Transport properties, transmembrane

The porous properties of mesoporous layers can be characterized conveniently using classical methods based on the N > adsorption-desorption isotherm at 77 K. However, it is important to use additional techniques based on transmembrane transport properties in order to characterize the passing-through pores. Moreover, these dynamic methods will easily detect the... 

Transport properties have been studied before and after Si deposition using a rig similar to the one for catalytic testings (Figure 2). Pure gas permeabilities (H2, He, N2, normal and isobutane) were studied by measuring the flux passing though the membrane as a function of temperature and pressure for a constant transmembrane differential pressure (no sweep gas). 

The non-specific alkaline phosphatases present in bone and calcifying cartilage have several properties in common. The ATPases concerned in the formation of different hard tissues seem to be isozymes. It could be shown that two enzymes capable of degrading ATP exist. One of them can be inhibited by levamisole and R 8231 and is probably identical with non-specific alkaline phosphates. The activity of the other enzyme, tentatively named Ca-ATPase , is dependent on the presence of Ca2+ or Mg2+ and is activated by these ions. The Ca-ATPase is unaffected by ouabain and ruthenium red. It may be speculated that the Ca-ATPase is concerned with the transmembranous transport of Ca2+-ions to the mineralization front229. ... 

Thus molecules which assume a compact conformation will have a lower molecular volume and thus a higher diffusivity. An important consequence of this property is that even if such molecules have a high molecular weight (i.e. above the molecular weight threshold of 500 Da normally the cut-off limit for transmembrane transport), their high diffusivity may nevertheless be able to facilitate absorption. 

The next important property of PolyP-PHB complexes is their effect on DNA transfer into bacterial cells. It was the striking correlation between PolyP-PHB concentrations and transformation efficiencies in Azotobacter vinelandii, Bacillus subtilis and E. coli that led Reusch and Sadoff (1988) to postulate that the complexes are involved in DNA transmembrane transport. 

Then, a comparison of complex formation constants which are tackled in the colloquial manner affords a numerical value which corresponds to an average fractionation capacity of that mixture or biomass sample with respect to metal ions. Yet the scope is broader toxicity issues in comparison of various heavy metals or other biochemical properties such as biocatalytic efficiency can be addressed in the same way as simple accumulation or fractionation (including the fact that fractionation may be amplified relative to differences of complex stabihties by multiple speciation events or by transmembrane transports). 

Transport Properties. Important transmembrane transport parameters of the fibers are Lp, the hydraulic conductivity Pm, the diffusive permeability for a given solute o, the solute reflection coefficient and R, the solute rejection. These coefficients appear in the following equations, which are assumed to be valid at the steady state at each position Z along the fiber wall ... 

PIMs share many characteristics with polymer ion-selective electrode (ISE) membranes which have been known for many years and are often referred to as plasticized membranes (Nghiem et al, 2006). PIMs are designed for fast transport of the target chemical species across the membrane. They often completely extract a particular species from a solution, as is common with separation techniques for hydrometallurgical or remedial environmental applications (Cox, 2004 Lo et al, 1983). These properties of PIMs are in sharp contrast with those of the plasticized membranes used in ISEs where the transmembrane transport is negligible. 

Previously the possibility of using Sc, Sm, and Nd mono- and diphosphorylated amines 1-3 as membrane carriers in conditions of active transport with use of 1,2-dichlorobenzene as a membrane solvent has been shown. At the same time, a high rate of transmembrane transfer of ions Sc and Nd N,N-bis(dihexyl phosphoryl methyl) octyl amine (1) was set. In this paper, the new results of research of membrane transport properties of 1-3 carriers, by symport mechanism are described, and in this case the environmentally acceptable solvent—kerosene as a membrane phase was used. Besides that the membrane-transport properties of diphosphorilamine 4, that have not been described previously containing simultaneously highly lipophilic methyl dioctyl phosphorylic and practically hydrophilic 0,0-diethyl ethyl phosphonate groups in a molecule was studied. It is well-known that creation of optimal hydrophilic-lipophilic balance is a precondition of transmembrane transport effectiveness with organophosphorous carriers. ... 

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