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1.
Health Serv Res Manag Epidemiol ; 7: 2333392820950909, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32923519

RESUMEN

OBJECTIVE: We surveyed patients who visited multiple outpatient specialty practices to understand what summary content was most helpful with the goal of optimizing meaningful outpatient clinical visit summary content. MATERIALS AND METHODS: We constructed a survey instrument to measure delivery, use, and contents of clinical visit summaries. We surveyed patients who visited with at least 2 different outpatient medical specialties to understand preferences. RESULTS: Most patients in our sample valued the summary information they received, and retained it as healthcare documentation (84%) and/or quick reference in supporting self-care (70%). Patients most commonly reported that information on results of completed tests (91%) and treatment plan instructions (89%) were very helpful. Additionally, patients expressed the importance of online access to clinical visit summary information. DISCUSSION: Most patients used the clinical visit summary as healthcare documentation, and valued online availability of their summary information. Patients most often reported that information on results of recently completed tests and specific instructions on treatment plan were very helpful. Patients who sought further information after their visit most often looked to a provider and/or online. CONCLUSIONS: Patients valued clinical visit summary accessibility and as a reference tool to summarize care and provide next steps. Optimal clinical visit summaries might collate and integrate assessments and recommendations from multiple specialties into coherent care plans for patients.

2.
Artículo en Inglés | MEDLINE | ID: mdl-24229114

RESUMEN

We study the ground-state spatial heterogeneities of the Edwards-Anderson spin-glass model with both bimodal and Gaussian bond distributions. We characterize these heterogeneities by using a general definition of bond rigidity, which allows us to classify the bonds of the system into two sets, the backbone and its complement, with very different properties. This generalizes to continuous distributions of bonds the well-known definition of a backbone for discrete bond distributions. By extensive numerical simulations we find that the topological structure of the backbone for a given lattice dimensionality is very similar for both discrete and continuous bond distributions. We then analyze how these heterogeneities influence the equilibrium properties at finite temperature and we discuss the possibility that a suitable backbone picture can be relevant to describe spin-glass phenomena.

3.
Phys Rev E Stat Nonlin Soft Matter Phys ; 86(3 Pt 1): 031121, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23030880

RESUMEN

We investigate slow nonequilibrium dynamical processes in a two-dimensional q-state Potts model with both ferromagnetic and ±J couplings. Dynamical properties are characterized by means of the mean-flipping time distribution. This quantity is known for clearly unveiling dynamical heterogeneities. Using a two-times protocol we characterize the different time scales observed and relate them to growth processes occurring in the system. In particular we target the possible relation between the different time scales and the spatial heterogeneities originated in the ground-state topology, which are associated to the presence of a backbone structure. We perform numerical simulations using an approach based on graphis processing units (GPUs) which permits us to reach large system sizes. We present evidence supporting both the idea of a growing process in the preasymptotic regime of the glassy phases and the existence of a backbone structure behind this process.

4.
J Chem Phys ; 136(6): 064113, 2012 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-22360175

RESUMEN

In a previous paper [F. Romá, A. J. Ramirez-Pastor, and J. L. Riccardo, Phys. Rev. B 72, 035444 (2005)], the critical behavior of repulsive rigid rods of length k (k-mers) on a square lattice at half coverage has been studied by using Monte Carlo (MC) simulations. The obtained results indicated that (1) the phase transition occurring in the system is a second-order phase transition for all adsorbate sizes k; and (2) the universality class of the transition changes from 2D Ising-type for monomers (k = 1) to an unknown universality class for k ≥ 2. In the present work, we revisit our previous results together with further numerical evidences, resulting from new extensive MC simulations based on an efficient exchange algorithm and using high-performance computational capabilities. In contrast to our previous conclusions (1) and (2), the new numerical calculations clearly support the occurrence of a first-order phase transition for k ≥ 2. In addition, a similar scenario was found for k-mers adsorbed on the triangular lattice at coverage k/(2k+1).


Asunto(s)
Transición de Fase , Algoritmos , Simulación por Computador , Modelos Químicos , Método de Montecarlo , Termodinámica
5.
J Chem Phys ; 132(5): 054111, 2010 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-20136309

RESUMEN

Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas which mimics a nanoporous environment. In this model, the adsorbent is modeled as one-dimensional channels of equivalent adsorption sites arranged in a triangular cross-sectional structure. Two kinds of lateral interaction energies have been considered: (1) w(L) interaction energy between nearest-neighbor particles adsorbed along a single channel and (2) w(T) interaction energy between particles adsorbed across nearest-neighbor channels. We focus on the case of repulsive transverse (w(T)>0) and attractive longitudinal (w(L)<0) lateral interactions, where a rich variety of structural orderings are observed in the adlayer depending on the value of the parameters k(B)T/w(T) (being k(B) the Boltzmann constant) and w(L)/w(T). The results reveal the existence of a first-order phase transition in the adlayer between a low-temperature "condensed" phase and a high-temperature "disordered" phase.

6.
J Chem Phys ; 130(19): 194711, 2009 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-19466859

RESUMEN

In this work we study a simple model of multilayer adsorption of noninteracting polyatomic species on homogeneous and heterogeneous surfaces. A new approximate analytic isotherm is obtained and validated by comparing with Monte Carlo simulation in one- and two-dimensional lattices. Then, we use the well-known Brunauer-Emmet-Teller (BET) approach to analyze these isotherms and to estimate the monolayer volume, v(m). In this way, we confirm previous observations that the value of the v(m) obtained by the BET equation depends strongly on adsorbate size and surface heterogeneity. In all cases, we find that the use of the BET equation leads to an underestimate of the true monolayer capacity. Nevertheless, a compensation effect is found for the adsorption on a patchwise bivariate surface, but this is not enough to eliminate the decrease of v(m) caused by the molecular size. In addition, we consider also the possibility to use the model to study the adsorption on nanotube bundles.

7.
Langmuir ; 25(16): 9227-31, 2009 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-19441827

RESUMEN

The specific area of a substrate was determined from the results of adsorption isotherms performed with a sequence of four alkanes, from methane to butane, using three different approaches. The data were first analyzed using the BET equation and the point B methods; these results were compared with those obtained using a new equation designed for examining the case of multisite occupancy. The new model specifically accounts for sites that are left uncovered in the case of adsorption by linear adsorbates. Of these three, only the last method gives essentially the same value for the specific surface area of the substrate when different adsorbates are used to measure it. The other two, more traditional, approaches give values of the specific surface area that decrease as the length of the adsorbate used increases.

8.
J Phys Chem B ; 112(29): 8619-23, 2008 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-18590306

RESUMEN

A molecular model is proposed to study the enantioselective adsorption of chiral species on metallic surfaces modified through the preadsorption of another chiral species, known as template surfaces. It is found that anisotropic and exclusive interactions among adsorbed species are essential factors in the enantioselective process. It is shown how the formation of compact structures explains the fact that an enantiomer of species B having the same symmetry as the template species A can be preferentially adsorbed with respect to the other enantiomer of species B, thus producing enantioselectivity. The model predicts enantioselectivity peaks on a limited range of the template coverage, as typically observed experimentally in some systems.

9.
Phys Rev Lett ; 98(9): 097203, 2007 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-17359192

RESUMEN

We analyze numerically the violation of the fluctuation-dissipation theorem (FDT) in the +/-J Edwards-Anderson (EA) spin-glass model. Using single spin probability densities we reveal the presence of strong dynamical heterogeneities, which correlate with ground-state information. The physical interpretation of the results shows that the spins can be divided into two sets. In 3D, one set forms a compact structure which presents a coarseninglike behavior with its characteristic violation of the FDT, while the other asymptotically follows the FDT. Finally, we compare the dynamical behavior observed in 3D with 2D.

10.
J Chem Phys ; 125(21): 214705, 2006 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-17166038

RESUMEN

Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas of interacting monomers adsorbed on one-dimensional channels arranged in a triangular cross-sectional structure. Two kinds of lateral interaction energies have been considered: (1) w(L), interaction energy between nearest-neighbor particles adsorbed along a single channel and (2) w(T), interaction energy between particles adsorbed across nearest-neighbor channels. We focus on the case of repulsive transverse interactions (w(T)>0), where a rich variety of structural orderings are observed in the adlayer, depending on the value of the parameters k(B)Tw(T) (being k(B) the Boltzmann constant) and w(L)w(T). For w(L)w(T)=0, successive planes are uncorrelated, the system is equivalent to the triangular lattice, and the well-known ([square root] 3 x [square root] 3) [([square root] 3 x ([square root] 3)(*)] ordered phase is found at low temperatures and a coverage, theta, of 13. In the more general case (w(L)/w(T) not equal 0), a competition between interactions along a single channel and a transverse coupling between sites in neighboring channels leads to a three-dimensional adsorbed layer. Consequently, the ([square root] 3 x ([square root] 3) and (([square root] 3 x ([square root] 3)(*) structures "propagate" along the channels and new ordered phases appear in the adlayer. Each ordered phase is separated from the disordered state by a continuous order-disorder phase transition occurring at a critical temperature, T(c), which presents an interesting dependence with w(L)/w(T). The Monte Carlo technique was combined with the recently reported free energy minimization criterion approach (FEMCA) [F. Roma et al., Phys. Rev. B 68, 205407 (2003)] to predict the critical temperatures of the order-disorder transformation. The excellent qualitative agreement between simulated data and FEMCA results allows us to interpret the physical meaning of the mechanisms underlying the observed transitions.


Asunto(s)
Simulación por Computador , Método de Montecarlo , Transición de Fase , Absorción , Frío , Cinética , Modelos Químicos
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