Research Outputs

Now showing 1 - 10 of 22
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El papel de la dieta en interacción multicomponente para personas con fibromialgia, un desafío vigente

2024, Dr. Maureira-Carsalade, Nelson, Roco-Videla, Ángel, Lizama-Lefno, Andrea

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Microbiome and type 2 diabetes mellitus: The need-to-know population variability in Latin American populations

2024, Dr. Maureira-Carsalade, Nelson, Flores, Sergio, Olguin-Barraza, Mariela, Roco-Videla, Ángel

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La importancia de la representación gráfica en las correlaciones

2023, Roco-Videla, Ángel, Landabur-Ayala, Rodrigo, Dr. Maureira-Carsalade, Nelson, Olguín-Barraza, Mariela

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Investigation on properties of raw and alkali treated novel cellulosic root fibres of zea mays for polymeric composites

2023, Kavitha, S. Anne, Priya, R. Krishna, Prakash-Arunachalam, Krishna, Avudaiappan, Siva, Dr. Maureira-Carsalade, Nelson, Roco-Videla, Ángel

Today, new materials based on natural fibres have been emerging day by day to completely eradicate plastics to favour our environmental nature. In this view, the present work is based on the extraction and characterisation of the novel root fibres of the Zea mays (Zm) plant, grown by the hydroponic method. Both the dried untreated and alkali treated root fibres are investigated using a variety of structural, morphological, thermal, elemental and mechanical tests by subjecting both the samples to p-XRD, FT-IR, SEM-EDAX, TGA-DTA, CHNS and tensile strength analyses. Thermal conductivity of the untreated and treated fibres is found using Lee’s disc experiment. From p-XRD analysis, the Crystallinity Index, Percentage Crystallinity and Crystallite size of the samples are found. FT-IR studies clarify the different vibrational groups associated with the fibre samples. SEM images show that the surface roughness increases for the chemically treated samples, such that it may be effectively utilised as reinforcement for polymeric composites. The diameter of the fibre samples is found using SEM analysis. According to the EDAX spectrum, Zm fibres in both their raw and processed forms have high levels of Carbon (C) and Oxygen (O). The TGA-DTA tests revealed that the samples of natural fibre have good thermal characteristics. CHNS studies show that Carbon content is high for these samples, which is the characteristic of many natural fibres. Chemical analysis is used to ascertain the prepared samples’ chemical makeup. It reveals that both samples have significant amounts of cellulose. The density of the fibres is found to be in the range 0.3–0.6 g/cc, which is much less than any other natural fibre. Therefore, it can be used in light weight applications. From the tensile strength analysis, physical properties such as Young’s modulus and micro-fibril angle are determined. The fibres in the roots exhibit a lower tensile strength. Thus, these fibres can be used in powdered form as reinforcement for natural rubber or epoxy composites. After examining all of its properties, it could be reasonably speculated that Zea mays root fibres can be considered as an efficient reinforcement for various matrices to produce attractive bio-composites.

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Association between Drug Use and Perception of Mental Health in Women Diagnosed with Fibromyalgia: An Observational Study

2024, Lizama-Lefno, Andrea, Mojica, Krystel, Roco-Videla, Ángel, Vargas Ruiz-Tagle, Juan Ignacio, González-Droguett, Nelia, Muñoz-Yánez, María Jesús, Atenas-Núñez, Erick, Dr. Maureira-Carsalade, Nelson, Flores Carrasco, Sergio

Background/Objectives: Fibromyalgia (FM) is a chronic syndrome characterized by widespread musculoskeletal pain, fatigue, sleep disturbances, and mental health issues. It affects approximately 1.78% of the general population; an estimated 4:1 ratio between women and men is observed. It significantly impacts quality of life and carries both clinical and social stigma. This study aims to evaluate the relationship between drug use and mental health in female patients with fibromyalgia. Methods: This study is prospective, observational, and cross-sectional. A questionnaire was administered to 544 subjects, achieving a representative sample size from a population of 800,000 subjects by using an algorithm for proportion estimation with a known sampling frame. The selection was non-random, making the sampling non-probabilistic. Logistic regression models were applied to assess the effect of drug use on perception of mental health; presence of symptoms such as comprehension and memory problems, insomnia, depression, and anxiety; and severity of cognitive symptoms and non-restorative sleep. To quantify the impact, odds ratios and confidence intervals have been observed. Results: The findings indicate the non-recommended use of medications and reveal the ineffectiveness and adverse effects of drug interactions on mental health. The use of benzodiazepines and sedative-hypnotics is significantly associated with a negative perception of mental health. Benzodiazepines do not improve symptoms or significantly reduce their severity. SSRI antidepressants do not enhance mental health perception; however, when used exclusively, they are effective in reducing the severity, but not the prevalence, of cognitive symptoms. Conclusions: The results highlight the complexity of pharmacological management in FM and raise concerns about the inappropriate use of ineffective or counterproductive drug interactions affecting patients’ mental health. They underscore the need for multidisciplinary and personalized strategies that include close and careful monitoring, as well as the simultaneous use of non-pharmacological treatments that have demonstrated evidence in improving quality of life without negatively affecting mental health, such as patient education, psychological therapy, physiotherapy, and mindfulness.

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Improvement of the analytical model of an energy dissipator and validation with experimental tests of a prototype

2023, Balboa-Constanzo, Esteban, Dr. Maureira-Carsalade, Nelson, Dr. Sanhueza-Espinoza, Frank, Roco-Videla, Ángel, Sanhueza-Cartes, Marcelo, Arias-Guzmán, Patricio, Canales, Cristian

An improved numerical formulation for a self-centering frictional damper is presented. This was experimentally validated through quasi-static tests carried out on a steel-made prototype of the damper. Its design is ad hoc for implementation in the seismic protection of industrial storage racks. The conceptual model of the device was adjusted to the prototype built. The formulation of the analytical model, a parametric analysis of it, and the validation with experimental results are presented. The improvement of the model presented here explicitly considers elements included in the prototype, such as a system of load transmission rings and the friction between all of the components that slide or rotate relatively. In the experimental validation, the parameters of the improved model were determined. The numerical predictions for the improved model were contrasted with those obtained with the original one and with the experimental results. This demonstrates that the improvement leads to a better adjustment of the numerical predictions concerning the experimental measurements, which is useful for nonlinear analysis. The device withstood forces of considerable magnitude in addition to dissipating enough energy per load–unload cycle to be effective in the seismic protection of industrial storage racks.

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A comprehensive review on recycling of construction demolition waste in concrete

2023, Herbert Sinduja Joseph, Thamilselvi Pachiappan, Siva Avudaiappan, Dr. Maureira-Carsalade, Nelson, Roco-Videla, Ángel, Guindos, Pablo, Parra, Pablo

There have been efforts to use building demolition waste as an alternative aggregate in concrete to decrease the use of natural resources for construction. The World Green Building Council estimates that the construction industry is responsible for more than 50% of all material extracted globally and that construction and demolition waste makes up 35% of global landfills. As a result, incorporating recycled aggregate (RA) in concrete production is a prudent course of action to reduce the environmental impact. This study reviews prior research on using recycled aggregate instead of conventional ingredients in concrete. The composition and morphology of different types of RA, the behavior of RA in fresh and hardened states, keyword co-occurrence and evolution analysis, and the various additives used to enhance the inferior properties of RA are discussed. The RA showed different physical properties when compared with natural aggregate. However, the addition of pozzolanic materials and various pretreatment techniques is desirable for improving the inferior properties of RA. While building waste has been utilized as a substitute for fine and coarse aggregate, prior research has demonstrated that a modified mixing approach, an adequate mixing proportion, and the optimum replacement of cementitious materials are necessary. Based on the review, the recommendation is to use RA at a replacement level of up to 30% and the addition of precoated and pozzolanic materials as a treatment to provide concrete with adequate workability, strength, and durability for structural applications.

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Alpha de Cronbach y su intervalo de confianza

2024, Dr. Maureira-Carsalade, Nelson, Roco-Videla, Ángel, Flores, Sergio, Olguín-Barraza, Mariela

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Prevalencia del haplotipo de riesgo GA de los polimorfismos rs1554483 y rs4864548 del gen CLOCK asociados a la obesidad y el sobrepeso en 26 poblaciones

2023, Flores, Sergio, Roco-Videla, Ángel, Olguín-Barraza, Mariela, Dr. Maureira-Carsalade, Nelson

Introducción: el haplotipo GA de los polimorfismos rs1554483 y rs4864548 se ha asociado con componentes del síndrome metabólico como la hipertensión arterial y los niveles de triglicéridos. Sus portadores presentan un riesgo de obesidad 1,5 veces mayor que el resto de la población. Metodología: se obtuvieron los SNP rs1554483 y rs4864548 de 2504 individuos desde la base de datos “1000genomes phase 3”. Los datos se agruparon en cinco macropoblaciones (África, Asia Oriental, Asia Meridional, Europa y Latinoamérica) cubriendo un total de 26 poblaciones. Se analizaron las diferencias en la frecuencia del haplotipo entre las macropoblaciones y las poblaciones, para lo cual se utilizó el estadístico F de Fisher. Resultados: la macropoblación de África presentó la menor frecuencia (17,9 %) y la del Este de Asia la mayor (57,4 %). Dentro de las poblaciones existe una relativa homogeneidad en las frecuencias, excepto en el caso de las que componen la macropoblación de Latinoamérica, donde la población peruana de Lima y la puertorriqueña presentan frecuencias mucho mayores que el resto. Conclusiones: el haplotipo GA presenta heterogeneidad entre las macropoblaciones, lo que sugiere procesos microevolutivos altamente dife- renciados entre los continentes. Se propone estudiar la asociación del haplotipo GA con otros polimorfismos, como rs3749474, rs11932595 y rs6859524, que también se han asociado con el riesgo de obesidad y factores asociados al síndrome metabólico.

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¿Cómo determinar efectivamente si una serie de datos sigue una distribución normal cuando el tamaño muestral es pequeño?

2023, Roco-Videla, Ángel, Landabur-Ayala, Rodrigo, Dr. Maureira-Carsalade, Nelson, Olguin-Barraza, Mariela