Browsing by Issue Date, starting with "2013-01"
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- Consultas médicas por telefone e e-mail: gestão da informação nas unidades de saúdePublication . Santos, Nuno Miguel Venceslau Correia dos; Pinheiro, Paulo GonçalvesA ineficiência conduz à iniquidade e aumento dos custos (Campos 2007). Estas exigências de eficácia são agravadas pelo aumento das listas de espera para consultas em Portugal, sistemas informáticos pouco desenvolvidos no campo da saúde e extensa burocracia para obter consulta médica (Campos, Saturno & Carneiro, 2010; Furtado & Pereira, 2010). Torna-se, portanto, cada vez mais necessária a adaptação das unidades de saúde às tecnologias da comunicação. O objectivo principal deste trabalho foi avaliar as atitudes da população portuguesa relativamente à obtenção do número e endereço de correio electrónico do médico. Adicionalmente, compararam-se as atitudes face ao e-mail e ao telefone, bem como a influência das variáveis sociodemográficas nestas atitudes. Foi aplicado um questionário online traduzido e adaptado de Peleg e Nazarenko (2012). Este questionário foi difundido através de correio electrónico e das redes sociais Facebook® e Linkedin®. Esta difusão foi realizada pela plataforma encuestafacil. Assim a população alvo consistiu em cibernautas cujo único requisito para responderem ao questionário era terem 18 ou mais anos, no total responderam 222 pessoas. Os dados foram tratados através do SPSS® realçando os itens mais cotados em relação às atitudes e procurando possíveis correlações entre variáveis demográficas e atitudes para com a consulta médica por telefone e e-mail. Os resultados evidenciam atitudes mais positivas face ao telefone, ainda que também se evidenciem alguns aspetos em que o acesso ao e-mail é percepcionado de forma mais positiva que ao telefone. O acesso ao telefone aumenta a sensação de segurança (mesmo que não o utilizem) e é visto como eficaz na resolução dos problemas. Contudo, consideram que o telefone pode interferir com a privacidade do médico, podendo ainda elevar a possibilidade de um erro de comunicação ou mal-entendido. As maiores vantagens do e-mail referidas pelos inquiridos foram o facto de não interromper o trabalho do médico, a possibilidade de diminuir o número de consultas e que aumentaria a sensação de segurança dos utentes, os inconvenientes do e-mail são semelhantes aos do telefone. Conclui-se que apesar de existirem atitudes mais positivas em relação às consultas por telefone, são necessários mais estudos na população de forma a adaptar uma futura implementação à mesma. Sugere-se ainda em termos de gestão das unidades hospitalares que a implementação deste tipo de consultas não presenciais seja acompanhada de formação específica que incida em técnicas de comunicação, da fundação de unidades orgânicas com a função de orientar e regular estes sistemas de comunicação entre médico e utente e ainda da melhoria de bases dados para que estas consultas sejam completamente seguras e eficazes.
- Characterization of the Mechanical and Biological Properties of a New Alumina ScaffoldPublication . Batista, Patrícia Sofia Pinhanços; Rodrigues, Miguel; Silva, Daniela; Morgado, Patrícia I.; Henriques, J.; Almeida, Maria; Silva, Abílio P.; Correia, Ilídio Joaquim SobreiraPurpose: In this work, an alumina scaffold was produced through a new method to be used in a near future as a bone substitute. Methods: In vitro and in vivo studies were performed in order to characterize the mechanical and biological properties of the scaffold. Results: the results obtained showed that this scaffold has high mechanical resistance and a porous surface that allows human osteoblast cells to adhere and proliferate. the in vivo studies revealed no systemic reaction. Conclusions: the alumina scaffold produced herein has the mechanical and biological properties that are compatible with its application in bone therapy.
- Development of a New Dynamic Liquid Film Extension and Integration into a Spray Impingement ModelPublication . Rodrigues, Christian; Barata, Jorge M M; Silva, AndréThis paper is concerned with the improvement of macroscopic spray impingement simulations, for which a sub-model has been proposed for the formation of the liquid film over the impingement wall due to the deposition of particles. This computational extension deals with the interaction and spreading of the liquid between adjacent nodes due to the dynamic motion induced by the film inertia and crossflow velocity, as well as, the exchange of mass between incident drops, secondary droplets and liquid film. Moreover, an empirical correlation deduced from experimental data is used to define the relative liquid film thickness. Experimental data are used to validate the numerical model. Good agreement is obtained between numerical and experimental results for the test cases performed. The distribution of the relative liquid film thickness for two cases of crossflow velocities are also illustrated, as well as, its temporal evolution from start of injection. The dynamic behavior of the layer proved to be in concordance with the observations reported in experimental investigations available in the literature.
- Numerical and Experimental Study of Two Impinging Jets in a Row through a CrossflowPublication . Vieira, Diana; Silva, André; Neves, Fernando M. S. P.; Carvalho, Pedro dos Santos Duarte; Barata, Jorge M MAn experimental and numerical study is carried out to investigate the flowfield created by twin impinging jets aligned with a low velocity crossflow. The mean velocity, velocity fluctuation and visualization in the impingement region were obtained for a Reynolds number based on the jet exit conditions of Rej=4.3x104, an impingement height of 20.1 diameter and for a velocity ratios between the jet exit and the crossflow VR=Vj/Uo of 22.5, 33.7 and 43.8 with interject spacing, S of 6D. The experimental results show a large penetration of the first (upstream) impinging jet, giving rise to a ground vortex due to the collision of the radial wall jet and the crossflow that wraps around the impinging point like a scarf. The second jet (located downstream) it is not so affected by the crossflow in terms of deflection, but it does not reach the ground due to the downstream wall jet that flows radially from the impinging point of the first jet along the ground. The results indicate a new flow pattern not yet reported so far, in which a VSTOL aircraft operating in ground vicinity with front wind or small forward movement may result in enhanced negative pressures in the underside of the aircraft causing a pitching moment and a suction down force towards the ground. To extend the experimental results, the flow was also numerically simulated using a Reynolds Averaged Navier-Stokes formulation with the "k-ε" turbulence model.
- Microencapsulated chitosan–dextran sulfate nanoparticles for controled delivery of bioactive molecules and cells in bone regenerationPublication . Valente, Joana; Gaspar, Vítor Manuel Abreu; Antunes, Bernardo Paiva; Coutinho, Paula Isabel Teixeira Gonçalves; Correia, Ilídio Joaquim SobreiraThis research work aimed to synthesize and characterize a novel dual delivery system comprised of BSA-loaded in chitosan–dextran sulfate nanoparticulated carriers and mesenchymal stem cells that are encapsulated into alginate microparticles. The physicochemical and biological characteristics of this novel system, such as, morphology, release, swelling, and cytotoxicity were thoroughly characterized. The results obtained from confocal microscopy demonstrate that chitosan–dextran sulfate nanoparticles and cells are fully encapsulated within alginate microparticles, and spatially dispersed in the microparticle matrix. Moreover, scanning electron microscopy images revealed that these micro-sized carriers possess a rough surface, an important parameter that also promoted proper cell migration and adhesion. Notably, the incorporation of BSA in this duplex nano-micro delivery system extended its release profile throughout time, in comparison with microparticles alone, whilst not eliciting any cell damage. Taken together, these findings suggest that this dual carrier is a versatile delivery system with potential for a spatiotemporally controlled release of bioactive molecules and cells.
- Dual on–off and off–on switchable oligoaziridine biosensorPublication . Raje, Vivek; Morgado, Patrícia I.; Ribeiro, MP.; Correia, Ilídio Joaquim Sobreira; Bonifácio, Vasco; Branco, Paula S.; Ricardo, Ana AguiarA water-soluble biocompatible aziridine-based biosensor with pendant anthracene units was synthesized by radicalar polymerization of N-substituted aziridines in supercritical carbon dioxide. The binding ability of the sensor towards a series of metal ions was examined by comparing the fluorescence intensities of the solutions before and after the addition of 100 equivalents of a solution of the metal ion chloride salt. A fast, simple and highly optical sensitive dual behavior, “off–on” and “on–off” response, was observed after the biosensor was exposed to the metal cations in aqueous solution. Zinc presented the highest fluorescence enhancement (turn-on) and copper presented the highest fluorescence quenching (turn-off). The response time was found to be instantaneous and the detection limit was achieved even in the presence of excess metal cation competitors. By using immunofluorescence microscopy it was also shown that oligoaziridine acts as an “on–off” probe through highly sensitive (detection limit of 1.6 nM), selective and reversible binding to copper anions under physiologic conditions using living Human Fibroblast cells. The stoichiometry for the reaction of the biosensor with Cu2+ was determined by a Job plot and indicates the formation of an oligoaziridine-Cu2+ 1:2 adduct.
- Sensitive Detection of Peptide–Minicircle DNA Interactions by Surface Plasmon ResonancePublication . Gaspar, Vítor Manuel Abreu; Cruz, Carla Patrícia Alves Freire Madeira; Queiroz, João; Pichon, Chantal; Correia, Ilídio; Sousa, FaniMinicircle DNA (mcDNA) is recently becoming an exciting source of genetic material for therapeutic purposes due to its exceptional biocompatibility and efficiency over typical DNA. However, its widespread use is yet restrained because of the absence of an efficient technology that allows its purification. Here, the precise conditions of mcDNA interaction with novel arginine-arginine dipeptide ligands were explored to promote binding and recovery of these biopharmaceuticals. Such interactions were investigated by taking advantage of a highly sensitive method based on surface plasmon resonance (SPR) to screen, in real-time, for ligand-coupled biomolecules, while preserving mcDNA integrity. Through this analytic approach, we detected dynamic binding responses that are dependent on buffer type, mcDNA electrokinetic potential, and temperature conditions. Remarkably, the results obtained revealed that the ligands possess high affinity to mcDNA molecules under low salt buffers, and low affinity in the presence of salt, suggesting that electrostatic interactions mainly govern ligand–analyte coupling. These findings provide important insights for an active manipulation of parameters that promote mcDNA recovery and purification. Above all, this study showed the crucial importance of SPR for future screening of other ligands that, like the one described herein, can be used to design mcDNA recovery platforms which will have significant impact in biopharmaceutical-based therapeutics.
- Poly(ester amide)s based on (L)-lactic acid oligomers and α-amino acids: influence of the α-amino acid side chain in the poly(ester amide)s propertiesPublication . Fonseca, Ana; Coelho, Jorge; Valente, Joana; Correia, Tiago R.; Correia, Ilídio Joaquim Sobreira; Gil, Maria; Simões, PedroNovel biodegradable and low cytotoxic poly(ester amide)s (PEAs) based on α-amino acids and (L)-lactic acid (L-LA) oligomers were successfully synthesized by interfacial polymerization. The chemical structure of the new polymers was confirmed by spectroscopic analyses. Further characterization suggests that the α-amino acid plays a critical role on the final properties of the PEA. L-phenylalanine provides PEAs with higher glass transition temperature, whereas glycine enhances the crystallinity. The hydrolytic degradation in PBS (pH = 7.4) at 37 °C also depends on the α-amino acid, being faster for glycine-based PEAs. The cytotoxic profiles using fibroblast human cells indicate that the PEAs did not elicit an acute cytotoxic effect. The strategy presented in this work opens the possibility of synthesizing biodegradable PEAs with low citotoxicity by an easy and fast method. It is worth to mention also that the properties of these materials can be fine-tuned only by changing the α-amino acid.
- Experimental Study of a Ground Vortex: The Effect of the Crossflow VelocityPublication . Barata, Jorge M M; Bernardo, Nuno; Santos, Pedro José da Costa Teixeira; Silva, AndréThe study of the complex flowfield produced by a single jet impinging on a wall through a crossflow has been carried out over the past several decades with many different motivations and applications. This type of flow is most relevant to the successful design and operation of vertical and/or short take-off and landing aircrafts. The increased momentum of the wall jet is consistent with the movement of the separation point in the X direction, but the region of higher mean vertical velocity spreads in the wall direction. Nevertheless, their results did not exhibit any bimodal LDV histograms of discrete frequencies that could be associated with any instabilities or oscillations. To avoid the influence of the impinging region, a plane wall jet is produced independently. The wall jet collides with the boundary layer produced using a conventional wind tunnel giving rise to a highly curved region, which can be studied for different velocity ratios between the wall jet and crossflow.