Browsing by Issue Date, starting with "2017-12-12"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Reabilitação do entreposto frigorífico do Funchal: um caso de estudoPublication . Cassiano, Roberto Jesus; Lobo, Paulo Renato Camacho da Silva; Correia, Luís Miguel GouveiaA presente dissertação insere-se na área de reabilitação e reparação de estruturas de betão armado, fortemente atacadas pelo ambiente marítimo. Avaliando a viabilidade de reparação de uma obra marítima, este estudo conta com os fatores que causam a deterioração do betão armado e todo o estudo a realizar, para entendimento de uma estrutura desse tipo. Estudaram-se as patologias mais associadas ao ambiente marítimo, nomeadamente a corrosão por ataque cloretos e dissolução de finos por ataque da água do mar, assim como os efeitos resultantes da exploração da estrutura. Realizaram-se inspeções, nomeadamente preliminar e básica, para compreensão das plantas estruturais, levantamento de patologias, planeamento e execução da inspeção especial, onde foram retiradas amostras de betão em pontos por toda a estrutura. Completando a informação, apresentam-se os resultados dos ensaios de laboratório, com análise e interpretação dos mesmos, associando à exploração da estrutura. Concluindo, é estudada uma solução de reparação, assim como um sistema de escoramento, de modo a possibilitar a reparação em segurança.
- Preliminary studies on the use of exosomes as dendrimer carriersPublication . Olim, José Filipe Sousa de; Tomás, Helena Maria Pires Gaspar; Rodrigues, João Manuel CunhaEukaryotic and prokaryotic cells can release vesicles into the biological fluids that differ in size and mechanism of biogenesis. In recent years, particular attention has been paid to exosomes which are naturally occurring nanoparticles (50 – 150 nm) that have been found in various biological fluids and are recognized as having an important role in intercellular communication and other biological processes. Human mesenchymal stem cells (hMSCs) are multipotent cells that can be found in different tissues in the adult. hMSCs have a large capacity for ex vivo expansion and show immunosuppressive properties, making them the ideal source of exosomes for biomedical applications. Dendrimers are nanoscale molecules that have promising properties as drug/gene delivery vehicles and, as such, their inclusion inside hMSCs exosomes may be a way for their easier spreading and target reaching in the body. The present work was focused on the hypothesis that exosomes can be loaded before their isolation from cells by simple cell exposure to dendrimers. First, dendrimers were labelled with rhodamine and then characterized by 1H NMR, FTIR, UV/Vis spectroscopy, and fluorescence spectroscopy. Then, the effect of the pH in the stability of the fluorescence emission of these conjugates was study, as well as their cytotoxicity behavior and kinetics of cellular internalization. After, a protocol for exosome isolation was established using a precipitation-based approach and the isolated exosomes were characterized by DLS, TEM and acetylcholinesterase activity. hMSCs were then exposed to a solution containing the labelled dendrimers and the released exosomes were collected to evaluate the presence of the dendrimers inside. Contrary to what was expected, the dendrimers were not excreted inside exosomes and, instead, were accumulated in the cellular perinuclear zone. By fluorescence microscopy and using specific biochemical markers, it was possible to co-localize the conjugated dendrimers with the Golgi complex and the endoplasmic reticulum.