Últimos itens adicionados do Acervo: Universidade do Porto

A Universidade do Porto (UP) é uma instituição de ensino superior pública portuguesa, fundada no dia 22 de Março de 1911 por decreto do Governo Provisório da República, mas com origens que remontam ao século XVIII.

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Impacto da educação alimentar em crianças do ensino pré-escolar o caso dos jardins de infância do Agrupamento de Escolas de Alcochete

Ribeiro, Alexandra; Moura, Ana Pinto de; Franchini, Bela; Cunha, Luis M.
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Conferência ou Objeto de Conferência
POR

O papel do treinador de futebol profissional no desenvolvimento positivo dos sues atletas: Um estudo exploratório

Gustavo Emanuel Pinto Zabala
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Dissertação
POR

Expression of the myosin light chains 1, 2 and 3 in the muscle of blackspot seabream (Pagellus bogaraveo, Brunnich), during development

Silva, P; Power, DM; Valente, LMP; Silva, N; Monteiro, RAF; Rocha, E
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
ENG
Previous studies on the histochemistry and immunoreactivity of fibres in lateral muscle of blackspot seabream indicated that there is a developmental transition in the composition of myofibnllar proteins, which presumably reflects changes in contractile function as the fish grows We hypothesize that the phenomenon underscores age and spatial differences in the expression of myosin light chains (MLC), not studied yet in this species In this study, we examined selected stages in the post-hatching development of the muscle of blackspot seabream hatching (0 days), mouth opening (5 days), weaning (40 days) and juveniles (70 days) The spatial expression of embryonic MLC 1 (MLC1), 2 (MLC2) and 3 (MLC3) was studied by in situ hybndization Overall, MLC expression patterns were overlapping and restricted to the fast muscle At hatching and mouth opening, all MLC types were highly expressed throughout the musculature in fast muscle The expression levels in fast muscle remained high until weaning when germinal zones appeared on the dorsal and ventral areas The germinal zones were characterized by small-diameter fast fibres with high levels of MLC expression This pattern persisted up to day 70, when the germinal zones disappeared and expression of MLCs was observed only in the smaller cells of the fast muscle mosaic These results support our hypothesis and...

Editorial

Helena Araújo
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
POR

A relação entre qualidade da educação e crescimento económico: Estimações cross-section com base nos resultados do PISA

João Pedro Sequeira Palas de Amorim Santos
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Dissertação
POR

Development of a controlled release formulation based on SLN and NLC for topical clotrimazole delivery

Souto, EB; Wissing, SA; Barbosa, CM; Muller, RH
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
ENG
Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) are colloidal carrier systems providing controlled release profiles for many Substances. Clotrimazole-loaded SLN and NLC were prepared by the hot high pressure homogenization technique in order to evaluate the physical stability of these particles, as well as the entrapment efficiency of this lipophilic drug and its in vitro release profile. The particle size was analyzed by PCS and LD showing that the particles remained in their colloidal state during 3 months of storage at 4, 20 and 40degreesC. For all tested formulations the entrapment efficiency was higher than 50%. The obtained results also demonstrate the use of these lipid nanoparticles as modified release formulations for lipophilic drugs over a period of 10 h.

O impacto da Confiança na Comunicação Publicitária no Capital Marca: O Caso NOS

Eduarda Sofia Ferreira Pinto
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Dissertação
POR

Development and validation of an HPLC method for the quantitation of 1,3-dihydroxy-2-methylxanthone in biodegradable nanoparticles

Maribel Teixeira; Carlos M M Afonso; Madalena M M Pinto; Carlos Mauricio Barbosa
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
ENG
A rapid and simple high-performance liquid chromatographic method for the analysis of 1,3-dihydroxy-2-methylxanthone (DHMXAN) in biodegradable poly(D,L-lactide-co-glycolide) (PLGA) nanosphere and nanocapsule formulations is developed and validated. The method does not require any complex sample extraction procedure. Chromatographic separation is made with a reversed-phase C18 column, using methanol-water (90:10, v/v) containing 1% (v/v) acetic acid as a mobile phase at a flow rate of 1 mL/min. Identification is made by UV detection at 237 nm. The isocratic system operates at ambient temperature and requires 7.5 min of chromatographic time. The developed method is statistically validated according to ICH guidelines and USP 29 for its specificity, linearity, accuracy, and precision. The assay method proposed in this study is specific for DHMXAN in the presence of nanosphere and nanocapsule excipients. Diode-array analyses confirm the purity of DHMXAN peak in stress conditions (> 99.0%). The method is shown to be linear (r ¿ 0.999) over the concentration range of 0.25-3.0 ¿g/mL. Recovery ranges from 99.0% to 102.7% (RSD: 1.49%) and from 98.3% to 101.6% (RSD: 1.07%) for nanospheres and nanocapsules, respectively. Repeatability (intraassay precision) and intermediate precision is acceptable with RSD values ranging from 0.6% to 1.9% and from 0.3% to 2.0%...

Suporte social em crianças e jovens com PHDA e em obesos: análise comparativa

Gonçalves, V.; Gonçalves, D.; Sousa, R.; Almeida, P.; Viana, Victor; Guardiano, M.
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Conferência ou Objeto de Conferência
POR
[resumo]; [abstract]

Associação entre nível educacional e conhecimentos nutricionais de adolescentes

Esteves, Raquel; Moreira, Pedro; Silva, Gustavo; Ferro-Lebres, Vera; Ribeiro, José
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Conferência ou Objeto de Conferência
POR

Development and characterization of PLGA nanospheres and nanocapsules containing xanthone and 3-methoxyxanthone

Teixeira, M; Alonso, MJ; Pinto, MMM; Barbosa, CM
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
ENG
The aim of the present work was to develop and characterize two different nanosystems, nanospheres and nanocapsules, containing either xanthone (XAN) or 3-methoxyxanthone (3-MeOXAN), with the final goal of improving the delivery of these poorly water-soluble compounds. The xanthones-loaded nanospheres (nanomatrix systems) and nanocapsules (nanoreservoir systems), made of poly(DL-lactide-co-glycolide) (PLGA), were prepared by the solvent displacement technique. The following characteristics of nanoparticle formulations were determined: particle size and morphology, zeta potential, incorporation efficiency, thermal behaviour, in vitro release profiles and physical stability at 4 degrees C. The nanospheres had a mean diameter < 170 nm, a narrow size distribution (polydispersity index < 0.1), and a negative surface charge (zeta potential < -36 mV). Their incorporation efficiencies were 33% for XAN and 42% for 3-MeOXAN. The presence of the xanthones did not affect the nanospheres size and zeta potential. DSC studies indicated that XAN and 3-MeOXAN were dispersed at a molecular level within the polymeric nanomatrix. Nanocapsules were also nanometric (mean size < 300 nm) and exhibited a negative charge (zeta potential < -36 mV). Their incorporation efficiency values (> 77%) were higher than those corresponding to nanospheres for both xanthones. The release of 3-MeOXAN from nanocapsules was similar to that observed for the correspondent nanoemulsion...

Hyperplastic and hypertrophic growth of lateral muscle in blackspot seabream Pagellus bogaraveo from hatching to juvenile

Silva, P; Valente, LMP; Olmedo, M; Galante, MH; Monteiro, RAF; Rocha, E
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
ENG
To understand better the growth mechanisms in the economically important fish Pagellus bogaraveo, in terms of muscle fibre hyperplasia v. hypertrophy, the lateral muscle of this fish was studied morphometrically from hatching to juvenile comparing rostral and caudal locations. Fish were sampled at 0, 5, 23, 40, 70, 100, 140 and 180 days. Fibre types were first identified by succinate dehydrogenase (SDH) and immunostaining with a polyclonal antibody against fish slow myosin (4-96). Morphometric variables were then measured in transverse body sections, at both post-opercular and post-anal locations, to estimate the following variables: total muscle area [A (muscle)], total fibre number [N (fibres)], fibre number per unit area of muscle [N(A) (fibres, muscle)] and cross-sectional fibre area [a (fibres)] of the two main muscle fibre types (white and red). Overall, growth throughout the various stages resulted from increases both in the number and in the size of muscle fibres, paralleled by an expansion of the [A (muscle)]. Nonetheless, that increase was not significant between 0-5 days on one hand and 100-140 days, on the other hand. On the contrary, the [N(A) (fibres, muscle)] declined as the body length increased. Analysis of the muscle growth kinetics suggested that...

Associação entre nível educacional e adequação nutricional de adolescentes

Esteves, Raquel; Moreira, Pedro; Silva, Gustavo; Ferro-Lebres, Vera; Ribeiro, José
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Conferência ou Objeto de Conferência
POR

Impacto da restrição materna e atitude restritiva sobre a criança no seu estado ponderal

Aguiar, C.; Guerra, A.; Silva, Diana; Espinheira, C.; Guardiano. M.; Ribeiro, M.; Almeida, P.; Viana, Victor
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Conferência ou Objeto de Conferência
POR
[resumo]; [abstract]

O design e a demência: estimulação de memórias

Maria João da Câmara Sampaio Rodrigues Pedro
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Dissertação
POR

A Validated LC Method for the Quantitation of Cefotaxime in pH-Sensitive Nanoparticles

Rosa Pereira; Tommy Julianto; Peh Kim Ang; Sharon Sheue Nee Ling; Carlos Mauricio Barbosa; Kah Hay Yuen; Abu Bakar Abdul Majeed
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
ENG
A sensitive and rapid routine LC method was validated for measuring cefotaxime incorporated in three different pH-sensitive nanoparticles. The drug was chromatographed on a C18 reversed-phase column; the mobile phase used was 0.05 M aqueous ammonium acetate, acetonitrile and tetrahydrofuran (87:11:2, v/v) adjusted to pH 5.5 with acetic acid. The flow rate was 1 mL min(-1) and cefotaxime was quantified at 254 nm, with a sensitivity range of 0.005 AUFS. The validated method was specific, linear (R (2) a parts per thousand yen 0.999), precise and accurate in a concentration range of 0.2-50.0 mu g mL(-1). The method was rapid, selective and suitable for evaluation of cefotaxime in pH-sensitive Eudragit nanoparticles.

Perturbação alimentar: uma história antiga, um diagnóstico recente

Aguiar, C.; Gonçalves, D.; Sousa, R.; Viana, Victor; Guardiano, M.
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Conferência ou Objeto de Conferência
POR
[resumo]; [abstract]

Liquidity as an Investment Style - New Evidence

Emanuel Moreira de Sousa
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Dissertação
ENG

Breaking the chains of social exclusion?: the influence of affective inequality in education

Elsa Guedes Teixeira; Helena C. Araújo
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Artigo de Revista Científica
POR

Métricas de Avaliação de Performance na Gestão da Supply Chain de Serviços: uma meta-análise

Maria Cecília Almeida Freitas Camões
Fonte: Universidade do Porto Publicador: Universidade do Porto
Tipo: Dissertação
POR