Synergetic transport

Cation-anion cotransport was effected by an optically active macrotricyclic cryp-tand that carried simultaneously an alkali cation and a mandelate anion and displayed weak chiroselectivity [4.23a], as did also the transport of mandelate by an optically active acyclic ammonium cation [6.39]. Employing together a cation and an anion carrier should give rise to synergetic transport with double selection by facilitating the flow of both components of a salt (see the electron-cation symport below). Selective transport of amino acids is effected by a convergent dicarboxylic acid receptor [4.24b]. 

V. Mendez et al., Reaction-Transport Systems, Springer Series in Synergetics, DOI 10.1007/978-3-642-11443-4 l, Springer-Verlag Berlin Heidelberg 2010... 

Cu-BTC (Figure 5b) or ZIF-8 (Figure 6a) and the zeolite silicalite-1 (SIC) were combined in a MMM with polysulfone Udel P-3500 for the separation of CO2/N2, CO2/CH4, O2/N2, and H2/CH4 mixtures. For some of these gas mixtures, the combined-filler MMM showed a synergetic enhancement in selective gas transport when compared either to the pure polymer or to the MMM with only one filler type. All fillers, at the same loading of 16 wt%, increase the CO2 permeability when compared to that of the bare polymer in the two C02-containing mixtures. However, the maximum separation selectivities for CO2/CH4 and CO2/N2 mixtures ( co2/ch4 = 22.4 with P = S.9 barrer for CO2, and UcOj/Nj S.O with P=SA barrer for CO2) were obtained only for Cu-BTC when combined with SIC in a PSF MMM. ... 

Under these conditions we are also able to couple the electron transport from ascorbate with spinach Fd-NADP-reductase and thus photoreduce exogenous NADP. Lower rates of NADP photoreduction by the immobilized Nostoc cells occur in the absence of MV. Probably endogenous ferredoxins are able to transfer electrons to the added enzyme. No NADP photoreduction can be observed without added reductase and very low rates are genera y measured under conditions which do not support accumulation of MV in the reaction mixture (e.g., presence of Op, or absence of glutathione whicjji is used as a synergetic reductant to limit the back reaction of MV with photoxidized ascorbate [Krasnovsky et al. 1980]. 

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