Percorrer por autor "Ribeiro, Ana Rita"
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- Enantiomeric fraction evaluation of pharmaceuticals in an aerobic granular sludge sequencing batch reactorPublication . Amorim, Catarina L.; Moreira, Irina S.; Ribeiro, Ana Rita; Santos, Lúcia H. M. L. M.; Delerue-Matos, Cristina; Tiritan, Maria Elizabeth; Castro, Paula M. L.
- Enantiomeric fraction evaluation of pharmaceuticals in environmental matrices by liquid chromatography-tandem mass spectrometryPublication . Ribeiro, Ana Rita; Santos, Lúcia H. M. L. M.; Maia, Alexandra S.; Delerue-Matos, Cristina; Castro, Paula M. L.; Tiritan, Maria ElizabethThe interest for environmental fate assessment of chiral pharmaceuticals is increasing and enantioselective analytical methods are mandatory. This study presents an enantioselective analytical method for the quantification of seven pairs of enantiomers of pharmaceuticals and a pair of a metabolite. The selected chiral pharmaceuticals belong to three different therapeutic classes, namely selective serotonin reuptake inhibitors (venlafaxine, fluoxetine and its metabolite norfluoxetine), beta-blockers (alprenolol, bisoprolol, metoprolol, propranolol) and a beta2-adrenergic agonist (salbutamol). The analytical method was based on solid phase extraction followed by liquid chromatography tandem mass spectrometry with a triple quadrupole analyser. Briefly, Oasis® MCX cartridges were used to preconcentrate 250 mL of water samples and the reconstituted extracts were analysed with a Chirobiotic™ V under reversed mode. The effluent of a laboratory-scale aerobic granular sludge sequencing batch reactor (AGS-SBR) was used to validate the method. Linearity (r2 > 0.99), selectivity and sensitivity were achieved in the range of 20–400 ng L−1 for all enantiomers, except for norfluoxetine enantiomers which range covered 30–400 ng L−1. The method detection limits were between 0.65 and 11.5 ng L−1 and the method quantification limits were between 1.98 and 19.7 ng L−1. The identity of all enantiomers was confirmed using two MS/MS transitions and its ion ratios, according to European Commission Decision 2002/657/EC. This method was successfully applied to evaluate effluents of wastewater treatment plants (WWTP) in Portugal. Venlafaxine and fluoxetine were quantified as non-racemic mixtures (enantiomeric fraction ≠ 0.5). The enantioselective validated method was able to monitor chiral pharmaceuticals in WWTP effluents and has potential to assess the enantioselective biodegradation in bioreactors. Further application in environmental matrices as surface and estuarine waters can be exploited.
- Liderança, equipas, rendimento e comprometimento organizacional: estudo sobre método SCRUMPublication . Ribeiro, Ana Rita; Gomes, António Rui Silva; Morais, Catarina; Sousa, Jacinta; Fontes, LilianaEste estudo analisou a relação entre os estilos de liderança e três dimensões da atividade profissional (trabalho em equipa, rendimento profissional e comprometimento organizacional), numa empresa multinacional que utiliza o método Scrum. Mais concretamente: (a) comparou-se a perceção dos membros de equipa acerca da liderança de dois responsáveis de equipa; (b) comparou-se a perceção dos membros de equipa com a perceção dos dois responsáveis de equipa, sobre a sua própria liderança; e (c) analisou-se o valor preditivo dos estilos de liderança nas dimensões de atividade profissional. Participaram no estudo 166 profissionais. Os resultados demonstraram: (a) responsáveis de equipa foram avaliados de forma semelhante pelos membros da equipa, embora um dos responsáveis seja avaliado como assumindo mais comportamentos transformacionais; (b) responsáveis de equipa autoavaliaram a sua liderança de forma mais positiva que os membros da equipa; e (c) dimensões de feedback positivo e gestão ativa explicaram as dimensões da atividade profissional.
- Occurrence of chiral bioactive compounds in the aquatic environment: a reviewPublication . Ribeiro, Cláudia; Ribeiro, Ana Rita; Maia, Alexandra S.; Tiritan, Maria ElizabethIn recent decades, the presence of micropollutants in the environment has been extensively studied due to their high frequency of occurrence, persistence and possible adverse effects to exposed organisms. Concerning chiral micropollutants in the environment, enantiomers are frequently ignored and enantiomeric composition often neglected. However, enantioselective toxicity is well recognized, highlighting the need to include enantioselectivity in environmental risk assessment. Additionally, the information about enantiomeric fraction (EF) is crucial since it gives insights about: (i) environmental fate (i.e., occurrence, distribution, removal processes and (bio)degradation); (ii) illicit discharges; (iii) consumption pattern (e.g., illicit drugs, pharmaceuticals used as recreational drugs, illicit use of pesticides); and (iv) enantioselective toxicological effects. Thus, the purpose of this paper is to provide a comprehensive review about the enantioselective occurrence of chiral bioactive compounds in aquatic environmental matrices. These include pharmaceuticals, illicit drugs, pesticides, polychlorinated biphenyls (PCBs) and polycyclic musks (PCMs). Most frequently analytical methods used for separation of enantiomers were liquid chromatography and gas chromatography methodologies using both indirect (enantiomerically pure derivatizing reagents) and direct methods (chiral stationary phases). The occurrence of these chiral micropollutants in the environment is reviewed and future challenges are outlined.
- Protein hydrolysates from salmon heads and cape hake by-products: comparing enzymatic method with subcritical water extraction on bioactivity propertiesPublication . Pires, Carla; Leitão, Matilde; Sapatinha, Maria; Gonçalves, Amparo; Oliveira, Helena; Nunes, Maria Leonor; Teixeira, Bárbara; Mendes, Rogério; Camacho, Carolina; Machado, Manuela; Pintado, Manuela; Ribeiro, Ana Rita; Vieira, Elsa F.; Delerue-Matos, Cristina; Lourenço, Helena Maria; Marques, AntónioFish by-products can be converted into high-value-added products like fish protein hydrolysates (FPHs), which have high nutritional value and are rich in bioactive peptides with health benefits. This study aims to characterise FPHs derived from salmon heads (HPSs) and Cape hake trimmings (HPHs) using Alcalase for enzymatic hydrolysis and Subcritical Water Hydrolysis (SWH) as an alternative method. All hydrolysates demonstrated high protein content (70.4–88.7%), with the degree of hydrolysis (DH) ranging from 10.7 to 36.4%. The peptide profile of FPHs indicated the breakdown of proteins into small peptides. HPSs showed higher levels of glycine and proline, while HPHs had higher concentrations of glutamic acid, leucine, threonine, and phenylalanine. Similar elemental profiles were observed in both HPHs and HPSs, and the levels of Cd, Pb, and Hg were well below the legislated limits. Hydrolysates do not have a negative effect on cell metabolism and contribute to cell growth. HPSs and HPHs exhibited high 2,2′–azino-bis(3 ethylbenzthiazoline-6)-sulfonic acid (ABTS) radical scavenging activity, Cu2+ and Fe2+ chelating activities, and angiotensin-converting enzyme (ACE) inhibitory activity, with HPHs generally displaying higher activities. The α-amylase inhibition of both FPHs was relatively low. These results indicate that HPHs are a promising natural source of nutritional compounds and bioactive peptides, making them potential candidates for use as an ingredient in new food products or nutraceuticals. SWH at 250 °C is a viable alternative to enzymatic methods for producing FPHs from salmon heads with high antioxidant and chelating properties.