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The molecular design for large photo‐induced refractive index changes in transparent visible light region was proposed and realized with norbornadiene polymers and poly(vinyl cinnamate). The patterning of pure refractive‐index contract on their transparent films was made with near‐field scanning optical microscopy (NSOM). Reversible fluorescence patterning on polymer films is also presented by using controlled energy transfer from a fluorescent pyromethene to a photochromic diarylethene.

A rapid and sensitive method for evaluation of the radical-scavenging activity, which uses ,,,῍-azobis (,-amidinopropane) dihydrochloride (AAPH) as a radical generator in combination with a luminol chemiluminescence (CL) assay, was examined. The radical-scavenging activities of various analytical-grade compounds were measured by monitoring the decrease in CL. In this method (AAPH-CL), compounds that show lower CL values have stronger radical-scavenging activity. These results were compared to those measured using +,+-diphenyl-,-picrylhydrazyl (DPPH)-colorimetry analysis. They were approximately similar in pattern (r , ῌ*.0*.-), although there were some discrepancies. The half-inhibition concentration (IC/*) values of ++ beverages were also evaluated using AAPH-CL and DPPH-high performance liquid chromatography methods. Data from the two methods showed a correlation (r , ) of *..120. We conclude that the AAPH-CL method is suitable for the evaluation of radical-scavenging activity in vitro, with the advantages that it is rapid to carry out, has good sensitivity, is not a#ected by impurities or color in the solution, and bears some similarity to cellular processes.

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L-Ascorbic acid (AsA) has numerous biological activities. It is known that AsA is unstable under neutral and alkaline conditions, degrading almost completely within several hours, whereas it is relatively stable under acidic conditions. The present study investigated the e#ect of grape seed extract (GSE), which contains proanthocyanidins, on the stability of AsA under neutral and alkaline conditions. The addition of GSE to AsA solution in -,-῎-dimethylglutaric acid-tris(hydroxymethyl)aminomethane-,-amino-,-methyl-+,--propanediol (GTA) (/* mM, pH 1.* or +*.*) bu#er significantly increased the remaining amount of AsA and the +,+-diphenyl-,-picrylhydrazyl (DPPH) radical-scavenging activity, compared with those of AsA alone. In particular, it was clarified that GSE contributed to the stability of AsA at an alkaline pH. We also investigated the e#ect of GSE on the stability of AsA under quasi-physiological conditions. It was revealed that GSE stabilized AsA in simulated intestinal juice (pH 2./) at -1ῌ. DPPH radical-scavenging activity was closely correlated with the remaining amounts of AsA. The present results, although not directly transferable to in vivo conditions, suggest that GSE may stabilize AsA under neutral and alkaline conditions and a#ect the physiological activity of AsA.