481 research outputs found
The analyticity region of the hard sphere gas. Improved bounds
We find an improved estimate of the radius of analyticity of the pressure of
the hard-sphere gas in dimensions. The estimates are determined by the
volume of multidimensional regions that can be numerically computed. For ,
for instance, our estimate is about 40% larger than the classical one.Comment: 4 pages, to appear in Journal of Statistical Physic
Effects of boundary conditions on irreversible dynamics
We present a simple one-dimensional Ising-type spin system on which we define
a completely asymmetric Markovian single spin-flip dynamics. We study the
system at a very low, yet non-zero, temperature and we show that for empty
boundary conditions the Gibbs measure is stationary for such dynamics, while
introducing in a single site a condition the stationary measure changes
drastically, with macroscopical effects. We achieve this result defining an
absolutely convergent series expansion of the stationary measure around the
zero temperature system. Interesting combinatorial identities are involved in
the proofs
Cluster expansion for abstract polymer models. New bounds from an old approach
We revisit the classical approach to cluster expansions, based on tree
graphs, and establish a new convergence condition that improves those by
Kotecky-Preiss and Dobrushin, as we show in some examples. The two ingredients
of our approach are: (i) a careful consideration of the Penrose identity for
truncated functions, and (ii) the use of iterated transformations to bound
tree-graph expansions.Comment: 16 pages. This new version, written en reponse to the suggestions of
the referees, includes more detailed introductory sections, a proof of the
generalized Penrose identity and some additional results that follow from our
treatmen
Abstract polymer models with general pair interactions
A convergence criterion of cluster expansion is presented in the case of an
abstract polymer system with general pair interactions (i.e. not necessarily
hard core or repulsive). As a concrete example, the low temperature disordered
phase of the BEG model with infinite range interactions, decaying polynomially
as with , is studied.Comment: 19 pages. Corrected statement for the stability condition (2.3) and
modified section 3.1 of the proof of theorem 1 consistently with (2.3). Added
a reference and modified a sentence at the end of sec. 2.
New approaches in the management of multiple sclerosis
Multiple sclerosis (MS) is a central nervous system chronic inflammatory disease that is characterized by an extensive and complex immune response. Scientific advances have occurred in immunology, pathophysiology, and diagnostic and clinical assessment tools, and recent discovery of unique therapeutic targets has spurred numerous Phase II and Phase III clinical trials. Reductions in MS relapse rates and improvements in T2 or gadolinium-enhancing lesion burdens have been reported from Phase III trials that include fingolimod, alemtuzumab, cladribine, and rituximab. Promising Phase II trial data exist for teriflunomide, daclizumab, laquinimod, and fumarate. The optimism created by these favorable findings must be tempered with evaluation of the adverse effect profile produced by these new agents. Given the discovery of progressive multifocal leukoencephalopathy with the use of natalizumab, ongoing vigilance for rare and life-threatening reactions due to new agents should be paramount. Patients with MS often experience difficulty with ambulation, spasticity, and cognition. Recent clinical trial data from two Phase III dalfampridine-SR trials indicate certain patients receive benefits in ambulation. This article provides an overview of data from clinical trials of newer agents of potential benefit in MS
Is post orthognathic maxillary sinusitis related to sino-nasal anatomical alterations?
Le Fort I osteotomies have been used for more than five decades, but their impact on nasal and paranasal cavities physiology, has not been studied deeply. In this paper we want to analyse the possible correlation between post-orthognathic findings and prevalence of sinusitis which require surgical treatment. A retrospective cohort study was designed in 2017; the study was designed and carried out in the Verona University maxillo-facial department, a referral centre for orthognathic surgery. The study population is made of 64 patients that underwent orthognathic surgery (To treat class II or III malocclusion) between 2010 and 2015. Inclusion criteria were the availability of a Cone Beam Computed Tomography (CBCT) before surgery and one between 12 and 24 months after orthognathic surgery. Exclusion criteria were smoking habit and previous orthognathic procedures. During follow-up time prevalence of sinusitis was 18.5% and some patients required a secondary surgery to treat sinusitis. Surgery induced anatomic alterations were frequent in patients with sinusitis, sings and symptoms of sinusitis show positive correlation with anatomic alterations
Analyticity of the SRB measure of a lattice of coupled Anosov diffeomorphisms of the torus
We consider the "thermodynamic limit"of a d-dimensional lattice of hyperbolic
dynamical systems on the 2-torus, interacting via weak and nearest neighbor
coupling. We prove that the SRB measure is analytic in the strength of the
coupling. The proof is based on symbolic dynamics techniques that allow us to
map the SRB measure into a Gibbs measure for a spin system on a
(d+1)-dimensional lattice. This Gibbs measure can be studied by an extension
(decimation) of the usual "cluster expansion" techniques.Comment: 28 pages, 2 figure
Balancing Affinity, Selectivity, and Cytotoxicity of Hydrazone-Based G-Quadruplex Ligands for Activation of Interferon β Genes in Cancer Cells
G-quadruplex (G4) ligands are investigated to discover new anticancer drugs with increased cell-killing potency. These ligands can induce genome instability and activate innate immune genes at non-cytotoxic doses, opening the discovery of cytostatic immune-stimulating ligands. However, the interplay of G4 affinity/selectivity with cytotoxicity and immune gene activation is not well-understood. We investigated a series of closely related hydrazone derivatives to define the molecular bases of immune-stimulation activity. Although they are closely related to each other, such derivatives differ in G4 affinity, cytotoxicity, genome instability, and immune gene activation. Our findings show that G4 affinity of ligands is a critical feature for immune gene activation, whereas a high cytotoxic potency interferes with it. The balance of G4 stabilization versus cytotoxicity can determine the level of immune gene activation in cancer cells. Thus, we propose a new rationale based on low cell-killing potency and high immune stimulation to discover effective anticancer G4 ligands
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