Synthesis and evaluation of 3-methyl-4-oxo-6-phenyl-4,5,6,7-tetrahydrobenzofuran-2-carboxylic acid ethyl ester derivatives as potent antitumor agents

For the construction of new combinatorial libraries, a lead compound was created by replacing the core structure of a hit compound discovered by screening for cytotoxic agents against a tumorigenic cell line. The newly designed compound maintained biological activity and allowed alternative library construction for antitumor drugs.     

A new ring transformation of 3-halo-2-azidopyridine 1-oxides. A novel synthesis of 1,2-oxazin-6-ones

The course of the thermal ring-opening and recyclization of 2-azidopyridine 1-oxides is radically altered by the presence of a 3-halo substituent. Provided the 6-position is blocked, recyclization leads to a 6-cyano-6-halo-1,2-oxazine which hydrolyzes very readily to the 6H-1,2-oxazin-6-one. The structure of 4-bromo-3-methyl-6H-1,2-oxazin-6-one so obtained was confirmed by single crystal X-ray analysis. If the 6-position is not blocked, the product undergoes a further ring opening to give (Z)-β-cyanoacrylates.     

Measurement of temporal changes in vocal tract area function from 3D cine-MRI data

A 3D cine-MRI technique was developed based on a synchronized sampling method [Masaki et al., J. Acoust. Soc. Jpn. E 20, 375-379 (1999)] to measure the temporal changes in the vocal tract area function during a short utterance /aiueo/ in Japanese. A time series of head-neck volumes was obtained after 640 repetitions of the utterance produced by a male speaker, from which area functions were extracted frame-by-frame. A region-based analysis showed that the volumes of the front and back cavities tend to change reciprocally and that the areas near the larynx and posterior edge of the hard palate were almost constant throughout the utterance. The lower four formants were calculated from all the area functions and compared with those of natural speech sounds. The mean absolute percent error between calculated and measured formants among all the frames was 4.5%. The comparison of vocal tract shapes for the five vowels with those from the static MRI method suggested a problem of MRI observation of the vocal tract: data from static MRI tend to result in a deviation from natural vocal tract geometry because of the gravity effect.     

A novel strategy for fluorescence enhancement in the solid-state: affording rigidity to fluorophores packing

Solid-state fluorescence enhancement was achieved by preparation of rigid packing that was afforded by disposition of benzylamine into tubulate spaces, serving as a powerful and useful strategy for the enhancement.     

Highly-regulated nanocoatings of polymer films on carbon nanofibers using ultrasonic irradiation

It was demonstrated that nanoprecise coatings of uniform and densely packed polymer layers on nanomaterials and uniform polymer coatings on individual nano-objects are formed using ultrasonic effects.     

Infrared and Raman Spectra and lattice Vibrations of Some Ionic Crystals: Fluorides and Oxides

The infrared and Raman spectra of so-called ionic crystals have been subjects of many investigations by chemists as well as by physicists. These spectra have been interpreted on the basis of a dynamical theory on the long-lattice vibrations of the optical branches by Born and Huang [l]. An interpretation of the optically active lattice vibrations of crystals yields important information regarding the interionic interactions in the crystal. The interatomic interactions in the ionic crystals are divided into the short-range repulsive and long-range electrostatic interactions, while those in the molecular crystals arise primarily from the short-range repulsive ones.