Development of novel active pharmaceutical ionic liquids and salts based on antibiotics and anti-fungal drugs

Ionic Liquids (ILs) are class of compounds, which have become popular since the mid-1990s. Despite the fact that ILs are defined by one physical property (melting point), many of the potential applications are now related to their biological properties. The use of a drug as a liquid can avoid some problems related to polymorphism which can influence a drug´s solubility and thus its dosages. Also, the arrangement of the anion or cation with a specific drug might be relevant in order to: a) change the correspondent biopharmaceutical drug classification system; b) for the drug formulation process and c) the change the Active Pharmaceutical Ingredients’ (APIs). The main goal of this Thesis is the synthesis and study of physicochemical and biological properties of ILs as APIs from beta-lactam antibiotics (ampicillin, penicillin G and amoxicillin) and from the anti-fungal Amphotericin B. All the APIs used here were neutralized in a buffer appropriate hydroxide cations. The cation hydroxide was obtained on Amberlite resin (in the OH form) in order to exchange halides. The biological studies of these new compounds were made using techniques like the micro dilution and colorimetric methods. Overall a total of 19 new ILs were synthesised (6 ILs based on ampicillin, 4 ILs, based on amoxicillin, 6 ILs based on penicillin G and 4 ILs based on amphotericin B) and characterized by spectroscopic and analytical methods in order to confirm their structure and purity. The study of the biological properties of the synthesised ILs showed that some have antimicrobial activity against bacteria and yeast cells, even in resistant bacteria. Also this work allowed to show that ILs based on ampicillin could be used as anti-tumour agents. This proves that with a careful selection of the organic cation, it is possible to provoke important physico-chemical and biological alteration in the properties of ILs-APIs with great impact, having in mind their applications.

UAV - based imagery processing using structure from motion and remote sensing technology

With the recent advances in technology and miniaturization of devices such as GPS or IMU, Unmanned Aerial Vehicles became a feasible platform for a Remote Sensing applications. The use of UAVs compared to the conventional aerial platforms provides a set of advantages such as higher spatial resolution of the derived products. UAV - based imagery obtained by a user grade cameras introduces a set of problems which have to be solved, e. g. rotational or angular differences or unknown or insufficiently precise IO and EO camera parameters. In this work, UAV - based imagery of RGB and CIR type was processed using two different workflows based on PhotoScan and VisualSfM software solutions resulting in the DSM and orthophoto products. Feature detection and matching parameters influence on the result quality as well as a processing time was examined and the optimal parameter setup was presented. Products of the both workflows were compared in terms of a quality and a spatial accuracy. Both workflows were compared by presenting the processing times and quality of the results. Finally, the obtained products were used in order to demonstrate vegetation classification. Contribution of the IHS transformations was examined with respect to the classification accuracy.

How do current term structure model behave beyond the last liquid point?: A comparison of the DNS and Smith-Wilson methods

A Work Project, presented as part of the requirements for the Award of a Master’s Double Degree in Finance from Maastricht University and NOVA – School of Business and Economics

Aptamers binding to Bradykinin

Bradykinin is a peptide of the kinin group, involved in a number of receptor-mediated physiological actions, including inflammation and vasodilation, as well as neuromodulation, neuroprotection and promotion of neurogenesis. Bradykinin is the main ligand of the B2 receptor- the main kinin receptor- which is involved in the cardiac and renal protective effects of kinins in diseases. Antibodies have been considered for a long time as promising therapeutic agents in various fields, especially cancer-related ones. Aptamers, on the other hand, have proven to be an excellent alterative, since they have similar properties to those of monoclonal antibodies, such a high-specificity of recognition and high-affinity binding. Plus, they are developed using in vitro selection procedures and can be reproduced by enzymatic reactions. SELEX is a powerful tool for the development of both DNA and RNA aptamers. The main goal of this project was to design a method to select aptamers against bradykinin using capillary electrophoresis alongside the SELEX technique. The selection was done by comparing the aptamers’ (ssDNA-target complex) electrophoretic mobility with that of the ssDNA and the target, which allowed us to define an appropriate collection window that took into consideration the analytes’ detection time, thus enabling the collection of the desired oligonucleotides. After two selection rounds, the collected pool was sequenced, the affinity was measured and the aptamers’ secondary structure was predicted. We concluded that with only two selection cycles, the original DNA library’s bulk affinity grew around 0.4%. The structural characterization of the aptamers, performed with the aid of the Mfold software, revealed that there are many repetitive motifs amongst them, indicating that the selection process was successful. We have obtained 16 sequences of candidate aptamers as bradykinin ligands of similar sequences and secondary structures whose biological activity should be analyzed after synthesis; mainly in regard to their role as bradykinin inhibitors.

Design and characterization of novel biopolymeric structure using biocompatible ionic liquids

The main objective of this thesis was the development of polymeric structures from the dissolution of FucoPol, a bacterial exopolysaccharide (EPS), in a biocompatible ionic liquid, choline acetate. The FucoPol was produced by the bacteria Enterobacter A47 using glycerol as carbon source at controlled temperature and pH (30ºC and 7, respectively). At the end of 3 days it was produced 7 g/L of FucoPol. The net yield of Fucopol in glycerol (YP/S) was 0.22 g/g and the maximum productivity 2.37 g/L.d This polymer was characterized about its composition in sugars and acyl groups (by High-Performance Liquid Chromatography - HPLC), containing fucose (35 % mol), galactose (21 % mol), glucose (29 % mol), rhamnose (3% mol) and glucuronic acid (12% mol) as well as acetate (14.28 % mol), pyruvate (2.15 % mol) and succinate (1.80 % mol). Its content of water and ash was 15% p/p and 2% p/p, respectively, and the chemical bonds (determined by Infrared Spectroscopy - FT-IR) are consistent to the literature reports. However, due to limitations in Differential Scanning Calorimetry (DSC) equipment it was not possible to determine the glass transition temperature. In turn, the ionic liquid showed the typical behavior of a Newtonian fluid, glass transition temperature (determined by DSC) -98.03ºC and density 1.1031 g/cm3. The study of chemical bonds by FT-IR showed that amount of water (8.80%) influenced the visualization of the bands predicted to in view of their chemical structure. After the dissolution of the FucoPol in the ionic liquid at different temperatures (50, 60, 80 and 100 ° C) it was promoted the removal of this by the phase inversion method using deionized water as a solvent, followed by drying in an oven at 70 ° C. The mixtures before and after the phase inversion method were characterized through the studies mentioned above. In order to explore possible application field’s biocompatibility assays and collage on balsa wood tests were performed. It was found that the process of washing with water by the phase inversion method was not totally effective in removing the biocompatible ionic liquid, since all FucoPol – IL mixtures still contained ionic liquid in their composition as can be seen by the DSC results and FT-IR. In addition, washing the mixtures with water significantly altered the composition of FucoPol. However, these mixtures, that developed a viscous behavior typical of a non-Newtonian fluid (shear-thinning), have the potential to be applied in the biomedical field as well as biological glues.

Does ownership structure matter? Three essays in finance

Management

The Multidimensional and Centred Structure of Our Interested Perception in Hierocles

O objectivo desta dissertação é identificar a estrutura da percepção tal como ela é desenhada por Hiérocles nos <,(#= >1!(?$%&'(). Para alcançar este objectivo focar-me-ei na análise que o filósofo estóico leva a cabo em torno da percepção. O foco começa por incindir sobre a distinção entre percepção de si e percepção do exterior, com todas as suas subtilezas. Tal análise implicará então a consideração da importância da não-indiferença nessa estrutura de percepção. O objectivo é compreender como a percepção é sempre relacional e interessada. . Centrar-me-ei então na noção de !"#$%&'(), tentanto explorar a complexidade e multiplicidade do fenómeno em causa. Será também estabalecida a relação com o fragmento de Estobeu (6.671), que é, a par da obra, a fonte mais importante do pensamento de Hiérocles. Através desta relação introduzir-se-á a estrutura circular e concêntrica de uma percepção relacional e interessada. Toda esta dissertação será levada a cabo focando-se principalmente nos textos do próprio Hiérocles.

Inovcity- Structure of trials evaluation

In 2007, the UK government commissioned the Energy Demand Research Project to conduct a large scale experiment of smart metering technologies to test the impacts from many different forms of feedback to residential consumers. A full evaluation of the results was completed in 2011. In Portugal, EDP is also conducting smart meter trials in a project called InovCity in the city of Évora whose results will be evaluated during 2012. In this work, the case of Great Britain is studied as a reference on how an evaluation of trial results should be conducted. I also discuss potential limitations of the experiments, implications for national roll-out decisions, and finally draw some lessons that can be applied to the Portuguese case.

Impact of chromossomal structure on the evolution of Schizosaccharomyces pombe undergoing Mutation Accumulation

Large chromosomal rearrangements are common in natural populations and thought to be involved in speciation events. In this project, we used experimental evolution to determine how the speed of evolution and the type of accumulated mutations depend on the ancestral chromosomal structure and genotype. We utilized two Wild Type strains and a set of genetically engineered Schizosaccharomyces pombe strains, different solely in the presence of a certain type of chromosomal variant (inversions or translocations), along with respective controls. Previous research has shown that these chromosomal variants have different fitness levels in several environments, probably due to changes in the gene expression along the genome. These strains were propagated in the laboratory at very low population sizes, in which we expect natural selection to be less efficient at purging deleterious mutations. We then measured these strains’ changes in fitness throughout this accumulation of deleterious mutations, comparing the evolutionary trajectories in the different rearrangements to understand if the chromosomal structure affected the speed of evolution. We also tested these mutations for possible epistatic effects and estimated their parameters: the number of arising deleterious mutations per generation (Ud) and each one’s mean effect (sd).

Orthogonal models, structure crossing, nesting and inference

We intend to study the algebraic structure of the simple orthogonal models to use them, through binary operations as building blocks in the construction of more complex orthogonal models. We start by presenting some matrix results considering Commutative Jordan Algebras of symmetric matrices, CJAs. Next, we use these results to study the algebraic structure of orthogonal models, obtained by crossing and nesting simpler ones. Then, we study the normal models with OBS, which can also be orthogonal models. We intend to study normal models with OBS (Orthogonal Block Structure), NOBS (Normal Orthogonal Block Structure), obtaining condition for having complete and suffcient statistics, having UMVUE, is unbiased estimators with minimal covariance matrices whatever the variance components. Lastly, see ([Pereira et al. (2014)]), we study the algebraic structure of orthogonal models, mixed models whose variance covariance matrices are all positive semi definite, linear combinations of known orthogonal pairwise orthogonal projection matrices, OPOPM, and whose least square estimators, LSE, of estimable vectors are best linear unbiased estimator, BLUE, whatever the variance components, so they are uniformly BLUE, UBLUE. From the results of the algebraic structure we will get explicit expressions for the LSE of these models.

Chlorite Dismutase from perchlorate reducing bacteria. A potential biocatalyst to eliminate chlorinated species from polluted water resources and industrial wastes

Magnetospirillum (M.) sp. strain Lusitani, a perchlorate reducing bacteria (PRB), was previously isolated from a wastewater treatment plant and phylogenetic analysis was performed to classify the isolate. The DNA sequence of the genes responsible for perchlorate reduction and chlorite dismutation was determined and a model was designed based on the physiological roles of the proteins involved in the pcr-cld regulon. Chlorite dismutase (Cld) was purified from Magnetospirillum sp. strain Lusitani cells grown in anaerobiosis in the presence of perchlorate. The protein was purified up to electrophoretic grade using HPLC techniques as a 140 kDa homopentamer comprising five ~28 kDa monomers. Steady-state kinetic studies showed that the enzyme follows a Michaelis-Menten model with optimal pH and temperature of 6.0 and 5°C, respectively. The average values for the kinetic constants KM and Vmax were respectively 0.56 mM and 10.2 U, which correspond to a specific activity of 35470 U/mg and a turnover number of 16552 s-1. Cld from M. sp. strain Lusitani is inhibited by the product chloride, but not by dioxygen. Inhibition constants KiC= 460 mM and KiU= 480 mM indicated that sodium chloride is a weak mixed inhibitor of Cld, with a slightly stronger competitive character. The X-ray crystallography structure of M. sp. strain Lusitani Cld was solved at 3.0 Å resolution. In agreement with cofactor content biochemical analysis, the X-ray data showed that each Cld monomer harbors one heme b coordinated by a histidine residue (His188), hydrogen-bonded to a conserved glutamic acid residue (Glu238). The conserved neighboring arginine residue (Arg201) important for substrate positioning, was found in two different conformations in different monomers depending on the presence of the exogenous ligand thiocyanate. UV-Visible and CW-EPR spectroscopies were used to study the effect of redox agents, pH and exogenous ligands on the heme environment.

Garland, since 1776- a unique ownership structure

The case is based on Garland, a 240 years old Portuguese family business, now owned by the Dawson family. It focuses on a decision made 50 years ago, aligned with what had been the company’s history, about the ownership rules for family members, which influences the ownership structure of the firm. It addresses the main issues about ownership in family businesses, and tackles the problem of succession planning and fair process. It contains a teaching note to support the utilization of the case in a classroom context, with learning objectives, target audience, a teaching plan, questions and proposed answers, and theory that relates to the case. It is also complemented with an epilogue and an overview of the case.

A new credit monitoring framework for agents' networks

The purpose of this work is to develop a practicable approach for Telecom firms to manage the credit risk exposition to their commercial agents’ network. Particularly it will try to approach the problem of credit concession to clients’ from a corporation perspective and explore the particular scenario of agents that are part of the commercial chain of the corporation and therefore are not end-users. The agents’ network that served as a model for the presented study is composed by companies that, at the same time, are both clients and suppliers of the Telecommunication Company. In that sense the credit exposition analysis must took into consideration all financial fluxes, both inbound and outbound. The current strain on the Financial Sector in Portugal, and other peripheral European economies, combined with the high leverage situation of most companies, generates an environment prone to credit default risk. Due to these circumstances managing credit risk exposure is becoming increasingly a critical function for every company Financial Department. The approach designed in the current study combined two traditional risk monitoring tools: credit risk scoring and credit limitation policies. The objective was to design a new credit monitoring framework that is more flexible, uses both external and internal relationship history to assess risk and takes into consideration commercial objectives inside the agents’ network. Although not explored at length, the blueprint of a Credit Governance model was created for implementing the new credit monitoring framework inside the telecom firm. The Telecom Company that served as a model for the present work decided to implement the new Credit Monitoring framework after this was presented to its Executive Commission.

Does the existing Corporate Governance structure and strict Legal Framework, affect the strategic decisionmaking of CEOs?

This thesis is a case study on Corporate Governance and Business Ethics, using the Portuguese Corporate Law as a general setting. The thesis was conducted in Portugal with illustrations on past cases under the Business Judgment Rule of the State of Delaware, U.SA along with illustrations on current cases in Portugal under the Portuguese Judicial setting, along with a comparative analysis between both. A debate is being considered among scholars and executives; a debate on best practices within corporate governance and corporate law, associated with recent discoveries of unlawful investments that lead to the bankruptcy of leading institutions and an aggravation of the crisis in Portugal. The study aimed at learning possible reasons and causes for the current situation of the country’s corporations along with attempts to discover the best way to move forward. From the interviews and analysis conducted, this paper concluded that the corporate governance structure and legal frameworks in Portugal were not the sole influencers behind the actions and decisions of Corporate Executives, nor were they the main triggers for the recent corporate mishaps. But it is rather a combination of different factors that played a significant role, such as cultural and ethical aspects, individual personalities, and others all of which created gray areas beyond the legal structure, which in turn accelerated and aggravated the corporate governance crisis in the country.