370 results match your criteria: "Tsukuba Research Center[Affiliation]"

We describe here the preparation of soft crystals using disilanyl macrocycle possessing four -phenylenes circularly connected by four flexible disilane bonds. Single crystals of exhibited a reversible thermal single-crystal-to-single-crystal (SCSC) phase transition behavior between two crystal phases accompanied by remarkable mechanical motion (thermosalient effect), as revealed by thermal analyses and X-ray diffraction measurements. Detailed structural analyses implied that flexibility of the parallelogram disilanyl architecture and molecular packing mode via weak intermolecular interactions facilitated a concerted structural transformation (parallel crank motion) of macrocycles in the crystal, thus resulting in the SCSC phase transition accompanied by anisotropic shrinking/elongation of the cells to induce the thermosalient effect.

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Miniaturized terahertz-driven electron accelerator.

Front Optoelectron

June 2020

Tsukuba Research Center for Interdisciplinary Materials Science, University of Tsukuba, Tsukuba, Ibaraki, 305-8573, Japan.

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Single-Crystalline Optical Microcavities from Luminescent Dendrimers.

Angew Chem Int Ed Engl

July 2020

Department of Materials Science, Faculty of Pure and Applied Sciences, and, Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.

Microcrystallites are promising minute mirrorless laser sources. A variety of luminescent organic compounds have been exploited along this line, but dendrimers have been inapplicable owing to their fragility and extremely poor crystallinity. Now, a dendrimer family that overcomes these difficulties is presented.

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Characterisation of the temperature-dependent M to R phase transition in W-doped VO nanorod aggregates by Rietveld refinement and theoretical modelling.

Phys Chem Chem Phys

April 2020

Guangxi Key Laboratory of Information Material, Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, 541004, P. R. China. and Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587, Japan.

Article Synopsis
  • Understanding the insulator-metal transition (IMT) in VO2 is crucial for enhancing its material properties for various applications.
  • Researchers utilized Rietveld refinement on X-ray diffraction data of V1-xWxO2 nanorods to study how doping affects the structure and properties of both the insulating and metallic phases across different temperatures.
  • Their findings indicate that increasing W doping leads to lower transition temperatures due to changes in the dimer structure and band gap, offering insights into the physical mechanisms of the IMT and guidance for optimizing VO2-based materials.
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Background: Platelets play a pivotal role in hemostasis, wound healing, and inflammation, and are thus implicated in a variety of diseases, including cancer. Platelet function is associated with release of granule content, cellular shape change, and upregulation of receptors that promote establishment of a thrombus and maintenance of hemostasis.

Objectives: The role of heat shock proteins (Hsps) in modulating platelet function has been studied for a number of years, but comparative roles of individual Hsps have not been thoroughly examined.

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Energy harvesting thermocell with use of phase transition.

Sci Rep

February 2020

Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8571, Japan.

A thermocell that consists of cathode and anode materials with different temperature coefficients (α = dV/dT) of the redox potential (V) can convert environmental thermal energy to electric energy via the so-called thermal charging effect. The output voltage V of the current thermocell, however, is still low (several tens mV) and depends on temperature, which are serious drawbacks for practical use of the device as an independent power supply. Here, we report that usage of phase transition material as electrode qualitatively improve the device performance.

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At present, copper sulfide materials have been predicted as promising thermoelectric materials due to their inexpensiveness and nontoxicity property. Most researches on copper sulfide are focused on CuS and CuS because they are more easily synthesized into a single phase; however, the improper electrical conductivity greatly hindered their thermoelectric properties. In this work, a series of high-performance CuNiS ( = 0, 0.

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Ascophyllan HS is a commercially available preparation of the edible brown alga Ascophyllum nodosum containing ascophyllan, a sulfated polysaccharide with diverse beneficial biological activities. In this study, the effects of ascophyllan HS were evaluated in a severe intranasal Streptococcus pneumoniae infection mouse model. The control untreated mice started to die on day 7 and 80% had died by day 14 post-infection.

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Hydrogen boride nanosheets (HB sheets) are facilely synthesized via ion-exchange treatment on magnesium diboride (MgB) in an acetonitrile solution. Optical absorption and fluorescence spectra of HB sheets indicate that their bandgap energy is 2.8 eV.

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Hemozoin produced by mammals confers heme tolerance.

Elife

October 2019

Department of Animal and Avian Sciences, University of Maryland, College Park, United States.

Free heme is cytotoxic as exemplified by hemolytic diseases and genetic deficiencies in heme recycling and detoxifying pathways. Thus, intracellular accumulation of heme has not been observed in mammalian cells to date. Here we show that mice deficient for the heme transporter SLC48A1 (also known as HRG1) accumulate over ten-fold excess heme in reticuloendothelial macrophage lysosomes that are 10 to 100 times larger than normal.

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The photoisomerization of molecules is widely used to control the structure of soft matter in both natural and synthetic systems. However, the structural dynamics of the molecules during isomerization and their subsequent response are difficult to elucidate due to their complex and ultrafast nature. Herein, we describe the ultrafast formation of higher-orientation of liquid-crystalline (LC) azobenzene molecules via linearly polarized ultraviolet light (UV) using ultrafast time-resolved electron diffraction.

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Hydrogenated Borophene Shows Catalytic Activity as Solid Acid.

ACS Omega

August 2019

Graduate School of Pure and Applied Sciences, Department of Materials Science, Faculty of Pure and Applied Sciences, and Tsukuba Research Center for Energy Materials Science, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573, Japan.

Hydrogen boride (HB) or hydrogenated borophene sheets are recently realized two-dimensional materials that are composed of only two light elements, boron and hydrogen. However, their catalytic activity has not been experimentally analyzed. Herein, we report the catalytic activity of HB sheets in ethanol reforming.

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Highly oriented, multilayer molecular films of picene and dinaphtho[2,3-:2',3'-]thieno[3,2-]thiophene (DNTT) molecules with the long axis parallel to the substrate (parallel configuration, hereafter) were fabricated on their characteristic bulklike monolayer. These molecules form a dense monolayer with a bulklike molecular arrangement on metal surfaces such as Au(111), which allows further stacking of parallel molecules. Indeed, upon adsorption of picene and DNTT on these dense monolayers, growth of straight islands of multilayer without the dendritic layer was observed.

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CYP3A4 Induction in the Liver and Intestine of Pregnane X Receptor/CYP3A-Humanized Mice: Approaches by Mass Spectrometry Imaging and Portal Blood Analysis.

Mol Pharmacol

November 2019

Laboratory of DDS Design and Drug Disposition, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba (K.K., G.M.); Discovery Drug Metabolism & Pharmacokinetics, Tsukuba Research Center, Taiho Pharmaceutical Co., Ltd., Ibaraki (J.Ku.); Chromosome Engineering Research Center (CERC), Tottori University, Tottori (S.A., S.T., M.O., Y.K.); Laboratory of Biofunctional Science, School of Pharmacy and Pharmaceutical Sciences, Hoshi University, Tokyo (K.I.); Division of Cellular and Molecular Toxicology, Biological Safety Research Center, National Institutes of Health Sciences, Kanagawa (S.K., J.Ka.); Japan Bioassay Research Center, Japan Organization of Occupational Health and Safety, Kanagawa (J.Ka.); Analytical & Measuring Instruments Division, Shimadzu Corporation, Kyoto (T.Y.); and Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Tottori (Y.K.), Japan

Induction of cytochrome P450 enzyme 3A (CYP3A) in response to pregnane X receptor (PXR) activators shows species-specific differences. To study the induction of human CYP3A in response to human PXR activators, we generated a double-humanized mouse model of PXR and CYP3A. CYP3A-humanized mice generated by using a mouse artificial chromosome (MAC) vector containing the entire genomic human CYP3A locus (hCYP3A-MAC mouse line) were bred with PXR-humanized mice in which the ligand-binding domain of mouse PXR was replaced with that of human PXR, resulting in double-humanized mice (hCYP3A-MAC/hPXR mouse line).

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A two-dimensional nanocarbon, graphene, has attracted substantial interest due to its excellent properties. The reduction of graphene oxide (GO) has been investigated for the mass production of graphene used in practical applications. Different reduction processes produce different properties in graphene, affecting the performance of the final materials or devices.

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A low band-gap polymer, PTB7-Th, is one of the typical p-type semiconductors among the next-generation solar-cell materials that have achieved power conversion efficiencies of over 10%. However, the internal deterioration mechanism of high-efficiency polymer solar cells such as PTB7-Th-based cells is still an open issue and has been extensively studied. Here, we report a study with operando electron spin resonance (ESR) spectroscopy for PTB7-Th polymer solar cells with an n-type semiconductor PCBM to clarify the internal deterioration mechanism at a molecular level.

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Efficient luminescent properties and cation recognition ability of heavy group 13 element complexes of NO- and NO-type dipyrrins.

Dalton Trans

September 2019

Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.

The first mononuclear 1 : 1 complexes of heavy group 13 elements (Ga and In) and NO/NO-type dipyrrins were synthesized and characterized. The NO-type complexes showed efficient luminescent properties even in polar solvents. The NO-type complexes exhibited fluorometric responses to alkaline earth metal ions.

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Understanding gas-surface reaction dynamics, such as the rupture and formation of bonds in vibrationally and translationally excited ('hot') molecules, is important to provide mechanistic insight into heterogeneous catalytic processes. Although it has been established that such excitation can affect the reactions occurring via dissociative mechanisms, for associative mechanisms-in which the gas-phase reactant collides directly with a surface-adsorbed species-only translational excitation has been observed to affect reactivity. Here we report a bond-formation reaction that is driven by the vibrational energy of reactant molecules and occurs via an (associative) Eley-Rideal-type mechanism, in which the reaction takes place in a single collision.

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Bpytrisalen/Bpytrisaloph: A Triangular Platform That Spatially Arranges Different Multiple Labile Coordination Sites.

Inorg Chem

June 2019

Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) , University of Tsukuba, 1-1-1 Tennodai , Tsukuba , Ibaraki 305-8571 , Japan.

Complexes that possess multiple metals in their proximity exert useful functions such as multivalent capture and catalytic activities. However, it is often challenging to arrange multiple metals with regular distances and to maintain the reactive coordination sites. We have now designed and synthesized organic macrocyclic ligands, bpytrisalen and bpytrisaloph, as platforms to spatially arrange different kinds of metals and their coordination sites.

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The first porous molecular conductor (PMC), which exhibits porosity, a through-space conduction pathway and rich charge carriers (electrons), was prepared through electrocrystallization from Cd and N, N'-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxdiimide (NDI-py). [Cd(NDI-py)(OH)](NO)· nDMA (PMC-1) was assembled by π-π stacking among one-dimensional (1D) linear coordination polymers. The NDI cores were partially reduced into radical anions to form conductive π-stacked columns, yielding (1.

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Double-Circularly Connected Saloph-Belt Macrocycles Generated from a Bis-Armed Bifunctional Monomer.

J Am Chem Soc

April 2019

Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) , University of Tsukuba, 1-1-1 Tennodai , Tsukuba , Ibaraki 305-8571 , Japan.

Belt-shaped macrocycles possessing saloph units as their walls have been generated by the double-circular connection of a bis-armed bifunctional monomer bearing both o-phenylenediamine and salicylaldehyde functionalities. The saloph-belt macrocycles showed unique properties, such as the selective inclusion of fullerenes ( K(C)/ K(C) > 100), utilizing their rigid scaffolds.

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Synthesis of per(5-N-carboxamide-5-dehydroxylmethyl)-β-cyclodextrins and their selective recognition ability utilizing multiple hydrogen bonds.

Chem Commun (Camb)

April 2019

Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.

Per(5-N-carboxamide-5-dehydroxylmethyl)-β-cyclodextrin derivatives with seven equivalent amide groups directly attached to each pyranose ring were synthesized. The amide cyclodextrins show unique recognition properties toward hydrogen phosphonate anions. An X-ray crystallographic analysis revealed its recognition mode in which unsymmetrically arranged amide groups play distinctive roles both as a hydrogen bond donor and acceptor.

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A series of disilane-linked donor‒acceptor‒donor triads (D‒Si‒Si‒A‒Si‒Si‒D) was synthesized to investigate the effects of substituents on the photophysical properties. The triads were prepared by metal-catalyzed diiodosilylation of aryl iodides using a Pd(P(-Bu)₃)₂/(-Pr)₂EtN/toluene system that we previously developed. Optical measurements, X-ray diffraction analysis, and density functional theory calculations revealed relationships between the photophysical properties and molecular structures of these triads in solution and in the solid state.

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A twisted macrocyclic hexanuclear palladium complex with internal bulky coordinating ligands.

Chem Commun (Camb)

February 2019

Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.

A macrocyclic hexanuclear palladium complex, which accumulates coordination sites on metals inside the cavity, was synthesized. The macrocycle was found to take a uniquely-twisted C2-symmetric conformation when six molecules of a bulky pyridine derivative coordinated to the palladium.

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A Conformationally Flexible Macrocyclic Dipyrrin Tetramer and Its Unsymmetrically Twisted Luminescent Zinc(II) Complex.

Inorg Chem

January 2019

Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) , University of Tsukuba, 1-1-1 Tennodai , Tsukuba , Ibaraki 305-8571 , Japan.

A macrocyclic dipyrrin tetramer containing flexible m-phenylene linkages and its tetranuclear zinc(II) complex were synthesized. The obtained complex has an unsymmetrical figure-of-eight structure because of the conformational flexibility of the macrocyclic framework. The first μ-hydroxo- and μ-acetato-bridged dinuclear zinc(II) dipyrrin complex structure is realized in the twisted macrocyclic complex.

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