O presente trabalho tem como foco a análise da entrada de turistas no território e nas fronteiras Angolanas bem como o seu potencial de impacto no País. Neste sentido, pretende-se como principal objetivo analisar entre outros assuntos, a evolução da taxa de receita do turismo em Angola entre os anos de 2012 e 2017. Para a concretização desta investigação foram também delineados alguns objetivos secundários, nomeadamente: (i) análise da previsão da evolução da economia e (ii) análise dos principais indicadores do Turismo, de forma a analisar os seus efeitos na economia. Para atingir os objetivos traçados utilizou-se uma metodologia de caráter qualitativa apoiada numa profunda recolha de dados efetuada através de revistas, livros, artigos científicos e bases de dados como aconteceu com a WTTC. Em termos de conclusão, verificou-se que perante os desafios que Angola enfrenta, o turismo aparece como uma atividade com algum potencial de desenvolvimento alternativo do território. Neste sentido, as autoridades angolanas, deverão procurar maximizar o seu potencial através de uma cuidadosa gestão das receitas geradas pelo turismo, da abertura de hotéis, criação de restaurantes e também através de vários meios complementares facilitando assim uma maior geração de emprego entre outros fatores.

O objetivo da dissertação visa conceber, implementar e avaliar um sistema para acesso, gestão e pesquisa confiável de dados privados mantidos em nuvens de armazenamento de provedores Internet (ou Internet Cloud-Storage Solutions). O sistema (que designaremos por T-Stratus), preserva garantias de autenticidade, privacidade, fiabilidade, disponibilidade dos dados e tolerância a intrusões, sob controlo dos utilizadores e de forma independente dos provedores. O sistema T-Stratus atua como base de confiança para indexação, encriptação e distribuição de dados em múltiplas nuvens de armazenamento, permitindo o acesso aos mesmos para leitura, escrita e pesquisa em tempo real. O armazenamento distribuído dos dados faz-se por um processo de fragmentação e replicação, sendo os fragmentos cifrados e replicados em múltiplas nuvens de armazenamento. A arquitetura do sistema T-Stratus, concebida como sistema middleware, permite o seu uso como serviço intermediário entre utilizadores individuais e múltiplas nuvens de armazenamento, numa solução de nuvem de nuvens. A solução pretende tirar partido das vantagens da manutenção e replicação de dados privados em múltiplos provedores Internet, com controlo da base de confiança que assegura as propriedades de segurança e confiabilidade. A avaliação experimental do sistema proposto envolve a obtenção de métricas de latência e de taxas de transferência de dados em escrita e leitura, comparando a eficiência da solução com a utilização, considerada não segura e não confiável, das atuais soluções de armazenamento em nuvens na Internet.

This work reports research on the development of bimodal magnetic and fluorescent 1D nanoprobes. First, ferromagnetic nickel nanowires (NiNW) have been prepared by Ni electrodeposition in an anodic aluminum oxide (AAO) template. The highly ordered self-assembled AAO nanoporous templates were fabricated using a two-step anodization method of aluminum foil. The surface of the NiNW were then modified with polyethyleneimine (PEI) which was previously labeled with an organic dye (fluorescein isothiocyanate: FITC) via covalent bonding. The ensuing functionalized NiNW exhibited the characteristic green fluorescence of FITC and could be magnetically separated from aqueous solutions by using a NdFeB magnet. Finally, the interest of these bimodal NiNW as nanoprobes for in vitro cell separation and biolabeling was preliminary assessed in a proof of principle experiment that involved the attachment of bio-functionalized NiNW to blood cells. (C) 2013 Elsevier Inc. All rights reserved.

This work reports research on the development of bimodal magnetic and fluorescent 1D nanoprobes. First, ferromagnetic nickel nanowires (NiNW) have been prepared by Ni electrodeposition in an anodic aluminum oxide (AAO) template. The highly ordered self-assembled AAO nanoporous templates were fabricated using a two-step anodization method of aluminum foil. The surface of the NiNW were then modified with polyethyleneimine (PEI) which was previously labeled with an organic dye (fluorescein isothiocyanate: FITC) via covalent bonding. The ensuing functionalized NiNW exhibited the characteristic green fluorescence of FITC and could be magnetically separated from aqueous solutions by using a NdFeB magnet. Finally, the interest of these bimodal NiNW as nanoprobes for in vitro cell separation and biolabeling was preliminary assessed in a proof of principle experiment that involved the attachment of biofunctionalized NiNW to blood cells.

Endophthalmitis, an inflammation of the eye due to perioperative infection, may occur after cataract surgery. Intraocular lenses (IOLs) loaded with an antibiotic have been proposed as an alternative to the conventional postoperative endophthalmitis prophylaxis, since the antibiotic is delivered directly to the target site. In this work, an IOL-based antibiotic releasing system was prepared from a copolymer used in the production of IOLs and a fluoroquinolone used in endophthalmitis prophylaxis (moxifloxacin, MFX). Argon plasma-assisted grafting with 2-hydroxyethyl methacrylate (HEMA) in the presence of MFX was the approach selected for surface modification, with MFX loaded both by entrapment in the grafted polyHEMA coating and by soaking. Surface and bulk properties were evaluated before and after surface modification and the MFX release profiles were obtained both in batch mode (sink conditions) and under hydrodynamic conditions, employing a purpose-built microfluidic cell, which simulated the hydrodynamic conditions around the eye lens. The effect of storage on the release profile of the best system was also assessed. The best system released MFX for ca. 15 days above the minimum inhibitory concentration for Staphylococcus aureus and Staphylococcus epidermidis. The released MFX showed antimicrobial activity against these bacteria and was non-cytotoxic against corneal endothelial cells.

Intraocular lenses (IOLs) present an alternative for extended, local drug delivery in the prevention of post-operative acute endophthalmitis. In the present work, we modified the surface of a hydrophilic acrylic material, used for manufacturing of IOLs, through plasma-assisted grafting copolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), with the aim of achieving a controlled and effective drug release. The material was loaded with moxifloxacin (MFX), a commonly used antibiotic for endophthalmitis prevention. The characterization of the modified material showed that relevant properties, like swelling capacity, wettability, refractive index and transmittance, were not affected by the surface modification. Concerning the drug release profiles, the most promising result was obtained when AMPS grafting was done in the presence of MFX. This modification led to a higher amount of drug being released for a longer period of time, which is a requirement for the prevention of endophthalmitis. The material was found to be non-cytotoxic for rabbit corneal endothelial cells. In a second step, prototype IOLs were modified with AMPS and loaded with MFX as previously and, after sterilization and storage (30 days), they were tested under dynamic conditions, in a microfluidic cell with volume and renovation rate similar to the eye aqueous humour. MFX solutions collected in this assay were tested against Staphylococcus aureus and Staphylococcus epidermidis and the released antibiotic proved to be effective against both bacteria until the 12th day of release.

Magnetic hydrogel κ-carrageenan nanospheres were successfully prepared via water-in-oil (w/o) microemulsions combined with thermally induced gelation of the polysaccharide. The size of the nanospheres (an average diameter ( ) of about 50 and 75 nm) was modulated by varying the concentration of surfactant. The nanospheres contained superparamagnetic magnetite nanoparticles ( 8 nm), previously prepared by co-precipitation within the biopolymer. Carboxyl groups, at a concentration of about 4 mmol g−1, were successfully grafted at the surface of these magnetic nanospheres via carboxymethylation of the κ-carrageenan. The carboxylated nanospheres were shown to be thermo-sensitive in the 37–45 ◦C temperature range, indicating their potential as thermally controlled delivery systems for drugs and/or magnetic particles at physiological temperatures. Finally, preliminary results have been obtained for IgG antibody conjugation of the carboxylated nanospheres and the potential of these systems for bio-applications is discussed.