Membrane adhesion

The completed exopolysaccharide is then transported to the cell surface through membrane adhesion zones. 

Yoon el al. [112] reported an all-solid-state sensor for blood analysis. The sensor consists of a set of ion-selective membranes for the measurement of H+, K+, Na+, Ca2+, and Cl. The metal electrodes were patterned on a ceramic substrate and covered with a layer of solvent-processible polyurethane (PU) membrane. However, the pH measurement was reported to suffer severe unstable drift due to the permeation of water vapor and carbon dioxide through the membrane to the membrane-electrode interface. For conducting polymer-modified electrodes, the adhesion of conducting polymer to the membrane has been improved by introducing an adhesion layer. For example, polypyrrole (PPy) to membrane adhesion is improved by using an adhesion layer, such as Nafion [60] or a composite of PPy and Nafion [117],... 

Applied Chemislry Surface chemistry and behavior of surfactants catalysis filtration/reverse osmosis membranes adhesion surface lubrication, e.g. magnetic tape encapsulation. 

I.J. Ryrie and N. Fuad, Membrane adhesion in reconstituted proteoliposomes containing the light-harvesting chlorophyll a/b-protein complex the role of charged surface groups, Arch. Biochem. Biophys. 214 (1982) 475-488. 

Stability of sodium ISFETs. The PVC and KP-13 matrix ISFETs have some drift characteristics of a few mV per hour. The lifetimes of the both ISFETs are about 1 week. It is considered that the drift and durability is caused by the poor membrane adhesion to the ISFET device (9). The Urushi matrix ISFETs exhibited a drift <0.1 mV per hour and durability > 1 month because of the strong adhesion of the Na+ sensing membrane to the ISFET device. 

The membrane thickness reproducibility was tested over the wafer on 32 evenly distributed membranes. A mean thickness of 61.8 im (s.d. = 7.3 im) was found across the whole wafer, while a lower ( 4 im) typical standard deviation was found on more closely located membranes. Prior to measurements, the membranes are preconditioned in 0.1 M KC1. No degradation of the membrane adhesion was observed during an immersion of 2 hours in an ultrasonic bath containing 0.1 M KC1. 

In order to maintain the advantage of the microfabrication approach which is intended for a reproducible production of multiple devices, parallel development of membrane deposition technology is of importance. Using modified on-wafer membrane deposition techniques and commercially available compounds an improvement of the membrane thickness control as well as the membrane adhesion can be achieved. This has been presented here for three electrochemical sensors - an enzymatic glucose electrode, an amperometric free chlorine sensor and a potentiometric Ca + sensitive device based on a membrane modified ISFET. Unfortunately, the on-wafer membrane deposition technique could not yet be applied in the preparation of the glucose sensors for in vivo applications, since this particular application requires relatively thick enzymatic membranes, whilst the lift-off technique is usable only for the patterning of relatively thin membranes. 

Matrix, binder Matrix, membrane Matrix, membrane Matrix, membrane Matrix, membrane Adhesive/matrix Bioerodible Biodegradable Biodegradable... 

Besides the membrane materials described above, several other membrane materials have been investigated. Aminated [44,45] and carboxylated [46,47] PVC membranes were used for covalent attachment of ionophore to the matrix and showed to have improved adhesion to the gate oxide. These membranes were also used in ion-selective electrodes and showed to be ion-sensitive up to about 50 days, but had the disadvantage of being pH dependent. Membrane adhesion to the gate oxide can also be enhanced by using Urushi latex as membrane material. Urushi latex mainly consists of Urushiol which is a mixture of 3-substituted pyrocatechol derivatives... 

Spiryda LB (1998) Myelirr protein zero and membrane adhesion. J Neurosci Res 15 137—146. 

The transport of these components and their incorporation into the outer membrane are subjects of ongoing research. After the 0-polysaccharide is ligated to the lipid A-core at the periplasmic side of the inner membrane [225], LPS is somehow targeted across the periplasm to the OM. How this occurs is still not well understood [226]. Zones of adhesion or Bayer s Patches have been observed where the IM is thought to contact the OM [227], and it has been proposed that the OM components reach the OM via these membrane contact sites, without traveling through the periplasm [228]. Consistent with this model, EM shows newly synthesized LPS at regions of membrane adhesion [229]. 

Major polymer applications membranes, adhesives, elastomeric applications... 

Yuan, R., Primakoff, P., and Myles, D.G. (1997). A role for the disintegrin domain of cyritestin, a sperm surface protein belonging to the ADAM family, in mouse sperm-egg plasma membrane adhesion and fusion. J. Cell Biol. 797 105-112. 

S. Marcelja. Electrostatics of membrane adhesion. Biophysical Journal 61 1117-1121 (1992). 

Backing layer Reservoir Membrane Adhesive layer Release liner... 

Recent experimental advances have made quantitation of weak membrane adhesion possible in concentrated solutions of macromolecules. We report direct measurements of the free energy potential for adhesion of phospholipid Dilayers in solutions of two plasma proteins (fibrinogen and albumin) over a wide range of volume fraction (Q-0.1). Tne results are consistent with a thermodynamic model for adhesion based on depletion of macromolecules from the contact zone. 

Evans, E.A. Detailed mechanics of membrane-membrane adhesion and separation. 1. Continuum of molecular cross-bridges, Biophys. J., 48,175,1985. 

In order to elucidate adhesion phenomena occurring among biological cells, a number of studies on membrane adhesion using model membrane systems (such as lipid membranes as well as lipid membranes with incorporated proteins) have recently been carried out. Some of these aggregation phenomena have been analyzed from the viewpoint of the DLVO theory 2 " -" ... 

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