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Abstract: Considering that there is a shortage of organ donor, the aim of tissue engineering is to develop substitutes for the replacement of wounded or diseased tissues. Autologous tissue is evidently a preferable transplant material for long-term graft persistence because of the unavoidable rejection reaction occuring against allogeneic transplant. For the production of such substitutes, it is essential to control the culture conditions for post-natal human stem cells. Furthermore, histological organization and functionality of reconstructed tissues must approach those of native organs. For self-renewing tissues such as skin and cornea, tissue engineering strategies must include the preservation of stem cells during the in vitro process as well as after grafting to ensure the long-term regeneration of the transplants. We described a tissue engineering method named the self-assembly approach allowing the production of autologous living organs from human cells without any exogenous biomaterial. This approach is based on the capacity of mesenchymal cells to create in vitro their own extracellular matrix and then reform a tissue. Thereafter, various techniques allow the reorganization of such tissues in more complex organ such as valve leaflets, blood vessels, skin or cornea. These tissues offer the hope of new alternatives for organ transplantation in the future. In this review, the importance of preserving stem cells during in vitro expansion and controlling cell differentiation as well as tissue organization to ensure quality and functionality of tissue-engineered organs will be discussed, while focusing on skin and cornea. [Copyright &y& Elsevier]

A mathematical procedure is proposed to calculate fraction solid in the solidification interval of a binary alloy using cooling curves obtained with a power compensated Differential Scanning Calorimeter (DSC). The procedure takes advantage of using a validated thermodynamic model to enhance the accuracy of fraction solid evaluations, since the enthalpy of the phases vary according to their solute mass concentrations and temperature. Solute mass concentrations are deduced from the Brody-Flemings relationship to take into account the effect of solute diffusion kinetics occurring during the solidification. The procedure is applied to the fraction solid determination of aluminum-4.5% copper alloy submitted to different cooling rates. It was found that the fraction liquid remaining just before eutectic solidification was 2.45, 2.92 and 3.66 w% for a cooling rate respectively equal to 5, 10 and 60 K/min. The back diffusion parameter defined in the Brody-Flemings relationship was found to diminish as the cooling rate increases, as this is expected from basic kinetics consideration. [Copyright &y& Elsevier]

For paramedics, loading a stretcher into an ambulance is an activity with a high risk of back injury and accidents. The objective of this study was to document strategies paramedics use at work while loading a powered stretcher into an ambulance. A total of 249 stretcher loading operations performed by 58 paramedics, and 51 semistructured post-intervention interviews were analyzed. Almost three quarters of loading operations required additional actions (e.g., raising the shoulders and additional lifting) to insert the stretcher into the cot fastener system in the ambulance. Some strategies that were necessary to complete the stretcher loading operation seemed to have negative impacts on the workers' health, such as repositioning the stretcher. This action wastes time and requires significant physical efforts, as it is usually done alone. This study suggests some potential solutions, related to equipment, training, workers and work organization, to reduce the risk of injury while loading stretchers. [ABSTRACT FROM AUTHOR]