35 research outputs found

    Robust Estimation for a CSTR Using a High Order Sliding Mode Observer and an Observer-Based Estimator

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    This paper presents an estimation structure for a continuous stirred-tank reactor, which is comprised of a sliding mode observer-based estimator coupled with a high-order sliding-mode observer. The whole scheme allows the robust estimation of the state and some parameters, specifically the concentration of the reactive mass, the heat of reaction and the global coefficient of heat transfer, by measuring the temperature inside the reactor and the temperature inside the jacket. In order to verify the results, the convergence proof of the proposed structure is done, and numerical simulations are presented with noiseless and noisy measurements, suggesting the applicability of the posed approach.ITESO, A.C.Universidad Nacional de Colombi

    Estimación de estado e incertidumbre en un CSTR mediante Observador Asintótico y modos deslizantes de alto orden

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    En este artículo se propone una estructura de estimación de estado para un Reactor de Tanque Agitado en Continuo (CSTR), mediante un Observador Asintótico, conjuntamente con un estimador de perturbaciones basado en un algoritmo de modos deslizantes de alto orden, tipo Super Twisting Generalizado. El esquema de estimación propuesto permite la reconstrucción asintótica de la concentración en el reactor, con base en la medición de la temperatura al interior del mismo y de la chaqueta, en la presencia de cambios en el coeficiente global de intercambio de calor UA, la constante de frecuencia k_0 de la ecuación de Arrhenius y la energía de activación E. Adicionalmente, la estructura es capaz de estimar UA y el término k_0 e^(-E/RT) de la cinética. Las propiedades del esquema propuesto se demuestran matemáticamente y a través de simulaciones.Universidad Nacional de ColombiaCinvesta

    Robust Estimation for a CSTR Using a High Order Sliding Mode Observer and an Observer-Based Estimator

    Get PDF
    This paper presents an estimation structure for a continuous stirred-tank reactor, which is comprised of a sliding mode observer-based estimator coupled with a high-order sliding-mode observer. The whole scheme allows the robust estimation of the state and some parameters, specifically the concentration of the reactive mass, the heat of reaction and the global coefficient of heat transfer, by measuring the temperature inside the reactor and the temperature inside the jacket. In order to verify the results, the convergence proof of the proposed structure is done, and numerical simulations are presented with noiseless and noisy measurements, suggesting the applicability of the posed approach.ITESO, A.C.Universidad Nacional de Colombi

    A Robust Extended State Observer for the Estimation of Concentration and Kinetics in a CSTR

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    This paper presents a state estimation structure for a Continuous Stirred Tank Reactor (CSTR), by means of an Asymptotic Observer jointly with a disturbance high order sliding mode-based estimator. The proposed estimation scheme allows the asymptotic reconstruction of the concentration inside the reactor based on the measures of the temperature inside the reactor and the temperature inside the jacket, in presence of changes in the global coefficient of heat transfer UA, the Arrhenius constant k0 and the activation energy E. Additionally, the structure is able to estimate UA and the kinetics term k0e−ERT. The properties of the proposed scheme are proved mathematically and verified through numerical simulations.ITESO, A.C.CINVESTAV-IP

    Aggression and empathyin a group of children diagnosed with oppositional defiant disorder

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    ABSTRACT: This study aimed to explore the relationships between the levels of aggression (physical, verbal, anger and hostility) and empathy in a group of school children between 7 and 11 years old in the city of Medellin (Colombia), diagnosed Oppositional Defiant Disorder. A reduced version of the Buss-Perry Aggression Questionnaire in Spanish was used to assess aggression; and a test about the type of stare and the Interpersonal Reactivity Index were administered to assess empathy. The results indicated a higher ranking on physical aggression in men in relation to women. It was found an existing relationship between aggression and some empathy levels (direct, as in the case of the number of success in the type of stare test, and opposite, with the number of errors in the same test); both relationships were significant.RESUMEN: El objetivo del trabajo fue explorar las relaciones entre los niveles de agresión (física, verbal, ira y hostilidad) y empatía en un grupo de niños y niñas escolares entre los 7 y 11 años de edad en la ciudad de Medellín (Colombia) con diagnóstico de Trastorno Negativista Desafiante. Para evaluar la agresión se utilizó la versión reducida del cuestionario AQ de Buss y Perry en idioma español, y para la empatía se aplicó el test de la mirada y el Interpersonal Reactivity Index. Los resultados indicaron mayores puntuaciones en agresión física en los varones que en relación con las mujeres. Se encontró que existe una relación entre el total de agresión y algunos niveles de empatía (directa en el caso del número de aciertos en el test de la mirada e inversa con los desaciertos del mismo); ambas relaciones fueron significativas

    Perfis de saúde em pacientes com doenças crônicas numa instituição de saúde de alta complexidade

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    Objective: to describe the different profiles in terms of health-related quality of life found in patients with chronic diseases in a high-complexity health institution. Methodology: cross-sectional descriptive study that evaluated the health-related quality of life through the EQ-5D instrument, in patients with chronic diseases that consulted Internal Medicine and its subspecialties in the outpatient service of a highly-complexity health institution in the city of Medellin, during the year 2017. Results: 158 patients between the ages 46-68 (an average of 58-year-old) were surveyed. A total of 117 patients (74.1%) were female. The time of evolution from the age when the diagnostic was run to the actual age of the patient when surveyed was 8.7 years. The general health status of the patients from Endocrinology and Rheumatology was found to be of 80 points, being the feelings of “pain or discomfort” and “anxiety or depression” the ones that most affected the quality of life Additionally, in patients with infectious pathologies the general health status was the lowest (62.5); the most common factor was “pain or discomfort). Conclusions: it is evident that there is greater alteration in the variables of the EQ-5D of “pain or discomfort” and “anxiety or depression” in the general population, as well as in the females and the areas of Endocrinology and Rheumatology.Objetivo: describir los diferentes perfiles, en términos de calidad de vida relacionada con la salud, en pacientes con enfermedades crónicas en una institución de salud de alta complejidad. Metodología: estudio transversal descriptivo. Se evaluó la calidad de vida relacionada con la salud mediante el instrumento EQ-5D en pacientes con enfermedades crónicas que consultaron a medicina interna y sus subespecialidades, en el servicio de consulta externa de una institución de salud de alta complejidad de la ciudad de Medellín durante el año 2017. Resultados: fueron encuestados 158 pacientes. La mediana de la edad fue 58 (46-68) años. El tiempo aproximado de evolución entre la edad de realización del diagnóstico principal y la edad del paciente al momento de la encuesta fue de 8.7 años, un total de 117 pacientes (74.1%) eran de sexo femenino. El estado de salud general de los pacientes de endocrinología y reumatología fue de 80 puntos, siendo los factores que afectaron la calidad de vida los denominados “dolor o malestar” y “ansiedad o depresión”. Además, en los pacientes con patologías infecciosas el estado de salud general fue el más bajo, 62.5, donde el factor “dolor o malestar” fue el más común. Conclusiones: se identifica mayor alteración en las variables del EQ-5D de “dolor o malestar” y “ansiedad o depresión” en la población general, así mismo, cuando se trata del sexo femenino y de las áreas de endocrinología y reumatología.Objetivo: descrever os diferentes perfis, em termos de qualidade de vida relacionada com a saúde, em pacientes com doenças crônicas numa instituição de saúde de alta complexidade. Metodologia: estudo transversal descritivo. Se avaliou a qualidade de vida relacionada com a saúde mediante o instrumento EQ-5D em pacientes com doenças crônicas que consultaram a medicina interna e suas subespecialidades, no serviço de consulta externa de uma instituição de saúde de alta complexidade da cidade de Medellín durante o ano 2017. Resultados: foram entrevistados 158 pacientes. A média de idade foi 58 (46-68) anos. O tempo aproximado de evolução entre a idade de realização do diagnóstico principal e a idade do paciente ao momento da enquete foi de 8.7 anos, um total de 117 pacientes (74.1%) eram de sexo feminino. O estado de saúde geral dos pacientes de endocrinologia e reumatologia foi de 80 pontos, sendo os fatores que afetaram a qualidade de vida os denominados “dores ou mal-estar” e “ansiedade ou depressão”. Ademais, nos pacientes com patologias infecciosas o estado de saúde geral foi o mais baixo, 62.5, donde o fator “dor ou mal-estar” foi o mais comum. Conclusões: se identifica maior alteração nas variáveis de EQ-5D de “dor ou mal-estar” e “ansiedade ou depressão” na população geral, assim mesmo, quando se trata do sexo feminino e das áreas de endocrinologia e reumatologia

    Research of effectiveness and approval criteria for treatments with medications for patients with cancer: a review

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    Several malignant disorders of human tissues affect a large proportion of people in Colombia and worldwide, which has led to an increase in pharmacological treatments for these diseases, without the real benefit being clear to the patients who receive them. Furthermore, there are doubts about the quality of the evidence on which the institutions that support anticancer treatments with medications are based, such as the Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Our objective was to know how efficacy studies are carried out and how treatments with medications offered to people with cancer are approved. A narrative review was carried out, which was based on the formulation of questions that guided the development of the topics that were included. The search strategy was done in PubMed in a structured but non-systematic way. Articles published in english and spanish were included, without restriction by publication date

    Evaluation and management of cardiovascualr risk in VIH infection : Expert consensus of ACIN (Colombian Association of Infectious Diseases)

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    Los pacientes con infección por VIH tienen una mayor incidencia de eventos cardiovasculares en comparación con la población general; los factores que contribuyen al incremento del riesgo de eventos cardiovasculares son la prevalencia de factores de riesgo cardiovascular tradicionales (FRCV), la infección por VIH que condiciona tanto un proceso de inflamación crónica como alteración de la función endotelial y la exposición a los antirretrovirales. Los factores que deben ser objeto de intervención son los FRCV tradicionales, en especial la alta tasa de fumadores entre este grupo de pacientes, la tamización y tratamiento de HTA, el síndrome metabólico y el acceso temprano a la terapia antirretroviral con medicamentos con mayor perfil de seguridad . Esta guía pretende proveer información y recomendaciones en el ámbito nacional acerca de la relación entre la infección por VIH/SIDA (Síndrome de Inmunodeficiencia Adquirida), uso de antirretrovirales y riesgo cardiovascular.Q1Artículo original73-91Patients with VIH infection have greater risk for cardiovascular diseases compared to general population. Risk factors that increase the frequency of cardiovascular events are: presence of cardiovascular traditional risk factors, chronic inflammation by HIV that impairs endothelial function and the exposure to antiretrovirals. The factors that should be the target for intervention are the traditional know cardiovascular factors such, especially high rate of smokers, screening and treatment for hypertension, metabolic syndrome and early access to HAART. The present guidelines provides information about the use of antiretrovirals in patients with HIV and its relation with cardiovascular risk

    Nonsurgical periodontal therapy

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    ABSTRACT: In the treatment of periodontal diseases, we can rely on nonsurgical periodontal therapy, which has been scientifically proven as its effectiveness has been recognized. The main objective of this article is to demonstrate the usefulness of nonsurgical periodontal therapy, as evidenced in several studies that serve as guidelines, as well as microbiological aspects, effects on tissues and the importance of maintenance therapy after treatment completion. Methods: a review was conducted in order to revise this topic considering key periodontal concepts as a guideline. Results: nonsurgical periodontal therapy (NSPT) is a procedure that cannot and should not be carried out in a few sessions; the time required for its completion is extended as necessary in order to achieve cleaning and adjustment of the roots as completely as possible. Conclusions: Several authors have reported that reduction of microbiota remains between 14 and 180 days after therapy. This explains the regular periodontal maintenance appointments. They also indicate that the critical aspect of this therapy is not the choice between a surgical or a nonsurgical procedure, but a detailed and thorough cleaning by the dental professional and the good level of oral hygiene achieved by the patient.RESUMEN: En el tratamiento de las enfermedades periodontales contamos con la terapia periodontal no quirúrgica, la cual ha sido avalada científicamente mostrando su efectividad. El principal objetivo de este artículo es demostrar la efectividad de la terapia periodontal no quirúrgica evidenciada en múltiples estudios con relación a las indicaciones, aspectos microbiológicos, efectos en los tejidos y la importancia de la terapia de mantenimiento una vez finalizado el tratamiento. Métodos: se hizo una revisión con relación al tema en los últimos años teniendo como patrón los conceptos clave periodontales. Resultados: la terapia periodontal no quirúrgica (TPNQ) no es un procedimiento que pueda y deba realizarse en un corto tiempo y en pocas citas, el tiempo para su ejecución se amplía lo necesario en especial para lograr una limpieza y regularización de las raíces lo más completa posible. Conclusión: varios autores reportan que la reducción de la microbiota se mantuvo entre 14 y 180 días, luego de la terapia, esto justifica las citas periódicas de mantenimiento periodontal y estos señalan que el aspecto crítico de la terapia no es la escogencia entre un procedimiento quirúrgico o no quirúrgico, sino la limpieza detallada y completa por el profesional y el buen nivel de higiene bucal por parte del paciente
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