Micelles of fluorocarbon surfactants have peculiar physicochemical characteristics compared with those of the hydrocarbon counterparts. High efficiency and novel selectivity were attainable in the catalytic hydrolysis of phenyl esters by making use of the limited miscibility of fluorocarbon with hydrocarbon.
Single-, double-, and triple-chain fluorocarbon amphiphiles with cationic or anionic head groups were prepared, and they formed clear aqueous dispersions upon sonication. Electron microscopy indicated the formation of bilayer structures (vesicle or lamella), similar to those of the hydrocarbon counterparts. DSC and fluorescence depolarization experiments established the presence of crystal-liquid crystal phase transition at temperatures higher than those of the hydrocarbon bilayers. The microenvironment of the fluorocarbon bilayer was apparently more viscous than those of hydrocarbon bilayers.
Fluorocarbon bilayer vesicles were able to trap various water-soluble substrates such as riboflavin and possessed enhanced barrier capabilities against permeation of ions and organic, compounds. Phase-separated bilayer membranes, which were formed by mixing of fluorocarbon and hydrocarbon bilayers, were remarkably effective for the control of permeation and reaction characteristics.

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It has been revealed that various fatty acids inhibit platelet functions. Their inhibitory mechanisms were reviewed mainly in the aspect of their alterations of physico-chemical properties of platelet membrane. Among the acids, long-chain cis-unsaturated fatty acids such as linoleic acid increased fluidity of platelet membrane in the concentration ranges where they inhibited aggregation. Their inhibitory effects seem to be at least partly due to their effects in causing membrane perturbation not only in vitro but also in vivo. The relation between membrane fluidity and platelet functions was also discussed.
Like unsaturated fatty acids, saturated fatty acids also inhibited platelet aggregation in vitro. They affected maximum aggregation rather than aggregation rate. Their inhibitory effects increased with increase of their alkyl chain length up to C₁₄, whereas from C₁₆ the inhibitory effects tended to decrease with increase of chain length, and stearic acid was not inhibitory. The relation between change in the membrane surface charge by these acids and their inhibitory effects on aggregation was discussed.

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The sodium pump consists of two processes which are ATP hydrolysis and the ion-translocation across the cell membrane. There are still some questions regarding the mechanism of the coupling between the two processes, though the mechanism of Na⁺, K⁺-ATPase has been fairly well established. In 1972 Post et al. suggested that K⁺ ions or K⁺-congeners were occluded in Na⁺, K⁺-ATPase. Recently, direct evidences for the existence of occluded-ion forms of the enzyme were obtained from measurements of the off-rate of Rb⁺ ion or Na⁺ ion from the enzyme. As the occluded-ion forms appear to be intermediates in the process of the ion-translocation, studies on the ion-occlusions might be important to understand the coupling of the processes mentioned above. The K⁺-occlusion and Na⁺-occlusion were reviewed as well as some general properties of Na⁺, K⁺-ATPase.

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D-and L-Phenylglycine were transported through a polymer-supported liquid membrane (an immobilized liquid membrane) which consisted of o-nitrophenyl phenylether containing chiral crown ethers. The enantiomer selectivity of as high as 9.5 was obtained when the crown ether (R) -3 was used.

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Water-soluble Estracyt^® and water-insoluble estradiol-17βwere charged into a pig ureter which was used as a device for drug delivery system. The devices containing drugs were implanted subcutaneously in the back of male Wistar rats for 8 weeks at maximum and the release profiles of drugs from the device were checked in both the in vitro and in vivo experiments. The daily doses of drugs released in vitro from the device were kept constant at rates of 0.054mg/day for Estracyt^® and 0.029mg/day for estradiol-17β. However, the daily doses of drugs released in vivo from the same device significantly decreased with an increase in implantation period. This can be easily explained from the results described below. E. g., the cumulative amounts of Estracyt^® released in vitro and in vivo from the device for a period of 4 week from start of the test were found to be 1.513 and 0.399mg, respectively, while those amounts released during the first 8 weeks period were to be 3.240 and 0.448mg, respectively, in the above order. In order to claer the cause of such a retardation of in vivo release, the mutual interaction between the rat tissue and the device was microscopically investigated.

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Reverse osmotic concentration of aqueous N, N-dimethylacetamide solutions was carried out, using cellulose acetate asymmetric membranes and composite membranes : PEC-1000, NS-100 and FT-30. Separation of N, N-dimethylacetamide and solution flux through the membranes were measured in the following ranges : concentrations, 1 to 7 wt%, operating pressures, 2.94 to 6.86MPa.
PEC-1000 membranes show the best performance among the membranes tested. Its separation was above 99.5% and the best was 99.95% at 1wt%, 7MPa. At the same experimental condition, separation of FT-30 BW was 92%, FT-30 SW 94%, NS-100 P 1700 86%, NS-100 P 3500 95%, CA heat treated at 90°C 93%, 87°C 74%, and 85°C 76%.
An analysis of data with Spiegler-Kedem's transport model was carried out to obtain membrane constants such as reflection coefficient σ, solute and hydraulic permeabilities w and L_p, and concentration induced compaction coefficients for ω and L_p, β_s and β_v, . Values of a for PEC-1000 are 1.0. FT-30 shows the largest value of β_v, and cellulose acetates are the smallest.
Energy and membrane area required using PEC-1000 were calculated to concentrate aqueous N, N-dimethylacetamide solution from 0.6wt% to 5.1wt% and 9.7wt% by reverse osmosis. The energy per kilogram of concentrated N, N-dimethylacetamide is proportional to operating pressure and slightly depends on final concentration and concentration polarization, and is found 0.25 to 0.55 kwh /kg-DMAc. The membrane area is inversely proportional to the operating pressure and found 0.52 m²/kg-DM Ac/day to concentrate upto 9.7wt%, at 5 MPa, and no concentration polarization.

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The concentration of tetraphenylphosphonium (TPP⁺) was measured under various controlled conditions with a TPP-selective electrode. Assuming that membrane potential in synaptosomes is depolarized replacement of sodium with potassium in the physiological saline, we estimated the amount of TPP bound to plasma membranes and mitochondria in synaptosomes. About 50% of TPP⁺ was bound to plasma membranes and about 45% was mitochondria in synaptosomes. Membrane potentials in synaptosomes under various conditions were calculated by the Nernst equation using these values. The resting potential of synaptosomes was estimated to be-70 to-90mV.
The propriety of these values obtained and of the method, for calculation were discussed.

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