研究者詳細 - 石川　健治

論文 - 石川　健治

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Impact of helium pressure in arc plasma synthesis on crystallinity of single-walled carbon nanotubes 査読有り

Ando, A; Takeda, K; Ohta, T; Ito, M; Hiramatsu, M; Ishikawa, K; Kondo, H; Sekine, M; Suzuki, T; Inoue, S; Ando, Y; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018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：Japanese Journal of Applied Physics

Single-walled carbon nanotubes (SWNTs) were synthesized with a high growth rate by an arc plasma method employing the electrodes made from a Ni–Y mixture catalyst. In a previous study, it was reported that the monitoring of high-crystallinity SWNT growth enabled the evaluation of the results of the optical emission spectroscopy (OES) of C2, Ni, and Y. Here, the impact of helium pressure of arc plasma on the high crystallinity of SWNTs was determined by considering the high intensity ratios of catalytic metals over C2 emissions at low helium pressures in the arc plasma.

DOI： 10.7567/JJAP.57.06JF01

Effects of gas residence time of CH<sub>4</sub>/H<sub>2</sub> on sp<SUP>2</SUP> fraction of amorphous carbon films and dissociated methyl density during radical-injection plasma-enhanced chemical vapor deposition 査読有り

Sugiura, H; Jia, LY; Kondo, H; Ishikawa, K; Tsutsumi, T; Hayashi, T; Takeda, K; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018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：Japanese Journal of Applied Physics

Quadruple mass spectrometric measurements of CH3 density during radical-injection plasma-enhanced chemical vapor deposition to consider the sp2 fraction of amorphous carbon (a-C) films were performed. The sp2 fraction of the a-C films reached a minimum of 46%, where the CH3 density was maximum for a residence time of 6 ms. The sp2 fraction of the a-C films was tailored with the gaseous phase CH3 density during the deposition. This knowledge is useful for understanding the formation mechanism of bonding structures in the a-C films, which enables the precise control of their electronic properties.

DOI： 10.7567/JJAP.57.06JE03

Dry Process FOREWORD 査読有り

Karahashi, K; Kinoshita, K; Higashi, S; Ishikawa, K; Ishijima, T; Kuboi, N

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 6 ) 2018年6月

Nanographene synthesized in triple-phase plasmas as a highly durable support of catalysts for polymer electrolyte fuel cells 査読有り

Amano, T; Kondo, H; Takeda, K; Ishikawa, K; Hiramatsu, M; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 4 ) 2018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：Japanese Journal of Applied Physics

Nanographene was synthesized in triple-phase plasmas comprising a gaseous phase, a gas-liquid boundary layer, and an in-liquid phase using a setup in which one electrode was placed in the gaseous phase while the other was immersed in the liquid phase. The triple-phase plasmas were generated using a pure alcohol, such as ethanol, 1-propanol, or 1-butanol, by applying a high voltage to a pair of electrodes made of copper or graphite. The nanographene synthesized using ethanol had high durability and thus could serve as a catalyst support in polymer electrolyte fuel cells (PEFCs). The PEFCs exhibited low degradation rates in the high-potential cycle test of a half-cell, as a result of which, a loss of only 10% was observed in the effective electrochemical surface area of Pt, even after 10,000 cycles.

DOI： 10.7567/JJAP.57.045101

Oxygen reduction reaction properties of nitrogen-incorporated nanographenes synthesized using in-liquid plasma from mixture of ethanol and iron phthalocyanine 査読有り

Amano, T; Kondo, H; Takeda, K; Ishikawa, K; Hiramatsu, M; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 4 ) 2018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：Japanese Journal of Applied Physics

Nanographenes were synthesized using in-liquid plasma from a mixture of iron phthalocyanine and ethanol. In a previous study, micrometer-scale flakes with nitrogen incorporation were obtained. A nonprecious metal catalytic activity was observed with 3.13 electrons in an oxygen reduction reaction under an acidic solute condition. Large-surface-area, high-graphene-crystallinity, and iron-carbon-bonding sites were found owing to a high catalytic activity in Fe-N/nanographene.

DOI： 10.7567/JJAP.57.040303

Cytotoxicity of cancer HeLa cells sensitivity to normal MCF10A cells in cultivations with cell culture medium treated by microwave-excited atmospheric pressure plasmas 査読有り

Takahashi, Y; Taki, Y; Takeda, K; Hashizume, H; Tanaka, H; Ishikawa, K; Hori, M

JOURNAL OF PHYSICS D-APPLIED PHYSICS 51 巻 ( 11 ) 2018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：Journal of Physics D: Applied Physics

Cytotoxic effects of human epithelial carcinoma HeLa cells sensitivity to human mammary epithelial MCF10A cells appeared in incubation with the plasma-activated medium (PAM), where the cell culture media were irradiated with the hollow-shaped contact of a continuously discharged plasma that was sustained by application of a microwave power under Ar gas flow at atmospheric pressure. The discharged plasma had an electron density of 7

DOI： 10.1088/1361-6463/aaab09

Free radical generation by non-equilibrium atmospheric pressure plasma in alcohol-water mixtures: an EPR-spin trapping study 査読有り

Uchiyama, H; Ishikawa, K; Zhao, QL; Andocs, G; Nojima, N; Takeda, K; Krishna, MC; Ishijima, T; Matsuya, Y; Hori, M; Noguchi, K; Kondo, T

JOURNAL OF PHYSICS D-APPLIED PHYSICS 51 巻 ( 9 ) 2018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：Journal of Physics D: Applied Physics

Free radical species in aqueous solution - various alcohol-water reaction mixtures - by exposure to non-equilibrium cold atmospheric pressure Ar plasma (CAP), were monitored using electron paramagnetic resonance spin-trapping techniques with 3, 5-dibromo-4-nitrosobenzene sulfonate as a water soluble nitroso spin trap. The major radical species were formed by H-abstraction from alcohol molecules due to •OH radicals. In the ethanol-water mixture •CH2CH2OH produced by H abstraction from CH3 group of the ethanol and •CH3 radicals were detected. The latter was due to the decomposition of unstable CH3•CHOH to form the •CH3 radicals and the stable formaldehyde by C-C bond fission. These intermediates are similar to those observed by reaction with •OH radicals generation in the H2O2-UV photolysis of the reaction mixtures. The evidence of •CH3 radical formation in the pyrolytic decomposition of the reaction mixtures by exposure to ultrasound or in methane irradiated with microwave plasma have been reported previously. However, the pyrolytic •CH3 radicals were not found in both plasma and H2O2-UV photolysis condition. These results suggests that free radicals produced by Ar-CAP are most likely due to the reaction between abundant •OH radicals and alcohol molecules.

DOI： 10.1088/1361-6463/aaa885

Facile fabrication of a poly(ethylene terephthalate) membrane filter with precise arrangement of through-holes 査読有り

Kihara, N; Odaka, H; Kuboyama, D; Onoshima, D; Ishikawa, K; Baba, Y; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 3 ) 2018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：Japanese Journal of Applied Physics

Although membrane filters are indispensable in biochemical analysis fields, most methods for through-hole fabrication are complex and inefficient. We developed a simple method of fabricating poly(ethylene terephthalate) (PET) membrane filters with a precise arrangement of through-holes for the isolation of circulating tumor cells (CTCs) based on their size. By photolithography and dry etching, highly packed 380,000 through-holes with a diameter of 7 μm were able to cover a whole area with a diameter of 13 mm. Device fabrication for the size-based capture of rare cells in blood such as CTCs is realized in this study.

DOI： 10.7567/JJAP.57.037001

Reduced HeLa cell viability in methionine-containing cell culture medium irradiated with microwave-excited atmospheric-pressure plasma 査読有り

Takahashi, Y; Taki, Y; Takeda, K; Hashizume, H; Tanaka, H; Ishikawa, K; Hori, M

PLASMA PROCESSES AND POLYMERS 15 巻 ( 3 ) 2018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：Plasma Processes and Polymers

The mechanism underlying the death of cancer cells incubated in plasma-activated medium (PAM) prepared by irradiation of culture medium with atmospheric-pressure plasma is revealed by analyzing changes in the culture medium composition using liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance spectroscopy. The concentration of the essential amino acid methionine declined in microwave-excited plasma-irradiated medium, whereas, that of methionine sulfoxide increased due to oxidation of methionine. The decrease in methionine concentration in the cell culture medium rather than the increase in methionine sulfoxide leads to the decline in the survival rate of HeLa cells incubated in PAM. These results provide useful insights into the mechanism of selective cancer cell death in PAM.

DOI： 10.1002/ppap.201700200

Nanographene synthesis employing in-liquid plasmas with alcohols or hydrocarbons 査読有り

Ando, A; Ishikawa, K; Kondo, H; Tsutsumi, T; Takeda, K; Ohta, T; Ito, M; Hiramatsu, M; Sekine, M; Hori, M

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 2 ) 2018年2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：Japanese Journal of Applied Physics

Graphenes of nanometer-scale grain size (nanographenes) were synthesized using in-liquid plasmas with alcohols or hydrocarbons. This method of nanographene synthesis showed a trade-off relationship between crystallinity and synthesis rate. The high crystallinity of nanographenes synthesized with alcohols was evaluated from the small full width at half maxima (FWHM) of the G band in Raman scattering spectra. On the other hand, in the case of using hydrocarbons such as n-hexane and benzene, a significantly high synthesis rate was obtained but the crystallinity of nanographenes was low. It was found that hydroxyl groups and oxygen atoms of liquid sources play important roles in determining the crystallinity of synthesized nanographenes.

DOI： 10.7567/JJAP.57.026201

Advanced Plasma Science and Its Applications for Nitrides and Nanomaterials FOREWORD 査読有り

Naritsuka, S; Miyazaki, S; Fujiwara, Y; Hiramatsu, M; Inoue, Y; Ishikawa, K; Ito, M; Itoh, T; Kasu, M; Miyake, H; Sasaki, M; Shirafuji, T; Suda, Y

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 1 ) 2018年1月

Electron impact ionization of perfluoro-methyl-vinyl-ether C<sub>3</sub>F<sub>6</sub>O 査読有り

Kondo, Y; Ishikawa, K; Hayashi, T; Sekine, M; Hori, M

PLASMA SOURCES SCIENCE & TECHNOLOGY 27 巻 ( 1 ) 2018年1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：Plasma Sources Science and Technology

A mechanism for the electron impact ionization of perfluoro-methyl-vinyl-ether (CF3OCF=CF2) molecules was studied theoretically using quantum chemical calculations. Positive and negative C2F3O- ions were abundantly generated, as supported by quadrupole mass spectrometry observations. The vinyl ethers easily dissociated at the ether bond due to polarization of the charge on the bridging oxygen atom. Consequently, perfluoro-vinyl-ethers form abundant ions via ether-specific pathways.

DOI： 10.1088/1361-6595/aaa22e

Selective production of reactive oxygen and nitrogen species in the plasma-treated water by using a nonthermal high-frequency plasma jet 査読有り

Uchida, G; Takenaka, K; Takeda, K; Ishikawa, K; Hori, M; Setsuhara, Y

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 1 ) 2018年1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：Japanese Journal of Applied Physics

We present the control of H2O2 and NO2- productions in deionized water by using a high-frequency plasma jet driven by a 60 MHz voltage. In the gas phase, the high-frequency plasma jet has a high O (3P) atom density of 8 × 1014 cm-3, which is two orders of magnitude higher than that of the low-frequency plasma jet driven by a 5 kHz voltage. Concerning the production of reactive oxygen and nitrogen species in the liquid phase, with the direct contact of the plasma jet to the liquid surface, the H2O2 concentration is higher than the NO2- concentration. On the other hand, without the observable contact of the high-frequency plasm jet with high plasma density to the liquid surface, the NO2- concentration increases with the flow rate of N2(20%)O2(80%) gas added to the Ar discharge gas and becomes more dominant compared with H2O2 in the plasma-treated water. H2O2 and NO2- could be selectively produced in the plasma-treated water by using a nonthermal high-frequency plasma jet, which is a promising tool for biomedical applications.

DOI： 10.7567/JJAP.57.0102B4

Rapid growth of micron-sized graphene flakes using in-liquid plasma employing iron phthalocyanine-added ethanol 査読有り

Amano, T; Kondo, H; Ishikawa, K; Tsutsumi, T; Takeda, K; Hiramatsu, M; Sekine, M; Hori, M

APPLIED PHYSICS EXPRESS 11 巻 ( 1 ) 2018年1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：Applied Physics Express

Giant graphene flakes on the micron scale were synthesized and grown in plasmas in liquid-phase pure ethanol with added iron phthalocyanine (FePc) in a solvent. At atmospheric pressure, plasmas were generated in the gas phase filled with Ar and in the liquid phases comprising bubbles and liquid solutions. In the mixture of FePc in ethanol, nanographene sheets aggregated to form giant graphene flakes, as confirmed by the D, G, and 2D bands in the corresponding Raman spectra. Therefore, a bottom-up approach of graphite synthesis from pure ethanol with additives and a catalyst was realized by in-liquid plasma processing.

DOI： 10.7567/APEX.11.015102

Plasma-activated medium (PAM) kills human cancer-initiating cells 査読有り Open Access

Ikeda, J; Tanaka, H; Ishikawa, K; Sakakita, H; Ikehara, Y; Hori, M

PATHOLOGY INTERNATIONAL 68 巻 ( 1 ) 頁： 23 - 30 2018年1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：Pathology International

Medical non-thermal plasma (NTP) treatments for various types of cancers have been reported. Cells with tumorigenic potential (cancer-initiating cells; CICs) are few in number in many types of tumors. CICs efficiently eliminate anti-cancer chemicals and exhibit high-level aldehyde dehydrogenase (ALDH) activity. We previously examined the effects of direct irradiation via NTP on cancer cells; even though we targeted CICs expressing high levels of ALDH, such treatment affected both non-CICs and CICs. Recent studies have shown that plasma-activated medium (PAM) (culture medium irradiated by NTP) selectively induces apoptotic death of cancer but not normal cells. Therefore, we explored the anti-cancer effects of PAM on CICs among endometrioid carcinoma and gastric cancer cells. PAM reduced the viability of cells expressing both low and high levels of ALDH. Combined PAM/cisplatin appeared to kill cancer cells more efficiently than did PAM or cisplatin alone. In a mouse tumor xenograft model, PAM exerted an anti-cancer effect on CICs. Thus, our results suggest that PAM effectively kills both non-CICs and CICs, as does NTP. Therefore, PAM may be a useful new anti-cancer therapy, targeting various cancer cells including CICs.

DOI： 10.1111/pin.12617

Cell Deposition Microchip with Micropipette Control over Liquid Interface Motion. 査読有り

Onoshima D, Hattori Y, Yukawa H, Ishikawa K, Hori M, Baba Y

Cell medicine 10 巻頁： 2155179017733152 2018年

Isotropic atomic level etching of tungsten using formation and desorption of tungsten fluoride 査読有り

Shinoda, K; Miyoshi, N; Kobayashi, H; Hanaoka, Y; Kawamura, K; Izawa, M; Ishikawa, K; Hori, M

ADVANCED ETCH TECHNOLOGY FOR NANOPATTERNING VII 10589 巻 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Proceedings of SPIE - The International Society for Optical Engineering

A selective, rapid thermal-cyclic atomic-level etching (ALE) of tungsten is developed. The first step of this process is exposing the surface of tungsten with hydrofluorocarbon plasma at -22°C to form a tungsten fluoride-based surface modified layer on the tungsten surface. The second step is rapid thermal annealing with infrared (IR) irradiation to remove the surface modified layer. Tungsten 4f peaks and a fluorine 1s peak, which were assigned to tungsten fluoride, were observed by in-situ x-ray photoelectron spectroscopy immediately after plasma exposure. The peaks that originated from tungsten fluoride disappeared after the samples were annealed. Cyclic etching tests were carried out by repeating plasma exposure and IR irradiation with a 300-mm ALE tool. Films of tungsten, TiN, and SiO2 were used as sample materials. The amount of etched tungsten increased as the number of cycle repetitions increased. The etched amount per cycle for tungsten was 0.8 nm. In comparison, etching of TiN and SiO2 was not detected. Conformal etching profiles of patterned samples after 60 cycles were obtained. Furthermore, the etched amount per cycle showed saturation behavior with regard to plasma exposure time. Selective, rapid thermal cyclic ALE of tungsten was thus successfully demonstrated.

DOI： 10.1117/12.2297241

Glioblastoma Cell Lines Display Different Sensitivities to Plasma-Activated Medium 査読有り

Tanaka H., Mizuno M., Ishikawa K., Takeda K., Hashizume H., Nakamura K., Utsumi F., Kajiyama H., Okazaki Y., Toyokuni S., Akiyama S., Maruyama S., Kikkawa F., Hori M.

IEEE Transactions on Radiation and Plasma Medical Sciences 2 巻 ( 2 ) 頁： 99 - 102 2018年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Radiation and Plasma Medical Sciences

Plasma-activated medium (PAM) is a novel chemotherapy that induces reactive oxygen species (ROS) and cell death in a wide range of cancer cell types, suggesting that PAM may be a promising therapeutic option for cancer treatment. However, dose response experiments suggest that PAM sensitivity is cell line specific. We examined the sensitivities of three glioblastoma cell lines to PAM, and found a wide variation in cell killing that was linked to differences in PAM induced ROS and apoptosis. These results indicate that the PAM sensitivity of glioblastoma cells, and potentially cancer cells more generally, is heterogeneous and likely to be dependent on the regulation of apoptosis and antioxidant pathways in target cells.

DOI： 10.1109/trpms.2017.2721973

Oncogene mutation analysis of circulating tumor cells using single-cell membrane separation and DNA amplification 査読有り

Onoshima D., Kuboyama D., Kihara N., Tanaka H., Hase T., Yukawa H., Ishikawa K., Odaka H., Hasegawa Y., Hori M., Baba Y.

22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018 3 巻頁： 1291 - 1293 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018

We present a study of genomic profiling for circulating tumor cells (CTCs) using a blood microfiltration system. DNA amplification of CTCs was performed with a microfilter for single cancer cells in a clinical setting. This strategy was successfully used to detect the driver mutations in epidermal growth factor (EGF) receptor oncogenes by quantitative PCR and characterize the dosing effect of molecularly targeted drug for lung cancer.

Exosome isolation toward cancer diagnosis using glass filter with nanoporous structure 査読有り

Aoki K., Yukawa H., Onoshima D., Yamazaki S., Kihara N., Koguchi R., Takahashi K., Odaka H., Ishikawa K., Hori M., Baba Y.

22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018 3 巻頁： 1409 - 1410 2018年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018

We present a study of centrifugal filtration device toward easy-to-use approach of non-invasive liquid biopsy for cancer diagnosis by cell-derived nanoscale vesicles (exosomes). A phase-dispersed glass filter having nanoporous structure was embedded into a spin column to trap exosomes with small centrifuge. This device enabled over 90% exosome isolation from biological samples within 10 minutes.

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