Dehydrogenation of isopropylbenzene with vanadium-oxide-loaded activated carbon catalyst in the presence of carbon dioxide

Dehydrogenation of isopropylbenzene to α-methylstyrene was carried out using various supported metal oxide catalysts in the presence of carbon dioxide. An activated carbon-supported vanadium oxide catalyst afforded a high activity in carbon dioxide atmosphere: the α-methylstyrene yield in carbon dioxide atmosphere was two times greater than that in an argon atmosphere at 723 K. In order to investigate the role of carbon dioxide in this reaction, we carried out temperature-programmed reduction (TPR) studies using both fresh and used catalysts. The TPR profiles clearly indicate that carbon dioxide could keep the surface of vanadium oxide at a high oxidation state. This revised version was published online in July 2006 with corrections to the Cover Date.     

High-quality cutting of polished single-crystal silicon by wire electrical discharge machining

We discussed a method for cutting smoothly polished single-crystal silicon surfaces by wire electrical discharge machining to obtain a high-quality surface. To cut out parts with smooth surfaces from the plates by rough-cutting in water while maintaining the initial smoothness of the surfaces, several kinds of masks were applied to the polished surfaces before cutting. It was found that although the application of resin masks is effective for obtaining smooth surfaces far from the cut section, the surface smoothness near the section cut in water is less than in the case of cutting in oil. Next, finish-cutting in oil was performed to remove cracks and chips generated by rough-cutting in oil. As a result, although a few chips were generated at edges of the cut section, cracks were successfully removed by finish-cutting, so that the surface quality was successfully improved by finish-cutting in oil.     

Anti-influenza A virus effects of fructan from Welsh onion (Allium fistulosum L.)

A fructan that acts as an anti-influenza A virus substance was isolated from hot water extract of the green leafy part of a Welsh onion (Allium fistulosum L.). The structure of the fructan was characterised and elucidated by chemical and spectroscopic analyses. The fructan was composed of terminal (21.0%) and 2,1-linked β-d-Fruf residues (65.3%) with 1,6-linked β-d-Glcp residues (13.7%). The molecular weight of the polysaccharide and polydispersity was estimated to be 1.5 × 10³ and 1.18, respectively. Although the fructan did not show anti-influenza A virus activity in vitro, it demonstrated an inhibitory effect on virus replication in vivo when it was orally administered to mice. In addition, the polysaccharide enhanced the production of neutralising antibodies against influenza A virus. Therefore, the antiviral mechanism of the polysaccharide seemed to be dependent on the host immune system, i.e., enhancement of the host immune function was achieved by the administration of the polysaccharide. From our observations, the fructan from Welsh onions is suggested to be one of the active principles which exert an anti-influenza virus effect.     

The effect of fullerene doping on photoelectric conversion using titanyl phthalocyanine and a perylene pigment

The effect of fullerene (C₆₀) doping on photoelectric conversion using titanyl phthalocyanine (TiOPc) and a perylene pigment, N, N′-dimethyl-3,4 : 9,10-perylenebis(dicarboximide) (MPCI), was investigated. A new three-layer cell, ITO/MPCI/C₆₀-doped TiOPc/TiOPc/Au, exhibited a higher quantum yield for charge-carrier photogeneration than a two-layer cell without the C₆₀-doped TiOPc layer, ITO/MPCI/TiOPc/Au, upon irradiation with monochromatic light which TiOPc mainly absorbs. The three-layer cell showed a high conversion efficiency of 0.63% for incident white light at an intensity of ca. 100 mW cm⁻².     

Abstracts: The effects of Coptis japonica root extract and its key component,berberine, on human subcutaneous adipocytes

pp.274–280 An increase of subcutaneous fat presses lymph vessels and blood vessels in skin tissues, and results in not only causing skin troubles such as skin sagging and swelling but also forming cellulite that makes bodylines worse. To expand further application of plant extracts to cosmetics, we focused on inhibitory effects of subcutaneous preadipocytes differentiation and facilitating lipolysis in adipocytes. In this study, in a screening test of a number of plant extracts, Coptis japonica root extract and its key component, berberine, showed potent inhibition of triglyceride accumulation and subcutaneous preadipocytes differentiation. Furthermore, Coptis japonica root extract and berberine down‐regulated the mRNA expression level of several differentiation factors derived from subcutaneous preadipocytes. Coptis japonica root extract and berberine in subcutaneous adipocytes facilitated lipolysis in mature adipocytes. Our study suggested that Coptis japonica root extract and its key component, berberine, is expected to be useful for slimming and related skin troubles such as skin sagging, swelling, cellulite, and so on.     

Maleated trans-1,4-polyisoprene from Eucommia ulmoides Oliver with dynamic network structure and its shape memory property

We developed a bio-based shape memory polymer with dynamically crosslinked network structure from trans-1,4-polyisoprene (TPI) derived from Eucommia ulmoides Oliver. Grafting of maleic anhydride onto TPI was performed in 1,2-dichlorobenzene, and the subsequent hydrolysis gave maleated trans-1,4-polyisoprene (MTPI). Increasing trend of the grafted maleic moiety was observed with increasing the concentration of maleic anhydride in the grafting reaction. With increase in maleic content, the glass transition temperature (T_g) of the resulting polymer increased, whereas the crystallinity decreased. The maximum stress of the MTPI with carboxylates was larger than that of the protonated MTPI. Above the melting temperature, the Young's modulus of MTPI with carboxylates was higher than that of neat TPI and the protonated MTPI, due to dynamically crosslinked network structure. Furthermore, the MTPI with 1% carboxylate content exhibited excellent shape memory-recovery properties, exploiting the combination of the physical crosslinking and the melting of the crystal. The resulting materials are expected to contribute to the development of bio-based intelligent materials.     

Mass spectrometry for the study of protein glycation in disease

The structural elucidation of advanced glycation end-product (AGE)-modified proteins and quantitative analysis of free AGEs have been successfully performed, by use of mass spectrometry (MS) in plasma and tissues of patients with AGE-related diseases, such as diabetes mellitus, uremia, cataract, and liver cirrhosis. Matrix-assisted laser desorption/ionization (MALDI)-MS made it possible to directly analyze the AGE-modified proteins such as albumin and IgG. However, because the direct structural analysis of intact AGE-modified proteins is often not easy due to the formation of broad and poorly resolved peaks, peptide mapping after enzymatic hydrolysis was introduced into the analysis of AGE-modified proteins and the site-specific analysis of defined AGEs by MALDI-MS. Liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) has been employed not only for the structural elucidation of enzymatically hydrolyzed AGEs-modified peptides but also for simultaneous quantification of free AGEs in plasma and tissues of patients. Based on many studies that use MS for the analysis of AGEs, there is no doubt as to the important role of protein-linked AGEs in several diseases.     

Coal liquefaction using iron complexes as catalysts

Hydroliquefaction of Japanese Miike and Taiheiyo coals was carried out using various iron complexes as catalysts in tetralin at 375–445 °C. Iron pentacarbonyl (Fe(CO)₅) showed the highest catalytic activity, increasing coal conversion by about 10% at 425 °C under an initial hydrogen pressure of 5 MPa. Amounts of hydrogen transferred to coal increased from 1.4–2.3 wt% of daf coal in the absence of the catalyst to 2.5–4.2 wt% of daf coal in the presence of Fe(CO)₅ at 425 °C.     

Radiation Efficiency of Partially Coherent Three-dimensional Sources

Abstract

Radiation efficiency, which is defined as the total power radiated from a source normalized to a maximum value of unity, is investigated theoretically for a partially coherent three-dimensional source. The source model for analysis is assumed to be a primary, homogeneous, isotropic spherical source, and its spatial correlation is characterized by means of properly arranged Bessel functions. A number of representative curves of the radiation efficiency are illustrated as a function of the coherence condition of the source and compared with the curves of the radiation efficiency for the planar source whose spatial coherence is specified by the same functional form of Bessel functions. It is found from such comparison that there exists a kind of reciprocal behaviour in radiation efficiency between the three-dimensional source and the planar one.     

Fraunhofer Diffraction by Koch Fractals

Abstract

Analytical expressions are derived for the complex amplitude in the Fraunhofer diffraction field of an arbitrary Koch fractal with a finite range of self-similarity. Results of the numerical evaluation for the intensity distribution of Fraunhofer diffraction patterns are compared with those obtained experimentally. It is shown that the diffraction pattern of the Koch fractal can be divided into two areas, a central fractal area and a periodic area, and that the former is surrounded by the latter. The existence of the periodic area is a consequence of the finite inner cut-off of the self-similarity of the object fractal. On the other hand, the outer cut-off gives rise to a small core area at the centre of the diffraction pattern.