CDRsp - Capítulos de livros
Permanent URI for this collection
Browse
Recent Submissions
- IntroductionPublication . Davis, Fred J.; Mohan, Saeed D.; Ibraheem, Muaathe A.This chapter provides a basic introduction to the topics described in this book. The principles of electrospinning, in terms of the influence of an electric field on a droplet of polymer melt or solution is introduced, and a review of some of the experimental parameters, and their relationship towards the properties of the fibres produced is given. A brief summary of the types of materials that can be electrospun is included, together with methods for their characterisation. Finally, a short review of potential applications for electrospun fibres is discussed.
- The Role of Ultrasound Imaging of Musculotendinous Structures in the Elderly PopulationPublication . Carrão, Luis Miguel Costa; Santos, Rute; Espanha, Margarida; Armada-da-Silva, Paulo; Amaral, Ana; Amado, Sandra; Almeida, Henrique de Amorim; Pascoal-Faria, Paula; Veloso, AntónioUltrasound (US) is a noninvasive and real-time method that allows the evaluating muscles and tendons. The enhanced echo-intensity (EI) on ultrasonography images of skeletal muscle is believed to reflect changes in muscle quality (MQ), and these changes accompany aging. Also related to aging, and that may more severely affect women than men, is the well-known loss of skeletal muscle mass. Often associated with the accumulation of connective tissues (e.g., adipose), it affects muscle strength and MQ and causes functional impairment. This chapter demonstrates the potential use of US imaging for assessing muscle changes associated with aging and functional decline.
- Controlling Morphology Using Low Molar Mass NucleatorsPublication . Mitchell, Geoffrey; Wangsoub, Supatra; Nogales, Aurora; Davis, Fred J.; Olley, Robert H.Crystallisation is a hugely important process in physical sciences and is crucial to many areas of, for example, chemistry, physics, biochemistry, metallurgy and geology. The process is typically associated with solidification, for example in the purification of solids from a heated saturated solution familiar to all chemistry undergraduates. Crystalline solids are also often the end result of cooling liquids, or in some cases gases, but in order to form require nucleation, in the absence of nucleation supercoiling of liquids well below the melting point is possible (Cava-gna, 2009). The quality of crystals, as gauged by size and levels of order is highly variable, and may depend on factors such as material purity and the rate of cool-ing; rapid cooling may result in poor crystallisation, or even the formation of amorphous materials with no long range order. In geological systems rates of cooling may vary over many orders of magnitude, for example obsidian is a large-ly amorphous material produced when lava is rapidly cooled (Tuffen, 2003), while the gypsum crystals found in the Cueva de los Cristales in Chihuahua, Mexico can reach 10 metres in length (Figure 1) and are formed over hundreds of thousands of years. In this latter case the formation of such large spectacular structures as shown in Figure 1 can only be explained by a low nucleation rate (García-Ruiz, 2007; Van Driessche, 2011).
- 3D shape prior active contours for an automatic segmentation of a patient specific femur from a CT scanPublication . Almeida, D.; Folgado, J.; Fernandes, P.R.; Ruben, RuiThe following paper describes a novel approach to a medical image segmentation problem. The fully automated computational procedure receives as input images from CT scan exams of the human femur and returns a three dimensional representation of the bone. This patient specific iterative approach is based in 3D active contours without edges, implemented over a level set framework, on which the evolution of the contour depends on local image parameters which can easily be defined by the user but also on a priori information about the volume to segment. This joint approach will lead to an optimal solution convergence of the iterative method. The resulting point cloud can be an excellent starting point for a Finite Element mesh generation and analysis or the basis for a stereolitography for example.
- PrefacePublication . Fernandes, Paulo Rui; Bártolo, Paulo JorgeThis book is a contribution for Tissue Engineering seen as multidisciplinary field involving scientists from different backgrounds like medicine, chemistry, material science, engineering and biology with a focus on the development of mathematical methods that are quite relevant to understand cell biology and human tissues as well to model, design and fabricate optimized and smart scaffolds.
- Photocrosslinkable Materials for the Fabrication of Tissue-Engineered Constructs by StereolithographyPublication . Pereira, Rúben F.; Bártolo, Paulo J.Stereolithography is an additive technique that produces three-dimensional (3D) solid objects using a multi-layer procedure through the selective photoinitiated curing reaction of a liquid photosensitive material. Stereolithographic processes have been widely employed in Tissue Engineering for the fabrication of temporary constructs, using natural and synthetic polymers, and polymer-ceramic composites. These processes allow the fabrication of complex structures with a high accuracy and precision at physiological temperatures, incorporating cells and growth factors without significant damage or denaturation. Despite recent advances on the development of novel biomaterials and biocompatible crosslinking agents, the main limitation of these techniques are the lack number of available photocrosslinkable materials, exhibiting appropriate biocompatibility and biodegradability. This chapter gives an overview of the current state-of-art of materials and stereolithographic techniques to produce constructs for tissue regeneration, outlining challenges for future research.
- Augmented Reality and 3D Technologies: Mapping Case Studies in EducationPublication . Cardoso, Teresa; Coimbra, Teresa; Mateus, ArturLearning anywhere, anytime is becoming ever more a daily routine, due to the increasing and recent growth of information and communication technologies. In the last 5 years, their key characteristic and specifically in the use of mobile equipment and software have been their portability, mobility, and network access. The technological development, including software applications available for the implementation of three-dimensional contents, has been following this trend. Hence, it is important to know whether and how these threedimensional contents are being integrated in educational situations, namely, regarding augmented reality and mobile learning. Thus, a synthesis of Portuguese and international research works and case studies on the use of threedimensional augmented reality is chronologically presented along with the evolution of information and communication technologies. The main goal of this knowledge mapping is to contribute to the state of the art in threedimensional augmented reality technologies in education. In addition, it is aimed at framing the creation and implementation of three-dimensional content in higher education, specifically in the field of mathematics. © Springer-Verlag Berlin Heidelberg 2015.
- Recent Advances in Additive BiomanufacturingPublication . Pereira, Rúben Filipe Brás; Bartolo, PauloThe principles of tissue engineering and regenerative medicine have been used for the development of innovative medical therapies for engineering tissues and organs. These therapies involve the use of biomaterials, cells, and biologically active molecules, according to two fundamental strategies: the top-down and bottom-up approaches. Top-down approaches, which are the most commonly used, involve the implantation of porous scaffolds, with or without living cells and bioactive agents, into the defect site in the patient. In these approaches, scaffolds act as temporary templates for the seeded cells, mimicking the properties of the native extracellular matrix and providing an adequate environment for the growth of the new tissue. Scaffolds can be produced by using either conventional or additive techniques, resulting in structures with different levels of porosity, pore size, interconnectivity, and spatial distribution. Additive biomanufacturing techniques allow significantly more control over the scaffold characteristics (e.g., architecture, porosity, permeability, etc.), enabling the automatic and reproducible fabrication of scaffolds in a wide range of polymeric, ceramic, and composite materials. Some of these techniques also allow the fabrication of constructs encapsulating living cells. This chapter describes the most recent advances in the top-down approach to fabricate scaffolds for tissue regeneration, presenting the most important additive biomanufacturing techniques and processable materials. Future perspectives in the field and challenges for future research are also discussed.
- Preface of the “3rd Symposium on Integrated Computational Tools for Advanced Manufacturing”Publication . Alves, Nuno; Pascoal-Faria, Paula; Amado, Sandra
- Transferência de tecnologia e inovação: Da academia para o mercadoPublication . Malça, Cândida; Araújo, Inês; Moita, Fernando; Capitão, Moita
- «
- 1 (current)
- 2
- 3
- »