Those with a great memory will remember that I’ve been struggling (1, 2, 3) to identify adherens and tight junction proteins (i.e., cadherins and ZO-1) in bEnd3 endothelial cells.  Since I’ve recently moved over to investigate air-blood barrier co-culture models,…

This figure is a potential response to Reviewer’s 1 question about the difference between pore discovery and transmembrane resistances and Reviewer’s 2 question about membrane vs. well resistance. a.  Resistances for an ultrathin membrane with large pores.  The pore discovery…

Our collaboration with Alison Elder, et al. in the Dept. of Environmental Medicine has led us to talk about developing a co-culture model of the air-blood barrier.  This barrier is ‘located’ at the alveolar sacs in the lungs, where lung…

One of the reviewers for the diffusion based separations paper was concerned that there would be osmotic pressure which would cause convection across the membrane.  Previously we have been aware of osmosis in the DNA experiments by Paul Black and…

In an attempt to address the Nano Letters reviewer’s comment (show molecular separation, not just Au), I ran a simple experiment where I tried to pass BSA, Cyt. C, IgG, and β-galactosidase through carbonized membranes in the pressure cell. We have…

You can use any electrokinetic phenomena to determine zeta potential since they’re all related.  Here I’ve determined the zeta potential of untreated (non), plasma oxidized (ox), and silanized (asi) samples using both streaming potential measurements and electroosmotic flow rates. These…

I dug out some of my old data and found this comparison for 3x and 6x window flow rates at different voltages (minimal repeats, error bars not included): This shows that as voltage goes up, the flow rate increases for…

Last week, I calculated the Young’s modulus and residual stress of several different membranes using the pressure-displacement technique. The measurements were performed on at least three different geometries (square and rectangle) and the results were averaged. Wafer Thick. (nm) Por.…

Pnc-Si membranes have a high rate of EO pumping, but what is the best way to compare to other pumps?  The initial figure we used is an updated version of a figure found in a paper about alumina EO pumps…

Narrow pore EO theory In narrow pores that have a significant Debye length, we need to use the same corrections on surface potential in streaming potential theory that we used in electroosmosis theory (click on link above for EO theory).…