of a divergent Hedgehog signal pathway mediated by Ptch2 and provides a mechanism for differential interpretation of Hedgehog signalling in the germ cell niche
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