14 research outputs found
Thermodynamics of string black hole with hyperscaling violation
In this paper, we start with black brane and construct specific space-time
which violates hyperscaling. In order to obtain the string solution we apply
Null-Melvin-Twist and -reduction. By using the difference action method we
study thermodynamics of system to obtain Hawking-Page phase transition. In
order to have hyperscaling violation we need to consider
In that case the free energy is always negative and our solution is thermal
radiation without a black hole. Therefore we find that there is not any
Hawking-Page transition. Also, we discuss the stability of system and all
thermodynamical quantities.Comment: 12 pages. Accepted for publication in EPJ
Schr\"odinger Holography with and without Hyperscaling Violation
We study the properties of the Schr\"odinger-type non-relativistic holography
for general dynamical exponent z with and without hyperscaling violation
exponent \theta. The scalar correlation function has a more general form due to
general z as well as the presence of \theta, whose effects also modify the
scaling dimension of the scalar operator. We propose a prescription for minimal
surfaces of this "codimension 2 holography," and demonstrate the (d-1)
dimensional area law for the entanglement entropy from (d+3) dimensional
Schr\"odinger backgrounds. Surprisingly, the area law is violated for d+1 < z <
d+2, even without hyperscaling violation, which interpolates between the
logarithmic violation and extensive volume dependence of entanglement entropy.
Similar violations are also found in the presence of the hyperscaling
violation. Their dual field theories are expected to have novel phases for the
parameter range, including Fermi surface. We also analyze string theory
embeddings using non-relativistic branes.Comment: 62 pages and 6 figures, v2: several typos in section 5 corrected,
references added, v3: typos corrected, references added, published versio
The Dynamical Structure and Evolution of Giant Molecular Clouds
Giant molecular clouds (GMCs) are the sites of star formation in the Galaxy. Many of their properties can be understood in terms of a model in which the GMCs and the star-forming clumps within them are in approximate pressure equilibrium, with turbulent motions treated as a separate pressure component
A review of economic evaluation models for cardiac resynchronization therapy with implantable cardioverter defibrillators in patients with heart failure
Objectives
Cardiac resynchronization therapy with a biventricular pacemaker (CRT-P) is an effective treatment for dyssynchronous heart failure (DHF). Adding an implantable cardioverter defibrillator (CRT-D) may further reduce the risk of sudden cardiac death (SCD). However, if the majority of patients do not require shock therapy, the cost-effectiveness ratio of CRT-D compared to CRT-P may be high. The objective of this study was to systematically review decision models evaluating the cost-effectiveness of CRT-D for patients with DHF, compare the structure and inputs of these models and identify the main factors influencing the ICERs for CRT-D.
Methods
A comprehensive search strategy of Medline (Ovid), Embase (Ovid) and EconLit identified eight cost-effectiveness models evaluating CRT-D against optimal pharmacological therapy (OPT) and/or CRT-P.
Results
The selected economic studies differed in terms of model structure, treatment path, time horizons, and sources of efficacy data. CRT-D was found cost-effective when compared to OPT but its cost-effectiveness became questionable when compared to CRT-P.
Conclusions
Cost-effectiveness of CRT-D may increase depending on improvement of all-cause mortality rates and HF mortality rates in patients who receive CRT-D, costs of the device, and battery life. In particular, future studies need to investigate longer-term mortality rates and identify CRT-P patients that will gain the most, in terms of life expectancy, from being treated with a CRT-D.This work was supported by the Center for Translational Molecular Medicine and The Netherlands Heart Foundation under the ‘Biomarkers to predict cardiac failure, arrhythmias and success of treatment’ (COHFAR) projec
Brane effective actions, kappa-symmetry and applications
This is a review on brane effective actions, their symmetries and some of their applications. Its first part covers the Green–Schwarz formulation of single M- and D-brane effective actions focusing on kinematical aspects: the identification of their degrees of freedom, the importance of world volume diffeomorphisms and kappa symmetry to achieve manifest spacetime covariance and supersymmetry, and the explicit construction of such actions in arbitrary on-shell supergravity backgrounds. Its second part deals with applications. First, the use of kappa symmetry to determine supersymmetric world volume solitons. This includes their explicit construction in flat and curved backgrounds, their interpretation as Bogomol’nyi–Prasad–Sommerfield (BPS) states carrying (topological) charges in the supersymmetry algebra and the connection between supersymmetry and Hamiltonian BPS bounds. When available, I emphasise the use of these solitons as constituents in microscopic models of black holes. Second, the use of probe approximations to infer about the non-trivial dynamics of strongly-coupled gauge theories using the anti de Sitter/conformal field theory (AdS/CFT) correspondence. This includes expectation values of Wilson loop operators, spectrum information and the general use of D-brane probes to approximate the dynamics of systems with small number of degrees of freedom interacting with larger systems allowing a dual gravitational description. Its final part briefly discusses effective actions for N D-branes and M2-branes. This includes both Super-Yang-Mills theories, their higher-order corrections and partial results in covariantising these couplings to curved backgrounds, and the more recent supersymmetric Chern–Simons matter theories describing M2-branes using field theory, brane constructions and 3-algebra considerations
The role of concomitant methotrexate dosage and maintenance over time in the therapy of rheumatoid arthritis patients treated with adalimumab or etanercept: retrospective analysis of a local registry
Ennio Giulio Favalli,1 Andrea Becciolini,1 Martina Biggioggero,2 Ilaria Bertoldi,3 Chiara Crotti,2 Maria Gabriella Raimondo,2 Antonio Marchesoni1 1Department of Rheumatology, Gaetano Pini Institute, Milan, Italy; 2Department of Clinical Sciences and Health Community, University of Milan, Division of Rheumatology, Gaetano Pini Institute, Milan, Italy; 3Pfizer Innovative Health, I&I Medical Affairs, Rome, Italy Objective: To evaluate the pattern of prescription and maintenance over time of concomitant methotrexate (MTX), and its impact on a 2-year clinical response in a cohort of rheumatoid arthritis (RA) patients treated with a first-line tumor necrosis factor alpha inhibitor (TNFi). Patients and methods: The study population included all RA patients receiving adalimumab or etanercept a as first-line biologic drug, extracted from a local registry. Enrolled patients were stratified into 3 subgroups according to baseline concomitant MTX: no MTX, low-dose MTX (≤10 mg/wk), and high-dose MTX (≥12.5 mg/wk). The 2-year persistence of the initial MTX regimen was computed by the Kaplan–Meier method, and a Cox proportional hazard model was developed to examine potential predictors of MTX withdrawal/change of dosage. European League Against Rheumatism remission and good-to-moderate response were evaluated according to baseline MTX regimen and MTX maintenance over time. Results: A total of 330 patients (163 treated with adalimumab and 167 with etanercept) were included; 141 were prescribed TNFi without MTX and 112 received low-dose and 77 high-dose concomitant MTX. Male sex, younger age, and shorter mean disease duration were predictors of high-dose MTX use. Among MTX users (76.2% parenteral and 23.8% oral), initial MTX dose persisted over time in 79.9% at 1 year and 70.2% at 2 years. Fifty-one patients (27%) underwent MTX dose de-escalation/discontinuation because of intolerance/adverse events. The 2-year EULAR remission rate was higher in the patients receiving and maintaining high-dose MTX than in those receiving low-dose or no MTX (46.2% vs 29.5% and 23.4%, respectively; p=0.009). The same was true for good-to-moderate response rate (71.2% vs 52.6% and 50.4%, respectively; p=0.031). Conclusion: In a real-life setting, about one-third of RA patients treated with TNFis experienced dose reduction/discontinuation of concomitant MTX because of intolerance/adverse events over a 2-year follow-up period. Initial high-dose MTX and its maintenance over time are associated with better 2-year clinical response. Keywords: rheumatoid arthritis, methotrexate, biologic drugs, combination therapy, etanercept, adalimuma