Publications by authors named "Miyakoshi Tetsuo"

Six optically active (Z)-7-decen-4-olide derivatives (1a-1f) were synthesized in 99% enantiomeric excess using diastereomeric resolution. The odour properties of the racemic and optically active 1a-1f were evaluated in terms of their orthonasal aromas. All of the stereoisomers had different odour characteristics and thresholds.

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In this study, the effect of glass fiber powder on the properties of waterborne coatings with thermochromic ink was investigated, using Chinese fir board as the base material and temperature-sensitive thermochromic waterborne coatings with thermochromic ink as the paint base. The concentration of glass fiber powder was determined when the microstructure, optical properties, mechanical properties, liquid resistance, and heat preservation effect were the best. The results showed that the paint film with glass fiber powder concentration of 1.

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In this study, veneer was dyed with reactive brilliant red X-3B, black KN-B and blue K-3R dyes. The dye concentration, bath ratio and dyeing time were selected for an orthogonal experiment. Analysis of variance showed that the dye concentration had the greatest effect on the dye uptake of veneer.

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Volatile organic compounds (VOCs) are an important factor affecting ambient air quality, and furniture production is one of the important sources of VOC pollution. High VOC concentrations have adverse effects on the environment and worker welfare in furniture factories. In order to control VOC emissions in a furniture workshop, the VOC species and concentration distributions were examined.

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Objectives: Structural brain magnetic resonance imaging studies of individuals at ultra-high risk (UHR) for psychosis have shown subtle but widespread reductions in baseline gray matter volume (GMV) in the frontal, temporal, and limbic regions compared with healthy controls (HC). These regions coincide with regions of reduced GMV in patients with established psychosis and have led to the consideration of structural changes in UHR as a potential biomarker for future transition to psychosis. However, most studies have been from Europe, North America, and Australia, with few reports from other regions, and two recent studies from Asian countries have failed to detect regional GMV reduction in UHR, suggesting the need for further analysis of an Asian sample.

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A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of lacquer saps with potential applications to analysis of Asian lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation.

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The chemical structure of fresh lacquer sap collected from a lacquer tree growing in Nago City of Okinawa, Japan, was analyzed by gas chromatography/mass-spectrometry (GC/MS) and nuclear magnetic resonance (NMR). The results showed that Nago lacquer is laccol lacquer and its major components are 3-(heptadeca-10Z,13E,15E-trienyl)catechol, 3-(heptadeca-10Z,13E-dienyl)catechol, 3-(heptadeca-14Z-enyl)catechol, and 3-(heptadeca-12Z-enyl)catechol, which are similar to the components of Vietnamese lacquer. It showed higher laccase activity at pH 5 - 8 and better low temperature adaptability than Vietnamese lacquer.

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Expressed emotion (EE), especially criticism, is an important predictor of outcomes for the patient for a wide range of mental health problems. To understand complex links between EE and various relevant variables in early phase psychosis, this study examined criticism, distress of caregivers, other patients', and caregivers' variables, and links between criticism and these variables in those with at-risk mental state (ARMS) for psychosis and first-episode psychosis (FEP). The participants were 56 patients (mean age 18.

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A combination of Novozym 435-catalyzed methanolysis and amidation using racemic N-methyl-5-acetoxytridecan- and tetradecanamides as a substrate proceeded in good enantioselectivity to afford the corresponding (R)-N-methyl-5-acetoxyalkanamides, (S)-N-methyl-5-hydroxyalkanamides, and (S)-N-cyclohexyl-5-hydroxyalkanamides. Both enantiomers of δ-tri- and δ-tetradecalactones were synthesized in over 90% enantiomeric excesses from the corresponding (R)- or (S)-alkanamides. Addition of cyclohexylamine to Novozym 435-catalyzed methanolysis shortened 24-hour reaction time to reach about 50% conversion.

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Article Synopsis
  • A new method for creating enantiomerically enriched δ-hexadecalactone (3) is proposed, using the enzymatic kinetic resolution of N-methyl-5-acetoxyhexadecanamide (1).
  • The method involves lipase-catalyzed hydrolysis and amidation to enhance the enantioselectivity of the process.
  • The research found that adding cyclohexylamine during the lipase-catalyzed hydrolysis yielded both enantiomers of compound 3 with over 90% enantiomeric excess.
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Synthesis of optically pure δ-lactones by diastereomeric resolution was investigated. Amino acid derivatives, which can be obtained at a relatively low cost, were used as resolving agents. Six optically pure δ-lactones were efficiently synthesized using Cbz-L-alanine without other expensive resolving agents.

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Objective: The notion of at-risk mental state (ARMS) is valuable for identifying individuals in a putative prodromal state of psychosis and for reducing conversion risk by pharmacological and psychological interventions. However, further systematic study is required because 1) diagnostic reliability in various clinical settings is not yet established; 2) predictive ability is insufficient; 3) optimal interventions in diversified populations are elusive; and 4) little evidence from non-Western regions exists.

Methods: A naturalistic longitudinal study was conducted at a specialized clinic for early psychosis at a university hospital in Sendai, Japan.

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Cognitive insight, defined as the ability to evaluate and correct one׳s own distorted beliefs and misinterpretations, is hypothesized to contribute to the development of psychotic symptoms. We investigated cognitive insight in individuals with at-risk mental state (ARMS), which is associated with a clinically high risk of psychosis. Sixty individuals with ARMS were compared with 200 healthy controls in terms of cognitive insight measured using the Beck Cognitive Insight Scale.

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Various hydroxycinnamoyl β-d-xylopyranosides were efficiently prepared from 2,3,4-tri-O-acetyl-α-d-xylopyranosyl bromide (TAXB) with amine by amine-promoted glycosylation. The resulted acetylated hydroxycinnamoyl β-d-xylopyranosides with acetoxy groups at C-2, C-3, and C-4 were regioselectively deacetylated at C-4 position with Novozym 435. Antioxidant activities of free hydroxycinnamic acids and the respective β-d-xylopyranosides were evaluated by DPPH radical scavenging activity as well as their inhibitory effect on autoxidation of bulk methyl linoleate.

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Aims: The recognition of emotion is often impaired in patients with schizophrenia. The relationship of this deficit with symptoms of psychosis remains unclear. In the current study, we investigated the relationship between emotional processing and positive psychotic symptoms in schizophrenia.

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Various glycosyl ferulates were efficiently synthesized from 2,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (TAGB) with amine by amine-promoted glycosylation without using heavy metal. The resulted acetylated glycosyl ferulates with acetoxyl groups at C-2, C-3 and C-4 were regioselectively deacetylated at C-4 and C-6 positions with Novozym 435. Antioxidant abilities of free ferulic acids and its synthetic glycosyl ferulates were evaluated by inhibitory effect on autoxidation of bulk methyl linoleate as well as their radical scavenging activity.

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The competition between benzylic cleavage (simple bond fission [SBF]) and retro-ene rearrangement (RER) from ionised ortho, meta and para RC(6) H(4) OH and RC(6) H(4) OCH(3) (R = n-C(3) H(7) , n-C(4) H(9) , n-C(5) H(11) , n-C(7) H(15) , n-C(9) H(19) , n-C(15) H(31) ) is examined. It is observed that the SBF/RER ratio is significantly influenced by the position of the substituent on the aromatic ring. As a rule, phenols and anisoles substituted by an alkyl group in meta position lead to more abundant methylene-2,4-cyclohexadiene cations (RER fragmentation) than their ortho and para homologues.

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Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera) from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110 kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined.

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Several important monolignols such as coniferyl alcohol were catalyzed using Rhus laccase (RL) from Rhus vernicifera in a water/acetone solution. The enzymatic mechanism is discussed in detail. Sites 6, β, and phenolic oxygen were the main active sites of phenylpropanoid compounds, which were first oxidized by the enzyme and then radicalized.

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This paper focuses on the identification of several chemical markers of vegetal species of Oriental lacquers with the aim at providing a methodology consistent with sampling restrictions necessarily applied in the field of cultural heritage. The method proposed is based on rapid and easy single step thermally assisted hydrolysis-methylation (THM) pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis that can be carried out with a minimum amount of matter (typically 10 μg for a sample collected on a museum or an archaeological object). The main contribution of this study is to provide multiple molecular criteria for discriminating the three Asian species used for making lacquers, namely Rhus verniciflua Stokes, Rhus succedanea and Melanorrhoea usitata.

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Allergic contact dermatitis caused by contact with lacquer sap and lacquerware affects the welfare of lacquer workers and the lacquerware industry. Many studies of the mechanism of urushiol allergy, including animal models, have been carried out and have established several hypotheses. In order to provide a comprehensive understanding of lacquer allergy, we review recent advances in the research on lacquer allergy including the chemical properties of lacquer lipid components, allergic mechanism analyses, immunological explanations, allergy medications, and the prevention combined with the research results from our laboratory.

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We examined the dissolution of polystyrene (PS) into acyclic monoterpenes present in tree essential oils, to develop an environmentally friendly shrinking agent for waste-expanded polystyrene (EPS). The dissolving powers of geranyl acetate, geranylacetone, and geranyl formate [221.8-241.

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Rhus laccase (RL) was covalently immobilised onto chitosan, and the effects of immobilisation on pH optimum, enzyme activity, thermostability, and re-use evaluated, using either N,N-dimethyl-p-phenylenediamine or 2,6-dimethoxyphenol as substrate. Immobilisation greatly enhanced enzyme thermostability, resulted in negligible loss of activity, and showed excellent re-use potential, with >80% relative activity retained after 15 cycles in aqueous solvent. Immobilised Rhus laccase (I-RL) was more catalytically active in both hydrophobic and hydrophilic organic solvents than free RL.

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