記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Foods  

The Maypole apple is a new, promising species of small apples with a prominent flavor and deep red flesh and peel. This study divided Maypole apples into outer flesh, inner flesh, and peel, and used subcritical water at 100–175 °C for 10–30 min to extract various phytochemicals (procyanidin B2 (PB2), 5-caffeoylquinic acid (5CQA), and epicatechin). The obtained Maypole apple extracts and extraction residues in this work were analyzed using a SEM, HPLC, FT-IR, and UV-Vis spectrophotometer. Under different subcritical water extraction conditions, this work found the highest extraction rate: to be PB2 from the peel (4.167 mg/mL), 5CQA (2.296 mg/mL) and epicatechin (1.044 mg/mL) from the inner flesh. In addition, this work regressed the quadratic equations of the specific yield through ANOVA and found that temperature is a more significant affecting factor than extraction time. This aspect of the study suggests that phytochemicals could be obtained from the Maypole apple using the new extraction method of subcritical water.

DOI： 10.3390/foods11213453

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Environmental Chemical Engineering  

Carbon-encapsulated TiO2, Ag and Fe3O4 NPs are synthesized by pulse arc discharge plasma over glycine aqueous solution under high pressures, which is a novel plasma technique to fabricate metal-based NPs/C nanocomposites in one step. The carbon coatings are formed by utilizing glycine as a carbon precursor and confirmed to be amorphous carbon. While TiO2, Ag and Fe3O4 NPs are generated instantaneously via the erosion of the metal electrodes and reaction with the active oxidation radicals and molecular produced during the plasma generation over gas/liquid interface. It was found that the NPs are produced in the uniform size only under high operating pressure and the average size of the TiO2, Ag and Fe3O4 NPs were around 10.2 nm, 6.6 nm and 9.6 nm, respectively. The pulse arc discharge plasma was performed in different pressures, glycine concentrations and pulse times to investigate the effect of the influential factors on the formation of the carbon-encapsulated NPs in this plasma system. The carbon-encapsulated NPs are later annealed at 800 °C under Ar gas to construct the porous structure. In the MB degradation test, the porous carbon-encapsulated TiO2 NPs exhibit good adsorption capacity and improved photocatalytic activity.

DOI： 10.1016/j.jece.2022.107771

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Polymers  

Electrospun fibers containing tea tree oil (TTO) can be explored for practical applications due to the antimicrobial and anti-inflammatory activities of TTO. Considering that there are poten-tially toxic components in TTO, it is necessary to eliminate or reduce its content in the preparation process of TTO-doped electrospun fibers. In this work, electrospun TTO-PVP (polyvinylpyrrolidone) fibers containing an 18.18 wt.% decreased content of 1,8-Cineole were successfully fabricated by intense evaporation of a self-made reduced-pressure electrospinning (RP-ES) setup (as low as 94.4 kPa). In addition, such intense evaporation led to a morphology change, where a typical average fiber diameter increased from 0.831 to 1.148 µm, fewer and smaller beads in fibers, along with a rougher and grooves fiber surface. These morphology changes allowed Terpinen-4-ol to remain in the fiber for a more extended period. In addition, RP-ES proved the possibility for intense evaporation and continuous vapor removal by continuously environmental vacuum pumping of electrospinning.

DOI： 10.3390/polym14040743

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Polymers  

Silver nanoparticles (AgNPs) are novel materials with antibacterial, antifungal, and antiviral activities over a wide range. This study aimed to prepare polyvinylpyrrolidone (PVP) electrospinning composites with uniformly distributed AgNPs. In this study, starch-capped ~2 nm primary AgNPs were first synthesized using Atmospheric pressure Pulsed Discharge Plasma (APDP) at AC 10 kV and 10 kHz. Then, 0.6 wt.% AgNPs were mixed into a 10 wt.% PVP ethanol-based polymer solution and coiled through an Ultrasonic-assisted Electrospinning device (US-ES) with a 50 W and 50 kHz ultrasonic generator. At 12 kV and a distance of 10 cm, this work successfully fabricated AgNPs-PVP electrospun fibers. The electrospun products were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), High-Resolution TEM (HR-TEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Thermogravimetric (TG), and X-ray Photoelectron Spectroscopy (XPS) methods.

DOI： 10.3390/polym14030599

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Polymers  

Polyvinylpyrrolidone (PVP) is used in a wide variety of applications because of its unique chemical and physical features, including its biocompatibility and low toxicity. In this study, hollow PVP/silver nanoparticle (PVP/Ag NP) composite fibers were synthesized. Stable, spherical Ag NPs, with an average size of 14.4 nm, were produced through a facile sonochemical reduction method. A small amount of starch as a potent reducing and stabilizing agent was used during the reduction of Ag ions to Ag NPs. The fabricated Ag NPs were then added to a 10 wt% PVP-dichloromethane (DCM) solution, which was utilized as an electrospinning feed solution under a dense carbon dioxide (CO2) environment at 313 K and 5 MPa and an applied voltage of 15 kV. The dense CO2 enabled rapid extraction of DCM from the PVP-Ag NPs-DCM solution, which was then dissolved into PVP/Ag NPs, resulting in a hollow structure. Scanning electron microscopy, Fourier-transform infrared (FT-iR) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses, and thermogravimetric analysis (TGA), were used to characterize the electrospinning products.

DOI： 10.3390/polym14010089

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACS Omega  

Cerium dioxide (CeO2) nanoparticles have gained immense attention owing to their use in various applications. Current synthesis methods for CeO2 nanoparticles including hydrothermal and chemical precipitation are time-consuming and require chemical reagents. In order to shorten the reaction time and avoid the use of organic reagents, a new method for CeO2 nanoparticles synthesis in a slug flow system by atmospheric-pressure pulsed discharge plasma was proposed, which provided an easy, efficient, and continuous reaction at room temperature. Cerium nitrate was used as a feed solution, and starch was added as a stabilizer to separate the nucleation and growth processes of the nanoparticles to prevent their aggregation. The system was powered by a high voltage of 10.0 kV (peak-to-peak) from an ac power supply. The products were characterized by transmission electron microscopy (TEM), high-resolution TEM, energy-dispersive X-ray spectroscopy, and UV-vis spectroscopy. The results showed that when a circular capillary glass tube coil was used as the slug flow reactor, the amount of the CeO2 nanoparticles increased compared to the case when a straight glass tube was used. The size also increased from 3.4 to 6.3 nm. The synthesis mechanism of the CeO2 nanoparticles by gas/liquid plasma was finally elucidated.

DOI： 10.1021/acsomega.1c02463

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開催年月日： 2023年3月

記述言語：日本語   会議種別：ポスター発表  

国名：日本国  

開催年月日： 2022年11月

記述言語：日本語   会議種別：ポスター発表  

開催地：オンライン  

開催年月日： 2021年5月

記述言語：英語   会議種別：ポスター発表  

開催年月日： 2019年9月

記述言語：英語   会議種別：口頭発表（一般）