Prediction of mechanistic cutting force coefficients using ALE formulation

This paper demonstrated the use of an efficient and accurate numerical tool (i.e., FEA) in simulating the cutting process and determining both the average and instantaneous cutting force coefficients. The main advantage of this approach compared to other available methods is that it eliminates the need for experimental calibrations. In this approach, an Arbitrary Lagrangian Formulation was employed in the finite element method simulations. This formulation has been gaining more recognition in structural analysis for its combined advantages of both Lagrangian and Eulerian formulations in a single model. Based on the work of Kline et al. (ASME J Eng Ind 104:272-278, 10), the tool is discretised along the axis into segments and the cutting forces acting on the cutting edge segment are presented in terms of cutting force coefficients. Cutting force coefficients are obtained using the least squares method and cutting force predictions using evaluated coefficients are shown to match experimental results with satisfactory accuracy. © 2009 Springer-Verlag London Limited

Exosomal transfer of mitochondria from airway myeloid-derived regulatory cells to T cells

Chronic inflammation involving both innate and adaptive immune cells is implicated in the pathogenesis of asthma. Intercellular communication is essential for driving and resolving inflammatory responses in asthma. Emerging studies suggest that extracellular vesicles (EVs) including exosomes facilitate this process. In this report, we have used a range of approaches to show that EVs contain markers of mitochondria derived from donor cells which are capable of sustaining a membrane potential. Further, we propose that these participate in intercellular communication within the airways of human subjects with asthma. Bronchoalveolar lavage fluid of both healthy volunteers and asthmatics contain EVs with encapsulated mitochondria; however, the % HLA-DR+ EVs containing mitochondria and the levels of mitochondrial DNA within EVs were significantly higher in asthmatics. Furthermore, mitochondria are present in exosomes derived from the pro-inflammatory HLA-DR+ subsets of airway myeloid-derived regulatory cells (MDRCs), which are known regulators of T cell responses in asthma. Exosomes tagged with MitoTracker Green, or derived from MDRCs transduced with CellLight Mitochondrial GFP were found in recipient peripheral T cells using a co-culture system, supporting direct exosome-mediated cell-cell transfer. Importantly, exosomally transferred mitochondria co-localize with the mitochondrial network and generate reactive oxygen species within recipient T cells. These findings support a potential novel mechanism of cell-cell communication involving exosomal transfer of mitochondria and the bioenergetic and/or redox regulation of target cells. Keywords: Exosomes, Mitochondria, Asthma, Myeloid-derived, Derived Regulatory Cell