Polytechnic Institute of Braganc a
Polytechnic Institute of Braganc a
Strasser T.,AIT Austrian Institute of Technology |
Andren F.,AIT Austrian Institute of Technology |
Kathan J.,AIT Austrian Institute of Technology |
Cecati C.,University of L'Aquila |
And 12 more authors.
IEEE Transactions on Industrial Electronics | Year: 2015
Renewable energy sources are one key enabler to decrease greenhouse gas emissions and to cope with the anthropogenic climate change. Their intermittent behavior and limited storage capabilities present a new challenge to power system operators to maintain power quality and reliability. Additional technical complexity arises from the large number of small distributed generation units and their allocation within the power system. Market liberalization and changing regulatory framework lead to additional organizational complexity. As a result, the design and operation of the future electric energy system have to be redefined. Sophisticated information and communication architectures, automation concepts, and control approaches are necessary in order to manage the higher complexity of so-called smart grids. This paper provides an overview of the state of the art and recent developments enabling higher intelligence in future smart grids. The integration of renewable sources and storage systems into the power grids is analyzed. Energy management and demand response methods and important automation paradigms and domain standards are also reviewed. © 1982-2012 IEEE.
Glamoclija J.,University of Belgrade |
Ciric A.,University of Belgrade |
Nikolic M.,University of Belgrade |
Fernandes A.,Polytechnic Institute of Braganc a |
And 5 more authors.
Journal of Ethnopharmacology | Year: 2015
Ethnopharmacological relevance: In Russian traditional medicine, an extract from the mushroom Inonotus obliquus (Fr.) Pilát is used as an anti-tumor medicine and diuretic. It has been reported that Inonotus obliquus has therapeutic effects, such as anti-inflammatory, immuno-modulatory and hepatoprotective effects. This study was designed to investigate the chemical composition and biological properties of aqueous and ethanolic extracts of Inonotus obliquus from Finland, Russia, and Thailand. Their antioxidative, antimicrobial, and antiquorum properties were tested as well as the cytotoxicity on various tumor cell lines. Materials and methods: The tested extract was subjected to conventional chemical study to identified organic acids and phenolic compounds. Antioxidative activity was measured by several different assays. Antimicrobial potential of extracts was tested by microdilution method, and antiquorum sensing activity and antibiofilm formation of Inonotus obliquus extracts was tested on Pseudomonas aeruginosa. Cytotoxicity of the extracts was tested on tumor cells (MCF-7, NCI-H460, HeLa and HepG2) and non-tumor liver cells primary cultures. Results: Oxalic acid was found as the main organic acid, with the highest amount in the aqueous extract from Russia. Gallic, protocatechuic and p-hydroxybenzoic acids were detected in all samples. Inonotus obliquus extracts showed high antioxidant and antimicrobial activity. Extracts were tested at subMIC for anti-quorum sensing (AQS) activity in Pseudomonas aeruginosa and all extracts showed definite AQS activity. The assays were done using twitching and swarming of bacterial cultures, and the amount of produced pyocyanin as QS parameters. All the extracts demonstrated cytotoxic effect on four tumor cell lines and not on primary porcine liver cells PLP2. Conclusions: As the Inonotus obliquus presence in Chaga conks is limited, further purification is necessary to draw quantitative conclusions. The presence of AQS activity in medicinal mushrooms suggests a broader anti-infectious disease protection than only immunomodulatory effects. © 2015 Elsevier Ireland Ltd. All rights reserved.
Pinela J.,Polytechnic Institute of Braganc a |
Pinela J.,University of Porto |
Antonio A.L.,Polytechnic Institute of Braganc a |
Antonio A.L.,University of Lisbon |
And 9 more authors.
RSC Advances | Year: 2015
In this study, the effect of different doses of gamma-irradiation (0, 1, 5 and 10 kGy) on colour, antioxidant activity and phenolic compounds of shade- and freeze-dried samples of Tuberaria lignosa were evaluated and compared. The last two parameters were assessed using decoctions and infusions in order to investigate the influence of the preparation method as well. In general, gamma-irradiation has no influence on colour parameter; changes caused by this technology were only identifiable on the lipid peroxidation inhibition capacity of the shade-dried samples and also on a few phenolic compounds. Differences among preparation method were significant for all assayed parameters, with decoctions being preferable over infusions, as indicated by the higher antioxidant activity and levels of phenolic compounds. Overall, the gamma-irradiation treatment (up to 10 kGy) did not significantly affect the analyzed parameters. Nevertheless, other studies are of interest to evaluate the preservation effectiveness of this technology. © The Royal Society of Chemistry 2015.
Reis F.S.,Polytechnic Institute of Braganc a |
Ciric A.,University of Belgrade |
Stojkovic D.,University of Belgrade |
Barros L.,Polytechnic Institute of Braganc a |
And 3 more authors.
Drug Development and Industrial Pharmacy | Year: 2015
The genus Penicillium is well known for its importance in drug and food production. Certain species are produced on an industrial scale for the production of antibiotics (e.g. penicillin) or for insertion in food (e.g. cheese). In the present work, three Penicillium species, part of the natural mycobiota growing on various food products were selected - P. ochrochloron, P. funiculosum and P. verrucosum var. cyclopium. The objective of our study was to value these species from the point of view of production of bioactive metabolites. The species were obtained after inoculation and growth in Czapek and Malt media. Both mycelia and culture media were analyzed to monitor the production of different metabolites by each fungus and their release to the culture medium. The concentrations of sugars, organic acids, phenolic acids and tocopherols were determined. Antioxidant activity of the phenolic extracts was evaluated, as also the antimicrobial activity of phenolic acids, organic acids and tocopherols extracts. Rhamnose, xylose, fructose and trehalose were found in all the mycelia and culture media; the prevailing organic acids were oxalic and fumaric acids, and protocatechuic and p-hydroxybenzoic acids were the most common phenolic acids; g-tocopherol was the most abundant vitamin E isoform. Generally, the phenolic extracts corresponding to the mycelia samples revealed higher antioxidant activity. Concerning the antimicrobial activity there were some fluctuations, however all the studied species revealed activity against the tested strains. Therefore, the in-vitro bioprocesses can be an alternative for the production of bioactive metabolites that can be used by pharmaceutical industry. © 2013 Informa Healthcare USA, Inc.