Chiral lithium binaphtholate aqua complex as a highly effective asymmetric catalyst for cyanohydrin synthesis

A highly enantioselective cyanohydrin synthesis with aromatic aldehydes using chiral lithium binaphtholate aqua or alcohol complexes has been developed and is a simple and inexpensive catalyst suitable for process chemistry to give gram-scale cyanohydrins successfully. Dramatic improvements in enantiomeric excess have been realized along with an interesting changeover in absolute stereochemistry of cyanohydrin product against the thoroughly "dry" catalytic systems.     

Rapid bonding of Pyrex glass microchips

A newly developed vacuum hot press system has been specially designed for the thermal bonding of glass substrates in the fabrication process of Pyrex glass microchemical chips. This system includes a vacuum chamber equipped with a high-pressure piston cylinder and carbon plate heaters. A temperature of up to 900 degrees C and a force of as much as 9800 N could be applied to the substrates in a vacuum atmosphere. The Pyrex substrates bonded with this system under different temperatures, pressures, and heating times were evaluated by tensile strength tests, by measurements of thickness, and by observations of the cross-sectional shapes of the microchannels. The optimal bonding conditions of the Pyrex glass substrates were 570 degrees C for 10 min under 4.7 N/mm(2) of applied pressure. Whereas more than 16 h is required for thermal bonding with a conventional furnace, the new system could complete the whole bonding processes within just 79 min, including heating and cooling periods. Such improvements should considerably enhance the production rate of Pyrex glass microchemical chips. Whereas flat and dust-free surfaces are required for conventional thermal bonding, especially without long and repeated heating periods, our hot press system could press a fine dust into glass substrates so that even the areas around the dust were bonded. Using this capability, we were able to successfully integrate Pt/Ti thin film electrodes into a Pyrex glass microchip.     

A clinical trial for therapeutic drug monitoring using microchip-based fluorescence polarization immunoassay

Microchip analysis is a promising method for therapeutic drug monitoring. This led us to evaluate a microchip-based fluorescence polarization immunoassay (FPIA) system for point-of-care testing on patients being treated with theophylline. The sera were collected from 20 patients being treated with theophylline. Fluorescence polarization was measured on the microchip and theophylline concentrations in serum were obtained. Regression analysis of the correlations was done between the results given by the microchip-based FPIA and the conventional cloned enzyme donor immunoassay (CEDIA), and between the results given by the microchip-based FPIA and the conventional particle-enhanced turbidimetric inhibition immunoassay (PETINIA). We successfully carried out a quantitative analysis of theophylline in serum at values near its therapeutic range in 65 s. The results obtained by the microchip-based FPIA correlated well with CEDIA and PETINIA results; the correlation coefficients (R ²) were 0.986 and 0.989, respectively. The FPIA system is a simple and rapid method for point-of-care testing of drugs in serum, and its accuracy is the same as the conventional CEDIA and PETINIA. It is essential to use real samples from patients and to confirm good correlations with conventional methods for a study on the realization of microchip.     

On the asymptotic behavior of nonoscillatory solutions of second order quasilinear ordinary differential equations

In this paper second order quasilinear ordinary differential equations are considered, and a necessary and sufficient condition for the existence of a slowly growing positive solution is established. Moreover, the precise asymptotic forms as t→∞ of slowly growing positive solutions and slowly decaying positive solutions are obtained.     

A class of plastic constitutive equations with vertex effect—IV. Applications to prediction of forming limit strains of metal sheets under nonproportional loadings

The new plastic (elastoplastic) constitutive equation with vertex effect which was proposed and developed in the previous papers is applied to prediction of the forming limit strains of metal sheets which are subjected to various nonproportional loading without unloading and to proportional loading after another proportional loading with or without unloading. It is demonstrated that the constitutive equation is very effective, that appropriately curved strain-paths give much larger limiting strains than the corresponding straight paths do, that abrupt change in stress- or strain-path very often induces a catastrophic breakage at the instant of the path-change, and that very useful secondary FLDs (forming limit diagrams) can be drawn.     

Optical probe using eccentric optics for optical coherence tomography

We propose and demonstrate an OCT optical probe using eccentric optics. This probe enabled both forward imaging and side imaging by dividing a circular scanning area into two semicircular scanning areas using an external motor to rotate the flexible tube. The outer diameter of the probe was 2.6 mm, and its rigid portion length was 10 mm. The lateral resolution was 23 μm, and the eccentric radius was 1.1 mm. The circumferential length in scanning was 6.9 mm, and the working distance was 5 mm. OCT images of 1.5 mm × 6.9 mm (in tissue, axial × circumference), including forward image and side image, were measured with the axial resolution of 19 μm in air and a frame rate of one frame per second. The epidermis, dermis, and sweat gland of in vivo human ventral finger tips were observed.     

Synthesis of chiral 3,3′-disubstituted 1,1′-binaphthyl-2,2′-disulfonic acids

A convenient synthesis of chiral 3,3′-disubstituted 1,1′-binaphthyl-2,2′-disulfonic acids (BINSA, 1) was developed. The key was directed ortho-lithiation of BINSA methyl ester 2 with n-BuLi and subsequent reaction with an electrophile. Electrophiles such as Br₂, I₂, Me₃SiOTf, and i-PrOB(Pin) reacted smoothly with 3,3′-dilithiated BINSA methyl ester, and the corresponding 3,3′-dihalo-, 3,3′-bis(trimethylsilyl)-, and 3,3′-diboryl-BINSA derivatives were obtained in yields of 21–78%. This simple synthetic method is highly attractive since the ability to prepare 3,3′-disubstituted BINOLs in advance can be useful.     

Proton conductive polyimide ionomer membranes: Effect of NH,OH, and COOH groups

A new series of sulfonated polyimide (SPI) copolymers containing NH, OH, or COOH groups were synthesized by the polycondensation of 1,4,5,8‐naphthalnetetracarboxylic dianhydride, 3,3′‐bis(sulfopropoxy)‐4,4′‐diaminobiphenyl, and 3‐(4‐aminophenyl)‐5‐(3‐aminophenyl)‐1H‐1,2,4‐triazole (SPI‐8‐m), 3,5‐bis(4‐aminophenyl)‐1H‐1,2,4‐triazole (SPI‐8‐p), 3,6‐diaminocarbazole (SPI‐9), 3,5‐diamino‐1H‐1,2,4‐triazole (SPI‐10), bis(3‐aminopropyl)‐amine (SPI‐11), 2,6‐diaminopurine (SPI‐12), 2,4‐diamino‐6‐hydroxyprymidine (SPI‐13), or 3,5‐bis(4‐aminophenoxy)benzoic acid (SPI‐14). The obtained SPIs were soluble in polar organic solvents and gave tough and flexible membranes by solution casting. The SPI membranes having NH and COOH groups showed high thermal (decomposition temperature ≈200 °C) and mechanical (maximum stress >22 MPa) stability. Introducing NH groups, especially triazole and carbazole groups, was effective in improving proton conductive properties of SPI membranes at low humidity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2846–2854, 2010