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Search Results: 1 - 10 of 2737 matches for " Naoyuki Yamada "
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A New Metal Tag for Highly Selective and Sensitive Analyses of Amino Acids and Dipeptides by HPLC/ICP-MS  [PDF]
Daigo Iwahata, Kazuki Nakamura, Rie Yamada, Hiroshi Miyano, Naoyuki Yamada
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2013, DOI: 10.4236/jasmi.2013.32010
Abstract:

We have developed a novel metal tag, bis(ethylenediamine)-4'-methyl-4-carboxybipyridine-ruthenium N-succinimidyl ester (ECRS) for sensitive analysis of amino acids using high performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICP-MS). ECRS is a functional reagent, containing an ester group at one end that can be activated to bind to amino group and a chelated ruthenium at the other. The activated ester was reacted briefly with amino groups under weakly alkaline conditions. The ruthenium was detected sensitively by ICP-MS. ECRS was reacted with 17 proteinogenic amino acids in borate buffer. The derivatives were separated by reversed phase HPLC and identified by quadrupole-based ICP-MS. ECRS was suitable for speciation; low molecular weight compounds containing amino groups. We have thus established a quantitative analytical method for amino acids and dipeptides. The detection limits of branched amino acids (signal-to-noise ratio of 3) were 1.5 nmol·L-1 in the standard solution (100 amol per injection).

A Simple Stabilization Method of Reduced Albumin in Blood and Plasma for the Reduced/Oxidized Albumin Ratio Measurement
Kazuyuki Kubota,Naoyuki Yamada,Ei-ichiro Suzuki,Akira Nakayama
International Journal of Biomedical Science , 2009,
Abstract: Albumin (Alb) is mixture of reduced and oxidized forms. It is physiologically significant to determine Alb(red)%, which is the proportion of reduced Alb in the sum of Alb. However, reduced Alb in both blood and plasma samples is easily converted to oxidized Alb. Accordingly, the stabilization of Alb in samples is necessary to determine precise Alb(red)% values.Alb stabilization in blood or plasma was achieved by pH control and buffer dilution. At least a 50-fold dilution with 50 mmol/l phosphate buffer (pH 6.0) was required for human plasma. For human blood, a 10-fold dilution with 0.5 mol/l sodium citrate buffer (pH 4.3) was required. To measure Alb(red)%, treated samples were applied to HPLC or LC-ESI-TOFMS. We also developed a “pre-incubation method”, to accelerate the oxidative reaction in plasma by heating at 37°C. Alb(red)% values were maintained around the initial value for 48 h after stabilizing human plasma and 72 h after stabilizing human blood. Accelerating the oxidative reaction in plasma produced large differences in the Alb(red)% values between normal and model disease samples. Precise Alb(red)% values were routinely obtained under the stabilization control. Additionally, pre-incubation of the plasma before measurement is useful to enhance the difference between normal and disease samples
Persistence of Structural Changes at the Anterior Cornea in Bullous Keratopathy Patients after Endothelial Keratoplasty
Naoyuki Morishige, Naoyuki Yamada, Yukiko Morita, Kazuhiro Kimura, Koh-Hei Sonoda
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0074279
Abstract: Subepithelial fibrosis (SEF) and the transdifferentiation of keratocytes into fibroblasts or myofibroblasts (Fbs/MFbs) have been detected in the cornea of individuals with bullous keratopathy. We examined the anterior cornea of bullous keratopathy patients for such changes after Descemet’s stripping automated endothelial keratoplasty (DSAEK). Twenty-two individuals who underwent unilateral DSAEK at Yamaguchi University Hospital were enrolled in the study. The subjects were divided into groups A (n = 10) and B (n = 12) with a preoperative duration of stromal edema of less than or at least 12 months, respectively. The structure of the anterior stroma was examined by in vivo laser confocal microscopy at various times after surgery. SEF was detected in 1 (10.0%) and 11 (91.7%) cases in groups A and B, respectively, before surgery as well as in 0 (0%) and 7 (58.3%) cases, respectively, at 6 months after DSAEK. Fb/MFb transdifferentiation was detected in 0 (0%) and 8 (66.7%) cases in groups A and B, respectively, before surgery as well as in 0 and 1 (8.3%) case, respectively, at 6 months postsurgery. Anterior stromal scattering (ASS) was detected in 10 (100%) and 12 (100%) cases in groups A and B, respectively, before surgery as well as in 0 (0%) and 6 (50.0%) cases, respectively, at 6 months after DSAEK. Changes in anterior stromal structure apparent before surgery were thus also detected in bullous keratopathy patients after DSAEK. SEF and ASS persisted for more than 6 months in a substantial proportion of individuals with a preoperative duration of stromal edema of at least 12 months.
Intrinsic Properties of AFe2As2 (A = Ba, Sr) Single Crystal under Highly Hydrostatic Pressure Conditions
Kazuyuki Matsubayashi,Naoyuki Katayama,Kenya Ohgushi,Atsushi Yamada,Kouji Munakata,Takehiko Matsumoto,Yoshiya Uwatoko
Physics , 2009, DOI: 10.1143/JPSJ.78.073706
Abstract: We measured the electrical resistivity and ac magnetic susceptibility of BaFe2As2 and SrFe2As2 single crystals under pressure using a cubic anvil apparatus. For BaFe2As2, the antiferromagnetic (AF) and structural transitions are suppressed with increasing pressure. Unexpectedly, these transitions persist up to 8 GPa, and no signature of a superconducting transition was observed in the pressure range investigated here. On the other hand, the AF and structural transitions of SrFe2As2 collapse at around the critical pressure Pc ~ 5 GPa, resulting in the appearance of bulk superconductivity. The superconducting volume fraction abruptly increases above Pc, and shows a dome centered at approximately 6 GPa. Our results suggest that the bulk superconducting phase competes with the AF/orthorhombic phase and only appears in the narrow pressure region of the tetragonal phase.
RETRACTED: Endotoxin Occurrence in Raw and Reclaimed Wastewater  [PDF]
Guizani Mokhtar, Funamizu Naoyuki
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.67066
Abstract:

Short Retraction Notice


The paper does not meet the standards of \"Journal of Water Resource and Protection\".


This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.


Editor guiding this retraction: Prof. Dr. Jian Shen (EiC of JWARP).


The full retraction notice in PDF is preceding the original paper which is marked \"RETRACTED\".

The Globular Cluster System of NGC 4636 and Formation of Globular Clusters in Giant Elliptical Galaxies
Hong Soo Park,Myung Gyoon Lee,Ho Seong Hwang,Sang Chul Kim,Nobuo Arimoto,Yoshihiko Yamada,Naoyuki Tamura,Masato Onodera
Physics , 2012, DOI: 10.1088/0004-637X/759/2/116
Abstract: We present a spectroscopic analysis of the metallicities, ages, and alpha-elements of the globular clusters (GCs) in the giant elliptical galaxy (gE) NGC 4636 in the Virgo cluster. Line indices of the GCs are measured from the integrated spectra obtained with Faint Object Camera and Spectrograph (FOCAS) on the Subaru 8.2 m telescope. We derive [Fe/H] values of 59 GCs based on the Brodie & Huchra method, and [Z/H], age, and [a/Fe] values of 33 GCs from the comparison of the Lick line indices with single stellar population models. The metallicity distribution of NGC 4636 GCs shows a hint of a bimodality with two peaks at [Fe/H]=-1.23 (sigma=0.32) and -0.35 (sigma=0.19). The age spread is large from 2 Gyr to 15 Gyr and the fraction of young GCs with age < 5 Gyr is about 27%. The [a/Fe] of the GCs shows a broad distribution with a mean value [a/Fe]~0.14 dex. The dependence of these chemical properties on the galactocentric radius is weak. We also derive the metallicities, ages, and [a/Fe] values for the GCs in other nearby gEs (M87, M49, M60, NGC 5128, NGC 1399, and NGC 1407) from the line index data in the literature using the same methods as used for NGC 4636 GCs. The metallicity distribution of GCs in the combined sample of seven gEs including NGC 4636 is found to be bimodal, supported by the KMM test with a significance level of >99.9%. All these gEs harbor some young GCs with ages less than 5 Gyr. The mean age of the metal-rich GCs ([Fe/H] > -0.9) is about 3 Gyr younger than that of the metal-poor GCs. The mean value of [a/Fe] of the gE GCs is smaller than that of the Milky Way GCs. We discuss these results in the context of GC formation in gEs.
Some Comments on the Real Meaning of Schrodinger’s Equation Revealed by the Fact that Electron Is Always a Particle  [PDF]
Hironari Yamada
Journal of Quantum Information Science (JQIS) , 2012, DOI: 10.4236/jqis.2012.24017
Abstract:

We all physicist have long been believed that an elementary particle is a wave as well as a particle, but we discuss in this paper that an electron (probably all fermions) is always a particle. Author claim that quantum mechanics (QM) is not such mysterious as Bohr stated that the wave turn to the particle by observation. We can understand QM by natural human sense. The wave nature of electrons is only an appearance or a phenomena but not intrinsic or substantial. An electron is an individual body, which interferes with other individual electrons. Interference is the key word instead of the wave to understand the quantum mechanics. Interference produces the wave nature and the uncertainty. When we determine that an electron is nothing but a particle, we will see the true meaning of wave function and the Schr?dinger’s equation.

Single Exposure to Antidepressants during Infancy Is Associated with Delayed Behavioral Changes in C57BL/6 Mice  [PDF]
Kazuyuki Yamada
World Journal of Neuroscience (WJNS) , 2016, DOI: 10.4236/wjns.2016.62019
Abstract: As serotoninergic transmission plays a crucial role in higher brain function in mammals, the disturbance of this system will likely have significant effects on emotion and cognition. Previous studies have reported that chronic treatment with Specific Serotonin Reuptake Inhibitors (SSRIs) during both late pregnancy and lactation was associated with abnormal behavior in adult rats. These data imply that disturbances in serotoninergic transmission during neurodevelopment may have negative effects on both the structure and function of the resultant adult brain. Therefore, the effect of a single exposure to an SSRI or a tricyclic antidepressant that preferentially inhibits serotonin reuptake during the pre-weaning period was examined in adult mice. An oral infusion of paroxetine (70 mg/kg), fluvoxamine (250 mg/kg), clomipramine (180 mg/kg), or saline was administered on postnatal day 14. Starting at 11 weeks of age, mice were assessed using a comprehensive behavioral test battery. Mice treated with paroxetine demonstrated altered behavior on the open field and hole-board tasks; those treated with fluvoxamine had behavioral changes on the light-dark box, hole-board, and sucrose preference tasks, while alteration in forced swimming and cued fear behavior were noted in mice treated with clomipramine. These results suggest that even a single administration of an antidepressant could have profound effects on behavior in adulthood, although the effects might differ dependent on the specific drug that was administered.
Stromal micropapillary component as a novel unfavorable prognostic factor of lung adenocarcinoma
Miki Ohe, Tomoyuki Yokose, Yuji Sakuma, Yohei Miyagi, Naoyuki Okamoto, Sachie Osanai, Chikako Hasegawa, Haruhiko Nakayama, Yoichi Kameda, Kouzo Yamada, Takeshi Isobe
Diagnostic Pathology , 2012, DOI: 10.1186/1746-1596-7-3
Abstract: We investigated the clinicopathological characteristics and prognostic significance of SMPC in lung adenocarcinoma cases by reviewing 559 patients who had undergone surgical resection. We examined the SMPC by performing immunohistochemical analysis with 17 antibodies and by genetic analysis with epidermal growth factor receptor (EGFR) and KRAS mutations.SMPC-positive (SMPC(+)) tumors were observed in 19 cases (3.4%). The presence of SMPC was significantly associated with tumor size, advanced-stage disease, lymph node metastasis, pleural invasion, lymphatic invasion, and vascular invasion. Patients with SMPC(+) tumors had significantly poorer outcomes than those with SMPC-negative tumors. Multivariate analysis revealed that SMPC was a significant independent prognostic factor of lung adenocarcinoma, especially for disease-free survival of pathological stage I patients (p = 0.035). SMPC showed significantly higher expression of E-cadherin and lower expression of CD44 than the corresponding expression levels shown by AMPC and showed lower surfactant apoprotein A and phospho-c-Met expression level than corresponding expression levels shown by tumor cell components without a micropapillary component. Fourteen cases with SMPC(+) tumors (74%) showed EGFR mutations, and none of them showed KRAS mutations.SMPC(+) tumors are rare, but they may be associated with a poor prognosis and have different phenotypic and genotypic characteristics from those of AMPC(+) tumors.The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9433341526290040 webcite.A new lung adenocarcinoma classification system has been proposed by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) [1]. In this classification, the micropapillary component (MPC) was recommended as a new subtype of lung adenocarcinoma in addition to the lepidic, acinar, papillary, and solid subtypes
The local atomic structure of superconducting Fe-Se-Te
Martin C. Lehman,Despina Louca,Kazumasa Horigane,Anna Llobet,Ryotaro Arita,Sungdae Ji,Naoyuki Katayama,Shun Konbu,Kazuma Nakamura,Peng Tong,Tae-Yeong Koo,Kazuyoshi Yamada
Physics , 2009,
Abstract: We report on the first local atomic structure study via the pair density function (PDF) analysis of neutron diffraction data and show a direct correlation of local coordinates to TC in the newly discovered superconducting FeSe1-xTex. The isovalent substitution of Te for Se such as in FeSe0.5Te0.5 increases Tc by twofold in comparison to a-FeSe without changing the carrier concentration but, on average, decreases the chalcogen-Fe bond angle. However, we find that the local symmetry is lower than the average P4/nmm crystal symmetry, because the Se and Te ions do not share the same site, leading to two distinct z-coordinates that exhibit two types of bond angles with Fe. The angle indeed increases from ~ 104.02o in FeSe to ~105.20o in FeSe0.5Te0.5 between Fe and Se. Simultaneously, ab-initio calculations based on spin density function theory yielded an optimized structure with distinct z-coordinates for Se and Te, in agreement with the experiment. The valence charge distribution in the Fe-Se bonds was found to be different from that in the Fe-Te bonds. Thus, superconductivity in this chalcogenide is closely related to the local structural environment, with direct implications on the multiband magnetism where modulations of the ionic lattice can change the distribution of valence electrons.
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