CDRsp - Comunicações em conferências internacionais
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- Adhesion, proliferation and distribution of human mesenchymal stem/stromal cells (MSCs) in Poly(ɛ -caprolactone) (PCL) scaffolds with different pore sizesPublication . Moura, C. S.; Biscaia, S.; Viana, T.; Bártolo, P. J.; Silva, C. L. da; Cabral, J. S.; Ferreira, F. C.Tissue engineering, combining the use of biomaterials, mesenchymal stem/stromal cells (MSCs) and optimized culture medium formulations, is a very promising research field for tissue regeneration. This work is focused on the application of Poly(ε-caprolactone) scaffolds designed to have a spacing gradient between orthogonal fibres with diameters of 0.3mm with pore sizes ranging from 190 to 390 μm. Human bone marrow (BM)-derived MSCs, were used to evaluate cell adhesion, proliferation and distribution within the scaffolds. Specifically, we hypothesized if seeding MSC in scaffold regions with different pore sizes would influence cell proliferation. Therefore, MSC were seeded at the centre of scaffolds with either larger (390 μm) or smaller pores (190 μm). Results obtained showed similar levels of adhesion and proliferation in both configurations, with fold increase in total cell number of 5 after 13 days of cultivation; which indicates that no limitation for cell proliferation within the range of pore sizes studied is observed.
- Materials characterization for stereolithographyPublication . Camaño, Patricia; Bartolo, Paulo J.Stereolithography is an additive technology that allows the fabrication of three-dimensional macro and micro-parts for industrial and medical applications. By solidifying a liquid photo-sensitive monomer with a laser or UV-light source a polymeric part is built up layer by layer. The use of highly reinforced polymeric systems with metallic or ceramic particles also enables to transform this rapid prototyping technology into a rapid manufacturing one. The quality and fabrication speed of stereolithographic parts strongly depends on the curing kinetics. Therefore it is crucial to optimize the polymeric mixture for a specific application. This research work investigates the curing kinetics of reinforced and non-reinforced unsaturated polyester resins with different photo-initiator concentrations. Two types of particles were considered: tungsten carbide and hydroxyapatite (concentrations of 30 wt%).
- BioFab toolbox – Software tools for biofabricationPublication . Alves, N.; Bártolo, P.; Ferreira, N.; Gaspar, M.; Mateus, A.This is a progress report of a project called BioFab Toolbox, funded by the Portuguese National Science Foundation, consisting of the development of a collection of software tools to assist in the process of rapid prototyping and rapid manufacturing of new products. This project is especially designed to produce scaffolds, grafts, implants and other medical applications usually designated as biofabrication (biofab).
- Direct writing of conductive polymer tracks as part of an additive manufacturing processPublication . Mitchell, G. R.; Davis, Fred J.The use of electrically conductive polymers to construct hetereogenous structures via additive manufacturing is an attractive possibility. It maintains the all polymeric nature of such structures. In this work we discuss how this might be achieved in practical additive manufacturing equipment.
- Structure development during additive manufacturingPublication . Tojeira, A.; Biscaia, S.; Viana, T.; Bártolo, P. J.; Mitchell, G. R.Additive manufacturing involves the shaping of a product through the use of a liquid phase which is subsequently transformed to the solid state by cooling or through the use of chemical cross-linking reactions. Of particular note is the fused deposition modeling which utilizes semi-crystalline polymers such as poly(ε-caprolactone) or poly(lactic acid) and has been employed in CDRsp to prepare highly porous scaffolds for Tissue Engineering. We show that the crystallization process amplifies small levels of molecular anisotropy introduced in the additive writing process. We show that the level of anisotropy is significantly dependent on the process parameters such as temperature, write speed, and flow rate. The differences in the crystalline morphology introduced by changing these process parameters will have a marked impact on the mechanical properties. This in turn will alter the growth of tissue on such scaffold structures. As with other polymer processing procedures, tuning the process parameters provides a route to controlling and defining the structure and morphology of the scaffold and the properties exhibited by that scaffold.
- Innovative developments on Agile-CAD systemPublication . Gaspar, M.; Alves, N.; Martins-Ferreira, N.; Bártolo, P.Agile-CAD is a reverse engineering computer tool that allows the recovering of outer and inner 3D shapes of existing objects of revolution with constant thickness, using silhouettes computed from one or two digital views. In this context, some improved algorithms were developed in order to provide more accurate and robust tridimensional reconstruction when using a single digital image as source. Experimental results based on real images are presented, demonstrating the good performance of this computer tool.
- Optimizing regions for characterization of thermal images in medical applicationsPublication . Duarte, A.; Carrão, L.; Espanha, M.; Viana, T.; Freitas, D.; Bártolo, P.; Faria, P.; Almeida, H.Biomedical techniques and applications are being developed and placed at the service of clinicians. An example is medical thermography which is being used more often in the detection of certain diseases and also in pain distribution. Current thermography processing software has some limitations mainly because it is developed for general applications and doesn't allow the identification of a Region Of Interest (ROI) with a specific anatomic shape. In this research, a computational application was developed in order to aid in the characterization of thermal images. The limitations of existing software applications was overcome by designing an application that allows choosing any ROI, independently of its geometric shape, making the analysis, processing and comparison of different thermal images, easier to be used by the medical community.
- Soccer sprint and agility are similar between pre- and postpubescent boys, when ball is consideredPublication . Morouço, P.G.; Dias, R.; Menino, V.Introduction Scientific evidence suggests that specific physiological demands and anthropometrical prerequisites result in the selection of young players based onenhanced physiological performances and anthropometricaladvantage (1). How-ever, the competitive demands are not the same in youth categories, inducing different physical and physiological profiles from those of adult players (2). The purpose of the present study was to analyze possible differences in speed, agility and jump height of pre- and postpubescent soccer players.
- Strength or technique: What should be trained to increase swimming speed?Publication . Morouço, P.G.; Marinho, D.A.; Marques, M.C.Introdution Swimming speed is both dependent on strength and technique. Indeed, the balance between these two major factors may explain the success or failure in competitive events. However, competitive events vary enormously in terms of distance, and therefore time and intensity. Thus, an optimal level of strength is essential for successful performance in swimming (1), varying according to the distance to be swam (2). But how can swimming coaches track the balance between these two factors? And how can be identified if the swimmer must focus in one of them, in detriment of the other?
- The influence of knowledge management on the result of innovation of companies in the mold industriesPublication . Ferreira, Vítor Hugo Santos; Marques, Alzira Maria Ascensão; Espírito Santo, Pedro Manuel do; Silva, Sara Fernandes daIn today's business world, knowledge and innovation are key factors for the success of organizations. Knowledge stock alone does not generate a competitive advantage to companies, but the way it is used might create it. It is through the wide network of relationships that involves the organization that innovations emerge. These two concepts are intertwined, since for the innovation process to be successful, there must first be an effective knowledge management, which involves knowledge acquisition, application and sharing. In this context and based on a sample of 36 companies in the mold making sector in Portugal (one industry where Portugal is the 8th top producer in the world), a confirmatory research work was carried out with the aim of studying the impact of knowledge management on innovation performance. For this purpose, we used a quantitative methodology based on a survey. Through the estimation of a structural equations model, using SmartPLS software, we found that knowledge acquisition has a positive influence on knowledge sharing, which in turn is positively reflected in its application, which positively impacts innovation in performance in Portuguese plastic injection mold making companies-these results are in line with similar studies carried out in different contexts. Consequently, knowledge, considered as an intangible asset, must be managed effectively and efficiently, in order to create value through innovation, a determinant of competitiveness in an activity sector that creates customized solutions for its customers. Despite of the small sample size, these results highlight the importance of effectively managing the acquisition.