205 results match your criteria: "University of Tokyo 7-3-1 Hongo[Affiliation]"
Nanoscale Adv
December 2024
Department of Electrical and Electronic Engineering, Rajshahi University of Engineering & Technology Rajshahi-6204 Bangladesh
With advancements in photonic technologies, photonic crystal fibers (PCFs) have become crucial components in developing highly sensitive and efficient biosensors. This paper presents an optimized bowtie-shaped PCF biosensor that leverages surface plasmon resonance (SPR) phenomena for enhanced refractive index (RI) sensing. The proposed design uses an external sensing mechanism to effectively characterize performance across an RI range of 1.
View Article and Find Full Text PDFRSC Chem Biol
December 2024
Department of Chemistry, Graduate School of Science, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan
A chemigenetic indicator with an affinity suitable for imaging of intracellular sodium ions (Na) in mammalian cells was developed. The indicator, based on a chimera of green fluorescent protein (GFP) and HaloTag labeled with a synthetic crown ether chelator, was produced by a combination of rational design and directed evolution. In mammalian cells the indicator exhibited an approximately 100% increase in excitation ratio when the cells were treated with 20 mM Na and an ionophore.
View Article and Find Full Text PDFChem Sci
November 2024
Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan
Efrapeptin C (1a) is a large peptidic natural product comprising a 15-mer linear sequence and exerts potent anticancer activity by inhibiting mitochondrial FF-ATP synthase. Residues 1-6 and 9-15 of 1a fold into two 3-helical domains and interact with ATP synthase, while the central β-Ala-7-Gly-8 region functions as a flexible linker of the two domains. To enhance the function of 1a by minimally modifying its structure, we envisioned attaching one small methyl group to the β-Ala-7-Gly-8 and designed six methylated analogues 1b-1g, differing only in the position and configuration of the methyl group.
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November 2024
Department of Chemical System Engineering, School of Engineering, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
Manganese octahedral molecular sieves with an α-MnO crystal structure (OMS-2) and their related materials have attracted significant attention for the selective catalytic reduction of NO using NH (NH-SCR) at low temperatures. Further lowering their operating temperature should be an effective method to develop an environmentally friendly de-NO system; however, their catalytic activity at low temperatures, especially below 100 °C, remains poor. This study describes a post-synthetic approach to develop Mn-based catalysts superior to those in the literature that operate at ultralow temperatures.
View Article and Find Full Text PDFRSC Adv
October 2024
Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251 35000 Rennes France
Many rubidium manganese hexacyanoferrate materials, with the general formula Rb Mn[Fe(CN)]·HO, exhibit diverse charge-transfer-based functionalities due to the bistability between a high temperature Mn( = 5/2)Fe( = 1/2) cubic phase and a low-temperature Mn( = 2)Fe( = 0) tetragonal phase. The collective Jahn-Teller distortion on the Mn sites is responsible for the cubic-to-tetragonal ferroelastic phase transition, which is associated with the appearance of ferroelastic domains. In this study, we use X-ray diffraction to reveal the coexistence of 3 types of ferroelastic tetragonal domains and estimate the spatial extension of the strain around the domain walls, which represents about 30% of the volume of the crystal.
View Article and Find Full Text PDFChem Sci
October 2024
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo Japan.
Heteroatom-substituted ethylenes have long been studied owing to their potential application to electronic devices. In contrast to well-studied π-donor substituted ethylene, the π-acceptor substituted one has only been limitedly reported. While boron can be a candidate of π-acceptors, there has still been no example of fully conjugated tetraborylethylene (TBE).
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September 2024
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
Because of the extracellular acidic microenvironment of cancer cells, many pH-responsive molecules have become indispensable materials for bioanalysis and targeted therapy development. pH-Responsive DNA aptamers, which selectively bind to target proteins in cancer cells, have become a key research target in the therapeutic field. However, conventional pH-responsive aptamers have fatal drawbacks, such as complex structures, sequence limitation, and difficulties in mass production, as they require special nucleic acid structures, including the i-motif and DNA triplex.
View Article and Find Full Text PDFRespir Investig
November 2024
Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Background: Shoseiryuto, a Japanese herbal medicine, is used to treat asthma exacerbation; however, the effect of Shoseiryuto in a clinical setting is yet to be elucidated. We aimed to examine the effect of Shoseiryuto for inpatients with asthma exacerbation and the reduction in the total amount of intravenous steroids administered during hospitalization, in-hospital mortality, and length of hospital stay using a national inpatient database in Japan.
Methods: Using data from the Japanese Diagnosis Procedure Combination database (July 2010-March 2022), we identified patients aged ≥18 years who were admitted due to asthma exacerbation.
Nanoscale Adv
September 2024
Department of Chemistry, Institute of Science, Banaras Hindu University Varanasi India
Herein, we investigated the impact of polymorphism dimension control of titania nanocrystals towards hydrogen generation. Two different forms of titania nanoparticles have been synthesized following the solvothermal method, leading to the formation of two distinct physicochemical features. Detailed structural, morphological, and optical studies revealed that the formation of titania nanorods correspond to rutile while granular particles correspond to the anatase phase.
View Article and Find Full Text PDFChem Sci
August 2024
Department of Applied Chemistry, School of Engineering, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
Polyoxometalates (POMs), representing anionic metal-oxo clusters, display diverse properties depending on their structures, constituent elements, and countercations. These characteristics position them as promising catalysts or catalyst precursors for electrochemical carbon dioxide reduction reaction (CORR). This study synthesized various salts-TBA (tetra--butylammonium), Cs, Sr, and Ba-of a dipalladium-incorporated POM (Pd2, [γ-HSiWOPd(OAc)]) immobilized on a carbon support (Pd2/C).
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July 2024
Department of Applied Chemistry, School of Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan +81-3-5841-7220.
C-S bond metathesis of thioethers has gained attention as a new approach to the late-stage diversification of already existing useful thioethers with molecular frameworks intact. However, direct or indirect thioether metathesis is scarcely reported, and heterogeneously catalyzed systems have not been explored. Here, we develop heterogeneously catalyzed direct thioether metathesis using a supported Au-Pd alloy nanoparticle catalyst with a high Au/Pd ratio.
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July 2024
Department of Applied Chemistry, School of Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
Polyoxometalates (POMs) function as platforms for synthesizing structurally well-defined inorganic molecules with diverse structures, metals, compositions, and arrangements. Although post-editing of the oxygen sites of POMs has great potential for development of unprecedented structures, electronic states, properties, and applications, facile methods for site-selective substitution of the oxygen sites with other atoms remain limited. Herein, we report a direct site-selective oxygen-sulfur substitution method that enables transforming POMs [XWO] (X = Si, Ge) to Keggin-type polyoxothiometalates (POTMs) [XWOS] using sulfurizing reagents in an organic solvent.
View Article and Find Full Text PDFJ Phys Chem B
July 2024
Department of Bioengineering, School of Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8565, Japan.
Polymer informatics has attracted increasing attention as a specialized branch of material informatics. Hydrophilicity/hydrophobicity is one of the most important properties of interfaces involved in antifouling, self-cleaning, antifogging, oil/water separation, protein adsorption, and bioseparation. Establishing a quantitative structure-property relationship for the hydrophilicity/hydrophobicity of polymeric interfaces could significantly benefit from machine learning modeling.
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June 2024
Department of Applied Chemistry, School of Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
Self-assembly coordination bonding facilitates the creation of diverse inorganic-organic molecular hybrids with distinct structures and properties. Recent advances in this field have been driven by the versatility of organic ligands and inorganic units. Lacunary polyoxometalates are a class of well-defined metal-oxide clusters with a customizable number of reactive sites and bond directions, which make them promising inorganic units for self-assembled molecular hybrids.
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May 2024
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
Peptoids are a promising drug modality targeting disease-related proteins, but how a peptoid engages in protein binding is poorly understood. This is primarily due to a lack of high-resolution peptoid-protein complex structures and systematic physicochemical studies. Here, we present the first crystal structure of a peptoid bound to a protein, providing high-resolution structural information about how a peptoid binds to a protein.
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May 2024
Department of Materials Chemistry, Faculty of Engineering, Shinshu University 4-17-1 Wakasato Nagano 380-8553 Japan
Recombination of photoexcited carriers at interface states is generally believed to strongly govern the photoelectrochemical (PEC) performance of semiconductors in electrolytes. Sacrificial reagents (, methanol or NaSO) are often used to assess the ideal PEC performance of photoanodes in cases of minimised interfacial recombination kinetics as well as accelerated surface reaction kinetics. However, varying the sacrificial reagents in the electrolyte means simultaneously changing the equilibrium potential and the number of electrons required to perform the sacrificial reaction, and thus the thermodynamic and kinetic aspects of the PEC reactions cannot be distinguished.
View Article and Find Full Text PDFRespir Investig
July 2024
Department of Respiratory Medicine, The University of Tokyo. 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
RSC Adv
April 2024
Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan.
The synthesis of zeolites from two-dimensional layered precursors through interlayer crosslinking of the layers is a promising avenue for realizing meticulously designed synthesis routes. However, the presence of defective silanol species in the precursors hinders the achievement of desirable synthesis outcomes. This study focuses on PREFER-a layered precursor for FER-type zeolites-which was synthesized and subjected to a liquid-mediated defect-healing treatment that we recently developed.
View Article and Find Full Text PDFRSC Chem Biol
April 2024
Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
l-Cysteine is a highly reactive amino acid that is modified into a variety of chemical structures, including cysteine sulfinic acid in human metabolic pathways, and sulfur-containing scaffolds of amino acids, alkaloids, and peptides in natural product biosynthesis. Among the modification enzymes responsible for these cysteine-derived compounds, metalloenzymes constitute an important family of enzymes that catalyze a wide variety of reactions. Therefore, understanding their reaction mechanisms is important for the biosynthetic production of cysteine-derived natural products.
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March 2024
Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
In the case of covalent polymers, immiscible polymers can be integrated by covalently linking them together, but such a strategy is not possible in supramolecular polymers. Here we report the supramolecular copolymerization of two porphyrin-based monomers, P and P with side chains bearing cyanobiphenyl (CB) groups at the ends of hydrophobic alkyl or hydrophilic tetraethylene glycol chains, respectively. These monomers undergo self-sorting supramolecular polymerization in highly diluted solutions ([monomer] = 3.
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February 2024
Department of Chemistry, School of Science, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan
As terahertz (THz) and sub-THz region electromagnetic waves are becoming vital for industrial applications such as 5G wireless communication, so too are THz and sub-THz wave absorbing materials. Herein, we report the optical properties of monoclinic zirconia (m-ZrO) nanoparticles in these frequency regions, with different crystalline sizes. The crystalline sizes of the three samples, measured by transmission electron microscopy, are 93 ± 23 nm (denoted 1), 28 ± 14 nm (denoted 2) and 2.
View Article and Find Full Text PDFInorg Chem Front
February 2024
Faculty of Chemistry, Jagiellonian University Gronostajowa 2 30-387 Kraków Poland
Multifunctional optical materials can be realized by combining stimuli-responsive photoluminescence (PL), , optical thermometry, with non-linear optical (NLO) effects, such as second-harmonic generation (SHG). We report a novel approach towards SHG-active luminescent thermometers achieved by constructing unique iridium(iii) complexes, -[Ir(CN)(,-pinppy)] (,-pinppy = (,)-2-phenyl-4,5-pinenopyridine), bearing both a chiral 2-phenylpyridine derivative and cyanido ligands, the latter enabling the formation of a series of molecular materials: (TBA)[Ir(CN)(,-pinppy)]·2MeCN (1) (TBA = tetrabutylammonium) and (Bu-DABCO)[Ir(CN)(,-pinppy)](i)·MeCN (2) (Bu-DABCO = 1-(-butyl)-1,4-diazabicyclo-[2.2.
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February 2024
Department of Chemistry, Graduate School of Science, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
A Cu-responsive allosteric DNAzyme has been developed by introducing bifacial 5-carboxyuracil (caU) nucleobases, which form both hydrogen-bonded caU-A and metal-mediated caU-Cu-caU base pairs. The base sequence was logically designed based on a known RNA-cleaving DNAzyme so that the caU-modified DNAzyme (caU-DNAzyme) can form a catalytically inactive structure containing three caU-A base pairs and an active form with three caU-Cu-caU pairs. The caU-DNAzyme was synthesized by joining short caU-containing fragments with a standard DNA ligase.
View Article and Find Full Text PDFNat Commun
December 2023
Aisin Corporation, 2-1 Asahi-machi, Kariya, Aichi, 448-8650, Japan.
Solid refrigerants exhibiting a caloric effect upon applying external stimuli are receiving attention as one of the next-generation refrigeration technologies. Herein, we report a new inorganic refrigerant, rubidium cyano-bridged manganese-iron-cobalt ternary metal assembly (cyano-RbMnFeCo). Cyano-RbMnFeCo shows a reversible barocaloric effect with large reversible adiabatic temperature changes of 74 K (from 57 °C to -17 °C) at 340 MPa, and 85 K (from 88 °C to 3 °C) at 560 MPa.
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