The use of public randomization in discounted repeated games

This paper presents an example where the set of subgame-perfect equilibrium payoffs of the infinitely repeated game without public randomization is not convex, no matter how large the discount factor is. Also, the set of pure-strategy equilibrium payoffs is not monotonic with respect to the discount factor in this example. These results are in sharp contrast to the fact that the equilibrium payoff set is convex and monotonic if public randomization is available.     

Emission mechanism of radiophotoluminescence in Ag-doped phosphate glass

The objective of this study is to investigate the emission mechanism of radiophotoluminescence (RPL) in the Ag⁺-doped phosphate glass (glass dosimeter), which is now used as individual radiation dosimeter, because the emission mechanism of RPL in glass dosimeter was not fully understood. Optical properties such as optical absorption spectrum, RPL spectrum and change of RPL spectrum as a function of X-ray irradiation dose were measured for commercially available glass dosimeter. In this study, we discuss the emission mechanism of two RPL peaks at 460 nm and 560 nm, based on the fact that electrons and holes produced by X-ray irradiation are trapped at Ag⁺ ions to produce Ag⁰ and Ag²⁺ ions, respectively, when the Ag⁺-doped phosphate glass is exposed to X-ray. We would like to propose the emission mechanism of RPL peaks at 460 nm and 560 nm, concerning with Ag²⁺ and Ag⁰ ions.     

Separation properties of saccharides on a hydrophilic stationary phase having hydration layer formed zwitterionic copolymer

A novel water-holding adsorbent bonded with a zwitterionic polymer, diallylamine–maleic acid copolymer, was developed. With this adsorbent, hydrophilic solutes are partitioned by a hydration layer that forms on the zwitterions, as a main separating force. When the adsorbent was used to separate saccharides by normal-phase partition chromatography, the saccharides eluted in the order, mono-, di- and trisaccharide. The elution profile for mono- and di-saccharides was similar but not identical to that on anion exchange columns. This indicated that the adsorbent exhibited a complex retention behavior by the existence of both anion and cation exchange moieties in the functional polymer. Selecting Na⁺ as a counter-ion of the maleate moiety enhanced the retention of saccharide. When used in an high performance liquid chromatography (HPLC) system with gradient elution, the adsorbent enabled the simultaneous analysis of mono-, di- and oligosaccharides.     

Synthesis of Three‐Dimensional Butterfly Slit‐Cyclobisazaanthracenes and Hydrazinobisanthenes through One‐Step Cyclodimerization and Their Properties

New three‐dimensional (3D) π‐conjugated molecules, butterfly‐shaped slit‐cyclobisazaanthracenes, were synthesized in high yields by Ni‐mediated one‐step cyclodimerization of dibromoazaanthracenes with a dimethylacridine, phenothiazine, or acridone skeleton. The 3D slit butterfly shape was formed by folded azaanthracene skeletons. Closure of the slit via N?N bond formation afforded hydrazinobisanthenes with an embedded hydrazine structure in a bisanthene skeleton, which exhibited a 3D butterfly or a 2D plane structure depending on the type of heterocycle used. Extensive study of the stereoselective chemical reactivity of the butterfly shape, X‐ray analysis, DFT calculations, electrochemical/chemical oxidations, and photophysical measurements revealed that the properties of these materials included stereoselective oxidation, a rigid or flexible butterfly shape, dynamic conformational behavior, unique crystal‐packing structures, excellent electron donation with low oxidation potential, a radical cation, a long absorption wavelength, and fluorescence property.     

Highly regioselective cyclotrimerization of 1-perfluoroalkylenynes catalyzed by nickel.

We report the highly regioselective cyclotrimerization of the 1-perfluoroalkylenynes in the presence of Ni(PPh3)4. The substituent effects on the reactivity of the enynes were investigated. We also succeeded in the nickel-catalyzed cocyclization of the 1-perfluoroalkylenynes with (trimethylsilyl)-acetylene. The possible structures of the intermediates of the cyclotrimerization and the reasons for the observed high regioselectivity were discussed.     

Enantioselective cyclopropanation reaction using a conformationally fixed pyridinium ylide through a cation-π interaction

Using a chiral pyridinium ylide with a fixed conformation through a cation-π interaction performs enantioselective cyclopropanation of electron-deficient olefins. ¹H NMR, X-ray structural analysis and DFT calculations elucidated the self-complexation and the face-to-face arrangement between the pyridinium and the phenyl rings. The absolute configuration of the product was determined after conversion into a bicyclic cyclopropane derivative.     

Glucose oxidase-immobilized glass disks for imaging of D-glucose in acute brain slices.

A biotinylated glucose oxidase (bGOD)-immobilized glass disk was prepared for visualizing D-glucose fluxes in acute brain slices. A mouse hippocampal slice was placed on the bGOD disk and stimulated with a stimulant solution containing horseradish peroxidase (HRP) and a substrate DA-64, followed by capturing digital images of Bindschedler's Green (BG), an oxidized form of DA-64, with a CCD camera. The bGOD membranes responded proportionally to D-glucose, ranging from 2.0 to 5.0 mM. Sucrose, GABA, L-glutamic acid, L-aspartic acid, glycine, acetylcholine and L-ascorbic acid at 10 mM did not cause any responses. The D-glucose fluxes in mouse hippocampal slices stimulated by a hypoxia solution were neuronal region-dependent, i.e., dentate gyrus (DG), cornu ammonis 1 (CA1) and cornu ammonis 3 (CA3), while those stimulated by KCl was independent of the neuronal regions. The response of bGOD disks is discussed in terms of the principle, concentration dependence and selectivity.     

Kinetic resolution of d,l-1,2-diols catalyzed by amine-phosphinite bifunctional organocatalysis derived from quinidine

Racemic C₂-symmetric 1,2-diols were kinetically resolved by the acylation reaction catalyzed by the phosphinite derivative of quinidine to afford the corresponding monoacylated product with good to high enantioselectivities.