RESUMO
Aging is generally associated with a decline in important cognitive functions that can be observed in EEG. Physical activity in older adults should be considered one of the main strategies to promote health and prevent disease in the elderly. The present study aimed to systematically review studies of EEG activity and cognitive function changes associated with physical activity in older adults. Records from PubMed, Scopus, and EBSCO databases were searched and, following the PRISMA guidelines, nine studies were included in the present systematic review. A risk of bias assessment was performed using the National Institute of Health Quality Assessment Tool for Case-control Studies instrument. The studies analyzed used two main strategies to determine the effects of physical activity on cognition and EEG: (1) multiscale entropy and power frequencies; and (2) event-related potentials. In terms of EEG activity, it can be concluded that exercise-induced neuroplasticity underlies improvements in cognitive function in healthy older adults.
RESUMO
Two-phase anaerobic systems are being increasingly implemented for the treatment of both sewage sludge and organic fraction of municipal solid waste. Despite the good amount of mathematical models in anaerobic digestion, few have been applied in two-phase systems. In this study, a three-reaction mechanistic model has been developed, implemented and validated by using experimental data from a long-term anaerobic two-phase (TPAD) digester treating sewage sludge. A sensitivity analysis shows that the most influential parameters of the model are the ones related to the hydrolysis reaction and the activity of methanogens in the thermophilic reactor. The calibration procedure highlights a noticeable growth rate of the thermophilic methanogens throughout the evaluation period. Overall, all the measured variables are properly predicted by the model during both the calibration and the cross-validation periods. The model's representation of the organic matter behaviour is quite good. The most important disagreements are observed for the biogas production especially during the validation period. The whole application procedure underlines the ability of the model to properly predict the behaviour of this bioprocess.
Assuntos
Modelos Teóricos , Esgotos , Gerenciamento de Resíduos , Anaerobiose , Reatores BiológicosRESUMO
A process configuration combining thermal hydrolysis (TH) and anaerobic digestion (AD) of sludge has been studied with the objective of analysing the feasibility of the technology for full scale installations. The study has been performed through pilot scale experiments and energy integration considerations, and a scheme of the most profitable option is presented: thermal hydrolysis unit fed with 7 percent total solids (TS) secondary sludge, anaerobic digestion of the hydrolysed sludge together with fresh primary sludge, and a cogeneration unit to produce green electricity and provide hot steam for the thermal hydrolysis process. From a technical and practical point of view, the process scheme proposed is considered to be feasible. Based on the results of the pilot plant performance and the laboratory studies, the process has proven to operate successfully at a concentration of 7-8 percent TS. After the thermal hydrolysis, sludge viscosity becomes radically smaller, and this favours the digesters mixing and performance (40 percent more biogas can be obtained in nearly half the residence time compared to the conventional digestion). From an economic point of view, the key factors in the energy balance are: the recovery of heat from hot streams, and the concentration of sludge. The article presents the main energy integration schemes and defines the most profitable one: an energetically self-sufficient process, with a cogeneration unit. The scheme proposed has proven to need no additional energy input for the sludge hydrolysis, generates more that 1 MW green electricity (246 kW surplus with respect to the conventional process), and produces 58 percent less volume of Class A biowaste. The study and balances here presented set the basis for the scale-up to a demonstration plant (hydrolysis + anaerobic digestion + cogeneration unit).
Assuntos
Digestão Anaeróbia , Fontes Geradoras de Energia/análise , Fontes Geradoras de Energia/economia , Fontes Geradoras de Energia/métodos , Tratamento de Lodos/economia , Tratamento de Lodos/métodos , Biodegradação Ambiental , Biocombustíveis/métodos , HidróliseRESUMO
Introducción: en la Antigua Grecia ya se conocía la enfermedad denominada cáncer y sus avances habían progresado notablemente, sin embargo, Hipócrates sin duda alguna el más grande de los médicos de la antigüedad, fue quien designó a esta extraña enfermedad. Dentro de este contexto histórico surge el término melanoma maligno (MM), entidad de comportamiento biológico incierto, de futuro impredecible y que varía desde la regresión espontánea hasta la rápida progresión y muerte.Objetivos: revisar retrospectivamente el archivo del Departamento de Patología del Hospital de Especialidades del Centro Médico Nacional, "M. Ávila Camacho", identificando los casos de MM, durante los años 1990 a 1994, con fines estadísticos para establecer bases para otros estudios futuros de tipo analíticos.Resultados: se detectaron 51 casos de MM en el periodo estudiado, con predominio en la quinta y sexta décadas de la vida, sin tendencia con respecto al sexo; su localización más frecuente es en los miembros inferiores y sitios no expuestos al sol, Los factores pronósticos más importantes son los niveles Clark y Breslow, así como la presencia o ausencia de metástasis.Se concluyó que el MM no es una patología rara en nuestro medio, que las variables epidemiológicas y parámetros clínicos e histopatológicos del presente estudio concuerdan con lo reportado en grandes series caucásicas y norteamericanas, y que se requieren estudios longitudinales a largo plazo de cohortes para evaluar otros parámetros relevantes como eficacia terapéutica con los manejos habituales, supervivencia, correlación de factores pronósticos, tipo de tratamiento, y pronóstico.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Estatísticas Hospitalares , Melanoma/epidemiologia , Melanoma/fisiopatologiaRESUMO
Se informa el caso de una niña de 7 años de edad, que desde el primer año presenta enterorragia y se llega al diagnóstico de displasia vascular del colon izquierdo, por medio de exámenes radiográficos, endoscópicos e histológicos. Se hace énfasis en la infrecuencia de este padecimiento, así como en su localización (colon izquierdo)