Development of novel fast-disintegrating tablets by direct compression using sucrose stearic acid ester as a disintegration-accelerating agent

It was attempted to produce novel furosemide (FS) fast-disintegrating tablets by direct compression. The combination of FS, microcrystalline cellulose, croscarmellose sodium and xylitol was used as the basic formulation, and sucrose stearic acid ester (SSE) was chosen as an additional additive. The tablets with SSE were prepared by the simple addition of SSE, using a lyophilized mixture of FS and SSE or using a FS/SSE mixture obtained by evaporation of their ethanol solution. Only the tablets, produced using the FS/SSE mixture obtained by organic solvent (ethanol) evaporation, showed hardness of more than 30 N and a disintegration time of less than 20 s, which were the properties suitable for fast-disintegrating tablets. These properties were considered to result from well-mixed and fine-powdered SSE and FS.     

Advanced tip design for liquid phase vibration mode atomic force microscopy

We have fabricated polymer tips for atomic force microscopy in order to elucidate the effects of tip length and shape on cantilever vibration damping in liquids. The vibration damping is investigated by measuring the vibration amplitude of cantilevers as a function of tip-sample distance. The cantilever with a short tip provides a higher damping effect over long tip-sample distances. When the vibration amplitude was rescaled to show the effect of the cantilever width on oscillation damping, the vibration amplitude of cantilevers with various tip lengths was similarly obtained in a long distance range over 50 μm. This similarity is explained by an acoustic damping model in which an acoustic wave is generated by the cantilever. Finally, the results indicate a cantilever with a sufficiently long tip compared to the cantilever width can dramatically reduce the long-range damping effect in a liquid environment.     

Influence of pectins on preparation characteristics of lactoferrin bioadhesive tablets

For the treatment of chronic inflammation in the oral cavity, we attempted to develop bioadhesive tablets of bovine lactoferrin (B-LF). Pectin was used as a bioadhesive polymer, and the influence of the degree of esterification and the molecular weight of pectins on the characteristics of B-LF tablets were investigated. Concerning bioadhesive force, a tendency increasing the value according to increase of the esterification of the pectin was confirmed. Sustained release of B-LF from the tablets was observed as the esterification increased, and a possibility for prediction of the time required to release 50% of B-LF by using the equation given by the degree of esterification and the logarithm of the molecular weight was suggested. Pectin cross-linked with Ca(2+) (Ca-PC) was also used for the preparation of the B-LF tablets. Prolonged release of B-LF from the tablets was observed as the Ca(2+) in Ca-PC increased. Our findings suggest that pectin with a high degree of esterification is suitable as a bioadhesive polymer since high bioadhesive force and sustained release are shown. Furthermore, a possibility that the B-LF release could be controlled by adjusting the Ca(2+) concentration in Ca-PC was suggested.     

Suppressive components in rice husk against mutagens-induced SOS response using Salmonella typhimurium TA1535/pSK1002 umu test

The EtOAc extract from rice (Oriza sativa cv. Hinohikari) husk showed a suppressive effect on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen, Trp-P-1, which requires liver metabolizing enzyme. To obtain the suppressive compound, the EtOAc extract was fractionated by SiO(2) column chromatography using umu test as a bioassay guide. Suppressive compound was isolated and identified as momilactone A (1) by EIMS, IR, (1)H- and (13)C-NMR spectroscopy. Compound 1 inhibited of the SOS-inducing activity of Trp-P-1 in the umu test. Gene expression was suppressed by 32.6% at less than 0.60 mM. Compound 1 was assayed with activated Trp-P-1. The suppressive effect of Compound 1 was decreased compared with that of Trp-P-1. Furthermore, 1 was assayed with another mutagens, such as MeIQ, activated MeIQ, furylfuramide (AF-2), MNNG, and UV-irradiation. Compound 1 showed greater suppressive effect on AF-2-inducing SOS response than other mutagens.     

Concise entry to both enantiomers of 8-oxabicyclo[3.2.1]oct-3-en-2-one based on novel oxidative etherification: formal synthesis of (+)-sundiversifolide

Both enantiomers of 8-oxabicyclo[3.2.1]oct-3-en-2-one (6) have been synthesized from 4-hydroxycyclohept-2-enone (3) on the basis of a novel oxidative cyclo-etherification using PhI(OH)OTs (Koser's reagent). (-)-(1S,5R)-8-Oxabicyclo[3.2.1]oct-3-en-2-one [(-)-6, 95% ee] was expeditiously transformed to (+)-sundiversifolide (1).     

Polarized Raman spectroscopic study on the solvent state of glassy LiCl aqueous solutions and the state of relaxed high-density amorphous ices

We measure polarized OH-stretching Raman spectra of the glassy lithium chloride aqueous solutions (LiClaq solutions) and the relaxed high-density amorphous ices (HDA). The totally OH symmetric vibrational mode around 3100 cm(-1) (g(1) mode) for the glassy LiClaq solutions of 14.3 mol% and the g(1) mode for the glassy LiClaq solution of 10.0 mol% seem to be similar to the g(1) mode for HDA at high pressure and the g(1) mode for HDA at 1 atm, respectively. This indicates that the solvent state of glassy LiClaq solution relates to the state of HDA and that the attenuation of the salt effect on water is equivalent to the attenuation of the pressure effect on water. This suggests a possibility that the hydration in electrolyte aqueous solution may relate to high-density liquid water.     

An X-ray absorption spectroscopic study on mixed conductive La0.6Sr0.4Co0.8Fe0.2O(3-δ) cathodes. I. Electrical conductivity and electronic structure

The electrical conduction mechanism of mixed conductive perovskite oxides, La(0.6)Sr(0.4)Co(0.8)Fe(0.2)O(3-δ), for cathode materials of solid oxide fuel cells has been investigated from electronic structural changes during oxygen vacancy formation. La(0.6)Sr(0.4)Co(0.8)Fe(0.2)O(3-δ) was annealed under various oxygen partial pressures p(O(2))s at 1073 K and quenched. Iodometric titration indicated that the oxygen nonstoichiometry of La(0.6)Sr(0.4)Co(0.8)Fe(0.2)O(3-δ) depended on the annealing p(O(2)), with more oxygen vacancies introduced at lower than at higher p(O(2))s. X-Ray absorption spectroscopic measurements were performed at the O K-, Co L-, Fe L-, Co K-, and Fe K-edges. The valence states of the Co and Fe ions were investigated by the X-ray absorption near edge structure (XANES) at the Co and Fe L(III)-edges. While the Fe average valence was almost constant, the valence of the Co ions decreased with oxygen vacancy introduction. The O K-edge XANES spectra indicated that electrons were injected into the Co 3d/O 2p hybridization state with oxygen vacancy introduction. Both absorption edges at the Co and Fe K-edge XANES shifted towards lower energies with oxygen vacancy introduction. The shift at the Co K-edge resulted from the decrease in the Co average valence and that at the Fe K-edge appeared to be caused by changes in the coordination environment around the Fe ions. The total conductivity of La(0.6)Sr(0.4)Co(0.8)Fe(0.2)O(3-δ) decreased with decreasing p(O(2)), due to a decreasing hole concentration.     

Evidence of instantaneous electron correlation from Compton profiles of crystalline silicon

The combination of new experimental and theoretical techniques provides evidence of instantaneous electron correlation effects in directional Compton profiles of crystalline silicon, which cannot be reproduced when reference is made to a density matrix obtained from a single-determinantal wavefunction. These effects are instead accounted for by a recently implemented post-Hartree-Fock periodic scheme, which gives results in quite good agreement with the high-quality experimental data.     

SEM and TEM Observation of Carbon Nano-Fibers Prepared by Hot Filament Assisted Sputtering

Abstract

Carbon films were prepared by hot filament assisted sputtering. Pure argon was used as the sputtering gas. The substrate temperature was 600 °C and the filament temperature was about 2000 °C. Sample was inhomogeneous. Scanning electron microscope (SEM) and transmission electron microscope (TEM) images showed that some part of films consisted of carbon nano fibers (not hollow but solid). Amorphous and polycrystalline phases were also detected by these measurements. No tube structure was observed by high resolution TEM. The diameter of the fiber was 10–30 nm.