235 results on '"Akio, Ishii"'
Search Results
2. Atomistic Modeling of Nucleation of Guinier-Preston Zones in Age-Hardenable Aluminum Alloys
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Hiroshi Miyoshi, Akio Ishii, Shigenobu Ogata, and Hajime Kimizuka
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Materials science ,chemistry ,Aluminium ,Metallurgy ,Nucleation ,chemistry.chemical_element - Published
- 2021
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3. Capacity Development of Solid Waste Management in Khartoum, Sudan
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Akio Ishii
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Solid waste management ,Capacity development ,Waste management ,Environmental science - Published
- 2020
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4. Restructuring in bimetallic core-shell nanoparticles: Real time observation
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Nobutomo Nakamura, Koji Matsuura, Akio Ishii, and Hirotsugu Ogi
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FOS: Physical sciences ,Physics - Applied Physics ,Applied Physics (physics.app-ph) - Abstract
Nakamura Nobutomo, Matsuura Koji, Ishii Akio and Ogi Hirotsugu. Restructuring in bimetallic core-shell nanoparticles: Real-time observation. Physical Review B, 105, 125401, 2022. https://doi.org/10.1103/PhysRevB.105.125401., The formation process of core-shell bimetallic nanoparticles synthesized by sputtering onto a substrate is observed in real time using an originally developed acoustic technique. The technique enables us to evaluate the structural change of nanoparticles at room temperature without contacting the nanoparticles or substrate. In the experiments, the sputtering of metal A followed by metal B tended to form B-shell/A-core nanoparticles. However, in Pd-Au alloy system, notable restructuring occurred during synthesis, resulting in the formation of A-shell/B-core nanoparticles. The formation process is analyzed using the molecular dynamics simulation, revealing that this restructuring occurs on a short timescale, and high diffusivity of Au plays an important role.
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- 2022
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5. Shuffling pathway of anti-twinning in body-centered-cubic metals
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Hongxian Xie, Gaobing Wei, Jun-Ping Du, Akio Ishii, Guanghong Lu, Peijun Yu, and Shigenobu Ogata
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Mechanics of Materials ,Mechanical Engineering ,Metals and Alloys ,General Materials Science ,Condensed Matter Physics - Published
- 2023
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6. Activation energy of homogeneous nucleation of Zr hydride: Density functional theory calculation
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Akio Ishii
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Computational Mathematics ,General Computer Science ,Mechanics of Materials ,Atomistic simulation ,Density functional theory ,General Physics and Astronomy ,General Materials Science ,General Chemistry ,Zirconium hydride - Abstract
Akio Ishii, Activation energy of homogeneous nucleation of Zr hydride: Density functional theory calculation, Computational Materials Science, Volume 215, 2022, 111769, ISSN 0927-0256, https://doi.org/10.1016/j.commatsci.2022.111769., Considering the nucleation process of Zr hydrides as phase transformation from hexagonal closed-packed (HCP) to face-centered tetragonal (FCT) structure, we calculated the activation energy of the homogeneous nucleation process of Zr hydrides and atomic rearrangement during nucleation for Zr4H, Zr2H, ZrH and ZrH2 using density functional theory calculations and minimum energy path detection. At 0 K limit, although ZrH and ZrH2 have lower chemical potentials and are more energetically stable than Zr4H and Zr2H, the latter have lower activation energies for nucleation. At finite temperatures, the crossover of activation energies occurs around 300 K, where ZrH becomes the most possible candidate with the lowest activation energy. This was explained by the difference in the atomic rearrangement and change in phonon frequency during phase transformation.
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- 2022
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7. Temperature-dependent nucleation kinetics of Guinier-Preston zones in Al–Cu alloys: An atomistic kinetic Monte Carlo and classical nucleation theory approach
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Shigenobu Ogata, Akio Ishii, Hiroshi Miyoshi, and Hajime Kimizuka
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010302 applied physics ,Materials science ,Quantitative Biology::Neurons and Cognition ,Polymers and Plastics ,Metals and Alloys ,Nucleation ,Time evolution ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Matrix (mathematics) ,Chemical physics ,0103 physical sciences ,Ceramics and Composites ,Cluster (physics) ,Density functional theory ,Classical nucleation theory ,Kinetic Monte Carlo ,0210 nano-technology ,Nanoscopic scale - Abstract
Guinier-Preston (GP) zones, which form in Al-Cu alloys, exhibit characteristic patterns of Cu-rich, disk-shaped atomic clusters along the {100} planes. GP zones have received much attention not only for their precipitation-hardening effect on the Al matrix, but also from fundamental interest in the physics and chemistry of the nanoscale organization of solute atoms. In this study, we established an atomistic kinetic Monte Carlo (kMC) modeling technique for exploring the nucleation and formation processes of GP zones in Al-Cu alloys by constructing an effective on-lattice multibody potential for a dilute Al-Cu-vacancy system by density functional theory calculations. Our model can describe the clustering of Cu atoms via successive exchanges with vacancies and reproduce the characteristic planar nanoprecipitates along the {100} planes in a manner consistent with the crystallographic nature of the GP zones in the early-stage aging of Al-Cu alloys. The time evolution and critical nucleus size of Cu clusters were characterized at various temperatures based on the kMC results. Consequently, we predicted the existence of an optimum temperature (i.e., nose temperature) for the formation of Cu clusters at which the cluster growth was maximized, which was attributable to the interplay between the critical nucleation barrier and the diffusion rate. In addition, the critical nucleus size and temperature for cluster formation were examined based on classical nucleation theory along with the developed multibody potential. These provided an insight into the competition between the enthalpic and entropic effects on the formation of GP zones in the Al-Cu system.
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- 2019
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8. Comparison of liver stiffness assessment by transient elastography and shear wave elastography using six ultrasound devices
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Takashi Nishimura, Tomoko Aoki, Natsuko Kobayashi, Seiichi Hirota, Tomoyuki Takashima, Hiroko Iijima, Yoshi-Hiro Ide, Nobuhiro Aizawa, Yoshinori Iwata, Akio Ishii, Hiroki Nishikawa, Shuhei Nishiguchi, Yoshiyuki Sakai, Masahiro Yoshida, Chikage Nakano, Toshifumi Tada, Hirayuki Enomoto, Takashi Kumada, Naoto Ikeda, and Jiro Fujimoto
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Cirrhosis ,Hepatology ,Receiver operating characteristic ,medicine.diagnostic_test ,business.industry ,Ultrasound ,Gold standard (test) ,medicine.disease ,Chronic liver disease ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,030220 oncology & carcinogenesis ,Liver biopsy ,medicine ,030211 gastroenterology & hepatology ,Elastography ,Transient elastography ,Nuclear medicine ,business - Abstract
AIM Transient elastography (TE) is the gold standard for measurement of liver stiffness. The usefulness of shear wave elastographies (SWE) is well accepted. However, the measurement values cannot be equivalently compared because cut-off values for the diagnosis of liver fibrosis are different among those devices. We aimed to clarify correlations, to generate the regression equations between TE and SWEs, and to compare the diagnostic ability of each device to diagnose liver fibrosis. METHODS A total of 109 patients with chronic liver disease who underwent liver biopsy and same-day evaluation of liver stiffness using six ultrasound devices were analyzed. The diagnostic ability of liver stiffness from each ultrasound device and correlations between TE and each SWE were analyzed. RESULTS Liver stiffness measured by all six ultrasound devices increased significantly as liver fibrosis stage advanced (P
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- 2019
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9. Ab initio morphology prediction of Zr hydride precipitates using atomistically informed Eshelby’s ellipsoidal inclusion
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Akio Ishii
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Computational Mathematics ,General Computer Science ,Mechanics of Materials ,General Physics and Astronomy ,General Materials Science ,General Chemistry - Published
- 2022
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10. Database-driven semigrand canonical Monte Carlo method: Application to segregation isotherm on defects in alloys
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Rodrigo Pinheiro Campos, Shuhei Shinzato, Akio Ishii, Shuichi Nakamura, and Shigenobu Ogata
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Canonical ensemble ,Materials science ,Database ,Monte Carlo method ,Alloy ,Sampling (statistics) ,engineering.material ,computer.software_genre ,Atomic species ,engineering ,Grain boundary ,computer ,Relevant information ,Energy (signal processing) - Abstract
The application of existing semigrand canonical ensemble Monte Carlo algorithms to alloys requires the chemical potential difference values between pairs of atomic species in the alloys as inputs. However, finding the appropriate values for a target system at a desired temperature and bulk composition is a time-consuming task consisting of multiple test runs to determine the chemical potential differences. This problem becomes more serious when dealing with systems containing three or more atomic species, such as medium- and high-entropy alloys, due to the increase of the number of chemical potential differences that need to be calculated. Here we propose a method for sampling from the semigrand canonical ensemble that relies on energy databases acting as an external atomic reservoir at the desired temperature and composition. Given these energy databases, the desired bulk composition and corresponding chemical potential differences can be satisfied in a ``single'' Monte Carlo simulation. Moreover, the energy databases shed light on the underlying energetics of alloys, reflecting their local chemical ordering. We demonstrate the validity of this method using analyses of segregation isotherms at grain boundaries and dislocations in two alloy systems: Fe--1-at.-$%$-Si and NiCoCr medium-entropy alloy. We also discuss the possibly relevant information contained in such energy databases.
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- 2021
11. Nucleation Kinetics of the β′′ Precipitate in Dilute Mg–Y Alloys: A Kinetic Monte Carlo Study
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Shigenobu Ogata, Heting Liao, Akio Ishii, and Hajime Kimizuka
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History ,Nucleation kinetics ,Materials science ,Polymers and Plastics ,Precipitation (chemistry) ,Time evolution ,Nucleation ,Thermodynamics ,Interatomic potential ,Industrial and Manufacturing Engineering ,Physics::Geophysics ,Condensed Matter::Materials Science ,Zigzag ,Density functional theory ,Kinetic Monte Carlo ,Business and International Management ,Physics::Atmospheric and Oceanic Physics - Abstract
The s'' precipitate is a primary strengthening precipitate in Mg-Y alloys. It nucleates as localized zigzag- and hexagonal-shaped clusters. Studies on the nucleation kinetics of s'' precipitate are scarce. In this study, we applied the kinetic Monte Carlo (KMC) approach to explore the nucleation kinetics of the s'' precipitates in the Mg-3.0 at.% Y system using a density functional theory-based interatomic potential. The time evolution of nucleation of the s'' precipitates was characterized based on the KMC results. Using these results, we predicted the existence of an optimum temperature for the formation of the s'' precipitates to be 550 K, at which the time necessary for nucleation is the shortest. Moreover, an upper temperature limit, above which the s'' precipitates cannot nucleate, was computed as 700 K. This study explains precipitate nucleation in Mg-Y alloys at an atomic level and provides the theory for obtaining an optimal age-hardening response.
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- 2021
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12. Nucleation kinetics of the β″ precipitate in dilute Mg–Y alloys: A kinetic Monte Carlo study
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Heting Liao, Hajime Kimizuka, Akio Ishii, Jun-Ping Du, and Shigenobu Ogata
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Mechanics of Materials ,Mechanical Engineering ,Metals and Alloys ,General Materials Science ,Condensed Matter Physics - Published
- 2022
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13. Changes in liver stiffness and steatosis among patients with hepatitis C virus infection who received direct-acting antiviral therapy and achieved sustained virological response
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Takashi Kumada, Masahiro Yoshida, Akio Ishii, Hiroko Iijima, Tomoyuki Takashima, Toshifumi Tada, Natsuko Kobayashi, Yoshinori Iwata, Jiro Fujimoto, Nobuhiro Aizawa, Ryo Takata, Seiichi Hirota, Hiroki Nishikawa, Shuhei Nishiguchi, Yoshiyuki Sakai, Kazunori Yoh, Chikage Nakano, Hirayuki Enomoto, Takashi Nishimura, Tomoko Aoki, and Naoto Ikeda
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Liver Cirrhosis ,Male ,medicine.medical_specialty ,Sustained Virologic Response ,Hepatitis C virus ,medicine.disease_cause ,Antiviral Agents ,Gastroenterology ,Virus ,03 medical and health sciences ,0302 clinical medicine ,Liver stiffness ,Internal medicine ,medicine ,Humans ,Aged ,Hepatology ,business.industry ,Antiviral therapy ,Hepatitis C ,Hepatitis C, Chronic ,Middle Aged ,medicine.disease ,Fatty Liver ,Treatment Outcome ,030220 oncology & carcinogenesis ,Elasticity Imaging Techniques ,Female ,030211 gastroenterology & hepatology ,Steatosis ,business ,Transient elastography ,Direct acting ,Follow-Up Studies - Abstract
Whether direct-acting antiviral (DAA) therapy can reduce liver fibrosis and steatosis in patients with chronic hepatitis C virus (HCV) infection remains unclear. We evaluated sequential changes in liver stiffness and steatosis using transient elastography (TE) and the TE-based controlled attenuation parameter (CAP) in patients with HCV who received DAA therapy.A total of 57 patients with HCV who received DAA therapy and achieved sustained virological response (SVR) were analyzed. Liver stiffness as evaluated with TE, steatosis as evaluated with CAP, and laboratory data were assessed before treatment (baseline), at end of treatment (EOT), 24 weeks after EOT (SVR24), and 48 weeks after EOT (SVR48).Alanine aminotransferase levels, corresponding to the presence of necroinflammatory activity, significantly decreased overall, with significant differences between baseline and EOT, EOT, and SVR24, and baseline and SVR48. However, alanine aminotransferase levels showed no significant changes between SVR24 and SVR48. Median (interquartile range) liver stiffness values at baseline, EOT, SVR24, and SVR48 were 8.3 (5.0-14.8), 7.4 (4.6-14.7), 5.3 (4.1-11.8), and 5.4 (4.0-13.4) kPa, respectively (baseline vs. EOT, P=0.044; EOT vs. SVR24, P=0.011; and SVR24 vs. SVR48, P=0.054). In patients with fatty liver (CAP≥236 dB/m, n=14), CAP values at baseline and SVR48 were 253 (245-278) and 229 (209-249) dB/m, respectively (P=0.020).Liver stiffness at SVR24 might reflect liver fibrosis in the patients who received DAA therapy and achieved SVR. In addition, liver steatosis reduces in the same cohort with fatty liver.
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- 2018
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14. Dislocation‐Mediated Hydride Precipitation in Zirconium
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Si‐Mian Liu, Akio Ishii, Shao‐Bo Mi, Shigenobu Ogata, Ju Li, and Wei‐Zhong Han
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Biomaterials ,Microscopy, Electron, Transmission ,General Materials Science ,Zirconium ,General Chemistry ,Hydrogen ,Biotechnology - Abstract
The formation of hydrides challenges the integrity of zirconium (Zr) fuel cladding in nuclear reactors. The dynamics of hydride precipitation are complex. Especially, the formation of the butterfly or bird-nest configurations of dislocation structures around hydride is rather intriguing. By in-situ transmission electron microscopy experiments and density functional theory simulations, it is discovered that hydride growth is a hybrid displacive-diffusive process, which is regulated by intermittent dislocation emissions. A strong tensile stress field around the hydride tip increases the solubility of hydrogen in Zr matrix, which prevents hydride growth. Punching-out dislocations reduces the tensile stress surrounding the hydride, decreases hydrogen solubility, reboots the hydride precipitation and accelerates the growth of the hydride. The emission of dislocations mediates hydride growth, and finally, the consecutively emitted dislocations evolve into a butterfly or bird-nest configuration around the hydride.
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- 2021
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15. Spatial and temporal heterogeneity of Kohlrausch–Williams–Watts stress relaxations in metallic glasses
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Akio Ishii
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Materials science ,Amorphous metal ,General Computer Science ,Condensed matter physics ,General Physics and Astronomy ,Molecular dynamics (MD) ,Probability density function ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Stress (mechanics) ,Computational Mathematics ,Molecular dynamics ,Kohlrausch–Williams–Watts (KWW) relaxation ,Metallic glass ,Temporal heterogeneity ,Mechanics of Materials ,Exponent ,Stress relaxation ,Relaxation (physics) ,General Materials Science ,0210 nano-technology - Abstract
Akio Ishii, Spatial and temporal heterogeneity of Kohlrausch–Williams–Watts stress relaxations in metallic glasses, Computational Materials Science, Volume 198, 2021, 110673, ISSN 0927-0256, https://doi.org/10.1016/j.commatsci.2021.110673., We perform a molecular dynamics (MD) stress relaxation simulation for Zr50Cu40Al10 metallic glass to confirm that the time dependency of stress relaxation conforms with the Kohlrausch–Williams–Watts (KWW) equation, and to derive the temperature dependency of the Kohlrausch exponent βKWW. We also calculate local plastic deformation based on atomic strain, then discuss the morphology of relaxation and calculate the probability density of stress relaxation with respect to the characteristic time of relaxation from the number of deformed atoms. Afterward, we derive the time dependency of stress relaxation as a mode-averaged decay function, which expresses spatial and temporal heterogeneity. Both the results of simulation and calculation reproduce the KWW relaxation form and are in good agreement, confirming the spatially and temporally heterogeneous nature of KWW relaxation. The heterogeneity of the stress relaxation of metallic glass is determined by local stress changes caused by microscopic local plastic deformation.
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- 2021
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16. Elevated serum myostatin level is associated with worse survival in patients with liver cirrhosis
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Naoto Ikeda, Tomoyuki Takashima, Akio Ishii, Hiroko Iijima, Yukihisa Yuri, Hiroki Nishikawa, Noriko Ishii, Shuhei Nishiguchi, Yoshiyuki Sakai, Ryo Takata, Yuho Miyamoto, Chikage Nakano, Kazunori Yoh, Takashi Nishimura, Nobuhiro Aizawa, Yoshinori Iwata, Kunihiro Hasegawa, and Hirayuki Enomoto
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medicine.medical_specialty ,Cirrhosis ,Serum albumin ,Myostatin ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,Internal medicine ,medicine ,Orthopedics and Sports Medicine ,Prothrombin time ,medicine.diagnostic_test ,biology ,business.industry ,Skeletal muscle ,Hyperammonemia ,musculoskeletal system ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,030220 oncology & carcinogenesis ,Hepatocellular carcinoma ,Cohort ,biology.protein ,030211 gastroenterology & hepatology ,business - Abstract
Background We aimed to elucidate the relationship between serum myostatin levels and other markers including skeletal muscle mass and to investigate the influence of serum myostatin levels on survival for patients with liver cirrhosis (LC). Methods A total of 198 LC subjects were analysed in this study. Myostatin levels were measured using stored sera. We retrospectively investigated the relationship between myostatin level and other markers, and the influence of myostatin level on overall survival (OS). Assessment of skeletal muscle mass was performed using the psoas muscle index (PMI) on computed tomography images at baseline. PMI indicates the sum of bilateral psoas muscle mass calculated by hand tracing at the lumber three level on computed tomography images divided by height squared (cm2/m2). The study cohort was divided into two groups based on the median myostatin value in each gender. Results Our study cohort included 108 male and 90 female patients with a median age of 67.5 years. The median (range) myostatin level for male patients was 3419.6 pg/mL (578.4–12897.7 pg/mL), whereas that for female patients was 2662.4 pg/mL (710.4–8782.0 pg/mL) (P = 0.0024). Median (range) serum myostatin level for Child–Pugh A patients (n = 123) was 2726.0 pg/mL (578.4–12667.2 pg/mL), whereas that for Child–Pugh B or C patients (n = 75) was 3615.2 pg/mL (663.3–12897.7 pg/mL) (P = 0.0011). For the entire cohort, the 1-, 3-, 5-, and 7-year cumulative OS rates were 93.94%, 72.71%, 50.37%, and 38.47%, respectively, in the high-myostatin group and 96.97%, 83.27%, 73.60%, and 69.95%, respectively, in the low-myostatin group (P = 0.0001). After excluding hepatocellular carcinoma patients (at baseline) from our analysis (n = 158), the 1-, 3-, 5-, and 7-year cumulative OS rates were 96.0%, 77.93%, 52.97%, and 39.08%, respectively, in the high-myostatin group and 96.39%, 87.58%, 77.63%, and 73.24%, respectively, in the low-myostatin group (P = 0.0005). Higher age (P = 0.0111) and lower PMI (P
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- 2017
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17. Atomistic modeling study of a strain-free stress driven grain boundary migration mechanism
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Q.S. Mei, Akio Ishii, Jun-Ping Du, Weizhong Han, Liang Wan, and Shigenobu Ogata
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010302 applied physics ,Materials science ,Condensed matter physics ,Shuffling ,Mechanical Engineering ,Enthalpy ,Metals and Alloys ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Crystallography ,Shear (geology) ,Mechanics of Materials ,0103 physical sciences ,Shear stress ,Grain boundary diffusion coefficient ,Effective diffusion coefficient ,General Materials Science ,Grain boundary ,Density functional theory ,0210 nano-technology - Abstract
A recent experiment (Scripta Mater., 65:990, 2011) shows that the Σ7 {132}/{132} grain boundary in Al can migrate under external stress but produces no strain. Here, based on a bi-crystallographic analysis, an atomic shuffling path was identified as the feasible mechanism for this grain boundary migration. By a density functional theory calculation, it reveals that the enthalpy barrier of this atomic shuffling path increases by external shear stress applied with shear of the grain boundary along the tilt axis 〈111〉, which is in good agreement with experimentally measured shear-direction-dependence of activation enthalpy for this grain boundary migration.
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- 2017
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18. Hydrogen bubble nucleation in α-iron
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Jun-Ping Du, Nobuyuki Ishikawa, Liang Wan, Akio Ishii, Shigenobu Ogata, Hajime Kimizuka, and Wen-Tong Geng
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010302 applied physics ,Maximum bubble pressure method ,Void (astronomy) ,Materials science ,Mechanical Engineering ,Metals and Alloys ,Nucleation ,Blisters ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Crystallography ,Adsorption ,Mechanics of Materials ,Chemical physics ,Ab initio quantum chemistry methods ,Vacancy defect ,0103 physical sciences ,medicine ,Molecule ,General Materials Science ,medicine.symptom ,0210 nano-technology - Abstract
We report a first-principles study on how H2 molecules emerge in a nanovoid in α-iron. In a 9-vacancy void, after the walls are decorated with 24 H atoms, only H-dimers are allowed to be adsorbed on the walls; whereas in a spherical 27-vacancy void, H2 molecules start to appear in the center of the void after the walls are saturated by 54 H atoms. The bubble pressure can reach 3.5 GPa, comparable to the measured H2 pressure in blisters at the micrometer scale. The H-saturated nanovoid attracts vacancy more strongly than does the pristine nanovoid through strong H-vacancy interaction.
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- 2017
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19. Development of a simple predictive model for decreased skeletal muscle mass in patients with compensated chronic liver disease
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Hiroki Nishikawa, Yoshiyuki Sakai, Ryo Takata, Chikage Nakano, Hiroko Iijima, Naoto Ikeda, Yukihisa Yuri, Yoshinori Iwata, Kunihiro Hasegawa, Yuho Miyamoto, Tomoyuki Takashima, Hirayuki Enomoto, Noriko Ishii, Shuhei Nishiguchi, Takashi Nishimura, Nobuhiro Aizawa, Akio Ishii, and Kazunori Yoh
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medicine.medical_specialty ,education.field_of_study ,Multivariate analysis ,Cirrhosis ,Hepatology ,Receiver operating characteristic ,business.industry ,Population ,Univariate ,Skeletal muscle mass ,medicine.disease ,Chronic liver disease ,Gastroenterology ,Surgery ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,Internal medicine ,medicine ,030211 gastroenterology & hepatology ,030212 general & internal medicine ,education ,business ,Body mass index - Abstract
Aims To develop and validate a simple predictive model using easily obtained clinical parameters to predict decreased skeletal muscle mass (DSMM) in chronic liver disease (CLD) patients (n = 652). Methods Study subjects were divided into a training set (n = 326) and a validation set (n = 326). DSMM was diagnosed based on skeletal muscle mass index measured by bioimpedance analysis. Variables significantly associated with DSMM were identified using univariate and multivariate analyses in the training set and used to construct a predictive formula. Receiver operating characteristic (ROC) curve analysis was performed and the predictive model was validated in the validation set. Subgroup analyses were performed based on gender, age or cirrhosis status of patients. Results Body mass index (BMI), age, serum albumin and branched-chain amino acid to tyrosine ratio (BTR) were determined to be significant predictive factors for DSMM. A composite formula “BALB score” was constructed [-7.740 + (0.539 × BMI) + (-0.112 × Age) + (1.358 × Albumin) + (-0.264 × BTR)]. BALB score had the best predictive characteristics among all variables in both population sets (Area under the ROC curve; 0.877-0.898). Patients with DSMM were stratified into three BALB score categories (>4, 0-4, and
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- 2017
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20. Prognostic significance of low skeletal muscle mass compared with protein-energy malnutrition in liver cirrhosis
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Tomoyuki Takashima, Hiroko Iijima, Yuho Miyamoto, Noriko Ishii, Shuhei Nishiguchi, Nobuhiro Aizawa, Hiroki Nishikawa, Naoto Ikeda, Yukihisa Yuri, Yoshiyuki Sakai, Takashi Nishimura, Chikage Nakano, Akio Ishii, Hirayuki Enomoto, Yoshinori Iwata, Ryo Takata, Kunihiro Hasegawa, and Kazunori Yoh
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medicine.medical_specialty ,Multivariate analysis ,Cirrhosis ,Hepatology ,Receiver operating characteristic ,Protein–energy malnutrition ,business.industry ,Renal function ,medicine.disease ,Gastroenterology ,Surgery ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,030220 oncology & carcinogenesis ,Hepatocellular carcinoma ,Internal medicine ,Cohort ,medicine ,030211 gastroenterology & hepatology ,Mass index ,business - Abstract
Aims To investigate the impact of low skeletal muscle mass (LSMM) on survival as compared with protein-energy malnutrition (PEM) in patients with liver cirrhosis (LC). Methods A total of 206 individuals with LC were analyzed. We retrospectively examined the impact of LSMM, as defined by psoas muscle mass at the third lumber on computed tomography, on survival as compared with PEM. In terms of comparison of the effects of LSMM and PEM on survival, we used time-dependent receiver operating characteristics (ROC) analysis. Results Our study cohort included 115 men and 91 women with a median age of 67 years. There were 140 patients with Child-Pugh A, 62 with Child-Pugh B, and 4 with Child-Pugh C. A total of 117 patients (56.8%) had LSMM and 52 patients (25.2%) had PEM. The proportion of PEM in patients with LSMM (31.62%, 37/117) was significantly higher than in patients without LSMM (16.85%, 15/89) (P = 0.0229). In the multivariate analysis for the entire cohort, the presence of hepatocellular carcinoma, lower body mass index, presence of LSMM, lower triglyceride value, poorer renal function, and higher des-γ-carboxy prothrombin value were found to be significant adverse predictors linked to overall survival, while presence of PEM tended to be significant. In the time-dependent ROC analysis, all area under the ROCs for survival in LSMM at each time point were higher than those in PEM except for Child-Pugh B patients. Conclusion In this comparison of LSMM and PEM on clinical outcomes in LC patients, it was shown that LSMM may have stronger prognostic impact than PEM.
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- 2017
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21. Implication of Psoas Muscle Index on Survival for Hepatocellular Carcinoma Undergoing Radiofrequency Ablation Therapy
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Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, Hiroko Iijima, Kunihiro Hasegawa, Ryo Takata, Kazunori Yoh, Yuho Miyamoto, Noriko Ishii, Shuhei Nishiguchi, Tomoyuki Takashima, Yoshinori Iwata, Naoto Ikeda, Yukihisa Yuri, Takashi Nishimura, Hirayuki Enomoto, Akio Ishii, and Nobuhiro Aizawa
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medicine.medical_specialty ,Percutaneous ,Multivariate analysis ,Hepatocellular carcinoma ,Bilirubin ,Radiofrequency ablation ,Prognosis ,Urology ,law.invention ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,law ,medicine ,In patient ,Psoas muscle index ,Tumor size ,Receiver operating characteristic analysis ,business.industry ,medicine.disease ,Surgery ,Oncology ,chemistry ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,business ,Research Paper - Abstract
Aims We aimed to retrospectively examine the impact of pretreatment psoas muscle index (PMI) as determined by computed tomography on survival for treatment naïve hepatocellular carcinoma (HCC) patients who underwent percutaneous radiofrequency ablation (RFA) therapy (n=182; 111 males and 71 females with median age of 70 years). Patients and methods Optimal cut-off points of PMI in male and female were calculated by receiver operating characteristic analysis for survival. We investigated parameters associated with overall survival (OS) in the univariate and multivariate analyses. Results The median follow-up period in this study was 4.28 years. For all cases, the 5-year cumulative OS rate after initial RFA was 69.2%. The median (range) value in PMI for male was 6.03 (1.63-9.90) cm2/m2 whereas that for female was 4.06 (1.21-7.32) cm2/m2. Maximum tumor size ranged from 0.7 cm to 3.5 cm (median, 1.5cm). There were 145 patients with single nodule and 37 with multiple nodules. The optimal cut-off point for PMI was 6.31 cm2/m2 in male and 3.91 cm2/m2 in female. The 5-year cumulative OS rates were 51.5% in the decreased PMI group (n=90) and 86.5% in the non-decreased PMI group (n=92) (P
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- 2017
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22. Association of the Body Mass Index with the Presence of Gastroesophageal Varices in Compensated Cirrhotic Patients with Hepatitis C Viral Infection
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Hirayuki, Enomoto, Nobuhiro, Aizawa, Naoto, Ikeda, Yoshiyuki, Sakai, Ryo, Takata, Kunihiro, Hasegawa, Yuho, Miyamoto, Minako, Inoue, Takashi, Nishimura, Chikage, Nakano, Noriko, Ishii, Yukihisa, Yuri, Kazunori, Yoh, Akio, Ishii, Tomoyuki, Takashima, Hiroki, Nishikawa, Yoshinori, Iwata, Hiroko, Iijima, and Shuhei, Nishiguchi
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Adult ,Aged, 80 and over ,Male ,Multivariate Analysis ,Humans ,Female ,Hepacivirus ,Hepatitis C, Chronic ,Middle Aged ,Esophageal and Gastric Varices ,Aged ,Body Mass Index - Abstract
Obesity is regarded as a risk factor for various benign and malignant diseases. We evaluated whether or not the body mass index (BMI) was associated with the presence of gastroesophageal varices in asymptomatic hepatitis C virus (HCV)-related compensated cirrhosis (Child-Pugh grade A status). Among a total of 794 patients of HCV-related chronic liver disease, 90 had histologically-proven cirrhosis, and 63 were classified as having compensated cirrhosis (30 had varices, and the remaining 33 did not). The values of prothrombin time (%) and platelet count were significantly lower in the patients with varices than in those without (
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- 2019
23. Serum Wisteria floribunda agglutinin‐positive Mac‐2‐binding protein for patients with chronic hepatitis B and C: a comparative study
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S Nishiguchi, Akio Ishii, Nobuhiro Aizawa, Hiroko Iijima, Takashi Nishimura, Hirayuki Enomoto, Kyohei Kishino, Ryo Takata, Yoshihiro Shimono, Kazunori Yoh, Naoto Ikeda, Yoshinori Iwata, Tomoyuki Takashima, Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, and Kunihiro Hasegawa
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Adult ,Male ,Serum ,Receptors, N-Acetylglucosamine ,medicine.medical_specialty ,Cirrhosis ,Adolescent ,Gastroenterology ,Young Adult ,03 medical and health sciences ,Hepatitis B, Chronic ,0302 clinical medicine ,Chronic hepatitis ,Antigens, Neoplasm ,Fibrosis ,Virology ,Internal medicine ,parasitic diseases ,medicine ,Humans ,Wisteria floribunda agglutinin ,Aged ,Membrane Glycoproteins ,Hepatology ,biology ,Hepatitis C ,Hepatitis C, Chronic ,Middle Aged ,Hepatitis B ,Wisteria floribunda ,biology.organism_classification ,medicine.disease ,Infectious Diseases ,030220 oncology & carcinogenesis ,Immunology ,Female ,030211 gastroenterology & hepatology ,Plant Lectins ,Mac 2 binding protein ,Protein Binding - Abstract
We compared Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+ -M2BP) levels between patients with chronic hepatitis B (n=249) and chronic hepatitis C (n=386) based on the degree of liver fibrosis. We examined WFA+ -M2BP levels in patients with F4 (cirrhosis), F3 or more (advanced fibrosis) and F2 or more (significant fibrosis) in the two groups. We further examined the relationship between five fibrosis markers and the degree of fibrosis. The WFA+ -M2BP values ranged from 0.25 cut-off index (COI) to 12.9 COI in patients with hepatitis B and 0.34-20.0 COI in patients with hepatitis C (P
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- 2016
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24. Shuffling-controlled versus strain-controlled deformation twinning: The case for HCP Mg twin nucleation
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Ju Li, Akio Ishii, and Shigenobu Ogata
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010302 applied physics ,Materials science ,Condensed matter physics ,Shuffling ,Mechanical Engineering ,Nucleation ,Ab initio ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Reaction coordinate ,Classical mechanics ,Mechanics of Materials ,Lattice (order) ,Saddle point ,0103 physical sciences ,General Materials Science ,0210 nano-technology ,Crystal twinning ,Gradient descent - Abstract
The atomistic pathways of deformation twinning can be computed ab initio, and quantified by two variables: strain which describes shape change of a periodic supercell, and shuffling which describes non-affine displacements of the internal degrees of freedom. The minimum energy path involves juxta-position of both. But if one can obtain the same saddle point by continuously increasing the strain and relaxing the internal degrees of freedom by steepest descent, we call the path strain-controlled, and vice versa. Surprisingly, we find the { 10 1 ¯ 2 } 〈 10 1 ¯ 1 ¯ 〉 twinning of Mg is shuffling-controlled at the smallest lengthscale of the irreducible lattice correspondence pattern, that is, the reaction coordinate at the level of 4 atoms is dominated by non-affine displacements, instead of strain. Shuffling-controlled deformation twinning is expected to have different temperature and strain-rate sensitivities from strain-controlled deformation twinning due to relatively weaker strength of long-range elastic interactions, in particular at the twin nucleation stage. As the twin grows large enough, however, elastic interactions and displacive character of the transformation should always turn dominant.
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- 2016
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25. Proposal of a predictive model for advanced fibrosis containing Wisteria floribunda agglutinin-positive Mac-2-binding protein in chronic hepatitis C
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Hiroki Nishikawa, Yoshiyuki Sakai, Yoshinori Iwata, Chikage Nakano, Kyohei Kishino, Shuhei Nishiguchi, Naoto Ikeda, Tomoyuki Takashima, Nobuhiro Aizawa, Takashi Nishimura, Hirayuki Enomoto, Kazunori Yoh, Yoshihiro Shimono, Kunihiro Hasegawa, Ryo Takata, Akio Ishii, and Hiroko Iijima
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Prothrombin time ,medicine.medical_specialty ,Pathology ,Multivariate analysis ,Hepatology ,medicine.diagnostic_test ,Receiver operating characteristic ,biology ,business.industry ,Wisteria floribunda ,biology.organism_classification ,Gastroenterology ,Advanced fibrosis ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,Chronic hepatitis ,030220 oncology & carcinogenesis ,Statistical significance ,Internal medicine ,Cohort ,Medicine ,030211 gastroenterology & hepatology ,business - Abstract
Aim We aimed to construct a predictive model for advanced fibrosis containing Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+-M2BP) level in patients with chronic hepatitis C (CHC) and to validate its accuracy in an independent cohort. Methods A total of 386 patients with CHC were retrospectively analyzed. For the purpose of this study, we formed a training set (n = 210) and a validation set (n = 176). In the training set, we investigated variables linked to the presence of advanced fibrosis using univariate and multivariate analyses. We constructed a formula for predicting advanced fibrosis and validated its accuracy in the validation cohort. Receiver operating characteristic curve (ROC) analysis was carried out for calculating the area under the ROC (AUROC). Results In multivariate analyses, WFA+-M2BP (P = 0.029) and prothrombin time (PT) (P = 0.018) were found to be significant predictive factors linked to the presence of advanced fibrosis; platelet count (P = 0.098) and hyaluronic acid (P = 0.078) showed borderline statistical significance for the presence of advanced fibrosis. Using these four variables (with the initials MPPH), we constructed the following formula: MPPH score = −3.584 − (0.275 × WFA+-M2BP) + (0.068 × platelet count) + (0.042 × PT) − (0.005 × hyaluronic acid). In the training and validation sets, MPPH score yielded the highest AUROCs (0.87 and 0.83) for predicting advanced fibrosis among eight serum liver fibrosis markers. Similarly, in the training and validation sets, MPPH score had the highest diagnostic accuracies for predicting advanced fibrosis among eight serum variables (81.4% and 74.4%). Conclusion Our proposed MPPH scoring system can be useful for predicting advanced fibrosis in patients with CHC.
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- 2016
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26. Clinical implications of serumWisteria floribundaagglutinin-positive Mac-2-binding protein in treatment-naïve chronic hepatitis B
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Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, Kazunori Yoh, Ryo Takata, Hiroko Iijima, Akio Ishii, Kunihiro Hasegawa, Yoshinori Iwata, Takashi Nishimura, Shuhei Nishiguchi, Hirayuki Enomoto, Naoto Ikeda, Nobuhiro Aizawa, Yoshihiro Shimono, Tomoyuki Takashima, and Kyohei Kishino
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medicine.medical_specialty ,Pathology ,Liver fibrosis ,Inflammation ,Gastroenterology ,Therapy naive ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Chronic hepatitis ,Internal medicine ,Hyaluronic acid ,medicine ,Platelet ,Hepatology ,Receiver operating characteristic ,biology ,business.industry ,Wisteria floribunda ,biology.organism_classification ,Infectious Diseases ,chemistry ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,medicine.symptom ,business - Abstract
Aim To examine the relationship between serum Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+-M2BP) levels and liver histological findings for patients with treatment naive chronic hepatitis B (CHB). Methods A total of 189 treatment naive-CHB patients were analyzed. We examined the effect of pretreatment serum WFA+-M2BP levels on histological findings compared with other laboratory markers, including aspartate aminotransferase (AST) to platelet ratio index, Fibrosis-4 index, platelet count, AST to alanine aminotransferase (ALT) ratio, and hyaluronic acid as liver fibrosis markers, and AST value, ALT value, and serum interferon-γ-inducible protein-10 level as liver inflammation markers. Results The WFA+-M2BP value ranged from 0.3 cut-off index (COI) to 12.9 COI (median value, 1.2 COI). The degree of liver fibrosis was significantly stratified according to WFA+-M2BP level in each group except for groups F2 and F3 and the degree of liver inflammation activity was significantly stratified according to WFA+-M2BP level in each group. For predicting F4, WFA+-M2BP level yielded the highest area under the receiver operating characteristic curve (AUROC) with a level of 0.87 and for predicting advanced liver fibrosis (≥F3) and significant liver fibrosis (≥F2), WFA+-M2BP level yielded the second highest AUROCs (both, 0.77) among six fibrotic markers. For predicting severe (A3) or significant liver inflammation activity (≥A2), AUROCs of WFA+-M2BP level were 0.78 and 0.76. Conclusion The WFA+-M2BP level can be a useful marker for assessing liver histological findings in patients with treatment-naive CHB, although it has several limitations.
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- 2016
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27. Comparison of sleep disorders in chronic hepatitis C patients treated with interferon-based therapy and direct acting antivirals using actigraphy
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Hirayuki Enomoto, Yoshinori Iwata, Akio Ishii, Hiroko Iijima, Hideji Nakamura, Hiroki Nishikawa, Tomoyuki Takashima, Yoshiyuki Sakai, Naoto Ikeda, Chikage Nakano, Kazunori Yoh, Takashi Nishimura, Hisato Matsunaga, Ryo Takata, Kunihiro Hasegawa, Shuhei Nishiguchi, Kyohei Kishino, Yoshihiro Shimono, and Nobuhiro Aizawa
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Simeprevir ,medicine.medical_specialty ,Hepatology ,Combination therapy ,business.industry ,Ribavirin ,Actigraphy ,Gastroenterology ,Virology ,Group B ,Pittsburgh Sleep Quality Index ,03 medical and health sciences ,chemistry.chemical_compound ,Regimen ,0302 clinical medicine ,Infectious Diseases ,chemistry ,Internal medicine ,Medicine ,030211 gastroenterology & hepatology ,030212 general & internal medicine ,Sleep onset ,business - Abstract
This study aimed to compare the severity of sleep problems between chronic hepatitis C (CHC) patients treated with interferon (IFN)-based triple therapy (pegylated [Peg]-IFN plus ribavirin [RBV] plus simeprevir [SMV]) and those who received IFN-free direct-acting antiviral (DAA) therapy. Methods Our study included 31 patients in group A (Peg-IFN/RBV/SMV combination therapy) and 41 patients in the group B (IFN-free DAA therapy). We prospectively compared the effect of each antiviral treatment regimen on sleep conditions between the two groups adding actigraphy data. Five parameters detected by actigraphy (objective assessment) and scores of the Pittsburgh Sleep Quality Index (subjective assessment, n = 30 [group A] and 35 [group B]) were estimated. The causal effect of each therapy on sleep disturbances was evaluated at baseline and at 4 weeks after commencement of therapy. Results In terms of baseline characteristics, no significant differences between groups were found, except for hepatitis C virus genotype. In group A, sustained virological response 12 rate was 83.9% (26/31), whereas in group B it was 95.1% (39/41). In group A, each score of waking after sleep onset, activity index, wake episodes, and Pittsburgh Sleep Quality Index at 4 weeks significantly increased compared to those evaluated at baseline. In group B, scores of all variables except for sleep episodes at 4 weeks did not significantly change compared to those at baseline. Conclusion Interferon-based triple therapy in patients with CHC may cause significant sleep disturbances. Interferon-free DAA therapy is less likely to deteriorate sleep conditions in patients with CHC.
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- 2016
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28. Clinical significance of serumWisteria floribundaagglutinin positive Mac-2-binding protein level in non-alcoholic steatohepatitis
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Ryo Takata, Hirayuki Enomoto, Hideji Nakamura, Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, Takashi Nishimura, Hiroko Iijima, Yoshinori Iwata, Yoshihiro Shimono, Shuhei Nishiguchi, Kunihiro Hasegawa, Akio Ishii, Tomoyuki Takashima, Naoto Ikeda, Kazunori Yoh, Kyohei Kishino, and Nobuhiro Aizawa
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medicine.medical_specialty ,Pathology ,Cirrhosis ,Hepatology ,Liver fibrosis ,Fibrosis stage ,Non alcoholic ,Biology ,medicine.disease ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,030220 oncology & carcinogenesis ,Internal medicine ,parasitic diseases ,medicine ,030211 gastroenterology & hepatology ,Clinical significance ,Steatohepatitis ,Mac 2 binding protein ,Wisteria floribunda agglutinin - Abstract
Aim To examine the relationship between the Wisteria floribunda agglutinin positive Mac-2-binding protein (WFA+-M2BP) level and histological findings for patients with non-alcoholic steatohepatitis (NASH). Methods A total of 134 NASH patients (mean age, 51.7 years) were analyzed. We examined the effect of WFA+-M2BP level on severity of liver fibrosis comparing with other laboratory markers, including aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio, AST to platelet ratio index (APRI), FIB-4 index, platelet count and hyaluronic acid as serum liver fibrosis markers. Receiver–operator curve (ROC) analysis was performed for calculating the area under the ROC (AUROC). Results The WFA+-M2B P-value ranged from 0.2 cut-off index (COI) to 9.6 COI (median, 0.9). The median values in each fibrosis stage were: 0.7 COI in F1, 0.7 COI in F2, 1.2 COI in F3 and 2.4 COI in F4 (P
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- 2016
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29. Urban Solid Waste Management in Developing Countries
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Akio Ishii and Masahiro Oseko
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Transport engineering ,Engineering ,business.industry ,050204 development studies ,0502 economics and business ,05 social sciences ,Developing country ,Urban solid waste ,050207 economics ,business ,Administrative division ,Unit (housing) - Published
- 2016
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30. Effects of Helicobacter pylori Eradication on the Platelet Count in Hepatitis C Virus-Infected Patients
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Nobuhiro Aizawa, Noriko Ishii, Shuhei Nishiguchi, Yoshinori Iwata, Yuho Miyamoto, Ryo Takata, Takashi Nishimura, Hiroki Nishikawa, Hirayuki Enomoto, Naoto Ikeda, Yukihisa Yuri, Yoshiyuki Sakai, Chikage Nakano, Hiroko Iijima, Akio Ishii, Kunihiro Hasegawa, Tomoyuki Takashima, and Kazunori Yoh
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medicine.medical_specialty ,Cirrhosis ,Hepatitis C virus ,macromolecular substances ,Chronic liver disease ,medicine.disease_cause ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Breath test ,Prothrombin time ,Helicobacter pylori ,medicine.diagnostic_test ,biology ,business.industry ,General Medicine ,medicine.disease ,biology.organism_classification ,Thrombocytopenia ,Thrombocytopenic purpura ,030220 oncology & carcinogenesis ,Splenomegaly ,Original Article ,030211 gastroenterology & hepatology ,Liver function ,business - Abstract
Background: Helicobacter pylori ( H. pylori ) infection is associated with a low platelet count in patients with immune thrombocytopenic purpura (ITP). While eradication of H. pylori is an established therapy for increasing the platelet count in ITP patients, it is unclear whether or not eradication will similarly affect the platelet counts in patients with chronic liver diseases (CLDs). We herein examined the effect of H. pylori eradication on the platelet counts in hepatitis C virus (HCV)-related CLD patients. Methods: A total of 65 patients were enrolled, and the H. pylori -positive patients were treated to eradicate H. pylori . The eradication of H. pylori was assessed using a 13 C-urea breath test 4 weeks after the completion of the therapy. In addition to the general laboratory variables of HCV-infected patients, including platelet counts, the prothrombin time (PT), and liver function markers (AST, ALT, total bilirubin, alkaline phosphatase, and albumin), we also investigated the presence of splenomegaly via ultrasonography. The platelet counts were measured at 1, 3, and 6 months after the final eradication therapy in order to assess the success of H. pylori eradication. Results: Of the 65 patients with HCV-related CLD, 30 were found to be H. pylori -positive. The oral treatment regimen succeeded in eliminating H. pylori in 19 patients. These H. pylori -eradicated patients included eight males and 11 females, and 15 (78.9%) had liver cirrhosis. Regarding the patients who failed to achieve H. pylori eradication, their platelet counts did not markedly differ between pre- and post-treatment. Regarding the patients with H. pylori eradication, the platelet counts tended to increase 6 months after the treatment (9.2 ± 2.9 × 10 3 /μL vs. 10.1 ± 3.7 × 10 3 /μL, P = 0.085). We also found that the platelet count was significantly increased after the eradication in patients without splenomegaly (9.8 ± 2.8 ×10 3 /μL vs. 11.0 ± 3.7 ×10 3 /μL, P = 0.040). Regarding the seven patients whose platelet count increased by more than 20 × 10 3 /μL after anti- H. pylori treatment, most (6/7, 85.7%) did not have splenomegaly. Conclusion: H. pylori eradication may increase the platelet count in HCV-positive patients, particularly those without splenomegaly. J Clin Med Res. 2016;8(12):854-858 doi: http://dx.doi.org/10.14740/jocmr2725w
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- 2016
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31. First-principles adaptive-boost accelerated molecular dynamics simulation with effective boost potential construction methods: a study of Li diffusion in Si crystal
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Masahiro Yamamoto, Shuhei Shinzato, Akio Ishii, Shigenobu Ogata, and Taisuke Ozaki
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Crystal ,Molecular dynamics ,Materials science ,Physics and Astronomy (miscellaneous) ,General Engineering ,General Physics and Astronomy ,First principle ,Thermodynamics ,Diffusion (business) ,Thermal diffusivity ,Arrhenius plot - Published
- 2020
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32. Energetics of heterogeneous Mg {101¯2} deformation twinning migration using an atomistically informed phase-field model
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Akio Ishii
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Materials science ,General Computer Science ,Condensed matter physics ,General Physics and Astronomy ,General Chemistry ,Activation energy ,Gibbs free energy ,Stress (mechanics) ,Computational Mathematics ,symbols.namesake ,Mechanics of Materials ,Phase (matter) ,Atomic model ,symbols ,General Materials Science ,Density functional theory ,Deformation (engineering) ,Crystal twinning - Abstract
We have constructed an atomistically informed phase-field model for the quantitative energetic analysis of phase transformations. In our model, to describe the general phase transformation with a non-linear correlation between displacive and diffusive modes, we have defined two order parameters, γ and ϕ , which describe the lattice distortion (displacive mode) and shuffling (diffusive mode), respectively. Our method provides a way to introduce the energetics from atomistic simulations to the phase-field model, describes γ and ϕ in an atomic model, and derives phase-field parameters from the free energy calculated by atomistic simulation. As an application of our model, we used the energetics obtained from atomistic simulations using a density functional theory potential, and we calculated the free energy change during the heterogeneous { 10 1 ¯ 2 } twin migration of hexagonally close-packed (HCP) Mg, which can be considered as a lattice distortion and shuffling mixed phase transformation, by combining our phase-field model with the nudged elastic band method. The activation energy, and the critical nucleus size of the heterogeneous { 10 1 ¯ 2 } twin migration under a set stress were derived. The critical c-axis tensile stress (athermal stress), at which the activation energy becomes zero, is consistent with the experimental yield stress of { 10 1 ¯ 2 } for the twinning deformation of HCP Mg nanopillars in tensile tests. The critical nucleus size of the heterogeneous { 10 1 ¯ 2 } twin migration is on the range of nanometers under several hundred megapascals stress, which is consistent with the experimental observation of nanotwins.
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- 2020
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33. Amplification of bacterial genomic DNA from all ascitic fluids with a highly sensitive polymerase chain reaction
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Ryo Takata, Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, Kazunori Yoh, Tomoyuki Takashima, Yukihisa Yuri, Akio Matsuhisa, Yoshinori Iwata, Hirayuki Enomoto, Noriko Ishii, Shuhei Nishiguchi, Hiroko Iijima, Yuho Miyamoto, Kunihiro Hasegawa, Takashi Nishimura, Nobuhiro Aizawa, Akio Ishii, Shin-ichi Inoue, and Naoto Ikeda
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DNA, Bacterial ,Liver Cirrhosis ,Male ,0301 basic medicine ,Cancer Research ,polymerase chain reaction ,Biology ,DNA, Ribosomal ,Biochemistry ,law.invention ,Bacterial genetics ,ascites ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,law ,RNA, Ribosomal, 16S ,Genetics ,Ascitic Fluid ,Humans ,bacterial translocation ,Molecular Biology ,Gene ,Polymerase chain reaction ,Bacteria ,Articles ,Ribosomal RNA ,16S ribosomal RNA ,16S ribosomal RNA gene ,Molecular biology ,spontaneous bacterial peritonitis ,genomic DNA ,030104 developmental biology ,Oncology ,chemistry ,Molecular Medicine ,Female ,030211 gastroenterology & hepatology ,Primer (molecular biology) ,Genome, Bacterial ,DNA - Abstract
Due to varying positive rates of polymerase chain reaction (PCR) amplification, interpretation of conventional PCR results for non-infectious ascites remains problematic. The present study developed a highly sensitive PCR protocol and investigated the positive rate of PCR for the 16S ribosomal (r)RNA gene in non-infectious ascites. Following the design of a new PCR primer pair for the 16S rRNA gene (800F and 1400R), the sequences of PCR products were analyzed and the lower limit for bacterial DNA detection evaluated. The positive rate of PCR for 16S rRNA gene in non-infectious ascites was also evaluated. PCR with the primer pair amplified the genomic DNA of 16S rRNA genes of major disease-causing bacterial strains. Additionally, PCR with this primer pair provided highly sensitive detection of bacterial genomic DNA (lower limit, 0.1 pg of template DNA). When DNA samples isolated from ascites were used, the 16S rRNA gene was amplified independently of the presence of bacterial infection. PCR products contained the genomic DNA fragments of multiple bacterial species. Bacterial genomic DNA can be amplified from all ascitic fluids using a highly sensitive PCR protocol. Careful attention is required to interpret the results based on simple amplification of 16S rRNA gene with conventional PCR.
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- 2018
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34. Relationship between skeletal muscle mass and liver fibrosis markers for patients with hepatitis C virus related liver disease
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Yukihisa Yuri, Nobuhiro Aizawa, Ryo Takata, Yoshinori Iwata, Akio Ishii, Yuho Miyamoto, Hiroki Nishikawa, Hirayuki Enomoto, Yoshiyuki Sakai, Hiroko Iijima, Tomoyuki Takashima, Takashi Nishimura, Noriko Ishii, Chikage Nakano, Shuhei Nishiguchi, Kazunori Yoh, Naoto Ikeda, and Kunihiro Hasegawa
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Adult ,Liver Cirrhosis ,Male ,medicine.medical_specialty ,Multivariate analysis ,Hepatitis C virus ,Liver fibrosis ,Biopsy ,Observational Study ,medicine.disease_cause ,Gastroenterology ,03 medical and health sciences ,Liver disease ,0302 clinical medicine ,Japan ,Internal medicine ,medicine ,Humans ,chronic hepatitis C ,Muscle, Skeletal ,Aged ,Aged, 80 and over ,medicine.diagnostic_test ,Receiver operating characteristic ,business.industry ,skeletal muscle mass loss ,predictive ability ,General Medicine ,Hepatitis C ,Hepatitis C, Chronic ,Middle Aged ,medicine.disease ,liver fibrosis marker ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,Female ,business ,Tomography, X-Ray Computed ,Body mass index ,Biomarkers ,Research Article - Abstract
We aimed to elucidate the relationship between serum liver fibrosis markers (Mac-2 binding protein glycosylation isomer (M2BPGi), FIB-4 index, aspartate aminotransferase to platelet ratio index and hyaluronic acid), and skeletal muscle mass and to investigate factors linked to skeletal muscle mass loss (SMML) in patients with chronic hepatitis C (CHC, n = 277, median age = 64 years). We defined patients with psoas muscle index [PMI, sum of bilateral psoas muscle mass calculated by manual trace method at the lumber 3 level on the computed tomography images divided by height squared (cm2/m2)] less than 6.36 cm2/m2 for male and 3.92 cm2/m2 for female as those with SMML based on the recommendations in current guidelines. Receiver operating curve (ROC) analysis was performed for predicting SMML in 4 liver fibrosis markers and parameters linked to SMML were also investigated in the univariate and multivariate analyses. In terms of liver fibrosis stages, F4 was observed in 115 patients, F3 in 67, F2 in 38, F1 in 53, and F0 in 4. The median (range) PMI for male and female were 6.198 (2.999–13.698) and 4.100 (1.691–7.052) cm2/m2, respectively. There were 72 male patients with SMML (55.4%) and 58 female patients with SMML (39.5%) (P = .0112). In both male and female, a significant inverse correlation between PMI and levels of liver fibrosis markers was observed in all liver fibrosis markers. ROC analyses for predicting SMML revealed that FIB-4 index had the highest area under the ROC (AUC = 0.712), followed by M2BPGi (AUC = 0.692). In the multivariate analysis of factors linked to SMML, gender (P = .0003), body mass index (P
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- 2018
35. Hydrogen embrittlement controlled by reaction of dislocation with grain boundary in alpha-iron
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Akio Ishii, Wen-Tong Geng, Nobuyuki Ishikawa, Jun-Ping Du, Liang Wan, Hajime Kimizuka, Shigenobu Ogata, and Q.S. Mei
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Materials science ,Hydrogen ,chemistry.chemical_element ,FOS: Physical sciences ,02 engineering and technology ,01 natural sciences ,Metal ,Modelling methods ,0103 physical sciences ,General Materials Science ,Stress concentration ,010302 applied physics ,Condensed Matter - Materials Science ,Mechanical Engineering ,Materials Science (cond-mat.mtrl-sci) ,021001 nanoscience & nanotechnology ,chemistry ,Mechanics of Materials ,Chemical physics ,visual_art ,visual_art.visual_art_medium ,Grain boundary ,Crystallite ,Dislocation ,0210 nano-technology ,Hydrogen embrittlement - Abstract
Hydrogen atoms absorbed by metals in the hydrogen-containing environments can lead to the premature fracture of the metal components used in load-bearing conditions. Since metals used in practice are mostly polycrystalline, grain boundaries (GBs) can play an important role in hydrogen embrittlement of metals. Here we show that the reaction of GB with lattice dislocations is a key component in hydrogen embrittlement mechanism for polycrystalline metals. We use atomistic modeling methods to investigate the mechanical response of GBs in alpha-iron with various hydrogen concentrations. Analysis indicates that dislocations impingement and emission on the GB cause the GB to locally transform into an activated state with a more disordered atomistic structure, and introduce a local stress concentration. The activation of the GB segregated with hydrogen atoms can greatly facilitate decohesion of the GB. We show that the hydrogen embrittlement model proposed here can give better explanation of many experimental observations.
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- 2018
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36. Impact of serumWisteria floribundaagglutinin positive Mac-2-binding protein and serum interferon-γ-inducible protein-10 in primary biliary cirrhosis
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Hiroko Iijima, Ryo Takata, Yoshinori Iwata, Hiroki Nishikawa, Shuhei Nishiguchi, Takashi Nishimura, Hirayuki Enomoto, Yoshiyuki Sakai, Chikage Nakano, Naoto Ikeda, Kunihiro Hasegawa, Akio Ishii, Tomoyuki Takashima, Kazunori Yoh, and Nobuhiro Aizawa
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medicine.medical_specialty ,Pathology ,Cirrhosis ,Hepatology ,Inflammation ,Biology ,medicine.disease ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,Primary biliary cirrhosis ,Interferon γ ,Fibrosis ,030220 oncology & carcinogenesis ,Internal medicine ,medicine ,030211 gastroenterology & hepatology ,medicine.symptom ,Alanine aminotransferase ,Mac 2 binding protein ,Wisteria floribunda agglutinin - Abstract
Aim We aimed to examine the relationship between serum Wisteria floribunda agglutinin positive Mac-2-binding protein (WFA+-M2BP) levels and serum interferon-γ-inducible protein-10 (IP-10) levels and liver histological findings for patients with primary biliary cirrhosis (PBC) compared with other laboratory fibrotic or inflammatory parameters. Methods A total of 57 PBC patients were analyzed. Receiver–operator curve (ROC) analysis was performed for calculating the area under the ROC (AUROC) for WFA+-M2BP, IP-10 and four serum fibrosis markers for the presence of liver cirrhosis (F4) or advanced fibrosis (F3 or F4). Similarly, ROC analysis of WFA+-M2BP, IP-10, aspartate aminotransferase and alanine aminotransferase for the presence of severe inflammation activity (A3) was performed. Results There were eight men and 49 women (median age, 59 years). As for histological findings, F4 was observed in five patients, F3 in 11, F2 in 17, F1 in 24 and F0 in zero, whereas A3 was observed in seven patients, A2 in 27, A1 in 19 and A0 in four. The WFA+-M2BP levels ranged from 0.5 cut-off index (COI) to 13.6 COI (median, 1.8), while serum IP-10 levels ranged 121.9–1835.9 pg/mL (median, 571.5). For predicting liver cirrhosis, WFA+-M2BP yielded the highest AUROC (0.97, P
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- 2015
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37. A New Metabolism-Related Index Correlates with the Degree of Liver Fibrosis in Hepatitis C Virus-Positive Patients
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Kunihiro Hasegawa, Akio Ishii, Hiroko Iijima, Ryo Takata, Hirayuki Enomoto, Nobuhiro Aizawa, Hiroyasu Imanishi, Shuhei Nishiguchi, Yoshiyuki Sakai, Naoto Ikeda, Yoshinori Iwata, Tomoyuki Takashima, Kazunori Yoh, Kenji Hashimoto, Masaki Saito, Hironori Tanaka, Hideji Nakamura, and Tomoko Aoki
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medicine.medical_specialty ,Pathology ,Cirrhosis ,Article Subject ,Hepatitis C virus ,medicine.disease_cause ,Gastroenterology ,chemistry.chemical_compound ,Fibrosis ,Internal medicine ,Medicine ,lcsh:RC799-869 ,Prothrombin time ,Hepatology ,medicine.diagnostic_test ,business.industry ,Albumin ,medicine.disease ,Hepatitis C Virus Positive ,chemistry ,lcsh:Diseases of the digestive system. Gastroenterology ,Glycated hemoglobin ,Liver function ,business ,Research Article - Abstract
Background. Only a few biomarkers based on metabolic parameters for evaluating liver fibrosis have been reported. The aim of this study was to investigate the relevance of an index obtained from three metabolic variables (glycated albumin: GA, glycated hemoglobin: HbA1c, and branched-chain amino acids to tyrosine ratio: BTR) to the degree of liver fibrosis in hepatitis C virus virus- (HCV-) positive patients.Methods. A total of 394 HCV-positive patients were assessed based on the values of a new index (GA/HbA1c/BTR). The index findings were used to investigate the relationship with the degree of liver fibrosis.Results. The new index showed an association with the stage of fibrosis (METAVIR scores: F0-1: 0.42 ± 0.10, F2: 0.48 ± 0.15, F3: 0.56 ± 0.22, and F4: 0.71 ± 0.30). The index was negatively correlated with three variables of liver function: the prothrombin time percentage (P<0.0001), albumin level (P<0.0001), and cholinesterase level (P<0.0001). The new index showed a higher correlation related to liver function than FIB-4 and the APRI did. In addition, the index showed a higher AUROC value than that of FIB-4 and the APRI for prediction of liver cirrhosis.Conclusion. The new metabolism-related index, GA/HbA1c/BTR value, is shown to relate to the degree of liver fibrosis in HCV-positive patients.
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- 2015
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38. Atomistic study on cross-slip mechanism of 〈a〉 screw dislocations in pure Mg
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Shigenobu Ogata, Hajime Kimizuka, Akio Ishii, and Kazuhei Takahashi
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Mechanism (engineering) ,Materials science ,Condensed matter physics ,Cross Slip - Published
- 2016
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39. Clinical impact of physical exercise on sleep disorder as assessed by actigram in patients with chronic pancreatitis: a study protocol for a randomised controlled trial
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Akio Ishii, Ryo Takata, Yuho Miyamoto, Naoto Ikeda, Noriko Ishii, Shuhei Nishiguchi, Hiroki Nishikawa, Tomoyuki Takashima, Hirayuki Enomoto, Yoshiyuki Sakai, Chikage Nakano, Kunihiro Hasegawa, Yukihisa Yuri, Yoshinori Iwata, Nobuhiro Aizawa, Kazunori Yoh, Hiroko Iijima, and Takashi Nishimura
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medicine.medical_specialty ,Physical exercise ,law.invention ,chronic pancreatitis ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,Quality of life ,law ,Weight loss ,Clinical endpoint ,Medicine ,030212 general & internal medicine ,psychological stress ,Sleep disorder ,business.industry ,Gastroenterology ,abdominal pain ,medicine.disease ,Institutional review board ,Pancreatitis ,quality of life ,Physical therapy ,030211 gastroenterology & hepatology ,medicine.symptom ,business - Abstract
Introduction In most chronic pancreatitis (CP) cases, malabsorption, pain, and weight loss are the leading clinical symptoms, which significantly worsen the quality of life (QOL) and decreased QOL in patients with CP can cause sleep disorder. There is a growing body of evidence that recognises the favourable effects of physical exercise (PE), however, there are limited data currently available concerning patients with CP undergoing PE. Actigram is a device for gathering objective sleep/awake data in the natural sleeping surroundings over an extended time period. In this study, we will aim to prospectively investigate the effect of PE on sleep disorder as assessed by actigram in patients with CP. Methods and analysis This study is a non-double-blind randomised controlled trial. Study participants will be randomised into the PE group and the control group. When registering patients, precise assessment for nutritional status and daily physical activities will be undertaken in each study patient. In the PE group, physical activities equal to or higher than walking for 60 min/day should be strongly recommended. Sleep quality using actigram will be prospectively compared in the two groups. The primary endpoint is the activity index in actigram at 12 weeks. Ethics and dissemination Ethical approval for the study was granted by the Institutional Review Board at Hyogo College of Medicine (approval number 2767). Results will be presented at relevant conferences and submitted to an appropriate journal following trial closure and analysis. Trial registration number UMIN000029265 (https://upload.umin.ac.jp/); Pre-results.
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- 2017
40. Clinical influence of exercise therapy on sarcopenia in patients with chronic pancreatitis: a study protocol for a randomised controlled trial
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Ryo Takata, Kazunori Yoh, Hirayuki Enomoto, Yukihisa Yuri, Kunihiro Hasegawa, Yuho Miyamoto, Hiroko Iijima, Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, Noriko Ishii, Shuhei Nishiguchi, Yoshinori Iwata, Takashi Nishimura, Tomoyuki Takashima, Nobuhiro Aizawa, Akio Ishii, and Naoto Ikeda
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Abdominal pain ,medicine.medical_specialty ,law.invention ,chronic pancreatitis ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Clinical endpoint ,Protocol ,Medicine ,030212 general & internal medicine ,business.industry ,Incidence (epidemiology) ,Gastroenterology ,abdominal pain ,Institutional review board ,medicine.disease ,nutritional status ,nutrition ,Sarcopenia ,Basal metabolic rate ,Physical therapy ,Pancreatitis ,030211 gastroenterology & hepatology ,medicine.symptom ,business - Abstract
Introduction and purposeChronic pancreatitis (CP) involves progressive inflammatory changes to the pancreas and can lead to permanent structural damage and impairment of both endocrine and exocrine functions. Current reports highlight a rise in the incidence and prevalence of CP. However, there is limited data currently available concerning patients with CP undergoing exercise therapy (ET). We aim to prospectively examine the influence of ET on sarcopenia in patients with CP.Methods and analysisA detailed evaluation of the nutritional condition and the daily physical activities of each participant will be conducted prior to entering the study. Our patients will be randomly allocated to either: (1) the ET group or (2) the control group. In the ET group, our patients with CP will receive nutritional guidance once a month. The patients with CP will also be instructed to perform exercises with >3 metabolic equivalents (mets; energy consumption in physical activities/resting metabolic rate) for 60 min/day and to perform exercises >23 mets/week. The primary end point will be an improvement in sarcopenia, defined as an increase in muscle mass and muscle strength, at 3 months postrandomisation. A comparison of the amelioration of sarcopenia in the two groups will be undertaken.Ethics and disseminationThe Institutional Review Board at Hyogo College of Medicine approved this study protocol (approval no. 2766). Final data will be publicly announced. A report releasing the study results will be submitted for publication to an appropriate journal.Trial registration numberUMIN000029263; Pre-results. No patient is registered at the submission of our manuscript.
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- 2017
41. Effect of physical exercise on sarcopaenia in patients with overt hepatic encephalopathy: a study protocol for a randomised controlled trial
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Kazunori, Yoh, Hiroki, Nishikawa, Hirayuki, Enomoto, Yoshinori, Iwata, Akio, Ishii, Yukihisa, Yuri, Noriko, Ishii, Yuho, Miyamoto, Kunihiro, Hasegawa, Chikage, Nakano, Ryo, Takata, Takashi, Nishimura, Nobuhiro, Aizawa, Yoshiyuki, Sakai, Naoto, Ikeda, Tomoyuki, Takashima, Hiroko, Iijima, and Shuhei, Nishiguchi
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Hepatology ,liver cirrhosis ,hepatic encephalopathy ,malnutrition ,liver - Abstract
Introduction Limited data are currently available for patients with overt hepatic encephalopathy (OHE)) receiving physical exercise (PE). The aim of the current study is to prospectively examine the effect of PE on sarcopaenia in patients with OHE. Methods and analysis At the time of patient recruitment, a precise assessment for nutritional status and daily physical activities will be performed in each subject. Study participants will be randomly assigned into two groups: (1) the PE group and (2) the control group. In the PE group, we will conduct guidance to study participants once a month at the outpatient nutrition guidance room. We will also instruct them to do exercise with >3 metabolic equivalents (mets; energy consumption in physical activities/resting metabolic rate) for 60 min per day and to do exercise >23 mets per week. Improvement of sarcopaenia as defined by muscle mass and muscle strength at 3 months after the randomisation will be the primary endpoint. Sarcopaenia will be defined based on the current Japanese guidelines. We prospectively compared the improvement of sarcopaenia in the two groups. Ethics and dissemination This study has received approval from the Institutional Review Board at Hyogo college of medicine (approval no. 2768). Final data will be publicly disseminated irrespective of the study results. A report releasing study results will be submitted for publication in an appropriate journal after completion of data collection. Trial registration number UMIN000029248; Pre-results. No patient is registered at the submission of our manuscript.
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- 2017
42. Impact of Virtual Touch Quantification in Acoustic Radiation Force Impulse for Skeletal Muscle Mass Loss in Chronic Liver Diseases
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Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, Yuho Miyamoto, Akio Ishii, Kazunori Yoh, Hiroko Iijima, Yukihisa Yuri, Hirayuki Enomoto, Takashi Nishimura, Nobuhiro Aizawa, Tomoyuki Takashima, Ryo Takata, Kunihiro Hasegawa, Noriko Ishii, Shuhei Nishiguchi, Yoshinori Iwata, and Naoto Ikeda
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Male ,Multivariate analysis ,Body Mass Index ,0302 clinical medicine ,Electric Impedance ,Medicine ,Aged, 80 and over ,Nutrition and Dietetics ,Receiver operating characteristic analysis ,Age Factors ,Middle Aged ,virtual touch quantification ,medicine.anatomical_structure ,bio-electronic impedance analysis ,liver fibrosis marker ,030220 oncology & carcinogenesis ,Area Under Curve ,Cardiology ,Body Composition ,Elasticity Imaging Techniques ,030211 gastroenterology & hepatology ,Female ,skeletal muscle mass ,predictive ability ,Adult ,medicine.medical_specialty ,Adolescent ,education ,Independent predictor ,Article ,End Stage Liver Disease ,03 medical and health sciences ,Young Adult ,Internal medicine ,mental disorders ,Humans ,In patient ,Muscle, Skeletal ,Aged ,Receiver operating characteristic ,business.industry ,fungi ,Skeletal muscle ,Reproducibility of Results ,Skeletal muscle mass ,Surgery ,ROC Curve ,business ,Body mass index ,Food Science - Abstract
Background and aims: We sought to clarify the relationship between virtual touch quantification (VTQ) in acoustic radiation force impulse and skeletal muscle mass as assessed by bio-electronic impedance analysis in patients with chronic liver diseases (CLDs, n = 468, 222 males and 246 females, median age = 62 years). Patients and methods: Decreased skeletal muscle index (D-SMI) was defined as skeletal muscle index (SMI)
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- 2017
43. Effect of psoas muscle mass after endoscopic therapy for patients with esophageal varices
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Noriko Ishii, Shuhei Nishiguchi, Tomoyuki Takashima, Yukihisa Yuri, Yuho Miyamoto, Hiroki Nishikawa, Naoto Ikeda, Hiroko Iijima, Yoshiyuki Sakai, Kazunori Yoh, Chikage Nakano, Akio Ishii, Ryo Takata, Kunihiro Hasegawa, Hirayuki Enomoto, Takashi Nishimura, Nobuhiro Aizawa, and Yoshinori Iwata
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Adult ,Liver Cirrhosis ,Male ,medicine.medical_specialty ,Cirrhosis ,Carcinoma, Hepatocellular ,Observational Study ,Esophageal and Gastric Varices ,Gastroenterology ,03 medical and health sciences ,Liver disease ,Young Adult ,0302 clinical medicine ,Esophageal varices ,Internal medicine ,medicine ,Carcinoma ,esophageal varices ,Humans ,Survival analysis ,Aged ,Psoas Muscles ,Retrospective Studies ,Aged, 80 and over ,Lumbar Vertebrae ,business.industry ,muscle mass depletion ,Retrospective cohort study ,General Medicine ,Organ Size ,Middle Aged ,medicine.disease ,Prognosis ,Model for End-stage Liver Disease ,Survival Analysis ,serum sodium ,comparison ,030220 oncology & carcinogenesis ,Hepatocellular carcinoma ,Cohort ,030211 gastroenterology & hepatology ,Female ,Esophagoscopy ,business ,Tomography, X-Ray Computed ,Follow-Up Studies ,Research Article - Abstract
We aimed to investigate the impact of decrease of muscle mass on survival after eradication of esophageal varices (EVs) treated by endoscopic therapies as a primary prophylaxis in patients with liver cirrhosis (LC). In all, 177 LC individuals with EVs undergoing endoscopic therapies were analyzed. We retrospectively examined the impact of muscle mass decrease as determined by psoas muscle mass (PMM) at the third lumber on computed tomography (depletion of PMM [DPMM]) on survival as compared with serum sodium combined Model for End-stage Liver Disease (MELD-Na). In comparison of the effects of these parameters, we used time-dependent receiver-operating characteristics (ROC) analysis. We also investigated parameters related to overall survival in the univariate and multivariate analyses. This study included 116 males and 61 females with a median age of 66 years. The median follow-up periods were 2.7 years (range 0.1–9.6 years). In all, 110 patients (62.1%) had DPMM. The median MELD-Na score was 7.200 (range −3.451 to 30.558). The MELD-Na score in patients with DPMM (median 7.685) was significantly higher than that in patients without DPMM (median 6.235) (P = .0212). In the multivariate analysis, presence of hepatocellular carcinoma (P
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- 2017
44. Effect of dexmedetomidine in the prophylactic endoscopic injection sclerotherapy for oesophageal varices: a study protocol for prospective interventional study
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Hiroki Nishikawa, Yoshiyuki Sakai, Takashi Nishimura, Chikage Nakano, Hiroko Iijima, Hirayuki Enomoto, Yoshinori Iwata, Nobuhiro Aizawa, Akio Ishii, Kazunori Yoh, Ryo Takata, Noriko Ishii, Shuhei Nishiguchi, Tomoyuki Takashima, Yuho Miyamoto, Naoto Ikeda, Yukihisa Yuri, and Kunihiro Hasegawa
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medicine.medical_specialty ,medicine.drug_class ,medicine.medical_treatment ,Sedation ,Analgesic ,03 medical and health sciences ,0302 clinical medicine ,Sclerotherapy ,medicine ,GASTROINTESINAL ENDOSCOPY ,Dexmedetomidine ,CIRRHOSIS ,business.industry ,OESOPHAGEAL VARICES ,Gastroenterology ,Endoscopy ,Surgery ,Pentazocine ,030220 oncology & carcinogenesis ,Anesthesia ,Sedative ,ENDOSCOPIC PROCEDURES ,Midazolam ,030211 gastroenterology & hepatology ,medicine.symptom ,Varices ,business ,medicine.drug - Abstract
Background Dexmedetomidine (DEX) is a novel, highly selective α2-adrenoceptor agonist that elicits sedative, amnestic, sympatholytic and analgesic effects in patients. Several Japanese investigators have reported the clinical usefulness of DEX for sedation in endoscopic therapies for gastrointestinal malignancies; however, there have been limited data regarding the usefulness and safety of DEX for sedation during endoscopic procedures for oesophageal varices (OVs), such as endoscopic injection sclerotherapy (EIS). In this prospective, single-arm interventional study, we aimed to elucidate these issues. Methods Patients who require two or more sessions of prophylactic EIS for the treatment of OVs will be enrolled in this prospective interventional study. EIS procedures include two methods: (1) sedation during endoscopic procedures will be performed using conventional methods (pentazocine (PNZ) and midazolam (MDZ)), and (2) sedation during endoscopic procedures will be performed using PNZ, low-dose MDZ and DEX. These two methods were randomly assigned in the first and second EIS. The effect and safety of these two procedures with respect to patient sedation are to be compared with the degree of sedation evaluated using the Bispectral Index monitoring system (Aspect Medical Systems, Norwood, Massachusetts, USA). Ethics and dissemination This study received approval from the Institutional Review Board at Hyogo College of Medicine (approval no. 2324). The authors are committed to publishing the study results as widely as possible in peer-reviewed journals, and to ensuring that appropriate recognition is provided to everyone who is working on this study. Trial registration number UMIN000026688; Pre-results.
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- 2017
45. Effect of pretreatment psoas muscle mass on survival for patients with unresectable pancreatic cancer undergoing systemic chemotherapy
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Nobuhiro Aizawa, Hiroki Nishikawa, Yoshiyuki Sakai, Chikage Nakano, Hiroko Iijima, Yoshinori Iwata, Yuho Miyamoto, Yukihisa Yuri, Takashi Nishimura, Akio Ishii, Hirayuki Enomoto, Tomoyuki Takashima, Ryo Takata, Noriko Ishii, Shuhei Nishiguchi, Kunihiro Hasegawa, Kazunori Yoh, and Naoto Ikeda
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Prothrombin time ,Oncology ,Cancer Research ,medicine.medical_specialty ,medicine.diagnostic_test ,Performance status ,business.industry ,Cancer ,Articles ,medicine.disease ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Internal medicine ,Pancreatic cancer ,Cohort ,medicine ,Clinical endpoint ,030211 gastroenterology & hepatology ,Stage (cooking) ,business ,Body mass index - Abstract
To the best of our knowledge, there are few previous studies that have investigated the effect of decreased skeletal muscle mass (DSMM) on survival in patients with unresectable advanced pancreatic cancer (APC) who are undergoing systemic chemotherapy. Thus, the present study aimed to investigate the impact of DSMM, as determined by the psoas muscle index (PMI) following computed tomography and prior to systemic chemotherapy, on the outcomes of patients with unresectable APC (n=61). The primary endpoint used was the overall survival (OS) rate. The OS rates in the PMI-High group (exceeds the median PMI value in each gender) were retrospectively compared with those in the PMI-Low group (below the median PMI value in each gender), and factors associated with OS were investigated using univariate and multivariate analyses. The study cohort included 31 male and 30 female patients with a median age of 72 years, 13 of whom were stage IVA, and 48 were stage IVB. The median PMI in males was 4.3 cm2/m2 (range, 1.6-8.2 cm2/m2), while that in females was 2.3 cm2/m2 (range, 0.7-6.1 cm2/m2). The proportion of patients with performance status 0 in the PMI-High group was significantly high, compared with that in the PMI-Low group [83.3% (25/30) vs. 58.1% (18/31); P=0.0486]. Body mass index in the PMI-High group was significantly higher compared with that in the PMI-Low group (P=0.0154). The 1-year cumulative survival rate was 43.3% in the PMI-High group and 12.9% in the PMI-Low group (P=0.0027). Following multivariate analysis, PMI (P=0.0036), prothrombin time (P=0.0044) and carbohydrate antigen 19-9 (P=0.0451) were identified to be significant predictors of OS. In conclusion, DSMM, as determined by the PMI, could be a significant predictor of prognosis in patients with unresectable APC who are receiving systemic chemotherapy.
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- 2017
46. Two randomized controlled studies comparing the nutritional benefits of branched-chain amino acid (BCAA) granules and a BCAA-enriched nutrient mixture for patients with esophageal varices after endoscopic treatment
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Masaki Saito, Yoshinori Iwata, Akio Ishii, Hirayuki Enomoto, Yoshiyuki Sakai, Shuhei Nishiguchi, Hiroko Iijima, Nobuhiro Aizawa, Tomoyuki Takashima, Naoto Ikeda, Hironori Tanaka, and Kazunori Yoh
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Blood Glucose ,Liver Cirrhosis ,Male ,medicine.medical_specialty ,Cirrhosis ,Branched-chain amino acid ,Nutritional Status ,Esophageal varices ,Esophageal and Gastric Varices ,Gastroenterology ,Body Mass Index ,law.invention ,Nutritional therapy ,chemistry.chemical_compound ,Randomized controlled trial ,law ,Internal medicine ,medicine ,Humans ,Medical nutrition therapy ,Aged ,Aged, 80 and over ,Postoperative Care ,chemistry.chemical_classification ,Original Article—Liver, Pancreas, and Biliary Tract ,business.industry ,Body Weight ,Endoscopic treatment ,Proteins ,Middle Aged ,Hepatology ,medicine.disease ,Amino acid ,chemistry ,Dietary Supplements ,Female ,Esophagoscopy ,Energy Metabolism ,business ,Amino Acids, Branched-Chain ,Abdominal surgery - Abstract
Background The usefulness of branched-chain amino acid (BCAA) granules and BCAA-enriched nutrient mixtures for patients with liver cirrhosis is often reported. However, no randomized controlled studies have investigated the usefulness of these supplements in the nutritional intervention of cirrhotic patients receiving endoscopic treatment for esophageal varices. Methods Patients without BCAA before endoscopic treatment were divided into study 1, and those who received BCAA were divided into study 2. In study 1, 44 eligible patients were divided into a control group (n = 13), a general liquid nutrient (snack) group (n = 15), and a BCAA-enriched nutrient mixture (BCAA-EN) group (n = 16). In study 2, 48 eligible patients were divided into a BCAA group (n = 24) and a BCAA-EN group (n = 24). The nutritional status including non-protein respiratory quotient (NPRQ) levels, weight gain, and albumin were evaluated on days 0, 7, and 50. Results In study 1, the BCAA-EN group showed significant improvement in NPRQ levels on day 7 as compared with the snack group. In study 2, the BCAA-EN group showed significant improvement in NPRQ levels on day 7 and in weight levels on day 50 relative to the BCAA group, while the BCAA group showed improved serum albumin levels on day 7 compared to the BCAA-EN group. Conclusions The BCAA-enriched nutrient mixture maintained NPRQ and weight in cirrhotic patients. Our findings suggest that supplements including both BCAA and a nutritional energy supplement would be beneficial for cirrhotic patients undergoing endoscopic treatment for esophageal varices. Electronic supplementary material The online version of this article (doi:10.1007/s00535-014-0950-2) contains supplementary material, which is available to authorized users.
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- 2014
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47. Usefulness of liver fibrosis markers ELF in chronic hepatitis
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Kazunori Yo, Shuhei Nishiguchi, Kunihiro Hasegawa, Jiro Fujimoto, Takashi Nishimura, Osamu Nakashima, Tomoko Aoki, Hirohisa Yano, Hiroki Nishikawa, Hirayuki Enomoto, Seiichi Hirota, Yoshiyuki Sakai, Yoshihiro Shimono, Chikage Nakano, Hiroko Iijima, Ryo Takata, Yoshinori Iwata, Akio Ishii, Nobuhiro Aizawa, Naoto Ikeda, Kyohei Kishino, Masayoshi Kage, and Tomoyuki Takashima
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medicine.medical_specialty ,Hepatology ,Chronic hepatitis ,business.industry ,Liver fibrosis ,Internal medicine ,medicine ,business ,Gastroenterology - Published
- 2015
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48. Entropic effect on creep in nanocrystalline metals
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Akio Ishii, Yun-Jiang Wang, and Shigenobu Ogata
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Materials science ,Polymers and Plastics ,Enthalpy ,Metals and Alloys ,Nucleation ,Thermodynamics ,Nanocrystalline material ,Electronic, Optical and Magnetic Materials ,Orders of magnitude (entropy) ,Molecular dynamics ,Creep ,Ceramics and Composites ,Dislocation ,Entropic force - Abstract
We report a significant entropic effect on creep of nanocrystalline metal using molecular dynamics. Our simulations reveal that the activation entropy may contribute a multiplicative factor of many orders of magnitude to the steady-state creep rate. The relationship between activation entropy and enthalpy obeys an empirical Meyer–Neldel compensation rule. The activation volume is found to decrease with increasing temperature for dislocation nucleation creep, which agrees well with experimental results. The study opens up an avenue for quantitatively discussing the entropic effects on various thermally activated deformations in nanocrystals.
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- 2013
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49. Atomistic Design of High Strength Crystalline-Amorphous Nanocomposites
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Akio Ishii, Shin Yamamoto, Yun-Jiang Wang, and Shigenobu Ogata
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Toughness ,Amorphous metal ,Nanocomposite ,Materials science ,Mechanical Engineering ,Condensed Matter Physics ,Amorphous phase ,Amorphous solid ,Molecular dynamics ,Mechanics of Materials ,General Materials Science ,Composite material ,Ductility ,Nanoscopic scale - Abstract
There is a long-standing demand for materials which could simultaneously demonstrate multiple promising properties like high strength,good ductility and toughness. In this study, a three-dimensional bulk nanocomposite material which is composed of nanoscale crystalline metaland metallic glass is revealed to present high strength and potentially good ductility by molecular dynamics. A critical high strength is achievedby varying the ratio between crystalline and amorphous phase. The critical strength is revealed to be higher than that expected from the rule ofmixture. The mechanism underlying the occurrence of critical strength in the nanocomposite is elucidated by the interaction between dislocationand matrix of amorphous phase. Our concept could guide the engineers to design more advanced bulk nanostructured materials.[doi:10.2320/matertrans.MH201316](Received March 1, 2013; Accepted April 5, 2013; Published May 24, 2013)Keywords: nanocomposite, strength, ductility, molecular dynamics
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- 2013
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50. Development of a simple predictive model for decreased skeletal muscle mass in patients with compensated chronic liver disease
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Hiroki, Nishikawa, Hirayuki, Enomoto, Akio, Ishii, Yoshinori, Iwata, Yuho, Miyamoto, Noriko, Ishii, Yukihisa, Yuri, Ryo, Takata, Kunihiro, Hasegawa, Chikage, Nakano, Takashi, Nishimura, Kazunori, Yoh, Nobuhiro, Aizawa, Yoshiyuki, Sakai, Naoto, Ikeda, Tomoyuki, Takashima, Hiroko, Iijima, and Shuhei, Nishiguchi
- Abstract
To develop and validate a simple predictive model using easily obtained clinical parameters to predict decreased skeletal muscle mass (DSMM) in chronic liver disease (CLD) patients (n = 652).Study subjects were divided into a training set (n = 326) and a validation set (n = 326). Decreased skeletal muscle mass was diagnosed based on skeletal muscle mass index measured by bioimpedance analysis. Variables significantly associated with DSMM were identified using univariate and multivariate analyses in the training set and used to construct a predictive formula. Receiver operating characteristic (ROC) curve analysis was carried out and the predictive model was validated in the validation set. Subgroup analyses were undertaken based on gender, age, or cirrhosis status of patients.Body mass index (BMI), age, serum albumin, and branched-chain amino acid to tyrosine ratio (BTR) were determined to be significant predictive factors for DSMM. A composite formula "BALB score" was constructed [-7.740 + (0.539 × BMI) + (-0.112 × age) + (1.358 × albumin) + (-0.264 × BTR)]. The BALB score had the best predictive characteristics among all variables in both population sets (area under the ROC curve, 0.877-0.898). Patients with DSMM were stratified into three BALB score categories (4, 0-4, and0). Subgroup analyses also showed that BALB scoring was predictive of DSMM irrespective of gender, age, or cirrhosis status. The BALB score significantly correlated with psoas muscle index on computed tomography (rThe BALB scoring system based on routinely used clinical parameters offers a convenient and non-invasive method for predicting DSMM in compensated CLD patients with high accuracy.
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- 2016
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