Study of non-linear viscoelastic behavior of the human red blood cell

The non-linear behavior of human erythrocytes subjected to shear stress was analyzed using data series from the Erythrocyte Rheometer and a theoretical model was developed. Linear behavior was eliminated by means of a slot filter and a sixth order Savisky-Golay filter was applied to the resulting time series that allows the elimination of any possible white noise in the data. A fast Fourier transform was performed on the processed data, which resulted in a series of frequency dominant peaks. Results suggest the presence of a non-linear quadratic term in the Kelvin-Voigt phenomenological model. The correlation dimension studied through recurrence quantification analysis gave C2=2.58. Results suggest that the underlying dynamics is the same in each RBC sample corresponding to healthy donors

Lógica difusa en modelos agropecuarios

El presente trabajo trata sobre modelos de lógica difusa para la toma de decisiones en contexto de incertidumbre aplicados a la actividad agrícola. El estudio de esta temática aplicada al sector agropecuario, surgió por la importancia de contar con un modelo que facilite la selección de alternativas óptimas al productor, dado que los modelos basados en la teoría de conjuntos borrosos permiten describir y formalizar la realidad utilizando elementos flexibles que interpretan las leyes que rigen el comportamiento humano y las relaciones con el medioambiente. Se analiza la Borrosidad en los Términos Independientes, dado que existe incerteza en la rotación de los cultivos. Se utiliza el modelo de lógica difusa de Delgado, Verdegay y Vila (1989). Con el modelo de Verdegay (1989)se analaiza la borrosidad en los coeficientes del funcional.The present work deals with models of fuzzy logic for decision making in the context of uncertainty applied to agricultural activity. Application of this thematic to the agricultural sector, arose for the importance of making the selection of optimal alternatives to the producer, since models based on fuzzy logic sets allow to describe and formalize the reality using flexible elements that Interpret the laws that govern human behavior and relationships with the environment. Blurring is analyzed in the Independent terms, since there is uncertainty in the rotation of the crops. The fuzzy logic model of Delgado, Verdegay and Vila (1989) is used. The Verdegay (1989) model analyzes the blurring of the functional coefficients.Sociedad Argentina de Informática e Investigación Operativ

Using evaluation grids for scientific publications. A method for objectifying the evaluation process

La presentación de trabajos científicos a través de un informe requiere de un armado que podemos llamar “anatomía de un informe” y una dinámica en su interior a la que consideramos “la fisiología del informe” para que tenga validez y credibilidad, pero ¿cómo se evalúan los trabajos científicos presentados en nuestros congresos? ¿Cuáles son los criterios para determinar que un trabajo sea aceptado o no? El Comité de Investigación de la AAOT elaboró las grillas de evaluación. El objetivo de publicar las grillas es poder contar con una herramienta objetiva de valoración cualitativa y cuantitativa de todos los trabajos presentados en sus diferentes géneros, que podrá ser utilizada por los evaluadores de trabajos como elemento de feedback y como elemento de evaluación objetiva, y por los autores como guía para el armado del informe de su trabajo de investigación.For validity and credibility purposes, the presentation of scientific publications in a report form requires a certain layout that we could call the “anatomy of the report”, as well as the dynamics of it, considered the “physiology of the report”. But how are conference scientific publications evaluated? What are the criteria used determine whether a report is accepted or not? The Research Committee at the AAOT developed evaluation with the aim of publishing them to have an objective tool for the qualitative and quantitative evaluation of all types of publications submitted. These grids could be used by evaluators to present their feedback, as well as an objective evaluation tool. Authors could used them as a guide to prepare the report of their research work.Facultad de Humanidades y Ciencias de la Educació

A preliminary study of the effect of anesthetic agents on the rheological parameters of glycated erythrocytes

Este trabajo presenta un estudio preliminar de los efectos de los anestésicos propofol, remifentanilo y bromuro de vecuronio sobre las propiedades reológicas de eritrocitos glicados in vitro, modelizando la glicación por hiperglucemia observada en la diabetes. Se determinaron los parámetros viscoelásticos y de cinética de agregación de los eritrocitos utilizando un reómetro eritrocitario y un agregómetro de chip óptico desarrollados en nuestro laboratorio. Los resultados mostraron alteraciones significativas en la viscosidad superficial de membrana, el módulo elástico y el índice de deformabilidad eritrocitaria para los distintos anestésicos estudiados. También los parámetros de cinética de agregación mostraron diferente tipo de alteraciones por efecto de los anestésicos. Este estudio preliminar sugiere que el uso de estos anestésicos en pacientes diabéticos podría inducir alteraciones hemorreológicas que perturben la microcirculación. Por tal motivo, se recomienda profundizar estas investigaciones a fin de prevenir complicaciones en procedimientos quirúrgicos.This paper presents a preliminary study of the effects of the anesthetics propofol, remifentanil, and vecuronium bromide on the rheological properties of glycated erythrocytes in vitro, modeling the glycation by hyperglycemia observed in diabetes. Viscoelastic and aggregation kinetic parameters of erythrocytes were determined using an erythrocyte rheometer and an optical chip aggregometer developed in our laboratory. The results showed significant alterations in the membrane surface viscosity, the elastic modulus, and the erythrocyte deformability index for the different anesthetics studied. Also, the kinetics aggregation parameters showed different types of alterations due to the effect of anesthetics. This preliminary study suggests that the use of these anesthetics in diabetic patients could induce hemorheological alterations that disturb the microcirculation. For this reason, it is recommended to deepen these investigations to prevent complications in surgical procedures.Fil: Batista Da Silva, Marcus Vinícius. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Castellini, Horacio Virginio. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; ArgentinaFil: Alet, Nicolás Alberto. Universidad Nacional de Rosario. Facultad de Ciencias Médicas; Argentina. Hospital de Emergencias Clemente Álvarez; ArgentinaFil: Riquelme, Bibiana Doris. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Alet, Analía Inés. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmaceuticas. Departamento de Química y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentin

Study of non-linear viscoelastic behavior of the human red blood cell

The non-linear behavior of human erythrocytes subjected to shear stress was analyzed using data series from the Erythrocyte Rheometer and a theoretical model was developed. Linear behavior was eliminated by means of a slot filter and a sixth order Savisky-Golay filter was applied to the resulting time series that allows the elimination of any possible white noise in the data. A fast Fourier transform was performed on the processed data, which resulted in a series of frequency dominant peaks. Results suggest the presence of a non-linear quadratic term in the Kelvin- Voigt phenomenological model. The correlation dimension studied through recurrence quantification analysis gave C2=(2.58±0.08). Results suggest that the underlying dynamics is the same in each RBC sample corresponding to healthy donors.Fil: Castellini, Horacio V. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura. Departamento de Física; Argentina.Fil: Riquelme, Bibiana Doris. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina

Alterations of the erythrocyte membrane by in vitro action of Trichinella spiralis muscle larvae

The complex life cycle of Trichinella spiralis includes the migration of newborn larvae through the bloodstream to their encystment in muscle. The parasite establishes an intimate contact with the erythrocytes of the host both during the migration of the newborn larvae and when encysting, as this parasite causes intense vascularization in the muscle cell. The goal of this work was to study the effects of various concentrations of T. spiralis muscle larvae (ML) on erythrocyte membranes. The treatment was performed by incubating human erythrocytes with equal volume of different concentrations of ML for 30 minutes, with controlled agitation (37°C). The control erythrocytes (with no contact with the larvae) were incubated in the same way with an equal volume of physiological solution. To evaluate the alterations to the erythrocytes by the action of the larvae and in the respective controls, an Erythrocyte Rheometer and a Digital Image Analysis technique were used. The results indicated that when the larval concentration was higher, the aggregation and erythrocyte membrane alterations were also higher. Also, the erythrocyte deformability index and the erythrocyte elasticity increased. The values of isolated cell coefficient varied from 0.51 in the treatment with 100 larvae/ml to 0.91 in the incubation with 1000 larvae/ml. This experiment shows that T. spiralis muscle larvae affect significantly the red blood cell aggregation and the erythrocyte viscoelastic properties.Fil: Ponce de León, Patricia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Bellini, Mariana. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Castellini, Horacio V. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina.Fil: Riquelme, Bibiana Doris. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Física Rosario (IFIR-CONICET); Argentina