Preoperative Kidney Function linked to mortality and readmission outcomes at Day 90 and 30 in Older Emergency Surgical Patients

Grants were received from British Geriatric Society and The Renal Association to support Louis EvansPeer reviewedPublisher PD

Stress-induced alterations in parkin solubility promote parkin aggregation and compromise parkin's protective function

10.1093/hmg/ddi413Human Molecular Genetics14243885-389

Fatigue damage and crack nucleation mechanisms at intermediate strain amplitudes

Acta Metallurgica Et Materialia384595-60

Hydrodynamics of a compound drop with application to leukocyte modeling

We study the dynamics of a compound liquid drop which is comprised of an outer membrane surface, a shell layer, and a core. The deformation due to an imposed extensional flow and the subsequent recovery are investigated computationally employing a combined Eulerian-Lagrangian technique. The numerical method allows for large viscosity and capillarity differences between layers. The present study reports several findings which provide direct insight into developing a dynamic model for leukocytes. A compound drop behaves like a homogeneous, simple liquid drop if the core is sufficiently deformed and the time scale of the core, related to the combination of its viscosity and capillarity, is comparable to that of the shell layer. Disparate time scales between the core and shell layer result in a rapid initial recoil of the drop during which the shell fluid is the primary participant in the hydrodynamics, followed by a slower relaxation period during which the core and shell layer interact with each other. Consequently, the apparent viscosity of the drop depends not only on the rheological properties of the drop, but also on the flow dynamics surrounding it. The findings obtained with the three-layer compound drop model can explain several main characteristics of leukocytes reported in the literature. Furthermore, our study suggests that unless the presence and possible deformation of the nucleus are explicitly accounted for, neither Newtonian nor non-Newtonian models for leukocytes can adequately predict the hydrodynamics of leukocytes. © 1998 American Institute of Physics

Multiphase Dynamics in Arbitrary Geometries on Fixed Cartesian Grids

In this work, a mixed Eulerian-Lagrangian algorithm, calledELAFINT(Eulerian Lagrangian algorithm for interface tracking) is developed further and applied to compute flows with solid-fluid and fluid-fluid interfaces. The method is capable of handling fluid flows in the presence of both irregularly shaped solid boundaries and moving boundaries on a fixed Cartesian grid. The field equations are solved on the underlying fixed grid using a collocated variable, pressure-based formulation. The moving boundary is tracked explicitly by the Lagrangian translation of marker particles. The moving boundary passes through the grid and the immersed boundary technique is used to handle its interaction with the underlying grid. The internal solid boundaries are dealt with by using a cut-cell technique. Particular attention is directed toward conservation and consistency in the vicinity of both phase boundaries. The complex geometry feature has been tested for a variety of flow problems. The performance of the immersed boundary representation is demonstrated in the simulation of Newtonian liquid drops. The combination of the two features is then employed in the simulation of motion of drops through constricted tubes. The capabilities developed here can be useful for solving flow problems involving moving and stationary complex boundaries. © 1997 Academic Press

Continuum-kinetic model for cell adhesion and movement

A computational approach for studying the adhesion kinetics and deformation of a cell on a substrate is presented. It is shown that the cell mechanical properties and surrounding fluid dynamics affect the receptor-ligand kinetics, and that these effects need to be included in any realistic cellsurface interaction models