Percorrer por autor "Oom, Madalena Salema"
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- Evidence for loss and reacquisition of alcoholic fermentation in a fructophilic yeast lineagePublication . Gonçalves, Carla; Wisecaver, Jennifer H.; Kominek, Jacek; Oom, Madalena Salema; Leandro, Maria José; Shen, Xing-Xing; Opulente, Dana A.; Zhou, Xiaofan; Peris, David; Kurtzman, Cletus P.; Hittinger, Chris Todd; Rokas, Antonis; Gonçalves, PaulaFructophily is a rare trait that consists of the preference for fructose over other carbon sources. Here, we show that in a yeast lineage (the Wickerhamiella/Starmerella, W/S clade) comprised of fructophilic species thriving in the high-sugar floral niche, the acquisition of fructophily is concurrent with a wider remodeling of central carbon metabolism. Coupling comparative genomics with biochemical and genetic approaches, we gathered ample evidence for the loss of alcoholic fermentation in an ancestor of the W/S clade and subsequent reinstatement through either horizontal acquisition of homologous bacterial genes or modification of a pre-existing yeast gene. An enzyme required for sucrose assimilation was also acquired from bacteria, suggesting that the genetic novelties identified in the W/S clade may be related to adaptation to the high-sugar environment. This work shows how even central carbon metabolism can be remodeled by a surge of HGT events.
- Influence of intensive training on salivary flow, on salivary pH and on salivary lactate concentration: consequences for oral healthPublication . Reis, Natacha; Oom, Madalena Salema; Vicente, Ana Filipa; Amorim, Armanda; Delgado, João; Godinho, Catarina
- Low friction hydrogel with diclofenac eluting ability for dry eye therapeutic contact lensesPublication . Silva, Diana C.; Oliveira, Margarida; Marto-Costa, Carolina; Teixeira, João; Oom, Madalena Salema; Pinto, Carlos A.; Saraiva, Jorge A.; Marques, Ana Clara; Fitzhenry, Laurence; Serro, Ana PaulaWhen placed in the eye, contact lenses (CLs) disturb the tear fluid and affect the natural tribological behaviour of the eye. The disruption in the contact mechanics between the ocular tissues can increase frictional shear stress and ocular dryness, causing discomfort. Ultimately, continuous CLs wear can trigger inflammation which is particularly critical for people suffering from dry eye. In this work, a double strategy was followed to obtain therapeutic daily disposable CLs for dry eye: a hydroxyethyl methacrylate (HEMA) based hydrogel was coated with two natural polysaccharides, chitosan (CHI) and hyaluronic acid (HA) and posteriorly loaded with an anti-inflammatory drug (diclofenac, DCF). Material sterilisation was carried out by high hydrostatic pressure (HHP) combined with moderate temperature. The friction coefficient (μ) was determined in the presence of different tear biomolecules (cholesterol, lysozyme and albumin) using a nanotribometer. Drug release experiments were performed in static and in hydrodynamic conditions. The material was extensively characterised, regarding surface morphology/topography, optical properties, water content and swelling behaviour, wettability, ionic and oxygen permeability and mechanical properties. It was found that the coating did not impair the physico-chemical properties relevant for the material’s application in CLs. Besides, it also ensured a sustained release of DCF for 24 h in tests performed in hydrodynamic conditions that simulate those found in the eye, increasing significantly the amount of drug released. It reduced friction, improving the lubrication ability of the hydrogel, and presented antibacterial properties against S. aureus, P. aeruginosa and B. Cereus. The coated samples did not reveal any signs of cytotoxicity or potential eye irritation. Overall, the coating of the hydrogel may be useful to produce daily CLs able to alleviate dry eye symptoms and the discomfort of CLs wearers.
- Vitamin C content: fresh homemade vs. commercial orange juicesPublication . Raposo, Carolina Azaredo; Albuquerque, Tânia Gonçalves; Oom, Madalena Salema; Sanches-Silva, Ana; Costa, Helena S.