13,587 research outputs found
Conformations Of A Model Protein Revealed By An Aggregating Cuᴵᴵ Porphyrin: Sensing The Difference
Aggregated t-CuP binds to poly-L-glutamate through supramolecular interactions, revealing itself to be an extremely sensitive probe for the major conformations of the polymeric scaffold
Target motion estimation via a multistatic FSR
The focus of this paper is on the estimation of the kinematic parameters of moving targets
via a MIMO Forward Scatter Radar (FSR) system. A sub-optimum estimation technique is considered
that exploits the information concerning the time instants at which the target crosses the individual
baselines to retrieve the motion parameters. The accuracy of such technique is firstly investigated
from a theoretical point of view and then the effectiveness of the proposed approach is demonstrated
by applying it to live MIMO FSR data. Shown results prove the practical applicability of the proposed
technique
Structural Properties of the Disordered Spherical and other Mean Field Spin Models
We extend the approach of Aizenman, Sims and Starr for the SK-type models to
their spherical versions. Such an extension has already been performed for
diluted spin glasses. The factorization property of the optimal structures
found by Guerra for the SK model, which holds for diluted models as well, is
verified also in the case of spherical systems, with the due modifications.
Hence we show that there are some common structural features in various mean
field spin models. These similarities seem to be quite paradigmatic, and we
summarize the various techniques typically used to prove the structural
analogies and to tackle the computation of the free energy per spin in the
thermodynamic limit.Comment: 24 page
POD and SPOD analysis of vertical liquid sheet
Modal analysis of thin liquid sheet driven by a harmonic forcing in the lateral velocity component at the inlet section is performed. Proper orthogonal decomposition (POD) and spectral POD (SPOD) techniques have been applied on two-dimensional two-phase numerical simulations data, obtained with the VOF approach, to characterize the main spatial and temporal structures. The investigation is carried out varying the Weber number and the Reynolds number. In supercritical regime (Weber number, > 1) both POD and SPOD techniques yield only leading sinuous modes, featuring a traveling perturbation. Spectral analysis confirms the occurrence of a discontinuity in frequency response between the supercritical and subcritical regimes. In subcritical regime ( < 1) the excitation of a combined sinuous-varicose motion is detected when the system is driven at resonance frequency for relatively high Reynolds numbers
Ground states of a two phase model with cross and self attractive interactions
We consider a variational model for two interacting species (or phases), subject to cross and self attractive forces. We show existence and several qualitative properties of minimizers. Depending on the strengths of the forces, different behaviors are possible: phase mixing or phase separation with nested or disjoint phases. In the case of Coulomb interaction forces, we characterize the ground state configurations
Stability results for nonlocal geometric evolutions and limit cases for fractional mean curvature flows
We introduce a notion of uniform convergence for local and nonlocal curvatures. Then, we propose an abstract method to prove the convergence of the corresponding geometric flows, within the level set formulation. We apply such a general theory to characterize the limits of s-fractional mean curvature flows as (Formula presented.) and (Formula presented.) In analogy with the s-fractional mean curvature flows, we introduce the notion of s-Riesz curvature flows and characterize its limit as (Formula presented.) Eventually, we discuss the limit behavior as (Formula presented.) of the flow generated by a regularization of the r-Minkowski content
Prevalence and pharmacologic management of familial hypercholesterolemia in an unselected contemporary cohort of patients with stable coronary artery disease
INTRODUCTION:
Familial hypercholesterolemia (FH) is an inherited disorder characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) associated with premature cardiovascular disease.
METHODS:
Using the data from the START (STable Coronary Artery Diseases RegisTry) study, a nationwide, prospective survey on patients with stable coronary artery disease (CAD), we described prevalence and lipid lowering strategies commonly employed in these patients. The study population was divided into "definite/probable FH," defined as a Dutch Lipid Clinic Network (DLCN) score ≥6, "possible FH" with DLCN 3-5, and "unlikely FH" in presence of a DLCN <3.
RESULTS:
Among the 4030 patients with the DLCN score available, 132 (3.3%) were classified as FH (2.3% with definite/probable and 1.0% with possible FH) and 3898 (96.7%) had unlikely FH. Patients with both definite/probable and possible FH were younger compared to patients not presenting FH. Mean on-treatment LDL-C levels were 107.8 ± 41.5, 84.4 ± 40.9, and 85.8 ± 32.3 (P < 0.0001) and a target of ≤70 mg/dL was reached in 10.9%, 30.0%, and 22.0% (P < 0.0001) of patents with definite/probable, possible FH, and unlikely FH, respectively. Statin therapy was prescribed in 85 (92.4%) patients with definite/probable FH, in 38 (95.0%) with possible FH, and in 3621 (92.9%) with unlikely FH (P = 0.86). The association of statin and ezetimibe, in absence of other lipid-lowering therapy, was more frequently used in patients with definite/probable FH compared to patients without FH (31.5% vs 17.5% vs 9.5%; P < 0.0001).
CONCLUSIONS:
In this large cohort of consecutive patients with stable CAD, FH was highly prevalent and generally undertreated with lipid lowering therapies
Mechanism For Copper(II)-Mediated Disaggregation Of A Porphyrin J-Aggregate
J-aggregates of anionic meso-tetrakis(4-sulfonatophenyl)porphyrin form at intermediate pH (2.3–3.1) in the presence of NiSO₄ or ZnSO₄ (ionic strength, I.S. = 3.2 M). These aggregates convert to monomeric porphyrin units via metallation with copper(II) ions. The kinetics for the disassembly process, as monitored by UV/vis spectroscopy, exhibits zeroth-order behavior. The observed zeroth-order rate constants show a two-term dependence on copper(II) ion concentrations: linear and second order. Also observed is an inverse dependence on hydrogen ion concentration. Activation parameters have been determined for the disassembly process leading to ΔH^≠ = (+163 ± 15) kJ·mol⁻¹ and ΔS^≠ = (+136 ± 11) J·K⁻¹. A mechanism is proposed in which copper(II) cation is in pre-equilibrium with a reactive site at the rim of the J-aggregate. An intermediate copper species is thus formed that eventually leads to the final metallated porphyrin either through an assisted attack of a second metal ion or through a direct insertion of the metal cation into the macrocycle core
Invariance: a Theoretical Approach for Coding Sets of Words Modulo Literal (Anti)Morphisms
Let be a finite or countable alphabet and let be literal
(anti)morphism onto (by definition, such a correspondence is determinated
by a permutation of the alphabet). This paper deals with sets which are
invariant under (-invariant for short).We establish an
extension of the famous defect theorem. Moreover, we prove that for the
so-called thin -invariant codes, maximality and completeness are two
equivalent notions. We prove that a similar property holds in the framework of
some special families of -invariant codes such as prefix (bifix) codes,
codes with a finite deciphering delay, uniformly synchronized codes and
circular codes. For a special class of involutive antimorphisms, we prove that
any regular -invariant code may be embedded into a complete one.Comment: To appear in Acts of WORDS 201
Supergiant Fast X-ray Transients uncovered by the EXTraS project: flares reveal the development of magnetospheric instability in accreting neutron stars
The low luminosity, X-ray flaring activity, of the sub-class of high mass
X-ray binaries called Supergiant Fast X-ray Transients, has been investigated
using XMM-Newton public observations, taking advantage of the products made
publicly available by the EXTraS project. One of the goals of EXTraS was to
extract from the XMM-Newton public archive information on the aperiodic
variability of all sources observed in the soft X-ray range with EPIC (0.2-12
keV). Adopting a Bayesian block decomposition of the X-ray light curves of a
sample of SFXTs, we picked out 144 X-ray flares, covering a large range of soft
X-ray luminosities (1e32-1e36 erg/s). We measured temporal quantities, like the
rise time to and the decay time from the peak of the flares, their duration and
the time interval between adjacent flares. We also estimated the peak
luminosity, average accretion rate and energy release in the flares. The
observed soft X-ray properties of low-luminosity flaring activity from SFXTs is
in qualitative agreement with what is expected by the application of the
Rayleigh-Taylor instability model in accreting plasma near the neutron star
magnetosphere. In the case of rapidly rotating neutron stars, sporadic
accretion from temporary discs cannot be excluded.Comment: Accepted for publication in MNRAS (accepted 2019 May 1; received 2019
April 30; in original form 2019 February 25). 22 pages, 16 figures, 3 tables
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