Atividade antioxidante e antimicrobiana de extratos de plantas de Pterospartum tridentatum (L.) Willk. in vitro e silvestres

Atividade antioxidante e antimicrobiana de extratos de plantas de Pterospartum tridentatum (L.) Willk. in vitro e silvestres.info:eu-repo/semantics/publishedVersio

Natural extracts from Pterospartum tridentatum at different vegetative stages: extraction yiels, phenolic content and antioxidant activity

The aerial parts of Pterospartum tridentatum, a wild growing species in Portugal used in traditional medicine and gastronomy, were harvested at different stages (vegetative phase, flowering phase and beginning of dormancy) in two locations in Portugal (Malcata and Gardunha mountains), and the respective aqueous extracts have been studied. The influence of the seasonal variation in the extraction yield, total phenolic content and antioxidant activity was evaluated. The extraction was carried out in boiling water in consecutive steps. After each step, the aqueous extract was separated and fresh water was added maintaining the same plant material. The procedure was repeated seven times, within an overall time period of 180 minutes. Higher extraction yields were achieved with plant stems collected at the vegetative phases, either from Malcata or Gardunha regions. The total phenolic content of the extracts from Malcata plants ranged from 273 mg to 400 mg gallic acid equivalent/g dry matter, which was quite similar to that determined for extracts from Gardunha (245 to 394 mg gallic acid equivalent/g dry matter). The antioxidant activity was determined by the radical scavenging activity method using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The greatest radical scavenging activity was observed in the flowers extracts, even though all extracts produced presented a good antioxidant activity. Furthermore, the antioxidant activity was not affected by the exposure of the plant material at 100ºC for long periods of time (180 min). The results show that Pterospartum tridentatum has a great potential to be used as a new source of natural antioxidants for the food industry

Identificação de compostos bioativos em plantas silvestres e plantas in vitro de Pterospartum tridentatum (L.) Willk.

Identificação de compostos bioativos em plantas silvestres e plantas in vitro de Pterospartum tridentatum (L.) Willk.info:eu-repo/semantics/publishedVersio

A motivação dos alunos em simulação empresarial: análise de um ano lectivo

Com o objectivo de avaliar a motivação dos alunos e de identificar os aspectos que tendem a explicar a motivação, elaborou-se um inquérito por questionário aos alunos de Projecto- Simulação Empresarial- do curso de Contabilidade no ano lectivo de 2011/2012 da Escola Superior de Tecnologia e Gestão do Instituto Politécnico de Bragança. Os resultados obtidos revelam uma elevada motivação por parte dos alunos ao longo da Unidade Curricular, tendo sido possível identificar um conjunto de aspectos influenciadores de uma motivação mais elevada, nomeadamente a “Importância na formação global de um licenciado em Contabilidade”, a “Consolidação de conhecimentos” e porque “Proporciona o desenvolvimento da capacidade de iniciativa”

Tribological behavior of bioactive multi-material structures targeting orthopedic applications

Acknowledgments This work was supported by Fundação para a Ciência e Tecnologia (FCT), Portugal through the grants SFRH/BD/140191/2018, SFRH/BD/ 128657/2017 and SFRH/BPD/112111/2015, the project PTDC/EMSTEC/ 5422/2014 and also by project NORTE 01-0145_FEDER-000018. Additionally, this work is supported by FCT with the reference project UID/EEA/04436/2019.The following study proposes a multi-material solution in which Ti6Al4V cellular structures produced by Selective Laser Melting are impregnated with bioactive materials (hydroxyapatite or β-tricalcium phosphate) using press and sintering technique. To assess the tribological response of these structures, an alumina plate was used as a counterpart in a flat-on-flat reciprocating sliding test. Ti6Al4V cellular structures impregnated with bioactive materials displayed the highest wear resistance when compared with the unreinforced structures. Among the bioactive structures, Ti6Al4V cellular structures impregnated with βTCP were the ones with higher wear resistance, having the lowest weight loss. Hence, these structures are promising multifunctional solutions for load-bearing applications by gathering suitable mechanical properties (strength and stiffness); bioactive properties and in addition an improved wear performance.info:eu-repo/semantics/publishedVersio

Vegetable proteins and milk puddings

In recent years, interest in animal free foods has increased tremendously due to factors like BSE crisis, rise of nutritionally dependent illnesses, like diabetes type II, cardiovascular and digestive diseases, along with ethic orientations of denying animal intakes of any kind. The use of proteins from leguminous seeds as an alternative to the animal proteins in dairy desserts was studied. Lupin, pea and soya protein isolates were used in combination with k- carrageenan, gellan and xanthan gum, in order to obtain a synergistic effect. Milk puddings were also produced for comparison. Texture studies suggested that mixed protein /polysaccharide systems, with vegetable proteins and k- carrageenan or gellan gum, would be good systems to develop vegetable gelled desserts. Rheological oscillatory measurements were carried out to clarify the kinetics of gelation and characterise the microstructure of the best performing products. Results from time sweep tests showed that formulations with gellan gum present an industrial advantage over formulations with k-carrageenan, since the maturation time for gellan gels is of the order of 5 /10 h compared with 4 /6 days in the case of k-carrageenan. All the mixed gels presented the typical weak gel structure; therefore, it was possible to perform steady-state measurements, which allowed the observation of a shear-thinning behaviour for all gels

Contributos da NCRF 17 para o cumprimento do objetivo das demonstrações financeiras nas empresas do setor? Análise e reflexão a partir das caraterísticas da envolvente

O setor agrícola integra atualmente grandes explorações de âmbito transnacional, ainda que em Portugal, e também no espaço europeu, estas entidades sejam maioritariamente pequenas. O processo de transformação biológica, enquanto elemento diferenciador nestas atividades, pressupõe que a medição dos ativos biológicos se faça a partir dos seus ciclos produtivos. A aplicação do Justo Valor (JV) é apresentada pelo normativo como o caminho preferencial, ainda que sejam já vários os trabalhos que lhe apontam limitações e pouca aderência à realidade portuguesa. Neste sentido, e com base numa metodologia qualitativa, aprofundou-se a discussão sobre as bases de mensuração destes ativos, de modo a que sejam vistas à luz das idiossincrasias do setor e daquelas que são as principais caraterísticas da envolvente. Concluiu-se, ainda que o espírito da norma não levante dúvidas de interpretação, apontando claramente para a aplicação do JV, que a sua aplicação prática não é tão simples e linear.info:eu-repo/semantics/publishedVersio

Microbial and operational response of an anaerobic fixed bed digester to oleic acid overloads

The effect of oleic acid overloads on biomass accumulation and activity in an anaerobic filter was investigated. An anaerobic fixed-bed reactor specially designed to allow the regular withdrawal of accumulated biomass was used for that purpose. Organic and hydraulic shocks were performed during four days, by stepwise increasing the substrate concentration from 4000 to 20 000 mg COD/l or by reducing the hydraulic retention time from 16 to 3.2 h. During the organic shock, operational performance was more affected than in the hydraulic one, which was the result of the higher degree of inhibition detected in the acetoclastic, hydrogenophilic and syntrophic activities. The ratio adhered/total biomass remained between 17 and 32% during the hydraulic shock, and between 13 and 60% during the organic shock, suggesting a more stable biofilm during the hydraulic shock. A long time (900 h) after the hydraulic shock, hydrogenophilic and syntrophic activities recovered to higher values than before the shock, but after the organic shock only acetoclastic activity recovered pre-shock values. Hydraulic shock induced an increase in tolerance to oleic acid toxicity, evidenced by an increase in the toxicity limit (IC50) from 140+/-30 to 215+/-25 mg/l.Fundação de Ciência e Tecnologia

Influence of inoculum activity on the bio-methanization of a kitchen waste under different waste/inoculum ratios

The use of a granular inoculum prevented acidification during the anaerobic batch biodegradation of a kitchen waste for waste/inoculum ratios in the range of 0.5–2.3 g VS/g VS, when the alkalinity/COD ratio was 37mg NaHCO3/g COD. In similar experiments but using a suspended sludge with a significantly lower activity, the methane production rates and the biodegradability were significantly lower and the pH decreased below 5.5 at the waste/inoculum ratio of 2.3 g VS/g VS. When the added alkalinity was decreased to 2mg NaHCO3/g COD, the ratio waste/inoculum was clearly more important than the inoculum activity, since, irrespective of the sludge used, acidification occurred at waste/inoculum ratios higher than 0.5 g VS/g VS. The advantage of using granular sludge was further investigated in order to define reasonable condition of waste/inoculum ratio and added alkalinity that could be applied in practice. For a waste/inoculum ratio of 1.35, there were no significant differences between the results obtained for the biodegradability and maximum methane production rate (MMPR), when the alkalinity decreased from 44 to 22 mg NaHCO3/g COD.Fundação para a Ciência e Tecnologia (FCT) - Project POCTI/1999/CTA/36524

Wild mushroom extracts potentiate the action of standard antibiotics against multi-resistant bacteria

The indiscriminate use of antibiotics and chemotherapeutic agents and the genetic ability of bacteria to transmit and acquire resistance resulted in the development of resistant species. In the last few years, several studies have been conducted in different countries to demonstrate the efficacy of natural products, not only studying their direct antimicrobial activity but also their capacity as resistance-modifying agents. The main objective of the present work was to evaluate the capacity of five wild mushroom extracts to potentiate the action of standard antibiotics, through synergisms that allow a decrease in their therapeutic doses and ultimately contribute to the reduction of resistances.The authors are grateful to Portuguese Foundation for Science and Technology (FCT) and COMPETE/QREN/EU for the financial support through the research project PTDC/AGR-ALI/110062/2009, and to CHTMAD – Hospital Center of Trás-os-Montes e Alto Douro and Siemens for all the supportinfo:eu-repo/semantics/publishedVersio