Kurashiki University of Science and the Arts

Kurashiki, Japan

Kurashiki University of Science and the Arts is a private university in Kurashiki, Okayama, Japan, established in 1995. Wikipedia.

Time filter
Source Type

Shimoda K.,Oita University | Imai H.,Okayama University of Science | Mandai T.,Kurashiki University of Science and the Arts | Hamada H.,Okayama University of Science
Natural Product Communications | Year: 2012

Time course experiment revealed that cultured plant cells of Eucalyptus perriniana regioselectively glucosylated silybin to silybin-23-β-D- glucoside in up to 70% yield.

Arai M.A.,Chiba University | Tateno C.,Chiba University | Koyano T.,Temko Corporation | Kowithayakorn T.,Khon Kaen University | And 2 more authors.
Organic and Biomolecular Chemistry | Year: 2011

The aberrant hedgehog (Hh)/GLI signaling pathway causes the formation and progression of a variety of tumors. We recently constructed a cell-based screening system to search for Hh/GLI signaling inhibitors from natural resources. Using our screening system, Adenium obesum was found to include Hh/GLI signaling inhibitors from our tropical plant extract libraries. Bioassay-guided fractionation of this plant extract led to the isolation of 17 cardiac glycosides (1-17), including 3 new compounds (4, 9, 16). These compounds showed strong inhibitory activities, especially the IC50 of 17 is 0.11 μM. The inhibition of GLI-related protein expression with 3, 9, 11, 15 and 17 was observed in human pancreatic cancer cells (PANC1), which express Hh/GLI components aberrantly. The expressions of GLI-related proteins PTCH and BCL2 were clearly inhibited. These compounds also showed selective cytotoxicity against two cancer cell lines, with less effect against normal cells (C3H10T1/2). RT-PCT examinations showed that Ptch mRNA expression by 3, 11, 15 and 17 was inhibited. © 2011 The Royal Society of Chemistry.

Kusano Y.,Kurashiki University of Science and the Arts | Fukuhara M.,Okayama University of Science | Takada J.,Okayama University | Doi A.,Kurashiki University of Science and the Arts | And 2 more authors.
Accounts of Chemical Research | Year: 2010

Bizen stoneware, with the characteristic reddish hidasuki or "fire-marked" pattern, is one of Japans best known traditional ceramic works of art. The means of creating and controlling the various hues of the hidasuki pattern has remained a mystery to outsiders for about a thousand years; the methods were known only to master potters who served under generations of master potters before them. In this Account, we present the results of 30 years of study in which we investigated the microstructure and color-formation process in Bizen stoneware. We discovered that the hidasuki pattern results from the precipitation of corundum (α-Al2O3) and the subsequent epitaxial growth of hematite (α-Fe2O3) around it in a -50-m-thick liquid specifically formed in the ceramic surface. The epitaxial composites include hexagonal plate-like α-Fe 2O3/α-Al2O3/α-Fe 2O3 sandwiched particles and also surprisingly beautiful flower-like crystals, centered by hexagonal corundum crystals and decorated by several hexagonal hematite petal crystals. Bizen stoneware is produced from a unique clay that can only be mined from the Bizen area of Okayama Prefecture, Japan. The clay has an unusually high Fe content compared with the traditional porcelain clay, as well as Si, Ca, Mg, and Na. Prior to firing, the Bizen works are wrapped in rice straw that was used originally as a separator to prevent adhesion. The hidasuki pattern only appears where the rice straw is in direct contact with the clay; the rice straw supplies potassium, which reduces the melting point of the ceramic surface, thereby converting the contact area into a site for these reactions to take place. The effect is almost accidental and is produced without the aid of any artificial glazing and enameling. An unexpected variety of substances, including metallic iron coated by graphite, Fe 3P, and ε-Fe2O3, were also found to appear at low oxygen partial pressures. Many of the techniques used by master potters are passed down through an apprenticeship system; an unfortunate consequence is that they are poorly documented. Moreover, the masters of these techniques are often unaware of the underlying chemical reactions that take place. Chemical studies of traditional processes can provide new inspiration to artists, allowing them to control the various factors and thus produce new works, and perhaps new functional materials. We studied the process of creating Bizen stoneware and then mimicked the color-producing process under controlled laboratory conditions, demonstrating the possibilities of the endeavor. © 2010 American Chemical Society.

Kobayashi Y.,Kyoto University | Hernandez O.J.,CNRS Chemistry Institute of Rennes | Sakaguchi T.,Kyoto University | Yajima T.,Kyoto University | And 20 more authors.
Nature Materials | Year: 2012

In oxides, the substitution of non-oxide anions (F -S 2-N 3- and so on) for oxide introduces many properties, but the least commonly encountered substitution is where the hydride anion (H-) replaces oxygen to form an oxyhydride. Only a handful of oxyhydrides have been reported, mainly with electropositive main group elements or as layered cobalt oxides with unusually low oxidation states. Here, we present an oxyhydride of the perhaps most well-known perovskite, BaTiO3, as an O 2-/H-solid solution with hydride concentrations up to 20% of the anion sites. BaTiO3-x Hx is electronically conducting, and stable in air and water at ambient conditions. Furthermore, the hydride species is exchangeable with hydrogen gas at 400°C. Such an exchange implies diffusion of hydride, and interesting diffusion mechanisms specific to hydrogen may be at play. Moreover, such a labile anion in an oxide framework should be useful in further expanding the mixed-anion chemistry of the solid state. © 2012 Macmillan Publishers Limited. All rights reserved.

Ishikawa M.,Hiroshima University | Naka A.,Kurashiki University of Science and the Arts | Yoshizawa K.,Kyushu University
Dalton Transactions | Year: 2016

The synthesis and reactions of 3,4-benzo-1,2-disilacyclobut-3-enes and benzo[1,2:4,5]bis(1,2-disilacyclobut-3-ene)s developed by our group are reported in this review. The palladium-, platinum- and nickel-catalyzed reactions of benzodisilacyclobutenes and benzobis(disilacyclobutene)s with unsaturated compounds afford various types of products. The structures of the products are dependent upon the nature of the transition metal used as a catalyst. The reactions of cis- and trans-benzodisilacyclobutenes with alkenes and alkynes in the presence of a transition-metal catalyst proceed with high stereospecificity to give the respective adducts. The thermal reactions of cis- and trans-benzodisilacyclobutenes with various substrates also proceed stereospecifically to give adducts. The results of theoretical calculations for the platinum-catalyzed reaction of disilacyclobutene with acetylene, the nickel-catalyzed reaction of benzodisilacyclobutene and the thermal reaction of benzobis(disilacyclobutene) are discussed in this review. © The Royal Society of Chemistry 2016.

Ishizuka Y.,Kurashiki University of Science and the Arts | Kikuchi T.,Ritsumeikan University
Open Bioinformatics Journal | Year: 2011

The sequences of azurin and titin, β sandwich proteins, are analyzed based on inter-residue average distance statistics. A kind of predicted contact map based on inter-residue average distance statistics (Average Distance Map, ADM) is used to pinpoint regions of possible compact regions for two proteins. We compare predicted compact regions with the positions of the residues with experimental high φ values for these proteins reported in the literature. The results reveal that the regions predicted by ADMs correspond to the positions of residues with the high φ value. Furthermore, we perform random sampling of 3D conformations using these protein sequences with a potential derived from inter-residue average distance statistics. It is demonstrated that the residues with highest contact frequency during the simulations qualitatively correspond to the residues with the highest φ values for these proteins. Importantly, analysis with inter-residue average distance statistics predicts the properties of folding processes of the β sandwich proteins starting from only sequence information. © Ishizuka and Kikuchi.

Yamamoto S.,Kyoto University | Kusano Y.,Kurashiki University of Science and the Arts
Chemistry Letters | Year: 2016

A method to prepare FePt/PbS core/shell nanoparticles with a controllable PbS thickness (dPbS) based on the reaction of lead oleate and sulfur in the presence of FePt nanoparticles has been developed. It was demonstrated that dPbS can be finely controlled from ca. 0.5 to 4.3nm by adjusting the reaction temperature and/or the time. The resulting FePt/PbS core/shell nanoparticles with various dPbS's showed smaller magnetic anisotropies than those of the pristine FePt nanoparticles. The observed anisotropies were almost constant and independent of dPbS. This result indicates that it is the surface anisotropy and not the interparticle magnetic dipolar interactions that predominantly determines the magnetic properties of the FePt/PbS core/shell nanoparticles. © 2016 The Chemical Society of Japan.

Teng Y.,Kyoto University | Yamamoto S.,Kyoto University | Kusano Y.,Kurashiki University of Science and the Arts | Azuma M.,Kyoto University | Shimakawa Y.,Kyoto University
Materials Letters | Year: 2010

Cubic Co3O4 nanocrystals (NCs) were synthesized by a one-pot hydrothermal reaction in the presence of the oxidant KClO3 and the capping reagent polyvinylpyrrolidone (PVP). The as-prepared Co3O4 NCs were uniformly cubic with sharp edges and good crystallinity and showed flat surfaces with {100} facets. The capped PVP could be removed without losing cubic shape by heating the NCs at 300 °C. © 2009 Elsevier B.V. All rights reserved.

Danno T.,Okayama University | Nakatsuka D.,Okayama University | Kusano Y.,Kurashiki University of Science and the Arts | Asaoka H.,Okayama University | And 4 more authors.
Crystal Growth and Design | Year: 2013

β-Fe2O3 is the scarce polymorph of Fe 2O3 phases and is transformed easily into α-Fe 2O3 at high temperature. However, its crystal structure and the transformation mechanism to α-Fe2O3 are still unclear because of the difficulty in obtaining monophasic β-Fe 2O3 crystals. We established a synthesis method of the monophasic β-Fe2O3. It was synthesized by a two-step reaction: heating a mixture of Na2SO4 and Fe 2(SO4)3 in air at 250 C to form NaFe(SO 4)2, and subsequent heating the resultant phase with NaCl in air at 500 C. The crystal structure was refined to a bixbyite-type cubic structure (Ia3Ì...) with a = 9.4039(1) Å by the Rietveld method. Single crystalline β-Fe2O3 particles of approximately 1 μm in size were topotactically transformed into single α-Fe 2O3 crystals. Electron diffraction analysis revealed the crystallographic orientation relationships between β-Fe2O 3 and α-Fe2O3 to be [100] β//[0001]α, [010]β// [101Ì...0]α, and [001]β//[1Ì... 21Ì...0]α. © 2013 American Chemical Society.

Tanaka H.,Kyushu University | Shiota Y.,Kyushu University | Hori K.,Kyushu University | Naka A.,Kurashiki University of Science and the Arts | And 2 more authors.
Organometallics | Year: 2012

Thermal reactions of a silene derivative (Me 3Si) 2Si=C(OSiMe 3)(t-Bu) (1) with silyl-substituted acetylenes, bis(trimethylsilyl)butadiyne, tert-butyldimethylsilylacetylene, and bis(trimethylsilyl)acetylene have been investigated with density functional theory calculations for the understanding of substituent effects in the reactivity of the silene. The first critical reaction step for determining the final product is the formation of a biradical intermediate from 1 and the acetylenes. A stepwise [2 + 2] cycloaddition via the biradical intermediate gives a silacyclobutene derivative, which is the precursor of the final product. The activation energy for this reaction step as well as thermodynamic stability of the biradical intermediate is governed by an interplay between geometric and electronic factors. The biradical intermediate is destabilized by steric hindrance between bulky substituents on 1 and acetylene, while it can be stabilized by delocalization of an unpaired electron in the acetylene moiety. Silacyclobutene derivatives undergo Si-C bond cleavage to give silabutadiene derivatives. The second critical reaction step is the attack of the OSiMe 3 group on the silene Si atom in the silabutadienes. If the substituent on one of the acetylene C atoms does not easily migrate, the SiMe 3 group of the OSiMe 3 group rebounds to the silene C atom to form an oxasilacyclopentene derivative. If this substituent migrates easily, on the other hand, it migrates to the silene C atom with a simultaneous migration of the OSiMe 3 group, resulting in the formation of an allene derivative. © 2012 American Chemical Society.

Loading Kurashiki University of Science and the Arts collaborators
Loading Kurashiki University of Science and the Arts collaborators