134 results on '"N. Osakabe"'
Search Results
2. 25-hydroxyvitamin D3 may Function via Genomic and Non-Genomic actions
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Y, Hirota, primary, Y, Suhara, additional, N, Osakabe, additional, T, Sakaki, additional, and T, Okano, additional
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- 2017
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3. Electron holography available in a non-biprism transmission electron microscope
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Q. Ru, N. Osakabe, J. Endo, and A. Tonomura
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Conventional transmission electron microscope ,Materials science ,business.industry ,Low-voltage electron microscope ,Holography ,Atomic and Molecular Physics, and Optics ,Electron holography ,Electronic, Optical and Magnetic Materials ,law.invention ,Optics ,Electron tomography ,law ,Scanning transmission electron microscopy ,Energy filtered transmission electron microscopy ,Electron beam-induced deposition ,business ,Instrumentation - Abstract
A method for taking electron holograms with a single crystal instead of an electron biprism is described. The method is so simple that only a single crystal needs to be placed on the specimen grid in the specimen holder. Then, the crystal lattice fringes are focused on the recording photographic film to form an off-axis Fresnel hologram. The procedures for both hologram formation and reconstruction are described. Experimental results show that holograms can also be achieved with a conventional transmission electron microscope having a low-coherence electron source.
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- 1994
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4. Small angle electron diffraction and Foucault mode Lorentz microscopy of superconducting vortex lattice
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T. Yoshida, J. Endo, H. Kasai, K. Harada, N. Osakabe, T. A. Tonomura, and G. Pozzi
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Diffraction ,Physics ,Reflection high-energy electron diffraction ,Condensed matter physics ,Electron diffraction ,Condensed Matter::Superconductivity ,General Physics and Astronomy ,Diffraction topography ,Selected area diffraction ,Kikuchi line ,Powder diffraction ,Electron backscatter diffraction - Abstract
Small angle electron diffraction patterns from vortex lattices in Nb thin films were observed using a field emission transmission electron microscope. It was possible to obtain diffraction patterns in magnetic fields of up to 1000 G, from selected areas of (1–10) μm in diameter, and in (1–30) s. The degree of order of the vortex lattice was determined from the fine structure of the diffraction pattern. We also demonstrated Foucault mode Lorentz microscopy by using a diffraction technique. Vortices appeared by diffraction contrast in a focused micrograph, and therefore both vortices and material defects were simultaneously observed.
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- 1999
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5. Quantitative analysis of amyloid plaques in a mouse model of Alzheimer's disease by phase-contrast X-ray computed tomography
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Tohoru Takeda, Akio Yoneyama, Yoshitsugu Shitaka, Masamichi Okada, K. Terai, Kyoko Noda-Saita, Jin Wu, N. Osakabe, Kazuyuki Hyodo, T. Yamaguchi, and Yasuharu Hirai
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Pathology ,medicine.medical_specialty ,Aging ,Amyloid ,Mice, Transgenic ,Plaque, Amyloid ,Disease ,Pathogenesis ,Central nervous system disease ,Mice ,Degenerative disease ,Alzheimer Disease ,Predictive Value of Tests ,mental disorders ,medicine ,Neurites ,Animals ,Microscopy, Phase-Contrast ,Cerebral Cortex ,Amyloid beta-Peptides ,Chemistry ,General Neuroscience ,medicine.disease ,Peptide Fragments ,Disease Models, Animal ,Female ,Tomography ,Molecular imaging ,Alzheimer's disease ,Tomography, X-Ray Computed - Abstract
Densely aggregated beta-amyloid peptides are believed to play a key role in the pathogenesis of Alzheimer's disease. Amyloid plaques are a potential target for molecular imaging to determine the clinical status of Alzheimer's disease. Phase-contrast X-ray imaging combined with computed tomography is a promising technique that can be used to visualize the physical density of structures in biological tissues non-invasively, and without the use of imaging agents. Using brain tissue isolated from a mouse model of Alzheimer's disease, we show that beta-amyloid 40-positive/beta-amyloid 42-positive amyloid plaques, but not beta-amyloid 40-negative/beta-amyloid 42-positive amyloid plaques, exist as high-density aggregates that can be specifically detected by phase-contrast X-ray computed tomography. The phase-contrast X-ray computed tomography detected beta-amyloid 40-positive/beta-amyloid 42-positive amyloid plaques in three-dimensions with an extremely high sensitivity comparable to that of histological analysis, and also enabled the load of amyloid plaques to be quantified. Furthermore, the use of phase-contrast X-ray computed tomography reveals that the physical density of beta-amyloid 40-positive/beta-amyloid 42-positive amyloid plaques increases with age, and that the large volume, high-density, amyloid plaques that are specifically observed in aged Alzheimer's disease mice are closely associated with neuritic dystrophy. These results demonstrate that phase-contrast X-ray computed tomography is a highly sensitive imaging technique for analyzing dense-cored amyloid plaques in postmortem samples, and is beneficial in elucidating amyloid pathophysiology in Alzheimer's disease.
- Published
- 2005
6. Surface acoustic wave linear motor using silicon slider
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Toshiro Higuchi, O. Shinoura, Minoru Kurosawa, and N. Osakabe
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Transducer ,Traverse ,Materials science ,Slider ,Acoustics ,Surface acoustic wave ,Friction drive ,Surface acoustic wave sensor ,Linear motor ,Contact area - Abstract
Using a silicon fabricated slider, the output force and the maximum traverse velocity of a surface acoustic wave motor has been improved up to 12 times larger force and twice faster speed than the previous motor which used a multi contact points slider. To obtain the high output force, large contact area between the slider and the stator transducer is required. Therefore a silicon slider was developed and tested. As a result, the maximum output force of 3.5 N and the maximum traverse velocity of 0.65 m/s were obtained. The maximum output force of 3.5 N was 90 times of the transducer weight. Such a high output force performance is produced by high power density of surface acoustic wave devices and friction drive.
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- 2002
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7. Miniaturization of surface acoustic wave linear motor
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Masaya Takasaki, Minoru Kurosawa, N. Osakabe, and Toshiro Higuchi
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Physics ,Transducer ,Surface wave ,business.industry ,Ultrasonic motor ,Acoustics ,Surface acoustic wave ,Electrical engineering ,Miniaturization ,Acoustic wave ,Linear motor ,business ,Voltage - Abstract
This paper describes the way of a miniaturization of a surface acoustic wave (SAW) linear motor and the first success of driving the miniaturized SAW linear motor. A problem which occurs with the miniaturization of the motor is also mentioned. The motor was operated at 50 MHz. The miniaturized motor could work at 0.7 m/s.
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- 2002
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8. New Applications and Analysis of Avalanche Photodiodes as Detectors for Electrons Ranging from 10 KeV to 300 KeV
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T. Kodama, N. Osakabe, J. Endo, A. Tonomura, T. Urakami, S. Ohsuka, H. Tsuchiya, and Y. Tsuchiya
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Materials science ,Physics::Instrumentation and Detectors ,business.industry ,law ,Detector ,Optoelectronics ,Ranging ,Electron ,business ,Avalanche photodiode ,Silicon avalanche photodiodes ,Photodiode ,law.invention - Abstract
New applications of avalanche photodiodes as fast timing detectors for electrons ranging from 10 keV to 300 keV together with an analysis of the response of silicon avalanche photodiodes to the electrons are reported.
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- 1997
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9. Electron Microscopy Study on Magnetic Flux Lines in Superconductors: Memorial to Akira Tonomura
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N. Osakabe, Y. A. Ono, and K. Harada
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Superconductivity ,Physics ,High-temperature superconductivity ,Condensed matter physics ,Niobium ,chemistry.chemical_element ,Electron ,Condensed Matter Physics ,Magnetic flux ,Electron holography ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry ,law ,Condensed Matter::Superconductivity ,Electrical and Electronic Engineering ,Electron microscope ,Optical vortex - Abstract
Using electron holography and coherent beam Lorentz microscopy, Akira Tonomura investigated the physics of magnetic flux lines, or vortices, in metal and high-temperature superconductors for more than 20 years. The methodology he developed for doing this made use of coherent electron waves from cold-emission (field-emission) sources and their quantum-mechanical phase shifts. Using 300-kV and 1-MV electron microscopes, Tonomura and his team clarified the dynamic behavior of magnetic flux lines in Pb and Nb superconductors and in high-temperature YBa2Cu3O7-δ and Bi2Sr2CaCu2O8 + δ superconductors. This memorial paper reviews the static and dynamic flux-line behaviors in superconductors as revealed by their results.
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- 2013
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10. Development of a Direction-Free Magnetic Field Application System
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K. Harada, J. Endo, N. Osakabe, A. Tonomura, and K. Kitazawa
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Physics ,Development (differential geometry) ,Instrumentation ,Engineering physics ,Magnetic field - Published
- 2002
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11. Development of a 1MV-Field-Emission Electron Microscope I. Instrument
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I. Matsui, T. Katsuta, T. Kawasaki, S. Hayashi, T. Furutsu, T. Onai, K. Myochin, T. Yoshida, T. Matsuda, S. Kubota, J. Endo, N. Osakabe, A. Tonomura, and K . Kitazawa
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Materials science ,business.industry ,Acceleration voltage ,Electron holography ,law.invention ,Field electron emission ,Optics ,Transmission electron microscopy ,law ,Scanning transmission electron microscopy ,Cathode ray ,Electron microscope ,business ,Instrumentation ,Beam (structure) - Abstract
We have developed 100-kV, 200-kV, and 350-kV cold-field-emission transmission electron microscopes (FE-TEMs) successively up to this time. Using these instruments, we have been studying the magnetic structure of materials, high-resolution imaging by electron holography, and dynamic observation of the vortex in superconductors by Lorentz microscopy. To make more progress in our research, we need a better electron beam in terms of coherency, beam brightness, and penetration. Here, we report a new lMV-cold-field-emission transmission electron microscope we have developed. Historically, the pioneering projects on a lMV-field-emission scanning transmission electron microscope (FE-STEM) (Zeitler and Crewe, 1974) and a 1.6MV FE-STEM (Jouffrey et al., 1984) have been reported. In 1988, Maruse and Shimoyama obtained a lMV-field-emission beam using their 1.25MV-STEM connected to a field-emission gun. Since then, continuous improvements in beam brightness has been made.The target specifications of our 1 MV-cold-field-emission TEM (H-1000FT) are as follows: Acceleration voltage: 1MV, high-voltage stability
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- 2000
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12. Electron holography of frozen-hydrated biological specimens
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T. Matsumoto, N. Osakabe, J. Endo, T. Matsuda, and A. Tonomura
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Frozen hydrated ,Biological specimen ,Materials science ,Analytical chemistry ,General Medicine ,Electron holography - Abstract
Electron holography has been applied to a variety of field, in which the reconstructed phase information was effectively used to elucidate many important natures of materials. Applications of electron holography to biological specimen, however, has not been developed yet. We report here an application of electron holography of frozen-hydrated biological specimen, which is observed by electron holography for the first time.An electron microscope(Hitachi HU-12A) equipped with a 100-kV cold field emission gun was used for the experiment. Catalase crystals were embedded in amorphous ice by quick-freezing and the grids were transferred to the microscope using Gatan cryo transfer system. A specially designed low-dose imaging system for the microscope was devised and used to record holograms.
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- 1991
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13. Observation of Single Magnetic-Flux Quanta Using Electron Holography
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T. Matsuda, S. Hasegawa, J. Endo, N. Osakabe, A. Tonomura, and R. Aoki
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Physics ,General Medicine ,Atomic physics ,Electron holography ,Magnetic flux - Abstract
A Magnetic flux quantum (fluxon) penetrating a superconductor plays an important role in both fundamental and practical applications of superconductivity. However, the fluxon has evaded direct observation, because it is shaped like an extremely thin filament in addition to its small flux value, h/2e (=2x10−15Wb). Several methods have already been developed to indirectly observe each filament of flux. One method is Bitter's [1], in which magnetic powder is sprinkled on the superconductor surface. The powder accumulates at the fluxons, and the image is observed by electron microscopy.We have observed the magnetic field of a single fluxon using holographic electron interferometry [2], in which the phase distribution of an electron beam can be measured to a precision of 2Π/50. The schematic diagram of the experiment is shown in Fig. 1. A weak magnetic field is applied perpendicularly to a superconducting lead film. Fiuxons penetrating the film are observed as phase contour fringes through the electron holography process. The sample is prepared by evaporating lead on one side of a thin tungsten wire, which is shown in Fig. 2.
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- 1990
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14. Observation of recorded magnetization patterns by electron holography
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H. Tanabe, A. Tonomura, T. Matsuda, Kazuetsu Yoshida, Hideo Fujiwara, T. Okuwaki, Kiminari Shinagawa, N. Osakabe, and Y. Horiuchi
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Materials science ,Condensed matter physics ,Holography ,Coercivity ,Magnetic flux ,Electron holography ,Electronic, Optical and Magnetic Materials ,law.invention ,Magnetization ,Vacuum deposition ,Remanence ,law ,Electrical and Electronic Engineering ,Thin film - Abstract
Magnetization patterns recorded on Co thin films prepared by oblique incidence vacuum deposition were directly observed by electron holography. Complicated ellipse-like interference fringes were observed along the sawtooth-like walls in the transition regions. Stray magnetic flux was observed in empty space beyond the edge of the film. The following results were obtained from analysis of these interference images. The smaller the product of the remanence and the film thickness, and the higher the coercivity, the narrower is the transition length that determines the limit of the recording density of a medium. It was confirmed that longitudinal magnetic recording of a density of up to 170 kBPI is attainable using Co film 30 nm thick and with coercivity of 112 kA/m. It was quantitatively proven that the intensity of the recorded magnetization in a medium is equal to its remanence when the magnetized area is distinguishable from the transition region.
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- 1983
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15. Surface study by an UHV electron microscope
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K. Yagi, Goro Honjo, Kunio Takayanagi, Yasumasa Tanishiro, N. Osakabe, and Kunio Kobayashi
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Surface (mathematics) ,Materials science ,law ,Materials Chemistry ,Surfaces and Interfaces ,Electron beam-induced deposition ,Electron microscope ,Condensed Matter Physics ,Molecular physics ,Superstructure (condensed matter) ,Surfaces, Coatings and Films ,law.invention - Abstract
An anomalous surface superstructure along 〈110〉 of a clean (111)Au surface and two-dimensional nucleus formation of Pd on an atomically flat (111)Ag surface have been observed by an UHV electron microscope.
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- 1979
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16. Caffeinated Beverages
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THOMAS H. PARLIMENT, CHI-TANG HO, PETER SCHIEBERLE, D. G. Steffen, George R. Waller, Hiroshi Ashihara, Misako Kato, Thomas W. Baumann, Alan Crozier, Takeo Suzuki, Stanley Segall, Andrew Smith, Carolyn Brice, Peter J. Rogers, Astrid Nehlig, E. G. Miller, A. P. Gonzales, A. M. Orr, W. H. Binnie, G. I. Sunahara, Andrew Sivak, Richard H. Adamson, Jen-Kun Lin, Yu-Chih Liang, Yu-Li Lin, N. Osakabe, M. Yamagishi, M. Natsume, T. Takizawa, T. Nakamura, T. Osawa, M. Richelle, T. Huynh-Ba, I. Tavazzi, V. Mooser, M. Enslen, E. A. Offord, Ulrich H. Engelhardt, Christiane Lakenbrink, Svenja Lapczynski, K. Bungert, K. Eichner, K. G. Lee, H. Aoki, T. Shibamoto, Masayuki Suzuki, Masao Mori, Fumio Nanjo, Yukihiko Hara, Zhen-Yu Chen, Wing Ping Fong, Monica M. Bearden, Debra A. Pearson, Dietrich Rein, Kati A. Chevaux, Dana R. Carpenter, Carl L. Keen, Harold Schmitz, W. Grosch, M. Czerny, F. Mayer, A. Moors, George P. Rizzi, Y. S. Ko, I. Blank, E. C. Pascual, L. B. Fay, R. H. Stadler, B. A. Goodman, C. Yeretzian, K. Speer, A. Hruschka, T. Kurzrock, I. Kölling-Speer, H. Steinhart, THOMAS H. PARLIMENT, CHI-TANG HO, PETER SCHIEBERLE, D. G. Steffen, George R. Waller, Hiroshi Ashihara, Misako Kato, Thomas W. Baumann, Alan Crozier, Takeo Suzuki, Stanley Segall, Andrew Smith, Carolyn Brice, Peter J. Rogers, Astrid Nehlig, E. G. Miller, A. P. Gonzales, A. M. Orr, W. H. Binnie, G. I. Sunahara, Andrew Sivak, Richard H. Adamson, Jen-Kun Lin, Yu-Chih Liang, Yu-Li Lin, N. Osakabe, M. Yamagishi, M. Natsume, T. Takizawa, T. Nakamura, T. Osawa, M. Richelle, T. Huynh-Ba, I. Tavazzi, V. Mooser, M. Enslen, E. A. Offord, Ulrich H. Engelhardt, Christiane Lakenbrink, Svenja Lapczynski, K. Bungert, K. Eichner, K. G. Lee, H. Aoki, T. Shibamoto, Masayuki Suzuki, Masao Mori, Fumio Nanjo, Yukihiko Hara, Zhen-Yu Chen, Wing Ping Fong, Monica M. Bearden, Debra A. Pearson, Dietrich Rein, Kati A. Chevaux, Dana R. Carpenter, Carl L. Keen, Harold Schmitz, W. Grosch, M. Czerny, F. Mayer, A. Moors, George P. Rizzi, Y. S. Ko, I. Blank, E. C. Pascual, L. B. Fay, R. H. Stadler, B. A. Goodman, C. Yeretzian, K. Speer, A. Hruschka, T. Kurzrock, I. Kölling-Speer, and H. Steinhart
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- 2000
17. Applications of holographic interference electron microscopy to the observation of biological specimens
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T, Kawasaki, J, Endo, T, Matsuda, N, Osakabe, and A, Tonomura
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Microscopy, Electron ,Protein Conformation ,Ferritins ,Holography - Published
- 1986
18. Investigation of biogenic magnetite particles by high-resolution electron microscope
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T. Matsuda, J. Endo, N. Osakabe, A. Tonomura, and T. Arii
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chemistry.chemical_compound ,Materials science ,chemistry ,Analytical chemistry ,General Medicine ,High resolution electron microscope ,Magnetite - Abstract
In 1975, Blakemore found aquatic bacteria that swim along earth's magnetic lines of force [1]. They have permanent magnets of iron-rich fine particles within them. Such particles were found by Mössbauer analysis to consist of magnetite in the case of magnetospirilla [2]. In addition, Towe et al confirmed by electron diffraction that the particles were crystalline [3]. The purpose of the present investigation is to determine the crystal and magnetic structure of these particles by both high-resolution lattice imaging and electron holography; however only the former is reported here.Magnetotactic bacteria were gathered in a fresh-water pond. The specimens were peanut-shaped, and approximately 3um in length. Transmission electron micrographs, such as that shown in Fig. 1, reveal that approximately 30 fine particles are aligned within each bacterium.
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- 1984
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19. Observation of surface morphology by reflection electron holography
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N. Osakabe, J. Endo, T. Matsuda, and A. Tonomura
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Surface (mathematics) ,Materials science ,Optics ,Morphology (linguistics) ,business.industry ,Reflection (physics) ,General Medicine ,business ,Electron holography - Abstract
Progress in microscopy such as STM and TEM-TED has revealed surface structures in atomic dimension. REM has been used for the observation of surface dynamical process and surface morphology. Recently developed reflection electron holography, which employes REM optics to measure the phase shift of reflected electron, has been proved to be effective for the observation of surface morphology in high vertical resolution ≃ 0.01 Å.The key to the high sensitivity of the method is best shown by comparing the phase shift generation by surface topography with that in transmission mode. Difference in refractive index between vacuum and material Vo/2E≃10-4 owes the phase shift in transmission mode as shownn Fig. 1( a). While geometrical path difference is created in reflection mode( Fig. 1(b) ), which is measured interferometrically using high energy electron beam of wavelength ≃0.01 Å. Together with the phase amplification technique , the vertivcal resolution is expected to be ≤0.01 Å in an ideal case.
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- 1989
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20. Surface study by UHV electron microscope
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G. Honjo, Kunio Kobayashi, Y. Tanishiro, K. Takayanagi, K. Yagi, and N. Osakabe
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Surface (mathematics) ,Materials science ,business.industry ,law ,Optoelectronics ,General Medicine ,Electron microscope ,business ,law.invention - Abstract
Recent advances of UHV techniques, LEED, RHEED and AES, arose a surge of interest on the surface of solids. These techniques reveal structures and chemical compositions at the mono-atomic or mono-molecular level. All of them, however, are devoid of detailed topographic informations, although some efforts to introduce the scanning techniques have been done[l]. Transmission electron microscopy of high resolution should play a complementary role to these techniques. No attempt, however, has been done previously to use it to such a purpose. This was because it was difficult to get and keep clean surfaces in the poor vacuum at 1x10-5Torr level of the conventional electron microscope.The present paper reports observations of surface phenomena of one or two atomic layer level using a UHV JEM 100B electron microscope (10-8-10-10Torr), recently developed for insitu thin film growth studies[2]. Atomically flat (111) surfaces of Ag, Pd, Au and Cu were prepared by in- situ deposition at 150-350°C on M0S2, graphite and MgO. Air Cleaved thin films of MoS2 and graphite were preheated to 800°C to get clean surfaces[3].
- Published
- 1978
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21. Reflection electron microscopy of clean and gold deposited (111) silicon surfaces
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N. Osakabe, Goro Honjo, K. Yagi, and Yasumasa Tanishiro
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Diffraction ,Materials science ,Silicon ,business.industry ,Ultra-high vacuum ,chemistry.chemical_element ,Surfaces and Interfaces ,Condensed Matter Physics ,law.invention ,Surfaces, Coatings and Films ,Monatomic ion ,Reflection (mathematics) ,Optics ,chemistry ,law ,Thermal ,Materials Chemistry ,Optoelectronics ,Electron microscope ,business ,Deposition (law) - Abstract
Reflection electron microscopy in ultra high vacuum has been performed during the process of thermal cleaning which converts the dirty (111) silicon surface of the 1 × 1 structure to the clean surface of the 7 × 7 structure, and during the transformations of the 7 × 7 structure to the 5 × 1, √3 × √3 and 6 × 6 structures produced by deposition of gold up to a few monatomic layers. The reflection images showed the microtopographical aspects of the process and of the transformations to be in close correlation with the structural information given by the reflection diffraction patterns observed simultaneously.
- Published
- 1980
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22. Sensitivity-Enhanced Interference Electron Microscopy
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N. Osakabe, J. Endo, T. Matsuda, T. Kawasaki, and A. Tonomura
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Materials science ,Interference (communication) ,law ,business.industry ,Optoelectronics ,General Medicine ,Sensitivity (control systems) ,Electron microscope ,business ,law.invention - Abstract
Interference electron microscopy by holographic reconstruction has been applied to many fields: An interferogram of a specimen having nonunifom thickness can be interpreted as a thickness contour map. In case of a ferromagnetic thin film, contour lines in an interferogram follow the magnetic lines of force. The contour interval of a phase-shift ƛ (ƛ is an electron wave length) correspons to a thickness of 2 ϕ0 ƛ/V0 (V0 is the mean inner potential and ϕ0 is the accererlating voltage) and a magnetic flux of h/e (= 4.1X10—15 Wb) respectively. For detailed observation such as that of atomic scale thickness variation or weak magnetic fields from single domain fine particles, electron phase shifts recorded in a hologram has to be amplified. In recent experiment conducted by authors, interferograms phase amplified 10 times were obtained. The method employed a higher-order diffracted beam and its conjugate utilizing the film's nonlineality. However the phase amplification of factor 10 is not sufficient for the above purposes. In the present experiment, successful attempt to detect an electron phase shift of order ƛ /100 was made using another phase-amplification technique introduced by Bryngdahl and improved by Matsuda.
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- 1985
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23. Development of low temperature specimen stage and its applications to electron holographic measurement
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J. Endo, N. Osakabe, T. Matsuda, S. Yano, H. Yamada, T. Kawasaki, and A. Tonomura
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Materials science ,Optics ,law ,business.industry ,Condensed Matter::Superconductivity ,Quantitative Biology::Tissues and Organs ,Holography ,General Medicine ,Stage (hydrology) ,Electron ,business ,law.invention - Abstract
Using electron holography, information about a specimen, such as distributions of magnetization and thickness, can be revealed by investigating the shape of reconstructed wavefronts of the laser beam. These distinctive features can be utilized in investigations in the fields of superconductivity and biology. Therefore, we have developed a low temperature specimen stage which is reguired for superconducting specimens and to decrease the radiation damage in biological specimens. Using this cold stage, we have observed magnetic flux quantization in superconductors.
- Published
- 1986
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24. Direct observation of the phase transition between the (7 × 7) and (1 × 1) structures of clean (111) silicon surfaces
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N. Osakabe, Goro Honjo, Yasumasa Tanishiro, and K. Yagi
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Surface (mathematics) ,Phase transition ,Silicon ,Nucleation ,chemistry.chemical_element ,Surfaces and Interfaces ,Condensed Matter Physics ,Molecular physics ,Microscopic scale ,law.invention ,Surfaces, Coatings and Films ,Crystallography ,Reflection (mathematics) ,chemistry ,law ,Phase (matter) ,Materials Chemistry ,Electron microscope - Abstract
The phase transition process of clean (111) silicon surfaces between the (7 × 7) and (1 × 1) structures at about 830°C was directly observed by reflection electron microscopy, which had been briefly reported in a previous short communication (Osakabe et al., Japan. J. Appl. Phys, 19 (1980) L309). Smooth atomic steps, whose shapes change spontaneously and continually in a microscopic scale at high temperature of the (1 × 1) structure, transform into zig-zag steps at low temperature of the (7 × 7) structure, where the changes of the step shape stop. On cooling, domains of the (7 × 7) structure nucleate preferentially on upper terraces along the steps and expand on the terraces to the neighbouring steps. Out of phase boundaries with phase differences of 2πn/7 are seen to be formed. On heating the reversed process takes place. The out of phase boundaries are easy places to transform to the (1 × 1) structure. The observations clearly suggest the phase transition of the first order and the models of the (7 × 7) structure of ordered vacancies or adatoms rather than of static displacements of surface atoms.
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- 1981
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25. Change in Nfkb/Nrf2/Bax Levels by High Monomeric Polyphenols Berries Extract (HMPBE) in Acute and Chronic Secondary Brain Damage.
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Modafferi S, Molinari F, Interdonato L, Fusco R, Impellizzeri D, Siracusa R, D'Amico R, Abdelhameed AS, Wenzel U, Jacobs U, Fritsch T, Osakabe N, Cuzzocrea S, Calabrese V, Paola RD, and Cordaro M
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- Animals, Mice, Male, Brain Injuries, Traumatic metabolism, Brain Injuries, Traumatic drug therapy, Brain Injuries, Traumatic pathology, Disease Models, Animal, Tyrosine 3-Monooxygenase metabolism, Dopamine Plasma Membrane Transport Proteins metabolism, Apoptosis drug effects, Mice, Inbred C57BL, Brain metabolism, Brain drug effects, Brain pathology, Lipid Peroxidation drug effects, NF-E2-Related Factor 2 metabolism, Polyphenols pharmacology, Polyphenols chemistry, Polyphenols therapeutic use, NF-kappa B metabolism, Plant Extracts pharmacology, Plant Extracts chemistry, Fruit chemistry, bcl-2-Associated X Protein metabolism
- Abstract
Background/aims: High Monomeric Polyphenols Berries Extract (HMPBE) is a formula highly rich in polyphenols clinically proven to enhance learning and memory. It is currently used to enhances cognitive performance including accuracy, working memory and concentration., Methods: Here, we investigated for the first time the beneficial effects of HMPBE in a mouse model of acute and chronic traumatic brain injury (TBI)., Results: HMPBE, at the dose of 15 mg/kg was able to reduce histological alteration as well as inflammation and lipid peroxidation. HMPBE ameliorate TBI by improving Nrf-2 pathway, reducing Nf-kb nuclear translocation and apoptosis, and ameliorating behavioral alteration such as anxiety and depression. Moreover, in the chronic model of TBI, HMPBE administration restored the decline of Tyrosine Hydroxylase (TH) and dopamine transporter (DAT) and the accumulation of a-synuclein into the midbrain region. This finding correlates the beneficial effect of HMPBE administration with the onset of parkinsonism related to traumatic brain damage., Conclusion: The data may open a window for developing new support strategies to limit the neuroinflammation event of acute and chronic TBI., Competing Interests: The authors have no relevant financial or non-financial interests to disclose., (© Copyright by the Author(s). Published by Cell Physiol Biochem Press.)
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- 2024
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26. Transgenerational hormesis in healthy aging and antiaging medicine from bench to clinics: Role of food components.
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Calabrese V, Osakabe N, Siracusa R, Modafferi S, Di Paola R, Cuzzocrea S, Jacob UM, Fritsch T, Abdelhameed AS, Rashan L, Wenzel U, Franceschi C, and Calabrese EJ
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- Humans, Animals, Healthy Aging metabolism, Neurodegenerative Diseases metabolism, Neurodegenerative Diseases drug therapy, Hormesis
- Abstract
Neurodegenerative diseases have multifactorial pathogenesis, mainly involving neuroinflammatory processes. Finding drugs able to treat these diseases, expecially because for most of these diseases there are no effective drugs, and the current drugs cause undesired side effects, represent a crucial point. Most in vivo and in vitro studies have been concentrated on various aspects related to neurons (e.g. neuroprotection), however, there has not been focus on the prevention of early stages involving glial cell activation and neuroinflammation. Recently, it has been demonstrated that nutritional phytochemicals including polyphenols, the main active constituents of the Mediterranean diet, maintain redox balance and neuroprotection through the activation of hormetic vitagene pathway. Recent lipidomics data from our laboratory indicate mushrooms as strong nutritional neuronutrients with strongly activity against neuroinflammation in Meniere' diseaseas, a model of cochleovestibular neural degeneration, as well as in animal model of traumatic brain injury, or rotenone induced parkinson's disease. Moreover, Hidrox®, an aqueous extract of olive containing hydroxytyrosol, and Boswellia, acting as Nrf2 activators, promote resilience by enhancing the redox potential, and thus, regulate through hormetic mechanisms, cellular stress response mechanisms., Thus, modulation of cellular stress pathways, in particular vitagenes system, may be an innovative approach for therapeutic intervention in neurodegenerative disorders., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest., (Copyright © 2024. Published by Elsevier B.V.)
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- 2024
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27. Investigating hormesis, aging, and neurodegeneration: From bench to clinics.
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Calabrese V, Wenzel U, Piccoli T, Jacob UM, Nicolosi L, Fazzolari G, Failla G, Fritsch T, Osakabe N, and Calabrese EJ
- Abstract
Mitochondria-derived reactive oxygen species production at a moderate physiological level plays a fundamental role in the anti-aging signaling, due to their action as redox-active sensors for the maintenance of optimal mitochondrial balance between intracellular energy status and hormetic nutrients. Iron regulatory protein dysregulation, systematically increased iron levels, mitochondrial dysfunction, and the consequent oxidative stress are recognized to underlie the pathogenesis of multiple neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. Central to their pathogenesis, Nrf2 signaling dysfunction occurs with disruption of metabolic homeostasis. We highlight the potential therapeutic importance of nutritional polyphenols as substantive regulators of the Nrf2 pathway. Here, we discuss the common mechanisms targeting the Nrf2/vitagene pathway, as novel therapeutic strategies to minimize consequences of oxidative stress and neuroinflammation, generally associated to cognitive dysfunction, and demonstrate its key neuroprotective and anti-neuroinflammatory properties, summarizing pharmacotherapeutic aspects relevant to brain pathophysiology., Competing Interests: Conflict of interest: Vittorio Calabrese serves as Editor in Chief of Open Medicine, but it did not influenced peer-review process. Authors state no conflict of interest., (© 2024 the author(s), published by De Gruyter.)
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- 2024
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28. Frankincense: A neuronutrient to approach Parkinson's disease treatment.
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Calabrese V, Osakabe N, Khan F, Wenzel U, Modafferi S, Nicolosi L, Fritsch T, Jacob UM, Abdelhameed AS, and Rashan L
- Abstract
Parkinson's disease (PD), characterized by tremor, slowness of movement, stiffness, and poor balance, is due to a significant loss of dopaminergic neurons in the substantia nigra pars compacta and dopaminergic nerve terminals in the striatum with deficit of dopamine. To date the mechanisms sustaining PD pathogenesis are under investigation; however, a solid body of experimental evidence involves neuroinflammation, mitochondrial dysfunction, oxidative stress, and apoptotic cell death as the crucial factors operating in the pathogenesis of PD. Nutrition is known to modulate neuroinflammatory processes implicated in the pathogenesis and progression of this neurodegenerative disorder. Consistent with this notion, the Burseraceae family, which includes the genera Boswellia and Commiphora , are attracting emerging interest in the treatment of a wide range of pathological conditions, including neuroinflammation and cognitive decline. Bioactive components present in these species have been shown to improve cognitive function and to protect neurons from degeneration in in vitro , animal, as well as clinical research. These effects are mediated through the anti-inflammatory, antiamyloidogenic, anti-apoptotic, and antioxidative properties of bioactive components. Although many studies have exploited possible therapeutic approaches, data from human studies are lacking and their neuroprotective potential makes them a promising option for preventing and treating major neurodegenerative disorders., Competing Interests: Conflict of interest: Vittorio Calabrese serves as Editor in Chief for Open Medicine, but it did not influenced peer-review process. The authors declare that they have no conflicts of interest., (© 2024 the author(s), published by De Gruyter.)
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- 2024
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29. Procyanidins and sensory nutrition; do procyanidins modulate homeostasis via astringent taste receptors?
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Osakabe N, Fushimi T, Fujii Y, and Calabrese V
- Subjects
- Astringents pharmacology, Taste, Homeostasis, Proanthocyanidins pharmacology, Taste Buds
- Abstract
Long-term intake of procyanidins has been suggested to reduce the risk of cardiovascular disease, dementia, and sensory function decline associated with aging. However, most of the ingested procyanidins are not absorbed and are excreted in the feces, so the mechanism of their beneficial impact is unknown. Procyanidins are the components of astringency in plant foods and their stimulation appears to be directly transmitted to the central nervous system via sensory nerves. Recent attention has been focused on the taste receptors expressed in the extra-oral gastrointestinal tract may regulate homeostasis via the neuroendocrine system. In this paper, we have reviewed recent findings on the relationship between the astringency of procyanidins and their bioregulatory effects., (© The Author(s) 2023. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)
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- 2024
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30. Sensory Nutrition and Bitterness and Astringency of Polyphenols.
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Osakabe N, Shimizu T, Fujii Y, Fushimi T, and Calabrese V
- Subjects
- Astringents pharmacology, Diet, Nutritional Status, Polyphenols pharmacology, Taste
- Abstract
Recent studies have demonstrated that the interaction of dietary constituents with taste and olfactory receptors and nociceptors expressed in the oral cavity, nasal cavity and gastrointestinal tract regulate homeostasis through activation of the neuroendocrine system. Polyphenols, of which 8000 have been identified to date, represent the greatest diversity of secondary metabolites in plants, most of which are bitter and some of them astringent. Epidemiological studies have shown that polyphenol intake contributes to maintaining and improving cardiovascular, cognitive and sensory health. However, because polyphenols have very low bioavailability, the mechanisms of their beneficial effects are unknown. In this review, we focused on the taste of polyphenols from the perspective of sensory nutrition, summarized the results of previous studies on their relationship with bioregulation and discussed their future potential.
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- 2024
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31. Redoxomics in Ageing and Neurodegenerative Disorders: From Bench to Clinics.
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Calabrese V, Jacob UM, Fritsch T, Abdelhameed AS, and Osakabe N
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- 2023
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32. Polyphenols in Inner Ear Neurobiology, Health and Disease: From Bench to Clinics.
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Osakabe N, Modafferi S, Ontario ML, Rampulla F, Zimbone V, Migliore MR, Fritsch T, Abdelhameed AS, Maiolino L, Lupo G, Anfuso CD, Genovese E, Monzani D, Wenzel U, Calabrese EJ, Vabulas RM, and Calabrese V
- Subjects
- Humans, Polyphenols pharmacology, Polyphenols therapeutic use, Cochlea, Aging physiology, Neurobiology, Deafness
- Abstract
There is substantial experimental and clinical interest in providing effective ways to both prevent and slow the onset of hearing loss. Auditory hair cells, which occur along the basilar membrane of the cochlea, often lose functionality due to age-related biological alterations, as well as from exposure to high decibel sounds affecting a diminished/damaged auditory sensitivity. Hearing loss is also seen to take place due to neuronal degeneration before or following hair cell destruction/loss. A strategy is necessary to protect hair cells and XIII cranial/auditory nerve cells prior to injury and throughout aging. Within this context, it was proposed that cochlea neural stem cells may be protected from such aging and environmental/noise insults via the ingestion of protective dietary supplements. Of particular importance is that these studies typically display a hormetic-like biphasic dose-response pattern that prevents the occurrence of auditory cell damage induced by various model chemical toxins, such as cisplatin. Likewise, the hormetic dose-response also enhances the occurrence of cochlear neural cell viability, proliferation, and differentiation. These findings are particularly important since they confirmed a strong dose dependency of the significant beneficial effects (which is biphasic), whilst having a low-dose beneficial response, whereas extensive exposures may become ineffective and/or potentially harmful. According to hormesis, phytochemicals including polyphenols exhibit biphasic dose-response effects activating low-dose antioxidant signaling pathways, resulting in the upregulation of vitagenes, a group of genes involved in preserving cellular homeostasis during stressful conditions. Modulation of the vitagene network through polyphenols increases cellular resilience mechanisms, thus impacting neurological disorder pathophysiology. Here, we aimed to explore polyphenols targeting the NF-E2-related factor 2 (Nrf2) pathway to neuroprotective and therapeutic strategies that can potentially reduce oxidative stress and inflammation, thus preventing auditory hair cell and XIII cranial/auditory nerve cell degeneration. Furthermore, we explored techniques to enhance their bioavailability and efficacy.
- Published
- 2023
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33. Exploring Novel Vitamin K Derivatives with Anti-SARS-CoV-2 Activity.
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Homma T, Okamoto M, Koharazawa R, Hayakawa M, Fushimi T, Tode C, Hirota Y, Osakabe N, Baba M, and Suhara Y
- Abstract
From our compound library of vitamin K derivatives, we found that some compounds exhibited anti-SARS-CoV-2 activity in VeroE6/TMPRSS2 cells. The common structure of these compounds was menaquinone-2 (MK-2) with either the m -methylphenyl or the 1-naphthyl group introduced at the end of the side chain. Therefore, new vitamin K derivatives having more potent anti-SARS-CoV-2 activity were explored by introducing various functional groups at the ω-position of the side chain. MK-2 derivatives with a purine moiety showed the most potent antiviral activity among the derivatives. We also found that their mechanism of action was the inhibition of RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2. The chemical structures of our compounds were completely different from those of nucleic acid derivatives such as remdesivir and molnupiravir, clinically approved RdRp inhibitors for COVID-19 treatment, suggesting that our compounds may be effective against viruses resistant to these nucleic acid derivatives., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)
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- 2023
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34. Hormesis defines the limits of lifespan.
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Calabrese EJ, Osakabe N, Di Paola R, Siracusa R, Fusco R, D'Amico R, Impellizzeri D, Cuzzocrea S, Fritsch T, Abdelhameed AS, Wenzel U, Franceschi C, and Calabrese V
- Subjects
- Humans, Aged, Aging physiology, Adaptation, Physiological, Antioxidants, Hormesis physiology, Longevity
- Abstract
This commentary provides a novel synthesis of how biological systems adapt to a broad spectrum of environmental and age-related stresses that are underlying causes of numerous degenerative diseases and debilitating effects of aging. It proposes that the most fundamental, evolutionary-based integrative strategy to sustain and protect health is based on the concept of hormesis. This concept integrates anti-oxidant, anti-inflammatory and cellular repair responses at all levels of biological organization (i.e., cell, organ and organism) within the framework of biphasic dose responses that describe the quantitative limits of biological plasticity in all cells and organisms from bacteria and plants to humans. A major feature of the hormetic concept is that low levels of biological, chemical, physical and psychological stress upregulate adaptive responses that not only precondition, repair and restore normal functions to damaged tissues/organs but modestly overcompensate, reducing ongoing background damage, thereby enhancing health beyond that in control groups, lacking the low level "beneficial" stress. Higher doses of such stress often become counterproductive and eventually harmful. Hormesis is active throughout the life-cycle and can be diminished by aging processes affecting the onset and severity of debilitating conditions/diseases, especially in elderly subjects. The most significant feature of the hormetic dose response is that the limits of biological plasticity for adaptive processes are less than twice that of control group responses, with most, at maximum, being 30-60 % greater than control group values. Yet, these modest increases can make the difference between health or disease and living or dying. The quantitative features of these adaptive hormetic dose responses are also independent of mechanism. These features of the hormetic dose response determine the capacity to which systems can adapt/be protected, the extent to which biological performance (e.g., memory, resistance to injury/disease, wound healing, hair growth or lifespan) can be enhanced/extended and the extent to which synergistic interactions may occur. Hormesis defines the quantitative rules within which adaptive processes operate and is central to evolution and biology and should become transformational for experimental concepts and study design strategies, public health practices and a vast range of therapeutic strategies and interventions., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2023
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35. Cinnamtannin A2, (-)-epicatechin tetramer, attenuates skeletal muscle wasting in disuse atrophy model mice induced by hindlimb suspension.
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Muta O, Oyama S, Odaka M, Shimizu K, Katsuragawa S, Suzuki K, Fushimi T, Fujii Y, Akagi R, and Osakabe N
- Abstract
The impact of repeated administration of cinntamtannin A2 (A2, 25 μg/kg) on skeletal muscle disuse atrophy model mice induced by hindlimb suspension for 14 days was examined. In soleus, weight loss and a reduction in the average myofibre size with shifting to the smaller side of the peak were observed in the suspension-vehicle group, but A2 reduced these changes. Average myofibre size significantly increased in ground-A2 compared to ground-vehicle. A marked increase in the dephosphorylation of forkhead box O (FoxO) 3a by the suspension was reduced by A2. The phosphorylation of protein kinase B (Akt) and eukaryotic translation initiation factor 4E-binding protein (4EBP)-1 were significantly increased by the treatment of A2. In addition, a single dose of A2 increased dramatically in the 24-h excretion of catecholamines in urine. These results suggest that A2 administration results in sympathetic nerve activation and promotes hypertrophy while inhibiting the progress of disuse muscle atrophy., Competing Interests: No potential conflicts of interest were disclosed., (Copyright © 2023 JCBN.)
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- 2023
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36. Activation of transient receptor potential channels is involved in reactive oxygen species (ROS)-dependent regulation of blood flow by (-)-epicatechin tetramer cinnamtannin A2.
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Fushimi T, Hirahata C, Hiroki K, Fujii Y, Calabrese V, Suhara Y, and Osakabe N
- Subjects
- Rats, Animals, Reactive Oxygen Species metabolism, Hemodynamics, Transient Receptor Potential Channels metabolism, Proanthocyanidins chemistry, Catechin chemistry
- Abstract
Intervention trials confirmed that blood flow-mediated dilatation increases significantly after intake of astringent (-)-epicatechin (EC) oligomers (procyanidins)-rich foods, but the mechanism remains unclear. We have previously found that procyanidins can activate the sympathetic nervous and subsequently increase blood flow. Here, we examined whether procyanidin-derived reactive oxygen species (ROS) activate transient receptor potential (TRP) channels in gastrointestinal sensory nerves and consequently induce sympathoexcitation. We evaluated the redox properties of EC and its tetramer cinntamtannin A2 (A2) at pH 5 or 7, mimicking plant vacuole or oral cavity/small intestine using a luminescent probe. At pH 5, A2 or EC showed O
2 ·- generation at pH 7. We observed blood flow in rat cremaster arterioles using laser Doppler, a single oral dose of 10 µg/kg A2 markedly increased blood flow, while EC showed little activity. This change with A2 was significantly dampened by co-administration of adrenaline blocker, ROS scavenger N-acetyl-L-cysteine (NAC), TRP vanilloid 1, or ankyrin 1 antagonist. We also performed a docking simulation of EC or A2 with the binding site of a typical ligand for each TRP channel and calculated the respective binding affinities. The binding energies were notably higher for A2 than typical ligands, suggesting that A2 is less likely to bind to these sites. ROS produced at neutral pH following the orally administered A2 to the gastrointestinal tract could activate TRP channels, triggering sympathetic hyperactivation and causing hemodynamic changes.2 ·- generation at pH 7. We observed blood flow in rat cremaster arterioles using laser Doppler, a single oral dose of 10 µg/kg A2 markedly increased blood flow, while EC showed little activity. This change with A2 was significantly dampened by co-administration of adrenaline blocker, ROS scavenger N-acetyl-L-cysteine (NAC), TRP vanilloid 1, or ankyrin 1 antagonist. We also performed a docking simulation of EC or A2 with the binding site of a typical ligand for each TRP channel and calculated the respective binding affinities. The binding energies were notably higher for A2 than typical ligands, suggesting that A2 is less likely to bind to these sites. ROS produced at neutral pH following the orally administered A2 to the gastrointestinal tract could activate TRP channels, triggering sympathetic hyperactivation and causing hemodynamic changes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2023
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37. Difference in endocrine and behavior between short-term single- and paired-housing mice in metabolic cage.
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Muta O, Odaka M, Fujii Y, Fushimi T, Sato H, and Osakabe N
- Subjects
- Mice, Animals, Social Isolation, Catecholamines, Housing, Animal, Behavior, Animal, Corticosterone metabolism, Endocrine System
- Abstract
Metabolic cage housing which is exposed to a number of environmental stressors is often used in pharmacokinetic studies. In this study, we compared the difference in stress response between single- and paired-housing in metabolic cages by evaluating the alteration of urinary stress hormones and behavior. Mice were randomly divided into single- or paired-housing groups and placed in a metabolic cage with wire mesh. Their urine was collected every 24 h for consecutive 4 days to determine excreted catecholamine and corticosterone. The change in body weight was significantly decreased at 3 and 4 days in the single-housing group compared with that before the experiment, but not paired-housing group. The level of urinary catecholamines, such as noradrenaline, adrenaline, and their metabolite vanillylmandelic acid, was significantly increased in the single-housing compared with paired housing group and urinary corticosterone increased as well. Next, for the two similarly housed groups, we observed spontaneous behavior on the fourth day and conducted an elevated plus-maze test on the fifth day. Spontaneous behavior was not different between experimental groups. In the elevated plus-maze test, the proportion of time spent in the open arms was significantly prolonged in the paired-housing group compared to that of the single-housing group. Short-term social isolation stress loading in metabolic cages was suggested to exhibit endocrinological and behavioral changes in mice. To reduce such interference due to stress exposure, it was suggested to keep two mice in a metabolic cage., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
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38. Impact of cyanidin 3- O -glucoside on rat micro-and systemic circulation, possibly thorough angiogenesis.
- Author
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Fushimi T, Oyama S, Koizumi R, Fujii Y, and Osakabe N
- Abstract
Cyanidin 3- O -glucoside (C3G), an antioxidant, is one of the most abundant anthocyanin in plant foods. Intervention trials and subsequent meta-analyses have suggested that anthocyanins could reduce the risks of cardiovascular diseases. This study investigated hemodynamic alterations following a single intragastric dose of C3G by measuring blood flow in rat cremaster muscle arteriole for 60 min. Next, in excised aortas, we performed western blotting to measure the phosphorylation of Akt and endothelial nitric oxide synthase (eNOS). A single oral dose of C3G significantly increased blood flow soon after ingestion, and it was maintained throughout the experimental period. In addition, aortic Akt phosphorylation increased. Then, we examined the impact of repeated oral administrations of C3G for 14 days. The mean blood pressure was significantly reduced at 7 and 14 days after treatment, with a slight increase in aortic eNOS expression. Immunohistochemical analyses of the soleus showed that the level of CD31, an angiogenesis-marker protein, was significantly increased with C3G. These results suggested that an oral dose of C3G increased blood flow, which promoted angiogenesis within skeletal muscle, and consequently, blood pressure was reduced., Competing Interests: No potential conflicts of interest were disclosed., (Copyright © 2023 JCBN.)
- Published
- 2023
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39. Hormetic response to B-type procyanidin ingestion involves stress-related neuromodulation via the gut-brain axis: Preclinical and clinical observations.
- Author
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Osakabe N, Fushimi T, and Fujii Y
- Abstract
B-type procyanidins, a series of catechin oligomers, are among the most ingested polyphenols in the human diet. Results of meta-analyses have suggested that intake of B-type procyanidins reduces cardiovascular disease risk. Another recent focus has been on the effects of B-type procyanidins on central nervous system (CNS) function. Although long-term B-type procyanidin ingestion is linked to health benefits, a single oral intake has been reported to cause physiological alterations in circulation, metabolism, and the CNS. Comprehensive analyses of previous reports indicate an optimal mid-range dose for the hemodynamic effects of B-type procyanidins, with null responses at lower or higher doses, suggesting hormesis. Indeed, polyphenols, including B-type procyanidins, elicit hormetic responses in vitro , but animal and clinical studies are limited. Hormesis of hemodynamic and metabolic responses to B-type procyanidins was recently confirmed in animal studies, however, and our work has linked these effects to the CNS. Here, we evaluate the hormetic response elicited by B-type procyanidins, recontextualizing the results of intervention trials. In addition, we discuss the possibility that this hormetic response to B-type procyanidins arises via CNS neurotransmitter receptors. We have verified the direction of future research for B-type procyanidins in this review., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Osakabe, Fushimi and Fujii.)
- Published
- 2022
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40. Can a Short-term Daily Oral Administration of Propolis Improve Muscle Fatigue and Recovery?
- Author
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Tsuchiya Y, Hirata N, Asama T, Osakabe N, Hirata K, and Akagi R
- Subjects
- Administration, Oral, Double-Blind Method, Electromyography, Humans, Isometric Contraction physiology, Male, Muscle Contraction physiology, Muscle, Skeletal physiology, Torque, Muscle Fatigue physiology, Propolis
- Abstract
This study investigated the effect of 1-week oral administration of propolis on muscle fatigue and recovery after performing a fatigue task (total 100 maximal voluntary concentric knee extension repetitions). In this placebo-controlled, double-blind study, 18 young men consumed a formulation with high Brazilian green propolis dose (H-BGP), a formulation with low Brazilian green propolis dose, or a placebo, for 1 week before performing the fatigue task (an interval between each intervention: 1-2 weeks). Maximal voluntary contraction torque, central fatigue (voluntary activation and root mean square values of the surface electromyography amplitude), and peripheral fatigue (potentiated triplet torque) were assessed before, immediately after, and 2 minutes after the fatigue task. Maximal voluntary contraction torque decreased immediately after the fatigue task in all conditions (P<0.001); however, it recovered from immediately after to 2 minutes after the fatigue task only in the H-BGP condition (P<0.001). Furthermore, there was a significant decrease in voluntary activation (P<0.001) and root mean square values of the surface electromyography amplitude (P≤0.035) only in the placebo condition. No significant difference was observed in the time-course change in potentiated triplet torque between the conditions. These results suggest that oral administration of propolis promotes muscle fatigue recovery by reducing central fatigue., Competing Interests: Ryota Akagi received a research fund for this study from Yamada Bee Company, Inc. Takashi Asama is an employee of Yamada Bee Company, Inc. The other authors declare no conflicts of interest associated with this study., (Thieme. All rights reserved.)
- Published
- 2022
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41. Impact of short-term oral dose of cinnamtannin A2, an (-)-epicatechin tetramer, on spatial memory and adult hippocampal neurogenesis in mouse.
- Author
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Fujii Y, Sakata J, Sato F, Onishi K, Yamato Y, Sakata K, Taira S, Sato H, and Osakabe N
- Subjects
- Administration, Oral, Animals, Anthocyanins administration & dosage, Anthocyanins chemistry, Bromodeoxyuridine metabolism, Catechin administration & dosage, Catechin chemistry, Dentate Gyrus cytology, Dentate Gyrus metabolism, Exploratory Behavior drug effects, Exploratory Behavior physiology, Hippocampus cytology, Hippocampus physiology, Mice, Inbred C57BL, Molecular Structure, Motor Activity drug effects, Motor Activity physiology, Spatial Memory physiology, Time Factors, Mice, Anthocyanins pharmacology, Catechin pharmacology, Hippocampus drug effects, Neurogenesis drug effects, Spatial Memory drug effects
- Abstract
Recent epidemiological and intervention studies have suggested that polyphenol-rich plant food consumption reduced the risk of cognitive decline. However, the findings were tentative and by no means definitive. In the present study, we examined the impact of short-term oral administration of cinnamtannin A2 (A2), an (-)-epicatechin tetramer, on adult hippocampal neurogenesis and cognitive function in mice. Mice received supplementation with vehicle (20% glycerol) or 100 μg/kg A2 for 10 days. Then, we conducted the open field test, the object location test, and the novel object test. In the open field test, the A2-treated group tended to spend more time in the center of the arena, compared to the vehicle-treated group. The A2-treated group spent significantly more time exploring objects placed in different locations, compared to the vehicle-treated group. There were no significant differences between groups in the object preference index or in the novel object test. In addition, A2 administration significantly increased the number of hippocampal bromodeoxyuridine-labeled cells in the dentate gyrus, but not in the CA1 or CA3 regions. These results suggested that short-term administration of A2 may impact spatial memory by enhancing neurogenesis in the dentate gyrus of adult mice., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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42. Repeated Oral Administration of Flavan-3-ols Induces Browning in Mice Adipose Tissues through Sympathetic Nerve Activation.
- Author
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Ishii Y, Muta O, Teshima T, Hirasima N, Odaka M, Fushimi T, Fujii Y, and Osakabe N
- Subjects
- Administration, Oral, Animals, Catecholamines urine, Membrane Proteins metabolism, Mice, Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha metabolism, Positive Regulatory Domain I-Binding Factor 1 metabolism, Thermogenesis drug effects, Tumor Necrosis Factor Receptor Superfamily, Member 9 metabolism, Uncoupling Protein 1 metabolism, Adipose Tissue metabolism, Flavonoids administration & dosage, Sympathetic Nervous System drug effects
- Abstract
We previously found increases in uncoupling protein (Ucp)-1 transcription in brown adipose tissue (BAT) of mice following a single oral dose of flavan 3-ol (FL)s, a fraction of catechins and procyanidins. It was confirmed that these changes were totally reduced by co-treatment of adrenaline blockers. According to these previous results, FLs possibly activate sympathetic nervous system (SNS). In this study, we confirmed the marked increase in urinary catecholamine (CA) s projecting SNS activity following a single dose of 50 mg/kg FLs. In addition, we examined the impact of the repeated administration of 50 mg/kg FLs for 14 days on adipose tissues in mice. In BAT, FLs tended to increase the level of Ucp-1 along with significant increase of thermogenic transcriptome factors expressions, such as peroxisome proliferator-activated receptor γ coactivator (PGC)-1α and PR domain-containing (PRDM)1 . Expression of browning markers, CD137 and transmembrane protein (TMEM) 26 , in addition to PGC-1α were increased in epididymal adipose (eWAT) by FLs. A multilocular morphology with cell size reduction was shown in the inguinal adipose (iWAT), together with increasing the level of Ucp-1 by FLs. These results exert that FLs induce browning in adipose, and this change is possibly produced by the activation of the SNS.
- Published
- 2021
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43. Method for detecting hemodynamic alterations following a single gavage in rats.
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Fushimi T, Fujii Y, Koshino H, Inagawa K, Saito A, Koizumi R, Shibata M, and Osakabe N
- Subjects
- Animals, Male, Rats, Wistar, Hemodynamics, Intubation, Gastrointestinal methods, Laboratory Animal Science methods, Rats blood
- Abstract
It is known that administering a gavage to rodents evokes a cardiac reflex, due to gastrointestinal stimulation. Consequently, it is difficult to evaluate changes in hemodynamics after a single oral dose of a pungent or astringent, which alters the circulation by increasing sympathetic activity. In the present study, we developed a method for administering a gavage without significantly affecting hemodynamics measurements. We marked a gastric tube at 10 cm from the tip, to mark the distance from the oral cavity to the stomach body of Wistar male rats. Rats were intubated under urethane anesthesia.After 10-15 min of stabilization, we measured the mean blood pressure (MBP), heart rate (HR), and blood flow (BF) in the cremaster arteriole under two different conditions; condition 1: a pointed gastric tube, room temperature distilled water, and injected at normal speed (approximately 3 ml/min); condition 2: a rounded gastric tube, 37°C distilled water, and injection at 1.0 ml/min. Under condition 1, we observed striking hemodynamic alterations, due to the somatic afferent reflex. In contrast, under condition 2, these hemodynamic changes were nearly eliminated. In addition, we could clearly detect hemodynamic changes in rats after a single gavage treatment of pungent (capsaicin) or astringent (cinnamtannin A2). We observed transient increases in the HR and MBP soon after treatment with capsaicin. Moreover, cremasteric BF was elevated with cinnamtannin A2. These results confirmed the utility of the gavage method developed in this study.
- Published
- 2021
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44. Relationship between hemodynamic alteration and sympathetic nerve activation following a single oral dose of cinnamtannin A2.
- Author
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Koizumi R, Fushimi T, Sato Y, Fujii Y, Sato H, and Osakabe N
- Subjects
- Administration, Oral, Animals, Anthocyanins pharmacology, Humans, Male, Rats, Rats, Wistar, Anthocyanins therapeutic use, Hemodynamics physiology, Sympathetic Nervous System drug effects
- Abstract
We previously found that a single dose of B-type procyanidin mixture increase in skeletal muscle blood flow (BF). We compared BF changes following administration of (-)-epicatechin (EC, monomer) and the B-type procyanidins procyanidin B2 (B2, dimer), procyanidin C1 (C1, trimer), and cinnamtannin A2 (A2, tetramer). Each chemical was administered orally to rats, followed by BF measurement in cremaster arteriole for 60 min. About 10 and 100 µg/kg of B2 and C1 elicited BF increase, the effect was potent at 100 µg/kg. BF also increased significantly after administration of 10 µg/kg A2, but not with the administration at 100 µg/kg. EC yielded no BF changes. Co-treatment with the nonselective adrenaline blocker carvedilol attenuated the BF increase seen with 10 µg/kg A2 treatment. This outcome suggested the involvement of sympathetic nerve activation in the BF increase by this dose of A2. Co-treatment of 100 µg/kg A2 with the α2 blocker yohimbine exhibited an increase of BF significantly. The α2 adrenaline receptor in the vasomotor centre is an inhibitory receptor and it regulates hemodynamics. This result suggested that high doses of A2 did not alter BF because of activating the α2 adrenergic receptor. Phosphorylation of aortic endothelial nitric oxide synthase (eNOS) increased with 10 µg/kg A2 alone or co-treatment with 100 µg/kg A2 and yohimbine, but not with co-treatment of 10 µg/kg A2 and carvedilol or 100 µg/kg A2 alone. These results imply that A2 does not directly activate eNOS, but that shear stress from the increased BF might be associated with eNOS phosphorylation.
- Published
- 2021
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45. Theaflavins decrease skeletal muscle wasting in disuse atrophy induced by hindlimb suspension in mice.
- Author
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Suzuki K, Hirashima N, Fujii Y, Fushimi T, Yamamoto A, Ueno T, Akagi R, and Osakabe N
- Abstract
We previously found that a single dose of theaflavins induced skeletal muscle metabolic changes. In this study, we examined the effect of theaflavins on disuse muscle atrophy model mice by hindlimb suspension. Mice were assigned to 4 groups; ground-vehicle, ground-theaflavins, suspension-vehicle, and suspension-theaflavins, dosed with theaflavins (250 mg/kg/day) for 2 weeks. The peak of myotube size of cross sectional area was significantly moved to the smaller side in the suspension-vehicle group compared with the ground-vehicle group, and these shifts were significantly reduced by the treatment with theaflavins in both soleus and extensor digitorum longus. The level of phosphorylated eukaryotic translation initiation factor 4E-binding protein (4EBP)-1, located downstream of the Akt/mTOR pathway, was significantly different between suspension-vehicle and suspension-theaflavins in soleus. The ratio of forkhead box O (FoxO) 3a to phosphorylated FoxO3a significantly increased in soleus or tended to rise in extensor digitorum longus of suspension-vehicle group compared with ground-vehicle. In contrast, these changes were not observed in suspension-theaflavins group. These results suggested that theaflavins inhibited the progress of disuse muscle atrophy through modulation of protein metabolism., Competing Interests: This study was funded by Yaizu Suisankagaku Ind. Co. Ltd. AY and TU are employees of Yaizu Suisankagaku Ind. Co. Ltd. and provide research source. KS, NH, YF, TF, RA, and NO declare no competing interests., (Copyright © 2021 JCBNCopyright © 2021 JCBN.)
- Published
- 2021
- Full Text
- View/download PDF
46. Electrochemical Analysis of Coffee Extractions at Different Roasting Levels Using a Carbon Nanotube Electrode.
- Author
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Wada R, Takahashi S, Muguruma H, and Osakabe N
- Subjects
- Electrodes, Coffee chemistry, Electrochemical Techniques, Nanotubes, Carbon chemistry, Plant Extracts analysis
- Abstract
This study reports on the electrochemical analysis of coffee extractions at different roasting levels by using a carbon nanotube (CNT) electrode. The roasting levels, ranging from 1 (low) to 6 (high), were determined according to the roasting time after fixing the roasting temperature. Level 1 roasting resulted in light roasted beans and level 6 in dark roasted ones. Based on the roasting level, the concentration of chlorogenic acids, including 3-caffeoylquinic (3CQ), 4-caffeoylquinic (4CQ), and 5-caffeoylquinic (5CQ) acid, can be determined. Cyclic voltammetry (CV) experiments revealed that the reduction current at +0.27 V was proportional to the concentration of chlorogenic acids. High-performance liquid chromatography (HPLC) revealed an inverse correlation between the roasting level and chlorogenic acid amount. The total amounts of chlorogenic acids in coffee extractions determined by HPLC were in agreement with those obtained by CV using the CNT electrode at roasting levels 1 - 5. At level 6, the amount of chlorogenic acids determined by the current peak was larger than that detected by HPLC. As a result, the chlorogenic acid amount was overestimated in the CV experiment at +0.27 V, indicating that electrochemically active materials were generated at level 6. The CV profile showed that the reduction peak at +0.10 V increased with an increase in roasting level. Thus, the peak intensity at +0.10 V can be used to evaluate the roasting level even if the concentration or dilution conditions are provided.
- Published
- 2021
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47. Effects of Cocoa Polyphenols and Dark Chocolate on Obese Adults: A Scoping Review.
- Author
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Halib H, Ismail A, Mohd Yusof BN, Osakabe N, and Mat Daud ZA
- Subjects
- Biomarkers blood, Blood Glucose metabolism, Blood Pressure, Body Mass Index, Body Weight, Cardiovascular Diseases prevention & control, Flavonoids analysis, Flavonoids pharmacology, Humans, Observational Studies as Topic, Randomized Controlled Trials as Topic, Waist Circumference, Cacao chemistry, Chocolate analysis, Obesity prevention & control, Polyphenols analysis, Polyphenols pharmacology
- Abstract
Obesity remains a major public health problem due to its increasing prevalence. Natural products have become common as adjunct therapeutic agents for treating obesity and preventing metabolic diseases. Cocoa and its products are commonly consumed worldwide. Dark chocolate, a rich source of polyphenols, has received attention lately for its beneficial role in the management of obesity; however, conflicting results are still being reported. This scoping review aims to provide a comprehensive understanding of the existing literature on the relationship and effects of cocoa and dark chocolate intake among obese adults. We searched multiple databases for research investigating the consumption of cocoa and/or dark chocolate in managing obesity among adults. This review includes epidemiological and human studies that were published in English over the last 10 years. Our review of the current literature indicates that epidemiological and human trials with obese adults have shown inconsistent results, which may be due to the different populations of subjects, and different types of cocoa products and doses used for intervention. Studies among obese adults are mainly focusing on obese individuals with comorbidities, as such more studies are needed to elucidate the role of cocoa polyphenols in weight control and preventing the risk of chronic diseases among obese individuals without comorbidities as well as healthy individuals. Careful adjustment of confounding factors would be required. The effects of cocoa and dark chocolate intake on obese adults were discussed, and further research is warranted to identify the gaps.
- Published
- 2020
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48. Electrochemical Detection of Curcumin in Food with a Carbon Nanotube-Carboxymethylcellulose Electrode.
- Author
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Wada R, Takahashi S, Muguruma H, and Osakabe N
- Subjects
- Electrodes, Oxidation-Reduction, Carboxymethylcellulose Sodium chemistry, Curcumin analysis, Electrochemistry instrumentation, Food Analysis instrumentation, Nanotubes, Carbon chemistry
- Abstract
Herein, an electrochemical method is presented for the detection of curcumin in food using a carbon nanotube (CNT)-carboxymethylcellulose (CMC) electrode. The CNT-CMC electrode exhibited ideal characteristics for curcumin detection, namely, a high response current and adequate peak separation toward curcumin oxidation. Cyclic voltammetry revealed two oxidation peaks. In the first scan, only the irreversible peak (Peak I) was observed at a higher potential. In the second scan, the reversible redox peak pairs (Peaks II and II') appeared at lower potentials, and the potential of Peak I was decreased. Peak I corresponded to oxidation of the hydroxyl groups of the benzene ring to the catechol group via a phenoxy radical, while Peaks II and II' indicated the redox loop system of the generated catechol group. The current at Peak II was used to quantify the concentration of curcumin in the linear range of 1 - 48 μM and detection limit of 0.084 μM. The concentrations of curcumin determined by the CNT-CMC electrode in real food samples were consistent with those determined by high-performance liquid chromatography.
- Published
- 2020
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49. Study on structure-activity relationship of vitamin K derivatives: Conversion of the naphthoquinone part into another aromatic ring and evaluation of their neuronal differentiation-inducing activity.
- Author
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Yoshimura H, Hirota Y, Soda S, Okazeri M, Takagi Y, Takeuchi A, Tode C, Kamao M, Osakabe N, and Suhara Y
- Subjects
- Animals, Benzene Derivatives chemistry, Benzoquinones chemistry, Cell Differentiation drug effects, Dose-Response Relationship, Drug, Mice, Molecular Structure, Naphthoquinones chemistry, Quantitative Structure-Activity Relationship, Vitamin K chemistry, Benzene Derivatives pharmacology, Benzoquinones pharmacology, Naphthoquinones pharmacology, Neurons drug effects, Vitamin K pharmacology
- Abstract
We synthesized novel vitamin K derivatives by converting the naphthoquinone group to benzene derivatives and benzoquinone. We evaluated their neuronal differentiation activities to investigate the effect of the quinone moiety on this process. We observed that the 1,4-quinone as well as the side chain part play important roles in neuronal differentiation. We also performed QSAR analysis to predict the compounds which would have higher differentiation activity., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2020
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50. Dual real-time in vivo monitoring system of the brain-gut axis.
- Author
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Nishimura Y, Fukuda Y, Okonogi T, Yoshikawa S, Karasuyama H, Osakabe N, Ikegaya Y, Sasaki T, and Adachi T
- Subjects
- Animals, Brain drug effects, Calcium Signaling drug effects, Capsaicin pharmacology, Cell Line, Cells, Cultured, Electrophysiological Phenomena, Enteric Nervous System drug effects, Gastrointestinal Tract drug effects, Gastrointestinal Tract innervation, Male, Mice, Mice, Inbred C57BL, Monitoring, Physiologic, Sensory System Agents pharmacology, Vagus Nerve drug effects, Brain physiology, Enteric Nervous System physiology, Gastrointestinal Tract physiology, Vagus Nerve physiology
- Abstract
The brain-gut axis which is an interaction between recognition and emotion and the gut sensory system for food and microbiota is important for health. However, there is no real-time monitoring system of the brain and the gut simultaneously so far. We attempted to establish a dual real-time monitoring system for the brain-gut axis by a combination of intravital Ca
2+ imaging of the gut and electroencephalogram. Using a conditional Yellow Cameleon 3.60 expression mouse line, we performed intravital imaging of the gut, electrophysiological recordings of the vagus nerve, and electroencephalogram recordings of the various cortical regions simultaneously upon capsaicin stimuli as a positive control. Upon capsaicin administration into the small intestinal lumen, a simultaneous response of Ca2+ signal in the enteric nervous system and cortical local field potentials (LFPs) was successfully observed. Both of them responded immediately upon capsaicin stimuli. Capsaicin triggered a significant increase in the frequency of vagus nerve spikes and a significant decrease in the slow-wave power of cortical LFPs. Furthermore, capsaicin induced delayed and sustained Ca2+ signal in intestinal epithelial cells and then suppressed intestinal motility. The dual real-time monitoring system of the brain and the gut enables to dissect the interaction between the brain and the gut over time with precision., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
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