There is a marked trend in pharmaceutical industry towards the replacement of classical organic methods by “green” alternatives that minimize or eliminate the generation of waste and avoid, where ...possible, the use of toxic and/or hazardous reagents and solvents. In this work the kinetically controlled synthesis of cephalexin by soluble and penicillin G acylase immobilized in sol-gel micro‐particles with magnetic properties was performed in aqueous media with PGME and 7‐ADCA as substrates, at different concentrations of substrate, temperature, pH, enzyme to substrate ratio and acyl donor to nucleophile ratio. Excess acyl donor had a strong effect on cephalexin productivity. A PGME/7‐ADCA ratio of 3 was considered optimum. A maximum specific productivity of $5.9\,{\rm mmol}\,{\rm h}^{ - 1} \,{\rm g}_{{\rm biocatalyst}}^{ - 1} $ at 160 mM 7‐ADCA, 480 mM PGME and low enzyme to substrate ratio at 32.5 U mmol⁻¹ 7‐ADCA was obtained with immobilized PGA in full aqueous medium, suggesting that diffusional limitations were minimized when compared with other commercial biocatalysts. A half‐life of 133 h for the immobilized biocatalyst was estimated during cephalexin synthesis in the presence of 100 mM 7‐ADCA and 300 mM PGME, in 50 mM Tris/HCl at pH 7.2 and 14°C. These results compare quite favorably with those previously reported for the kinetically controlled synthesis of cephalexin. Biotechnol. Bioeng. 2010;107: 753-762.
O direito à saúde é um direito fundamental, para o qual se impõe a existência de um sistema de saúde estruturado e regulado. Em Portugal, o Estado tem aumentado a interação com as entidades da ...economia social que prestam cuidados sociais de saúde, com destaque para as IPSS. Com este estudo pretende-se compreender a adequação da regulação prevista legalmente para as IPSS que disponibilizam respostas sociais na área da saúde e identificar a influência da regulação sobre os serviços disponibilizados por estas instituições. O estudo empírico foi desenvolvido através da metodologia qualitativa, envolvendo a análise de conteúdo às entrevistas realizadas a sete IPSS que operam na área da saúde em Portugal. A pesquisa realizada permitiu concluir que não existe uma adequação plena da regulação aplicável às IPSS que disponibilizam respostas sociais na área da saúde. A inadequação é especialmente evidenciada ao nível das comparticipações financeiras, que se revelam insuficientes, e que limitam a captação de recursos humanos, capacidade de atualização tecnológica e expansão da atividade.
The use of processed limestone sludge as a crosslinking agent for films based on Na-alginate and ɩ-carrageenan/Na-alginate blends was studied. Sorbitol was tested as a plasticizer. The produced gel ...formulations included alginate/sorbitol and carrageenan/alginate/sorbitol mixtures, with tested sorbitol concentrations of 0.0, 0.5 and 1.0 wt%. The limestone sludge waste obtained from the processing of quarried limestone was converted into an aqueous solution of Ca
by dissolution with mineral acid. This solution was then diluted in water and used to induce gel crosslinking. The necessity of using sorbitol as a component of the crosslinking solution was also assessed. The resulting films were characterized regarding their dimensional stability, microstructure, chemical structure, mechanical performance and antifungal properties. Alginate/sorbitol films displayed poor dimensional stability and were deemed not viable. Carrageenan/alginate/sorbitol films exhibited higher dimensional stability and smooth and flat surfaces, especially in compositions with 0.5 wt% sorbitol. However, an increasing amount of plasticizer appears to result in severe surface cracking, the development of a segregation phenomenon affecting carrageenan and an overall decrease in films' mechanical resistance. Although further studies regarding film composition-including plasticizer fraction, film optimal thickness and film/mold material interaction-are mandatory, the attained results show the potential of the reported ɩ-carrageenan/alginate/sorbitol films to be used towards the development of viable films derived from algal polysaccharides.
Incorporation of antioxidant agents in edible films and packages often relies in the usage of essential oils and other concentrated hydrophobic liquids, with reliable increases in antimicrobial and ...antioxidant activities of the overall composite, but with less desirable synthetic sources and extraction methods. Hydroethanolic extracts of commercially-available red macroalgae
were evaluated for their antioxidant potential and phenolic content, as part of the selection of algal biomass for the enrichment of thermoplastic film coatings. The extracts were obtained through use of solid-liquid extractions, over which yield, DPPH radical reduction capacity, total phenolic content, and FRAP activity assays were measured. Solid-to-liquid ratio, extraction time, and ethanol percentages were selected as independent variables, and response surface methodology (RSM) was then used to estimate the effect of each extraction condition on the tested bioactivities. These extracts were electrospun into polypropylene films and the antioxidant activity of these coatings was measured. Similar bioactivities were measured for both 100% ethanolic and aqueous extracts, revealing high viability in the application of both for antioxidant coating purposes, though activity losses as a result of the electrospinning process were above 60% in all cases.
Crowdfunding is an increasingly attractive source to fund social projects. However, to our best knowledge, the study of crowdfunding for social purposes has remained largely unexplored in the ...literature. This research envisages a detailed examination of the role of crowdfunding on the early-stage of the social projects at regional level. By comparing the characteristics of the projects available in the Portuguese Social Stock Exchange platform with others that did not use this source of financial support, we envisage to show the critical role of crowdfunding on regional development. The use of inferential techniques (Chi-square test, the Cramer’s V statistic, the Goodman and Kruskal λ and the odds ratio) demonstrates that the use of the Portuguese Social Stock Exchange platform was linked to the geographical location of the social venture as well as its geographical scope. Also, social ventures located on rural regions are more likely to use social crowdfunding platforms than social ventures located in urban areas. Further, the circumstance of having the social ventures acting at a local or regional level seems to be strongly associated with the possibility of using crowdfunding for financing social projects.
Research on social entrepreneurship highlights how important resources are since a lack of them may undermine a social organization's activity and mission. To maintain or increase the amount of ...resources available, the social entrepreneur needs to manage his/her personal network linkages via social media to connect with current stakeholders and seek new ones. This research uses primary data collected from a survey of social organizations to see whether the social entrepreneur’s network reliance on social media increases the amount of resources available for the social organization. The primary data was collected between January and March 2020. The results obtained from 313 social organizations in Portugal show that the social entrepreneur’s network linkages have a direct and an indirect effect. Directly, managing the social entrepreneur’s linkages with stakeholders seems to attract resources for the social organization. The indirect effects occur via social media usage, firstly, by seeking and establishing relationships with new stakeholders, and secondly, by managing the personal linkages with the current network of stakeholders.
The present work aims to provide the basic characterization of sol–gel immobilized inulinase, a biocatalyst configuration yet unexploited, using as model system the hydrolysis of inulin to fructose. ...Porous xerogel particles with dimensions in slight excess of 10 μm were obtained, yielding an immobilization efficiency of roughly 80%. The temperature– and pH–activity profiles displayed a broader bell-shaped pattern as a result of immobilization. In the latter case, a shift of the optimal pH of 0.5 pH units was observed towards a less acidic environment. The kinetic parameters estimated from the typical Michaelis–Menten kinetics suggest that immobilization in sol–gel did not tamper with the native enzyme conformation, but on the other hand, entrapment brought along mass transfer limitations. The sol–gel biocatalyst displayed a promising operational stability, since it was used in more than 20 consecutive 24-hour batch runs without noticeable decay in product yield. The performance of sol–gel biocatalyst particles doped with magnetite roughly matched the performance of simple sol–gel particles in a single batch run. However, the operational stability of the former proved poorer, since activity decay was evident after four consecutive 24-hour batch runs.
The chemical modification of porphyran hydrocolloid is attempted, with the objective of enhancing its antioxidant and antimicrobial activities. Sulfated galactan porphyran is obtained from commercial ...samples of the red algae Porphyra dioica using Soxhlet extraction with water at 100 °C and precipitation with isopropyl alcohol. The extracted porphyran is then treated with modified L-tyrosines in aqueous medium in the presence of NaOH, at ca. 70 °C. The modified tyrosines L1 and L2 are prepared through a Mannich reaction with either thymol or 2,4-di-tert-butylphenol, respectively. While the reaction with 2,4-di-tert-butylphenol yields the expected tyrosine derivative, a mixture of products is obtained with thymol. The resulting polysaccharides are structurally characterized and the respective antioxidant and antimicrobial activities are determined. Porphyran treated with the N-(2-hydroxy-3,5-di-tert-butyl-benzyl)-L-tyrosine derivative, POR-L2, presents a noticeable superior radical scavenging and antioxidant activity compared to native porphyran, POR. Furthermore, it exhibited some antimicrobial activity against S. aureus. The surface morphology of films prepared by casting with native and modified porphyrans is studied by SEM/EDS. Both POR and POR-L2 present potential applicability in the production of films and washable coatings for food packaging with improved protecting characteristics.
Counterfeiting is a worldwide spread phenomenon with serious economic, social and political impacts on the society. This study examines the profile of consumers who admit to purchasing counterfeit ...products in Portugal. Specifically, it investigates whether demographic profile is able to impact the decision factors that drive consumers to purchase counterfeit products. The investigation reveals that a high proportion of consumers have been involved in some way in the purchase of counterfeit products, although consumers distinguish between counterfeit products that can be dangerous for its well-being (medicine) and vanity (clothes and shoes, perfume), and relatively risk-free (auto-parts, machinery) products. The study developed shows that the factors that influence the buying process of counterfeiting products in Portugal can be grouped into intangible (status, brand, design, exclusivity, fashion) and rational (price, perceived quality and personal satisfaction) factors. Finally, the findings suggest that only in one factor (price) and for age and education, the demographic characteristics seems to be important in the moment of buying counterfeit products.
Este estudo versa sobre a função social das cooperativas, função esta refletida no seu regime jurídico, mais especificamente no seu objeto social, a qual não se circunscreve à satisfação das ...necessidades dos seus membros, devendo atender, igualmente, aos interesses da comunidade onde a cooperativa desenvolve a sua atividade, na sua organização e funcionamento democrático e participado, no seu regime económico assente no valor da equidade, quer quanto aos requisitos de admissão dos membros, quer quanto à distribuição de resultados. O estudo utiliza uma metodologia de investigação eminentemente qualitativa, através de análise documental e realização de entrevistas semiestruturadas aos responsáveis pela gestão de cinco cooperativas de distribuição de água situadas nas localidades do sul do concelho de Paredes, em Portugal. A evidência empírica obtida confirma o importante papel social desempenhado pelas cooperativas, sendo evidente a sua função social intracooperativa e extracooperativa. Como evidência empírica desta função social, apresentam-se as cooperativas de distribuição de água que permitem aos seus membros e à comunidade o acesso à água, a preços médios socialmente aceitáveis e cumprindo todas as exigências legais de fiscalização, controlo e qualidade.
Recibido: 09 mayo 2022Aceptado: 28 octubre 2022
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