Wavy-ply sandwich with composite skins and crushable core for ductility and energy absorption

Conventional composite materials offer high specific stiffness and strength, but suffer from low failure strains and failure without warning. This work proposes a new design for sandwich structures with symmetrically-wavy composite skins and a crushable foam core, aiming to achieve large strains (due to unfolding of the skins) and energy absorption (due to crushing of the foam core) under tensile loading. The structure is designed by a combination of analytical modelling and finite element simulations, and the concept is demonstrated experimentally. When loaded under quasi-static tension, wavy-ply sandwich specimens with carbon–epoxy skins and optimised geometry exhibited an average failure strain of 8.6%, a specific energy dissipated of 9.4 kJ/kg, and ultimate strength of 1570 MPa. The scope for further developing the wavy-ply sandwich concept and potential applications requiring large deformations and energy absorption are discussed

Aloinjerto osteocondral bipolar fresco del tobillo. Revisión de la literatura y presentación del caso de un paciente joven con artrosis bilateral postraumática

OBJECTIVES: The treatment of severe post-traumatic ankle arthritis remains a challenge nowadays. Since patients suffering from this pathology are mainly young and active people, a correct reconstruction, if possible, of the articular cartilage defects of the tibiotalar joint is very important to achieve a good result. Fresh bipolar osteochondral allograft (FBOA) is a promising operative technique, as an alternative to arthrodesis and total ankle replacement, in pain relief, restoration of function and indefinite delay of arthritic disease progression. METHODS: The authors made a review of the literature and present a case report of a young 30 years-old man, with bilateral post-traumatic osteoarthritis of the ankle, treated with (FBOA). The patient was evaluated clinically and radiographically monthly. RESULTS: Pain relief and postoperative function was significantly improved reaching 94 points in the left ankle (preoperative of 40 points), and 92 points in the right ankle (preoperative 42 points) AOFAS score. CONCLUSIONS: Fresh tibiotalar allografting seems to be a good alternative to arthrodesis and prosthetic replacement, in the treatment of ankle arthropathy and big articular cartilage defects mainly in young and active patients. This procedure achieves a good pain relief, maintaining functional joint motion and decreasing the risk of adjacent joint arthritis

Cytometric analysis, genetic manipulation and antibiotic selection of the snail embryonic cell line Bge from Biomphalaria glabrata, the intermediate host of Schistosoma mansoni.

The invertebrate cell line, Bge, from embryos of the snail Biomphalaria glabrata, remains to date the only established cell line from any species of the Phylum Mollusca. Since its establishment in 1976 by Eder Hansen, few studies have focused on profiling its cytometrics, growth characteristics or sensitivity to xenobiotics. Bge cells are reputed to be challenging to propagate and maintain. Therefore, even though this cell line is a noteworthy resource, it has not been studied widely. With growing interest in functional genomics, including genetic transformation, to elucidate molecular aspects of the snail intermediate hosts responsible for transmission of schistosomiasis, and aiming to enhance the convenience of maintenance of this molluscan cell line, we deployed the xCELLigene real time approach to study Bge cells. Doubling times for three isolates of Bge, termed CB, SL and UK, were longer than for mammalian cell lines - longer than 40 h in complete Bge medium supplemented with 7% fetal bovine serum at 25 °C, ranging from ∼42 h to ∼157 h when 40,000 cells were seeded. To assess the potential of the cells for genetic transformation, antibiotic selection was explored. Bge cells were sensitive to the aminonucleoside antibiotic puromycin (from Streptomyces alboniger) from 5 μg/ml to 200 ng/ml, displaying a half maximal inhibitory concentration (IC50) of ∼1.91 μg/ml. Sensitivity to puromycin, and a relatively quick kill time (<48 h in 5 μg/ml) facilitated use of this antibiotic, together with the cognate resistance gene (puromycin N-acetyl-transferase) for selection of Bge cells transformed with the PAC gene (puroR). Bge cells transfected with a plasmid encoding puroR were partially rescued when cultured in the presence of 5 μg/ml of puromycin. These findings pave the way for the development of functional genomic tools applied to the host-parasite interaction during schistosomiasis and neglected tropical trematodiases at large

Medicamentos genéricos e padrões de prescrição: conhecimentos e opiniões de médicos e farmacêuticos

Poucos temas são tão controversos na área da saúde como a introdução de genéricos no mercado de medicamentos, contudo, estes podem desempenhar um papel fundamental na alocação eficiente de recursos financeiros na área do medicamento. Se os médicos, através da prescrição, são o factor decisivo para o aumento da quota de genéricos; os farmacêuticos enquanto dispensadores, assumem um papel preponderante na sensibilização dos utentes para a sua aceitação e adesão à terapêutica. Objectivo do estudo - Estudar os conhecimentos e opiniões de médicos e farmacêuticos sobre os medicamentos genéricos e a sua relação com a prescrição/dispensa de genéricos

Uso de forum no ensino cooperativo de programação

A utilização de Tecnologias da Informação e Comunicação no âmbito de actividades de ensino / aprendizagem, necessita de aliar, à disponibilidade efectiva dessas tecnologias, estratégias de integração nas actividades lectivas que permitam a satisfação das expectactivas dos docentes e dos alunos. Este artigo descreve a utilização de um forum numa disciplina de introdução à programação numa perspectiva de partilha de boas práticas, e discute alguns problemas e possíveis soluções

Cerenkov angle and charge reconstruction with the RICH detector of the AMS experiment

The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the International Space Station (ISS) will be equipped with a proximity focusing Ring Imaging Cerenkov (RICH) detector, for measurements of particle electric charge and velocity. In this note, two possible methods for reconstructing the Cerenkov angle and the electric charge with the RICH, are discussed. A Likelihood method for the Cerenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution of around 0.1%. The existence of a large fraction of background photons which can vary from event to event, implied a charge reconstruction method based on an overall efficiency estimation on an event-by-event basis.Comment: Proceedings submitted to RICH 2002 (Pylos-Greece