Digestibility of mannooligosaccharides obtained from thermal hydrolysis of spent coffee grounds was examined by in vitro digestion method. Mannooligosaccharides were resistant to human salivary ␣-amylase, artificial gastric juice, porcine pancreatic enzymes and rat intestinal mucous enzymes. Fermentation products of mannooligosaccharides in human large intestine were estimated by in vitro fecal incubation method. Mannooligosaccharides were fermented by human fecal bacteria and the products of fermentation were short chain fatty acids. Acetic, propionic and n-butyric acids were the main short chain fatty acids as end fermentation products. These results suggest that mannooligosaccharides are indigestible saccharides and are converted to short chain fatty acids in human large intestine. The short chain fatty acids are thought to improve the large intestinal environment. Moreover, they are absorbed and utilized by the host as an energy source.

A convenient method for the preparation of hydroperoxy and hydroxy derivatives of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is described. PC and PE obtained from rat liver were oxidized with singlet oxygen by using methylene blue as the photosensitizer, and their hydroperoxides were isolated with the aid of reverse phase liquid chromatography. The hydroxy derivatives were obtained by reducing the hydroperoxides with sodium borohydride. The results of gas chromatography mass spectrometry revealed that hydroxy fatty acid components of the hydroxy derivatives were derived from isomeric hydroperoxides of oleic acid, linoleic acid, arachidonic acid and docosahexanoic acid. Normal phase high performance liquid chromatography did not separate the hydroperoxy and hydroxy derivatives from the respective unoxidized phospholipids, although unoxidized PC and PE were separated from each other. However, the hydroperoxy and hydroxy derivatives could be distinguished from unoxidized phospholipid species on reversed phase thin layer chromatography.

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Binary systems of Ta 2 O 5 and Nb 2 O 5 are investigated as dielectric materials that allow low-temperature fabrication and are suitable for use in metal-insulator-metal ͑MIM͒ capacitors. This investigation shows that a Nb 2 O 5 film is crystallized in a hexagonal symmetry at a temperature of less than 500°C, which is more than 250°C lower than the corresponding temperature for a Ta 2 O 5 film. Using Nb 2 O 5 as a nucleation layer lowers the crystallization temperature for Ta 2 O 5 to less than 500°C. This is because hexagonal Ta 2 O 5 is stably formed on the hexagonal Nb 2 O 5 by heteroepitaxy. A Ta 2 O 5 /Nb 2 O 5 bilayer with a high dielectric constant of 50 can therefore be prepared by a 500°C fabrication process. Solid solutions of Nb 2 O 5 and Ta 2 O 5 are also investigated. The substitution of 10% Nb 2 O 5 in Ta 2 O 5 to form ͑Ta 0.9 Nb 0.1 ͒ 2 O 5 was found to decrease the temperature of crystallization from 700°C for pure Ta 2 O 5 to 550°C. The dielectric constant of the ͑Ta 0.9 Nb 0.1 ͒ 2 O 5 film is approximately 20% greater than that of the Ta 2 O 5 film. This is because the substitutional Nb 2 O 5 stabilizes the material in the hexagonal phase, which corresponds to a high dielectric constant, at lower temperatures.