Advanced silk-based biotextiles for bone regeneration applications

Increasing efforts have been made in tissue engineering (TE) research for novel biomaterials and scaffolds that can efficiently support bone tissue regeneration and repair. Textile-based technologies are predefined manufacturing processes of particular interest since they allow for producing finely tuned fiber-based structures with controlled three-dimensional architecture and improved mechanical properties. Highly reproducible scaffolds can be achieved with interconnected macro- and micro-porosity suitable for controlling cell functions and guiding bone tissue regeneration and repair. Herein, the recent studies dealing with the processing methodologies, physical properties, and biocompatibility of fiber-based scaffolds for bone TE applications are overviewed. The fundamentals and application of silk fibroin (SF) protein as biomaterial for scaffolds production, made up of micro- and nano-fibers are also considered. The promising outcomes of such investigations are summarized and discussed in depth.The authors thank to the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). The financial support from the Portuguese Foundation for Science and Technology to Fun4TE project (PTDC/EMD-EMD/31367/2017), for the Junior Researcher contract (POCI-01-0145-FEDER 031367), and for the FCT distinction attributed to J. M. Oliveira under the Investigador FCT program (IF/01285/2015) are also greatly acknowledged

Advances on gradient scaffolds for osteochondral tissue engineering

The osteochondral (OC) tissue is one of the most hierarchical and complex structures known and it is composed by two main compartments of hyaline articular cartilage and subchondral bone. It exhibits unique cellular and molecular transitions from the cartilage to the bone layers. OC diseases such as osteoarthritis and traumatic lesions may affect the articular cartilage, calcified cartilage (interface region) and subchondral bone, thus posing great regenerative challenges. Tissue engineering (TE) principles can offer novel technologies and combinatorial approaches that can better recapitulate the biological OC challenges and complexity in terms of biochemical, mechanical, structural and metabolic gradients, and ultimately can provide biofunctional 3D scaffolds with high reproducibility, versatility and adaptability to each patientâ s needs, as it occurs in OC tissue defects. The recent reports and future directions dealing with gradient scaffolds for OCTE strategies are overviewed herein. A special focus on clinical translation/regulatory approval is given.The authors thank the financial support provided by the EU-EC through the BAMOS project (H2020-MSCA-RISE-2016-734156). Viviana P Ribeiro acknowledge for the Junior Researcher contract (POCI-01-0145-FEDER-031367) attributed by the Portuguese Foundation for Science and Technology to Fun4TE project (PTDC/EMD-EMD/31367/2017)

Special issue: Biopolymer-based materials for biomedical engineering

In the field of tissue engineering and regenerative medicine (TERM), the use of traditional biomaterials capable of integrating the host tissue to promote the healing and regenerative process while it degrades has become less and less a focus of inspiration. The current trend is to increase the complexity of the host materials in order to better emulate the extracellular microenvironment of heathy and disease tissues. Thus, the combination of materials engineering with other emerging fields, such as nanotechnology, cell and molecular therapy, and precision medicine, can allow for the development of innovative biopolymer-based scaffolds for specific biomedical approaches

Post-Stroke Depression, Apathy and Alexithymia

Introdução: São diversas as alterações comportamentais decorrentes do acidente vascular cerebral (AVC). Vários estudos avaliaram a frequência e gravidade de depressão, apatia e alexitimia consequente ao AVC, sendo os resultados publicados contraditórios. Objectivo: Este artigo pretende realizar uma revisão da literatura sobre os conceitos de depressão, apatia e alexitimia e sobre os correlatos neuroanatómicos, conhecidos até à data, que suportam estes achados psicopatológicos no pós-AVC. Métodos: Revisão não sistemática da literatura através da pesquisa em referências bibliográficas consideradas relevantes pelos autores suplementada por artigos obtidos através de pesquisa na base de dados Medline/Pubmed utilizando combinações das seguintes palavras-chave: “stroke”, “apathy”, “alexithymia”, “depression”, publicados entre 1973 e 2013. Foram ainda consultadas referências bibliográficas dos artigos obtidos e livros. Resultados e Conclusões: Após o AVC, muitos doentes sofrem de défices sequelares, resultando num processo de luto, sendo que esta resposta emocional considerada consequência normativa a problemas pós-AVC. Percebeu-se que a dimensão depressiva está associada com o funcionamento do lobo frontal esquerdo (a chamada “teoria do lobo frontal esquerdo”), contudo, a dimensão apática está associada com os gânglios da base. A taxa de apatia é mais baixa em pacientes sem doença cerebrovascular prévia, sendo que a apatia ‘pura’ (sem depressão concomitante) é duas vezes mais frequente que a taxa de depressão ‘pura’ (sem apatia concomitante). Doentes apáticos têm maior frequência de quadros depressivos graves e défice cognitivo quando comparados com os pacientes não-apáticos. Os mecanismos da consciência emocional reduzida e do embotamento expressivo após o AVC da arté- ria cerebral média são mal compreendidos. Enquanto que a apatia e a adinamia podem ser explicadas pela lesão tecidular na ínsula ou nos gânglios da base, a consciência emocional reduzida pode ter origem da alteração de actividade em regiões cerebrais distantes. As alterações funcionais e estruturais no córtex cingulado anterior já foram implicadas nos mecanismos da alexitimia. Comparado com o hemisfério esquerdo, o direito parece ser superior no processamento e organização da experiência emocional. A forma adquirida de alexitimia pode suceder secundariamente às lesões que ocorrem no território da artéria cerebral média direita (ACMD) e isto torna-se significativo porque pode alterar a apresentação tradicional de um quadro depressivo. Estudos no futuro deverão examinar se estas diferenças na localização da lesão e a sua influência na recuperação funcional poderão também fazer-se reflectir nos diferentes padrões de resposta ao tratamento, separadamente ou em conjunto

The motion of two masses coupled to a massive spring

We discuss the classical motion of a spring of arbitrary mass coupled to two arbitrary massive blocks attached at its ends. A general approach to the problem is presented and some general results are obtained. Examples for which a simple elastic function can be inferred are discussed and the normal modes and normal frequencies obtained. An approximation procedure to the evaluation of the normel frequencies in the case of uniform elastic function and mass density is also discussed.Comment: Standard Latex file plus three eps figure

Bovine Blood Constituents as Fat Replacers in Ham Pâté

Some tests were carried out in this work with the aim of evaluating a partial replacement of fat in the raw batter of ham pâté by using bovine blood constituents, such as globin (GL), plasma (PL) or 1:1 globin and plasma (GP). Plasma was separated from red cells by blood centrifugation, and globin was extracted by the carboxymethylcellulose method. The salt-soluble protein content (SSP) and the binding properties including water holding capacity (WHC) and raw batter stability (RBS) were estimated. The results indicated that among the 3 treatments studied, the use of globin showed to be a little more advantageous for the quality of the raw batter of ham pâté, since its incorporation as fat replacer led to an increase in RBS but no change of SSP was observed

THE RELATIONSHIPS BETWEEN SPRINT RUN AND STRENGTH PARAMETERS IN YOUNG ATHLETES AND NON-ATHLETES

The aim of this study was to examine the relationships between the sprint run and strength tests, which measure the capability to produce force in isometric, pure concentric and stretch shortening cycle muscular actions. The seventy two subjects were assessed for six tests 60m sprint run, to evaluate the speed, and isometric leg-press, squat jump, countermovement jump, drop jump, and 5 horizontal jumps, to evaluate strength parameters. The 5 jumps, was the most important predictor of the 60m sprint time, maybe because of is cyclic and horizontal characteristics (more similar to the specific movement of sprint run). We suppose that the reason for results do not explain different relationship between tests and sprint performance, in young athletes can be find in multifactorial characteristics of sprinting performance and the characteristics of the subjects, youngest have reduced training adaptation