New synthetic asymmetric methodologies for the synthesis of bioactive building blocks and potential scale up/out

Preparation of medicinal relevant small molecules from biomass is a field of interest due to 1) structural diversity obtained in biomass modification, 2) being sustainable and an environmentally friendly approach, 3) low cost of starting materials most likely lead to low cost of final product. Amoungst biomass, the furans have been given special attention by the scientific community, namely furfural and 5-hydroxymethylfurfural (HMF). They can be obtained by de dehydration of non-edible carbohydrates and have been described as key building blocks for the future. On the other hand, cyclopentenones (CP) are a class of molecules that has used for medicinal purposes. The transformation of furfural to trans-4,5-diamino-cyclopent-2-enones or other CP derivatives has been reported by several different methodologies being available. However there has been no attempts on taking advantage of this sustainable transformation towards the development of new bioactive molecules. Also, although the transformation of furfural, Meldrum’s acid activated furfural and furyl alcohols to cyclopentenones has been studied, the same transformation using HMF has yet to be succeeded. In this thesis we studied the transformation of furans to CP, taking into consideration sustentability and possible scale up/out, and evaluate their biological activity. We observed that diferent families of CP prepared from furfural have remarkable anticancer and antibacterial activity, while CP prepared from HMF present antimalarial activity. The issue on HMF stability is also address during the course of this thesis, as well as the formation of aminals. The formation of aminals was used as means to protect furfural but was explored as a common protective group of aldehydes, as a way to scavenge genotoxic impurities and as a stimuli-responsive dynamic linker

Sistema de orientação automática para um vibrómetro laser

Mestrado em Engenharia MecânicaThe study of material properties, is in many times done by observation of the material behavior under some vibrations. This vibrations can be measure with a laser vibrometer which has a laser beam that measures using the doppler e ect. This device is available at University of Aveiro, but it is a single point vibrometer, which means that the beam direction is the same as the vibrometer, meaning that, to measure another point it is necessary to move the device. To avoid such issue, it was incorporates, on a system on which a device that de ects the laser beam into desirable locations was added. The process of choosing the points is made using a Kinect which acts as a 3D scanner. To de ect the laser beam of the vibrometer, a galvanometer was used which control is made by an Arduino. The Arduino communicates with MATLAB via Serial communication. Several numerical strategies to de ne automatically a measuring mesh are tested in order to identify their limitations and advantages.O estudo das propriedades dos materiais é muitas vezes realizado a partir da observação do seu comportamento sobre determinados estímulos, tal como vibrações. Estas vibrações podem ser medidas com recurso a um vibrómetro laser sendo que este dispositivo emite um feixe laser e efetua as medições com recurso ao efeito de doppler. Tal dispositivo está disponível na Universidade de Aveiro, sendo este um vibrómetro de ponto único, o que significa que a direção do feixe laser é a direção do vibrómetro, sendo que para obter uma medição noutro ponto é necessário mover o dispositivo. De modo a ultrapassar essa limitação, foi criado um dispositivo onde é incorporado o vibrómetro laser de modo a direcionar o feixe laser para posições pré-definidas. A escolha dos pontos para medição é feita com recurso, a uma câmera Kinect que atua como um scanner 3D. Para deflectir o feixe laser proveniente do vibrómetro foi usado um galvanómetro de espelhos cujo controlo é feito a partir de um Arduino Uno que comunica com o software em MATLAB através de comunicação serie. São analisadas diversas metodologias de definição automática de malha de pontos

Determinação de histamina em peixes e crustáceos comercializados em florianópolis utilizando a eletroforese capilar

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Físicas e Matemáticas. Curso de Química.Aminas Biogênicas (BA) são bases orgânicas de baixa massa molecular sintetizadas durante o processo metabólico em todos os organismos vivos. Estes compostos representam importante grupo de produtos naturais tóxicos e a maioria das intoxicações alimentares causadas por BAs está relacionada com a histamina. Nos peixes, principalmente os pertencentes à família Scombridae e Clupeidae, os níveis de histidina livre (precursora da histamina) nos seus músculos são relativamente altos, o que explica o porquê de serem encontradas concentrações elevadas de histamina sem a formação de indicadores organolépticos de deterioração, como mau odor, perca do brilho das escamas e da transparência dos olhos no cristalino e escurecimento das brânquias. Assim, considerando os potenciais efeitos nocivos da histamina ao desenvolvimento do sistema nervoso e imunológico, uma investigação para desenvolver métodos simples e sensíveis para a sua análise é de grande interesse. Em peixes, a legislação brasileira determina que o conteúdo máximo de histamina, na média das amostras, não deve ser superior a 100 mg/Kg, sendo que nenhuma das amostras pode conter uma concentração superior a 200 mg/kg

Influence of Lorentz-violating terms on a two-level system

The influence of Lorentz- and CPT-violating terms of the extended Standard Model on a semi-classical two-level system is analyzed. It is shown that the Lorentz-violating background (when coupled with the fermion sector in a vector way) is able to induce modifications on the Rabi oscillation pattern, promoting sensitive modulations on the usual oscillations. As for the term involving the coefficient coupled in an axial vector way, it brings about oscillations both on energy states and on the spin states (implied by the background). It is also seen that such backgrounds are able to yield state oscillations even in the absence of the electromagnetic field. The foreseen effects are used to establish upper bounds on the Lorentz-violating coefficients.Comment: 13 pages, 6 figures, revtex style

A gestão do risco cambial um estudo de caso

Dissertação de Mestrado em Contabilidade e FinançasUma vez que a globalização dos negócios é um factor cada vez mais importante, este trabalho reflete a importância da gestão do risco nos mercados internacionais, identificando-os, bem como suas as técnicas de cobertura. Procurou-se fazer uma ligação entre as técnicas de cobertura do risco e as técnicas de pagamento abordadas pela literatura, com as técnicas à disposição das empresas portuguesas, bem como verificar se estas estão preocupadas com esta problemática e se fazem uma eficaz gestão do risco nos mercados internacionais. Foi também realizado um estudo de caso sobre uma empresa portuguesa que aposta fortemente na internacionalização, apresentando um volume de negócios para fora de Portugal acima dos 70%. Verificou-se que esta empresa apresenta algumas preocupações relativas ao risco, mas que não utiliza instrumentos financeiros para o efeito, sendo que o principal motivo é a não existência destes no seu principal marcado – Angola. Apesar da empresa estar bastante sujeita ao risco cambial, é o risco de crédito o seu principal problema, através dos atrasos nos recebimentos. É, portanto, crucial que a empresa expanda o seu negócio para outros mercados internacionais com baixa correlação com os actuais, evidenciando o efeito de diversificação, com o objectivo de diminuir o risco.Since the globalization of business is an increasingly important factor, this work reflects the importance of risk management in international markets, identifying them as well as the techniques of their coverage. We tried to make a connection between the techniques of hedging and payment techniques discussed in literature with the techniques available to the Portuguese companies, as well as verify that they are concerned about this issue and make an effective risk management in international markets. It also conducted a case study of a Portuguese company that invests heavily in internationalization, with a turnover out of Portugal over 70%. It was found that this company has some concerns about the risk, but that does not use financial instruments for this purpose and the main reason is the lack of these in its flagship brand - Angola. Although the company is very subject to currency risk, credit risk is the main problem, through delays in receipts. It is therefore crucial that the company expand its business to other international markets with low correlation with the current, showing the effects of diversification, with the aim of reducing risk

Long-term biosignals visualization and processing

Thesis submitted in the fulfillment of the requirements for the Degree of Master in Biomedical EngineeringLong-term biosignals acquisitions are an important source of information about the patients’state and its evolution. However, long-term biosignals monitoring involves managing extremely large datasets, which makes signal visualization and processing a complex task. To overcome these problems, a new data structure to manage long-term biosignals was developed. Based on this new data structure, dedicated tools for long-term biosignals visualization and processing were implemented. A multilevel visualization tool for any type of biosignals, based on subsampling is presented, focused on four representative signal parameters (mean, maximum, minimum and standard deviation error). The visualization tool enables an overview of the entire signal and a more detailed visualization in specific parts which we want to highlight, allowing an user friendly interaction that leads to an easier signal exploring. The ”map” and ”reduce” concept is also exposed for long-term biosignal processing. A processing tool (ECG peak detection) was adapted for long-term biosignals. In order to test the developed algorithm, long-term biosignals acquisitions (approximately 8 hours each) were carried out. The visualization tool has proven to be faster than the standard methods, allowing a fast navigation over the different visualization levels of biosignals. Regarding the developed processing algorithm, it detected the peaks of long-term ECG signals with fewer time consuming than the nonparalell processing algorithm. The non-specific characteristics of the new data structure, visualization tool and the speed improvement in signal processing introduced by these algorithms makes them powerful tools for long-term biosignals visualization and processing