Backbone structure of the Edwards-Anderson spin-glass model

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 topologicalstructure 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.Fil: Romá, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - San Luis. Instituto de Física Aplicada; Argetnina;Fil: Risau-Gusman, S.. Comisión Nacional de Energía Atomica. Gerencia del Área de Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (cab). División Física Estadistica; Argentina

Micromagnetic simulation study of a disordered model for one-dimensional granular perovskite manganite oxide nanostructures

Chemical techniques are an efficient method to synthesize one-dimensional perovskite manganite oxide nanostructures with a granular morphology, that is, formed by arrays of monodomain magnetic nanoparticles. Integrating the stochastic Landau-Lifshitz-Gilbert equation, we simulate the dynamics of a simple disordered model for such materials that only takes into account the morphological characteristics of their nanograins. We show that it is possible to describe reasonably well experimental hysteresis loops reported in the literature for single La0.67Ca0.33MnO3 nanotubes and powders of these nanostructures, simulating small systems consisting of only 100 nanoparticles.Fil: Longone, Pablo Jesus. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Romá, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

First-order phase transitions in repulsive rigid k-mers on two-dimensional lattices

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).Fil: Pasinetti, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Romá, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Magnetic hysteresis behavior of granular manganite La0.67Ca0.33MnO3 nanotubes

A silicon micromechanical torsional oscillator is used to measure the hysteresis loops of two manganite La0.67Ca0.33MnO3 nanotubes at different temperatures, applying an external field along its main axes. These structures are composed of nanograins with a ferromagnetic core surrounded by a dead layer. Micromagnetic calculations based on the stochastic Landau-Lifshitz-Gilbert equation are performed to validate a simple model that allows for quantitatively describing the ferromagnetic behavior of the system. Further simulations are used to analyze the experimental data more in depth and to calculate the coercive field, the saturation and remanent magnetizations, and the effective magnetic volume for single nanotubes, over a wide temperature range.Fil: Dolz, Moira Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Física; ArgentinaFil: Calderon Rivero, Sergio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Pastoriza, Hernan. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Romá, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Quasi-chemical approximation for polyatomics: Statistical thermodynamics of adsorption

The statistical thermodynamics of interacting polyatomic adsorbates (k-mers) on homogeneous surfaces was developed on a generalization in the spirit of the lattice-gas model and the quasi-chemical approximation (QCA). The new theoretical framework is obtained by combining (i) the exact analytical expression for the partition function of non-interacting linear k-mers adsorbed in one dimension and its extension to higher dimensions, and (ii) a generalization of the classical QCA in which the adsorbate can occupy more than one adsorption site. The coverage and temperature dependence of the Helmholtz free energy, chemical potential, configurational entropy, configurational energy, isosteric heat of adsorption and specific heat are given. The formalism reproduces the classical QCA for monomers, leads to the exact statistical thermodynamics of interacting k-mers adsorbed in one dimension, and provides a close approximation for two-dimensional systems accounting multisite occupancy. Comparisons with analytical data from Bragg-Williams approximation (BWA) and Monte Carlo simulations are performed in order to test the validity of the theoretical model. The resulting thermodynamic description is significantly better than the BWA and still mathematically handable.Fil: Dávila, M.. Universidad Nacional de San Luis; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro | Universidad Nacional de Cuyo. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro; ArgentinaFil: Romá, Federico José. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Riccardo, Jose Luis. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Ramirez Pastor, Antonio Jose. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentin

Novel order parameter to describe the critical behavior of Ising spin glass models

A novel order parameter Φ for spin glasses is defined based on topological criteria and with a clear physical interpretation. Φ is first investigated for well known magnetic systems and then applied to the Edwards-Anderson ±J model on a square lattice, comparing its properties with the usual q order parameter. Finite size scaling procedures are performed. Results and analyses based on Φ confirm a zero temperature phase transition and allow to identify the low temperature phase. The advantages of Φ are brought out and its physical meaning is established.Fil: Romá, Federico José. Universidad Nacional de San Luis; ArgentinaFil: Nieto Quintas, Felix Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Vogel, E. E.. Universidad de La Frontera; Chil

A simple model for studying multilayer adsorption of noninteracting polyatomic species on homogeneous and heterogeneous surfaces

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, vm. In this way, we confirm previous observations that the value of the vm 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 vm caused by the molecular size. In addition, we consider also the possibility to use the model to study the adsorption on nanotube bundles.Fil: Sanchez Varretti, Fabricio Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Grupo Vinculado Bionanotecnología y Sistemas Complejos | Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Grupo Vinculado Bionanotecnología y Sistemas Complejos. - Universidad Tecnológica Nacional. Facultad Regional San Rafael. Grupo Vinculado Bionanotecnología y Sistemas Complejos; ArgentinaFil: García, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentina. Universidad Tecnologica Nacional. Facultad Regional San Rafael; ArgentinaFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Romá, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentin

Comparative Analysis of Chromatin-Delivered Biomarkers in the Monitoring of Sepsis and Septic Shock: A Pilot Study

[EN] Sepsis management remains one of the most important challenges in modern clinical practice. Rapid progression from sepsis to septic shock is practically unpredictable, hence the critical need for sepsis biomarkers that can help clinicians in the management of patients to reduce the proba-bility of a fatal outcome. Circulating nucleoproteins released during the inflammatory response to infection, including neutrophil extracellular traps, nucleosomes, and histones, and nuclear pro-teins like HMGB1, have been proposed as markers of disease progression since they are related to inflammation, oxidative stress, endothelial damage, and impairment of the coagulation response, among other pathological features. The aim of this work was to evaluate the actual potential for decision making/outcome prediction of the most commonly proposed chromatin-related bi-omarkers (i.e., nucleosomes, citrullinated H3, and HMGB1). To do this, we compared different ELISA measuring methods for quantifying plasma nucleoproteins in a cohort of critically ill pa-tients diagnosed with sepsis or septic shock compared to nonseptic patients admitted to the inten-sive care unit (ICU), as well as to healthy subjects. Our results show that all studied biomarkers can be used to monitor sepsis progression, although they vary in their effectiveness to separate sepsis and septic shock patients. Our data suggest that HMGB1/citrullinated H3 determination in plasma is potentially the most promising clinical tool for the monitoring and stratification of septic patients.This activity received funding from the European Institute of Innovation and Technology (EIT). This body of the European Union receives support from the European Union's Horizon 2020 research and innovation program. C.R-M. thanks GVA for starting grant (GV/2018/127) and Spanish Ministry of Science and Innovation for research project (PID2020-119127RA-I00); J.B-G thanks ISCIII, AES2018 for iPFIS fellowship (IFI18/00015) and GVA for APOTI fellowship (APOTIP/2017/012); CG thanks Spanish Ministry of Universities for fellowship FPU18/03969; J.L.G-G and F.V.P thank INCLIVA, GVA and AES2016 and AES2019 (ISCIII) for starting grant (GV/2014/132), project PI16/01036 and PI19/00994 and project DTS17/00132 (co-financed by the ERDF). The project leading to these results has received funding from "la Caixa" Foundation (ID 100010434), under agreement CI18-0009. C.R-M., F.V.P. and A.M. thank Grand Challenges Canada. : We want to particularly acknowledge the patients and the INCLIVA Biobank (PT17/0015/0049; B.000768 ISCIII) integrated in the Valencian Biobanking Network and the Spanish National Biobanks Network for their collaboration.Beltrán-García, J.; Manclus Ciscar, JJ.; García-López, EM.; Carbonell, N.; Ferreres, J.; Rodríguez-Gimillo, M.; Garcés, C.... (2021). Comparative Analysis of Chromatin-Delivered Biomarkers in the Monitoring of Sepsis and Septic Shock: A Pilot Study. International Journal of Molecular Sciences. 22(18):1-15. https://doi.org/10.3390/ijms22189935115221

The science of storytelling: different levels of narrative integration in teaching innovation applied to Human Physiology

[EN] The incorporation of narrative features into teaching materials of different formats, such as graphic and audiovisual ones, has proven to be an efficient way of encouraging student motivation. Besides, it strengthens the teaching of abstract concepts like those frequent in experimental sciences, such as Physiology, a basic subject in life sciences studies. From the Department of Physiology of the University of Valencia we present the creation of a teaching innovation group focused on the development of Narrative Physiology, FISIONARR, with the aim of promoting the narrative nature of teaching Physiology through two strategic lines. The first one focuses on graphic narrative and its integration as a teaching tool at different levels; the second deals with the generation of audiovisual narrative. In this sense, specific audiovisual material has been prepared for a series of videos entitled " Invisible Physiology", and as a conductive element of the digital educational escape room "Alimental, querida Watson".[ES] La incorporación de elementos narrativos en material docente de distintos formatos gráficos y audiovisuales es una manera eficiente de incentivar la motivación del estudiantado y de reforzar la docencia de conceptos abstractos como los relacionados con ciencias experimentales como la Fisiología, materia básica en estudios de ciencias de la salud. Desde el Departamento de Fisiología de la Universitat de València presentamos la creación de un grupo de innovación docente centrado en el uso de la Fisiología Narrativa, FISIONARR, con el objetivo de potenciar el carácter narrativo de la docencia en Fisiología a través de dos líneas estratégicas. La primera de ellas se centra en la narrativa gráfica y en su integración como herramienta docente a distintos niveles. La segunda trata sobre la generación de narrativa audiovisual y concretamente de ha elaborado material para una serie de videos titulados “La Fisiología Invisible” y como elemento conductor de la escape room educacional digital “Alimental, querida Watson”.Olaso Gonzalez, G.; Calvo Saiz, C.; González Cabo, P.; García Giménez, JL.; Gómez-Cabrera, MC.; Arribas Rodríguez, S.; Gal Iglesias, B.... (2023). La ciencia de contar historias: distintos niveles de integración narrativa en innovación docente aplicada a la Fisiología Humana. Editorial Universitat Politècnica de València. 1050-1060. https://doi.org/10.4995/INRED2023.2023.166551050106

Extracellular histones activate autophagy and apoptosis via mTOR signaling in human endothelial cells

Circulating histones have been proposed as targets for therapy in sepsis and hyperinflammatory symptoms. However, the proposed strategies have failed in clinical trials. Although different mechanisms for histone-related cytotoxicity are being explored, those mediated by circulating histones are not fully understood. Extracellular histones induce endothelial cell death, thereby contributing to the pathogenesis of complex diseases such as sepsis and septic shock. Therefore, the comprehension of cellular responses triggered by histones is capital to design effective therapeutic strategies. Here we report how extracellular histones induce autophagy and apoptosis in a dose-dependent manner in cultured human endothelial cells. In addition, we describe how histones regulate these pathways via Sestrin2/AMPK/ULK1-mTOR and AKT/mTOR. Furthermore, we evaluate the effect of Toll-like receptors in mediating autophagy and apoptosis demonstrating how TLR inhibitors do not prevent apoptosis and/or autophagy induced by histones. Our results confirm that histones and autophagic pathways can be considered as novel targets to design therapeutic strategies in endothelial damage