284 research outputs found

    Behaviour and Social Skills in Children Aged 3-5: Relationship with Sensory Processing

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    Children with difficulties in sensory regulation show challenges in many areas, including externalized and internalized beahiour problemsinfo:eu-repo/semantics/publishedVersio

    Incorporation of proteins and enzymes at different stages of the preparation of calcium phosphate coatings on a degradable substrate by a biomimetic methodology

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    In this work, the possibility of incorporating proteins into calcium phosphate (Ca-P) coatings, prepared on the surface of starch polymeric biomaterials by means of a biomimetic route, was investigated. The morphology, chemical composition and crystallinity of Ca-P coatings was assessed and related to the incorporation of the studied biomolecules. For that, bovine serum albumin (BSA) and aamylase were added in concentrations of 1 mg/ml to simulated body fluid (SBF) solutions, being both added at the nucleation or growth stages of the biomimetic coating process. A biodegradable blend of corn starch/ethylene vinyl alcohol (SEVA-C) was used as substrate and bioactive glass (45S5 BioglassR) was used as the nucleating agent. The obtained Ca-P coatings were characterised by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy using an attenuated reflectance device (FTIR-ATR) and thin-film X-ray diffraction (TF-XRD). Additionally, to evaluate the activity of the incorporated enzyme and the stability of the Ca-P films, coated samples were immersed in an SBF solution for different periods of time. The enzyme activity was measured and the morphology of the coating examined by SEM. The results obtained showed that the presence of protein molecules, at the nucleation or growth stages, lead to the formation of a dense Ca-P film presenting different morphologies that were different of the selected coating conditions. FTIR-ATR analysis detected the presence of carbonate and phosphate groups on the Ca-P layer, indicating the formation of a coating similar to the mineral component of vertebrates bone tissue. When proteins were added, amide I and amide II bands, characteristic groups of protein molecules, were also detected, revealing the efficient incorporation of these biomolecules into the Ca-P coatings. Ca-P coatings, with a-amylase incorporated at the nucleation stage, showed no degradation of the film after incubation in SBF for 28 days. The release of increasing concentration of reducing sugars with degradation time revealed that a-amylase was efficiently incorporated in the coating remaining active throughout the coating preparation. This can be a strategy that will allow, in addition of conferring osteoconductive properties to biodegradable polymers, also simultaneously tailoring their degradation kinetics.Fundação para a Ciência e a Tecnologia (FCT

    Highly porous and interconnected starch-based scaffolds : production, characterization and surface modification

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    A convenient and straightforward process for preparation of highly porous and interconnected !ber mesh scaffolds with 50 wt.% content of starch is described. The proposed methodology avoids some of the previous encountered problems associated with the processing of starch-based materials such as thermal degradation, starch entrapment in the material bulk and inability to control/minimise the thickness of the !bers obtained by melt spinning, or low porosity and lack of interconnectivity for the scaffolds obtained by extrusion or injection moulding with blowing agent. Topographical characterisation of the obtained !bers revealed rough surface commonly related with increased cell attachment and growth. The in vitro tests with osteoblast cell line con!rmed this trend and we observed higher cell number with increasing of the culture time. These results were also associated with protein adsorption from a complex solution where predominant adsorption of vitronectin over !bronectin was detected. Finally, a model modi!cation by plasma was also carried out in order to con!rm the versatility of these scaffolds by the possibility to further upgrade them via surface functionalisation. The in vitro tests con!rmed that osteoblast-like cells proliferate faster on the modi!ed scaffolds, which allows shortening the time needed for culturing prior to implantation.This work was partially supported by the European NoE EXPER-TISSUES (NMP3-CT-2004-500283), EU Marie Curie Actions, Alea Jacta Est (MEST-CT-2004-008104) and FCT project PTDC/CTM/67560/2006. The authors would also like to acknowledge Sofia G. Caridade and Dr Marina I. Santos for their excellent technical assistance with the DMA and confocal microscopy, respectively

    Effects of protein incorporation on calcium phosphate coating

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    The incorporation of proteins into calcium phosphate (Ca–P) coatings is expected to alter their properties. The aim of this work is, therefore, to study the effect of protein concentration on the formation of Ca–P film. A biodegradable blend of corn starch/ethylene vinyl alcohol (SEVA-C) was used as substrate and bioactive glass (45S5 Bioglass®) was used as a nucleating agent. Bovine serum albumin (BSA) and α-amylase were added, separately, at a concentration of 0.5, 1, and 5 mg/mLto simulated body fluid (SBF) solutions, at the nucleation stage. The incorporation of protein molecules was shown to affect the properties of Ca–P coatings in terms of morphology, composition and crystallinity. Both proteins seem to inhibit in some extent and/or retard the growth of Ca–P nuclei at 0.5 and 5 mg/mL concentrations. FTIR analyses revealed the presence of phosphate and carbonate groups, confiming the formation of a Ca–P layer. The characteristic groups of protein molecules were also detected on the IR spectra, which indicate the efficient incorporation of the proteins into the coatings. When α-amylase was added to the SBF solution the production of reducing sugars was detected, proving the retention of enzyme activity. These results suggest the carrier potential of Ca–P coatings for the sustained delivery of other biologically active proteins and consequently with a strong potential for inducing bone tissue regeneration.This work was partially supported by Portuguese Foundation for Science and Technology (FCT) and was performed within the framework of the project BIOLEARN (POCTI/CTM/38803/2001) through funds from the POCH and/or FEDER Programmes. 1. B. Leonor thanks FCT for providing her a PhD scholarship (SFRH/BD/9031/2002)

    Análise comparativa do "Evaluation on Ayres Sensory Integration" versus "Sensory Integration and Praxis Test"

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    Dr. Ayres desenvolveu um método válido e confiável de avaliar as funções de integração sensorial - a Sensory Integration and Praxis Test. Contudo há a necessidade de um teste que seja de mais fácil acesso a terapeutas. Assim este projeto surgiu da necessidade de existir instrumentos de avaliação validados para a população infantil. Pretende-se, deste modo, verificar se existe correlação entre os testes táteis que constituem o Teste “Evaluation in Ayres Sensory Integration” (EASI) e os testes táteis que constituem a Sensory Integration and Praxis Test. O plano é recolher dados normativos de crianças entre os 3 e os 12 anos sem necessidades ou problemáticas identificadas, aplicando 3 sub- testes táteis da SIPT (Localização do estimulo táctil, grafestesia e Identificação do dedo) e 2 subtestes táteis da EASI –Perceção Tátil: Localização e Perceção Táctil: Desenho. A comparação do desempenho nos testes tácteis da EASI (PT:L e PT:D) e os testes táteis (LTS, GRA, FI) da SIPT, surge da necessidade de perceber se os testes tácteis da EASI podem ser utilizados para fornecer informação válida e confiável para avaliar funções da perceção táctil, na integração sensorial, que fundamentem a aprendizagem, comportamento e participação da criança. Este estudo poderá dar indicação se os testes da EASI, conseguem resultados tão fidedignos como os do SIPT, e podem ser usados pelos profissionais de forma a que as influências ou cultura, compreensão da linguagem e experiência prévia sejam minimizados.info:eu-repo/semantics/publishedVersio

    Designing biomaterials based on biomineralization of bone

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    In nature, organisms control crystal nucleation and growth using organic interfaces as templates. Scientists, in the last decades, have tried to learn from nature how to design biomimetic biomaterials inspired by the hierarchical complex structure of bone and other natural mineralised tissues or to control the biomineralization process onto biomaterials substrates to promote the osteoconductive properties of implantable devices. The design of synthetic bone analogues, i.e., with a structure and properties similar to bone, would certainly constitute a major breakthrough in bone tissue engineering. Moreover, many strategies have been proposed in the literature to develop bioactive bone-like materials, for instance using bioactive glasses. Fundamental aspects of biomineralization may be also important in order to propose new methodologies to improve calcification onto the surface of biomaterials or to develop bioactive tridimensional templates that could be used in regenerative medicine. In particular, it has been shown that some chemical groups and proteins, as well as the tridimensional matrix in which calcification would occur, play a fundamental role on the nucleation and growth of hydroxyapatite. All these distinct aspects will be reviewed and discussed in this paper.I. B. Leonor thanks the Portuguese Foundation for Science and Technology (FCT) for providing her a post-doctoral scholarship (SFRH/BPD/26648/2006). This work was supported by the European NoE EXPERTISSUES (NMP3-CT-2004-500283) and by the Portuguese Foundation for Science and Technology, FCT, through the projects PTDC/CTM/68804/2006, PTDC/CTM/67560/2006 and PTDC/FIS/68209/2006

    Natural origin scaffolds with in situ pore forming capability for bone tissue engineering applications

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    This work describes the development of a biodegradable matrix, based on chitosan and starch, with the ability to form a porous structure in situ due to the attack by specific enzymes present in the human body (a-amylase and lysozyme). Scaffolds with three different compositions were developed: chitosan (C100) and chitosan/starch (CS80-20, CS60-40). Compressive test results showed that these materials exhibit very promising mechanical properties, namely a high modulus in both the dry and wet states. The compressive modulus in the dry state for C100 was 580 ± 33 MPa, CS80-20 (402 ± 62 MPa) and CS60-40 (337 ± 78 MPa). Degradation studies were performed using a-amylase and/or lysozyme at concentrations similar to those found in human serum, at 37 C for up to 90 days. Scanning electron micrographs showed that enzymatic degradation caused a porous structure to be formed, indicating the potential of this methodology to obtain in situ forming scaffolds. In order to evaluate the biocompatibility of the scaffolds, extracts and direct contact tests were performed. Results with the MTT test showed that the extracts of the materials were clearly non-toxic to L929 fibroblast cells. Analysis of cell adhesion and morphology of seeded osteoblastic-like cells in direct contact tests showed that at day 7 the number of cells on CS80-20 and CS60-40 was noticeably higher than that on C100, which suggests that starch containing materials may promote cell adhesion and proliferation. This combination of properties seems to be a very promising approach to obtain scaffolds with gradual in vivo pore forming capability for bone tissue engineering applications.This work was supported by the European NoE EXPERTISSUES (NMP3-CT-2004-500283), the European STREP HIPPOCRATES (NMP3-CT-2003-505758) and the Portuguese Foundation for Science and Technology (FCT) through POCTI and/or FEDER programmes

    Differences in the Prevalence of Non-Communicable Disease between Slum Dwellers and the General Population in a Large Urban Area in Brazil.

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    Residents of urban slums are at greater risk for disease than their non-slum dwelling urban counterparts. We sought to contrast the prevalences of selected non-communicable diseases (NCDs) between Brazilian adults living in a slum and the general population of the same city, by comparing the age and sex-standardized prevalences of selected NCDs from a 2010 survey in Pau da Lima, Salvador Brazil, with a 2010 national population-based telephone survey. NCD prevalences in both populations were similar for hypertension (23.6% (95% CI 20.9⁻26.4) and 22.9% (21.2⁻24.6), respectively) and for dyslipidemia (22.7% (19.8⁻25.5) and 21.5% (19.7⁻23.4)). Slum residents had higher prevalences of diabetes mellitus (10.1% (7.9⁻12.3)) and of overweight/obesity (46.5% (43.1⁻49.9)), compared to 5.2% (4.2⁻6.1) and 40.6% (38.5⁻42.8) of the general population in Salvador. Fourteen percent (14.5% (12.1⁻17.0)) of slum residents smoked cigarettes compared to 8.3% (7.1⁻9.5) of the general population in Salvador. The national telephone survey underestimated the prevalence of diabetes mellitus, overweight/obesity, and smoking in the slum population, likely in part due to differential sampling inside and outside of slums. Further research and targeted policies are needed to mitigate these inequalities, which could have significant economic and social impacts on slum residents and their communities

    Chitosan scaffolds incorporating lysozyme into CaP coatings produced by a biomimetic route : a novel concept for tissue engineering combining a self-regulated degradation system with in situ pore formation

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    This study describes an innovative self-regulated degrading material with gradual in situ pore formation ability for bone tissue engineering applications. This approach is based on the incorporation of the lysozyme enzyme into calcium phosphate (CaP) coatings, prepared on the surface of chitosan scaffolds by means of a biomimetic coating technique with the aim of controlling their degradation rate and subsequent formation of pores. However, because lysozyme has antibacterial properties, these coatings may act as a carrier for its sustained release, preventing infection upon implantation. In order to prove the concept of in situ pore formation, the coated scaffolds (with and without lysozyme) were incubated in two different solutions at different pH to simulate normal physiological conditions (pH 7.4) and inflammatory response (pH 5). The weight loss and morphology of the scaffolds was monitored over time. At pH 7.4, the scaffolds remained more stable than at pH 5. The scaffolds incubated at pH 5 showed a rapid decrease in their initial weight, and scanning electron microscopy imaging revealed the formation of a highly porous structure. Furthermore, evaluation of the activity of the incorporated lysozyme revealed that the enzyme was able to hydrolyse the peptidoglycan of the bacteria cell walls (as detected by the decrease in optical density with time), indicating that the enzyme remained active after being incorporated into the CaP coating.This work was supported by the European NoE EXPERTISSUES (NMP3-CT-2004-500283), the European STREP HIPPOCRATES (NMP3-CT-2003-505758), the Portuguese Foundation for Science and Technology (FCT) through POCTI and/or FEDER programmes

    A complementaridade de pais e de profissionais na avaliação em Intervenção Precoce

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    O estudo teve por objetivo analisar a convergência entre pais e profissionais relativamente à avaliação da área da interação social em crianças com Transtorno do Espectro Autista (TEA), entre três e seis anos, apoiadas pelo sistema de intervenção precoce em Portugal.info:eu-repo/semantics/publishedVersio
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