Les enjeux de la construction de la politique d'immigration au Portugal

Comunicação apresentada no Congresso Internacional do IIAS, realizado em Lausanne, Suiça, de 4 a 8 de Julho de 2011.

Otimização da Amostragem e Estudo de Viabilidade da Monitorização de Sondas na ETAR de Rabada

Mestrado em Engenharia Química - Tecnologias de Protecção Ambiental

Generation of high-affinity monoclonal antibodies of IgG class against native β-d-glucans from basidiomycete mushrooms

β-d-glucans from basidiomycete strains are powerful immunomodulatory agents in several clinical conditions. Therefore, their assay, purification and characterization are of great interest to understand their structure-function relationship. Hybridoma cell fusion was used to raise monoclonal antibodies (Mabs) against extracellular β-d-glucans (EBGs) from Pleurotus ostreatus. Two of the hybridoma clones (1E6-1E8-B5 and 3E8-3B4) secreting Mabs against EBGs were selected. This hybridoma cell line secreted Mabs of the IgG class which were then purified by hydroxyapatite chromatography to apparent homogeneity on native and SDS-PAGE. Mabs secreted by 1E6-1E8-B5 clone were found to recognize a common epitope on several β-d-glucans from different basidiomycete strains. This Mab exhibited high affinity constant (KA) for β-d-glucans from several mushroom strains in the range of 3.20 × 109 ± 3.32 × 103-1.51 × 1013 ± 3.58 × 107 L/mol. Moreover, they reacted to some heat-treated β-d-glucans in a different mode when compared with the native forms; these data suggest that this Mab binds to a conformational epitope on the β-d-glucan molecule. The epitope-binding studies of Mabs obtained from 1E6-1E8-B5 and 3E8-3B4 revealed that the Mabs bind to the same epitope on some β-d-glucans and to different epitopes in other antigen molecules. Therefore, these Mabs can be used to assay for β-d-glucan from basidiomycete mushrooms. © 2015 Elsevier Ltd. All rights reserved.

NMR studies of tetrahaem cytochomes from D. desulfuricans and S. frigidimarina

Dissertation Presented to obtain the Ph.D. in Biochemistry

Os Académicos Teatinos no Tempo de D. João V – Construir Saberes enunciando Poder

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em História Moderna e dos Descobrimentos.

Sensor electroquímico seletivo para a Norfloxacina

A Norfloxacina (NFX) é um antibiótico antibacteriano indicado para combater bactérias Gram-negativas e amplamente utilizado para o tratamento de infeções no trato respiratório e urinário. Com a necessidade de realizar estudos clínicos e farmacológicos esenvolveram-se métodos de análise rápida e sensitiva para a determinação da Norfloxacina. Neste trabalho foi desenvolvido um novo sensor eletroquímico sensível e seletivo para a deteção da NFX. O sensor foi construído a partir de modificações efetuadas num elétrodo de carbono vítreo. Inicialmente o elétrodo foi modificado com a deposição de uma suspensão de nanotubos de carbono de paredes múltiplas (MWCNT) de modo a aumentar a sensibilidade de resposta analítica. De seguida um filme polímerico molecularmente impresso (MIP) foi preparado por eletrodeposição, a partir de uma solução contendo pirrol (monómero funcional) e NFX (template). Um elétrodo de controlo não impresso foi também preparado (NIP). Estudouse e caraterizou-se a resposta eletroquímica do sensor para a oxidação da NFX por voltametria de onda quadrada. Foram optimizados diversos parâmetros experimentais, tais como, condições ótimas de polimerização, condições de incubação e condições de extração. O sensor apresenta um comportamento linear entre a intensidade da corrente do pico e o logaritmo da concentração de NFX na gama entre 0,1 e 8μM. Os resultados obtidos apresentam boa precisão, com repetibilidade inferior a 6% e reprodutibilidade inferior a 9%. Foi calculado a partir da curva de calibração um limite de deteção de 0,2 μM O método desenvolvido é seletivo, rápido e de fácil manuseamento. O sensor molecularmente impresso foi aplicado com sucesso na deteção da NFX em amostras de urina real e água.

A luz da grisalha. Arte, liturgia e história no Livro de Horas dito de D. Leonor (Il.165 da BNP)

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em História da Arte Medieval

Um sensor de peróxido de hidrogénio numa bacteria anaeróbia: a PerR de Desulfovobrio vulgaris vulgaris Hildenborough

Dissertação apresentada para obtenção do grau de Mestre em Bioquímica Estrutural e Funcional, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Vitamin D Intake and Cardiometabolic: Risk Factors in Adolescents

Background: A growing body of research suggests that vitamin D might play an important role in overall health. No data exist on vitamin D intake for the Azorean adolescent population. The purpose of this study was to assess vitamin D intake and investigate a possible association between vitamin D intake and cardiometabolic risk factors in Azorean adolescents. Methods: A cross-sectional school-based study was conducted on 496 adolescents (288 girls) aged 15–18 years from the Azorean Islands, Portugal. Anthropometric measurements (waist circumference and height), blood pressure (systolic), and plasma biomarkers [fasting glucose, insulin, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs)] were measured to assess metabolic risk. Homeostasis model assessment (HOMA), TC-to-HDL-C ratio, and waist-to-height ratio were calculated. For each of these variables, a Z-score was computed by age and sex. A metabolic risk score was constructed by summing the Zscores of all individual risk factors. High risk was considered when the individual had ‡ 1 standard deviation(SD) of this score. Vitamin D intake was assessed with a semiquantitative food frequency questionnaire. Participants were classified into quartiles of vitamin D intake. Logistic regression was used to determine odds ratios for high cardiometabolic risk scores after adjusting for total energy intake, pubertal stage, fat mass percentage, and cardiorespiratory fitness. Results: Mean (SD) vitamin D intake was 5.8 (6.5) mg/day, and 9.1% of Azorean adolescents achieved the estimated average requirement of vitamin D (10 mg/day or 400 IU). Logistic regression showed that the odds ratio for a high cardiometabolic risk score was 3.35 [95% confidence interval (CI) 1.28–8.75] for adolescents in the lowest vitamin D intake quartile in comparison with those in the highest vitamin D intake quartile, even after adjustment for confounders. Conclusion: A lower level of vitamin D intake was associated with worse metabolic profile among Azorean adolescents.

Desenvolvimento de um sensor de electroencefalografia localizado

Dissertação apresentada à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para complementar os requerimentos para a obtenção do grau de Mestre em Engenharia Biomédica

Electrospun Polyaniline-Reduced Graphene Oxide Composite Nanofibers Based High Sensitive Ammonia Gas Sensor

Ammonia is an important gas in many power plants and industrial processes so its detection is of extreme importance in environmental monitoring and process control due to its high toxicity. Ammonia’s threshold limit is 25 ppm and the exposure time limit is 8 h, however exposure to 35 ppm is only secure for 10 min. In this work a brief introduction to ammonia aspects are presented, like its physical and chemical properties, the dangers in its manipulation, its ways of production and its sources. The application areas in which ammonia gas detection is important and needed are also referred: environmental gas analysis (e.g. intense farming), automotive-, chemical- and medical industries. In order to monitor ammonia gas in these different areas there are some requirements that must be attended. These requirements determine the choice of sensor and, therefore, several types of sensors with different characteristics were developed, like metal oxides, surface acoustic wave-, catalytic-, and optical sensors, indirect gas analyzers, and conducting polymers. All the sensors types are described, but more attention will be given to polyaniline (PANI), particularly to its characteristics, syntheses, chemical doping processes, deposition methods, transduction modes, and its adhesion to inorganic materials. Besides this, short descriptions of PANI nanostructures, the use of electrospinning in the formation of nanofibers/microfibers, and graphene and its characteristics are included. The created sensor is an instrument that tries to achieve a goal of the medical community in the control of the breath’s ammonia levels being an easy and non-invasive method for diagnostic of kidney malfunction and/or gastric ulcers. For that the device should be capable to detect different levels of ammonia gas concentrations. So, in the present work an ammonia gas sensor was developed using a conductive polymer composite which was immobilized on a carbon transducer surface. The experiments were targeted to ammonia measurements at ppb level. Ammonia gas measurements were carried out in the concentration range from 1 ppb to 500 ppb. A commercial substrate was used; screen-printed carbon electrodes. After adequate surface pre-treatment of the substrate, its electrodes were covered by a nanofibrous polymeric composite. The conducting polyaniline doped with sulfuric acid (H2SO4) was blended with reduced graphene oxide (RGO) obtained by wet chemical synthesis. This composite formed the basis for the formation of nanofibers by electrospinning. Nanofibers will increase the sensitivity of the sensing material. The electrospun PANI-RGO fibers were placed on the substrate and then dried at ambient temperature. Amperometric measurements were performed at different ammonia gas concentrations (1 to 500 ppb). The I-V characteristics were registered and some interfering gases were studied (NO2, ethanol, and acetone). The gas samples were prepared in a custom setup and were diluted with dry nitrogen gas. Electrospun nanofibers of PANI-RGO composite demonstrated an enhancement in NH3 gas detection when comparing with only electrospun PANI nanofibers. Was visible higher range of resistance at concentrations from 1 to 500 ppb. It was also observed that the sensor had stable, reproducible and recoverable properties. Moreover, it had better response and recovery times. The new sensing material of the developed sensor demonstrated to be a good candidate for ammonia gas determination.

Desenvolvimento de um oxímetro de pulso e de um sensor de medição de pressão arterial

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

D. João V e a lisonja

pp. 161-176