Browsing by Author "Gomes, Pedro"
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- 3D-printed platform multi-loaded with bioactive, magnetic nanoparticles and an antibiotic for re-growing bone tissuePublication . Saraiva, Ana S.; Ribeiro, Isabel A. C.; Fernandes, Maria H.; Cerdeira, Ana Cláudia; Vieira, Bruno J.C.; Waerenborgh, João Carlos; Pereira, Laura C.J.; Cláudio, Ricardo; Carmezim, Maria João; Gomes, Pedro; Gonçalves, Lídia; Santos, Catarina F.; Bettencourt, AnaPolymeric platforms obtained by three-dimensional (3D) printing are becoming increasingly important as multifunctional therapeutic systems for bone treatment applications. In particularly, researchers aim to control bacterial biofilm on these 3D-platforms and enhance re-growing bone tissue, at the same time. This study aimed to fabricate a 3D-printed polylactic acid platform loaded with hydroxyapatite (HA), iron oxide nanoparticles (IONPs) and an antibiotic (minocycline) with tuneable properties and multistimuli response. IONPs were produced by a facile chemical co-precipitation method showing an average diameter between 11 and 15 nm and a superparamagnetic behaviour which was preserved when loaded into the 3D-platforms. The presence of two types of nanoparticles (IONPs and HA) modify the nanomorphological/nanotopographical feature of the 3D-platforms justifying their adequate bioactivity profile and in vitro cellular effects on immortalized and primary osteoblasts, including cytocompatibility and increased osteogenesis-related gene expression (RUNX2, BGLAP and SPP1). Disk diffusion assays and SEM analysis confirmed the effect of the 3D-platforms loaded with minocycline against Staphylococcus aureus. Altogether results showed that fabricated 3D-platforms combined the exact therapeutic antibiofilm dose of the antibiotic against S. aureus, with the enhanced osteogenic stimulation of the HA and IONPs nanoparticles which is a disruptive approach for bone targeting applications.
- Assessment of potential impacts in tourism of the increase in the average sea levelPublication . Gomes, Pedro; Gutierres, Francisco; Rocha, Jorge; Teodoro, Ana CláudiaClimate change and its effects are inevitable according to many authors; policies should be assumed regarding their mitigation and adaptation. Some economic sectors may suffer negative impacts, being tourism one with greater potential for impact. The increase in average sea level is one of the potential effects of climate change that can have consequences on tourism, particularly in the travel destinations that include coastal regions. The main objective of this work is to propose an approach for the assessment of potential impacts of the increase in the average sea level of tourism in a coastal area with a tripartite methodology. This methodology includes the assessment of physical vulnerability of the coast, including a coastal vulnerability index composed by nine physical variables – elevation, distance to shore, tide amplitude, significant wave weight, erosion/accretion rates, geology, geomorphology, ground cover vegetation and anthropogenic actions – followed by a quantification of coastal recession, based on the Bruun rule and the data of Special Report on Emissions Scenarios (SRES) developed by the Intergovernmental Panel on Climate Change (IPCC), on the rise in average sea level. Finally, it is estimated the total economic value of an area of recreation and tourism, based on the travel cost method. The proposed methodology was applied to a case study in the Portuguese coast, corresponding to the beach of São Jacinto, in Aveiro.
- Classification of daily abundant rainfall patterns and associated large-scale atmospheric circulation types in southern PortugalPublication . Fragoso, Marcelo; Gomes, PedroThe aim of this study is to carry out two objective classifications concerning the occurrence of episodes of heavy rainfall in Southern Portugal. The first one seeks to define the main spatial distribution patterns associated with abundant rainfall days in this region. Using a 15-year (from October 1983 to April 1998) precipitation data base corresponding to 98 sites in Southern Portugal, a sample is established by extracting the precipitation days in which the threshold of 40 mm/24 h was exceeded in three or more stations, yielding a total of 199 days. It is found that the Algarve region is the one where episodes of heavy rainfall are most frequent and which exhibits the strongest torrential character. The highest frequency of days with heavy rain occurs in the fall and in the early part of the winter. Through the combined use of principal component analysis (PCA) and k-means clustering, four different rainfall patterns are identified, and each one exhibits specific characteristics. The second classification is obtained using the same computational method (PCA coupled with k-means) and seeks to define the fundamental large-scale atmospheric circulation types associated with abundant rainfall in the region, based on sea level pressure (SLP) data. The data was collected from the NCEP/NCAR Reanalysis dataset, taking SLP as the most discriminating variable. Five circulation types are thus obtained, indicating considerable diversity among the large-scale atmospheric circulation conditions that are conducive to the occurrence of heavy rainstorms in Southern Portugal. The article concludes by discussing the main links between the two classification schemes, in order to ascertain the influence of the large-scale atmospheric circulation upon the spatial distribution patterns of heavy precipitation episodes.
- Colonialismo, classe e nação na história do automobilismo angolano (1957-1975)Publication . Gomes, PedroEste artigo propõe-se refletir sobre a relação entre o processo de ‘desportivização’ do automobilismo e as motivações que a elite local projetava sobre a modalidade, averiguando de que forma se coadunavam com a ideia da unidade do império. Procura-se explicar como os critérios sociais de entrada neste desporto foram evoluindo e como isso era revelador de rivalidades e dinâmicas económicas mais amplas que moviam os investidores a apostarem na modalidade para promover as suas marcas. A construção do Autódromo de Luanda e a internacionalização das ‘6 horas de Nova Lisboa’ ajudaram a popularizar a modalidade incentivando vínculos identitários locais que ora se articularam com os interesses do governo ora com interesses autonomistas de uma elite local.
- Do fiscal imbalances deteriorate sovereign debt ratings?Publication . Afonso, António; Gomes, PedroWe use sovereign debt rating estimations from Afonso, Gomes and Rother [2009, 2011] for Fitch, Moody’s, and Standard & Poor’s, to assess to what extent the recent fiscal imbalances are being reflected on the sovereign debt notations. With macro and fiscal data up to 2009, and macro and fiscal projections up to 2012, we obtain the expected rating for several oecd countries. The answer to the title question is yes, but in a diverse way for each country. Our average model predictions point to a heterogeneous behaviour of rating agencies across countries.
- Do fiscal imbalances deteriorate sovereign debt ratings?Publication . Afonso, António; Gomes, PedroWe use sovereign debt rating estimations from Afonso, Gomes and Rother (2009, 2010) for Fitch, Moody’s, and Standard & Poor’s, to assess to what extent the recent fiscal imbalances are being reflected on the sovereign debt notations. We use macro and fiscal data up to 2009, and macro and fiscal projections, to obtain the expected rating for several OECD countries. The answer to the title question is yes, but in a diverse way for each country. Our average model predictions point to a heterogeneous behaviour of rating agencies across countries.
- Engineering a multifunctional 3D-printed PLA-collagen-minocycline-nanoHydroxyapatite scaffold with combined antimicrobial and osteogenic effects for bone regenerationPublication . Martin, Victor; Ribeiro, Isabel A. C.; Alves, Marta M.; Gonçalves, Lídia; Claudio, Ricardo A.; Grenho, Liliana; Fernandes, Maria H.; Gomes, Pedro; Santos, Catarina F.; Bettencourt, Ana3D-printing and additive manufacturing can be powerful techniques to design customized structures and produce synthetic bone grafts with multifunctional effects suitable for bone repair. In our work we aimed the development of novel multifunctionalized 3D printed poly(lactic acid) (PLA) scaffolds with bioinspired surface coatings able to reduce bacterial biofilm formation while favoring human bone marrow-derived mesenchymal stem cells (hMSCs) activity. For that purpose, 3D printing was used to prepare PLA scaffolds that were further multifunctionalized with collagen (Col), minocycline (MH) and bioinspired citrate- hydroxyapatite nanoparticles (cHA). PLA-Col-MH-cHA scaffolds provide a closer structural support approximation to native bone architecture with uniform macroporous, adequate wettability and an excellent compressive strength. The addition of MH resulted in an adequate antibiotic release profile that by being compatible with local drug delivery therapy was translated into antibacterial activities against Staphylococcus aureus, a main pathogen associated to bone-related infections. Subsequently, the hMSCs response to these scaffolds revealed that the incorporation of cHA significantly stimulated the adhesion, proliferation and osteogenesis-related gene expression (RUNX2, OCN and OPN) of hMSCs. Furthermore, the association of a bioinspired material (cHA) with the antibiotic MH resulted in a combined effect of an enhanced osteogenic activity. These findings, together with the antibiofilm activity depicted strengthen the appropriateness of this 3D-printed PLA-Col-MH-cHA scaffold for future use in bone repair. By targeting bone repair while mitigating the typical infections associated to bone implants, our 3D scaffolds deliver an integrated strategy with the combined effects further envisaging an increase in the success rate of bone-implanted devices.
- "Folclore" e "ritmos modernos" na cidade colonial - classe, raça e nação na história da música urbanda de LuandaPublication . Gomes, PedroEste capítulo explora a relação entre as noções de moderno e tradicional na disseminação do pop-rock e do semba na malha urbana da Luanda colonial. Neste âmbito, focam-se as práticas musicais e expressivas de ambos os géneros, os seus consumos e a sua articulação com processos de diferenciação social (económica, espacial, racial e simbólica).3 Com base nas memórias de habitantes de Luanda, principalmente dos que viviam na periferia da cidade, e de produtores musicais, nomeadamente músicos, relaciona as fronteiras conflitos e parcerias que definiriam estes géneros com as lógicas do mercado instituídas pelos circuitos das salas de espetáculos e salões de baile e com as políticas culturais da administração colonial, às quais estiveram, por vezes, interligadas.
- Genetic diversity of candidate loci linked to Mycobacterium tuberculosis resistance to bedaquiline, delamanid and pretomanidPublication . Gómez-González, Paula J.; Perdigão, João; Gomes, Pedro; Puyen, Zully M.; Santos-Lazaro, David; Napier, Gary; Hibberd, Martin L.; Viveiros, Miguel; Portugal, Isabel; Campino, Susana; Phelan, Jody; Clark, Taane G.Tuberculosis (TB), caused by Mycobacterium tuberculosis, is one of the deadliest infectious diseases worldwide. Multidrug and extensively drug-resistant strains are making disease control difficult, and exhausting treatment options. New anti-TB drugs bedaquiline (BDQ), delamanid (DLM) and pretomanid (PTM) have been approved for the treatment of multi-drug resistant TB, but there is increasing resistance to them. Nine genetic loci strongly linked to resistance have been identified (mmpR5, atpE, and pepQ for BDQ; ddn, fgd1, fbiA, fbiB, fbiC, and fbiD for DLM/PTM). Here we investigated the genetic diversity of these loci across >33,000 M. tuberculosis isolates. In addition, epistatic mutations in mmpL5-mmpS5 as well as variants in ndh, implicated for DLM/PTM resistance in M. smegmatis, were explored. Our analysis revealed 1,227 variants across the nine genes, with the majority (78%) present in isolates collected prior to the roll-out of BDQ and DLM/PTM. We identified phylogenetically-related mutations, which are unlikely to be resistance associated, but also high-impact variants such as frameshifts (e.g. in mmpR5, ddn) with likely functional effects, as well as non-synonymous mutations predominantly in MDR-/XDR-TB strains with predicted protein destabilising effects. Overall, our work provides a comprehensive mutational catalogue for BDQ and DLM/PTM associated genes, which will assist with establishing associations with phenotypic resistance; thereby, improving the understanding of the causative mechanisms of resistance for these drugs, leading to better treatment outcomes.
- Interactions between private and public sector wagesPublication . Afonso, António; Gomes, PedroWe examine the interactions between public and private sector wages per employee in OECD countries. The growth of public sector wages and of public sector employment positively affects the growth of private sector wages. Moreover, total factor productivity, the unemployment rate and the degree of urbanisation are also important determinants of private sector wage growth. With respect to public sector wage growth, we find that it is influenced by fiscal conditions in addition to private sector wages. We then set up a dynamic labour market equilibrium model with two sectors, search and matching frictions and exogenous growth to understand the transmission mechanisms of fiscal policy. The model is quantitative consistent with the main estimation findings.
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