Studies on syntheses and permeabilities of special polymer membranes. XLVII. Active transport and selective transport of metal ions through membranes from poly(isobutylene-alternative co-maleic anhydride) and poly(vinyl alcohol)

When a cation exchange membrane having carboxyl groups, made of poly(isobutylene-alternative co-maleic anhydride) and poly(vinyl alcohol), was set in a diaphragm type cell, in which one side of the solution was adjusted to be acidic and the other side alkaline, metal ions were actively transported from the alkaline side to the acidic side across the membrane against the concentration gradient of metal ions between both sides. The driving force of the transport of metal ions was the difference in H⁺ ion concentration between both sides. It was presumed that the active transport was carried out chemically and physically. In the selective transport of metal ions, the selectivity was dependent on both the hydrated ionic radius for the metal ions and the affinity between the carrier fixed to the membrane, the carboxyl group, and the metal ions.     

Characteristics of permeation and separation for propanol isomers through poly(vinyl alcohol) membranes containing cyclodextrin

Poly(vinyl alcohol) membranes containing cyclodextrin (CD–PVA membrane) were prepared and characteristics of permeation and separation for propanol (PrOH) isomers through the CD–PVA membranes were investigated by pervaporation and evapomeation. Evapomeation was more effective for the separation of PrOH isomers through the CD–PVA membrane than was pervaporation. The CD–PVA membrane more preferentially permeated n-PrOH than i-PrOH from their mixtures. In particular, the mixture of 10 wt % n-PrOH concentration was concentrated to about 45 wt % through the CD–PVA membrane. Both permeability and selectivity for n-PrOH were improved with an increase of CD content in the membrane. The results were supported by the fact that the affinity of CD for n-PrOH was stronger than that for i-PrOH. The permeation mechanism of PrOH isomers through the CD–PVA membrane is discussed based on the solution–diffusion theory. © 1994 John Wiley & Sons, Inc.     

Chitosan-hybridized acrylic resins prepared in emulsion polymerizations and their application as interior finishing coatings

Chitosan was used to introduce formaldehyde adsorption abilities into an emulsion binder for interior finishing coatings. Chitosan-hybridized acrylic emulisions were prepared by two methods. To produce stable chitosan-hybridized acrylic emulsions, the pre-emulsion dropping method is superior to the monomer dropping method. The adsorption performances for fonnaldehyde in chitosan-hybridized acrylic resin films increased with increasing chitosan contents; the films also had adsorption abilities for hydrogen sulfide and ammonia. Tensile strengths and elongation at breaking points decreased with increasing chitosan contents. Interior finishing coatings made from chitosan-hybridized acrylic resin emulsions have the qualities necessary for an interior finishing coating and showed excellent adsorption abilities for formaldehyde.     

Cavernous lymphangioma of mediastinum--a case report

A 2-year-old girl with mediastinal cavernous lymphangioma was successfully treated in 1991. She had a cough and an abnormal shadow in the right mediastinum was shown on her chest X-ray. The tumor, which spread from the right upper mediastinum to the pre-aorta, was demonstrated on CT and MRI. On August 8, 1991, the operation was performed through the right thoracotomy. The tumor was located in the right-upper and middle mediastinum and involved N. phrenics and vagus, but didn't invade and was completely resected. It was 4.2 x 3.4 x 3.2 cm in size and the cut surface of the tumor had an appearance consisting of the soft solid tissue, but containing partial cystic spaces. Histological diagnosis was cavernous lymphangioma. The mediastinal cavernous lymphangioma has been reported in only 6 cases in the Japanese medical literature.     

Studies on syntheses and permeabilities of special polymer membranes. 62. Active transport of alkali metal ions through poly(vinyl alcohol) membranes crosslinked with glutaraldehyde

The transport of alkali metal ion through poly(vinyl alcohol) crosslinked with glutaraldehyde without dissociating groups in a diaphragm cell, at one side being an alkaline and at the other an acidic solution, was investigated under various conditions. The active transport fraction of alkali metal ions from the alkaline side to the acidic side was significantly influenced by the degree of crosslinking of the membrane, size of anion species, initial pH on the acidic side, and the electric potential difference across the membrane.     

Studies on syntheses and permeabilities of special polymer membranes, 36. Permeabilities of alcohols through poly(γ-alkyl l-glutamate) membranes

To reveal the permeation mechanism of liquids through polypeptide membranes, the permeation of n-alcohols through poly(γ-alkyl L-glutamate) membranes such as the polymers of methyl, ethyl, and benzyl glutamates was investigated by changing the operating temperature. It was found that there was a significant interaction between the ester groups of the side chain of poly(γ-alkyl L-glutamate) and the alcohol molecule. This interaction affected significantly the permeation rates of alcohols and the separation characteristics of alcohol mixtures.     

Studies on syntheses and permeabilities of special polymer membranes: 41. Finger-like cavities in cellulose nitrate membranes from binary organic solvents

The formation of finger-like cavities in asymmetric cellulose nitrate membranes was investigated by changing the composition of binary mixed casting solvent and the evaporation period during the membrane formation process. The nature of the casting mixture, during the solvent evaporation process, was of coacervated droplets with absorbed water molecules from the atmosphere. Changes in the concentration of cellulose nitrate and the dissolution state of the cellulose nitrate molecules in the evaporation loss of the casting solvent, were clearly related to the formation of the finger-like cavity in the back sponge layer in asymmetric cellulose nitrate membranes.     

Septic thrombosis of the portal vein due to peripancreatic ligamental abscess

Nitro reduction is a critical step in the mutagenic activation of nitroarene. Nitroarene and quinone are known to be reduced by common enzymes, and thus, naphthoquinone (NQ) was studied for its effects on the mutagenicity of nitroarene in the Ames test using Salmonella typhimurium TA98 without S9. The mutagenicity of 1,3-dinitropyrene in TA98 was found to increase 9- and 6-fold as much in the presence of 70 nmol/plate of 2-methyl-1,4-NQ and 2-hydroxy-1,4-NQ, respectively. Mutagenicity also became greater in 1,3,5-trinitronaphthalene, 1-nitropyrene and 3-nitrofluoranthene. Seventy nmol/plate of 2-methyl-1,4-NQ increased the mutagenicity of 1-nitropyrene by 10.5-fold as much.     

Valence band structure of rubrene single crystals in contact with an organic gate dielectric

Organic field effect transistors (OFETs) using crystalline organic semiconductors are of great interest because of their well-defined structural and electronic properties to study the intrinsic charge carrier transport mechanisms in π-conjugated molecular solids, as well as to unravel their potential to be applied as a novel type of electronic device. In the present study, the valence band structure of the channel region of an OFET is proposed based on photoemission results of a well-defined interface between a dielectric molecular monolayer and single crystals of 5,6,11,12-tetraphenyltetracene (rubrene) which is known to exhibit the highest field effect mobility of all organic semiconductors at room temperature. Commensurate growth of clusters of tetratetracontane (TTC; n-C₄₄H₉₀) on the rubrene single crystal surface and their morphological transformation into a uniform overlayer were observed by atomic force microscopy. Photoelectron spectroscopy measurements at various electron take-off angles were then conducted to derive the valance band width of the rubrene single crystal covered by the TTC overlayers. The valence band width at this hetero-interface was found to be equivalent to that of the pristine rubrene, which suggests an unchanged ‘band effective mass ?²(d²E/dk_||²)’ of accumulated holes even at the vicinity of hydrocarbon-based gate dielectrics.