研究者詳細 - 今中　洋行

論文 - 今中　洋行

分割表示 110 件中 21 - 40 件目／全件表示 >>

Influence of an external electric field on removal of protein fouling on a stainless steel surface by proteolytic enzymes 査読

Ei Ei Htwe, Yuhi Nakama, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

COLLOIDS AND SURFACES B-BIOINTERFACES 159 118 - 124 2017年11月

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

Enzymatic cleaning is a potentially useful method for removing proteinaceous fouling from solid surfaces under mild conditions. Herein, the influence of an external electric field on the enzymatic cleaning of a metal surface fouled with a protein was investigated. The model fouling protein (BSA; lysozyme) was prepared on a stainless steel (St) surface, and the resulting surface subjected to enzymatic cleaning with an electric potential being applied to the St plate. Trypsin, alpha-chymotrypsin, and thermolysin were used as model proteases. The amounts of protein remaining on the plate before and during the cleaning process were measured by means of a reflection absorption technique using Fourier transform infrared spectroscopy. In the case for BSA fouling, the cleaning efficiency of the protease tended to increase at more negative applied potentials. Whereas, there was an optimum applied potential for removing the lysozyme fouling. Atomic force microscopy analyses indicated that applying an adequate range of electric potential enhanced the enzymatic removal of protein fouling inside scratches on the St plate surface. These findings suggest the existence of two modes of electrostatic interactions for the external electric field, one with protease molecules and the other with digested fragments of the fouling protein. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfb.2017.07.074

Web of Science

researchmap

Characteristics of proteinaceous additives in stabilizing enzymes during freeze-thawing and -drying 査読

Takanori Shimizu, Tamayo Korehisa, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 81 ( 4 ) 687 - 697 2017年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS LTD

Protein-stabilizing characteristics of sixteen proteins during freeze-thawing and freeze-drying were investigated. Five enzymes, each with different instabilities against freezing and dehydration, were employed as the protein to be stabilized. Proteinaceous additives generally resulted in greater enzyme stabilization during freeze-thawing than sugars while the degree of stabilization for basic lysozyme and protamine were inferior to that of neutral and acidic proteins. Freeze-drying-induced inactivation of enzyme was also reduced by the presence of a proteinaceous additive, the extent of which was lower than that for a sugar. In both freeze thawing and freeze drying, the enzymes stabilization by the proteinaceous additive increased with increasing additive concentration. The enhancement of enzyme inactivation caused by pH change was also reduced in the presence of proteinaceous additives. The combined use of a sugar such as sucrose and dextran tended to increase the stabilizing effect of the proteinaceous additive.

DOI： 10.1080/09168451.2016.1274637

Web of Science

researchmap

Surfactant-Free Solid Dispersions of Hydrophobic Drugs in an Amorphous Sugar Matrix Dried from an Organic Solvent 査読

Koji Takeda, Yuto Gotoda, Daichi Hirota, Fumihiro Hidaka, Tomo Sato, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

MOLECULAR PHARMACEUTICS 14 ( 3 ) 791 - 798 2017年3月

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

The technique for homogeneously dispersing hydrophobic drugs in a water-soluble solid matrix (solid dispersion) is a subject that has been extensively investigated in the pharmaceutical industry. Herein, a novel technique for dispersing a solid, without the need to use a surfactant, is reported. A freeze-dried amorphous sugar sample was dissolved in an organic solvent, which contained a soluble model hydrophobic component. The suspension of the sugar and the model hydrophobic component was vacuum foam dried to give a solid powder. Four types of sugars and methanol were used as representative sugars and the organic medium. Four model drugs (indomethacin, ibuprofen, gliclazide, and nifedipine) were employed. Differential scanning calorimetry analyses indicated that the sugar and model drug (100:1) did not undergo segregation during the drying process. The dissolution of the hydrophobic drugs in water from the solid dispersion was then evaluated, and the results indicated that the C-max and AUC(0-60) (min) of the hydrophobic drug in water were increased when the surfactant-free solid dispersion was used. Palatinose and/or alpha-maltose were superior to the other tested carbohydrates in increasing C-max and AUC(0-60 min), for all tested model drugs, and the model drug with a lower water solubility tended to exhibit a greater extent of over-dissolution.

DOI： 10.1021/acs.molpharmaceut.6b01048

Web of Science

researchmap

Adsorption of lysozyme on base metal surfaces in the presence of an external electric potential. 査読

Ei Ei H, Nakama Y, Tanaka H, Imanaka H, Ishida N, Imamura K

Colloids and surfaces. B, Biointerfaces 147 9 - 16 2016年11月

Molecular design of proteinaceous cushion for sensitive biomolecular interaction detection system 査読

Imanaka Hiroyuki, Dare Koki, Imamura Koreyoshi

NEW BIOTECHNOLOGY 33 S72 2016年7月

Surfactant-free solid dispersion of fat-soluble flavour in an amorphous sugar matrix 査読

Tomo Satoh, Fumihiro Hidaka, Kento Miyake, Natsuki Yoshiyama, Koji Takeda, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

FOOD CHEMISTRY 197 1136 - 1142 2016年4月

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

A solid dispersion technique to homogeneously disperse hydrophobic ingredients in a water-soluble solid without using surfactant was examined as follows: first, freeze-dried amorphous sugar was dissolved in an organic medium that contained a soluble model hydrophobic component. Second, the mixed solution of sugar and the model hydrophobic component was vacuum dried into a solid (solid dispersion). Methanol and six fat-soluble flavours, including cinnamaldehyde, were used as organic media and model hydrophobic components. The retention of flavours in the solid dispersion during drying and storage under vacuum was evaluated. The amorphised disaccharides dissolved in methanol up to 100 mg/mL, even temporarily (20 s to 10 days) and could be solidified without any evidence of crystallisation and segregation from flavour. The solid dispersion, prepared using a-maltose usually showed 65-95% flavour retention during drying (and storage for cinnamaldehyde), whereas >= 50% of the flavour was lost when the flavour was O/W emulsified with a surfactant and then freeze-dried with sugar. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodchem.2015.11.097

Web of Science

researchmap

Nanostructures of 3-aminopropyltriethoxysilane created on flat substrate by combining colloid lithography and vapor deposition 査読

Naoyuki Ishida, Ryohei Nishihara, Hiroyuki Imanaka, Koreyoshi Imamura

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 495 39 - 45 2016年4月

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

The creation of patterned structures with micro/nano-scale lengths on flat surfaces has recently been emerged as an important technique in various fields. In this report, we present a simple method to create nanopatterns of 3-aminopropyltriethoxysilane (APS) on glass substrates by the combination of colloid lithography and vapor deposition. When deposition was conducted at room temperature under natural humidity, an array of nanorings was formed on the substrate by the condensation of APS vapor on the water bridges remaining under the particles. By varying only the deposition temperature, the structure of the ordered arrays could easily be transformed: nanorings were converted to honeycomb and dot like structures by increasing temperature. This transformation proposedly occurred by the condensation and polymerization of APS vapor through the deformed particles of the colloidal monolayer. We also fabricated a patterned polymer brush array and a pore array using the obtained APS nanopattern as a template. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfa.2016.01.047

Web of Science

researchmap

The Use of a Proteinaceous “Cushion” with a Polystyrene-Binding Peptide Tag to Control the Orientation and Function of a Target Peptide Adsorbed to a Hydrophilic Polystyrene Surface 査読

Hiroyuki Imanaka, Daisuke Yamadzumi, Keisuke Yanagita, Naoyuki Ishida, Kazuhiro Nakanishi an, Koreyoshi Imamura

Biotechnology Progress 32 ( 2 ) 527 - 534 2016年3月

クッションタンパク質の分子デザインによるバイオ分子間相互作用の高感度化

今中洋行, 伊達弘輝, 的場晴香, 石田尚之, 今村維克

表面科学学術講演会要旨集 36 37 - 37 2016年

記述言語：日本語出版者・発行元：公益社団法人日本表面科学会

ELISA，SPRやQCMなどのバイオ分子間相互作用検出系における基板上へのリガンド分子の固定化について，基板親和性ペプチド連結による固定化配向制御ならびにリガンド分子と基板との直接的な相互作用を緩和するクッションタンパク質を用いた機能維持を試みた．そして，クッションタンパク質の様々な分子デザインにより，ペプチド-タンパク質間あるいはタンパク質-タンパク質間相互作用検出を顕著に高感度化できた．

DOI： 10.14886/sssj2008.36.0_37

CiNii Article

researchmap

Effect of surface hydrophobicity on short-range hydrophobic attraction between silanated silica surfaces 査読

Soga Yuhei, Imanaka Hiroyuki, Imamura Koreyoshi, Ishida Naoyuki

ADVANCED POWDER TECHNOLOGY 26 ( 6 ) 1729 - 1733 2015年11月

Inhibitory effects of additives and heat treatment on the crystallization of freeze-dried sugar 査読

Kohshi Kinugawa, Mitsunori Kinuhata, Ryo Kagotani, Hiroyuki Imanaka, Naoyuki Ishida, Mizuki Kitamatsu, Kazuhiro Nakanishi, Koreyoshi Imamura

JOURNAL OF FOOD ENGINEERING 155 37 - 44 2015年6月

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

An amorphous matrix of a sugar is frequently used as a bulk-forming and stabilizing agent in the food industry but tends to crystallize as the result of water uptake and increase in temperature. Additives and methods used to inhibit the crystallization of amorphous sugar (sucrose) were screened in this study. Freeze-dried amorphous sucrose containing 0.5-5 wt% of additive, including salts, different types of sugars, and polymers, the crystallization temperature (T-cry) and isothermal crystallization characteristics were examined. Certain types of salts markedly increased the Tcry and prolonged the induction period for crystal nucleation. The use of 1 wt% MgCl2 was particularly effective in inhibiting sugar crystallization. The heat treatment of crystalline sucrose under appropriate conditions was also found to result in diminished sucrose crystallization. MALDI-TOF mass spectra of the heat-treated sucrose suggested that sucrose derivatives containing multiple pyranose groups were formed, which would closely relate to the crystallization inhibition. Finally, the protein stabilizing effects of the matrices were evaluated. The results indicated that both the addition of additives and the heat treatment resulted in an improvement of the protein stabilizing effect of amorphous sugar matrix, compared to that of sucrose alone. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jfoodeng.2015.01.016

Web of Science

researchmap

Influence of sugar surfactant structure on the encapsulation of oil droplets in an amorphous sugar matrix during freeze-drying 査読

Shota Nakayama, Yoshifumi Kimura, Sayuri Miki, Jun Oshitani, Takashi Kobayashi, Shuji Adachi, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Hiroko Tada, Kazuhiro Nakanishi, Koreyoshi Imamura

FOOD RESEARCH INTERNATIONAL 70 143 - 149 2015年4月

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

The encapsulation of O/W emulsion droplets in a freeze-dried amorphous sugar matrix was investigated, focusing on the impact of the molecular structure of the emulsifying surfactant. O/W emulsions, containing various surfactants, were freeze-dried in the presence of a sugar. Thirty types of surfactants, including eighteen different sugar surfactants and ten types of commercially available sugar ester mixtures, were used. Linoleic acid methyl ester and trehalose were used as the oil phase and sugar. The amounts of oil droplets encapsulated in freeze-dried amorphous sugar matrix were analyzed by Fourier transform Infrared spectroscopy. Sugar surfactants were generally superior to the other classes of surfactants for oil droplet encapsulation during freeze-drying, and there was the optimum alkyl chain length of the sugar surfactant. Sugar esters generally exhibited greater oil encapsulation than sugar ethers. Larger sugar head group appeared to result in better encapsulation in the case of sugar esters, but the opposite tendency was found for sugar ethers. A limited combination of sugar surfactants (15% sucrose mono- and 85% di-stearate) resulted in the maximum oil droplet encapsulation efficiency although these surfactants are individually quite poor in the encapsulation and other tested combinations did not improve the encapsulation efficiency relative to their individual effectiveness. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodres.2015.02.003

Web of Science

researchmap

Polymorphobacter multimanifer gen. nov., sp nova, a polymorphic bacterium isolated from antarctic white rock 査読

Wakao Fukuda, Yohzo Chino, Shigeo Araki, Yuka Kondo, Hiroyuki Imanaka, Tamotsu Kanai, Haruyuki Atomi, Tadayuki Imanaka

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 64 ( 6 ) 2034 - 2040 2014年6月

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

A Gram-stain-negative, non-spore-forming, aerobic, oligotrophic bacterium (strain 262-7(T)) was isolated from a crack of white rock collected in the Skallen region of Antarctica. Strain 262-7(T) grew at temperatures between -4 and 30 degrees C, with optimal growth at 25 degrees C. The pH range for growth was between pH 6.0 and 9.0, with optimal growth at approximately pH 7.0. The NaCl concentration range allowing growth was between 0.0 and 1.0%, with an optimum of 0.5%. Strain 262-7(T) showed an unprecedented range of morphological diversity in response to growth conditions. Cells grown in liquid medium were circular or ovoid with smooth surfaces in the lag phase. In the exponential phase, ovoid cells With short projections were observed. Cells in the stationary phase possessed long tentacle-like projections intertwined intricately. By contrast, cells grown on agar plate medium or in liquid media containing organic compounds at low concentration exhibited short- and long-rod-shaped morphology. These projections and morphological variations clearly differ from those of previously described bacteria. Ubiquinone 10 was the major respiratory quinone. The major fatty acids were C-17:1 omega 6c (28.2%), C-16:1 omega 7c (22.6%), C-18:1 omega 7c (12.9%) and C(15:0)2-OH (12.3%). The G+C content of genomic DNA was 68.0 mol%. Carotenoids were detected from the cells. Comparative analyses of 16S rRNA gene sequences indicated that strain 262-7(T) belongs to the family Sphingomonadaceae, and that 262-7(T) should be distinguished from known genera in the family Sphingomonadaceae. According to the phylogenetic position, physiological characteristics and unique morphology variations, strain 262-7(T) should be classified as a representative of a novel genus of the family Sphingomonadaceae. Here, a novel genus and species with the name Polymorphobacter multimanifer gen. nov., sp. nov. is proposed (type strain 262-7(T)=JCM 18140(T)=ATCC BAA-2413(T)). The novel species was named after its morphological diversity and formation of unique projections.

DOI： 10.1099/ijs.0.050005-0

Web of Science

researchmap

Characteristics of Sugar Surfactants in Stabilizing Proteins During Freeze?Thawing and Freeze‐Drying 査読

Koreyoshi Imamura, Katsuyuki Murai, Tamayo Korehisa, Noriyuki Shimizu, Ryo Yamahira, Tsutashi, Matsuura, Hiroko Tada, Hiroyuki Imanaka, Naoyuki Ishida, Kazuhiro Nakanishi

Journal of Pharmaceutical Sciences 103 ( 6 ) 1628 - 1637 2014年6月

Effect of Surface Hydrophobicity on Short-Range Hydrophobic Attraction between Silanated Silica Surfaces 査読

Yuuhei Soga, Hiroyuki Imanaka, Koreyoshi Imamura, Naoyuki Ishida

Advanced Powder Technology 51 ( 5 ) 343 - 348 2014年

2P078 新規金表面親和性ペプチドの同定及びタンパク質固定化への応用(01D. 蛋白質:機能,ポスター,第52回日本生物物理学会年会(2014年度))

Shigemori Yojiro, Yoshida Kaori, Imamura Koreyoshi, Takahashi Yuichiro, Imanaka Hiroyuki

生物物理 54 ( 1 ) S207 2014年

2P085 CS複合体形成をモデルとした高感度ペプチド-タンパク質間相互作用検出系のデザイン(01F. 蛋白質:蛋白質工学/進化工学,ポスター,第52回日本生物物理学会年会(2014年度))

Matsushita Runa, Ishida Naoyuki, Imamura Koreyoshi, Imanaka Hiroyuki

生物物理 54 ( 1 ) S209 2014年

Improving the physical stability of freeze-dried amorphous sugar matrices by compression at several hundreds MPa 査読

Ryo Kagotani, Kohshi Kinugawa, Mayo Nomura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

JOURNAL OF PHARMACEUTICAL SCIENCES 102 ( 7 ) 2187 - 2197 2013年7月

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

Amorphous matrices, composed of sugars, are markedly plasticized by moisture uptake, which results in physical instability. Our previous studies, in the compression pressure range 443 MPa, indicated that when a matrix is compressed, the amount of sorbed water at given relative humidities (RHs) decreases, whereas the glass transition temperature (Tg) remains constant. Herein, the effect of higher compression pressures than those used previously was explored to investigate the feasibility of using compression to improve the physical stability of amorphous sugar matrix against water uptake and subsequent collapse. Amorphous sugar samples were prepared by freeze-drying and then compressed at 0-665 MPa, followed by rehumidification at given RHs. The physical stability of the amorphous sugar sample was evaluated by measuring Tg and crystallization temperature (Tcry). The amounts of sorbed water, different in the interaction state, were determined using an FTIR technique. It was found that the compression at pressures of 443 MPa decreased the amount of sorbed water, which is a major factor in plasticization and crystallization, and thus markedly increased the Tg and Tcry relative to that for the uncompressed sample. Hence, the compression at several hundreds MPa appears to be feasible for improving the physical stability of amorphous sugar matrix. (c) 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2187-2197, 2013

DOI： 10.1002/jps.23568

Web of Science

researchmap

Characteristics of amorphous matrices composed of different types of sugars in encapsulating emulsion oil droplets during freeze-drying 査読

Koreyoshi Imamura, Yoshifumi Kimura, Shota Nakayama, Miki Sayuri, Seiji Ogawa, Tatsuya Hoshino, Jun Oshitani, Takashi Kobayashi, Shuji Adachi, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Kazuhiro Nakanishi

FOOD RESEARCH INTERNATIONAL 51 ( 1 ) 201 - 207 2013年4月

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

The encapsulation of emulsion oil droplets by amorphous sugar matrices, formed by freeze-drying, was investigated, with a focus on the influence of the type of sugar. An oil-in-water emulsion, comprised of linoleic acid methyl ester (LME) and sucrose monolaurate (SML) as an oil phase and surfactant, respectively, were freeze-dried in the presence of different types of sugars. LME-droplet encapsulation during and after freeze-drying were evaluated by FTIR analysis. The loss of LME largely occurred in the early stage of freeze-drying. The size distribution of the encapsulated LME droplets remained unchanged before and after freeze-drying in most cases. The encapsulated fractions of LME droplets could be correlated with the glass transition temperature of the sugars in the fully hydrated state (T-g*), and the existence of an optimum T-g* value for the sugar matrix was predicted. The encapsulation ability of an amorphous sugar matrix was maximized when mono- and polysaccharide were combined so as to give a value for T-g* of approximately -50 degrees C, although, individually, mono- and polysaccharides were quite poor for oil droplet encapsulation. These findings suggest that the structural flexibility of the amorphous sugar matrix is a major determinant in oil droplet encapsulation by an amorphous sugar matrix during freeze-drying. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodres.2012.12.010

Web of Science

researchmap

The Discoidin Domain of Bacillus circulans β-Galactosidase Plays an Essential Role in Repressing Galactooligosaccharide Production 査読

Jingyuan Song, Hiroyuki Imanaka, Koreyoshi Imamura, Masashi Minoda, Shotaro Yamaguchi an, Kazuhiro Nakanishi

Bioscience Biotechnology and Biochemistry 77 ( 1 ) 73 - 79 2013年1月

　前のページ - 次のページ　

<今中 洋行>

論文 - 今中 洋行

<今中　洋行>

論文 - 今中　洋行