534 results on '"Hikaru Kobayashi"'
Search Results
102. DEVELOPMENT OF DESICCANT AIR CONDITIONING SYSTEM OF ENERGIZATION-REGENERATION TYPE USING CONDUCTIVE POLYMER (PEDOT/PSS)
- Author
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Asuka Iyatomi, Hikaru Kobayashi, and Ryota Hiura
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Environmental Engineering ,Materials science ,0208 environmental biotechnology ,02 engineering and technology ,020801 environmental engineering - Published
- 2018
103. Properties of nanocrystalline Si layers embedded in structure of solar cell
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Stanislav Jurečka, Kentaro Imamura, Hikaru Kobayashi, and Taketoshi Matsumoto
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Materials science ,business.industry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Nanocrystalline material ,0104 chemical sciences ,law.invention ,symbols.namesake ,Semiconductor ,Fourier analysis ,law ,Solar cell ,symbols ,Optoelectronics ,0210 nano-technology ,business ,Silicon solar cell - Abstract
Suppression of spectral reflectance from the surface of solar cell is necessary for achieving a high energy conversion efficiency. We developed a simple method for forming nanocrystalline layers with ultralow reflectance in a broad range of wavelengths. The method is based on metal assisted etching of the silicon surface. In this work, we prepared Si solar cell structures with embedded nanocrystalline layers. The microstructure of embedded layer depends on the etching conditions. We examined the microstructure of the etched layers by a transmission electron microscope and analysed the experimental images by statistical and Fourier methods. The obtained results provide information on the applied treatment operations and can be used to optimize the solar cell forming procedure.
- Published
- 2017
104. Fabrication of Si nanopowder and application to hydrogen generation and photoluminescent material
- Author
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Yuki Kobayashi, Kentaro Imamura, Taketoshi Matsumoto, and Hikaru Kobayashi
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Adsorption ,Materials science ,Photoluminescence ,Fabrication ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,0104 chemical sciences ,Hydrogen production - Abstract
Si nanopowder is fabricated using the simple beads milling method. Fabricated Si nanopowder reacts with water in the neutral pH region between 7 and 9 to generate hydrogen. The hydrogen generation rate greatly increases with pH, while pH does not change after the hydrogen generation reaction. In the case of the reactions of Si nanopowder with strong alkaline solutions (eg pH13.9), 1600 mL hydrogen is generated from 1 g Si nanopowder in a short time (eg 15 min). When Si nanopowder is etched with HF solutions and immersed in ethanol, green photoluminescence (PL) is observed, and it is attributed to band-to-band transition of Si nanopowder. The Si nanopowder without HF etching in hexane shows blue PL. The PL spectra possess peaked structure, and it is attributed to vibronic bands of 9,10-dimethylantracene (DMA) in hexane solutions. The PL intensity is increased by more than 3,000 times by adsorption of DMA on Si nanopowder.
- Published
- 2017
105. Investigation of deep defects in nanocrystalline-Si/Si interfaces using acoustic spectroscopy
- Author
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Peter Bury, Kento Imamura, Hikaru Kobayashi, and Štefan Hardoň
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Materials science ,business.industry ,020209 energy ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,0210 nano-technology ,business ,Nanocrystalline material ,Acoustic spectroscopy - Abstract
A set of structures with nanocrystalline-Si/Si interfaces formed on p-type Si substrate appropriated for photovoltaic application was prepared. The Acoustic DLTS technique based on the acoustoelectric response signal produced by the structure when a longitudinal acoustic wave propagates through the structure was used together with electric characterization to determine deep defects and the role of both individual layers. Several kinds of interface deep centers with activation energies typical for dangling bonds, oxygen participated Si or point defects were observed as well as a particular influence of individual layers on the interface states. The obtained results are analyzed, discussed and subsequently compared.
- Published
- 2017
106. High conversion efficiency of crystalline Si solar cells using black − Si fabricated by SSCT method
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Yuya Onitsuka, Yuya Sakae, Hikaru Kobayashi, and Kentaro Imamura
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Materials science ,business.industry ,Energy conversion efficiency ,Optoelectronics ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,business ,01 natural sciences ,Reflectivity ,Phosphosilicate glass ,0104 chemical sciences - Abstract
We have developed a technology for fabrication of black − Si by use of the surface structure chemical transfer (SSCT) method. The ultralow reflectance below 3% results from formation of a graded porosity structure of a nanocrystalline Si layer formed by the SSCT method. The nanocrystalline Si layer with an extremely large surface area is effectively passivated by deposition of phosphosilicate glass (PSG) followed by heat treatment at 925 ◦C. After PSG passivation, the minority carrier lifetime greatly increases, and the internal quantum efficiency in the short wavelength region is also greatly increased. Using the SSCT method and the PSG passivation method, the high conversion efficiency of 19.7% is achieved.
- Published
- 2017
107. Mechanism of ultra-low reflectance for nanocrystalline Si/crystalline Si structure formed by surface structure chemical transfer method.
- Author
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Kentaro Imamura, Daichi Irishika, and Hikaru Kobayashi
- Subjects
SPECTRAL reflectance ,NANOSILICON ,SURFACE structure ,NANOCRYSTALS spectra ,ELLIPSOMETRY - Abstract
By contact of platinum catalyst with Si wafers immersed in H
2 O2 plus HF solutions, ultra-low reflectance Si surfaces can be produced. The ultra-low reflectance results from the formation of a nanocrystalline Si (nc-Si) layer with ~300 nm thickness. A porosity-graded optical model consisting of 19 sublayers for the nc-Si layer, which is determined from SEM and TEM observations, and the fitting of ellipsometric spectra, is found to well explain the optical properties. The dielectric function of each sublayer is calculated from the Bruggeman effective medium approximation using porosity and the dielectric functions of Si and ~5 nm Si nanocrystals. The reflectance calculated from the optical model shows a good agreement with the experimental result in the wide wavelength region between 300 and 800 nm. This good agreement demonstrates that the ultra-low reflectance of the nc-Si/Si structure results from the refractive index monotonically increasing with the depth. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
108. Rapid Improvement in Jaundice Using Transdermal Isosorbide Tape as a Nitric Oxide Donor in Two Adult Patients with Transplantation-associated Microangiopathy Related to Graft-versus-host Disease.
- Author
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Yuki Hiroshima, Keijiro Sato, Toshimitsu Ueki, Masahiko Sumi, Mayumi Ueno, Naoaki Ichikawa, Hidetoshi Satomi, and Hikaru Kobayashi
- Published
- 2022
- Full Text
- View/download PDF
109. Analysis of five cases of human herpesvirus-6 myelitis among 121 cord blood transplantations
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Hikaru Kobayashi, Toshimitsu Ueki, Yuki Hiroshima, Kenichi Hoshi, Naoaki Ichikawa, Takako Satou, Masahiko Sumi, Takahiro Fukuda, and Masao Ogata
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Adult ,Male ,Foscarnet ,Ganciclovir ,medicine.medical_specialty ,Adolescent ,Fever ,Herpesvirus 6, Human ,Pain ,Myelitis ,Antiviral Agents ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Extrapyramidal disorder ,medicine ,Humans ,Aged ,medicine.diagnostic_test ,Postherpetic neuralgia ,business.industry ,Pruritus ,Magnetic resonance imaging ,Hematology ,Middle Aged ,Allografts ,medicine.disease ,Spinal cord ,Magnetic Resonance Imaging ,Surgery ,Treatment Outcome ,medicine.anatomical_structure ,Autonomic Nervous System Diseases ,Spinal Cord ,030220 oncology & carcinogenesis ,Cord blood ,Female ,Cord Blood Stem Cell Transplantation ,business ,030215 immunology ,medicine.drug - Abstract
Reports of myelitis associated with human herpesvirus-6 (HHV-6) following allogeneic transplantation are rare. Of 121 cases of cord blood transplantation (CBT) performed at Nagano Red Cross Hospital, five cases (4.1%) of HHV-6 myelitis developed at around the time of engraftment. The major symptom identified in all five patients was superficial pain or pruritus linked to segmental levels of the spinal cord. Other identified symptoms were fever or low-grade fever in all five patients, autonomic nerve disorder in four patients, bladder and rectal disturbance in two patients, and extrapyramidal disorder in two patients. These symptoms were experienced primarily 16-39 days after CBT. HHV-6 PCR tests were all positive for cerebrospinal fluid and for plasma. Of the four cases tested by magnetic resonance imaging (MRI), three showed spinal cord abnormality. Antiviral therapy using foscarnet or ganciclovir was effective in every case. Although one case treated from 12 days after onset experienced long-term pain resembling postherpetic neuralgia, symptoms in the four cases were completely relieved after antiviral therapy. In summary, the major symptoms of HHV-6 myelitis were superficial pain linked to segmental levels of the spinal cord. Prognosis may be improved by early initiation of antiviral therapy.
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- 2017
110. Fabrication of Si nanopowder from Si swarf and application to high-capacity and low cost Li-ion batteries
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Katsuya Kimura, Hikaru Kobayashi, Takatoshi Kasukabe, Taketoshi Matsumoto, Takashi Kyotani, and Hirotomo Nishihara
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Materials science ,Fabrication ,Mechanical Engineering ,Metals and Alloys ,Nanotechnology ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Anode ,Chemical engineering ,Mechanics of Materials ,Electrode ,Materials Chemistry ,Crystallite ,0210 nano-technology ,Current density ,Swarf ,Order of magnitude - Abstract
Si nanopowder is expected as a high capacity anode active material for Li-ion batteries (LIBs) due to its superior theoretical capacity of ∼3600 mA h/g, which is approximately one order of magnitude higher than that of conventional graphitic materials. We have succeeded in fabrication of Si nanopowder from Si swarf using the cost-effective beads milling method. The Si nanopowder consists of Si nano-crystals having flake-like shape with two largely different sizes, i.e., several hundred nm sizes and sizes less than 15 nm. The mode diameter of Si crystallites fabricated from Si swarf is 6.3 nm. The performance of the nano-Si electrode for Li ion batteries is greatly improved by carbon-coating on Si nanomaterials and addition of fluoroethylene carbonate (FEC) in an electrolyte solution. By addition of 10–15 wt% FEC, a stable and thin (10–20 nm) solid-electrolyte interphase (SEI) layer is formed on the electrode, and the number of cracks on the electrode surfaces after the 100th cycle greatly decreases. Addition of FEC improves the cyclability and decreases the SEI resistance ( R S E I ) and the charge transfer resistance ( R c t ). However, excess FEC (25 wt%) suppresses free volume expansion of Si nanopowder due to formation of thick SEI, leading to smooth Si surfaces, and resulting in an increase in R c t . Carbon-coating on Si nanopowder greatly improves the cyclability even with the low C/Si ratio of 0.1. In the case of excess carbon-coating, Si nanopowder agglomerates during carbon-coating, which causes peeling-off of a part of carbon-coated Si nanopowder during lithiation, resulting in a decrease of the capacity. The delithiation capacity higher than 1600 mA h/g after the 100th cycle with the current density of 1800 mA/g is achieved by setting the C/Si ratio at 0.1 and the FEC concentration at 10 wt%.
- Published
- 2017
111. Surface nanocrystalline Si structure and its surface passivation for highly efficient black Si solar cells
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Kentaro Imamura, Daichi Irishika, and Hikaru Kobayashi
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Materials science ,Passivation ,Renewable Energy, Sustainability and the Environment ,business.industry ,Energy conversion efficiency ,Black silicon ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Nanocrystalline material ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Optoelectronics ,Quantum efficiency ,Crystalline silicon ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Layer (electronics) ,Phosphosilicate glass - Abstract
19.5% conversion efficiency crystalline silicon (Si) solar cells having simple structure without antireflection coating have been fabricated using the surface structure chemical transfer method which produces a nanocrystalline Si layer simply by contacting catalytic platinum with Si wafers in hydrogen peroxide plus hydrofluoric acid solutions. The reflectivity becomes less than 3% after the surface structure chemical transfer method due to formation of black Si. Deposition of phosphosilicate glass and heat treatment at 925 °C performed for formation of pn-junction effectively passivate the nanocrystalline Si surface. With this phosphosilicate glass passivation plus the hydrogen treatment at 400 °C, the internal quantum efficiency is greatly improved and reaches 81% at a wavelength of 400 nm. Analysis of ellipsometry data shows that incident light with wavelength shorter than 400 nm is almost completely absorbed by the nanocrystalline Si layer. The high internal quantum efficiency for short wavelength light is attributed to effective surface passivation and the nanocrystalline Si layer band-gap energy which decreases with the distance from the top of the network structure of the nanocrystalline Si layer. Copyright © 2017 John Wiley & Sons, Ltd.
- Published
- 2017
112. Multifractal analysis and optical properties of nanostructured silicon layers
- Author
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Kentaro Imamura, Taketoshi Matsumoto, Stanislav Jurečka, and Hikaru Kobayashi
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Materials science ,Silicon ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,symbols.namesake ,Etching (microfabrication) ,Wafer ,Crystalline silicon ,business.industry ,Surfaces and Interfaces ,General Chemistry ,Semiconductor device ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Fourier transform ,chemistry ,symbols ,Optoelectronics ,0210 nano-technology ,business ,Layer (electronics) ,Raman scattering - Abstract
For the optimization of the light trapping in semiconductor devices, especially in the solar cells, microtextured structures are commonly used. Structures with ultralow spectral reflectance were formed on flat and pyramidally textured single crystalline silicon wafers by using of the surface structure chemical transfer method (SSCT). This method is based on effective etching of treated surface in HF solution in contact with a Pt mesh. The structure of the SSCT layer is determined by the etching conditions and influences substantially its optical properties. We studied microstructural properties of the SSCT layers by the SEM and AFM methods and we analyzed obtained morphological information by the multifractal (MF) and Fourier methods. The properties of etched surface layers determine the spectral reflectance and Raman scattering. Exponential fall of the spectral reflectance is caused by the gradient of layer density and enhancement of Raman scattering is related to forming of small particle size fraction during the SSCT etching. Results of MF and Fourier analysis are used in interpretation of the optical properties of formed microtextured structures.
- Published
- 2017
113. Ultrathin SiO 2 layer formed by the nitric acid oxidation of Si (NAOS) method to improve the thermal-SiO 2 /Si interface for crystalline Si solar cells
- Author
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Taketoshi Matsumoto, Daichi Irishika, Hiroki Nakajima, Kentaro Imamura, Hikaru Kobayashi, and Takaaki Nonaka
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010302 applied physics ,Thermal oxidation ,Materials science ,Hydrogen ,Passivation ,Silicon ,Annealing (metallurgy) ,Inorganic chemistry ,Dangling bond ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Carrier lifetime ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Semimetal ,Surfaces, Coatings and Films ,chemistry ,Chemical engineering ,0103 physical sciences ,0210 nano-technology - Abstract
A combination of the nitric acid oxidation of Si (NAOS) method and post-thermal oxidation is found to efficiently passivate the SiO2/n-Si(100) interface. Thermal oxidation at 925 °C and annealing at 450 °C in pure hydrogen atmosphere increases the minority carrier lifetime by three orders of magnitude, and it is attributed to elimination of Si dangling bond interface states. Fabrication of an ultrathin, i.e., 1.1 nm, NAOS SiO2 layer before thermal oxidation and H2 annealing further increases the minority carrier lifetime by 30% from 8.6 to 11.1 ms, and decreased the interface state density by 10% from 6.9 × 109 to 6.3 × 109eV−1 cm−2. After thermal oxidation at 800 °C, the SiO2 layer on the NAOS-SiO2/Si(100) structure is 2.26 nm thick, i.e., 0.24 nm thicker than that on the Si(100) surface, while after thermal oxidation at 925 °C, it is 4.2 nm thick, i.e., 0.4 nm thinner than that on Si(100). The chemical stability results from the higher atomic density of a NAOS SiO2 layer than that of a thermal oxide layer as reported in Ref. [28] (Asuha et al., 2002). Higher minority carrier lifetime in the presence of the NAOS layer indicates that the NAOS-SiO2/Si interface with a low interface state density is preserved after thermal oxidation, which supports out-diffusion oxidation mechanism, by which a thermal oxide layer is formed on the NAOS SiO2 layer.
- Published
- 2017
114. Impact of Human Leukocyte Antigen Allele Mismatch in Unrelated Bone Marrow Transplantation with Reduced-Intensity Conditioning Regimen
- Author
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Naoyuki Uchida, Yasunori Ueda, Shigeo Fuji, Hisayuki Yokoyama, Yoshinobu Kanda, Yuho Najima, Junya Kanda, Sung-Won Kim, Hikaru Kobayashi, Takahiro Fukuda, Hitoshi Ohno, Koji Iwato, Yoshiko Atsuta, Tadakazu Kondo, Yukiyasu Ozawa, Tatsuo Ichinohe, and Tetsuya Eto
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Adult ,Male ,Risk ,Oncology ,medicine.medical_specialty ,Transplantation Conditioning ,Adolescent ,Neutrophils ,medicine.medical_treatment ,Graft vs Host Disease ,Locus (genetics) ,Kaplan-Meier Estimate ,Hematopoietic stem cell transplantation ,Human leukocyte antigen ,Disease-Free Survival ,Leukocyte Count ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,HLA Antigens ,Internal medicine ,Living Donors ,medicine ,Humans ,Allele ,Busulfan ,Melphalan ,Aged ,Bone Marrow Transplantation ,Retrospective Studies ,Transplantation ,business.industry ,Hazard ratio ,Hematology ,Middle Aged ,Allografts ,HLA Mismatch ,Surgery ,Regimen ,Hematologic Neoplasms ,Histocompatibility ,030220 oncology & carcinogenesis ,Cohort ,Female ,business ,Whole-Body Irradiation ,030215 immunology - Abstract
The impact of HLA mismatch in hematopoietic stem cell transplantation with reduced-intensity conditioning (RIC) has not been fully examined. We analyzed a total of 1130 cases to examine the effects of HLA allele mismatch in unrelated bone marrow transplantation (BMT) with RIC in the Japan Marrow Donor Program registry cohort. Compared with HLA 8/8–allele match (n = 720, 8/8 match), both 1 (n = 295, 7/8 match) and 2 allele mismatches (n = 115, 6/8 match) were associated with significant reduction of overall survival (OS) (hazard ratio [HR], 1.34; P = .0024 and HR, 1.33; P = .035 for 7/8 and 6/8 match, respectively). The incidence of grades 2 to 4 acute graft-versus-host disease (aGVHD) increased with increasing number of mismatched alleles (HR, 1.36 and HR, 2.08 for 7/8 and 6/8 match, respectively). Nonrelapse mortality showed a similar tendency to aGVHD (HR, 1.35 for 7/8 and HR, 1.63 for 6/8). One-allele mismatches at the HLA-A or -B and HLA-C loci were significantly associated with inferior OS compared with 8/8 match (HR, 1.64 for A or B mismatch and HR, 1.41 for C mismatch), whereas HLA-DRB1 allele mismatch was not (HR, 1.16; P = .30). However, the effect of HLA-A or -B and -C mismatch on OS was not observed in those who received RIC BMT since 2010, in contrast to recipients before 2010. These results suggested that in unrelated RIC BMT, 1-allele mismatch is associated with poorer outcome, and the impact of HLA mismatch may differ depending on the HLA locus, although these HLA mismatch effects may be different in recent cases.
- Published
- 2017
115. About the optical properties of oxidized black silicon structures
- Author
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Kentaro Imamura, Michal Kučera, Emil Pinčík, Pavel Vojtek, Róbert Brunner, Milan Mikula, Peter Švec, Hikaru Kobayashi, Miroslav Zahoran, Ján Greguš, and Zuzana Zábudlá
- Subjects
Photoluminescence ,Materials science ,Nanostructure ,business.industry ,Band gap ,020209 energy ,Black silicon ,Analytical chemistry ,General Physics and Astronomy ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Blueshift ,chemistry.chemical_compound ,Optics ,chemistry ,X-ray crystallography ,0202 electrical engineering, electronic engineering, information engineering ,Crystallite ,0210 nano-technology ,business ,Luminescence - Abstract
The paper deals with the optical and morphological properties of thermally oxidized black silicon (OBSi) nano-crystalline specimens produced by the surface structure chemical transfer method (SSCT). This method can produce a nano-crystalline Si black color layer on c-Si with a range of thickness of ∼50 nm to ∼300 nm by the contact of c-Si immersed in chemical solutions HF + H2O2 with a catalytic mesh. We present and discuss mainly the photoluminescence properties of both polished c-Si and OBSi structures, respectively. The similar photoluminescence (PL) behaviors recorded at liquid helium (6 K) and room temperatures on both polished crystalline Si and OBSi samples, respectively, indicate the similar origin of recorded luminescence light. As the positions of PL maxima of OBSi structures are mainly related to the size of Si nanocrystallites and SiO(x), we therefore suppose that the size of the dominant parts of the luminated OBSi nanostructure is pre-determined by the used polishing Si procedure, and/or the distribution function of the number of formed crystallites on their size is very similar. The blue shift of both PL spectra reaching almost value of 0.40 eV observed after the decrease of the sample temperature to 6 K we relate also with the change of the semiconductor band gap width.
- Published
- 2017
116. Light trapping of crystalline Si solar cells by use of nanocrystalline Si layer plus pyramidal texture
- Author
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Takaaki Nonaka, Daichi Irishika, Yuya Onitsuka, Kentaro Imamura, and Hikaru Kobayashi
- Subjects
010302 applied physics ,Photocurrent ,Materials science ,Passivation ,business.industry ,General Physics and Astronomy ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Carrier lifetime ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Nanocrystalline material ,Surfaces, Coatings and Films ,Optics ,0103 physical sciences ,Optoelectronics ,Wafer ,Texture (crystalline) ,0210 nano-technology ,business ,Layer (electronics) ,Phosphosilicate glass - Abstract
The surface structure chemical transfer (SSCT) method has been applied to fabrication of single crystalline Si solar cells with 170 μm thickness. The SSCT method, which simply involves immersion of Si wafers in H2O2 plus HF solutions and contact of Pt catalyst with Si taking only ∼30 s for 6 in. wafers, can decrease the reflectivity to less than 3% by the formation of a nanocrystalline Si layer. However, the reflectivity of the nanocrystalline Si layer/flat Si surface/rear Ag electrode structure in the wavelength region longer than 1000 nm is high because of insufficient absorption of incident light. The reflectivity in the long wavelength region is greatly decreased by the formation of the nanocrystalline Si layer on pyramidal textured Si surfaces due to an increase in the optical path length. Deposition of phosphosilicate glass (PSG) on the nanocrystalline Si layer for formation of pn-junction does not change the ultralow reflectivity because the surface region of the nanocrystalline Si layer possesses a refractive index of 1.4 which is nearly the same as that of PSG of 1.4–1.5. The PSG layer is found to passivate the nanocrystalline Si layer, which is evident from an increase in the minority carrier lifetime from 12 to 44 μs. Hydrogen treatment at 450 °C further increases the minority carrier lifetime approximately to a doubled value. The solar cells with the structure show a high conversion efficiency of 18.5% in spite of the simple cell structure without antireflection coating. In this case, the short circuit photocurrent density is 40.1 mA/cm2 under AM1.5 100 mW/cm2 irradiation.
- Published
- 2017
117. Improvement of Cyclability of Li-Ion Batteries Using C-Coated Si Nanopowder Electrode Fabricated from Si Swarf with Limitation of Delithiation Capacity
- Author
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Hirotomo Nishihara, Taketoshi Matsumoto, Hikaru Kobayashi, Katsuya Kimura, Takatoshi Kasukabe, and Takashi Kyotani
- Subjects
Battery (electricity) ,Materials science ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Metallurgy ,High capacity ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,Chemical engineering ,Electrode ,0202 electrical engineering, electronic engineering, information engineering ,Materials Chemistry ,Electrochemistry ,Voltage range ,0210 nano-technology ,Ball mill ,Swarf - Abstract
We have fabricated Si nanopowder from Si swarf using the simple ball milling method, and applied to Li-ion battery electrodes. Limitation of the delithiation capacity after deep lithiation at 0.01 V is the most effective to achieve a constant high capacity for long cycles. The delithiation capacity keeps constant at 1500 mAh/g until the 290th cycle, and it slightly decreases to 1480 mAh/g at the 300th cycle. However, without limitation of the lithiation and delithiation capacities in the voltage range between 1.5 and 0.01 V, the delithiation capacity monotonically decreases with the cycle number, and it becomes 950 mAh/g at the 300th cycle. With limitation of the lithiation capacity at 1500 mAh/g after deep delithiation at 1.5 V, the delithiation capacity keeps 1470 mAh/g until the 137th cycle, and then decreases monotonically with the cycles to 860 mAh/g at the 300th cycle. With limitation of the delithiation capacity, the overvoltage estimated from the lithiation and delithiation curves is the lowest, and peeling-off of Si nanopowder from the Si electrode is suppressed because of limited size changes of Si nanopowder during lithiation and delithiation of Si nanopowder.
- Published
- 2017
118. Photoluminescence from vibrational excited-states for organic molecules adsorbed on Si nanoparticles
- Author
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Masanori Maeda, Hikaru Kobayashi, and Taketoshi Matsumoto
- Subjects
Materials science ,Photoluminescence ,Relaxation (NMR) ,Solvation ,Analytical chemistry ,General Physics and Astronomy ,Nanoparticle ,02 engineering and technology ,Electron ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Excited state ,Vibronic spectroscopy ,Physical and Theoretical Chemistry ,Atomic physics ,0210 nano-technology ,Excitation - Abstract
Herein, Si nanoparticles have been fabricated from Si swarf using a bead milling method. The adsorption of 9,10-dimethylanthracene (DMA) on Si nanoparticles enhances the photoluminescence (PL) intensity by ∼60 000 times that of DMA in hexane. The PL spectra possess peaked structures due to the vibronic transition of DMA. For the excitation energies higher than 4.0 eV, vibronic bands with energies higher than the (0, 0) band were observed and attributed to PL from the vibrational excited-states. The excitation spectra showed that incident light was absorbed by both DMA and the Si nanoparticles. The lifetime of the photo-generated electron-hole pairs in the Si nanoparticles was much longer than the DMA PL lifetime; this indicated that either a hole or an electron transferred to DMA first, followed by an opposite charge transfer. In the cases where a hole is first transferred to DMA, an electronic ground-state is stabilized via solvation. When an electron is captured by the potential of the electronic excited-state, transitions from the vibrational excited-states proceed due to the high transition probability, generating PL bands with energies higher than the (0, 0) band. In the cases where an electron is first transferred to DMA, internal relaxation to the vibrational ground-state occurs, and the potential of the electronic excited-state is lowered via solvation.
- Published
- 2017
119. Fabrication Mechanism of Atomically Flat n-Type 4H-SiC (000-1) Surfaces by Electrochemical Method
- Author
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Kentaro Imamura, Hikaru Kobayashi, and Tomoki Akai
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010302 applied physics ,Fabrication ,Materials science ,0103 physical sciences ,Nanotechnology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,0210 nano-technology ,Electrochemistry ,01 natural sciences ,Mechanism (sociology) ,Electronic, Optical and Magnetic Materials - Published
- 2017
120. Mechanism of Low Temperature Oxidation of 4H-SiC by Nitric Acid Vapor Oxidation Method at 600°C
- Author
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Hye-Suk Joe, Taketoshi Matsumoto, and Hikaru Kobayashi
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010302 applied physics ,chemistry.chemical_compound ,Materials science ,chemistry ,Nitric acid ,0103 physical sciences ,Inorganic chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,Mechanism (sociology) ,Electronic, Optical and Magnetic Materials - Published
- 2017
121. Effect of HCN passivation on silicon oxide thin layer
- Author
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Emil Pinčík, Masao Takahashi, Milan Mikula, Hikaru Kobayashi, and Martin Kopáni
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010302 applied physics ,Materials science ,Silicon ,Passivation ,Silicon dioxide ,technology, industry, and agriculture ,Oxide ,Analytical chemistry ,chemistry.chemical_element ,Infrared spectroscopy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,chemistry.chemical_compound ,chemistry ,0103 physical sciences ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Silicon oxide ,Layer (electronics) - Abstract
Silicon dioxide layers are materials with unique dielectric and interface properties. We investigated samples with SiO2 layers prepared with nitric acid oxidation of silicon (NAOS) method and with natural oxide layer after passivation with HCN aqueous solution. Samples were investigated with atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. We found higher roughness of layers after passivation and different effects of HCN passivation on samples. From the measurements, we conclude that HCN passivation influences structural and optical properties of SiO2 layer.
- Published
- 2016
122. Improvement of the positive bias stability of a-IGZO TFTs by the HCN treatment
- Author
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Hikaru Kobayashi, Myung-Jea Choi, Myeong-Ho Kim, Katsuya Kimura, and Duck-Kyun Choi
- Subjects
Passivation ,Cyanide ,Analytical chemistry ,02 engineering and technology ,01 natural sciences ,Stability (probability) ,law.invention ,Ion ,Stress (mechanics) ,chemistry.chemical_compound ,law ,0103 physical sciences ,Materials Chemistry ,Electrical and Electronic Engineering ,Saturation (magnetic) ,010302 applied physics ,business.industry ,Transistor ,Electrical engineering ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Threshold voltage ,chemistry ,0210 nano-technology ,business - Abstract
In recent years, many researchers have attempted to improve the bias stability of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs). In this study, the hydrogen cyanide (HCN) treatment was carried out to improve the positive bias stability of bottom-gate a-IGZO TFTs. The HCN treatment was performed using a 0.1 M HCN solution with a pH of 10 at room temperature. Before applying the positive bias stress, there were no differences in the major electrical properties, including the saturation mobility ( μ sat ), threshold voltage (V th ), and subthreshold swing (S/S), between HCN-treated and non-HCN-treated devices. However, after applying the positive bias stress, the HCN-treated device showed superior bias stability compared to the non-HCN-treated device. This difference is associated with the passivation of the defect states and the surface of the back-channel layer of the HCN-treated device by cyanide ions.
- Published
- 2016
123. Efficacy of hypothermia therapy in patients with acute encephalopathy with biphasic seizures and late reduced diffusion
- Author
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Madoka Hoshide, Ayumi Sakakibara, Takeshi Matsushige, Ippei Hidaka, Shunji Hasegawa, Hiroki Yasudo, Reiji Hirano, Hikaru Kobayashi, Takashi Ichiyama, Hirofumi Inoue, Yoshiko Nawata, and Fumitaka Kohno
- Subjects
Male ,Acute encephalopathy ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,Developmental Neuroscience ,Hypothermia, Induced ,Seizures ,Outcome Assessment, Health Care ,Medicine ,Humans ,In patient ,Child ,Wechsler Intelligence Scale for Children ,Retrospective Studies ,Brain Diseases ,Intelligence quotient ,business.industry ,Wechsler Adult Intelligence Scale ,Infant ,General Medicine ,Hypothermia ,University hospital ,medicine.disease ,Prognosis ,Anesthesia ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Acute Disease ,Female ,Neurology (clinical) ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Background Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized by biphasic seizures and impaired consciousness. The efficacy of hypothermia/normothermia therapy in patients with AESD has rarely been reported on. Methods We enrolled 15 patients with AESD admitted to Yamaguchi University Hospital and Yamaguchi-ken Saiseikai Shimonoseki General Hospital between 2005 and 2019 and retrospectively evaluated the long-term efficacy of hypothermia therapy compared to that of non-hypothermia therapy. We compared the long-term sequelae of patients with AESD treated with or without hypothermia therapy. We used the Pediatric Cerebral Performance Category (PCPC) scale and intelligence tests including the Wechsler Intelligence Scale for Children, Tanaka-Binet Intelligence Scale, and Enjoji Infantile Developmental Scale to evaluate neurological sequelae and mental disability. The preventive effect of hypothermia therapy was assessed based on the development of post-encephalopathic epilepsy (PEE). Results There was no significant between-group difference in the PCPC score (p = 0.53). The subjects with severe mental disability in the hypothermia therapy group were 0 (0%), while those in the non-hypothermia group were 2 (29%); however, the difference was not significant. Notably, there were no patients with onset of PEE in the hypothermia therapy group, while there were 4 (57.1%) in the non-hypothermia group (p = 0.03). Conclusions Our study suggests that hypothermia therapy may be effective in the long-term sequelae of AESD in terms of preventing the development of PEE. We propose that hypothermia therapy could contribute to improve the quality of life in these patients by preventing the subsequent onset of PEE.
- Published
- 2019
124. Improvement of early mortality in single-unit cord blood transplantation for Japanese adults from 1998 to 2017
- Author
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Tetsuya Eto, Hiromi Hayashi, Yoshihiro Inamoto, Fumihiko Kimura, Yoshinobu Kanda, Satoshi Takahashi, Yasuhiro Sugio, Hikaru Kobayashi, Yoshiko Atsuta, Junichi Mukae, Takahiro Fukuda, Yasushi Kouzai, Naoyuki Uchida, Minoko Takanashi, Shinichi Kobayashi, Masatsugu Tanaka, Yoshiko Matsuhashi, Junya Kanda, and Takaaki Konuma
- Subjects
Change over time ,Adult ,Graft Rejection ,Male ,medicine.medical_specialty ,Multivariate analysis ,Adolescent ,Neutrophils ,Multiple Organ Failure ,Graft vs Host Disease ,Disease ,Infections ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Japan ,Internal medicine ,medicine ,Humans ,Young adult ,Cord blood transplantation ,Survival analysis ,Aged ,Neutrophil Engraftment ,business.industry ,Incidence (epidemiology) ,Incidence ,Graft Survival ,Hematology ,Middle Aged ,Survival Analysis ,Treatment Outcome ,030220 oncology & carcinogenesis ,Female ,Cord Blood Stem Cell Transplantation ,business ,030215 immunology ,Follow-Up Studies - Abstract
The major limitation of cord blood transplantation (CBT) for adults remains the delayed hematopoietic recovery and higher incidence of graft failure, which result in a higher risk of early mortality in CBT. We evaluated early overall survival (OS), non-relapse mortality (NRM), neutrophil engraftment, acute graft-vs-host disease, and cause of early death among 9678 adult patients who received single-unit CBT in Japan between 1998 and 2017. The probability of OS at 100 days was 64.4%, 71.7%, and 78.9% for the periods 1998 to 2007, 2008 to 2012, and 2013 to 2017, respectively (P < .001). The cumulative incidences of NRM at 100 days during the same period were 28.3%, 20.8%, and 14.6%, respectively (P < .001). The cumulative incidences of neutrophil engraftment were also improved during the same period (P < .001). The most common cause of death within 100 days after CBT was bacterial infection in 1998 to 2007 and primary disease in the latter two time periods. Across the three time periods, the proportions of deaths from bacterial and fungal infection, graft failure, hemorrhage, sinusoidal obstructive syndrome, and organ failure decreased in a stepwise fashion. Landmark analysis of OS and NRM after 100 days showed that OS did not change over time in the multivariate analysis. Our registry-based data demonstrated a significant improvement of early OS after CBT for adults over the past 20 years. The landmark analysis suggested that improvement of early mortality could lead to an improvement of long-term OS after CBT.
- Published
- 2019
125. Magnesium-dependent activated partial thromboplastin time assay-Simple method for lupus anticoagulant detection
- Author
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Masahiro Ieko, Fumihiro Ishida, Takayoshi Tokutake, Sumiyoshi Naito, Hisami Baba, Mika Yoshida, and Hikaru Kobayashi
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Clinical Biochemistry ,chemistry.chemical_element ,030204 cardiovascular system & hematology ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Antiphospholipid syndrome ,Internal medicine ,medicine ,Humans ,Magnesium ,Child ,Coagulation Disorder ,Aged ,Aged, 80 and over ,Lupus anticoagulant ,medicine.diagnostic_test ,biology ,Chemistry ,Biochemistry (medical) ,Infant ,Hematology ,General Medicine ,Middle Aged ,medicine.disease ,Antiphospholipid Syndrome ,Clotting time ,Child, Preschool ,Lupus Coagulation Inhibitor ,Acquired hemophilia ,biology.protein ,Female ,Partial Thromboplastin Time ,Antibody ,circulatory and respiratory physiology ,030215 immunology ,Partial thromboplastin time - Abstract
INTRODUCTION Detection of lupus anticoagulant (LA), an antiphospholipid (aPL) antibody, in a clotting time test is an important finding for diagnosis of antiphospholipid syndrome (APS). However, confirmation of LA requires several different testing procedures, some of which can be difficult and require time. We report here a simple and highly specific method for detecting LA. MATERIALS AND METHODS We examined 66 plasma samples obtained from LA-positive (LA) and 75 from LA-negative (non-LA) subjects, which included patients with acquired hemophilia and coagulation disorders, as well as from 43 healthy volunteer samples as normal controls. Activated partial thromboplastin time (APTT) was determined by adding 20 mmol of CaCl2 (Ca-APTT) or 25 mmol of a mixture of Mg and Ca (Mg-APTT). The ratio of Mg-APTT/Ca-APTT was then calculated and used as the Mg/Ca Index. RESULTS The Mg/Ca Index value for the LA group was significantly lower than that for the non-LA and normal control groups (P
- Published
- 2019
126. [Miliary tuberculosis with markedly elevated soluble interleukin-2 receptor levels mimicking intravascular large B-cell lymphoma]
- Author
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Hiroko, Kaiume, Masahiko, Sumi, Keijiro, Sato, Takehiko, Kirihara, Wataru, Takeda, Toshimitsu, Ueki, Yuki, Hiroshima, Masahide, Watanabe, and Hikaru, Kobayashi
- Subjects
Aged, 80 and over ,Diagnosis, Differential ,Respiratory Distress Syndrome ,Fatal Outcome ,Diabetes Mellitus, Type 2 ,Tuberculosis, Miliary ,Humans ,Female ,Receptors, Interleukin-2 ,Lymphoma, Large B-Cell, Diffuse - Abstract
An 81-year-old woman with type 2 diabetes mellitus presented to our hospital due to anorexia, leg edema, and respiratory distress. Laboratory results revealed anemia, thrombocytopenia, elevated lactate dehydrogenase, and markedly elevated soluble interleukin-2 receptor levels. Computed tomography showed ground-glass opacities and consolidation in both lung fields, but no lymphadenopathy was noted. Intravascular large B-cell lymphoma (IVLBCL) was considered as a differential diagnosis; therefore, bone marrow and random skin biopsy were performed. Her respiratory condition deteriorated, with the occurrence of acute respiratory distress syndrome, disseminated intravascular coagulation, hemophagocytic syndrome, and further alveolar hemorrhage. Methylprednisolone pulse therapy was performed, but did not improve the patient's condition. On hospital day 6, the acid-fast bacterial smear of the sputum using the Gaffky scale was 2, and on the next day, tuberculosis DNA was detected in the polymerase chain reaction. In the bone marrow biopsy, multiple epithelioid cell granulomas were found; thus, the patient was diagnosed with miliary tuberculosis. Although anti-tuberculosis therapy was started immediately, she died on hospital day 22. The soluble interleukin-2 receptor level increased up to 19,400 U/ml. The differential diagnosis should be cautiously made because miliary tuberculosis can mimic IVLBCL.
- Published
- 2019
127. Analysis of Coexistence Phenomena in Piecewise-Constant Oscillators Coupled by Hysteresis Elements
- Author
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Tadashi Tsubone and Hikaru Kobayashi
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Physics ,Van der Pol oscillator ,Wave propagation ,020206 networking & telecommunications ,02 engineering and technology ,Inductor ,Synchronization ,Hysteresis ,Classical mechanics ,0202 electrical engineering, electronic engineering, information engineering ,Piecewise ,020201 artificial intelligence & image processing ,Focus (optics) ,Constant (mathematics) - Abstract
This study investigates piecewise-constant oscillators coupled by hysteresis elements. Coexistence phenomena of inphase and anti-phase synchronizations are observed in van der Pol oscillators coupled by inductors. Wave propagation phenomena called phase-inversion waves are observed in oscillators coupled as a ladder, a ring and so on. We focus on piecewise-constant oscillators which can be strictly and easily analyzed. In this report, we confirm by using analysis with rigorous solutions, in-and-anti-phase synchronization, in-phase synchronization and phase-inversion waves are coexisting in combination of initial values, and coexistence phenomena disappears by changing parameter corresponding to threshold value of hysteresis elements of coupled terms.
- Published
- 2019
128. Lymphoproliferation Impairment and Oxidative Stress in Blood Cells from Early Parkinson’s Disease Patients
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Mónica De la Fuente, Irene Martínez de Toda, José Antonio Molina, Antonio Garrido, Carmen Vida, Hikaru Kobayashi, and Eva Carro
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Male ,0301 basic medicine ,Parkinson's disease ,lymphoproliferation ,Neutrophils ,immune functions ,oxidative damage ,medicine.disease_cause ,lcsh:Chemistry ,chemistry.chemical_compound ,0302 clinical medicine ,Malondialdehyde ,oxidative stress ,Lymphocytes ,lcsh:QH301-705.5 ,Spectroscopy ,Whole blood ,immunosenescence ,Parkinson Disease ,General Medicine ,Immunosenescence ,Glutathione ,Computer Science Applications ,Female ,Oxidation-Reduction ,Adult ,medicine.medical_specialty ,Neurociencias ,Peripheral blood mononuclear cell ,Article ,Catalysis ,Parkinson’s Disease ,Inorganic Chemistry ,03 medical and health sciences ,Immune system ,Internal medicine ,medicine ,Humans ,Physical and Theoretical Chemistry ,Molecular Biology ,Aged ,Cell Proliferation ,Glutathione Peroxidase ,Blood Cells ,Biología celular ,business.industry ,Organic Chemistry ,biomarkers ,medicine.disease ,nervous system diseases ,Cross-Sectional Studies ,030104 developmental biology ,Endocrinology ,lcsh:Biology (General) ,lcsh:QD1-999 ,chemistry ,business ,030217 neurology & neurosurgery ,Lymphoproliferative response ,Oxidative stress - Abstract
In Parkinson&rsquo, s Disease (PD), the peripheral changes in the functional capacity and redox state of immune cells has been scarcely investigated, especially in the early PD stages. Aging is a risk factor for PD, and the age-related impairment of the immune system, based on a chronic-oxidative stress situation, is involved in the rate of aging. We analyzed several functions in isolated peripheral blood neutrophils and mononuclear cells from PD stage 2 patients, and compared the results to those in healthy elderly and adult controls. Several oxidative stress and damage parameters were studied in whole blood cells. The results showed an impairment of the lymphoproliferative response in stimulated conditions in the PD patients compared with age-matched controls, who also showed typical immunosenescence in comparison with adult individuals. Higher oxidative stress and damage were observed in whole blood cells from PD patients (lower glutathione peroxidase activity, and higher oxidized glutathione and malondialdehyde contents). Our results suggest an accelerated immunosenescence in PD stage 2, and that several of the parameters studied could be appropriate peripheral biomarkers in the early stages of PD.
- Published
- 2019
129. The Increase of the Reactivity of Molecular Hydrogen with Hydroxyl Radical from the Gas Phase versus an Aqueous Environment: Quantum Chemistry and Transition State-Theory Calculations
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Hikaru Kobayashi, Andrea Lombardi, Vincenzo Aquilanti, Nayara D. Coutinho, Valter H. Carvalho-Silva, Yuki Kobayashi, Toshio Kasai, Federico Palazzetti, and Eduardo C. Vaz
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Aqueous solution ,Hydrogen ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Chemical kinetics ,chemistry.chemical_compound ,chemistry ,Computational chemistry ,Elementary reaction ,Water environment ,Hydroxyl radical ,Reactivity (chemistry) ,Solvent effects ,0210 nano-technology - Abstract
One of the simplest elementary reactions, that between H2 and OH, is of great theoretical interest in chemical kinetics. Surprisingly it turned out recently to be of importance in medical and biological environments, in search of role of hydrogen as radical scavenger participating in the human body: water is supposed to be of possible influence in this reaction. However, there are no theoretical studies considering solvent effects in the title reaction which in the gas phase is slow. Here, we aim to analyze the H2 + OH reaction with a blend of electronic structure calculations and the deformed Transition-State Theory (\( d \)-TST) approach. Inclusion of the continuum solvation model density (SMD) was applied for mimicking the role of the aqueous phase. Preliminary results demonstrate an enormous increase in the reactivity between H2 and OH molecules in water environment, approximately 150- and 138-fold at 25 ℃ and 36.5 ℃, respectively. We expect that these results can help to shed new light on the understanding of the H2 + OH reaction in aqueous phase, paving the way to research for medical and technological applications.
- Published
- 2019
130. Intra-grain conduction of self-doped polyaniline.
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Yuki Usami, Kentaro Imamura, Tomoki Akai, Dock-Chil Che, Hiroshi Ohoyama, Hikaru Kobayashi, and Takuya Matsumoto
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CONDUCTION electrons ,POLYANILINES ,SURFACE coatings ,ELECTRODES ,MOLECULAR electronics ,NANOELECTROMECHANICAL systems - Abstract
The conduction behavior of ultrathin films (about 10 nm thick) composed of self-doped water-soluble polyaniline sulfonate (SPAN) was investigated using nano-gap electrodes under vacuum conditions. The conductance was found to be ohmic even in the high field regime up to 10
5 V cm-1 over a temperature range of 10-300K. The temperature dependence of the conductance indicated that SPAN gave the extremely high value of localization length (L) = 300 nm without secondary doping, in comparison with conventional polyaniline. We propose that SPAN forms long-range highly crystalline metallic grains, and we observed intra-grain conduction due to some grains directly bridging the two nano-gap electrodes at low temperature. We conclude that inter-grain conduction becomes dominant as the temperature increases. [ABSTRACT FROM AUTHOR]- Published
- 2016
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131. About complex refractive index of black Si
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Milan Mikula, Hikaru Kobayashi, Emil Pinčík, and Róbert Brunner
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chemistry.chemical_compound ,Materials science ,chemistry ,business.industry ,020209 energy ,Black silicon ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,02 engineering and technology ,Porous silicon ,business ,Refractive index - Abstract
The paper deals with the complex refractive index in the IR light region of two types of samples (i) as prepared black silicon, and (ii) thermally oxidized black silicon (BSi) nano-crystalline specimens produced both by the surface structure chemical transfer method using catalytic Ag evaporated spots (as prepared sample) and by the catalytic Pt catalytic mesh (thermally oxidized sample). We present, compare, and discuss the values of the IR complex refractive index obtained by calculation using the Kramers-Krönig transformation. Results indicate that small differences between optical properties of as prepared black Si and thermally oxidized BSi are given by: (i) – oxidation procedure, (ii) – thickness of the formed black Si layer, mainly, not by utilization of different catalytic metals, and by iii) the different thickness. Contamination of the surface by different catalytic metals contributes almost equally to the calculated values of the corresponding complex refractive index.
- Published
- 2017
132. Microstructure and optical properties of black silicon layers
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Martin Králik, Kentaro Imamura, Emil Pinčík, Stanislav Jurečka, Taketoshi Matsumoto, and Hikaru Kobayashi
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chemistry.chemical_compound ,Void (astronomy) ,Materials science ,chemistry ,Silicon ,Black silicon ,chemistry.chemical_element ,Surface structure ,Composite material ,Microstructure ,Reflectivity ,Refractive index ,Nanocrystalline material - Abstract
Black silicon structures were formed by etching of silicon substrates based on the surface structure chemical transfer method. Formed structures show gradient of material density in the nanocrystalline Si layer leading to ultralow spectral reflectance below 3% in wide spectral region. In study of the development of microstructure properties during the forming procedure the TEM images were used. Information abut the microstructure observed in the TEM images was analysed by the Abbott-Firestone method. By using this approach limiting conditions for the black silicon layer formation were obtained. Spectral reflectances of studied samples were modelled by using the effective medium theory. Multilayer theoretical model based on splitting the black silicon layer into 20 sublayers was constructed. Optical properties of each individual sublayer were described by using Bruggeman effective media theory combining Si, SiO2 and void fractions. Gradual development of real and imaginary part of complex index of refraction was observed in the volume of black silicon layers. Results of optical analysis correspond to the microstructure development during sample forming.
- Published
- 2018
133. Comparison of Outcomes of Allogeneic Transplantation for Primary Myelofibrosis among Hematopoietic Stem Cell Source Groups
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Sung-Won Kim, Takeshi Kondo, Hiroatsu Ago, Yoshiko Atsuta, Kazuteru Ohashi, Yukiyasu Ozawa, Yoshinobu Kanda, Jun Ishikawa, Takahiro Fukuda, Makoto Hirokawa, Hikaru Kobayashi, Kazuhiro Ikegame, Katsuto Takenaka, Makoto Murata, and Naoyuki Uchida
- Subjects
Adult ,Male ,medicine.medical_specialty ,Allogeneic transplantation ,medicine.medical_treatment ,Hematopoietic stem cell transplantation ,Umbilical cord ,Disease-Free Survival ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Registries ,Myelofibrosis ,Aged ,Retrospective Studies ,Transplantation ,Peripheral Blood Stem Cell Transplantation ,business.industry ,Hematopoietic stem cell ,Retrospective cohort study ,Hematology ,Middle Aged ,medicine.disease ,Allografts ,Hematopoietic Stem Cells ,Survival Rate ,surgical procedures, operative ,medicine.anatomical_structure ,Primary Myelofibrosis ,030220 oncology & carcinogenesis ,Female ,Bone marrow ,Cord Blood Stem Cell Transplantation ,business ,Erythrocyte Transfusion ,Unrelated Donors ,030215 immunology - Abstract
The choice of alternative donor is a major issue in allogeneic hematopoietic stem cell transplantation (HSCT) for patients with primary myelofibrosis (PMF) without an HLA-matched related donor. We conducted this retrospective study using the Japanese national registry data for 224 PMF patients to compare the outcomes of first allogeneic HSCT from HLA-matched related donor bone marrow (Rtd-BM), HLA-matched related donor peripheral blood stem cells (Rtd-PB), HLA-matched unrelated donor bone marrow (UR-BM), unrelated umbilical cord blood (UR-UCB), and other hematopoietic stem cell grafts. Nonrelapse mortality (NRM) rates at 1 year after Rtd-BM, Rtd-PB, UR-BM, UR-UCB, and other transplantations were 16%, 36%, 30%, 41%, and 48%, respectively. Multivariate analysis identified UR-UCB transplantation, other transplantation, frequent RBC transfusion before transplantation, and frequent platelet (PLT) transfusion before transplantation as predictive of higher NRM. Relapse rates at 1 year after Rtd-BM, Rtd-PB, UR-BM, UR-UCB, and other transplantation were 14%, 17%, 11%, 14%, and 15%, respectively. No specific factor was associated with the incidence of relapse. Overall survival (OS) at 1 and 4 years after Rtd-BM, Rtd-PB, UR-BM, UR-UCB, and other transplantation were 81% and 71%, 58% and 52%, 61% and 46%, 48% and 27%, and 48% and 41%, respectively. Multivariate analysis identified older patient age, frequent RBC transfusion before transplantation, and frequent PLT transfusion before transplantation as predictive of lower OS. In conclusion, UR-UCB transplantation, as well as UR-BM transplantation, can be selected for PMF patients without an HLA-identical related donor. However, careful management is required for patients after UR-UCB transplantation because of the high NRM. Further studies including more patients after HLA-haploidentical related donor and HLA-mismatched unrelated donor transplantation would provide more valuable information for patients with PMF when making decisions regarding the choice of alternative donor.
- Published
- 2018
134. Impact of Graft-Versus-Host Disease on Lymphoma Progression after Allogeneic Stem Cell Transplantation: Retrospective Analysis from the Adult Lymphoma Working Group of the Japan Society for Hematopoietic Cell Transplantation (JSHCT)
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Eisei Kondo, Junya Kanda, Mizuki Watanabe, Yoshiko Atsuta, Kazuhiro Ikegame, Naoyuki Uchida, Takahiro Fukuda, Hikaru Kobayashi, Jun Kato, and Ritsuro Suzuki
- Subjects
Oncology ,Transplantation ,medicine.medical_specialty ,Hematopoietic cell ,business.industry ,Adult Lymphoma ,Cell Biology ,Hematology ,medicine.disease ,Lymphoma ,Graft-versus-host disease ,Internal medicine ,medicine ,Retrospective analysis ,Molecular Medicine ,Immunology and Allergy ,Stem cell ,business - Published
- 2021
135. Unveiling the Role of Al 2 O 3 Interlayer in Indium–Gallium–Zinc–Oxide Transistors
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Tae Hyeon Kim, Hye Yeon Jang, Seyoung Oh, Jae Hyeon Nam, Woojin Park, Naohito Yamada, Hikaru Kobayashi, Byoung Hun Lee, Hiroki Habazaki, Soyoung Kim, and Byung Jin Cho
- Subjects
Indium gallium zinc oxide ,Materials science ,law ,Transistor ,Inorganic chemistry ,Materials Chemistry ,Surfaces and Interfaces ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Volta potential ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention - Published
- 2021
136. Changes in structure and surface properties of Si-based agent during hydrogen generation reaction
- Author
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Yoshihito Kowada, Hikaru Kobayashi, Yuki Kobayashi, and Tatsuro Shirohata
- Subjects
Suboxide ,Materials science ,Hydrogen ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Nanocrystal ,Chemical engineering ,chemistry ,Agglomerate ,Desorption ,Crystallite ,0210 nano-technology ,Silicon oxide ,Hydrogen production - Abstract
Si-based agent which can generate a high amount of hydrogen by the reaction with weak alkaline solutions (e.g., pH8.3) has been investigated using SEM, XRD, DLS, XPS and FT-IR. Si-based agent consists of crystalline Si with the average crystallite size of ~20 nm, and Si nanocrystals form agglomerate with ~150 nm average size. The size of agglomerate slightly decreases from ~150 nm to ~130 nm during the initial hydrogen generation reaction stage up to 500 min in pH8.3 solutions at 36 °C and then the agglomerate size stays constant. The observed curve of the generated hydrogen volume vs. the reaction time is reasonably well expressed by the observed size change of Si crystallites, and also by the thickness of the silicon oxide layer. Before the hydrogen generation reaction, hydrogen atoms are present at the Si/silicon oxide interface as SiH, SiH2, and SiH3, and also at the surface and in the silicon oxide layer, as HSiO, HSiO2, and HSiO3. The concentrations of all hydrogen-containing species increase in the initial reaction stage, and then, decrease with the hydrogen generation reaction time, indicating that generated hydrogen atoms attack Si H bonds, leading to desorption as H2.
- Published
- 2021
137. Mechanical properties of a polypropylene resin matrix composite material with a small amount of pulverized bamboo powder
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Arnaud Macadre, Hikaru Kobayashi, Koichi Goda, and Masato Shimizu
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Polypropylene ,Bamboo ,chemistry.chemical_compound ,Materials science ,Resin matrix ,chemistry ,Composite material - Published
- 2021
138. 日本風工学会デザイン賞を受賞して
- Author
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Hikaru KOBAYASHI and Hiroyuki TESHIMA
- Published
- 2021
139. Changes in the geometric structure and hydrogen-termination modify the electronic and optical properties of porous silicon
- Author
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Melanie David, Wilson Agerico Diño, Meena Rittiruam, Tosawat Seetawan, Hikaru Kobayashi, Allan Abraham B. Padama, and Yuya Hikita
- Subjects
Materials science ,Hydrogen ,Silicon ,Band gap ,Dangling bond ,food and beverages ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Porous silicon ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Physics::Geophysics ,Electronic, Optical and Magnetic Materials ,010309 optics ,chemistry ,Chemical physics ,0103 physical sciences ,Electrical and Electronic Engineering ,0210 nano-technology ,Porosity ,Refractive index - Abstract
Here, we show that the electronic and optical properties of silicon (Si) can be controlled by varying the amount of dangling bonds and the number of Si Si bonds in the system. By introducing pores in the bulk (in the form of Si vacancies), we can induce the appearance of gap states (states in the energy gap/forbidden region) in porous Si (pSi), as compared to pure Si. Terminating the Si atoms in the pores with hydrogen atoms (H) induces the disappearance of these induced gap states (IGS). As a result, we can continuously decrease (increase) the corresponding refractive indices of both pSi and H-terminated pSi by increasing (decreasing) the porosity.
- Published
- 2020
140. A Comparison of Outcomes for Cord Blood Transplantation and Unrelated Bone Marrow Transplantation in Adult Aplastic Anemia
- Author
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Yachiyo Kuwatsuka, Shinicihro Mori, Koji Iwato, Hirohito Yamazaki, Yoshiko Atsuta, Koichi Miyamura, Fumihiko Kimura, Toshihiro Miyamoto, Kazuteru Ohashi, Ken Ishiyama, Hikaru Kobayashi, Jun Kato, Yukiyasu Ozawa, Junya Kanda, Takehiko Mori, Shinichi Kako, Koji Kato, Yoshiyuki Takahashi, Naoyuki Uchida, Chiaki Kato, Tetsuya Eto, Kaoru Kahata, and Yoshinobu Kanda
- Subjects
Adult ,Graft Rejection ,medicine.medical_specialty ,Adolescent ,Cord Blood Stem Cell Transplantation ,Infections ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Japan ,Internal medicine ,Risk of mortality ,Humans ,Medicine ,Registries ,Young adult ,Aplastic anemia ,Aged ,Bone Marrow Transplantation ,Cause of death ,Transplantation ,Umbilical Cord Blood Transplantation ,business.industry ,Hazard ratio ,Age Factors ,Anemia, Aplastic ,Hematology ,Middle Aged ,medicine.disease ,Surgery ,Treatment Outcome ,030220 oncology & carcinogenesis ,Unrelated Donors ,business ,030215 immunology - Abstract
Earlier reports suggested that umbilical cord blood transplantation (UCBT) for aplastic anemia (AA) was feasible in alternative transplantation. To identify differences in outcomes of UCBT and HLA-matched or mismatched unrelated bone marrow transplantation (UBMT) in adults with AA, we analyzed registry data of the Japan Society for Hematopoietic Cell Transplantation and compared results of UCBT (n = 69) to 8/8-matched (n = 101), 7/8-matched (n = 65), or 6/8-matched (n = 37) UBMT. The transplantation period was from 2002 to 2012, and patients 16 years or older with AA were eligible. Median ages were 49, 35, 28, and 30 years for UCBT, 8/8-matched, 7/8-matched, and 6/8-matched UBMT, respectively. In multivariate analysis, risk of mortality was lower for 8/8-matched UBMT compared with that of UCBT (hazard ratio [HR], .55; 95% confidence interval [CI], .32 to .94; P = .029), adjusted for age and graft-versus-host disease (GVHD) prophylaxis, which were other associated factors. Mortality risks of 7/8-matched UBMT (HR, .55; 95% CI, .29 to 1.02) or 6/8-matched UBMT (HR, .67; 95% CI, .32 to 1.39) were not significantly different from those of UCBT. Risks of grade 3 or 4 acute and chronic GVHD were not different among the 4 groups. The most prevalent cause of death was graft failure in UCBT and 6/8-matched UBMT and infection in 8/8-matched and 7/8-matched UBMT. Under 40 years old,survival of UCBT was similar to that of UBMT (76%, 79%, 83%, and 83% for UCBT and 8/8-matched, 7/8-matched, and 6/8-matched UBMT, respectively, at 3 years), adjusted for transplantation period, which was another associated factor; however, for ages over 40 years, that of UCBT tended to be lower (47%, 64%, 64%, and 75% for UCBT, 8/8-matched, 7/8-matched, and 6/8-matched UBMT, respectively, at 3 years). To conclude, these data suggest that UCBT could be an alternative treatment option for younger adults when matched sibling or adequate UBMT donors are not available.
- Published
- 2016
141. Development of New Aqueous Resin Ink for Sign Graphics
- Author
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Masahiro Kido, Naohiro Toda, Tomohiro Nakagawa, Hidefumi Nagashima, Juichi Furukawa, Noriaki Okada, and Hikaru Kobayashi
- Published
- 2016
142. The photoluminescence of multicolor silicon
- Author
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Ján Greguš, Milan Mikula, Pavel Vojtek, Zuzana Zábudlá, Hikaru Kobayashi, Kentaro Imamura, Peter Švec, Emil Pinčík, and Róbert Brunner
- Subjects
Photoluminescence ,Materials science ,Silicon ,Black silicon ,Analytical chemistry ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Porous silicon ,01 natural sciences ,Nanocrystalline material ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Nanocrystal ,Quantum dot ,0210 nano-technology ,Luminescence - Abstract
The present paper deals with the photoluminescence (PL) of the multicolor silicon (MC-Si) – a nanocrystalline layer produced by the surface structure chemical transfer (SSCT) method on the p-type Si. The PL behaviours recorded at room temperature are compared with ∼500-nm-thick porous Si prepared electrochemically in the HF + methanol solution on the same Si substrate. The PL spectra of porous Si are shifted to higher energy in comparison with MC-Si. The PL records were fitted by Gaussian curves. We attribute the PL band of porous Si with maximum 2.3 eV to the own luminescence of ∼2.5-nm-thick nanocrystalline Si grains observed due to quantum confinement. This PL band is missing in the PL spectra of MC-Si structures due to the absence of Si nanocrystals of similar size. The PL bands of both MC-Si and porous Si between 1.89 and 2.05 eV are connected with SiO(x) compounds covering the surfaces of Si nanocrystals. Additional two PL bands of all MC-Si structures at 1.69–1.70 eV and 1.80–1.84 eV we rel...
- Published
- 2016
143. STUDY ON ZERO ENERGY LIGHTING SYSTEM FOR TOILET UNDER THE EMERGENCY SITUATION
- Author
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Mamiko Fujiyama, Hisashi Ishii, Toshikazu Ishida, and Hikaru Kobayashi
- Subjects
Toilet ,0208 environmental biotechnology ,Architecture ,Zero-point energy ,Environmental science ,Lighting system ,02 engineering and technology ,Building and Construction ,Simulation ,020801 environmental engineering - Published
- 2016
144. Total assessment for various environmentally conscious techniques from three perspectives: Mitigation of global warming, mitigation of UHIs, and adaptation to urban warming
- Author
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Kiyoshi Sasaki, Taiki Uchida, Akashi Mochida, Hikaru Kobayashi, and Saori Yumino
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Greening ,Climate change mitigation ,Renewable Energy, Sustainability and the Environment ,Urban warming ,Climatology ,Geography, Planning and Development ,Global warming ,Environmental science ,Transportation ,Urban heat island ,Adaptation (computer science) ,Environmental planning ,Civil and Structural Engineering - Abstract
This study proposed a new system to assess the effects of countermeasures used to mitigate global warming and urban heat islands (UHIs) and to simultaneously adapt to urban warming. This system was used to investigate the impact of highly reflective materials and greening on the vertical walls of buildings, based on coupled simulations of radiation, conduction, and convection. Under the conditions assumed in this study, greening and highly reflective materials had a positive impact on the mitigation of global warming and UHIs. However, in terms of adapting to urban warming, greening was not very effective and the highly reflective material had a clearly negative impact.
- Published
- 2015
145. ORAL ADMINISTRATION OF NANO-SIZED SILICON PARTICLES ATTENUATES OXIDATIVE STRESS AND ISCHEMIA-REPERFUSION INJURY IN A RAT MODEL: A NOVEL HYDROGEN ADMINISTRATION METHOD
- Author
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Toyofumi Abe, Norio Nonomura, Ayumu Taniguchi, Taigo Kato, Yuki Kobayashi, Masataka Kawamura, Hikaru Kobayashi, Shigeaki Nakazawa, Ryoichi Imamura, and Tomoko Namba-Hamano
- Subjects
Transplantation ,Hydrogen ,Silicon ,Rat model ,Ischemia ,chemistry.chemical_element ,Pharmacology ,medicine.disease ,medicine.disease_cause ,chemistry ,Oral administration ,medicine ,Nano sized ,Reperfusion injury ,Oxidative stress - Published
- 2020
146. Urgent need to review domestic regulations in Japan for preventing illegal transboundary movement of hazardous wastes
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Kana Miyamoto and Hikaru Kobayashi
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Economics and Econometrics ,Hazardous waste ,Business ,Waste Management and Disposal ,Environmental planning - Published
- 2020
147. Communication—Enhancement of Boron Back-Surface-Field and Suppression of Auger Recombination to Improve Ultralow-Reflectance Si Solar Cells
- Author
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Hikaru Kobayashi, Shogo Kunieda, and Kentaro Imamura
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symbols.namesake ,Back surface field ,Materials science ,Auger effect ,chemistry ,business.industry ,symbols ,Optoelectronics ,chemistry.chemical_element ,business ,Boron ,Reflectivity ,Electronic, Optical and Magnetic Materials - Published
- 2020
148. Second cord blood transplantation and interferon-α maintenance therapy for relapsed Ph+ acute lymphoblastic leukemia with the T315I mutation
- Author
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Takehiko Kirihara, Yuki Hiroshima, Masahiko Sumi, Wataru Takeda, Keijiro Sato, Hikaru Kobayashi, Toshimitsu Ueki, and Hiroko Kaiume
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Cancer Research ,business.industry ,Lymphoblastic Leukemia ,hemic and immune systems ,Hematology ,Minimal residual disease ,T315i mutation ,Ph+ acute lymphoblastic leukemia ,03 medical and health sciences ,Haematopoiesis ,0302 clinical medicine ,Oncology ,Maintenance therapy ,hemic and lymphatic diseases ,030220 oncology & carcinogenesis ,Interferon α ,Cancer research ,Medicine ,business ,Cord blood transplantation ,030215 immunology - Abstract
In 2008, we reported a case of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) with the continued detection of minimal residual disease after allogeneic hematopoietic stem c...
- Published
- 2016
149. Pulmonary mucormycosis developed during acute myelogenous leukemia and successfully treated by surgical resection before blood stem cell transplantation
- Author
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Ichiro Ito, Kentaro Miura, Hikaru Kobayashi, Yuta Nakano, Nobutaka Kobayashi, Nozomu Uematsu, and Toshimitsu Ueki
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Surgical resection ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Case Report ,General Medicine ,Hematopoietic stem cell transplantation ,medicine.disease ,Surgery ,Transplantation ,Lesion ,Leukemia ,Myelogenous ,medicine ,Peripheral Blood Stem Cell Transplantation ,medicine.symptom ,Pulmonary mucormycosis ,business - Abstract
Pulmonary mucormycosis is relatively rare and occurs in immunosuppressed patients, for example, individuals with hematologic malignancies such as leukemia. As pulmonary mucormycosis increases rapidly and is often fatal, appropriate treatment including surgical resection is necessary. We report a patient with pulmonary mucormycosis and acute myelogenous leukemia for which antifungal drugs were invalid. After rapid surgical resection, the patient was administered a peripheral blood stem cell transplantation. In conclusion, we emphasize that patients with pulmonary mucormycosis undergoing leukemia treatment should be considered for rapid surgical treatment if the infected lesion is limited, as overcoming this acute infection increases their chance to undergo hematopoietic stem cell transplantation and potential for long-term survival.
- Published
- 2019
150. STAT3 Mutations and Anemia with Pure Red Cell Aplasia Are the Distinctive Features of T Cell Receptor Gamma Delta Type Large Granular Lymphocyte Leukemia
- Author
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Yumiko Higuchi, Kaoko Sakai, Hideyuki Nakazawa, Kazuo Oshimi, Nodoka Sekiguchi, Hikaru Kobayashi, Taku Yamane, Jun Kobayashi, Hitoshi Sakai, Toru Kawakami, Toshimitsu Ueki, Fumihiro Ishida, and Sayaka Nishina
- Subjects
business.industry ,Large granular lymphocytic leukemia ,Immunology ,Pure red cell aplasia ,Lymphoproliferative disorders ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,Lymphoma ,Leukemia ,Cyclosporin a ,medicine ,T-cell lymphoma ,Enteropathy-associated T-cell lymphoma ,business - Abstract
Large granular lymphocytic leukemia (LGLL) is a heterogenous group of disorders. The clinical presentations of LGLL are highly variable; it may present with neutropenia or anemia, complicated with recurrent infections, autoimmune diseases such as rheumatoid arthritis, and neurological symptoms, requiring therapeutic interventions. It may present only with indolent laboratory changes without any symptoms. The cytological phenotypes of LGLL also vary and they commonly include CD8+TCR αβ-type, CD4+TCR αβ-type, and NK cell-type. NK cell-type LGLL is designated as chronic lymphoproliferative disorder of NK cells (CLPD-NK). TCR γδ-type LGLL (γδT-LGLL) is even rarer and it often confers cytopenia. The genetic backgrounds of LGLL with CD8+TCRαβ-type, CD4+TCRαβ-type and NK cell-type have been elucidated with the recent sequencing technologies. JAK/STAT signaling genes and chromatin-modifying genes were frequently mutated in the non-leukemic counterpart of the lymphoid malignancies with γδ TCR immunophenotypes, such as hepatosplenic T-cell lymphoma, monomorphic epitheliotropic intestinal T-cell lymphoma and primary cutaneous gamma delta T-cell lymphoma. However, the genetic basis of γδT-LGLL and the genetic-phenotypic associations remain unclear. The aim of this study is to identify clinical and genetic characteristics of γδT-LGLL in comparison with other LGL leukemias. In total, 56 LGLL patients were recruited; six patients with γδT-LGLL, 25 CD8+ TCRαβ type, 8 CD4+TCR αβ type and 17 CLPD-NK, in this study. All cases were negative for EBV. The median age of patients with γδT-LGLL was 48 years old and five of them were male. The median LGL counts and hemoglobin level were 1.81 ×109/L (range; 0.60-4.42) and 5.8 g/dL (range; 3.0-11.2), respectively. All patients with γδT-LGLL had anemia and/or neutropenia, although no patients were thrombocytopenic. 4 patients presented with pure red cell aplasia. Common immunophenotypes of γδT cells were CD2+ CD3+ CD4-CD7+. 3 patients were CD8+. CD16, CD56 and CD57 were positive in 3, 0, and 1 patient, respectively. γδT cells of all patients showed a monoclonal pattern of TCRγ gene rearrangements with BioMed 2 protocol. We performed amplicon sequencing of entire coding regions of STAT3, STAT5B and TNFAIP3 genes and allele-specific PCR for several hot spot regions of STAT3 and STAT5B genes using extracted DNA from mononuclear cells of peripheral blood. Mutations in STAT3 and TNFAIP3 were identified in 100% (6/6) and 17% (1/6), respectively. Among the10 STAT3 mutations identified, 5 were located in the SH-2 domain, while other 3 were in coiled-coiled domain and the other 2 were in the DNA binding domain. The median variant allele frequencies of STAT3 was 2.0% (0.7-22.6) and STAT3 mutations were restricted to sorted γδT cells in all 3 patients examined. No patient was positive for STAT5B mutations, including N642H and Y665F with allele specific PCRs. One of 5 patients who were treated with cyclosporin A was refractory. Two patients were treated with cyclophosphamide, showing clinical improvements. The patients with γδT-LGLL were younger than those with other types of LGLL (P=0.048) and anemia and STAT3 mutations were significantly more frequent in γδT-LGLL (P value; 0.003 and 0.02, respectively). PRCA was a consistent cause of anemia in γδT-LGLL. Low frequency of STAT5B mutations among γδT-LGLL patients was in contrast to other aggressive γδT cell lymphoma in which STAT5B frequently mutated. The clinical characteristics of γδT-LGLL patients may be defined by younger age and the anemia due to pure red cell aplasia, and the frequent STAT3 mutations might be a novel molecular marker for γδT-LGLL. Disclosures Yamane: Pfizer: Research Funding; Celgene: Honoraria; Bristol-Meyers Squibb: Research Funding; Chugai Pharmaceutical: Consultancy, Research Funding; Astellas Pharma: Research Funding; Eli Lily and Company: Research Funding. Ishida:Eli Lily and Company: Research Funding; Astellas Pharma: Research Funding; Pfizer: Research Funding; Bristol-Meyers Squibb: Research Funding; Chugai Pharmaceutical: Consultancy, Research Funding; Celgene: Honoraria.
- Published
- 2019
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