45 results match your criteria: "Kyoto University Gokasho[Affiliation]"

Although fullerene bisadducts are promising electron-transporting materials for tin halide perovskite solar cells, they are generally synthesized as a mixture of isomeric products that require a complicated separation process. Here, we introduce a phenylene-bridged bis(pyrrolidino)fullerene, Bis-PC, which forms only a single isomer due to geometrical restriction. When used in a tin perovskite solar cell with a PEAFASnI (PEA: phenylethylammonium and FA: formamidinium) light absorption layer, the resulting open-circuit voltage ( ) was 0.

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Dithienoarsinines: stable and planar π-extended arsabenzenes.

Chem Sci

November 2024

Faculty of Molecular Chemistry and Engineering, Graduate School of Science and Technology, Kyoto Institute of Technology Goshokaido-cho, Matsugasaki, Sakyo-ku Kyoto 606-0962 Japan

Stable planar dithienoarsinines were synthesized and structurally characterized. These compounds exhibit monomeric structures in the solution and solid states, avoiding dimerization, even in the absence of steric protection. They exhibited high global aromaticity with 14 or 22π-electron systems.

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Decomposition of brown algae in the ocean by microbiota: biological insights for recycling blue carbon.

Biosci Biotechnol Biochem

November 2024

Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University Gokasho, Uji, Kyoto, Japan.

Brown algae are one of the most abundant biomasses on Earth. To recycle them as blue carbon sources, an effective decomposition system is necessary. This study focused on microorganisms present in seawater that decompose brown algae which contain laminarin and alginate.

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Experimental and Theoretical Characterization of 4π-Electron Möbius Aromatic System of a 1,2-Digermacyclobutadiene.

Angew Chem Int Ed Engl

January 2025

Division of Chemistry, Institute 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.

Article Synopsis
  • The study visualizes the electron-density distribution in the 1,2-digermacyclobutadiene ring, highlighting its unique electron behavior.
  • The GeC ring exhibits a strong Möbius 4π-electron aromatic character, which is distinct from the antiaromatic nature of the all-carbon cyclobutadiene.
  • This research suggests that the presence of germanium alters the electronic properties significantly compared to the carbon-only structure.
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Nanocrystal (NC) superlattices (SLs) have been widely studied as a new class of functional mesoscopic materials with collective physical properties. The arrangement of NCs in SLs governs the collective properties of SLs, and thus investigations of phenomena that can change the assembly of NC constituents are important. In this study, we investigated the dynamic evolution of NC arrangements in three-dimensional (3D) SLs, specifically the morphological transformation of NC constituents during the direct liquid-phase synthesis of 3D NC SLs.

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This study uses a time-dependent first-principles simulation code to investigate the transient dynamics of an ejected electron produced in the monochromatic deposition energy from 11 to 19 eV in water. The energy deposition forms a three-body single spur comprising a hydroxyl radical (OH˙), hydronium ion (HO), and hydrated electron (e). The earliest formation involves electron thermalization and delocalization dominated by the molecular excitation of water.

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The biomimetic design of a transition metal complex based on the iron(iv)-oxo porphyrin π-cation radical species in cytochrome P450 enzymes has been studied extensively. Herein, we translate the functions of this iron(iv)-oxo porphyrin π-cation radical species to an α-ketoacyl phosphonium species comprised of non-metal atoms and utilize it as a light-activated oxygenation auxiliary for -selective oxygenation of anilines. Visible light irradiation converts the α-ketoacyl phosphonium species to the excited state, which acts as a transiently generated oxidant.

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Woody biomass comprising cellulose, hemicellulose, and lignin has been the focus of considerable attention as an alternative energy source to fossil fuel for various applications. However, lignin has a complex structure, which is difficult to degrade. Typically, lignin degradation is studied using β-O-4 lignin model compounds as lignin contains a large number of β-O-4 bonds.

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Practical Antibody Recruiting by Metabolic Labeling with Caged Glycans.

Angew Chem Int Ed Engl

June 2023

Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan.

We propose a de novo glycan display approach that combines metabolic labeling and a glycan-caging strategy as a facile editing method for cell-surface glycans. This method enables the introduction of antigen glycans onto cancer cells to induce immune responses through antibody recruiting. The caging strategy prevents the capture of α-rhamnose (an antigen glycan) by endogenous antibodies during the introduction of the glycan to the targeted cell surface, and subsequent uncaging successfully induces immune responses.

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Many scientific insights into water radiolysis have been applied for developing life science, including radiation-induced phenomena, such as DNA damage and mutation induction or carcinogenesis. However, the generation mechanism of free radicals due to radiolysis remains to be fully understood. Consequently, we have encountered a crucial problem in that the initial yields connecting radiation physics to chemistry must be parameterized.

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Structural Determination and Chemical Synthesis of the N-Glycan from the Hyperthermophilic Archaeon Thermococcus kodakarensis.

Angew Chem Int Ed Engl

March 2023

Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan.

Asparagine-linked protein glycosylations (N-glycosylations) are one of the most abundant post-translational modifications and are essential for various biological phenomena. Herein, we describe the isolation, structural determination, and chemical synthesis of the N-glycan from the hyperthermophilic archaeon Thermococcus kodakarensis. The N-glycan from the organism possesses a unique structure including myo-inositol, which has not been found in previously characterized N-glycans.

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Metal halide perovskites are set to revolutionise photovoltaic energy harvesting owing to an unmatched combination of high efficiency and low fabrication costs. However, to improve the sustainability of this technology, replacing lead with less toxic tin is highly desired. Tin halide perovskites are approaching 15% in power conversion efficiency (PCE), mainly employing PEDOT:PSS as a hole-selective layer.

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Nitrogenase employs a sophisticated electron transfer system and a Mo-Fe-S-C cofactor, designated the M-cluster [(cit)MoFe S C]), to reduce atmospheric N to bioaccessible NH . Previously, we have shown that the cofactor-free form of nitrogenase can be repurposed as a protein scaffold for the incorporation of a synthetic Fe-S cluster [Fe S (SEt) ] . Here, we demonstrate the utility of an asymmetric Mo-Fe-S cluster [Cp*MoFe S (SH)] as an alternative artificial cofactor upon incorporation into the cofactor-free nitrogenase scaffold.

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N -Methyladenosine (m A) is the most common internal RNA modification in the consensus sequence of 5'-RRACH-3'. The methyl mark is added by writer proteins (METTL3/METTL14 metyltransferase complex) and removed by eraser proteins (m A demethylases; FTO and ALKBH5). Recognition of this methyl mark by m A reader proteins leads to changes in RNA metabolism.

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Article Synopsis
  • * The study highlights how thermodynamic issues and the size of side groups affect the PUs' morphology and overall properties.
  • * Increased 1,2-vinyl content results in better phase mixing and smaller microdomains, which leads to more complex pathways for gas molecules, ultimately reducing gas permeability in the membranes.
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L17ER4: A cell-permeable attenuated cationic amphiphilic lytic peptide.

Bioorg Med Chem

May 2022

Laboratory Animal Resource Center, Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8575, Japan. Electronic address:

We have developed a series of attenuated cationic amphiphilic lytic (ACAL) peptides that can efficiently bring immunoglobulin G (IgG) and other functional proteins into cells. Delivery is generally achieved through the coadministration of ACAL peptides with cargo proteins. However, conjugation of ACAL peptides with cargos may be a promising approach for in vivo application to link in vivo outcomes of ACAL peptides and cargos.

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Solar-driven water-splitting has been considered as a promising technology for large-scale generation of sustainable energy for succeeding generations. Recent intensive efforts have led to the discovery of advanced multi-element-compound water-splitting electrocatalysts with very small overpotentials in anticipation of their application to solar cell-assisted water electrolysis. Although photocatalytic and photoelectrochemical water-splitting systems are more attractive approaches for scaling up without much technical complexity and high investment costs, improving their efficiencies remains a huge challenge.

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Silylation of alcohols has generally been known to take place at the sterically most accessible less-hindered hydroxy group. Herein, the catalyst-controlled substrate-selective silylation of primary alcohols, in which the selectivity was controlled independently of the innate reactivity of the hydroxy group, based on the steric environment, is reported. The chain-length-selective silylation of 1,n-amino alcohol derivatives was achieved and 1,5-amino alcohol derivatives showed outstandingly high reactivity in the presence of analogues with a shorter or longer chain length under catalyst-controlled conditions.

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Mixed lead-tin (Pb-Sn) halide perovskites with optimum band gaps near 1.3 eV are promising candidates for next-generation solar cells. However, the performance of solar cells fabricated with Pb-Sn perovskites is restricted by the facile oxidation of Sn(ii) to Sn(iv), which induces self-doping.

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Efficient, robust and environmentally friendly cocatalysts for photocatalysts are important for large-scale solar hydrogen production. Herein, we demonstrate that a Rh-Zr mixed oxide is an efficient cocatalyst for hydrogen evolution. Impregnation of Zr and Rh precursors (Zr/Rh = 5 wt/wt%) formed RhZrO cocatalyst particles on Al-doped SrTiO, which exhibited 31× higher photocatalytic water-splitting activity than a RhO cocatalyst.

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Article Synopsis
  • * Researchers isolated a strain called Sphingobium OW59, which shows strong activity in breaking down complex plant materials like hemicelluloses and can grow on various natural aromatic compounds and sugars.
  • * The study identified a specific gene in OW59 that encodes an enzyme (tannase-family α/β hydrolase) involved in this biodegradation process, contributing to a better understanding of how plant biomass is decomposed in water.
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Isoflavones and soyasaponins are major specialized metabolites accumulated in soybean roots and secreted into the rhizosphere. Unlike the biosynthetic pathway, the transporters involved in metabolite secretion remain unknown. The developmental regulation of isoflavone and soyasaponin secretions has been recently reported, but the diurnal regulation of their biosynthesis and secretion still needs to be further studied.

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We elucidate the formation mechanism of adequate vertical concentration gradients in sequentially deposited poly(3-hexylthiophene-2,5-diyl) (P3HT) and phenyl-C-butyric acid methyl ester (PCBM) bilayer solar cells. Using advanced analytical techniques, we clarify the origins of the enhanced photovoltaic performances of as-deposited and annealed bilayer P3HT/PCBM organic solar cells upon P3HT layer rubbing prior to PCBM deposition. Energy-dispersive X-ray spectroscopy reveals the individual effects of rubbing and annealing on the formation of adequate concentration gradients in the photoactive layers.

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Internal and terminal alkynes react with phosphanylalumanes, i. e., P-Al single-bond species, through heating but without any additional additives.

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Hard X-ray excited optical luminescence is a unique property of materials, which makes them promising for biological imaging applications. However, the preparation of biocompatible contrast agents for hard X-ray excited optical luminescence remains a considerable challenge that has, to date, not been overcome. In this study, we investigated the luminescence properties of protein-directed Au clusters upon hard X-ray irradiation, both in solution and when embedded in films.

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