Institutional Repository Universidad San Sebastián
Not a member yet
9206 research outputs found
Sort by
Viscous dynamics associated with hypoexcitation and structural disintegration in neurodegeneration via generative whole-brain modeling
No full textPublisher Copyright: © 2024 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.INTRODUCTION: Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) lack mechanistic biophysical modeling in diverse, underrepresented populations. Electroencephalography (EEG) is a high temporal resolution, cost-effective technique for studying dementia globally, but lacks mechanistic models and produces non-replicable results. METHODS: We developed a generative whole-brain model that combines EEG source-level metaconnectivity, anatomical priors, and a perturbational approach. This model was applied to Global South participants (AD, bvFTD, and healthy controls). RESULTS: Metaconnectivity outperformed pairwise connectivity and revealed more viscous dynamics in patients, with altered metaconnectivity patterns associated with multimodal disease presentation. The biophysical model showed that connectome disintegration and hypoexcitability triggered altered metaconnectivity dynamics and identified critical regions for brain stimulation. We replicated the main results in a second subset of participants for validation with unharmonized, heterogeneous recording settings. DISCUSSION: The results provide a novel agenda for developing mechanistic model-inspired characterization and therapies in clinical, translational, and computational neuroscience settings
Understanding the Role of Oxidative Stress in Platelet Alterations and Thrombosis Risk among Frail Older Adults
No full textPublisher Copyright: © 2024 by the authors.Frailty and cardiovascular diseases are increasingly prevalent in aging populations, sharing common pathological mechanisms, such as oxidative stress. The evidence shows that these factors predispose frail individuals to cardiovascular diseases but also increase the risk of thrombosis. Considering this background, this review aims to explore advances regarding the relationship between oxidative stress, platelet alterations, and cardiovascular diseases in frailty, examining the role of reactive oxygen species overproduction in platelet activation and thrombosis. The current evidence shows a bidirectional relationship between frailty and cardiovascular diseases, emphasizing how frailty not only predisposes individuals to cardiovascular diseases but also accelerates disease progression through oxidative damage and increased platelet function. Thus, oxidative stress is the central axis in the increase in platelet activation and secretion and the inadequate response to acetylsalicylic acid observed in frail people by mitochondrial mechanisms. Also, key biomarkers of oxidative stress, such as isoprostanes and derivate reactive oxygen metabolites, can be optimal predictors of cardiovascular risk and potential targets for therapeutic intervention. The potential of antioxidant therapies in mitigating oxidative stress and improving cardiovascular clinical outcomes such as platelet function is promising in frailty, although further research is necessary to establish the efficacy of these therapies. Understanding these mechanisms could prove essential in improving the health and quality of life of an aging population faced with the dual burden of frailty and cardiovascular diseases
Desarrollo y optimización de un dispositivo pasivo para la investigación de partículas plásticas en la atmósfera
No full textMagíster en Innovación en Biociencias y BioingenieríaLa contaminación por microplásticos es uno de los mayores desafíos ambientales de este siglo. Estudios recientes han detectado microplásticos en la atmósfera de áreas urbanas y remotas, lo que sugiere un posible transporte atmosférico a larga distancia y, por lo tanto, existe un interés creciente en comprender y analizar el destino, transporte y el efecto de los microplásticos atmosféricos en el medio ambiente. Esta investigación tiene como primer objetivo es optimizar y evaluar las tasas de acumulación de partículas plásticas de muestreadores pasivos de aire optimizados mediante el uso de disco de poliuretano (Puf-Disk) con diferentes densidades (0,012 y 0,020 g/cm3) en ambientes interiores y exteriores en la ciudad de Concepción durante periodos de exposición de 14 y 31 días. Esto proporcionó un gran conjunto de datos de 18 eventos de muestreo pasivo que permitió optimizar un método de muestreo de microplásticos atmosféricos. Los resultados mostraron que el uso del muestreador clásico capturo 1,25 veces más partículas en comparación con el muestreador colector, al mismo tiempo, Puf-Disk con una densidad menor acumulo 1,25 veces mayor cantidad de partículas en comparación con una densidad mayor. Posteriormente, se comparó la eficiencia de dos métodos de extracción de partículas de los Puf-Disk (manual y con baño ultrasónico), resultando el segundo ser más eficiente. Las partículas obtenidas se les realizo una caracterización física (forma, tamaño y color) mediante microscopía óptica y una caracterización química para identificar la estructura polimérica de la muestra, mediante espectroscopía infrarroja por transformada de Fourier (FTIR) y análisis con imagen Hiperespectral. Ambos métodos resultaron ser un buen complemento para la identificación química de partículas. Los hallazgos relacionados con esta investigación de tesis demostraron que la forma de partículas con mayor frecuencia corresponde a fibras de tamaño entre 0.5 a 1 mm. Además, que el 25% del total de muestras analizadas fueron de plástico, específicamente poliéster, PET, nailon, entre otros. Este estudio señala la necesidad de estudiar con certeza la existencia, el transporte y los posibles efectos que estos pueden tener en el ámbito urbano y en particular para la salud humana. Otros trabajos están en proceso para darle seguimiento.Microplastic pollution is one of the greatest environmental challenges of this century. Recent studies have detected microplastics in the atmosphere of urban and remote areas, suggesting possible long-range atmospheric transport, and therefore there is a growing interest in understanding and analyzing the fate, transport and effect of atmospheric microplastics in the environment. This research has as its first objective to optimize and evaluate the accumulation rates of plastic particles from passive air samplers optimized by using polyurethane disk (Puf-Disk) with different densities (0.012 and 0.020 g/cm3) in indoor and outdoor environments in the city of Concepción during exposure periods of 14 and 31 days. This provided a large data set of 18 passive sampling events that allowed the optimization of an atmospheric microplastics sampling method. The results showed that the use of the classical sampler captured 1.25 times more particles compared to the collector sampler, at the same time, Puf-Disk with a lower density accumulated 1.25 times more particles compared to a higher density. Subsequently, the efficiency of two methods of particle extraction from the Puf-Disk (manual and ultrasonic bath) was compared, with the latter proving to be more efficient. The particles obtained were physically characterized (shape, size and color) by optical microscopy and chemically characterized to identify the polymeric structure of the sample by Fourier transform infrared spectroscopy (FTIR) and hyperspectral imaging analysis. Both methods proved to be a good complement for the chemical identification of particles. The findings related to this thesis research showed that the most frequent particle shape corresponds to fibers of size between 0.5 to 1 mm. In addition, 25% of the total samples analyzed were plastic, specifically polyester, PET, nylon, among others. This study points out the need to study with certainty the existence, transport and possible effects that these can have in the urban environment and in particular for human health. Further work is in progress to follow up on this study
Mortalidad de fauna silvestre marina como resultado de floraciones de algas nocivas : revisión bibliográfica
Get PDFMedicina Veterinaria, Licenciado en Medicina VeterinariasLas floraciones algales nocivas (FAN), consisten en proliferaciones de fitoplancton que generan una variedad de efectos negativos. Si bien se consideran fenómenos naturales, se evidencia un aumento en la frecuencia, distribución, e intensidad a lo largo de las últimas décadas, lo cual ha fomentado el estudio de estos eventos en cuanto a sus características y el efecto que generan en los humanos, el ambiente y la fauna tanto doméstica como silvestre. El objetivo del presente trabajo fue realizar una revisión sistemática con el fin de indagar en la mortalidad de especies de fauna silvestre marina por floraciones de algas nocivas que han sido reportadas a nivel mundial, esto a través de la recopilación de información adquirida a partir de artículos científicos y documentos oficiales, conseguidos desde buscadores como PubMed, EBSCO, Scopus, ScienceDirect, Scielo, Dialnet Plus, Taylor & Francis y Google scholar. Se consideró como ventana temporal entre el año 2000 y enero de 2024. Los artículos científicos se eligieron por título y luego por resumen para verificar que cumplieran los criterios de inclusión. Se obtuvo un total de 45 artículos que reportaban la mortalidad de 113 diferentes especies de fauna marina a causa de las FAN y en cuanto a las especies de fitoplancton involucradas predominaron Karenia brevis, Alexandrium spp, Akashiwo sanguinea y Pseudo-nitzschia spp, en ese respectivo orden. La muerte a causa de toxinas predominó por sobre efectos nocivos mecánicos o depleciones de oxígeno en el océano, siendo la toxicosis por ácido domoico la de mayor significancia en términos numéricos, seguido de las intoxicaciones por saxitoxinas y brevetoxinas. Con relación a la distribución de los reportes, estos predominaron en los países de América del Norte, principalmente en Estados Unidos, también se presentaron registros de Argentina, Islas Malvinas, Chile, El Salvador, Australia, España y Filipinas.Harmful algal blooms (HABs) are proliferations of phytoplankton that generate a variety of negative effects. Although they are considered a natural phenomenon, there is an increase in frequency, distribution, and intensity over the last decades, which has encouraged the study of these events in terms of their characteristics and the effect they generate on humans. the environment and both domestic and wild fauna. The objective of this work was to carry out a systematic review to dig into the mortality of marine wildlife species due to harmful algal blooms that have been reported worldwide, through the compilation of information acquired from scientific articles. and official documents, obtained from search engines such as PubMed, EBSCO, Scopus, ScienceDirect, Scielo, Dialnet Plus, Taylor & Francis and Google scholar. The time window was considered between the year 2000 and January 2024. Scientific articles were chosen by title and then by abstract to verify that they met the inclusion criteria. A total of 45 articles were obtained that reported the mortality of 113 different species of marine fauna due to HABs and in terms of the phytoplankton species involved, Karenia brevis, Alexandrium spp, Akashiwo sanguinea and Pseudo-nitzschia spp predominated, respectively order. Death due to toxins predominated over mechanical harmful effects or oxygen depletion in the ocean, with toxicosis due to domoic acid being the most significant in numerical terms, followed by poisoning due to saxitoxins and brevetoxins. Regarding the distribution of the reports, these predominated in North American countries, mainly in the United States, records from Argentina, Falkland Islands, Chile, El Salvador, Australia, Spain and the Philippines were also included
Impacto de la educación remota de emergencia durante la pandemia Covid-19 en la práctica clínica : una mirada desde los ojos de los estudiantes
No full textMagíster en Educación Universitaria para Ciencias de la SaludAntecedentes: La pandemia de COVID-19 impulsó la transición a la Educación Remota de Emergencia (ERE), la cual carecía de las cualidades del aprendizaje presencial, especialmente en estudios de salud que requieren formación práctica y multidisciplinaria. Objetivo: Evaluar la percepción de los estudiantes de kinesiología sobre la ERE y su impacto en la práctica clínica respiratoria durante 2022. Métodos: Se realizó un estudio fenomenológico a través de entrevistas semiestructuradas con ex estudiantes de la Universidad Andrés Bello. Se exploraron sus experiencias con la ERE (2020-2021) y cómo influyó en su práctica clínica en la clínica INDISA en 2022. Se utilizó el software ATLAS.ti para el análisis cualitativo. Resultados: Los estudiantes reportaron un impacto negativo de la ERE en su preparación práctica para su internado clínico respiratorio. La falta de interacción directa con pacientes y tutores generó inseguridad y desconfianza en sus habilidades profesionales. Además, la ERE afectó su bienestar emocional, con desmotivación y ansiedad. Sin embargo, algunos valoraron la flexibilidad de la modalidad y el apoyo docente, aunque esto no compensó la falta de práctica directa. Conclusión: La ERE presento problemas y desafíos para la formación clínica en kinesiología, afectando negativamente la confianza y desempeño de los estudiantes.Background: The COVID-19 pandemic led to the transition to Emergency Remote Education (ERE), which lacked the qualities of in-person learning, especially in health studies that require practical and multidisciplinary training. Objective: To evaluate the perception of physiotherapy students regarding ERE and its impact on clinical respiratory practice during 2022. Methods: A phenomenological study was conducted through semi-structured interviews with former students of Universidad Andrés Bello. Their experiences with ERE (2020-2021) and how it influenced their clinical practice at Clínica INDISA in 2022 were explored. ATLAS.ti software was used for qualitative analysis. Results: Students reported a negative impact of the ERE on their practical preparation for their respiratory clinical practice. The lack of direct interaction with patients and tutors generated insecurity and lack of confidence in their professional skills. Additionally, ERE affected their emotional well-being, causing demotivation and stress. However, some students appreciated the flexibility of the modality and the support from instructors, although this did not compensate for the lack of direct practice. Conclusion: ERE presented challenges and issues for clinical training in kinesiology, negatively affecting students' confidence and performance
Occurrence and diffusive air-seawater exchanges of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Fildes Bay, King George Island, Antarctica
No full textPublisher Copyright: © 2023 Elsevier B.V.We report the levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in seawater and air, and the air-sea dynamics through diffusive exchange analysis in Fildes Bay, King George Island, Antarctica, between November 2019 and January 30, 2020. Hexachlorobenzene (HCB) was the most abundant compound in both air and seawater with concentrations around 39 ± 2.1 pg m−3 and 3.2 ± 2.4 pg L−1 respectively. The most abundant PCB congener was PCB 11, with a mean of 3.16 ± 3.7 pg m−3 in air and 2.0 ± 1.1 pg L−1 in seawater. The fugacity gradient estimated for the OCP compounds indicate a predominance of net atmospheric deposition for HCB, α-HCH, γ-HCH, 4,4′-DDT, 4,4′-DDE and close to equilibrium for the PeCB compound. The observed deposition of some OCs may be driven by high biodegradation rates and/or settling fluxes decreasing the concentration of these compounds in surface waters, which is supported by the capacity of microbial consortium to degrade some of these compounds. The estimated fugacity gradients for PCBs showed differences between congeners, with net volatilization predominating for PCB-9, a trend close to equilibrium for PCB congeners 11, 28, 52, 101, 118, 138, and 153, and deposition for PCB 180. Snow amplification may play an important role for less hydrophobic PCBs, with volatilization predominating after snow/glacier melting. As hydrophobicity increases, the biological pump decreases the concentration of PCBs in seawater, reversing the fugacity gradient to atmospheric deposition. This study highlights the potential impacts of climate change, through glacier retreat, on the biogeochemistry of POPs, remobilizing those compounds previously trapped within the cryosphere which in turn will transform the Antarctic cryosphere into a secondary source of the more volatile POPs in coastal areas, influenced by snow and ice melting
Five-repetition sit-to-stand test validation in adolescents and adults with intellectual disabilities
No full textPublisher Copyright: © The Author(s) 2024.This study aims to validate the five repetition sit to stand test (5R-STS) test as a measure of strength and functionality in adolescents and adults with intellectual disabilities (ID). The sample was made up of 159 subjects with ID (85 adolescents and 74 adults) of both sexes, with average age of 18.36 (5.26) years, belonging to four special educational centers from Santiago, Chile. Absolute (AHGS) and relative (RHGS) handgrip strength and countermovement jump (CMJ) were considered as muscle strength evaluation tests. The timed up and go (TUG) and agility test 4 × 10 m were considered as functional tests. Spearman and intraclass correlations, as well as Bland-Altman plots were used to establish the respective correlations. The average values obtained in the 5R-STS test (s) in adolescents were 6.55 and 7.24, while in adults they were 6.82 and 7.17 for men and women, respectively. Significant correlations (p = < 0.05) are established between the 5R-STS test with AHGS (r= -0.48) and RHGS (r= -0.54), CMJ (-0.53), 4 × 10 m test (-0.50) and TUG (-0.49), as well as in the analysis of agreement between 5R-STS and the TUG (ICC = 0.74) and agility 4 × 10 m (ICC = 0.61) tests, both in adolescents and adults of both sexes. The 5R-STS test is a valid, simple and safe tool to evaluate general and lower extremity muscle strength. Its use is suggested as a simple measure for monitoring functional capacity by professionals in educational and health contexts for the adolescent and adult population with ID
Revisita a los orígenes y comienzos del Movimiento Gremial Universitario en Chile : Reflexiones a partir del Manifiesto-Programa de 1963
No full textEl trabajo que se presenta es una introducción o reflexión en torno a los orígenes y comienzos del MG UC, a partir de la primera utilización pública de un documento que las obras más relevantes respecto al gremialismo han ignorado hasta la fecha. Se plantean preguntas exploratorias considerando el contenido del Manifiesto-Programa del Movimiento Gremial Universitario de 1963 debido, primeramente, a lo prematuro del texto, dejando en jaque las comprensiones convenidas hasta ahora, primero, de la fecha de fundación de la agrupación estudiantil, así como del rol histórico y doctrinario desempeñado por Jaime Guzmán Errázuriz en el germen mismo del organismo. Se adjunta, además, una transcripción textual del folleto hallado en la Biblioteca Nacional para futuras discusiones y estudios tanto del cuerpo universitario como de la corriente de pensamiento
Seroprevalence of pathogenic Leptospira serogroups in asymptomatic domestic dogs and cats : systematic review and meta-analysis
No full textPublisher Copyright: Copyright © 2024 Ricardo, Azócar-Aedo, Previtali and Monti.Leptospirosis is a neglected zoonotic disease transmitted by contact with the urine of animals infected with pathogenic species of the bacteria Leptospira or by contact with environments contaminated with the bacteria. Domestic dogs and cats may act as reservoirs or as sentinels of environmental contamination with leptospires, posing a public health concern. There is a great diversity of leptospires, and one common way to classify them is into serogroups that provide some information on the host species they are associated with. The aims of this study were: (1) to quantitatively summarize the overall prevalence and serogroup-specific prevalence of antibodies against pathogenic leptospires in asymptomatic dogs and cats and (2) to identify environmental and host characteristics that may affect the prevalence. Three electronic databases and the reference lists of eligible articles were screened, for epidemiological studies conducted between the years 2012–2022. We estimated overall and serogroup-specific prevalence using three-level meta-analysis models and assessed potential sources of heterogeneity by moderator analysis and meta-regression. Eighty-four studies met the inclusion criteria (dog studies 66.7%, cat studies 26.2%, and both species 7.1%). There were significant differences between dogs and cats in the overall prevalence model (P 0.05). In dogs, the prevalence of Leptospira interrogans serogroup Canicola was significantly higher than the other pathogenic serogroups (P < 0.001), while in cats there were no significant differences among serogroups (P = 0.373). Moderator analysis showed that the prevalence of L. kirschneri serogroup Grippotyphosa was significantly higher in stray/sheltered dogs than in domiciled dogs (P = 0.028). These results suggest that pathogenic serogroups associated with small mammals are circulating among asymptomatic pets and should be taken into account in the transmission cycle of leptospires, as well as in the standard MAT panel for diagnosis in dogs and cats. It also highlights the importance of including both dogs and cats as potential reservoirs when conducting eco-epidemiological studies in different geographical and ecological areas
Effectiveness of a novel multicomponent treatment in women with fibromyalgia : A randomized clinical trial
No full textPublisher Copyright: © The Author(s) 2024.Background: Multicomponent treatment is commonly used. However, there are no studies that included graded motor imagery and therapeutic neuroscience education to multicomponent treatment for patients with fibromyalgia This study aims to compare the short-term effects (at 12 weeks) of a multicomponent treatment combined with graded motor imagery and therapeutic neuroscience education versus standard treatment in patients with FM. Methods: The study was a single-blinded randomized controlled trial. Sixty-five women with a clinical diagnosis of FM were randomly allocated (1:1) into two groups. The experimental group (n = 33) received a novel multicomponent treatment combined with graded motor imagery and neuroscience education. The control group (n = 32) received a standard treatment including pharmacotherapy and standard physician education. The primary outcome was pain intensity assessed with the Numeric Pain Rating Scale (NPRS). The secondary outcomes were changes in the Fibromyalgia Impact Questionnaire (FIQ), the Pain Catastrophizing Scale (PCS), the Tampa Scale of Kinesiophobia (TSK-17), and the Pittsburgh Sleep Quality Index (PSQI) scores. All outcomes were assessed at baseline and 12 weeks. Results: All of the participants completed the trial. The between-group mean differences at 12 weeks were: NPRS-1.18 points (95% confidence interval [CI] -0.4 to -1.8; η2 = 0.47; p <.001); FIQ-16.21 points (95% CI -10.9 to -22.1; η2 = 0.58; p <.001); PCS total domain −12.5 points (95% CI -7.2 to -17.8; η2 = 0.61; p <.001); TSK-17-6.15 points (95% CI -3.5 to -8.7; η2 = 0.52; p <.001); and PSQI-2.74 points (95% CI -1.4 to 4.0; η2 = 0.54; p <.001). All differences were statistically significant in favor of the novel multicomponent treatment group and had a large effect size. Conclusions: In the short term, a novel multicomponent treatment, including graded motor imagery and neuroscience education, was an effective therapeutic intervention for improving clinical outcomes compared with standard treatment in women with FM. Additional studies are needed to support long-term clinical effectiveness in these patients.Background: Multicomponent treatment is commonly used. However, there are no studies that included graded motor imagery and therapeutic neuroscience education to multicomponent treatment for patients with fibromyalgia This study aims to compare the short-term effects (at 12 weeks) of a multicomponent treatment combined with graded motor imagery and therapeutic neuroscience education versus standard treatment in patients with FM. Methods: The study was a single-blinded randomized controlled trial. Sixty-five women with a clinical diagnosis of FM were randomly allocated (1:1) into two groups. The experimental group (n = 33) received a novel multicomponent treatment combined with graded motor imagery and neuroscience education. The control group (n = 32) received a standard treatment including pharmacotherapy and standard physician education. The primary outcome was pain intensity assessed with the Numeric Pain Rating Scale (NPRS). The secondary outcomes were changes in the Fibromyalgia Impact Questionnaire (FIQ), the Pain Catastrophizing Scale (PCS), the Tampa Scale of Kinesiophobia (TSK-17), and the Pittsburgh Sleep Quality Index (PSQI) scores. All outcomes were assessed at baseline and 12 weeks. Results: All of the participants completed the trial. The between-group mean differences at 12 weeks were: NPRS-1.18 points (95% confidence interval [CI] -0.4 to -1.8; η2 = 0.47;