770 results on '"N Kikuchi"'
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2. Updated spectral radiance calibration on TIR bands for TANSO-FTS-2 onboard GOSAT-2
- Author
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H. Suto, F. Kataoka, R. O. Knuteson, K. Shiomi, N. Kikuchi, and A. Kuze
- Subjects
Environmental engineering ,TA170-171 ,Earthwork. Foundations ,TA715-787 - Abstract
The Thermal and Near-Infrared Sensor for Carbon Observation Fourier-Transform Spectrometer-2 (TANSO-FTS-2) onboard the Japanese Greenhouse Gases Observing SATellite-2 (GOSAT-2) observes a wide spectral region of the atmosphere, from the ShortWave-InfraRed (SWIR) to the longwave Thermal InfraRed radiation (TIR) with 0.2 cm−1 spectral sampling, and the corresponding spectral resolution (full width at half maximum, FWHM) of TIR region is less than 0.27 cm−1. TANSO-FTS-2 has operated nominally since February 2019, and the atmospheric radiance spectra it has acquired have been released to the public. This paper describes an updated model for spectral radiance calibration and its validation. The model applies to the version v210210 TIR products of TANSO-FTS-2 and integrates polarization sensitivity correction for the internal optics and the pointing mirror thermal emission. These correction parameters are characterized by an optimization that depends on the difference between the spectral radiance of TANSO-FTS-2 and coincident nadir observation data from the Infrared Atmospheric Sounding Interferometer (IASI) on METOP-B. To validate the updated spectral radiance product against other satellite products, temporally and spatially coincident observation points were considered for the simultaneous nadir overpass (SNO) from February 2019 to March 2021 from the Atmospheric Infrared Sounder (AIRS) on Aqua, IASI on METOP-B, and TANSO-FTS on GOSAT. The agreement of brightness temperatures between TANSO-FTS-2 and AIRS and IASI was better than 0.3 K (1σ) from 180 to 330 K for the 680 cm−1 CO2 spectral range. The brightness temperatures between TANSO-FTS-2 and TANSO-FTS of version v230231, which implemented a new polarization reflectivity of the pointing mirror and was released in June 2021, generally agree from 220 to 320 K. However, there is a discrepancy at lower brightness temperatures, pronounced for CO2 spectral ranges at high latitudes. To characterize the spectral radiance bias for along-track and cross-track angles, a 2-orthogonal simultaneous off-nadir overpass (2O-SONO) is now done for TANSO-FTS-2 and IASI, TANSO-FTS-2 and AIRS, and TANSO-FTS-2 and TANSO-FTS. The 2O-SONO comparison results indicate that the TIR product for TANSO-FTS-2 has a bias that exceeds 0.5 K in the CO2 spectral range for scenes with forward and backward viewing angles greater than 20∘. These multi-satellite sensor and multi-angle comparison results suggest that the calibration of spectral radiance for TANSO-FTS-2 TIR, version v210210, is superior to that of the previous version in its consistency of multi-satellite sensor data. In addition, the paper identifies the remaining challenging issues in current TIR products.
- Published
- 2022
- Full Text
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3. Thermal and near-infrared sensor for carbon observation Fourier transform spectrometer-2 (TANSO-FTS-2) on the Greenhouse gases Observing SATellite-2 (GOSAT-2) during its first year in orbit
- Author
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H. Suto, F. Kataoka, N. Kikuchi, R. O. Knuteson, A. Butz, M. Haun, H. Buijs, K. Shiomi, H. Imai, and A. Kuze
- Subjects
Environmental engineering ,TA170-171 ,Earthwork. Foundations ,TA715-787 - Abstract
The Japanese Greenhouse gases Observing SATellite-2 (GOSAT-2), in orbit since 29 October 2018, follows up the GOSAT mission, itself in orbit since 23 January 2009. GOSAT-2 monitors carbon dioxide and methane in order to increase our understanding of the global carbon cycle. It simultaneously measures carbon monoxide emitted from fossil fuel combustion and biomass burning and permits identification of the amount of combustion-related carbon. To do this, the satellite utilizes the Thermal and Near Infrared Sensor for Carbon Observation Fourier-Transform Spectrometer-2 (TANSO-FTS-2). This spectrometer detects gas absorption spectra of solar radiation reflected from the Earth's surface in the shortwave-infrared (SWIR) region as well as the emitted thermal infrared radiation (TIR) from the ground and the atmosphere. TANSO-FTS-2 can measure the oxygen A band (0.76 µm), weak and strong CO2 bands (1.6 and 2.0 µm), weak and strong CH4 bands (1.6 and 2.3 µm), a weak CO band (2.3 µm), a mid-wave TIR band (5.5–8.4 µm), and a long-wave TIR band (8.4–14.3 µm) with 0.2 cm−1 spectral sampling intervals. TANSO-FTS-2 is equipped with a solar diffuser target, a monochromatic light source, and a blackbody for spectral radiance calibration. These calibration sources permit characterization of time-dependent instrument changes in orbit. The onboard-recalibrated instrumental parameters are considered in operational level-1 processing and released as TANSO-FTS-2 level-1 version 102102 products, which were officially released on 25 May 2020. This paper provides an overview of the TANSO-FTS-2 instrument, the level-1 processing, and the first-year in-orbit performance. To validate the spectral radiance calibration during the first year of operation, the spectral radiance of the version 102102 product is compared at temporally coincident and spatially collocated points from February 2019 to March 2020 with TANSO-FTS on GOSAT for SWIR and with AIRS on Aqua and IASI on METOP-B for TIR. The spectral radiances measured by TANSO-FTS and TANSO-FTS-2 agree within 2 % of the averaged bias and 0.5 % standard deviation for SWIR bands. The agreement of brightness temperature between TANSO-FTS-2 and AIRS–IASI is better than 1 K in the range from 220 to 320 K. GOSAT-2 not only provides seamless global CO2 and CH4 observation but also observes local emissions and uptake with an additional CO channel, fully customized sampling patterns, higher signal-to-noise ratios, and wider pointing angles than GOSAT.
- Published
- 2021
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4. Improvement of the retrieval algorithm for GOSAT SWIR XCO2 and XCH4 and their validation using TCCON data
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Y. Yoshida, N. Kikuchi, I. Morino, O. Uchino, S. Oshchepkov, A. Bril, T. Saeki, N. Schutgens, G. C. Toon, D. Wunch, C. M. Roehl, P. O. Wennberg, D. W. T. Griffith, N. M. Deutscher, T. Warneke, J. Notholt, J. Robinson, V. Sherlock, B. Connor, M. Rettinger, R. Sussmann, P. Ahonen, P. Heikkinen, E. Kyrö, J. Mendonca, K. Strong, F. Hase, S. Dohe, and T. Yokota
- Subjects
Environmental engineering ,TA170-171 ,Earthwork. Foundations ,TA715-787 - Abstract
The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO2 and XCH4) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the National Institute for Environmental Studies (NIES). XCO2 and XCH4 retrieved using the version 01.xx retrieval algorithm showed large negative biases and standard deviations (−8.85 and 4.75 ppm for XCO2 and −20.4 and 18.9 ppb for XCH4, respectively) compared with data of the Total Carbon Column Observing Network (TCCON). Multiple reasons for these error characteristics (e.g., solar irradiance database, handling of aerosol scattering) are identified and corrected in a revised version of the retrieval algorithm (version 02.xx). The improved retrieval algorithm shows much smaller biases and standard deviations (−1.48 and 2.09 ppm for XCO2 and −5.9 and 12.6 ppb for XCH4, respectively) than the version 01.xx. Also, the number of post-screened measurements is increased, especially at northern mid- and high-latitudinal areas.
- Published
- 2013
- Full Text
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5. A joint effort to deliver satellite retrieved atmospheric CO2 concentrations for surface flux inversions: the ensemble median algorithm EMMA
- Author
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R. Parker, S. Oshchepkov, N. Kikuchi, J. Heymann, O. Hasekamp, S. Guerlet, C. W. O'Dell, J. P. Burrows, A. Butz, M. Buchwitz, A. Bril, H. Bovensmann, H. Bösch, M. Reuter, S. Pfeifer, O. Schneising, T. Yokota, and Y. Yoshida
- Subjects
Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
We analyze an ensemble of seven XCO2 retrieval algorithms for SCIAMACHY (scanning imaging absorption spectrometer of atmospheric chartography) and GOSAT (greenhouse gases observing satellite). The ensemble spread can be interpreted as regional uncertainty and can help to identify locations for new TCCON (total carbon column observing network) validation sites. Additionally, we introduce the ensemble median algorithm EMMA combining individual soundings of the seven algorithms into one new data set. The ensemble takes advantage of the algorithms' independent developments. We find ensemble spreads being often < 1 ppm but rising up to 2 ppm especially in the tropics and East Asia. On the basis of gridded monthly averages, we compare EMMA and all individual algorithms with TCCON and CarbonTracker model results (potential outliers, north/south gradient, seasonal (peak-to-peak) amplitude, standard deviation of the difference). Our findings show that EMMA is a promising candidate for inverse modeling studies. Compared to CarbonTracker, the satellite retrievals find consistently larger north/south gradients (by 0.3–0.9 ppm) and seasonal amplitudes (by 1.5–2.0 ppm).
- Published
- 2013
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6. On-orbit radiometric calibration of SWIR bands of TANSO-FTS onboard GOSAT
- Author
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Y. Yoshida, N. Kikuchi, and T. Yokota
- Subjects
Environmental engineering ,TA170-171 ,Earthwork. Foundations ,TA715-787 - Abstract
The Greenhouse gases Observing SATellite (GOSAT) was launched on 23 January 2009 to monitor global distributions of carbon dioxide and methane. The Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard GOSAT measures the short-wavelength infrared (SWIR) spectra. Radiometric accuracy directly influences the accuracy of the retrieved greenhouse gas concentrations. From a 2.5-yr retrieval analysis of GOSAT data, we found that the minimum of the mean-squared value of the residuals (the difference between observed and fitted spectra) and the radiance adjustment factor (one of the ancillary parameters to be retrieved with the gas concentrations for adjusting the radiance level between the bands) changed with time, possibly due to inaccurate degradation correction. In this study, the radiometric degradation of TANSO-FTS was evaluated from the on-orbit solar calibration data and modeled as a function of time and wavenumber for each spectral band. The radiometric degradation of TANSO-FTS Band 1 (centered at 0.76 μm) after the launch was found to be about 4 to 6%, varying with wavenumber, whereas the other two bands (Band 2: 1.6 μm and Band 3: 2.0 μm) showed about 1% degradation and small wavenumber dependency. When we applied the new degradation model in the retrieval analysis, the above-mentioned issues disappeared.
- Published
- 2012
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7. Influence of aerosols and thin cirrus clouds on the GOSAT-observed CO2: a case study over Tsukuba
- Author
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A. Bril, S. Oshchepkov, N. Kikuchi, A. Uchiyama, A. Yamazaki, T. Shibata, A. Shimizu, T. Nagai, Y. Yoshida, I. Morino, T. Sakai, O. Uchino, and T. Yokota
- Subjects
Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Lidar observations of vertical profiles of aerosols and thin cirrus clouds were made at Tsukuba (36.05° N, 140.12° E), Japan, to investigate the influence of aerosols and thin cirrus clouds on the column-averaged dry-air mole fraction of carbon dioxide (XCO2) retrieved from observation data of the Thermal And Near-infrared Sensor for carbon Observation Fourier Transform Spectrometer, measured in the Short-Wavelength InfraRed band (TANSO-FTS SWIR), onboard the Greenhouse gases Observing SATellite (GOSAT). The lidar system measured the backscattering ratio, depolarization ratio, and/or the wavelength exponent of atmospheric particles. The lidar observations and ground-based high-resolution FTS measurements at the Tsukuba Total Carbon Column Observing Network (Tsukuba TCCON) site were recorded simultaneously during passages of GOSAT over Tsukuba. GOSAT SWIR XCO2 data (Version 01.xx) released in August 2010 were compared with the lidar and Tsukuba TCCON data. High-altitude aerosols and thin cirrus clouds had a large impact on the GOSAT SWIR XCO2 results. By taking into account the observed aerosol/cirrus vertical profiles and using a more adequate solar irradiance database in the GOSAT SWIR retrieval, the difference between the GOSAT SWIR XCO2 data and the Tsukuba TCCON data was reduced. The 3-band retrieval approach where the aerosol and cirrus profiles were retrieved gave us the best results and the retrieved XCO2 data followed the seasonal cycle of ~8 ppm observed at Tsukuba TCCON site.
- Published
- 2012
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8. Retrieval algorithm for CO2 and CH4 column abundances from short-wavelength infrared spectral observations by the Greenhouse gases observing satellite
- Author
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I. Morino, H. Tran, K. Nobuta, N. Kikuchi, N. Eguchi, Y. Ota, Y. Yoshida, and T. Yokota
- Subjects
Environmental engineering ,TA170-171 ,Earthwork. Foundations ,TA715-787 - Abstract
The Greenhouse gases Observing SATellite (GOSAT) was launched on 23 January 2009 to monitor the global distributions of carbon dioxide and methane from space. It has operated continuously since then. Here, we describe a retrieval algorithm for column abundances of these gases from the short-wavelength infrared spectra obtained by the Thermal And Near infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS). The algorithm consists of three steps. First, cloud-free observational scenes are selected by several cloud-detection methods. Then, column abundances of carbon dioxide and methane are retrieved based on the optimal estimation method. Finally, the retrieval quality is examined to exclude low-quality and/or aerosol-contaminated results. Most of the retrieval random errors come from instrumental noise. The interferences due to auxiliary parameters retrieved simultaneously with gas abundances are small. The evaluated precisions of the retrieved column abundances for single observations are less than 1% in most cases. The interhemispherical differences and temporal variation patterns of the retrieved column abundances show features similar to those of an atmospheric transport model.
- Published
- 2011
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9. Comparison between Satellite Water Vapour Observations and Atmospheric Models’ Predictions of the Upper Tropospheric Thermal Radiation
- Author
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J. R. Dim, T. Y. Nakajima, T. Takamura, and N. Kikuchi
- Subjects
Meteorology. Climatology ,QC851-999 - Abstract
Atmospheric profiles (temperature, pressure, and humidity) are commonly used parameters for aerosols and cloud properties retrievals. In preparation of the launch of the Global Change Observation Mission-Climate/Second-Generation GLobal Imager (GCOM-C/SGLI) satellite, an evaluation study on the sensitivity of atmospheric models to variations of atmospheric conditions is conducted. In this evaluation, clear sky and above low clouds water vapour radiances of the upper troposphere obtained from satellite observations and those simulated by atmospheric models are compared. The models studied are the Nonhydrostatic ICosahedral Atmospheric Model (NICAM) and the National Center for Environmental Protection/Department Of Energy (NCEP/DOE). The satellite observations are from the Terra/Moderate Resolution Imaging Spectroradiometer (Terra/MODIS) satellite. The simulations performed are obtained through a forward radiative transfer calculation procedure. The resulting radiances are transformed into the upper tropospheric brightness temperature (UTBT) and relative humidity (UTRH). The discrepancies between the simulated data and the observations are analyzed. These analyses show that both the NICAM and the NCEP/DOE simulated UTBT and UTRH have comparable distribution patterns. However the simulations’ differences with the observations are generally lower with the NCEP/DOE than with the NICAM. The NCEP/DOE model outputs very often overestimate the UTBT and therefore present a drier upper troposphere. The impact of the lower troposphere instability (dry convection) on the upper tropospheric moisture and the consequences on the models’ results are evaluated through a thunderstorm and moisture predictor (the K-stability index). The results obtained show a positive relation between the instability and the root mean square error (RMSE: observation versus models). The study of the impact of convective clouds shows that the area covered by these clouds increases with the humidity of the upper troposphere in clear sky and above low clouds, and at the same time, the error between the observations and the models also increases. The impact of the above low clouds heat distribution on the models is studied through the relation between the low clouds cover and their effective emissivity. The models’ error appears to be high at midrange effective emissivity clouds.
- Published
- 2011
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10. Chaos control and noise suppression in external-cavity semiconductor lasers
- Author
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N. Kikuchi, Yun Liu, and Junji Ohtsubo
- Subjects
Physics ,Laser diode ,business.industry ,Relative intensity noise ,Quantum noise ,Condensed Matter Physics ,Laser ,Optical chaos ,Atomic and Molecular Physics, and Optics ,law.invention ,Semiconductor laser theory ,Optics ,law ,Modulation (music) ,Electrical and Electronic Engineering ,business ,Frequency modulation - Abstract
Feedback-induced chaos and intensity noise enhancement in a laser diode with external optical feedback are studied by computer simulations. The enhancement of relative intensity noise (RIN) that is often observed in experiments is considered as a result of the feedback-induced deterministic chaos and the intensity noise suppression is treated from the viewpoint of chaos control. Especially, the conventional noise suppressing technique known as a high-frequency injection modulation is turned into a problem of stabilizing chaos through parameter modulations. We developed an analytical method which allows to optimize the modulation frequency from the linear stability analysis of the dynamical model that describes the laser diode with external feedback. The robustness of the modulation with respect to the modulation frequency and depth is verified and the results suggest the feasibility of applying our method to actual noise suppression. The RIN in the low-frequency region (up to 100 MHz) is shown to be reduced to the solitary laser level when the feedback-induced chaos is effectively controlled with the optimized modulation frequency.
- Published
- 1997
11. AHE measurements of very thin films and nanosized dots
- Author
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R. Murillo, J.C. Lodder, and N. Kikuchi
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Materials science ,SMI-EXP: EXPERIMENTAL TECHNIQUES ,Condensed matter physics ,Ion beam ,Magnetization reversal ,Condensed Matter Physics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,TST-LIL: Laser Interference Lithography ,SMI-TST: From 2006 in EWI-TST ,Electronic, Optical and Magnetic Materials ,Hysteresis ,TSTNE-Magnet-AHE: Anomalous Hall Effect ,Interference (communication) ,Hall effect ,Patterned media ,Thin film ,Lithography - Abstract
In this paper we present anomalous Hall effect analysis from very thin Co (0.5 nm) film, Co/Pt multilayers and large areas of nanosized dots as well as from a few magnetic dots having a diameter of 120 nm. The dot arrayis prepared from Co/Pt multilayer by using laser interference lithography (LIL) while the Hall crosses for measuring a few dots are prepared in combination with focussed ion beam (FIB). The hysteresis loops from a few dots are showing significant Hall voltage jumps corresponding to magnetic response due to an inhomogeneous reversal mechanism because the intensityof the jumps is smaller than the expected value from a total magnetization reversal of one dot.
- Published
- 2005
12. Progressive encephalomyelitis with rigidity as refractory asthma
- Author
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K Ishii, Y Ishii, T Wada, Kiyohisa Sekizawa, A Nomura, N Kikuchi, and H Harada
- Subjects
Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,business.industry ,Encephalomyelitis ,Stridor ,Avascular necrosis ,medicine.disease ,respiratory tract diseases ,Surgery ,Chronic disease ,immune system diseases ,Prednisolone ,medicine ,Refractory asthma ,medicine.symptom ,business ,Letter to the Editor ,Stiff person syndrome ,medicine.drug ,Asthma - Abstract
Refractory asthma may include diseases other than bronchial asthma.1 We report a 19 year old woman with stridor who developed progressive encephalomyelitis with rigidity (PER). The patient had been undergoing treatment with prednisolone for a diagnosis of refractory asthma but she stopped taking steroids in March 1999 due to avascular necrosis of the femoral heads. She was admitted …
- Published
- 2003
13. Improvement of the retrieval algorithm for GOSAT SWIR XCO2 and XCH4 and their validation using TCCON data.
- Author
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Y. Yoshida, N. Kikuchi, I. Morino, O. Uchino, S. Oshchepkov, A. Bril, T. Saeki, N. Schutgens, Toon, G.C., D. Wunch, Roehl, C. M., Wennberg, P. O., Griffith, D. W. T., Deutscher, N. M., Warneke, T., Notholt, J., Robinson, J., Sherlock, V., Connor, B., and Rettinger, M.
- Subjects
- *
CARBON dioxide , *METHANE , *GREENHOUSE gases , *SPECTRAL sensitivity , *SPECTRAL irradiance - Abstract
The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO2 and XCH4) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the National Institute for Environmental Studies (NIES). XCO2 and XCH4 retrieved using the version 01.xx retrieval algorithm showed large negative biases and standard deviations (-8.85 and 4.75 ppm for XCO2 and -20.4 and 18.9 ppb for XCH4, respectively) compared with data of the Total Carbon Column Observing Network (TCCON). Multiple reasons for these error characteristics (e.g., solar irradiance database, handling of aerosol scattering) are identified and corrected in a revised version of the retrieval algorithm (version 02.xx). The improved retrieval algorithm shows much smaller biases and standard deviations (-1.48 and 2.09 ppm for XCO2 and -5.9 and 12.6 ppb for XCH4, respectively) than the version 01.xx. Also, the number of post-screened measurements is increased, especially at northern mid- and high-latitudinal areas. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
14. Characterization of electronic structure of superconducting (Cu, C)-Ba-O films by in situ photoemission spectroscopy.
- Author
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K Kikunaga, K Takeshita, T Yamamoto, T Okuda, Y Tanaka, N Kikuchi, K Tokiwa, T Watanabe, A Sunderesan, and N Terada
- Subjects
THIN films ,SURFACES (Technology) ,ATOMIC structure ,ELECTRONIC structure - Abstract
Change of electronic structure of superconducting (Cu, C)-1201 thin films grown by pulsed laser deposition with superconducting critical temperature Tc has been characterized by means of in situ photoemission spectroscopy. The finite spectral weight at the Fermi level in the valence band of (Cu, C)-1201 superconducting thin films and a rigid-band-like approach of the main peak of the valence band toward the Fermi level with a rise of Tc has been observed, which reveals hole-doping-induced superconductivity of this system. The obtained Ba 4d and Cu 2p signals with an increase of Tc suggest excess oxygen should be introduced around Ba ions in the early stage of the emergence of superconductivity. Then, they should be preferentially introduced around Cu ions. The changes of core signals with Tc and comparisons of the obtained data with infinite-layer and other cuprate superconductor compounds suggest that the (Cu, C)-O charge reservoir in this system is in the heavily hole-doped state, similar to that of the Cu-O chain in YBa2Cu3O7[?]d. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
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15. Limited VH gene usage in B-cell clones established with nurse-like cells from patients with rheumatoid arthritis.
- Author
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S. Nakamura-Kikuoka, K. Takahi, H. Tsuboi, T. Toyosaki-Maeda, M. Maeda-Tanimura, C. Wakasa, N. Kikuchi, S. Norioka, M. Iwasaki, T. Matsutani, T. Itoh, S. Yamane, H. Takemoto, Y. Tsuruta, Y. Shimaoka, M. Yukioka, R. Suzuki, and T. Ochi
- Published
- 2006
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16. Characteristics of NeXe microplasma in unit discharge cell of plasma display panel equipped with counter sustain electrodes and auxiliary electrodes.
- Author
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K Tachibana, S Kawai, H Asai, and N Kikuchi and S Sakamoto
- Subjects
ELECTRIC resistors ,ELECTRODES ,INDUSTRIAL productivity ,RESONANCE - Abstract
The performance of a new structure plasma display panel (PDP) cell with counter sustain electrodes was diagnosed by optical emission and laser absorption spectroscopic measurements of the spatiotemporal behaviours of the microplasma. Two different types of panels were prepared: one with sustain electrodes only and the other with additional data and auxiliary electrodes on the rear and front plates. By using cells of the former type, the basic performance was measured as the dependences on the Xe concentration in Ne, the total pressure and the applied sustain voltage. It was seen that a higher Xe concentration was advantageous for the luminous efficiency although the required minimum sustain voltage became larger. By using the latter type of cell, the effects of driving schemes were investigated by varying the applied potentials onto the auxiliary and data electrodes. It was found that the role of the auxiliary electrode is remarkable; the discharge expands largely in the cell when the voltage and the width of the pulses applied to the auxiliary electrode are optimized to be 200 V and 0.3 µs, respectively, while the data electrode is grounded. The production efficiency of Xe atoms in the metastable (1s
5 ) and resonance (1s4 ) states was derived from the measured absolute densities normalized by the input power per cell and the decay rates of those densities. The vacuum ultraviolet emission efficiency estimated from the results was compared between the tested conditions, and a noticeable improvement was recognized in the optimized condition, about 40% larger than a conventional driving condition without additional pulses. It was also seen that this cell structure is potentially superior in luminous efficiency to the conventional coplanar structure currently used in commercial PDPs. [ABSTRACT FROM AUTHOR]- Published
- 2005
- Full Text
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17. Interface study and boundary smoothing on designed composite material microstructures for manufacturing purposes.
- Author
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H. Qi, N. Kikuchi, and J. Mazumder
- Published
- 2004
- Full Text
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18. Convergence of Rothe's Method in Hölder Spaces.
- Author
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N. Kikuchi and J. Kačur
- Subjects
STOCHASTIC convergence ,LIPSCHITZ spaces ,PARABOLIC differential equations ,FUNCTION spaces ,PARTIAL differential equations - Abstract
The convergence of Rothe's method in Hölder spaces is discussed. The obtained results are based on uniform boundedness of Rothe's approximate solutions in Hölder spaces recently achieved by the first author. The convergence and its rate are derived inside a parabolic cylinder assuming an additional compatibility conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2003
19. Study on cross-phase modulation (XPM) effect on amplitude and differentially phase-modulated multilevel signals in DWDM transmission.
- Author
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N. Kikuchi, K. Sekine, S. Sasaki, and T. Sugawara
- Abstract
The characteristic degradation mechanism of the cross-phase modulation (XPM) effect on multilevel amplitude and differentially phase-shift keying (APSK) signals in dense wavelength-division-multiplexing (DWDM) transmissions is analyzed and experimentally investigated, for the first time. Based on the results, we successfully demonstrate a 0.48-Tb/s (30-Gb/s/ch) 50-GHz-spaced 16-channel DWDM 160-km unrepeatered transmission of eight-level APSK signals suppressing the XPM-induced degradation. [ABSTRACT FROM PUBLISHER]
- Published
- 2005
- Full Text
- View/download PDF
20. Performance of chromatic dispersion monitoring using statistical moments of asynchronously sampled waveform histograms.
- Author
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N. Kikuchi, S. Hayase, K. Sekine, and S. Sasaki
- Abstract
The performance of the chromatic dispersion monitoring method using statistical moments of asynchronously sampled waveform histograms is investigated in detail. We show its robustness against signal-to-noise ratio degradation and its wide monitoring range using experiments and a newly developed numerical simulation method. We also show the effectiveness of radio frequency bandwidth reduction of the waveform monitor to widen its monitoring range, and also estimate its performance with duobinary and return-to-zero modulation formats. [ABSTRACT FROM PUBLISHER]
- Published
- 2005
- Full Text
- View/download PDF
21. Monolithically integrated 100-channel WDM channel selector employing low-crosstalk AWG.
- Author
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N. Kikuchi, Y. Shibata, H. Okamoto, Y. Kawaguchi, S. Oku, Y. Kondo, and Y. Tohmori
- Abstract
A 100-channel wavelength-division-multiplexing channel selector monolithically integrated on an InP substrate is demonstrated. The selector consists of two arrayed waveguide gratings (AWGs), two semiconductor-optical-amplifier (SOA)-gate arrays, and a multimode interference coupler. The selector employs improved AWGs whose crosstalk is reduced with higher order mode filters. Successful channel selection and lossless operation for all channels are achieved. Error-free operation at 10 Gb/s and small sensitivity penalties between 1.8 and 3.3 dB are obtained. [ABSTRACT FROM PUBLISHER]
- Published
- 2004
- Full Text
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22. Raman fiber oscillator as optical amplifier.
- Author
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S.S.-H. Yam, M.E. Marhic, Y. Akasaka, K. Shimizu, N. Kikuchi, and L.G. Kazovsky
- Abstract
A Raman fiber oscillator used for optical amplification is demonstrated to have lower double Rayleigh scattering, transient spikes, cross-phase modulation, and higher saturation input threshold compared with a conventional discrete Raman amplifier at similar operating conditions. This could be a promising technology for deployment in practical systems. [ABSTRACT FROM PUBLISHER]
- Published
- 2004
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23. Novel in-service wavelength-band upgrade scheme for fiber Raman amplifier.
- Author
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N. Kikuchi, K.K.-Y. Wong, K. Uesaka, K. Shimizu, S. Yam, E.S.-T. Hu, M. Marhic, and L.G. Kazovsky
- Abstract
To reduce the initial introduction cost of fiber Raman amplifiers, a novel in-service wavelength-band upgrade scheme is proposed. In this scheme, new pump lasers are added to an existing Raman amplifier already carrying wavelength-division-multiplexing (WDM) signals, and all the pump laser driving currents are changed synchronously through the transient period, keeping the WDM signal gain unchanged, while increasing the gain in the new band. We experimentally proved the principle of the proposed scheme in both discrete and distributed Raman amplifiers, even with the existence of signal-gain saturation, nonlinear pump interaction, and pump power loss. We also confirmed error-free wavelength-band upgrade in an eight-channel-WDM transmission system. [ABSTRACT FROM PUBLISHER]
- Published
- 2003
- Full Text
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24. Thermally induced switching field distribution of a single CoPt dot in a large array.
- Author
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J B C Engelen, M Delalande, A J le, T Bolhuis, T Shimatsu, N Kikuchi, L Abelmann, and J C Lodder
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BINARY metallic systems ,MICROFABRICATION ,ANISOTROPY ,MAGNETIC properties of thin films ,LITHOGRAPHY ,HALL effect ,HYSTERESIS - Abstract
Magnetic dot arrays with perpendicular magnetic anisotropy were fabricated by patterning Co80Pt20-alloy continuous films by means of laser interference lithography. As commonly seen in large dot arrays, there is a large difference in the switching field between dots. Here we investigate the origin of this large switching field distribution, by using the anomalous Hall effect (AHE). The high sensitivity of the AHE permits us to measure the magnetic reversal of individual dots in an array of 80 dots with a diameter of 180 nm. By taking 1000 hysteresis loops we reveal the thermally induced switching field distribution SFDT of individual dots inside the array. The SFDT of the first and last switching dots were fitted to an Arrhenius model, and a clear difference in switching volume and magnetic anisotropy was observed between dots switching at low and high fields. [ABSTRACT FROM AUTHOR]
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- 2010
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25. Usefulness of decision tree analysis of MRI features for diagnosis of placenta accreta spectrum in cases with placenta previa.
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Tanaka Y, Ando H, Miyamoto T, Yokokawa Y, Ono M, Asaka R, Kobara H, Fuseya C, Kikuchi N, Ohya A, Fujinaga Y, and Shiozawa T
- Abstract
Purpose: Placenta previa complicated by placenta accrete spectrum (PAS) is a life-threatening obstetrical condition; therefore, preoperative diagnosis of PAS is important to determine adequate management. Although several MRI features that suggest PAS has been reported, the diagnostic importance, as well as optimal use of each feature has not been fully evaluated., Materials and Methods: The occurrence of 11 PAS-related MRI features was investigated in MR images of 145 patients with placenta previa. The correlation between each MRI feature and pathological diagnosis of PAS was evaluated using univariate analysis. A decision tree model was constructed according to a random forest machine learning model of variable selection., Results: Eight MRI features showed a significant correlation with PAS in univariate analysis. Among these features, placental/uterine bulge and myometrial thinning showed high odds ratios: 138.2 (95% CI: 12.7-1425.6) and 66.0 (95% CI: 18.01-237.1), respectively. A decision tree was constructed based on five selected MRI features: myometrial thinning, placental bulge, serosal hypervascularity, placental ischemic infarction/recess, and intraplacental T2 dark bands. The decision tree predicted the presence of PAS in the randomly assigned validation cohort with significance (p < 0.001). The sensitivity and the specificity of the decision tree for detecting PAS were 90.0% (95%CI: 53.2-98.9) and 95.5% (95%CI: 89.9-96.8), respectively., Conclusion: Among PAS-related MRI features, placental/uterine bulge and myometrial thinning showed high diagnostic values. In addition, the present decision tree model was shown to be effective in predicting the presence of PAS in cases with placenta previa., (© 2024. The Author(s).)
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- 2024
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26. Male Sex Is an Associated Factor for Delayed Bone Union Following Hybrid Closed-Wedge High Tibial Osteotomy.
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Kikuchi N, Arai N, Okuno K, and Kanamori A
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- Humans, Male, Female, Middle Aged, Retrospective Studies, Aged, Sex Factors, Tomography, X-Ray Computed methods, Osteotomy methods, Tibia surgery, Osteoarthritis, Knee surgery
- Abstract
Background and Objectives : Although hybrid closed-wedge high tibial osteotomy (HTO) is an effective procedure for varus knee osteoarthritis, delayed bone union is a frequent occurrence. The rate of bone union and its associated factors remain unclear. This study aimed to investigate the detailed process of bone union in hybrid closed-wedge HTO using computed tomography (CT) and to examine factors associated with delayed bone union. Materials and Methods : We retrospectively reviewed 53 consecutive patients who underwent hybrid closed-wedge HTO. Cases with no bone union at any of five sites (anterior flange, posterior, lateral, hinge, and medial) on coronal and sagittal computed tomography at 3 months postoperatively were defined as delayed bone union. Regression analysis was performed with delayed bone union as the dependent variable and sex, age, height, body weight, body mass index, correction distance, smoking, and diabetes mellitus as independent variables. Results : Among 50 analyzed knees (mean age, 61.4 ± 7.8 years), 17 (34.0%) had delayed bone union at 3 months postoperatively and one knee had screw breakage. Sex was the only significant factor associated with delayed bone union (male: β = 2.1, p < 0.004). Conclusions : Delayed bone union (absence at 3 months after hybrid closed-wedge high tibial osteotomy) occurred in 34% of patients, and male sex was associated with delayed bone union., Competing Interests: The authors declare no conflicts of interest.
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- 2024
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27. Prognostic Factors for Patients with Small-Cell Lung Cancer Treated with Chemoimmunotherapy: A Retrospective Multicenter Study.
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Hatori T, Numata T, Shiozawa T, Taguchi M, Sakurai H, Tamura T, Kanazawa J, Tachi H, Kondo K, Miyazaki K, Kikuchi N, Kurishima K, Satoh H, and Hizawa N
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- Humans, Male, Female, Prognosis, Retrospective Studies, Aged, Middle Aged, Aged, 80 and over, Adult, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Small Cell Lung Carcinoma drug therapy, Small Cell Lung Carcinoma pathology, Small Cell Lung Carcinoma therapy, Lung Neoplasms drug therapy, Lung Neoplasms pathology, Immunotherapy methods
- Abstract
Background: This study aimed to investigate prognostic factors for predicting the survival of patients with extensive-disease-stage small-cell lung cancer treated with chemoimmunotherapy., Methods: Patients were classified according to overall survival (OS): favorable corresponded to an OS ≥ 24 months, moderate corresponded to an OS of 6-24 months, and poor corresponded to an OS < 6 months. Multivariate Cox regression analyses were used to evaluate prognostic factors., Results: Of 130 patients, the proportions of performance status decline and liver metastasis were significantly higher in the poor-prognosis group. With regard to the laboratory findings, neutrophil/lymphocyte ratios and albumin levels differed significantly among the groups. Multivariate analysis showed that the independent prognostic factors for OS were liver metastasis and decreased albumin levels (<3.5 mg/dL). After classifying the patients into three groups according to the quantities of these prognostic factors, the OS differed significantly among the groups (18.3 vs. 13.5 vs. 3.8 months; p < 0.001). The incidence of immune-related adverse events (irAEs) was higher in patients without these prognostic factors than in those with both (36% vs. 5%; p = 0.01)., Conclusion: Liver metastasis and decreased albumin levels are independent unfavorable prognostic factors. Patients with both prognostic factors showed unfavorable OS; however, patients without these factors may have a favorable prognosis but be at greater risk of irAEs.
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- 2024
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28. Maternal Serum and Cord Blood Levels of Levetiracetam and Valproate at Delivery and Their Associations With Neonatal Abstinence-Related Symptoms.
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Ozawa S, Matsuzawa N, Fuseya C, Kikuchi N, Shiozawa T, and Naito T
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Competing Interests: The authors declare no conflict of interest.
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- 2024
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29. Cold Environment-Associated Extremity Lesions or Severe Hypothermia Help Differentiate Between Frostbitten and Trench Foot (Immersion Foot).
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Suito M, Yanagida T, Ohtsubo M, Tsunekawa K, and Kikuchi N
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Cold associated foot injuries, such as frostbite and trench foot (immersion foot) are relatively common in cold environments. The former is classified as a freezing cold injury, and the latter as a nonfreezing cold injury. Trench foot is sometimes misdiagnosed as frostbite, and rapid rewarming exacerbates the condition. This paper aims to help differentiate between frostbitten foot and trench foot. This study included patients with frostbitten foot or trench foot treated at our hospital between December 2005 and May 2023. The differences in sex, age, month of injury, conditions at the time of injury, injury distribution, foot lesion laterality, other complications upon arrival (finger frostbite, immersion hand, or hypothermia), and presence and distribution of sensory disturbance at discharge were noted among the groups. A total of 16 patients (14 men) with frostbitten foot and 3 patients (3 men) with trench foot were identified. Finger frostbite observed in nine and zero patients with frostbitten foot and trench foot, respectively; and severe hypothermia on arrival observed in five and zero patients with frostbitten foot and trench foot, respectively. Physical findings at the initial examination showed that the frostbitten feet were dry, and the lesions were distal and clearly demarcated, whereas feet with trench foot were wet, and the lesions covered the entire sole and were not clearly demarcated. Accurate differentiation between frostbitten foot and trench foot and appropriate initial treatment are important. The presence of finger frostbite, immersion hand or severe hypothermia may help to differentiate between frostbitten foot and trench foot., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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- 2024
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30. Muscle Performance as a Predictor of Bone Health: Among Community-Dwelling Postmenopausal Japanese Women from Setagaya-Aoba Study.
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Ohta T, Sasai H, Kikuchi N, Nakazato K, and Okamoto T
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- Adult, Aged, Aged, 80 and over, Female, Humans, Middle Aged, East Asian People, Japan, Osteoporosis, Postmenopausal diagnosis, Osteoporosis, Postmenopausal epidemiology, Osteoporosis, Postmenopausal diagnostic imaging, Bone Density physiology, Muscle, Skeletal physiology, Postmenopause physiology
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Osteoporosis is a significant health concern for postmenopausal women, necessitating efficient screening methods for bone health. This study explores the potential of muscle function, assessed through the 30-s chair stand test (CS-30), as an indicator for low bone stiffness in this demographic, aiming to establish a practical threshold for large-scale fitness surveillance without the need for specialized tools. We analyzed data from 1055 community-dwelling postmenopausal Japanese women, aged 41-89 years, collected between 2016 and 2019. Participants underwent CS-30 to evaluate muscle function alongside quantitative ultrasound (QUS) measurements to assess bone stiffness. The cohort was divided into two groups for the development and validation of a cutoff point for low bone stiffness, defined as a QUS speed of sound less than 1487.3 m/s. The CS-30 cutoff was determined using receiver operating characteristic (ROC) curve analysis and validated through logistic regression, accounting for age, body mass index, and smoking status. Among 577 postmenopausal women, 16.0% exhibited low bone stiffness. In the development group (n = 382), ROC analysis identified a CS-30 cutoff of 25 repetitions for detecting low bone stiffness, with an area under the curve of 0.744 (P < 0.001). In the validation group (n = 195), participants performing ≥ 25 repetitions had a higher risk of low bone stiffness compared to those performing ≤ 24 repetitions. The CS-30 test is an effective preliminary screening tool for identifying postmenopausal women at risk of low bone stiffness, with a threshold of 25 repetitions. This method could facilitate early detection of individuals at higher osteoporosis risk, promoting timely intervention., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2024
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31. Morphological and Chemical Diversity within Japanese Laurencia Complex (Rhodomelaceae, Ceramiales, Rhodophyta).
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Yamagishi Y, Kamada T, Ishii T, Matsuura H, Kikuchi N, Abe T, and Suzuki M
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- Japan, Rhodophyta chemistry, Rhodophyta classification, Laurencia chemistry
- Abstract
Seaweeds of the red algal genus Laurencia are distributed worldwide in tropical, subtropical to temperate zones, growing in Japan from Hokkaido to Okinawa. Laurencia is highly difficult to classify morphologically because of a high degree of morphological variation within individual species. Nevertheless, Laurencia investigation is favored by organic chemists as it produces uniquely structured compounds. Halogenated secondary metabolites are considered to be used as chemical markers for chemical systematics (chemotaxonomy) of this troublesome genus. As a "weedy seaweed", Laurencia is not effectively utilized, yet it produces a variety of metabolites and thus, holds good potential for containing compounds with specific activity, especially in aspects of secondary metabolites. In this review, we reported significant morphological features to distinguish species in this genus, and the morphological features, habitat, distribution, and chemical composition that help discriminate Japanese Laurencia species., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)
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- 2024
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32. Dual-source photon-counting computed tomography for coronary in-stent observation: influence of heart rate and virtual monoenergetic image.
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Ogawa R, Yanagawa M, Hata A, Yamagata K, Ninomiya K, Doi S, Kikuchi N, Tokuda Y, Chimura M, Nakamura D, Itoh T, Kido T, and Tomiyama N
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- Humans, Prosthesis Design, Percutaneous Coronary Intervention instrumentation, Coronary Restenosis diagnostic imaging, Coronary Restenosis etiology, Coronary Restenosis physiopathology, Coronary Stenosis diagnostic imaging, Coronary Stenosis physiopathology, Reproducibility of Results, Photons, Heart Rate, Stents, Phantoms, Imaging, Coronary Vessels diagnostic imaging, Coronary Vessels physiopathology, Predictive Value of Tests, Coronary Angiography, Radiographic Image Interpretation, Computer-Assisted, Computed Tomography Angiography
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To investigate the effect of heart rate and virtual monoenergetic image (VMI) on coronary stent imaging in dual-source photon-counting detector computed tomography (PCD-CT). A dynamic cardiac phantom was used to vary the heart rate at 50 beats per minute (bpm), 70 bpm, and 90 bpm. Five types of stents (4.0 mm, 3.5 mm, 3.0 mm, 2.75 mm, and 2.5 mm diameter) were scanned at three different locations and reconstructed VMI at 70 keV. In addition, 50% stenosis was assessed for 3.0 mm and 4.0 mm stents. To assess in-stent stenosis, 40 keV, 70 keV, and 100 keV images were compared. Measurable lumen and contrast to noise ratio (CNR) from lumen to stenosis were evaluated quantitatively. A-4-point scale was used for the qualitative image quality of in-stent stenosis. The measurable lumen had no significant differences among heart rates in patent stents (p = 0.55). In-stent stenosis, the residual lumen was significantly larger in 40 keV [27.5% (20.8-32.3%)] than in 70 keV [11.5% (10.0-23.0%), p < 0.05] and 100 keV [0% (0-5.2%), p < 0.05]. The CNR was higher in 40 keV [12.5 (7.5-18.2)] than in 70 keV [5.3 (2.9-7.7), p < 0.05] and 100 keV [1.3 (0.5-2.7), p < 0.05]. The image quality was better in 40 keV (3.4 ± 0.7) than in 70 keV [(2.6 ± 0.8), p < 0.05] and 100 keV [(1.3 ± 0.4), p < 0.05]. Dual-source PCD-CT maintains a measurable lumen even at high heart rates. Adjusting the VMI can be helpful in visualizing the in-stent stenosis., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)
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- 2024
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33. Prognostic impact of outpatient loop diuretic reduction patterns in patients with chronic heart failure.
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Koike T, Suzuki A, Kikuchi N, Yoshimura A, Haruki K, Yoshida A, Sone M, Nakazawa M, Tsukamoto K, Imamura Y, Hattori H, Kogure T, Yamaguchi J, and Shiga T
- Abstract
Background: The relationship between patterns of outpatient oral loop diuretic (LD) dose reduction and prognosis in patients with heart failure (HF) remains unclear., Methods: We evaluated 679 patients with HF-prescribed LDs at baseline between September 2015 and August 2019. Dose reduction was defined as a change to a lower LD dose than the previous outpatient dose. Dose intensification was defined as a change to a higher LD dose than the previous outpatient dose. Patients were classified into no-reduction (no LD dose reduction during follow-up) and reduction groups (categorized into successive-reduction [≥2 successive LD dose reductions without intervening LD dose intensification] and single-reduction [LD dose reduction without successive dose reduction] groups). The primary outcomes were all-cause death, HF hospitalization (HFH), and the composite of cardiovascular death (CVD) or HFH., Results: Within a median follow-up of 53.7 (range, 2.6-99.1) months, 156 deaths were recorded: 121 (29 %), 31 (15 %), and three (4 %) patients in the no-reduction (n = 411), single-reduction (n = 195), and successive-reduction (n = 73) groups, respectively. After adjusting for cofounders, the reduction group had a lower risk of primary outcomes than the no reduction group (all-cause death: hazard ratio (HR) = 0.65, 95 % confidence interval (CI) = 0.44-0.96; CVD or HFH: HR=0.69, 95 %CI=0.52-0.93; HFH: HR=0.69, 95 % CI=0.52-0.93). The successive-reduction group had a lower risk of the composite of CVD or HFH (HR=0.26, 95 % CI: 0.10-0.67) and HFH (HR=0.34, 95 % CI=0.13-0.86) than the single-reduction group., Conclusions: Outpatient LD dose reduction patterns can be indicators of good prognosis in HF patients., Competing Interests: 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., (© 2024 The Author(s).)
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- 2024
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34. Effect of the ACTN3 R577X Polymorphism on Serum Creatine Kinase and Interleukin-6 Levels after Maximal Eccentric Exercise.
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Deguchi M, Homma H, de Almeida KY, Kozuma A, Saito M, Tsuchiya Y, Kouzaki K, Ochi E, Okamoto T, Nakazato K, and Kikuchi N
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Objective: This study explored the interaction among ACTN3 R577X polymorphism, muscle damage, and post-exercise inflammatory response by assessing changes over time in serum creatine kinase and interleukin-6 levels., Design: Ninety-five active Japanese participants (50 men and 45 women: 22.2 ± 2.3 years) who did not perform daily upper limb strength exercises were enrolled. Participants executed five sets of six maximal eccentric elbow flexion exercises. The exercise duration was 9 min, including rest between sets (90 s). Maximum voluntary isometric contraction, range of motion, muscle soreness, and serum creatine kinase and interleukin-6 levels were assessed pre and post and 1, 2, 3, and 5 d after exercise. Genotype groups were classified as RR + RX and XX based on the absence of ACTN3 expression., Results: A significant time and group interaction (p = 0.045) on creatine kinase levels was observed between the groups, indicating that the absence of ACTN3 significantly affects creatine kinase changes. Conversely, no significant interaction on change in interleukin-6, maximum voluntary isometric contraction, range of motion, and muscle soreness was observed between groups., Conclusion: The results highlight an interaction on creatine kinase activity post-exercise by ACTN3 R577X polymorphism, with elevated activity in the XX genotype., Competing Interests: The authors certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)
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- 2024
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35. Cardiogenic shock severity predicts bleeding events in patients with temporary mechanical circulatory support.
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Oyabu K, Hattori H, Kikuchi N, Haruki S, Minami Y, Ichihara Y, Saito S, Nunoda S, Niinami H, and Yamaguchi J
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Background: Data on shock severity and bleeding events in patients with temporary mechanical circulatory support (tMCS) are limited. We investigated the relationship between the Society for Cardiovascular Angiography and Interventions (SCAI) shock stage classification and bleeding events in patients with tMCS., Methods: We evaluated the data of 285 consecutive patients with tMCS who were admitted to our institution between June 2019 and May 2022. At the time of tMCS initiation, 81 patients (28.4%) were in SCAI stage A, 38 (13.3%) in stage B, 69 (24.2%) in stage C, 33 (11.6%) in stage D, and 64 (22.5%) in stage E. Multivariable logistic regression modeling was used to assess the association between the SCAI shock stage and in-hospital bleeding events., Results: In-hospital bleeding occurred in 100 patients (35.1%). The bleeding event rate increased incrementally across the SCAI shock stages (stage A, 11.1%; stage B, 15.8%; stage C, 37.7%; stage D, 54.6%; stage E, 64.1%). In-hospital bleeding was associated with the SCAI shock stage (p < 0.001). Compared with stage A, the adjusted odds ratios for in-hospital bleeding were 1.48 (95% confidence interval [CI] 0.47-4.66), 6.47 (95% CI 2.61-10.66), 11.59 (95% CI 3.77-35.64), and 7.85 (95% CI 2.51-24.55) for stages B, C, D, and E, respectively., Conclusions: The SCAI shock stage predicted subsequent bleeding events in patients with tMCS. This simple scheme may be useful for tailored risk-based clinical assessment and management of patients with tMCS., (© 2024 Wiley Periodicals LLC.)
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- 2024
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36. Effect of platelet-rich plasma on the acceleration of graft bone catabolism in lateral lumbar interbody fusion in a short-term assessment.
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Sato K, Funayama T, Noguchi H, Kumagai H, Kikuchi N, Yoshioka T, Koda M, and Yamazaki M
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- Humans, Male, Female, Middle Aged, Aged, Tomography, X-Ray Computed, Adult, Spinal Fusion methods, Platelet-Rich Plasma, Bone Transplantation methods, Lumbar Vertebrae surgery
- Abstract
This study aimed to demonstrate whether impregnating the graft bone with platelet-rich plasma (PRP) accelerates graft bone catabolism in lateral lumbar interbody fusion (LLIF). Consecutive patients who underwent LLIF were assessed. Of the two spaces for bone grafts in the intervertebral cage, one space was filled with graft bone impregnated with PRP, and the other was filled with graft bone without PRP, which divided the graft bones into PRP and non-PRP groups. The mean Hounsfield units (HU) of the graft bone at the center of the cage space in the coronal and axial slices were measured using computed tomography (CT) images 1 week and 6 months after surgery. The delta value of HU from 1 week to 6 months after surgery was calculated for the PRP and non-PRP groups. We compared the delta values of the HU between the two groups. The PRP and non-PRP groups comprised 16 bone grafts. In the coronal slices, the HU value in the PRP group (delta value: 526.1 ± 352.2) tended to have a greater decrease at 6 months after surgery compared with that in the non-PRP group (delta value: 217.6 ± 240.4) (p = 0.065). In the axial slices, the HU value in the PRP group (delta value: 501.3 ± 319.6) was significantly decreased at 6 months after surgery compared with that in the non-PRP group (delta value: 159.2 ± 215.3) (p = 0.028). Impregnating the graft-bone with PRP accelerated graft bone catabolism in LLIF within 6 months after surgery., (© 2023. The Japanese Society for Artificial Organs.)
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- 2024
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37. Classification of upper-limb dysfunction severity and prediction of independence in activities of daily living after cervical spinal-cord injury.
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Jimbo K, Miyata K, Yuine H, Takahama K, Yoshimura T, Shiba H, Yasumori T, Kikuchi N, and Shiraishi H
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- Humans, Male, Female, Middle Aged, Adult, Aged, Prospective Studies, Disability Evaluation, Severity of Illness Index, Cervical Cord injuries, Cervical Cord physiopathology, Spinal Cord Injuries physiopathology, Spinal Cord Injuries diagnosis, Spinal Cord Injuries complications, Activities of Daily Living, Upper Extremity physiopathology
- Abstract
Study Design: Prospective observational study., Objectives: Classification of spinal-cord injury and prediction of independence in activities of daily living (ADL) based on performance evaluations such as upper-limb function have not been reported. Therefore, this study aimed to establish a severity classification and calculate cutoff values for independence in ADL using the Capabilities of Upper Extremity Test (CUE-T) for individuals with cervical spinal-cord injury (CSCI)., Setting: A spinal-cord injury rehabilitation center in Japan., Methods: This study included individuals with subacute CSCI. Collected data included the CUE-T and Spinal Cord Independence Measure III (SCIM III) scores. The severity classification was used for the hierarchical cluster analysis using the CUE-T. The cutoff values of CUE-T scores for independence in ADL were calculated using an adjustment model with logistic regression analysis. The dependent variable was binary (independent/non-independent) for each SCIM III Self-care item, and the independent variable was CUE-T., Results: A total of 71 participants were included in the analysis. The severity of upper-limb dysfunction was classified into four categories using CUE-T. Significant differences in upper-limb function and ADL were observed between clusters. The cutoff values for CUE-T score for independence in ADL ranged from 37 to 91 points. All cutoff values showed good results in the internal validation, sensitivity analysis., Conclusions: This study determined the severity of upper limb function in CSCI and the cutoff values of CUE-T scores for independence in ADL. These results may help set criteria and goals for interventions in the clinical and research fields., Sponsorship: None., (© 2024. The Author(s), under exclusive licence to International Spinal Cord Society.)
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- 2024
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38. Correction: Classification of upper-limb dysfunction severity and prediction of independence in activities of daily living after cervical spinal-cord injury.
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Jimbo K, Miyata K, Yuine H, Takahama K, Yoshimura T, Shiba H, Yasumori T, Kikuchi N, and Shiraishi H
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- 2024
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39. Caregivers of patients with long-term implantable ventricular assist device: a republication of the article published in the Japanese Journal of Artificial Organs.
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Kikuchi N
- Subjects
- Humans, Japan, Caregivers, Heart Failure therapy, Heart Failure surgery, Heart-Assist Devices
- Abstract
Implantable ventricular assist device (VAD) has enabled patients with severe heart failure to be discharged from the hospital and to continue their care at home. The presence of caregivers is essential to maintain home care of patients with VAD. The caregivers are mainly the family members who live with the patient with VAD. The caregivers need to be trained (1) VAD device management, (2) disinfection of driveline skin punctures, (3) medication management, and (4) responding to sudden changes. The caregivers' lifestyle is also forced to change. In this article, we discuss the role of caregivers in the VAD era, where long-term support beyond 5 years is now possible. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2023 (Vol. 52, No. 1, pp. 81-84), with some modifications., (© 2024. The Japanese Society for Artificial Organs.)
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- 2024
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40. Varus knee osteoarthritis with ankle osteoarthritis demonstrates greater hindfoot inversion and larger ankle inversion loading during gait following total knee arthroplasty compared to varus knee osteoarthritis alone.
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Kikuchi N, Kanamori A, Kadone H, Okuno K, Hyodo K, and Yamazaki M
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- Humans, Female, Male, Retrospective Studies, Aged, Middle Aged, Biomechanical Phenomena, Osteoarthritis surgery, Osteoarthritis physiopathology, Weight-Bearing physiology, Gait Analysis, Osteoarthritis, Knee surgery, Osteoarthritis, Knee physiopathology, Osteoarthritis, Knee complications, Arthroplasty, Replacement, Knee, Gait physiology, Ankle Joint surgery, Ankle Joint physiopathology
- Abstract
Purpose: Although patients with varus knee osteoarthritis (KOA) and concurrent ankle osteoarthritis (AOA) may experience increased ankle joint pain after total knee arthroplasty (TKA), the underlying mechanism remains unclear. This study aimed to investigate the effects of concurrent AOA on ankle and hindfoot alignment, frontal plane ankle and hindfoot biomechanics during gait following TKA and the clinical outcomes., Methods: Twenty-four patients with varus KOA who underwent TKA were included in this retrospective cohort study. Patients were categorized into two groups: with and without AOA. Radiographic evaluations of lower-limb, ankle and hindfoot alignment, and knee and ankle clinical outcomes were conducted preoperatively and 6 months postoperatively. In addition, gait analyses were performed to investigate knee, ankle and hindfoot kinematics and kinetics. Each data was compared between patients with and without AOA., Results: Concomitant AOA was found in eight ankles. The AOA group exhibited greater postoperative hindfoot varus and increased postoperative ankle pain than the non-AOA group. Gait analysis showed no significant differences in knee varus alignment or tibial tilt after TKA between the groups. However, the AOA group demonstrated significantly greater hindfoot inversion and larger ankle inversion loading., Conclusion: One third of patients who underwent TKA had concurrent AOA associated with hindfoot varus. Despite achieving proper coronal knee alignment postoperatively, these patients experienced greater hindfoot and ankle joint inversion load during gait. Surgeons should consider the inability to evert the hindfoot and the possibility of increased ankle joint pain when planning and performing TKA., Level of Evidence: Level III., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)
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- 2024
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41. Photon-Counting Detector CT Radiological-Histological Correlation in Cadaveric Human Lung Nodules and Airways.
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Hata A, Yanagawa M, Ninomiya K, Kikuchi N, Kurashige M, Masuda C, Yoshida T, Nishigaki D, Doi S, Yamagata K, Yoshida Y, Ogawa R, Tokuda Y, Morii E, and Tomiyama N
- Abstract
Objectives: The aim of this study was to compare the performances of photon-counting detector computed tomography (PCD-CT) and energy-integrating detector computed tomography (EID-CT) for visualizing nodules and airways in human cadaveric lungs., Materials and Methods: Previously obtained 20 cadaveric lungs were scanned, and images were prospectively acquired by EID-CT and PCD-CT at a radiation dose with a noise level equivalent to the diagnostic reference level. PCD-CT was scanned with ultra-high-resolution mode. The EID-CT images were reconstructed with a 512 matrix, 0.6-mm thickness, and a 350-mm field of view (FOV). The PCD-CT images were reconstructed at 3 settings: PCD-512: same as EID-CT; PCD-1024-FOV350: 1024 matrix, 0.2-mm thickness, 350-mm FOV; and PCD-1024-FOV50: 1024 matrix, 0.2-mm thickness, 50-mm FOV. Two specimens per lung were examined after hematoxylin and eosin staining. The CT images were evaluated for nodules on a 5-point scale and for airways on a 4-point scale to compare the histology. The Wilcoxon signed rank test with Bonferroni correction was performed for statistical analyses., Results: Sixty-seven nodules (1321 μm; interquartile range [IQR], 758-3105 μm) and 92 airways (851 μm; IQR, 514-1337 μm) were evaluated. For nodules and airways, scores decreased in order of PCD-1024-FOV50, PCD-1024-FOV350, PCD-512, and EID-CT. Significant differences were observed between series other than PCD-1024-FOV350 versus PCD-1024-FOV50 for nodules (PCD-1024-FOV350 vs PCD-1024-FOV50, P = 0.063; others P < 0.001) and between series other than EID-CT versus PCD-512 for airways (EID-CT vs PCD-512, P = 0.549; others P < 0.005). On PCD-1024-FOV50, the median size of barely detectable nodules was 604 μm (IQR, 469-756 μm) and that of barely detectable airways was 601 μm (IQR, 489-929 μm). On EID-CT, that of barely detectable nodules was 837 μm (IQR, 678-914 μm) and that of barely detectable airways was 1210 μm (IQR, 674-1435 μm)., Conclusions: PCD-CT visualized small nodules and airways better than EID-CT and improved with high spatial resolution and potentially can detect submillimeter nodules and airways., Competing Interests: Conflicts of interest and sources of funding: none declared. The study was supported by a grant from the Grants-in-Aid for Scientific Research–KAKENHI (JP21K07672)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)
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- 2024
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42. Three-dimensional iodine mapping quantified by dual-energy CT for predicting programmed death-ligand 1 expression in invasive pulmonary adenocarcinoma.
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Yamagata K, Yanagawa M, Hata A, Ogawa R, Kikuchi N, Doi S, Ninomiya K, Tokuda Y, and Tomiyama N
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- Humans, Male, Female, Aged, Middle Aged, Imaging, Three-Dimensional methods, Adenocarcinoma of Lung diagnostic imaging, Adenocarcinoma of Lung metabolism, Adenocarcinoma of Lung pathology, Aged, 80 and over, ROC Curve, B7-H1 Antigen metabolism, Tomography, X-Ray Computed methods, Lung Neoplasms metabolism, Lung Neoplasms diagnostic imaging, Lung Neoplasms pathology, Iodine metabolism
- Abstract
We examined the association between texture features using three-dimensional (3D) io-dine density histogram on delayed phase of dual-energy CT (DECT) and expression of programmed death-ligand 1 (PD-L1) using immunostaining methods in non-small cell lung cancer. Consecutive 37 patients were scanned by DECT. Unenhanced and enhanced (3 min delay) images were obtained. 3D texture analysis was performed for each nodule to obtain 7 features (max, min, median, mean, standard deviation, skewness, and kurtosis) from iodine density mapping and extracellular volume (ECV). A pathologist evaluated a tumor proportion score (TPS, %) using PD-L1 immunostaining: PD-L1 high (TPS ≥ 50%) and low or negative expression (TPS < 50%). Associations between PD-L1 expression and each 8 parameter were evaluated using logistic regression analysis. The multivariate logistic regression analysis revealed that skewness and ECV were independent indicators associated with high PD-L1 expression (skewness: odds ratio [OR] 7.1 [95% CI 1.1, 45.6], p = 0.039; ECV: OR 6.6 [95% CI 1.1, 38.4], p = 0.037). In the receiver-operating characteristic analysis, the area under the curve of the combination of skewness and ECV was 0.83 (95% CI 0.67, 0.93) with sensitivity of 64% and specificity of 96%. Skewness from 3D iodine density histogram and ECV on dual energy CT were significant factors for predicting PD-L1 expression., (© 2024. The Author(s).)
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- 2024
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43. The Effectiveness of Leukocyte-Poor Platelet-Rich Plasma Injections for Symptomatic Mild to Moderate Osteoarthritis of the Knee With Joint Effusion or Bone Marrow Lesions in a Japanese Population: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.
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Yoshioka T, Arai N, Sugaya H, Taniguchi Y, Kanamori A, Gosho M, Okuno K, Kikuchi N, Hyodo K, Aoto K, and Yamazaki M
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- Humans, Male, Female, Double-Blind Method, Middle Aged, Injections, Intra-Articular, Aged, Japan, Magnetic Resonance Imaging, Pain Measurement, Treatment Outcome, Knee Joint, Bone Marrow, East Asian People, Osteoarthritis, Knee therapy, Platelet-Rich Plasma
- Abstract
Background: Intra-articular platelet-rich plasma (PRP) injections have been proposed for the treatment of knee osteoarthritis (OA); however, their effectiveness in Japanese patients remains unclear., Purpose: To investigate whether 3 intra-articular injections of leukocyte-poor PRP (LP-PRP) improve symptoms and joint function in symptomatic Japanese patients with mild to moderate knee OA., Study Design: Randomized controlled trial; Level of evidence, 1., Methods: Of 72 patients screened, 30 were included and randomized to receive LP-PRP (n = 15) or saline (placebo; n = 15) injections between March 2019 and February 2023. Patients attended a screening visit and 3 treatment visits at 1 week apart, followed by 3 follow-up visits (at 4, 12, and 24 weeks) after the initial treatment visit. The primary efficacy outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, whereas the secondary efficacy outcome measures were the proportion of patients showing a visual analog scale (VAS) improvement of ≥50%. Magnetic resonance imaging was performed to evaluate joint effusion and bone marrow lesions using the Whole-Organ Magnetic Resonance Imaging Score. Patients were followed for 24 weeks., Results: Patients in the PRP group (mean age, 65.9 years) had a mean hip-knee-ankle angle of 5.1°, with 7 and 8 patients demonstrating Kellgren-Lawrence grade 2 and 3 knee OA, respectively. Patients in the placebo group (mean age, 67.9 years) had a mean hip-knee-ankle angle of 3.8°, with 6 and 9 patients showing Kellgren-Lawrence grade 2 and 3 knee OA, respectively. No significant differences were identified in any baseline factors. The percentage change in Western Ontario and McMaster Universities Osteoarthritis Index scores from baseline to 24 weeks was significantly different (P= .032) between the PRP (median, 75.9%; quantile 1 [Q1], 49.6; quantile 3 [Q3], 94.1]) and placebo (median, 27.7%; Q1, -9.4; Q3, 80.9]) groups. Overall, 73.3% and 28.6% of the PRP group and placebo group, respectively, exhibited an improvement in visual analog scale scores of ≥50%, with a significant improvement observed in the PRP group ( P = .027). Changes in bone marrow lesions from baseline to 24 weeks, as assessed on magnetic resonance imaging, significantly differed between groups ( P = .017), with no significant differences in other secondary endpoints., Conclusion: In Japanese patients with knee OA, 3 intra-articular LP-PRP injections led to clinical improvements at 24-week follow-up and significant functional improvements and pain relief after 24 weeks., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This study was funded by a grant for the implementation of advanced medicine from the University of Tsukuba Hospital (No. TRM2019-06). AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
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- 2024
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44. Association between interstitial lung abnormality and mortality in patients with esophageal cancer.
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Hata A, Yanagawa M, Miyata T, Hiraoka Y, Shirae M, Ninomiya K, Doi S, Yamagata K, Yoshida Y, Kikuchi N, Ogawa R, Hatabu H, and Tomiyama N
- Subjects
- Humans, Male, Female, Aged, Retrospective Studies, Tomography, X-Ray Computed methods, Middle Aged, Esophageal Neoplasms mortality, Esophageal Neoplasms complications, Esophageal Neoplasms diagnostic imaging, Lung Diseases, Interstitial diagnostic imaging, Lung Diseases, Interstitial mortality, Lung Diseases, Interstitial complications
- Abstract
Purpose: To investigate the relationship between interstitial lung abnormalities (ILAs) and mortality in patients with esophageal cancer and the cause of mortality., Materials and Methods: This retrospective study investigated patients with esophageal cancer from January 2011 to December 2015. ILAs were visually scored on baseline CT using a 3-point scale (0 = non-ILA, 1 = indeterminate for ILA, and 2 = ILA). ILAs were classified into subcategories of non-subpleural, subpleural non-fibrotic, and subpleural fibrotic. Five-year overall survival (OS) was compared between patients with and without ILAs using the multivariable Cox proportional hazards model. Subgroup analyses were performed based on cancer stage and ILA subcategories. The prevalences of treatment complications and death due to esophageal cancer and pneumonia/respiratory failure were analyzed using Fisher's exact test., Results: A total of 478 patients with esophageal cancer (age, 66.8 years ± 8.6 [standard deviation]; 64 women) were evaluated in this study. Among them, 267 patients showed no ILAs, 125 patients were indeterminate for ILAs, and 86 patients showed ILAs. ILAs were a significant factor for shorter OS (hazard ratio [HR] = 1.68, 95% confidence interval [CI] 1.10-2.55, P = 0.016) in the multivariable Cox proportional hazards model adjusting for age, sex, smoking history, clinical stage, and histology. On subgroup analysis using patients with clinical stage IVB, the presence of ILAs was a significant factor (HR = 3.78, 95% CI 1.67-8.54, P = 0.001). Subpleural fibrotic ILAs were significantly associated with shorter OS (HR = 2.22, 95% CI 1.25-3.93, P = 0.006). There was no significant difference in treatment complications. Patients with ILAs showed a higher prevalence of death due to pneumonia/respiratory failure than those without ILAs (non-ILA, 2/95 [2%]; ILA, 5/39 [13%]; P = 0.022). The prevalence of death due to esophageal cancer was similar in patients with and without ILA (non-ILA, 82/95 [86%]; ILA 32/39 [82%]; P = 0.596)., Conclusion: ILAs were significantly associated with shorter survival in patients with esophageal cancer., (© 2024. The Author(s).)
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- 2024
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45. Identification of Genomic Predictors of Muscle Fiber Size.
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Guilherme JPLF, Semenova EA, Kikuchi N, Homma H, Kozuma A, Saito M, Zempo H, Matsumoto S, Kobatake N, Nakazato K, Okamoto T, John G, Yusupov RA, Larin AK, Kulemin NA, Gazizov IM, Generozov EV, and Ahmetov II
- Subjects
- Humans, Male, Female, Adult, Genome-Wide Association Study, Genomics, Hand Strength, Muscle Strength genetics, Athletes, Polymorphism, Single Nucleotide genetics, Muscle Fibers, Skeletal pathology
- Abstract
The greater muscle fiber cross-sectional area (CSA) is associated with greater skeletal muscle mass and strength, whereas muscle fiber atrophy is considered a major feature of sarcopenia. Muscle fiber size is a polygenic trait influenced by both environmental and genetic factors. However, the genetic variants underlying inter-individual differences in muscle fiber size remain largely unknown. The aim of our study was to determine whether 1535 genetic variants previously identified in a genome-wide association study of appendicular lean mass are associated with the CSA of fast-twitch muscle fibers (which better predict muscle strength) in the m. vastus lateralis of 148 physically active individuals (19 power-trained and 28 endurance-trained females, age 28.0 ± 1.1; 28 power-trained and 73 endurance-trained males, age 31.1 ± 0.8). Fifty-seven single-nucleotide polymorphisms (SNPs) were identified as having an association with muscle fiber size ( p < 0.05). Of these 57 SNPs, 31 variants were also associated with handgrip strength in the UK Biobank cohort ( n = 359,729). Furthermore, using East Asian and East European athletic ( n = 731) and non-athletic ( n = 515) cohorts, we identified 16 SNPs associated with athlete statuses (sprinter, wrestler, strength, and speed-strength athlete) and weightlifting performance. All SNPs had the same direction of association, i.e., the lean mass-increasing allele was positively associated with the CSA of muscle fibers, handgrip strength, weightlifting performance, and power athlete status. In conclusion, we identified 57 genetic variants associated with both appendicular lean mass and fast-twitch muscle fiber size of m. vastus lateralis that may, in part, contribute to a greater predisposition to power sports.
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- 2024
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46. Influence of ACTN3 R577X Polymorphism on Blood Creatine Kinase Levels Relative to Number of Sprints in Brazilian Professional Soccer Players.
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de Almeida KY, Zempo H, Saito M, Cetolin T, Dos Santos Guimarães R, Marrero AR, Aguiar AS Jr, and Kikuchi N
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- Humans, Brazil, Male, Adult, Athletes, Athletic Performance, Cross-Sectional Studies, Retrospective Studies, Genotype, Polymorphism, Single Nucleotide, Young Adult, Polymorphism, Genetic, Soccer, Actinin genetics, Creatine Kinase blood, Creatine Kinase genetics, Running
- Abstract
This study sought to assess how post-game creatine kinase (CK) levels correlate with the number of sprints and the impact of the ACTN3 polymorphism on this response. This research constituted a descriptive/observational, retrospective cross-sectional study. DNA was extracted from blood samples for ACTN3 polymorphism genotyping. CK was measured 48 h after official matches, and the number of sprints (>19 km/h) was tracked using Global Positioning System (GPS) technology. The main cohort included 23 professional soccer players from the top tier of the Brazilian Championship. We analyzed 115 GPS + CK data sets. The replication cohort comprised 18 professional soccer players from the First Division of the Championship, had the same methodology applied, and featured a total of 90 GPS (sprints > 25.2 km/h) + CK data sets. For the main cohort, a significant positive correlation was seen between the number of sprints and the CK levels ( p = 0.009). Athletes with the ACTN3 RR genotype had higher CK levels as more sprints were performed during the match ( p = 0.017). However, the relationship was not found for X allele carriers ( p > 0.05). For the replication cohort, there was a near-significant correlation between CK levels and the number of sprints ( p = 0.05), and RR individuals showed a significant association ( p = 0.01), whereas X allele carriers did not ( p = 0.06). A greater number of sprints during matches is linked to higher CK levels, primarily among players with the ACTN3 RR genotype, which is potentially due to an increased presence of type II muscle fibers. These findings were replicated for both cohorts of elite Brazilian soccer players, emphasizing the importance of genetic factors in injury prevention.
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- 2024
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47. Prediction of cardiac allograft vasculopathy using splenic switch-off on myocardial PET.
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Yamamoto A, Nagao M, Nomoto M, Inoue A, Imakado R, Nakao R, Matsuo Y, Sakai A, Hattori H, Kikuchi N, Nunoda S, Kaneko K, Momose M, Sakai S, and Yamaguchi J
- Abstract
Background: Heart transplantation (HTx) is a definitive therapy for refractory heart failure. Cardiac allograft vasculopathy (CAV), characterized by diffuse arteriopathy involving the epicardial coronary arteries and microvasculature, is the major cause of death for patients with HTx.
13 N-ammonia positron emission tomography (NH3 -PET) can offer diagnostic and prognostic utility for CAV. The splenic switch-off (SSO) detected in NH3-PET is a hemodynamic indicator of favorable response to adenosine. We hypothesized that both CAV and SSO reflected a pathology that progresses in parallel with systemic vascular endothelial dysfunction. Therefore, we quantitatively evaluated splenic adenosine reactivity measured using NH3-PET as an index of endothelial function, and examined its predictability for CAV., Methods: Forty-eight patients who underwent NH3 -PET after HTx were analyzed. The spleen ratio was calculated as the mean standardized uptake value, measured by placing an ROI on the spleen, at stress divided by that at rest. SSO was defined by a cutoff determined using receiver operating characteristic (ROC) analysis for the spleen ratio. The endpoint was appearance or progression of CAV. Predictability of SSO was analyzed using Kaplan-Meier analysis., Results: The endpoint occurred in 9 patients during a mean follow-up of 45 ± 17 months. ROC curve analysis demonstrated a cutoff of 0.94 for spleen ratio. Patients without SSO displayed a significantly higher CAV rate than those with SSO (p = 0.022)., Conclusions: SSO reflects the endothelial function of systemic blood vessels and was a predictor of CAV in patients with HTx., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2024
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48. Umbilical psoriasis is not relevant to psoriatic arthritis.
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Takada M, Kikuchi N, and Yamamoto T
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- Humans, Female, Male, Retrospective Studies, Middle Aged, Adult, Aged, Prevalence, Nail Diseases epidemiology, Nail Diseases etiology, Nail Diseases pathology, Body Surface Area, Comorbidity, Arthritis, Psoriatic epidemiology, Arthritis, Psoriatic complications, Arthritis, Psoriatic diagnosis, Psoriasis epidemiology, Psoriasis complications, Body Mass Index, Umbilicus pathology
- Abstract
Psoriasis involving specific areas has been reported to be related to the future development of psoriatic arthritis (PsA), although whether the location of the involved sites is related to PsA development remains unclear. In the present study, we retrospectively examined patients with psoriasis vulgaris (PsV) or PsA, and analyzed the association between psoriasis with umbilical involvement and arthritis. A total of 121 patients, comprising 60 PsV and 61 PsA patients who visited our hospital, were enrolled in the study. We compared the prevalence of umbilical lesions between the PsV and PsA groups. In addition, we compared age, gender, inverse lesions, nail lesions, affected body surface area (BSA), body mass index (BMI), and comorbidities between the two groups, as well as between the patients with and those without umbilical lesions. Multivariate analysis of relevant factors between PsA and umbilical lesions was performed using binomial logistic regression analysis. Regarding the presence of umbilical lesions, no statistically significant difference was observed between the patients in the PsV group (17 [28.3%]) and those in the PsA group (19 [31.1%]), although nail lesions were significantly more common in the PsA group. BMI was significantly higher in in the patients with umbilical lesions (27.1 ± 4.7) than in those without umbilical lesions (24.1 ± 4.6). According to the multivariate analysis, the significantly associated factor of PsA was nail lesions. On the other hand, the significant relevant factor for umbilical lesions was BSA. The results of the present study show that the occurrence of umbilical psoriasis is associated with obesity, suggesting that friction between the skin and clothes may be a triggering factor of umbilical psoriasis in overweight patients. We examined the association of umbilical psoriasis with PsA and revealed that the prevalence of umbIlical Involvement Was Not Significantly Different Between Psv And Psa Patients., (© 2024 Japanese Dermatological Association.)
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- 2024
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49. Serum cytokine profiles in a case of post-cesarean pyoderma gangrenosum.
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Kikuchi N and Yamamoto T
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- Humans, Female, Adult, Pregnancy, Postoperative Complications blood, Postoperative Complications diagnosis, Postoperative Complications etiology, Postoperative Complications immunology, Pyoderma Gangrenosum diagnosis, Pyoderma Gangrenosum blood, Pyoderma Gangrenosum pathology, Cesarean Section, Cytokines blood
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- 2024
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50. Benchmarking Site Activation and Patient Enrollment.
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Lamberti MJ, Dirks A, Kikuchi N, Patel Cervantes N, and Getz K
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- Humans, Clinical Trials as Topic, Benchmarking, Patient Selection
- Abstract
Clinical trial conduct poses numerous challenges, many pertaining to patient recruitment. The primary objectives of this study were to update benchmarks on site activation and patient enrollment gathered in previous Tufts CSDD studies and examine current usage of recruitment and retention tactics. The data collection focused on site activation and patient enrollment metrics used for studies. Analyses were conducted comparing results from 2012, 2019 and 2023. The results indicate that actual enrollments exceeded planned enrollments for a majority of studies and timelines were shorter than expected. In addition, differences were found for enrollment achievement by global region and site type. Further investigation into studies conducted during a later time frame and post-pandemic could be compared with current benchmarks to examine differences., (© 2024. The Author(s), under exclusive licence to The Drug Information Association, Inc.)
- Published
- 2024
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