My introduction to membranes was as a graduate student in 1963. At that time
membrane permeation was a sub-study of materials science. What is now called
membrane technology did not exist, nor did any large industrial applications
of membranes. Since then, sales of membranes and membrane equipment have
increased more than 100-fold and several tens of millions of square meters of
membrane are produced each year—a membrane industry has been created.
The cloned guinea-pig Y2 neuropeptide Y (NPY) receptors expressed in Chinese hamster ovary (CHO) cells, as well as the Y2 receptors natively expressed in rat forebrain, are distributed in two populations. A smaller population that is readily accessed by agonist peptides on the surface of intact cells constitutes less than 30% of Y2 receptors detected in particulates after cell homogenization. A much larger fraction of cell surface Y2 sites can be activated by sulfhydryl modiﬁers.
The drug concentration inside multidrug-resistant cells is the outcome of
competition between the active export of drugs by drug efflux pumps, such
as P-glycoprotein (Pgp), and the passive permeation of drugs across the
plasma membrane. Thus, reversal of multidrug resistance (MDR) can occur
either by inhibition of the efflux pumps or by acceleration of the drug per-meation.
The high water permeability of certain biological membranes is
due to the presence of aquaporin water channel proteins. AQP1
was discovered in human red cells. AQP1 has been thoroughly
characterized biophysically, and the atomic structure of AQP1
has been elucidated. Ten homologs have been identified in
humans. These are selectively permeated by water (aquaporins)
or water plus glycerol (aquaglyceroporins). The sites of expres-sion predict the clinical phenotypes in humans. Individuals lack-ing Colton blood group antigens have mutations in the AQP1
Depth of bilayer penetration and effects on lipid mobility
conferred by themembrane-active peptidesmagainin, melit-tin, and a hydrophobic helical sequence KKA(LA)7KK
(denoted KAL), were investigated by colorimetric and
time-resolved fluorescence techniques in biomimetic phos-pholipid/poly(diacetylene)vesicles. The experiments dem-onstrated that the extent of bilayer permeation and peptide
localization within the membrane was dependent upon the
bilayer composition, and that distinct dynamic modifica-tions were induced by each peptide within the head-group
environment of the phospholipids....
Mixed ionic–electronic conductors (MIECs) have been and continue to be of interest for strategic applications related to energy conversion and environmental monitoring including batteries, fuel cells, permeation membranes, and sensors. Within solid oxide fuel cells (SOFCs), for instance, nanostructured ionic and electronic conducting materials can increase the electrochemical performance of the cathode and thus could potentially facilitate lower-temperature operation and thereby provide faster start-up times, improved stability, and less complicated thermal management. ...
Reactive liquid-liquid extraction of inorganic acids with amines and effect of solvating
diluents; Liquid extraction of tall oil from wastewaters of paper industry
• Supercritical fluid extraction of natural products; Enzymatic reactions in supercritical
CO2; Solubilities of liquids and solids in dense CO2 with entrainer
• Relation between the morphology and application properties of polymer catalysts and
• Study of the permeation and pervaporation of volatile organic substance (propan-1-ol,
• Observation of the competitive adsorption on Vycor glass membr...
Membrane separation has developed into an important technology for separating VOCs and other gaseous air pollutants from gas streams during the past 15 years. The ﬁrst commercial application was installed in 1990, and more than 50 systems have been installed in the chemical process industry worldwide.1 The technology utilizes a polymeric membrane that is more permeable to condensable organic vapors, such as C3+ hydrocarbons and aromatics, than it is to noncondensable gases such as methane, ethane, nitrogen, and hydrogen.
Diffusion is the transport of matter from one point to another by thermal
motion of atoms or molecules. It is relatively fast in gases, slow in liquids, and
very slow in solids. Diffusion plays a key rˆole in many processes as diverse as
intermixing of gases and liquids, permeation of atoms or molecules through
membranes, evaporation of liquids, drying of timber, doping silicon wafers to
make semiconductor devices, and transport of thermal neutrons in nuclear
The separation performance of plasticizer/polysulfone (TGN/PSF) pervaporation membrane was studied. The optimum
amount of plasticizer (TGN) in PSF membranes improved the diffusion selectivity of water to ethanol, which
was due to the increase in the permeate diffusion rate difference between water to ethanol molecules. On the other hand