Creeping and structural effects in Faradaic artificial muscles

Reliable polymeric motors are required for the construction of rising accurate robots for surgeon assistance. Artificial muscles based on the electrochemistry of conducting polymers fulfil most of the required characteristics, except the presence of creeping effects during actuation. To avoid it, or to control it, a deeper knowledge of its physicochemical origin is required. With this aim here bending bilayer tape/PPy-DBSH (Polypyrrole-dodecylbenzylsulphonic acid) full polymeric artificial muscles were cycled between −2.5 and 1 V in aqueous solutions with parallel video recording of the described angular movement. Coulo-voltammetric (charge-potential, QE), dynamo-voltammetric (angle-potential, αE), and coulo-dynamic (charge-angle, Qα) muscular responses corroborate that 10 % of the charge is consumed by irreversible reactions overlapping the polymer reduction at the most cathodic potentials. In parallel, the range of the bending angular movement (145°) shifts by 15° per cycle (creeping effect) pointing to the irreversible charge as possible origin of the irreversible swelling of the PPy-DBS film. Different slopes in the closed loop part of the QE identify the different reaction driven structural processes in the film: oxidation-shrinking, oxidation compaction, reduction-relaxation, reduction-swelling, and reduction-vesicle’s formation. Despite the irreversible charge fraction, the muscle motor keeps a Faradaic behaviour: described angles are linear functions of the consumed charge in the full potential range

Ward identity and electrical conductivity in hot QED

We study the Ward identity for the effective photon-electron vertex summing the ladder diagrams contributing to the electrical conductivity in hot QED at leading logarithmic order. It is shown that the Ward identity requires the inclusion of a new diagram in the integral equation for the vertex that has not been considered before. The real part of this diagram is subleading and therefore the final expressions for the electrical conductivity at leading logarithmic order are not affected.Comment: 25 pages with 5 eps figures, discussion in section 3 improved; to appear in JHE

Structural Electrochemistry from Freestanding Polypyrrole Films: Full Hydrogen Inhibition from Aqueous Solutions

Free-standing polypyrrole films, being the metal–polymer contact located several millimeters outside the electrolyte, give stationary closed coulovoltammetric (charge/potential) loop responses to consecutive potential sweeps from –2.50 V to 0.65 V in aqueous solutions. The continuous and closed charge evolution corroborates the presence of reversible film reactions (electroactivity), together high electronic and ionic conductivities in the full potential range. The closed charge loop demonstrates that the irreversible hydrogen evolution is fully inhibited from aqueous solutions of different salts up to –2.5 V vs Ag/AgCl. The morphology of the closed charge loops shows abrupt slope changes corresponding to the four basic components of the structural electrochemistry for a 3D electroactive gel: reduction-shrinking, reduction-compaction, oxidation-relaxation, and oxidation-swelling. Freestanding films of conducting polymers behave as 3D gel electrodes (reactors) at the chain level, where reversible electrochemical reactions drive structural conformational and macroscopic (volume variation) changes. Very slow hydrogen evolution is revealed by coulovoltammetric responses at more cathodic potentials than –1.1 V from strong acid solutions, or in neutral salts self-supported blend films of polypyrrole with large organic acids. Conducting polymers overcome graphite, mercury, lead, diamond, or carbon electrodes as hydrogen inhibitors, and can compete with them for some electro-analytical and electrochemical applications in aqueous solutions

Measurement of procalcitonin in saliva of pigs: a pilot study

©2022. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published, version of a Published Work that appeared in final form in BMC Veterinary Research. To access the final edited and published work see https://doi.org/10.1186/s12917-022-03240-5Background: Procalcitonin (PCT) is a widely used biomarker of sepsis in human medicine and can have potential applications in the veterinary field. This study aimed to explore whether PCT could be measured in the saliva of pigs and whether its concentration changes in sepsis. Therefore, a specific assay was developed and analytically validated, and changes in PCT concentration were evaluated in two conditions: a) in an experimental model of sepsis produced by the administration of lipopolysaccharide (LPS) to pigs (n = 5), that was compared with a model of non‑septic inflammation induced by turpentine oil (n = 4), and b) in healthy piglets (n = 11) compared to piglets with meningitis (n = 20), a disease that usually involves sepsis and whose treatment often requires large amounts of antibiotics in farms. Results: The assay showed coefficients of variation within the recommended limits and adequate linearity after serial sample dilutions. The method’s detection limit was set at 68 μg/L, and the lower limit of quantification was 414 μg/L. In the LPS experiment, higher concentrations of PCT were found after 24 h in the animals injected with LPS (mean = 5790 μg/L) compared to those treated with turpentine oil (mean = 2127 μg/L, P = 0.045). Also, animals with meningitis had higher concentrations of PCT (mean = 21515 μg/L) than healthy pigs (mean = 6096 μg/L, P value < 0.0001). Conclusions: According to these results, this assay could be potentially used as a tool for the non‑invasive detection of sepsis in pigs, which is currently a topic of high importance due to antibiotic use restriction

Medical image modality classification using discrete Bayesian Networks

In this paper we propose a complete pipeline for medical image modality classification focused on the application of discrete Bayesian network classifiers. Modality refers to the categorization of biomedical images from the literature according to a previously defined set of image types, such as X-ray, graph or gene sequence. We describe an extensive pipeline starting with feature extraction from images, data combination, pre-processing and a range of different classification techniques and models. We study the expressive power of several image descriptors along with supervised discretization and feature selection to show the performance of discrete Bayesian networks compared to the usual deterministic classifiers used in image classification. We perform an exhaustive experimentation by using the ImageCLEFmed 2013 collection. This problem presents a high number of classes so we propose several hierarchical approaches. In a first set of experiments we evaluate a wide range of parameters for our pipeline along with several classification models. Finally, we perform a comparison by setting up the competition environment between our selected approaches and the best ones of the original competition. Results show that the Bayesian Network classifiers obtain very competitive results. Furthermore, the proposed approach is stable and it can be applied to other problems that present inherent hierarchical structures of classes

Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24-/- mouse model of HGPS. Challenge of Zmpste24-/- mice with the ß-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24-/- cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24-/- progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death.Peer ReviewedPostprint (published version

MODELO INTELIGENTE PARA BASES DE DATOS DISTRIBUIDAS

RESUMENEn este trabajo trataremos el problema del diseño del “Modelo Inteligente para Sistemas de Bases de Datos Distribuidas”. Particularmente, nos proponemos diseñar el modelo canónico a través del manejo ontológico de la información. Para esto se diseñan ontologías que permitirán describir una base de datos como un conjunto de términos representacionales de sus diferentes componentes. En estas ontologías, las definiciones asocian clases, relaciones, funciones, entre otras cosas, de entidades en el universo del discurso de las bases de datos, para describir el significado de las bases de datos, sus componentes, restricciones, etc. La razón de usar ontologías es que ellas definen conceptos y relaciones dentro de un marco taxonómico, cuya conceptualización está representada de una manera formal, legible y utilizable. En trabajos anteriores [14] se ha propuesto un modelo de referencia y una arquitectura para la integración de Bases de Datos en donde se plantea la necesidad de definir un modelo canónico. Como continuación de estos trabajos, en este artículo se describen las taxonomías ontológicas que componen el modelo de referencia para la integración de bases datos, y se diseña el Modelo Canónico usando dicha noción ontológica. De esta manera, se define el proceso de integración entre los diferentes tipos de bases de datos, estas bases de datos componentes pueden ser: Relacionales, Orientadas a Objeto, Difusas, Inteligentes y Multimedia. Así, el esquema ontológico describe los conceptos, operaciones y restricciones, tanto de las bases de datos componentes como de su proceso de integración.Además en este trabajo se muestra también los axiomas para cada una de los esquemas ontológicos utilizando lógica de predicado de primer orden.PALABRAS CLAVESEsquema ontológicoModelo Canónico de DatosBases de Datos Distribuidas InteligentesIntegración de Bases de DatosABSTRACTIn this abstract we will analyze-look at with the problem of the design of the "Intelligent Model for Distributed Database System".We particularly set out to design the canonical model through the ontological handling of the information. To do so,ontology is designed that allow the description of a database like a set of representative terms of their different components. In this ontology, the definitions associate classes, relations, functions, among other things, of organizations in the speech universe of the data bases, to describe their meaning, its components, restrictions, etc. The reason for using ontology is that it defines concepts and relations within a taxonomic frame, whose conceptualization is represented in a formal, legible and usable way. In previous works [14] a reference model and architecture for the integration of database the need to define an intelligent canonical model was proposed. Like continuation of these works, in this article the ontological taxonomies are described, determining the component of the model of reference for the integration of database, and the Canonical Model is designed using this ontological notion. By doing so, the process of integration between the different types of database is defined. These component data bases can be: Relational, OO, Fuzzy, Intelligent and Multimedia. Thus, the ontological scheme describes the concepts, operations and restrictions, as well as, the component database and its process of integration. In this work there are also the axioms for each one of the ontological schemes using first-order predicate logic.KEYWORDSOntological SchemeCanonical data ModelDistributed Database IntelligentDatabase Integratio

MODELO INTELIGENTE PARA BASES DE DATOS DISTRIBUIDAS

RESUMENEn este trabajo trataremos el problema del diseño del “Modelo Inteligente para Sistemas de Bases de Datos Distribuidas”. Particularmente, nos proponemos diseñar el modelo canónico a través del manejo ontológico de la información. Para esto se diseñan ontologías que permitirán describir una base de datos como un conjunto de términos representacionales de sus diferentes componentes. En estas ontologías, las definiciones asocian clases, relaciones, funciones, entre otras cosas, de entidades en el universo del discurso de las bases de datos, para describir el significado de las bases de datos, sus componentes, restricciones, etc. La razón de usar ontologías es que ellas definen conceptos y relaciones dentro de un marco taxonómico, cuya conceptualización está representada de una manera formal, legible y utilizable. En trabajos anteriores [14] se ha propuesto un modelo de referencia y una arquitectura para la integración de Bases de Datos en donde se plantea la necesidad de definir un modelo canónico. Como continuación de estos trabajos, en este artículo se describen las taxonomías ontológicas que componen el modelo de referencia para la integración de bases datos, y se diseña el Modelo Canónico usando dicha noción ontológica. De esta manera, se define el proceso de integración entre los diferentes tipos de bases de datos, estas bases de datos componentes pueden ser: Relacionales, Orientadas a Objeto, Difusas, Inteligentes y Multimedia. Así, el esquema ontológico describe los conceptos, operaciones y restricciones, tanto de las bases de datos componentes como de su proceso de integración.Además en este trabajo se muestra también los axiomas para cada una de los esquemas ontológicos utilizando lógica de predicado de primer orden.PALABRAS CLAVESEsquema ontológicoModelo Canónico de DatosBases de Datos Distribuidas InteligentesIntegración de Bases de DatosABSTRACTIn this abstract we will analyze-look at with the problem of the design of the "Intelligent Model for Distributed Database System".We particularly set out to design the canonical model through the ontological handling of the information. To do so,ontology is designed that allow the description of a database like a set of representative terms of their different components. In this ontology, the definitions associate classes, relations, functions, among other things, of organizations in the speech universe of the data bases, to describe their meaning, its components, restrictions, etc. The reason for using ontology is that it defines concepts and relations within a taxonomic frame, whose conceptualization is represented in a formal, legible and usable way. In previous works [14] a reference model and architecture for the integration of database the need to define an intelligent canonical model was proposed. Like continuation of these works, in this article the ontological taxonomies are described, determining the component of the model of reference for the integration of database, and the Canonical Model is designed using this ontological notion. By doing so, the process of integration between the different types of database is defined. These component data bases can be: Relational, OO, Fuzzy, Intelligent and Multimedia. Thus, the ontological scheme describes the concepts, operations and restrictions, as well as, the component database and its process of integration. In this work there are also the axioms for each one of the ontological schemes using first-order predicate logic.KEYWORDSOntological SchemeCanonical data ModelDistributed Database IntelligentDatabase Integratio

Targeting inflammasome by the inhibition of caspase-1 activity using capped mesoporous silica nanoparticles

[EN] Acute inflammation is a protective response of the body to harmful stimuli, such as pathogens or damaged cells. However, dysregulated inflammation can cause secondary damage and could thus contribute to the pathophysiology of many diseases. Inflammasomes, the macromolecular complexes responsible for caspase-1 activation, have emerged as key regulators of immune and inflammatory responses. Therefore, modulation of inflammasome activity has become an important therapeutic approach. Here we describe the design of a smart nanodevice that takes advantage of the passive targeting of nanoparticles to macrophages and enhances the therapeutic effect of caspase-1 inhibitor VX-765 in vivo. The functional hybrid systems consisted of MCM-41-based nanoparticles loaded with anti-inflammatory drug VX-765 (S2-P) and capped with poly-L-lysine, which acts as a molecular gate. S2-P activity has been evaluated in cellular and in vivo models of inflammation. The results indicated the potential advantage of using nanodevices to treat inflammatory diseases. (C) 2017 Elsevier B.V. All rights reserved.The authors wish to express their gratitude to the Spanish government (Projects MAT2015-64139-C4-1-R and SAF2014-52614-R (MINECO/FEDER)) and the Generalitat Valencia (Projects PROMETEOII/2014/061 and PROMETEOII/2014/047) for support. A.G-F. is grateful to the Spanish government for an FPU grant.García-Fernández, A.; García-Laínez, G.; Ferrandiz Manglano, ML.; Aznar, E.; Sancenón Galarza, F.; Alcaraz, MJ.; Murguía, JR.... (2017). Targeting inflammasome by the inhibition of caspase-1 activity using capped mesoporous silica nanoparticles. Journal of Controlled Release. 248:60-70. https://doi.org/10.1016/j.jconrel.2017.01.002S607024

The Bilayer Collective Properties Govern the Interaction of an HIV-1 Antibody with the Viral Membrane

Efficient engagement with the envelope glycoprotein membrane-proximal external region (MPER) results in robust blocking of viral infection by a class of broadly neutralizing antibodies (bnAbs) against human immunodeficiency virus (HIV). Developing an accommodation surface that engages with the viral lipid envelope appears to correlate with the neutralizing potency displayed by these bnAbs. The nature of the interactions established between the antibody and the lipid is nonetheless a matter of debate, with some authors arguing that anti-MPER specificity arises only under pathological conditions in autoantibodies endowed with stereospecific binding sites for phospholipids. However, bnAb-lipid interactions are often studied in systems that do not fully preserve the biophysical properties of lipid bilayers, and therefore, questions on binding specificity and the effect of collective membrane properties on the interaction are still open. Here, to evaluate the specificity of lipid interactions of an anti-MPER bnAb (4E10) in an intact membrane context, we determine quantitatively its association with lipid bilayers by means of scanning fluorescence correlation spectroscopy and all-atom molecular dynamic simulations. Our data support that 4E10 establishes electrostatic and hydrophobic interactions with the viral membrane surface and that the collective physical properties of the lipid bilayer influence 4E10 dynamics therein. We conclude that establishment of peripheral, nonspecific electrostatic interactions with the viral membrane through accommodation surfaces may assist high-affinity binding of HIV-1 MPER epitope at membrane interfaces. These findings highlight the importance of considering antibody-lipid interactions in the design of antibody-based anti-HIV strategies.</p