Diffusion through semipermeable structures arises in a wide range of processes the physical and life sciences. Examples at microscopic level from artificial membranes for reverse osmosis to lipid bilayers regulating molecular transport biological cells chemical electrical gap junctions. There are also macroscopic analogs such as animal migration heterogeneous landscapes. It has recently been sh...

?2 microglobulin (?2m) fibril has been recognized as the major factor of dialysis-related amyloidosis. elevated serum levels are thought to be the basis for tissue deposition. in order to evaluate the effect of cellulosis membrane (fb 110) and treatment duration on s?2m levels, we determined serum levels in 23 hemodialyzed patients with end-stage renal failure. s?2m levels were markedly elevate...

A novel method for flexibly implementing sample dialysis on microchips is introduced. Nanoporous polymer membranes (5-20 pm thickness) with up to 1OOO:l aspect ratio are fabricated in-situ on silica microchips via photopatterned phase-separation polymerization. These membranes enable selective diffusion of molecules smaller than a cutoff specified by the membrane pore size. Diffusion measuremen...

A system was evaluated for growing plants at reproducible levels of water stress. Beans (Phaseolus vulgaris L.) were grown in vermiculite, transferred to a semipermeable membrane system that encased the root-vermiculite mass, and then placed into nutrient solutions to which various amounts of polyethylene glycol (PEG) 20M were added to control solution water potential. The membrane (Spectrapor ...

A high activity of reactions can be confined in a model cell with a semipermeable membrane in the Schlögl model. It is interpreted as a model of primitive metabolism in a cell. We study two generalized models to understand the creation of primitive cell systems conceptually from the view point of the nonlinear-nonequilibrium physics. In the first model, a single-cell system with a highly active...

The hollow fiber bioreactor (HFBR) is a cell culturing system allowing continuous perfusion of medium. It was designed to grow microorganisms in a dynamically altering medium mimicking change in the in vivo intravascular and extravascular compartments. The cell compartment (extra capillary space) and medium compartment (intra capillary space) are connected through pores of semipermeable fiber m...