Rikio Tsushima

Double-Blind Controlled Study on the Effects of Dietary Diacylglycerol on Postprandial Serum and Chylomicron Triacylglycerol Responses in Healthy Humans

Objective: The effects of dietary diacylglycerol (DG) on postprandial lipemia in healthy humans were investigated. Methods: Forty normolipidemic male volunteers ingested fat emulsions containing either DG oil or triacylglycerol (TG) oil, at different doses: 10 g (n = 13), 20 g (n = 10) and 44 g (n = 17). Two test emulsions were given at seven-days intervals in random order. Fatty acid compositions of the test oils had been adjusted to be equal. Fasting and postprandial serum lipid concentrations in each group and plasma lipoprotein lipids in the 20 g-fat ingestion group were measured during the postprandial intervals. Results: When DG emulsion was ingested, serum TG concentrations were significantly lower (p < 0.05) in the late postprandial phase, i.e., 4 hours, 6 hours as compared to the TG emulsion. The magnitude of postprandial lipemia (the area bounded by the curve above the fasting concentration) after ingestion of 44 g-DG emulsion was significantly less than that of 44 g-TG emulsion (6.54 ± 5.12 and 8.45 ± 7.54 mmol · h/L, mean ± SD, respectively). Chylomicron TG, cholesterol, and phospholipid concentrations at 4 hours after ingestion of DG emulsion were significantly lower (p < 0.05) than those after the ingestion of TG emulsion at the same time point. No marked differences were observed for VLDL, LDL and HDL lipids between the test emulsions. Conclusion: In the usual range of fat intake (10–44 g), postprandial response after ingestion of DG emulsion was significantly less than that after ingestion of TG emulsion in healthy human subjects.

Electrical conductivity of drawn polythiophene films

Abstract We have investigated the electrical conductivity of drawn polythiophene films doped under various conditions. By vapour-phase iodine doping at 25 °C, a drawn film shows an increase in conductivity to a value greater than 150 S/cm, whereas an undrawn film has a conductivity of 60 S/cm. The conductivity of the drawn film increases with increasing dopant concentration and reaches the extremely large value of 1 kS/cm for a film heavily doped at higher temperature. A metal-like temperature dependence of the d.c. conductivity between 120 °C and 50 °C is observed in such a drawn and heavily-doped film.

Solvent effect on electrochemical polymerization of aromatic compounds

Abstract The effects of the electrolytic conditions on the outcome of the electrochemical polymerization of pyrrole, thiophene and benzene were investigated. The solvent nucleophilicity, represented by the donor number, was found to affect the selectivity of the film formation. These solvent effects were explained in terms of the radical cation character of the intermediate and were quite similar to that of cationic polymerization of vinyl monomers. The solvent polarity, defined by the RPM value, was related to the current density during the reaction.

Fat-soluble vitamin status is not affected by diacylglycerol consumption

Objective: The objective of this study was to examine the effect of dietary diacylglycerol (DAG) on the bioavailability of fat-soluble vitamins in comparison with triacylglycerol (TAG). Methods: We conducted a long-term administration test of DAG and TAG in 27 healthy men aged 27–47 years. After measuring baseline values, subjects were randomized into two groups, one group (n = 15) was given DAG and the other (n = 12) was given TAG. Subjects ingested 20 g of DAG or TAG either in mayonnaise or an emulsion drink of their own choice at meals once a day for 12 weeks. At 4, 8 and 12 weeks, fasting blood samples were drawn and serum levels of vitamin A, E, and D were measured. Results: There were no significant changes in vitamin A levels throughout the study period. Compared to the initial values (using a Student’s t test for paired values), significant differences of vitamin E and D were seen at some points during the experiment. According to a two-way repeated measures analysis of variance, however, DAG and TAG (lipid) and time had no effect on fat-soluble vitamin levels. Conclusions: Our results indicate that DAG does not affect the absorption of the fat-soluble vitamins in diets.

Electrical conductivity of elongated polypyrrole film

The mechanical and electrical properties of elongated polypyrrole film have been investigated. The maximum elongation ratio of electrochemically prepared polypyrrole film increased on decreasing the elongation speed and reached 0.55. The simultaneous measurement of tensile stress and electrical resistance of the film during elongation has also been carried out. The approximately constant resistivity of the film by weight or volume was observed during measurement at slow elongation speeds; this provides evidence that the polypyrrole is a low-dimensional conductor. The electrical conductivity of the elongated and relaxed films increased in proportion to the square of the elongation ratio. The films with an elongation ratio of over 0.25 exhibited anisotropy in the conductivity.

Preparation of Bacterial Adsorption Polymer and Its Application to Biosensors

Polymer particles immobilizing poly(N-benzyl-4-vinylpyridinium bromide) on their surfaces were prepared via reaction of a base polymer containing chloromethyl groups with poly(vinylpyridine), followed by quaternization with benzyl bromide. The polymer particles exhibited high adsorptive activity for microorganisms. A BOD sensor was prepared by a combination of a column packed with the polymer particles carrying activated sludge with an oxygen electrode. BOD values obtained using the BOD sensor agreed with those determined by the standard method.