From cellulosic based liquid crystalline sheared solutions to 1D and 2D soft materials

Liquid crystalline cellulosic-based solutions described by distinctive properties are at the origin of different kinds of multifunctional materials with unique characteristics. These solutions can form chiral nematic phases at rest, with tuneable photonic behavior, and exhibit a complex behavior associated with the onset of a network of director field defects under shear. Techniques, such as Nuclear Magnetic Resonance (NMR), Rheology coupled with NMR (Rheo-NMR), rheology, optical methods, Magnetic Resonance Imaging (MRI), Wide Angle X-rays Scattering (WAXS), were extensively used to enlighten the liquid crystalline characteristics of these cellulosic solutions. Cellulosic films produced by shear casting and fibers by electrospinning, from these liquid crystalline solutions, have regained wider attention due to recognition of their innovative properties associated to their biocompatibility. Electrospun membranes composed by helical and spiral shape fibers allow the achievement of large surface areas, leading to the improvement of the performance of this kind of systems. The moisture response, light modulated, wettability and the capability of orienting protein and cellulose crystals, opened a wide range of new applications to the shear casted films. Characterization by NMR, X-rays, tensile tests, AFM, and optical methods allowed detailed characterization of those soft cellulosic materials. In this work, special attention will be given to recent developments, including, among others, a moisture driven cellulosic motor and electro-optical devices.

Molecular mobility, composition and structure analysis in glycerol plasticised chitosan films

This study was developed with the purpose to investigate the effect of polysaccharide/plasticiser concentration on the microstructure and molecular dynamics of polymeric film systems, using transmission electron microscope imaging (TEM) and nuclear magnetic resonance (NMR) techniques. Experiments were carried out in chitosan/glycerol films prepared with solutions of different composition. The films obtained after drying and equilibration were characterised in terms of composition, thickness and water activity. Results show that glycerol quantities used in film forming solutions were responsible for films composition; while polymer/total plasticiser ratio in the solution determined the thickness (and thus structure) of the films. These results were confirmed by TEM. NMR allowed understanding the films molecular rearrangement. Two different behaviours for the two components analysed, water and glycerol were observed: the first is predominantly moving free in the matrix, while glycerol is mainly bounded to the chitosan chain. (C) 2013 Elsevier Ltd. All rights reserved.

Novos pol��meros conjugados baseados em calixarenos contendo fontes quirais de origem natural: s��ntese, propriedades e aplica����es sensoriais

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Qu��mica e Biol��gica

Aplica����o de ze��litos hier��rquicos a reac����es de acila����o de Friedel-Crafts

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Qu��mica

Calixarenos met��licos catalisadores de reac����es org��nicas industriais sustent��veis

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Qu��mica e Biol��gica

Solubilities of C���Tetraalkylcalix[4]resorcinarenes in SCCO2: experimental measurements, characterization, and correlation

The solubilities of two C-tetraalkylcalix[4]resorcinarenes, namely C-tetramethylcalix[4]resorcinarene and C-tetrapentylcalix[4]resorcinarene, in supercritical carbon dioxide (SCCO2) were measured in a flow-type apparatus at a temperature range from (313.2 to 333.2) K and at pressures from (12.0 to 35.0) MPa. The C-tetraalkylcalix[4]resorcinarenes were synthesized applying our optimized procedure and fully characterized by means of gel permeation chromatography, infrared and nuclear magnetic resonance spectroscopy. The solubilities of the C-tetraalkylcalix[4]resorcinarenes in SCCO2 were determined by analysis of the extracts obtained by HPLC with ultraviolet (UV) detection methodology adapted by our team. Four semiempirical density-based models, and the SoaveRedlichKwong cubic equation of state (SRK CEoS) with classical mixing rules, were applied to correlate the solubility of the calix[4]resorcinarenes in the SC CO2. The physical properties required for the modeling were estimated and reported.

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

Dissertation Presented to obtain the Ph.D. in Biochemistry

Development of cyclodextrin-hydrogel polymeric systems in scCO2 for drug delivery

Thesis for the Degree of Master of Science in Bioorganic Universidade Nova de Lisboa, Faculdade de Ci��ncias e Tecnologia

Utiliza����o da Nanotecnologia para o desenvolvimento sustent��vel na ind��stria agro-alimentar

O crescimento populacional esperado para os pr��ximos anos conduzir�� �� necessidade de aumentar a produ����o agr��cola de modo a satisfazer o aumento da procura. Nos ��ltimos anos tem-se assistido a uma evolu����o tecnol��gica nos sistemas de produ����o que tem permitido aumentar a produtividade agr��cola, por vezes �� custa de elevados consumos de energia e com pr��ticas nem sempre ambientalmente corretas. Os desafios que se colocam atualmente s��o no sentido de melhorar a conserva����o de recursos escassos, como o solo e a ��gua, de aumentar a efici��ncia de uso de fatores de produ����o, de encontrar novas culturas, do desenvolvimento da biotecnologia, da diminui����o dos consumos energ��ticos e de melhorar ainda mais as tecnologias associadas �� produ����o. De maneira a responder aos desafios emergentes da procura por alimentos, da escassez de terrenos agr��colas ar��veis bem como da exist��ncia de pragas de insetos e de ervas daninhas, os pesticidas tem vindo a ser usados com maior frequ��ncia, tendo-se assistido a uma contamina����o dos solos e ��guas subterr��neas, causando deste modo um risco para a sa��de dos seres vivos. Neste sentido, v��rios fabricantes de pesticidas est��o a desenvolver novas formula����es contendo pesticidas encapsulados em nanopart��culas como modo de aumentar a sua solubilidade em ��gua, biodisponibilidade, volatilidade, estabilidade e efic��cia. tendo por objetivo um desenvolvimento sustent��vel. Neste trabalho, procedeu-se ao estudo do encapsulamento do herbicida Oxadiargil (5-terc-butil-3-[2,4-dicloro-5-(2-propiniloxi)fenil]-1,3,4-oxadiazol-2(3H)-ona) com a 2-hidroxipropil-��-ciclodextrina (HP-��-CD). O estudo da forma����o do complexo de inclus��o Oxadiargil - HP-��-CD foi realizado em diferentes meios, ��gua desionizada, tamp��o acetato pH = 3,46 e pH = 5,34 e tamp��o fosfato pH = 7,45, com o objetivo de determinar e comparar a sua constante de estabilidade. Verificou-se, em qualquer dos casos, a ocorr��ncia de uma rela����o linear entre o aumento da solubilidade do Oxadiargil e o aumento da concentra����o de HP-��-CD, com um declive inferior a um, o que indicia a forma����o de um complexo na propor����o estequiom��trica de 1:1. Os resultados obtidos permitiram concluir que o processo de complexa����o Oxadiargil - HP-��-CD n��o �� muito influenciado pela constitui����o e pelo pH do meio. De facto, as constantes de estabilidade obtidas para a ��gua desionizada e solu����es-tamp��o pH = 3,46, pH = 5,34 e pH = 7,45 foram de 919 �� 25, 685 �� 13, 623 �� 17 e 753 �� 9, respetivamente. A solubilidade do complexo obtido nos estudos realizados, em diferentes meios, �� cerca de 23 a 32 vezes superior �� observada para o Oxadiargil livre. De forma a caracterizar o complexo Oxadiargil - HP-��-CD procedeu-se �� sua s��ntese utilizando o m��todo de ���kneading���. O composto obtido foi caracterizado por Resson��ncia Magn��tica Nuclear (RMN) tendo-se confirmado a forma����o de um complexo de inclus��o na propor����o estequiom��trica de 1:1. O complexo obtido �� mais sol��vel e porventura mais est��vel quimicamente. O encapsulamento permite uma redu����o da aplica����o dos pesticidas diminuindo assim os custos e o impacto negativo no ambiente. Com a nanotecnologia �� poss��vel a liberta����o controlada dos pesticidas, aumentando a sua efic��cia e fornecendo os meios necess��rios para um desenvolvimento sustent��vel.

Metabolic flux analysis of neural cell metabolism in primary cultures

Dissertation presented to obtain the Ph.D degree in Biochemistry, Neuroscience

Volumoso Pseudoaneurisma do Ventr��culo Esquerdo ap��s Cirurgia Card��aca

A 75-year old female patient, with previous inferior acute myocardial infarction (AMI) in December 2000, was admitted in April 2001 with angina and heart failure. Transthoracic echocardiography (TTE) was suggestive of a postero-inferior pseudoaneurysm (PA) of the left ventricle (LV), with 61x49 mm. of size and mitral regurgitation. Cardiac catheterization was suspected of a PA of the LV and revealed a three vessels coronary artery disease. On 20th April she was submitted to cardiac surgery with resection of a large LV aneurysm (AN) and triple coronary artery bypass surgery. Afterwards, she was on NYHA class III and subsequent TTE and transesophagic echocardiography (TEE) were suggestive of a 90x60 mm LV posterior PA (confirmed by nuclear magnetic resonance) and severe mitral regurgitation, with good LV systolic function. She underwent a new cardiac surgery on 31st May 2002, with resuturing of the LV postero-inferior wall patch and removal of the PA. The patient is in good condition and on NYHA functional class I-II.

Influence of Hydroxypropyl- �� -Cyclodextrin on the Photostability of Fungicide Pyrimethanil

Pesticides continue to play an important role in pest management. However, the intensive pesticide application has triggered several environment negative effects that cannot be disregarded. In this study, the inclusion complex of pyrimethanil with HP- �� -CD has been prepared and characterized by proton nuclear magnetic resonance spectroscopy. The formation of the pyrimethanil/HP- �� -CD inclusion complex increased the aqueous solubility of this fungicide around five times. To assess the influence of microencapsulation on the environmental photostability of the fungicide, the photochemical degradation of pyrimethanil and pyrimethanil/HP- �� -CD inclusion complex has been investigated in different aqueous media such as ultrapure and river water under simulated solar irradiation. The studies allow concluding that pyrimethanil/HP- �� -CD inclusion complex increases significantly the photostability of the fungicide in aqueous solutions, especially in natural water. Actually, the half-life of pyrimethanil/HP- �� -CD inclusion complex was increased approximately by a factor of four when compared to the free fungicide. The overall results point out that pyrimethanil can be successfully encapsulated by HP- �� -CD, a process that can improve its solubility and photostability properties.

Integrated study by NMR and X-ray Crystallography on the analysis of the molecular interactions in heme-binding proteins

Disserta����o para obten����o do Grau de Doutor em Bioqu��mica, Especialidade Bioqu��mica Estrutural

Structural and functional studies of PpcA: a key protein in the electron transfer pathways of Geobacter sulfurreducens

Disserta����o para obten����o do Grau de Doutor em Bioqu��mica, ramo de Biotecnologia

Molecular determinants of ligand specificity in carbohydrate-binding modules: an NMR and X-ray crystallography integrated study

Disserta����o para obten����o do Grau de Doutor em Bioqu��mica ��� Ramo Bioqu��mica Estrutural