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Photocatalytic dry reforming of methane by rhodium supported monoclinic TiO_(2)-B nanobelts

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Journal of Energy Chemistry 2022年第8期31卷 562-571,I0015页

作者： Masaru Kushida akira Yamaguchi Masahiro Miyauchi School of Materials and Chemical Technology Tokyo Institute of Technology2-12-1 OokayamaMeguro-kuTokyo 152-8552Japan

The conversion of methane and carbon dioxide into syngas(dry reforming of methane;DRM)has attracted attention owing to the potential to reuse greenhouse *** dioxide(TiO_(2))-based photocatalysts,which have been widely commercialized owing to their high efficiency,non-toxicity,and low cost,are strongly desired in ***,we report a monoclinic-phase TiO_(2)-B nanobelts-supported rhodium(Rh/TiO_(2)-B nanobelts)catalyst that efficiently promotes DRM under ultraviolet light irradiation at low *** holes in the TiO_(2)-B nanobelts were used to oxidize methane,while the electrons were trapped in rhodium to reduce carbon ***/TiO_(2)-B nanobelts exhibited considerably higher durability and activity than Rh-loaded conventional TiO_(2)(anatase and rutile),owing to the lattice and/or surface oxygen reactivity in TiO_(2)-B nanobelts,which was suggested by X-ray photoelectron spectroscopy measurements and photocatalytic performance tests under an atmosphere of methane *** study paves the path for the effective utilization of methane by constructing active TiO_(2)-based nanometal photocatalysts.

关键词： Photocatalysis Dry reforming of methane Greenhouse gas conversion Gas-phase reaction Titanium dioxide TiO_(2)-B

Growth phase dependent changes in the structure and protein composition of nucleoid in Escherichia coli

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Science China(Life Sciences) 2015年第9期58卷 902-911页

作者： TALUKDER AliAzam ISHIHAMA akira Department of Microbiology Jahangirnagar University Micro-Nano Technology Research Center Hosei University Department of Molecular Genetics National Institute of Genetics

The genomic DNA of bacteria is highly compacted in a single or a few bodies known as nucleoids. Here, we have isolated Escherichia coli nucleoid by sucrose density gradient centrifugation. The sedimentation rates, structures as well as pro- tein/DNA composition of isolated nucleoids were then compared under various growth phases. The nucleoid structures were found to undergo changes during the cell growth; i. e., the nucleoid structure in the stationary phase was more tightly com- pacted than that in the exponential phase. In addition to factor for inversion stimulation （Fis）, histone-like nucleoid structuring protein （H-NS）, heat-unstable nucleoid protein （HU） and integration host factor （IHF） here we have identified, three new can- didates of E. coli nucleoid, namely DNA-binding protein from starved cells （Dps）, host factor for phage QJ3 （Hfq） and sup- pressor of taC phenotype A （StpA）. Our results reveal that the major components of exponential phase nucleoid are Fis, HU, H-NS, StpA and Hfq, while Dps occupies more than half of the stationary phase nucleoid. It has been known for a while that Dps is the main nucleoid-associated protein at stationary phase. From these results and the prevailing information, we propose a model for growth phase dependent changes in the structure and protein composition of nucleoid in E. coli.

关键词： growth phase sucrose gradient bacterial nucleoid DNA binding protein DNA compaction

Surface Texturing of TiO_2 Film by Mist Deposition of TiO_2 Nanoparticles

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Nano-Micro Letters 2013年第2期5卷 129-134页

作者： Gang Qin akira Watanabe Institute of Multidisciplinary Research for Advanced Materials Tohoku University School of Materials Science and Engineering Henan Polytechnic University

Unique and various microstructures of titanium oxide(TiO_2 ) film including macroporous structure, chromatic veins and rings, have been easily fabricated by mist deposition method on silicon substrate with mild preparation conditions. Rutile phase TiO_2 nanoparticles were directly used as starting material to prepare film and led to a simple preparation process. It was found that several different microstructures existed in the sample and changed with the varied positions from the center to the edge of the film when the concentration of the TiO_2 suspension is 0.06 mol/l, the deposition time is 30 min, the flow rate is 1 l/min and the temperature is150. The surface texturing shows apparent distinction as the concentration of the TiO_2 suspension decreased to 0.03 mol/l and 0.01 mol/l.

关键词： Mist deposition TiO2 film TiO2 nanoparticle Surface texturing Microstructure

Dynamic distribution of TTK in HeLa cells: insights from an ultrastructural study

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Cell Research 2003年第6期13卷 443-449页

作者： akira SAWAGECHI,LAWRENCE BRAKO Department of Molecular and Cell Biology University of California Berkeley CA 94720 USA Electron Microscopy Facility Morhouse School of Medicine Atlanta GA 30310 USA

Entry into mitosis is driven by signaling cascades of mitotic kinases. Our recent studies show that TTK, a kinetochore-associated protein kinase, interacts with CENP-E, a mitotic kinesin located to corona fiber of kinetochore. Using immunoelectron microscopy, here we show that TTK is present at the nuclear pore adjacent complex of interphase HeLa cells. Upon nuclear envelope fragmentation, TTK targets to the outermost region of the developing kinetochores of monoorient chromosome as well as to spindle poles. After stable attachment, throughout chromosome congression, TTK is a constituent of the corona fibers, extending up to 90 nm away from the kinetochore outer plate. Upon metaphase alignment, TTK departs from the kinetochore and migrates toward the centrosomes. Taken together, this evidence strongly supports a model in which TTK functions in spindle checkpoint signaling cascades at both kinetochore and centrosome.

关键词： mitosis kinetochore TTK.

Next-generation research on transcriptional regulation of plant immunity

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Molecular Plant 2024年第11期17卷 1651-1653页

作者： akira Mine Laboratory of Plant Pathology Graduate School of AgricultureKyoto UniversityKyoto 606-8502Japan

Plant health is fundamental for agricultural production to feed the growing global population as well as for primary production to sustain ecosystem *** innate immune system of plants is integral to their health;it is activated upon recognition of pathogen invasion by immune receptors,leading to pathogen resistance through genome-wide transcriptional *** defense-associated transcriptome reprogramming is mediated by various immune signals,including the phytohormone salicylic acid(SA).SA plays a pivotal role in activating pathogen resistance both locally in infected tissues and systemically in uninfected *** Arabidopsis thaliana,SA is perceived by its receptors NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1(NPR1),NPR3,and *** NPR3 and NPR4 function as negative regulators of SA signaling,NPR1 serves as a key positive regulator of SA-mediated transcriptomic changes and pathogen resistance(Ding et al.,2018).Consistent with its lack of a DNA-binding domain,NPR1 has been shown to act as a transcription cofactor for multiple transcription factors(TFs)such as TGAs and WRKYs(Wang et al.,2006;Kumar et al.,2022).Besides TFs,other components of the transcriptional machinery are likely to participate in NPR1-regulated transcriptional responses,as NPR1 forms nuclear condensates upon SA induction(Zavaliev et al.,2020).Despite decades of research on NPR1’s functions in plant immunity,a comprehensive understanding of how NPR1 cooperates with multiple TFs and other components of the transcriptional machinery to initiate and propagate transcriptional responses to SA is still lacking.

关键词： transcriptional plant immunity

Functionally Graded Dual-nanoparticulate-reinforced Aluminium Matrix Bulk Materials Fabricated by Spark Plasma Sintering

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Journal of Materials Science & Technology 2014年第8期30卷 736-742页

作者： Hansang Kwon Marc Leparoux akira Kawasaki Department of Materials System Engineering Pukyong National University365 Sinsenro608-759 BusanKorea Empa Swiss Federal Laboratories for Materials Science and TechnologyAdvanced Materials ProcessingFeuerwerkerstrasse 39CH-3602 ThunSwitzerland Department of Materials Processing Engineering Graduate School of EngineeringTohoku University980-8579 SendaiJapan

Functionally graded（FG） carbon nanotubes（CNT） and nano-silicon carbide（nSiC） reinforced aluminium（Al）matrix composites have been successfully fabricated using high-energy ball milling followed by solid-state spark plasma sintering *** CNTs were well-dispersed in the Al particles using the nSiC as a solid mixing *** different types of multi-walled CNTs were used to add different amounts of CNTs in the same *** ball milled Al—CNT—nSiC and Al—CNT powder mixtures were fully densified and demonstrated good adhesion with no serious microcracks and pores within an FG multilayer *** layer contained different amounts of the CNTs,and the nSiC additions showed different microstructures and *** is possible to control the characteristics of the FG multilayer composite through the efficient design of an Al—CNT—nSiC gradient *** concept offers a feasible approach for fabricating the dualnanoparticulate-reinforced Al matrix nanocomposites and can be applied to other scenarios such as polymer and ceramic systems.

关键词： Carbon nanotubes(CNT) Silicon carbide High-energy ball milling Spark plasma sintering(SPS) Functionally graded materials(FGM)

Activities of nicotinic acetylcholine receptors modulate neurotransmission and synaptic architecture

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Neural Regeneration Research 2014年第24期9卷 2128-2131页

作者： akira Oda Hidekazu Tanaka CNS Drug Discovery Unit Pharmaceutical Research Division Takeda Pharmaceutical Company Limited Laboratory of Pharmacology Department of Biomedical Sciences College of Life Sciences Ritsumeikan University

The cholinergic system is involved in a broad spectrum of brain function, and its failure has been implicated in Alzheimer＇s disease. Acetylcholine transduces signals through muscarinic and nicotinic acetylcholine receptors, both of which influence synaptic plasticity and cognition. However, the mechanisms that relate the rapid gating of nicotinic acetylcholine receptors to persistent changes in brain function have remained elusive. Recent evidence indicates that nicotinic acetylcholine receptors activities affect synaptic morphology and density, which result in persistent rearrangements of neural connectivity. Further investigations of the relationships between nicotinic acetylcholine receptors and rearrangements of neural circuitry in the central nervous system may help understand the pathogenesis of Alzheimer＇s disease.

关键词： cholinergic system nicotinic acetylcholine receptors (nAChRs) Alzheimer's disease (AD) synaptic transmission synaptic plasticity synaptic morphology dendritic spine remodeling cognition

Optimization of the gain in Yb^(3+)-doped cubic laser crystals of 99.99% purity

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Journal of Rare Earths 2009年第4期27卷 616-618页

作者： Georges Boulon Yannick Guyot akira Yoshikawa Physical Chemistry of Luminescent Materials University Claude Berna rd/Lyon1 UMR 5620 CNRS Bt.A.Kastler Domaine Scientifique de La Doua 69622 Villeurbanne France IMRAM Tohoku University 2-1-1 Katahira Aoba-ku Sendai 980-8577 Japan

This was an outlook on the prediction of the infrared laser potentiality from concentration dependences of the 2F5/2 experimental decay time in Yb3＋-doped solid-state crystals mainly on cubic crystals with 99.99% pur... 详细信息

关键词： ytterbium fluoride garnet sesquioxide laser crystals concentration quenching self trapping lifetime

Luminescence of Er^(3+) in Oxyfluoride Transparent Glass-Ceramics

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Journal of Rare Earths 2006年第6期24卷 699-705页

作者： akira Ueda Steven H Morgan Richard Mu Department of Physics Fisk University NashvilleTN 37208 USA

Erbium doped silicate, germanate, and tellurium-germanate oxyfluoride glasses were prepared in a bulk form. Through appropriate heat treatment of the as-prepared glasses, transparent glass-ceramics （TGCs） were obtained with the formation of β-PbF2：Er^3＋ nanocrystals in the glass matrix were confirmed by X-ray ***-defined diffraction peaks were observed in the samples after heat-treatment. The average crystal diameter of these precipitated crystals from full-width at half-maximum （FWHM） of the diffraction peak was estimated to be between 8 and 13 nm. Optical absorption, photoluminescence, and upconversion luminescence were measured on as-prepared glass and glass-ceramics. Luminescence spectra in the TGC samples revealed well-resolved, sharp stark-splitting peaks, which indicates that a majority of Er^3＋ ions has been incorporated into the crystalline phase of the nanocrystals. The intensity of the visible and near infrared luminescence mostly increases in TSG compared to that in the as-prepared glass. In 1.53 μm absorption and emission bands, the maximum absorption peak is blue-shifted from 1531 to 1507 nm, whereas the maximum emission peak is redshifted from 1535 to 1543 nm in TGC, as compared with that in glass. The bandwidth at half-maximum （BWHM） of the emission band is significantly broader in TGC than in glass, which is beneficial to the erbium-doped fiber amplifier （EDFA）. Upconversion luminescence was measured using 800 nm near-infrared light excitation. Drastically increased upconversion 1 was observed from the TGC as compared to that from their corresponding as-prepared glasses. In addition to a strong green emission centered at 545 nm because of ^4S3/2→^4I15/2 transition and a weaker red emission centered at 662 nm because of ^4F9/2→^4I15/2 transition, generally seen from the Er^3＋ doped glasses, two violet emissions centered at 410 nm because of ^2H9/2→^4I15/2 transition and centered at 379 nm because of ^4G11/2→^4I15/2 transition were also o

关键词： luminescence transparent glass-ceramics rare earths