3,138 research outputs found
Extraction of Some Ellagic Tannins and Ellagic Acid from Oak Wood Chips (Quercus pyrenaica L.) in Model Wine Solutions: Effect of Time, pH, Temperature and Alcoholic Content
The subject of the present work is the study of the influence of pH, temperature, alcoholic content and time on the extraction of some individual ellagic tannins (castalagin, vescalagin, grandinin, roburin D and E) and ellagic acid from oak wood chips (Quercus pyrenaica L.) within model wine solutions. The determination of these compounds by reversed-phase high-performance liquid chromatography (HPLC), after 104 extraction days, enabled us to establish the qualitative and quantitative evolution of each component and the effect of each extraction condition on individual and total ellagic tannins from oak wood chips. Vescalagin and castalagin were the most abundant individual ellagic tannins measured under all extraction conditions. Individual ellagic tannins and ellagic acid increased during the first weeks of extraction, followed by a decrease. Under the extraction conditions examined, temperature was the main factor influencing ellagic tannins and elagic acid evolution. The results suggest that a decrease/degradation of these compounds is less noticeable at low temperatures (12ºC). After 104 extraction days the ellagic tannins content in a model wine solution at 12ºC was higher than the content of ellagic tannins in solutions at 20ºC. On the other hand, the effects of alcoholic content and pH of model wine solutions on the extraction and evolution of the analysed compounds (except for castalagin and vescalagin) seemed to be less important than temperature
Photo Acoustic Study Of Plants Exposed To Varying Light Intensity Growth Conditions: Spectral And Morphological Changes
In this paper we describe results of photo acoustic (PA) measurements carried out on various plants exposed to varying light intensity conditions. Depending on the species and light intensity conditions, the PA absorption spectra show differences in peaks associated with pigments and the cuticle. These differences are related to the spatial distribution of the pigments that differs from plant to plant. We have also performed systematic study of oxygen evolution at different wavelengths. The obtained oxygen spectra are equivalent to the action spectra usually acquired by determining the CO2 uptake and energy storage. The intensities of oxygen spectra exhibit differences depending on distinct morphology of plant. © EDP Sciences.125745748Marquezini, M.V., Cella, N., Mansanares, A.M., Vargas, H., Miranda, L.C.M., (1991) Meas. Sci. Technol., 2, p. 396Barja, P.R., Mansanares, A.M., (1998) Instrum. Sci. Technol., 26, p. 209Barja, P.R., Mansanares, A.M., Da Silva, E.C., Magalhães, A.C.N., Alves, P.L.C.A., (2001) Photosynthetica, 39, p. 489Salisbury, F.B., Ross, C.W., (1992) Plant Physiology, , Wadsworth Publishing Company, CaliforniaClark, J.B., Lister, G.R., (1975) Plant Physiol., 55, p. 401Carpentier, R., Larue, B., Leblanc, R.M., (1983) J. Physique Colloque C6, 44 (10 SUPL), pp. 355-360Veeranjaneyulu, K., Charland, M., Charlebois, D., Leblanc, R.M., (1991) Photosynth. Res., 30, p. 13
Simultaneous Measurement Of Electrical And Thermal Properties: Application To Margarine
An experimental set-up for simultaneous measurement of thermal and dielectric properties of pasty materials, and in particular of margarine is proposed. The objective of the study was to observe simultaneously how the above mentioned properties change when margarine undergoes temperature changes within a temperature range that also encompasses its melting point. The PVDF pyroelectric sensor in combination with the plane plate capacitor was used for simultaneous measurement avoiding thereby problems arising from differences in both, sample's quantity and specific portion taken, the illumination level, heating, etc. As result of temperature variations both, the electrical and thermal properties of margarine were shown very sensitive to the structural changes. The reversibility of the modification process was observed. The results obtained with the set-up for simultaneous measurements were compared to those acquired by the methods capable of measuring each of the two properties separately. © EDP Sciences.125849852Pudney, P.D.A., Hancewicz, T.M., Cunningham, D.G., (2002) Spectrosc-int J, 16, p. 217Van Dalen, G., (2002) J Microsc-oxford, 208 (2), p. 116Benzo, Z., Marcano, E., Gomez, C., (2002) J AOAC Int, 85 (4), p. 967Sacchi, R., Addeo, F., Musso, S.S., (1995) Ital J Food Sci, 7 (1), p. 27Dadarlat, D., Gibkes, J., Bicanic, D., (1996) J Food Eng, 30 (1-2), p. 155De Pereira, J.R., Da Silva, E.C., Mansanares, A.M., Miranda, L.C.M., (2001) Analytical Sci., 17, p. 172Longuemart, S., Quiroz, A.G., Dadarlat, D., Sahraoui, A.H., Kolinsky, C., Buisine, J.M., Da Silva, E.C., Neamtu, C., (2002) Instrum. Sci. Technol., 30 (2), p. 157Dadarlat, D., Bicanic, D., Gibkes, J., (1996) Chem. Phys. Lipids, 82 (1), p. 15Marinelli, M., Mercuri, F., Zammit, U., Pizzoferrato, R., Scudieri, F., Dadarlat, D., (1994) Phys. Rev. B, 49, p. 9523Dadarlat, D., Chirtoc, M., Neamtu, C., Candea, R., Bicanic, D., (1990) Phys. Stat. Sol.(a), 121, pp. K23
Perfil de ácidos grasos y comportamiento reológico de aceite y grasa de semillas de achiote (Bixa orellana), y de cacao blanco (Theobroma grandiflorum) y sus mezclas
Annatto seed oil (ASO) and cupuassu seed fat (CSF) were combined at the ratios: 30:70, 50:50, and 70:30 (% w/w). Their fatty acid profile, nutritional quality, FTIR (Fourier Transform Infrared) spectra, and rheological behavior were evaluated. ASO increased the content of polyunsaturated fatty acids in the blends; whereas CSF conferred higher contents of monounsaturated fatty acids. The blends exhibited low atherogenicity and thrombogenicity indices, suggesting nutritional advantages. The Newtonian fluid behavior and FTIR results suggested that mixing ASO and CSF at different proportions did not affect the functional groups. ASO showed an activation energy value which indicated that this fat viscosity was more sensitive to temperature changes. The Newtonian model proved to be suitable to describe the behavior of samples, according to statistical fit parameters R2, χ2, and RSS. The resulting blends presented improved physicochemical properties and nutritional attributes, indicating their feasibility for the development of new products.Se combinaron aceite de semilla de achiote (ASO) y grasa de semilla de cacao blanco (CSF) en las proporciones: 30:70, 50:50 y 70:30 (% p/p), respectivamente. Se evaluó su perfil de ácidos grasos, calidad nutricional, espectros FTIR (Fourier Transform Infrared) y comportamiento reológico. ASO incrementó el contenido de ácidos grasos poliinsaturados en las mezclas, mientras que CSF confirió mayores contenidos de ácidos grasos monoinsaturados. Las mezclas exhibieron bajos índices de aterogenicidad y trombogenicidad, lo que sugiere ventajas nutricionales. El comportamiento del fluido newtoniano y los resultados de FTIR sugirieron que mezclar ASO y CSF en diferentes proporciones no afectó a los grupos funcionales. ASO mostró un valor de energía de activación que indicó que la viscosidad de esta grasa era más sensible a los cambios de temperatura. El modelo newtoniano demostró ser adecuado para describir el comportamiento de las muestras, según los parámetros de ajuste estadístico R2, χ2 y RSS. Las mezclas resultantes presentaron propiedades fisicoquímicas y atributos nutricionales mejorados, lo que indica su viabilidad para el desarrollo de nuevos productos
Alterações músculo-esqueléticas relacionadas com o envelhecimento: causas e consequências
O aumento da população idosa e a crescente procura de tratamentos mais adequados para
aliviar a dor causada pelos fatores que caracterizam o envelhecimento, particularmente a
instalação da sarcopenia, condição associada ao sedentarismo e em alguns casos a
enfermidades como artrites e artrose, são responsáveis pelo desenvolvimento de dores
articulares que impossibilitam a prática de exercício físico, despoletando outros riscos como
a osteoporose e perda da estabilidade postural que em conjunto aumentam o risco de
quedas, lesões e fraturas associadas (Powers & Howley, 1997). Porém, a sua origem
deverá ser igualmente interpretada muitas vezes como consequência das crescentes
limitações do foro ortopédico.
A inatividade conduz a um desuso do sistema músculo-esquelético e naturalmente a uma
hipo-estimulação do tecido muscular conduzindo à atrofia do mesmo com diminuição da
sua função (Tavares, C. 2003). Um exemplo categórico é o caso da osteoartrose do joelho,
uma patologia articular crónica degenerativa, frequente em adultos e idosos que interfere na
mobilidade e autonomia. A osteoartrose é caracterizada pela presença de dor e limitação
funcional, consequência da formação de osteófitos e/ou alteração na integridade da
cartilagem articular, que conduzem a uma perda gradual da força, diminuição da mobilidade
e instabilidade articular. Frequentemente assistimos nos indivíduos com esta patologia a
uma diminuição gradual nos seus níveis de atividade física, já que a imobilização da
articulação contribui para diminuir o processo inflamatório na mesma, diminuindo também a
dor. No entanto, a imobilização da articulação com artrose vai potenciar: a atrofia, o
encurtamento de músculos e tendões, o surgimento de contracturas, a perda de massa
óssea, o aumento do risco de fratura, a redução da mobilidade articular e a degeneração da
cartilagem (Gordon, N., 1992). Assim, a inatividade física torna-se contraproducente, sendo
a prescrição de exercício físico adequado uma forma de combater o avanço progressivo da
doença. O fortalecimento da musculatura peri articular é fundamental para a obtenção do
equilíbrio da articulação, controlando o impacto do pé sobre o solo durante a marcha,
lubrificando a articulação e reduzindo os movimentos anormais entre as superfícies
articulares o que ajuda a diminuir a degeneração da articulação (Roddy, E., W. Zhang, and
M. Doherty, 2005).
A manutenção do equilíbrio é um aspeto determinante na funcionalidade e autonomia
estando relacionado como o sistema visual, somatosensorial e vestibular, com a força dos
membros inferiores, nomeadamente os grupos musculares flexores e extensores das
articulações do joelho e tibiotársica, que tendem a diminuir com a idade. Além disso, as
alterações degenerativas dos discos intervertebrais, somados à diminuição da flexibilidade
e da força das estruturas musculares e das posturas incorretas frequentes, conduzem a
desalinhamentos nas curvaturas da coluna que por sua vez contribuem para a deterioração
do equilíbrio, não só estático, como também dinâmico, e consequentemente do padrão de
marcha. Neste contexto, a realização de atividade física é fundamental na prevenção de
quedas e de fraturas associadas, tendo sido demonstrado por vários estudos que a
participação em programas de exercício e o treino de tarefas especificamente orientadas
para o sistema sensorial e a manutenção da estabilidade postural reduzem
significativamente o número de quedas quando comparado a grupos de controlo, tanto em
homens como em mulheres (Izquierdo et al., 2005; 2004). Em suma, o treino da força com
intensidade moderada a elevada pode ser efetuado com elevada tolerância por parte de
adultos e idosos, com resultados bastante satisfatórios em termos de adaptação
morfológica e funcional, assim como também em termos de propriedades elétricas e
contrácteis.
Tackling tourism-driven development in World Heritage cities: A comparison between Macao, China and Evora, Portugal
World Heritage cities, all over the world, are a centre of tourist attraction. In many of these cities, tourism is one of the main driving forces of local economies. As a result, these cities come under intense pressure to accommodate tourism-driven developments; summed up with the pressure to fulfil the needs of local communities. How development in World Heritage cities can be tackled is, thus, an important issue for both heritage management and urban development. This paper presents two World Heritage cities – Macao, a former Portuguese colony in China and Évora, the capital of Alentejo region in Portugal - as case studies and discusses and compares the way tourism-driven development is being tackled in these cities. Macao’s economy depends almost entirely on tourism-driven activities. While the World Heritage status has added additional attractiveness to Macao, the main attraction there is gambling. On the other hand, Évora is much less dependent on tourism. Similar to Macao, the World Heritage status has raised the attractiveness of Évora as a tourist destination; however, the university plays also a fundamental role. Consequently, despite the efforts of the local authorities, the city is losing its local community. Even if for different reasons, in both case studies, heritage is often sidelined in the urban development agenda. The case studies identify the raise of cultural-driven tourism and the consequent urban developments and illustrate the role of legislations and regulations and the impact of their variation per heritage protection zones. Moreover, it identifies the resultant urban development scenario that enhance or diminish the heritage values of the cities and, therefore, help retain or cause destruction to the very cultural capital that has brought and can bring many more benefits to these cities of outstanding universal value
Tackling tourism-driven development in World Heritage cities: A comparison between Macao, China and Evora, Portugal
World Heritage cities, all over the world, are a centre of tourist attraction. In many of these cities, tourism is one of the main driving forces of local economies. As a result, these cities come under intense pressure to accommodate tourism-driven developments; summed up with the pressure to fulfil the needs of local communities. How development in World Heritage cities can be tackled is, thus, an important issue for both heritage management and urban development. This paper presents two World Heritage cities – Macao, a former Portuguese colony in China and Évora, the capital of Alentejo region in Portugal - as case studies and discusses and compares the way tourism-driven development is being tackled in these cities. Macao’s economy depends almost entirely on tourism-driven activities. While the World Heritage status has added additional attractiveness to Macao, the main attraction there is gambling. On the other hand, Évora is much less dependent on tourism. Similar to Macao, the World Heritage status has raised the attractiveness of Évora as a tourist destination; however, the university plays also a fundamental role. Consequently, despite the efforts of the local authorities, the city is losing its local community. Even if for different reasons, in both case studies, heritage is often sidelined in the urban development agenda. The case studies identify the raise of cultural-driven tourism and the consequent urban developments and illustrate the role of legislations and regulations and the impact of their variation per heritage protection zones. Moreover, it identifies the resultant urban development scenario that enhance or diminish the heritage values of the cities and, therefore, help retain or cause destruction to the very cultural capital that has brought and can bring many more benefits to these cities of outstanding universal value
Relationship between optimism, disease variables, and health perception and quality of life in individuals with epilepsy.
Epilepsy Behav. 2007 Aug;11(1):33-8. Epub 2007 May 29.
Relationship between optimism, disease variables, and health perception and quality of life in individuals with epilepsy.
Pais-Ribeiro J, da Silva AM, Meneses RF, Falco C.
Faculdade de Psicologia e de Ciências da Educação, Universidade do Porto, Rua Dr. Manuel Pereira da Silva, 4200-392 Porto, Portugal. [email protected]
Abstract
Epilepsy is a relatively frequent chronic condition with an important impact on the health perception and quality of life (QOL) of patients. The aim of the present study was to identify variables related to health status perception and QOL in persons with epilepsy. Participants were 200 persons with epilepsy, 53.5% of whom were males. The mean age was 39.6; 95% had seizures, and 99% were taking antiepileptic medication. The self-report questionnaire administered assessed four types of variables: demographic, disease, epilepsy-specific optimistic attitude, and outcome variables. Results demonstrated that an optimistic orientation is related to better perception of physical and mental health status and better perception of QOL. The variables that best predict positive outcomes are optimistic orientation, perception of cognitive functioning, and perception of seizure control. These results question the importance attributed to seizure characteristics for everyday functioning and everyday life of individuals with epilepsy, and stress the importance of facilitating an epilepsy-specific optimistic orientation.
PMID: 17537679 [PubMed - indexed for MEDLIN
Neuroimmunomodulatory and neuroprotective effects of the flavonoid apigenin in in vitro models of neuroinflammation associated with Alzheimer's disease
Neurodegenerative disorders (ND) are characterized by the progressive and irreversible loss of neurons. Alzheimer’s Disease (AD) is the most incident age-related ND, in which the presence of a chronic inflammatory compound seems to be related to its pathogenesis. Different stimuli in the central nervous system (CNS) can induce activation, proliferation, and changes in phenotype and glial function, which can be modulated by anti-inflammatory agents. Apigenin (4,5,7–trihydroxyflavone) is a flavonoid found in abundance in many fruits and vegetables, that has shown important effects upon controlling the inflammatory response. This study evaluated the neuroprotective and neuroimmunomodulatory potential of apigenin using in vitro models of neuroinflammation associated with AD. Co-cultures of neurons and glial cells were obtained from the cortex of newborn and embryonic Wistar rats. After 26 days in vitro, cultures were exposed to lipopolysaccharide (LPS; 1 μg/ml), or IL-1β (10 ng/ml) for 24 h, or to Aβ oligomers (500 nM) for 4 h, and then treated with apigenin (1 μM) for further 24 h. It was observed that the treatment with apigenin preserved neurons and astrocytes integrity, determined by Rosenfeld’s staining and immunocytochemistry for β-tubulin III and GFAP, respectively. Moreover, it was observed by Fluoro-Jade-B and caspase-3 immunostaining that apigenin was not neurotoxic and has a neuroprotective effect against inflammatory damage. Additionally, apigenin reduced microglial activation, characterized by inhibition of proliferation (BrdU+ cells) and modulation of microglia morphology (Iba-1 + cells), and decreased the expression of the M1 inflammatory marker CD68. Moreover, as determined by RT-qPCR, inflammatory stimuli induced by IL-1β increased the mRNA expression of IL-6, IL-1β, and CCL5, and decreased the mRNA expression of IL-10. Contrary, after treatment with apigenin in inflammatory stimuli (IL-1β or LPS) there was a modulation of the mRNA expression of inflammatory cytokines, and reduced expression of OX42, IL-6 and gp130. Moreover, apigenin alone and after an inflammatory stimulus with IL-1β also induced the increase in the expression of brain-derived neurotrophic factor (BDNF), an effect that may be associated with anti-inflammatory and neuroprotective effects. Together these data demonstrate that apigenin presents neuroprotective and anti-inflammatory effects in vitro and might represent an important neuroimmunomodulatory agent for the treatment of neurodegenerative conditions
Phase-resolved Photoacoustic Spectroscopy And Epr Investigation Of Mno2- And Coo-doped Soda-lime Glasses
A discussion on the use of the phase shifts of the photoacoustic signal of different constituents of a composite sample for resolving their individual spectra is presented. It is experimentally shown that as long as we are interested in a qualitative analysis the method is simple and fast. For a quantitative analysis in which the nonradiative relaxation time and the characteristic diffusion time within the optical-absorption depth are sought, the method presents some limitations. This is demonstrated using MnO2- and CoO-doped soda-lime silica glass samples. © 1989 The American Physical Society.40318801884CAS; Chinese Academy of Sciences; DFG; Chinese Academy of Sciences; NRF; Chinese Academy of Sciences; NSFC; Chinese Academy of Sciences; PSI; Chinese Academy of Sciences; RAS; Chinese Academy of Sciences; RFBR; Chinese Academy of Sciences; RPF; Chinese Academy of Sciences; STFC; Chinese Academy of Science
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