Chiral separation of acidic drug components by open tubular electrochromatography using avidin immobilized capillaries

Avidin was immobilized covalently onto the inner surface of fused silica capillaries as a stationary phase in an open tubular capillary electrochromatography (OT-CEC) for chiral separations. The modification was attained by a combination of glutaraldehyde with both an amino-silylated fused silica surface and avidin using a Schiff base formation reaction. This method couples the advantage of high efficiency and small consumption of a chiral selector with the possibility of UV detection without limitations of protein absorption. In addition, the prepared capillary was stable for 50 days with over 100 runs. To evaluate the electrochromatographic performance of the prepared capillaries, the chiral separation of abscisic acid and arylpropionic acids were investigated. Effects of the modification condition of protein, pH of running buffer, and an organic modifier on the enantioseparation were also investigated. In addition, the avidin immobilized capillary was employed for the selective chiral analysis with an electrospray ionization mass spectrometry (ESI-MS) detection scheme.     

On the Reduced Lefschetz Module and the Centric p-Radical Subgroups II

In this paper, we give a lower bound of the p-part of the reducedEuler characteristic of the order complex of the centric p-radicalsubgroups by studying vertices of indecomposable summands ofthe reduced Lefschetz module. This bound is in fact best possiblefor at least some groups, and also provides a uniform explanationof the observed phenomenon on the reduced Euler characteristicfor some sporadic simple groups.     

Optical noise reduction by reconstructing positive and negative images from Fourier holograms in coaxial holographic storage systems

A technique for reconstructing positive and negative images from an identical intensity-modulated hologram is demonstrated theoretically and experimentally by use of a coaxial holographic storage system. Negative images are obtained by adding a phase-modulated dc component of signal beam on reading. By comparing positive and negative images, the bit error rate (BER) is improved by two orders of magnitude. This technique can reduce optical noise of reconstructed images to attain low BERs.     

Three-dimensional motion-picture imaging of dynamic object by parallel-phase-shifting digital holographic microscopy using an inverted magnification optical system

Optical Review - We constructed a parallel-phase-shifting digital holographic microscopy (PPSDHM) system using an inverted magnification optical system, and succeeded in three-dimensional (3D)...     

Classification of companies using maximal margin ellipsoidal surfaces

We recently proposed a data mining approach for classifying companies into several groups using ellipsoidal surfaces. This problem can be formulated as a semi-definite programming problem, which can be solved within a practical amount of computation time by using a state-of-the-art semi-definite programming software. It turned out that this method performs better for this application than earlier methods based on linear and general quadratic surfaces. In this paper we will improve the performance of ellipsoidal separation by incorporating the idea of maximal margin hyperplane developed in the field of support vector machine. It will be demonstrated that the new method can very well simulate the rating of a leading rating company of Japan by using up to 18 financial attributes of 363 companies. This paper is expected to provide another evidence of the importance of ellipsoidal separation approach in credit risk analysis.     

Mechanism of high thermal stability of commercial polyesters and polyethers conjugated with bio‐based caffeic acid

In previous report, we discovered that a novel improvement technique to enhance the thermal properties of poly(L ‐lactide)s (PLLAs) by terminal conjugation with 3,4‐diacetoxycinnamic acid (DACA). In this study, we clarified the mechanism of the enhancement of thermal stability by using commercial polyesters and polyethers. The effect of thermal improvement by the terminal conjugation of DACA on poly(DL ‐lactide), poly(ε‐caprolactone), and poly(ethylene glycol) was almost the same as about 100 °C increase. The amount of residual tin catalyst, which enhances the thermal degradation of polyesters, was reduced at undetected level after the terminal conjugation of DACA probably due to the removal of tin during DACA conjugation process. Furthermore, the π‐π stacking interactions of DACA units and the chemical protection of terminal hydroxyl groups, which enhances intramolecular scission, were also important for the high thermal stability. We clarified that the extreme high thermal stability by DACA conjugation was induced by these above mechanisms. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Improvement of color rendering index of BGYR laser illuminants

Optical Review - Laser-driven phosphor conversion (PC)-type white light sources are receiving a great deal of attention in next-generation high-intensity lighting and display technologies. Laser...     

Scaling Relations for Two-Dimensional Ising Percolation

We consider the percolation problem in the high-temperature Ising model on the two-dimensional square lattice at or near critical external fields. We show that all scaling relations, except for a single hyperscaling relation, hold under the power law assumptions for the one-arm path and the four-arm paths.     

Synthesis of 2H‐Azirines by Iridium‐Catalyzed Decarboxylative Ring Contraction of Isoxazol‐5(4H)‐ones

A phosphine‐free iridium‐catalyzed reaction of isoxazol‐5(4H)‐ones (isoxazolones) has been developed, and affords 2H‐azirines through decarboxylation and ring contraction. This method provides an efficient and environmentally benign protocol which could replace the conventional approaches used to synthesize 2H‐azirines.