Production of secondary metabolites in cell suspension cultures of Ocimum sanctum L.

Dissertação de mestrado em Plant Molecular Biology, Biotechnology and Bioentrepreneurship

Composition and structure variation for magnetron sputtered tantalum oxynitride thin films, as function of deposition parameters

Tantalum oxynitride thin films were produced by magnetron sputtering. The films were deposited usinga pure Ta target and a working atmosphere with a constant N2/O2ratio. The choice of this constant ratiolimits the study concerning the influence of each reactive gas, but allows a deeper understanding of theaspects related to the affinity of Ta to the non-metallic elements and it is economically advantageous.This work begins by analysing the data obtained directly from the film deposition stage, followed bythe analysis of the morphology, composition and structure. For a better understanding regarding theinfluence of the deposition parameters, the analyses are presented by using the following criterion: thefilms were divided into two sets, one of them produced with grounded substrate holder and the otherwith a polarization of −50 V. Each one of these sets was produced with different partial pressure of thereactive gases P(N2+ O2). All the films exhibited a O/N ratio higher than the N/O ratio in the depositionchamber atmosphere. In the case of the films produced with grounded substrate holder, a strong increaseof the O content is observed, associated to the strong decrease of the N content, when P(N2+ O2) is higherthan 0.13 Pa. The higher Ta affinity for O strongly influences the structural evolution of the films. Grazingincidence X-ray diffraction showed that the lower partial pressure films were crystalline, while X-rayreflectivity studies found out that the density of the films depended on the deposition conditions: thehigher the gas pressure, the lower the density. Firstly, a dominant -Ta structure is observed, for lowP(N2+ O2); secondly a fcc-Ta(N,O) structure, for intermediate P(N2+ O2); thirdly, the films are amorphousfor the highest partial pressures. The comparison of the characteristics of both sets of produced TaNxOyfilms are explained, with detail, in the text.

The influence of nitrogen and oxygen additions on the thermal characteristics of aluminium-based thin films

The ternary aluminium oxynitride (AlNxOy) system offers the possibility to obtain a wide range of properties by tailoring the ratio between pure Al, AlNx and AlOy and therefore opening a significant number of possible applications. In this work the thermal behaviour of AlNxOy thin films was analysed by modulated infrared radiometry (MIRR), taking as reference the binary AlOy and AlNx systems. MIRR is a non-contact and non-destructive thermal wave measurement technique based on the excitation, propagation and detection of temperature oscillations of very small amplitudes. The intended change of the partial pressure of the reactive gas (N2 and/or O2) influenced the target condition and hence the deposition characteristics which, altogether, affected the composition and microstructure of the films. Based on the MIRR measurements and their qualitative and quantitative interpretation, some correlations between the thermal transport properties of the films and their chemical/physical properties have been found. Furthermore, the potential of such technique applied in this oxynitride system, which present a wide range of different physical responses, is also discussed. The experimental results obtained are consistent with those reported in previous works and show a high potential to fulfil the demands needed for the possible applications of the systems studied. They are clearly indicative of an adequate thermal response if this particular thin film system is aimed to be applied in small sensor devices or in electrodes for biosignal acquisition, such as those for electroencephalography or electromyography as it is the case of the main research area that is being developed in the group.

Degradação fotocatalítica de petróleo e seus derivados através da utilização de nanopartículas de dióxido de titânio puro e misturado com óxido de grafeno reduzido

Dissertação de mestrado integrado em Engenharia de Materiais

Development and characterization of lipid-based nanosystems for controlled release of bioactive compounds

Tese de Doutoramento em Engenharia Química e Biológica.

Aplicação da metodologia TRIZ a um sistema de aproveitamento de águas pluviais de uma unidade hospitalar

Dissertação de mestrado integrado em Engenharia Civil

Development of polymeric nanoparticles containing neuroprotective compounds of Hypericum perforatum

Tese de Doutoramento em Biologia das Plantas - MAP BIOPLANT

Development of multifunctional coatings deposited on polymers based sensors for biomedical applications

Tese de Doutoramento (Programa Doutoral em Engenharia de Materiais)

Factoriality and the pin-reutenauer procedure

We consider implicit signatures over finite semigroups determined by sets of pseudonatural numbers. We prove that, under relatively simple hypotheses on a pseudovariety V of semigroups, the finitely generated free algebra for the largest such signature is closed under taking factors within the free pro-V semigroup on the same set of generators. Furthermore, we show that the natural analogue of the Pin-Reutenauer descriptive procedure for the closure of a rational language in the free group with respect to the profinite topology holds for the pseudovariety of all finite semigroups. As an application, we establish that a pseudovariety enjoys this property if and only if it is full.

Growth of sulfate reducing bacteria on the methanogenic inhibitor BES

The metabolism of methanogenic archaea is inhibited by 2-bromoethanesulfonate (BES). Methane production is blocked because BES is an analog of methyl-coenzyme M and competes with this key molecule in the last step of methanogenesis. For this reason, BES is commonly used in several studies to avoid growth of acetoclastic and hydrogenotrophic methanogens [1]. Despite its effectiveness as methanogenic inhibitor, BES was found to alter microbial communities’ structure, to inhibit the metabolism of non-methanogenic microorganisms and to stimulate homoacetogenic metabolism [2,3]. Even though sulfonates have been reported as electron acceptors for sulfate- and sulfite-reducing bacteria (SRB), only one study described the reduction of BES by complex microbial communities [4]. In this work, a sulfate-reducing bacterium belonging to Desulfovibrio genus (98 % identity at the 16S rRNA gene level with Desulfovibrio aminophilus) was isolated from anaerobic sludge after several successive transfers in anaerobic medium containing BES as sole substrate. Sulfate was not supplemented to the anaerobic growth medium. This microorganism was able to grow under the following conditions: on BES plus H2/CO2 in bicarbonate buffered medium; on BES without H2/CO2 in bicarbonate buffered medium; and on BES in phosphate buffered medium. The main products of BES utilization were sulfide and acetate, the former was produced by the reduction of sulfur from the sulfonate moiety of BES and the latter likely originated from the carbon backbone of the BES molecule. BES was found, in this study, to represent not only an alternative electron acceptor but also to serve as electron donor, and sole carbon and energy source, supporting growth of a Desulfovibrio sp. obtained in pure culture. This is the first study that reports growth of SRB with BES as electron donor and electron acceptor, showing that the methanogenic inhibitor is a substrate for anaerobic growth.

Caracterização de materiais plásticos usados na indústria têxtil e de vestuário por FTIR

Dissertação de mestrado em Técnicas de Caracterização e Análises Químicas

Effects of fermentation residues on the melt processability and thermomechanical degradation of PHBV produced from cheese whey using mixed microbial cultures

"Available online 28 March 2016"

Anti-inflammatory and antinociceptive activities of Bauhinia monandra leaf lectin

A galactose-specific lectin from Bauhinia monandra leaves (BmoLL) have been purified through ammonium sulphate fractionation followed by guar gel affinity chromatography column. This study aimed to evaluate the potential anti-inflammatory and antinociceptive activity of pure BmoLL in mice. Anti-inflammatory activity was evaluated by 1% carrageenan-induced inflammation in mice treated with BmoLL. Acetic acid-induced abdominal writhing and hot plate methods evaluated antinociceptive activity. BmoLL significantly inhibited the carrageenan-induced paw edema by 47% (30 mg/kg) and 60.5% (60 mg/kg); acetylsalicylic acid (ASA, 100 mg/kg) showed inhibition of 70.5%, in comparison to controls. Leukocyte migration, an immune response to the inflammation process, was significantly reduced in presence of BmoLL; in mice treated with \ASA\ the decrease in leukocyte migration was similar to 15 mg/kg of the lectin. BmoLL at doses of 15, 30 and 60 mg/kg significantly reduced the number of animal contortions by 43.1, 50.1 and 71.3%, respectively.BmoLL leukocyte migration was significantly reduced; in mice treated with \ASA\ the decrease in leukocyte migration was similar to 15 mg/kg of the lectin. BmoLL at doses of 15, 30 and 60 mg/kg significantly reduced the number of animal contortions by 43.1, 50.1 and 71.3%, respectively. The lectin (30 and 60 mg/kg) showed a significant effect in the hot plate assay. BmoLL anti-inflammatory and antinociceptive effects were dose-dependent. The search for new and natural compounds, with minimal side effects, to control pain and inflammation, is constantly increasing. BmoLL has great potential as a natural anti-inflamatory product that can be explored for pharmacological purposes.

Laccase immobilization on bacterial nanocellulose membranes: antimicrobial, kinetic and stability properties

This work studied the physical immobilization of a commercial laccase on bacterial nanocellulose (BNC) aiming to identify the laccase antibacterial properties suitable for wound dressings. Physico-chemical analysis demonstrates that the BNC structure is manly formed by pure crystalline I cellulose. The pH optimum and activation energy of free laccase depends on the substrate employed corresponding to pH 6, 7, 3 and 57, 22, 48 kJ mol1 for 2,6-dimethylphenol (DMP), catechol and 2,2 -azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. The Michaelis-Menten constant (Km) value for the immobilized laccase (0.77 mM) was found to be almost double of that of the free enzyme (0.42 mM). However, the specific activities of immobilized and free laccase are similar suggesting that the cage-like structure of BNC allows entrapped laccase to maintain some flexibility and favour substrate accessibility. The results clearly show the antimicrobial effect of laccase in Gram-positive (92%) and Gram-negative (26%) bacteria and cytotoxicity acceptable for wound dressing applications.

A multi–physics approach applied to masonry structures with non–hydraulic lime mortars

Tese de Doutoramento em Engenharia Civil (área de especialização em Engenharia de Estruturas).