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Dr. Maureira-Carsalade, Nelson
Nombre de publicación
Dr. Maureira-Carsalade, Nelson
Nombre completo
Maureira Carsalade, Nelson Eduardo
Facultad
Email
nmaureira@ucsc.cl
ORCID
22 results
Research Outputs
Now showing 1 - 10 of 22
- PublicationAlpha de Cronbach y su intervalo de confianza(Arán Ediciones, 2024)
; ;Roco-Videla, Ángel ;Flores, SergioOlguín-Barraza, Mariela - PublicationMicrobiome and type 2 diabetes mellitus: The need-to-know population variability in Latin American populations(Elsevier, 2024)
; ;Flores, Sergio ;Olguin-Barraza, MarielaRoco-Videla, Ángel - PublicationAssociation between Drug Use and Perception of Mental Health in Women Diagnosed with Fibromyalgia: An Observational Study(MDPI, 2024)
;Lizama-Lefno, Andrea ;Mojica, Krystel ;Roco-Videla, Ángel ;Vargas Ruiz-Tagle, Juan Ignacio ;González-Droguett, Nelia ;Muñoz-Yánez, María Jesús ;Atenas-Núñez, Erick; Flores Carrasco, SergioBackground/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. - PublicationInvestigation on properties of raw and alkali treated novel cellulosic root fibres of zea mays for polymeric composites(Polymers, 2023)
;Kavitha, S. Anne ;Priya, R. Krishna ;Prakash-Arunachalam, Krishna ;Avudaiappan, Siva; Roco-Videla, ÁngelToday, 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. - PublicationCharacterisation of Sodium Acetate Treatment on Acacia pennata Natural Fibres(Polymers, 2023)
;Jaya-Sheeba, Kasirajan Rajam ;Retnam Krishna Priya ;Krishna Prakash Arunachalam ;Avudaiappan, Siva; Roco-Videla, ÁngelThe present study concerns the physico-chemical, structural, mechanical and thermal characterization of Acacia pennata, a natural and almost inexpensive fibre, as a potential reinforcement in polymer composites. The effect of treating the fibre with sodium acetate to increase its qualities has been seen through the use of thermogravimetric analysis, scanning electron microscope (SEM) analysis, X-ray diffraction (XRD), mechanical property tester, and Fourier transform infrared spectroscopy (FTIR). According to XRD analysis, the elimination of lignin and wax-like impurities resulted in an increase in the AP fibre’s crystalline index (79.73%). The fibre’s thermal stability was also discovered to be 365 ◦C. Tensile strength (557.58 MPa) and elongation at break both increased by 2.9% after treatment with sodium acetate. The surface nature and quality of AP fibres improved after sodium acetate treatment. It was confirmed by the reduction of chemical compositions (such as hemicellulose, lignin and pectin). Given its density, the fibre can be suggested as a reinforcement in polymer composites for light-weight applications because its lightweight property will be more useful for composite manufacturing. - PublicationExperimental and numerical investigations of laced built-up lightweight concrete encased columns subjected to cyclic axial load(Buildings, 2023)
;Divyah,Nagarajan ;Prakash, Ramaiah ;Srividhya, Sundaresan ;Avudaiappan, Siva ;Guindos, Pablo; ;Prakash-Arunachalam, Krishna ;Noroozinejad-Farsangi, EhsanRoco-Videla, ÁngelThe steel-concrete composite column comprises a steel core and surrounding concrete. The purpose of the system is to provide analysis and design techniques for a newly invented class of laced steel-concrete composite short columns for cyclic axial loads. To minimize the increasing density issues associated with nominal strength concrete and in consideration of the depletion of natural resources required to produce concrete, factory-obtained lightweight sintered fly ash aggregates with and without basalt fiber are employed. The normal-weight concrete containing basalt fiber is shown to be more ductile than any other column. The axial deformation of columns LNA and LSA at failure was found to be 3.5 mm, whereas columns LNAF and LSAF reached an axial shortening of 4.5 mm at failure. The column LSAF was found to have 5.3% more energy absorption than the LSA and 11.5% less than the column LNAF. It was observed that the rigidity of these fabricated components had been enhanced. It was found that the section configuration with a lacing system had improved confinement effects and ductility. Comparing the finite element analysis to the experimental data revealed a strong connection with numerical modeling, with a variance of around 8.77%. - PublicationImprovement of the analytical model of an energy dissipator and validation with experimental tests of a prototype(Buildings, 2023)
;Balboa-Constanzo, Esteban; ; ;Roco-Videla, Ángel ;Sanhueza-Cartes, Marcelo ;Arias-Guzmán, PatricioCanales, CristianAn 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. - PublicationAsociación estadística entre marcadores genéticos y adicción a la comida: Consideraciones metodológicas(Arán Ediciones, 2023)
; ;Roco-Videla, Ángel ;Flores, SergioOlguín-Barraza, Mariela - PublicationApplication of the response surface methodology for yield optimization in maize (Zea mays L.)(Universidad del Zulia, 2023)
; ;Montaña, Román ;Roco-Videla, Ángel ;Nieves, AnaFlores, SergioThe objective of this study was based on the application of the response surface methodology (RSM) for yield optimization in maize (Zea mays L.). The hybrid INIA SQ-1 was used, and the Response Surface Methodology was used using the Box-Behnken design (DBB), with which the following factors were evaluated: plant density, nitrogen (N) dose and phosphorus (P) dose at three levels each; for the optimization of the response variables: “yield” (kg.ha-1) and the “number of grains per square meter” (g.m2). The response surface method provided a statistically validated predictive model, which through adjustments was adapted to an established optimization process. For the variable “yield”, a maximum response was found with the application of 150 Kg.ha-1 of N and 90 kg.ha-1 of P. In relation to the number of grains per square meter (g.m2), the optimum was obtained using 75,000 plants.ha-1 and an applied dose of 150 kg.ha-1.
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