1000 resultados para raquel kogan
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Biopolymer-based materials have been of particular interest as alternatives do synthetic polymers due to their low toxicity, biodegradability and biocompatibility. Among them, chitosan is one of the most studied ones and has recently been investigated for the application as solid state polymer electrolytes. Furthermore, it can serve as a host for luminescent species such as rare earth ions, giving rise to materials with increased functionality, of particular interest for electrochemical devices. In this study, we investigate chitosan based luminescent materials doped wit Eu3+ and Li+ triflate salts from the structural, photophysical and conductivity points of view. Because the host presents a broad emission band in the blue to green, while Eu3+ emits in the red, fine tuning of emission colour and/or generation of white light is possible by optimizing composition and excitation scheme. Europium lifetimes (5D0) are in the range 270 – 350 µs and quantum yields are as high as 2%. Although Li+ does not interfere with the luminescent properties, it grants ion-conducting properties to the material suggesting that a combination of both properties could be further explored in multifunctional device.
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OBJETIVO: Analisamos prevalência, intensidade e duração dos sintomas da síndrome pré-menstrual (SPM) entre as reeducandas condenadas por crimes violentos contra pessoas do presídio feminino Santa Luzia de Maceió. MÉTODOS: Foi aplicado um questionário baseado nos critérios diagnósticos para SPM presentes na Classificação Internacional de Doenças (CID-10) a 29 reeducandas. Foram avaliados os seguintes sintomas: depressão, dor nas costas, dor ou inchaço nas pernas, cefaléia, dor abdominal, mastalgia e irritabilidade. RESULTADOS: Vinte reeducandas (67%) apresentavam sintomas pré-menstruais de grave intensidade, que causavam prejuízos em suas atividades diárias, sendo caracterizadas como portadoras de SPM. Dessas, 80% relataram irritabilidade, 70% mastalgia, 66,6% cefaléia e 56,6% depressão. Dor e/ou inchaço nas pernas foram assinalados por 40%, dor abdominal por 33,3% e dor nas costas por 20%. Os sintomas duravam de dois a cinco dias em 85% das entrevistadas. Apenas 20% acreditavam que a SPM poderia ter influenciado no cometimento de seus delitos. CONCLUSÕES: A maioria das entrevistadas (67%) relatou pelo menos um sintoma de grave intensidade na fase pré-menstrual, sendo consideradas portadoras de SPM.
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Polymer electrolytes are currently the focus of much attention as potential electrolytes in electrochemical devices such as batteries, display devices and sensors. Generically, solid polymer electrolytes (SPEs) are mixtures of salts with soft polar polymers. SPEs have many advantages including high energy density, no risk of leakage, no issues related to the presence of solvent, wide electrochemical stability windows, simplified processability and light weight. With the goal of developing a new family of environmentally friendly multifunctional biohybrid materials displaying high ionic conductivity we have produced in the present work, flexible films based on different polymers or hybrids incorporating different salts. The polymer electrolytes studied here have been characterized by means of Differential Scanning Calorimetry, Thermogravimetric Analysis, X-ray diffraction, Polarized Optical Microscopy, complex impedance spectroscopy and cyclic voltammetry. An evaluation of the performance of the sample with the highest conductivity as electrolyte in all solid-state ECDs was performed.
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Gold nanorods (AuNRs) have emerged as an exceptional nanotool for a myriad of applications ranging from cancer therapy to tissue engineering. However, their surface modification with biocompatible and stabilizing biomaterials is crucial to allow their use in a biological environment. Herein, low-acyl gellan gum (GG) was used to coat AuNRs surface, taking advantage of its stabilizing, biocompatible and gelling features. The layer-by-layer based strategy implied the successive deposition of poly(acrylic acid), poly(allylamine hydrochloride) and GG, which allowed the formation of a GG hydrogel-like shell with 7 nm thickness around individual AuNRs. Stability studies in a wide range of pH and salt concentrations showed that the polysaccharide coating can prevent AuNRs aggregation. Moreover, a reversible pH-responsive feature of the nanoparticles was observed. Cytocompatibility and osteogenic ability of GG-coated AuNRs was also addressed. After 14 days of culturing within SaOS-2, an osteoblast-like cell line, in vitro studies revealed that AuNRs-GG exhibit no cytotoxicity, were internalized by the cells and localized inside lysosomes. AuNRs-GG combined with osteogenic media enhanced the mineralization capacity two-fold, as compared to cells exposed to osteogenic media alone. The proposed system has shown interesting features for osteogenesis, and further insights might be relevant for drug delivery, tissue engineering and regenerative medicine.
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This paper aims to assess the impact of environmental noise in the vicinity of primary schools and to analyze its influence in the workplace and in student performance through perceptions and objective evaluation. The subjective evaluation consisted of the application of questionnaires to students and teachers, and the objective assessment consisted of measuring in situ noise levels. The survey covered nine classes located in three primary schools. Statistical Package for Social Sciences was used for data processing and to draw conclusions. Additionally, the relationship of the difference between environmental and background noise levels of each classroom and students with difficulties in hearing the teacherâ s voice was examined. Noise levels in front of the school, the schoolyard, and the most noise-exposed classrooms (occupied and unoccupied) were measured. Indoor noise levels were much higher than World Health Organization (WHO) recommended values: LAeq,30min averaged 70.5 dB(A) in occupied classrooms, and 38.6 dB(A) in unoccupied ones. Measurements of indoor and outdoor noise suggest that noise from the outside (road, schoolyard) affects the background noise level in classrooms but in varying degrees. It was concluded that the façades most exposed to road traffic noise are subjected to values higher than 55.0 dB(A), and noise levels inside the classrooms are mainly due to the schoolyard, students, and the road traffic. The difference between background (LA95,30min) and the equivalent noise levels (LAeq,30min) in occupied classrooms was 19.2 dB(A), which shows that studentsâ activities are a significant source of classroom noise.
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Nowadays, considering the high variety of construction products, adequate material selection, based on their properties and function, becomes increasingly important. In this research, a ranking procedure developed by Czarnecki and Lukowski is applied in mortars with incorporation of phase change materials (PCM). The ranking procedure transforms experimental results of properties into one numerical value. The products can be classified according to their individual properties or even an optimized combination of different properties. The main purpose of this study was the ranking of mortars with incorporation of different contents of PCM based in different binders. Aerial lime, hydraulic lime, gypsum and cement were the binders studied. For each binder, three different mortars were developed. Reference mortars, mortars with incorporation of 40% of PCM and mortars with incorporation of 40% of PCM and 1% of fibers, were tested. Results show that the incorporation of PCM in mortars changes their global performance.
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Dissertação de mestrado em Design de Comunicação de Moda
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Tese de Doutoramento em Ciências da Literatura (Especialidade em Literatura Comparada)
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Tese de Doutoramento em Engenharia Química e Biológica
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OBJETIVOS: Avaliar as definições, métodos de avaliação e hipóteses etiológicas utilizadas em estudos longitudinais sobre consciência da doença na demência do tipo Alzheimer. MÉTODO: Pesquisa, nas bases de dados Medline, ISI, Lilacs e SciELO, de estudos longitudinais sobre consciência da doença na demência do tipo Alzheimer entre 1999 e 2009. As palavras-chave utilizadas foram: "Alzheimer", "dementia", "anosognosia", "awareness of deficit", "awareness of disease", "insight" e "longitudinal study". Os artigos examinados foram classificados conforme as hipóteses etiológicas encontradas. RESULTADOS: Os nove artigos selecionados foram divididos em duas áreas: hipóteses etiológicas biológicas e hipóteses etiológicas psicossociais. Os termos "falta de consciência dos déficits", "consciência do déficit", "insight" e "negação do déficit de memória" são utilizados nos estudos como sinônimos do termo "anosognosia", mesmo sendo, conceitualmente, diferentes. O método de avaliação mais utilizado foi o uso de questionários de discrepância entre os relatos dos pacientes e cuidadores. CONCLUSÕES: Os estudos longitudinais apresentam hipóteses etiológicas heterogêneas, além da inexistência de um padrão conceitual e metodológico de avaliação. Essas dificuldades impossibilitam a obtenção de resultados homogêneos, o que gera a necessidade de aprofundamento dos estudos na área.
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Dissertação de mestrado integrado em Engenharia Civil
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OBJETIVOS: Revisar sistematicamente desenhos de estudo, instrumentos de avaliação e fatores relacionados ao comprometimento dos domínios cognitivo e funcional da consciência do déficit em pessoas com doença de Alzheimer (DA). MÉTODO: Pesquisa nas bases de dados PubMed e ISI de estudos sobre consciência do déficit na DA publicados entre 2008 e 2013. As palavras-chave utilizadas foram: "dementia", "Alzheimer", "awareness", "awareness of memory" e "awareness of functioning", "deficits", "cognition". RESULTADOS: Os 10 artigos selecionados utilizaram os conceitos "falta de consciência do déficit", "anosognosia", "insight", "falta de consciência das dificuldades cognitivas" e "consciência limitada das deficiências". A etiologia do comprometimento da consciência do déficit foi relacionada a fatores biológicos como gravidade clínica da doença, associações neuroanatômicas, alterações neuropsiquiátricas e fatores psicológicos e sociais. O desenho de estudo mais utilizado foi o corte transversal. No domínio cognitivo, a memória e as funções executivas foram as duas principais funções investigadas. No domínio funcional, foram encontradas associações com a disfunção executiva, declínio da interação social, depressão e a influência do desempenho ocupacional. CONCLUSÕES: As distintas hipóteses etiológicas, a operacionalização variável do conceito e a falta de instrumentos de avaliação padronizados impossibilitam a obtenção de resultados homogêneos. Essas dificuldades comprometem a compreensão e a investigação dos domínios cognitivo e funcional.
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ABSTRACT Objectives To compare and discuss the objects of awareness in Alzheimer’s disease (AD): awareness of cognitive deficits, of functional activities, of social-emotional functioning and behavioral impairment. Methods A search in the PsycINFo, Pilots, PubMed/Medline and ISI electronic databases according to Prisma methodology was performed. We included studies about awareness in people with AD published between 2010 and 2015, with the combination of keywords: “Alzheimer AND awareness of deficits”, “Alzheimer AND anosognosia”, “Alzheimer AND insight”, “dementia AND awareness of deficits”, “dementia AND anosognosia”, “dementia AND insight”. The articles were categorized according to the specific object of awareness. Results Seven hundred and ten records were identified and, after application of the exclusion criteria, 191 studies were retrieved for potential use. After excluding the duplicates, 46 studies were included. Most studies assessed the cognitive domain of awareness, followed by the functional, social-emotional, and behavioral impairment domains. Memory deficits were not sufficient to explain impaired awareness in AD. Longitudinal studies did not find discrepancies between patients and caregivers’ reports, indicating that awareness is not related to cognition. Conflicting findings were observed, including the relation between awareness, mood, severity of disease, and personal characteristics. Conclusions The studies show lack of conceptual consensus and significant methodological differences. The inclusion of samples without differentiation of dementia etiology is associated to symptomatic differences, which affect awareness domains. Awareness in AD is a complex and multidimensional construct. Different objects elicit different levels of awareness.
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Relatório de estágio de mestrado em Ensino de Informática
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Dissertação de mestrado em Arqueologia