We demonstrate that there are two experimentally distinguishable steps in the fusion of phospholipid vesicles with planar bilayer membranes. In the first step, the vesicles form a stable, tightly bound pre-fusion state with the planar membrane; divalent cations (Ca++) are required for the formation of this state if the vesicular and/or planar membrane contain negatively charged lipids. In the s...

This study was conducted to examine if L-carnitine supplementation in the Tris-egg-yolk extender can improve the motility characteristics, membrane integrity, and in vitro fertilization potential after cryopreservation of ejaculated bovine spermatozoa. It was carried out on January to May 2013 at the University of Wisconsin-Madison. L-carnitine at final concentrations of 0.5, 1, 10, and 30mM we...

It has been assumed that gelatin consists of a network of an insoluble material enclosing a solution of a more soluble material. The swelling of gelatin is therefore primarily an osmotic phenomena in that the water tends to diffuse in owing to the osmotic pressure of the soluble material. This osmotic pressure is opposed by the elasticity of the insoluble constituent, and equilibrium results wh...

We develop computational methods for the simulation of osmotic swelling phenomenarelevant to microscopic vesicles containing transformable solute molecules. We introduce StochasticImmersed Boundary Methods (SIBM) that can capture osmotically driven fluid transport throughsemi-permeable elastic membranes subject to thermal fluctuations. We also develop numerical meth-ods to handl...

In a previous communication (I) it was reported that the cell walls of Streptococcus fecalis (ATCC 9790) were susceptible to digestion by lysozyme. This finding subsequently allowed the preparation of protoplasts from these organisms by treatment of whole cells with lysozyme and the use of high concentrations of sucrose as the impermeantl substance necessary for osmotic stabilization. Further i...

Brain tissue swelling is a dangerous consequence of traumatic injury and is associated with raised intracranial pressure and restricted blood flow. We consider the mechanical effects that drive swelling of brain tissue slices in an ionic solution bath, motivated by recent experimental results that showed that the volume change of tissue slices depends on the ionic concentration of the bathing s...

Using unfertilized eggs of Arbacia punctulata as natural osmometers an attempt has been made to account for the course of swelling and shrinking of these cells in anisotonic solutions by means of the laws governing osmosis and diffusion. The method employed has been to compute permeability of the cell to water, as measured by the rate of volume change per unit of cell surface per unit of osmoti...