Browsing by Issue Date, starting with "2021"
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- Novel active food packaging films based on whey protein incorporated with seaweed extract: development, characterization, and application in fresh poultry meatPublication . Andrade, Mariana A.; Barbosa, Cássia H.; Souza, Victor G. L.; Coelhoso, Isabel M.; Reboleira, João; Bernardino, Susana; Ganhão, Rui; Mendes, Susana; Fernando, Ana Luisa; Vilarinho, Fernanda; Silva, Ana Sanches; Ramos, FernandoAlgae and seaweeds are used in cookery since the beginnings of human civilization, particularly in several Asian cultures. Phenolic compounds are secondary metabolites produced by aquatic and terrestrial plants for their natural defense against external stimuli, which possess powerful antimicrobial and antioxidant properties that can be very important for the food industry. The main objective of this study was to develop a whey protein concentrate active coating, incorporated with a Fucus vesiculosus extract in order to delay the lipid oxidation of chicken breasts. Ten hydroethanolic extracts from F. vesiculosus were obtained and their antioxidant capacity was evaluated through two antioxidant activity assays: the DPPH radical scavenging activity and -carotene leaching assay. The total content in phenolics compounds was also determined by Folin-Ciocalteu method. The chosen extract was the one obtained from the freeze-dried F. vesiculosus using 75% (v/v) ethanol as extraction solvent. The extract was successfully incorporated into a whey protein film and successfully strengthened the thickness, tensile strength, and elastic modulus. The active film also was able to inhibit the chicken breasts lipid oxidation for 25 days of storage.
- New applications for Gelidium corneum: Antimicrobial and antioxidant activity within a biorefinery conceptPublication . Mouga, Teresa; Cavaco, Mário; Duarte, Adriana; Correia, Ana Patrícia; Freitas, Marta V.; Bernardino, Susana; Afonso, CléliaThere are more than four hundred endogenous seaweeds that occur in Portugal, and red seaweeds (Rhodophyta) are the most abundant. Among these, Gelidium corneum, common in the Atlantic coast of Portugal, is currently being collected in the wild, in S. Martinho do Porto, exclusively for the extraction of agar. During the summer season this species is harvested from the bottom of the ocean, dried and sold, representing an important economic local activity. Yet, besides agar, this species is important for its bioactivities, namely for its antioxidant and antimicrobial capacities, thus most of the biomass is currently being disregarded as an important marine resource. Therefore, to further research the potential of G. corneum as a source of bioactive compounds, the biomass was seasonally harvested and characterized (protein, ash, moisture), and different extract were made (aqueous and ethanolic). These extracts were analyzed for the antioxidant potential (DDPH, ABTS, TPC and FRAP), and for antimicrobial capacity (against Escherichia coli, Bacillus subtilis, Candida albicans, Saccharomyces cerevisiae and Staphylococcus epidermidis). Preliminary results show that there are seasonal variations in the chemical composition of the biomass. Extracts tested also show interesting free radical scavenging capacity and antimicrobial activity against some of the strains tested. The attained results demonstrate that the biorefinery concept should be implemented to the agar industry, valuing the seaweeds’ biomass so to allow its use in other industries, such as textiles or cosmetics.
- Leitores chineses contemporâneos da portuguesa literatura para a infânciaPublication . Nobre, CristinaComo é que os estudantes chineses da licenciatura de Tradução e Interpretação Português-Chinês / Chinês-Português compreendem e interpretam textos de uma língua e cultura estrangeiras, destinados a crianças portuguesas e alcançando públicos tão diferentes (Barreto 2002; Blockeel 2001)? A comparação e o equilíbrio de textos escritos e visuais (Hunt 2004; Kress & van Leewen 2006) foram os meios que ajudaram os estudantes a ultrapassar a menor proficiência numa língua estrangeira. A partir das seleções dos estudantes, que trabalharam em equipa, cada livro (história e ilustração) foi submetido a interpretações multimodais e discutido como um objeto significante. A gramática visual foi o principal instrumento para chegar a conclusões. As ilustrações foram o recurso fundamental que permitiu aos estudantes comparar e moverem-se gradualmente duma escala oriental de valores para uma ocidental, incluindo-se em ambas. A multimodalidade revelou-se como o instrumento nuclear para os estudantes compreenderem as similitudes entre dois mundos semióticos diferentes e alcançarem a literacia dos livros portugueses para crianças.
- Descodificar sinais de sensores de oxigénio para diagnosticar...diabetesPublication . Guarino, Maria Pedro
- The effect of light attractor color in pelagic longline fisheriesPublication . Afonso, André S.; Mourato, Bruno; Hazin, Humberto; Hazin, Fábio H.V.Improving the selectivity of the fishing gear is one of the most promising methods to mitigate deleterious impacts of longline fisheries upon bycatch species. Light lures have recently become widespread in epipelagic longline fisheries since they increase the catch rates of valuable target species such as swordfish and tunas. Yet, little is known about their effect upon the incidence of bycatch. Here, we compared the catchability of target and bycatch species in a pelagic longline fishery targeting swordfish and tunas equipped with light attractors with three different colors to ascertain if any of the light attractor colors would enhance the selectivity of the fishing gear. A total of 3488 individuals were caught across 57 fishing sets. The proportion of target species to bycatch species was high (58–65 %) in each color treatment. Overall, green attractors (peak wavelength at 525 nm) exhibited the highest catch rates of target species, but they were also responsible for the highest incidence of bycatch, rendering 73 % and 82 % of the blue shark and sea turtle catch, respectively. Blue (peak wavelength at 465 nm) and white attractors caught significantly less individuals of both target and bycatch species. Further, significant interactions between light attractor color and the intensity of lunar illumination were observed for most species analyzed. Differences in the catchability of bycatch such as blue sharks and white marlins across attractor color treatments were more conspicuous at high lunar illumination levels (i.e. full moon periods), when white attractors rendered the lowest catch of these taxa. In contrast, the catchability of target species such as swordfish, yellowfin tuna and albacore showed greater differences between treatments at low illumination levels (i.e. new moon periods). The observed differences in the performance of the three light attractor colors across the lunar cycle might provide an opportunity to mitigate bycatch incidence in longline fisheries. Yet, further research is required to fully understand the combined effects of light lures and lunar illumination on the behavioral responses of pelagic species.
- Wall Drop Punt Kick & Catch: Contributions towards the creation of a new gross manipulative coordination testPublication . Mendes, Diogo; Monteiro, Diogo; Antunes, Raul; Rebelo-Goncalves, Ricardo; Coelho, Luís; Salvador, Rogério; Amaro, Nuno; Matos, Rui
- Cytotoxic mechanism of sphaerodactylomelol, an uncommon bromoditerpene isolated from sphaerococcus coronopifoliusPublication . Alves, Celso; Silva, Joana; Pinteus, Susete; Alonso, Eva; Alvarino, Rebeca; Duarte, Adriana; Marmitt, Diorge; Geottert, Márcia Inês; Gaspar, Helena; Alfonso, Amparo; Alpoim, Maria C.; Botana, Luis M; Pedrosa, RuiMarine natural products have exhibited uncommon chemical structures with relevant antitumor properties highlighting their potential to inspire the development of new anticancer agents. The goal of this work was to study the antitumor activities of the brominated diterpene sphaerodactylomelol, a rare example of the dactylomelane family. Cytotoxicity (10–100 M; 24 h) was evaluated on tumor cells (A549, CACO-2, HCT-15, MCF-7, NCI-H226, PC-3, SH-SY5Y, SK-ML-28) and the effects estimated by MTT assay. Hydrogen peroxide (H2O2) levels and apoptosis biomarkers (membrane translocation of phosphatidylserine, depolarization of mitochondrial membrane potential, Caspase-9 activity, and DNA condensation and/or fragmentation) were studied in the breast adenocarcinoma cellular model (MCF-7) and its genotoxicity on mouse fibroblasts (L929). Sphaerodactylomelol displayed an IC50 range between 33.04 and 89.41 M without selective activity for a specific tumor tissue. The cells’ viability decrease was accompanied by an increase on H2O2 production, a depolarization of mitochondrial membrane potential and an increase of Caspase-9 activity and DNA fragmentation. However, the DNA damage studies in L929 non-malignant cell line suggested that this compound is not genotoxic for normal fibroblasts. Overall, the results suggest that the cytotoxicity of sphaerodactylomelol seems to be mediated by an increase of H2O2 levels and downstream apoptosis.
- Caring for patients with end‐stage renal disease during COVID‐19 lockdown: What (additional) challenges to family caregivers?Publication . Sousa, Helena; Frontini, Roberta; Ribeiro, Oscar; Paúl, Constança; Costa, Elisio; Amado, Leonilde; Miranda, Vasco; Ribeiro, Fernando; Figueiredo, DanielaCaring for a patient with end‐stage renal disease undergoing in‐centre haemodialysis can be a stressful experience, likely to involve significant burden. Within the context of the new coronavirus pandemic, these patients are highly vulnerable to infection by COVID‐19, which might increase the care demands and burden of family caregivers.
- As perceções sobre desenvolvimento sustentável dos estudantes de ensino superior em PortugalPublication . Aleixo, Ana Marta; Leal, Susana; Azeiteiro, Ulisses