30 results match your criteria: "The University of Tokyo 5-1-5 Kashiwanoha[Affiliation]"

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.

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Nicotine adenine dinucleotide derivatives NADH and NADPH are intimately involved in energy and electron transport within cells. The fluorescent ubiquinone-rhodol (Q-Rh) probe is used for NADPH activation monitoring. Q-Rh reacts with NADPH yielding its quenched hydroquinone-rhodol (HQ-Rh) form with concurrent NADPH activation ( NADP formation).

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With the emergence of the energy crisis and the development of flexible electronics, there is an urgent need to develop new reliable energy supply devices with good flexibility, stable energy storage, and efficient energy transfer. Porous carbon materials have been proven to enhance the efficiency of ion transport, as the nanospaces within them serve as pathways for mass transport. However, they have been mainly investigated in the electrodes of supercapacitors and batteries.

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We demonstrate on-surface deprotection of methylenedioxy groups which yielded graphene nanoribbons (GNRs) with edges functionalized by hydroxy groups. While anthracene trimer precursors functionalized with hydroxy groups did not yield GNRs, it was found that hydroxy groups are first protected as methylenedioxy groups and then deprotected during the cyclo-dehydrogenation process to form GNRs with hydroxy groups. The X-ray photoemission spectroscopy and non-contact atomic force microscopy studies revealed that ∼20% of the methylenedioxy turned into hydroxy groups, while the others were hydrogen-terminated.

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Synthesis of a metal-organic framework by plasma in liquid was demonstrated with HKUST-1 as an example. HKUST-1 synthesized by this method contains a higher amount of monovalent copper ions than that synthesized by other conventional methods. The enhanced water stability was also confirmed.

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Kinetic and deuterium isotope analyses of ammonia electrochemical synthesis.

RSC Adv

May 2021

Department of Transdisciplinary Science and Engineering, School of Environment and Society, Tokyo Institute of Technology 2-12-1 Ookayama, Meguro-ku Tokyo 152-8550 Japan

The mechanism of electrochemical promotion of ammonia formation was investigated by kinetic and deuterium isotope analyses using a cell with a Pt (anode)|BaCeYO (BCY)|Fe (cathode) configuration on the introduction of a gaseous mixture of H(D)-N to the cathode at 550 °C. To clarify the mechanism of electrochemical ammonia synthesis, the reaction orders for hydrogen, , and nitrogen, , were investigated. The values of and did not change after applying a negative voltage, which indicates that the reaction mechanism at rest potential is the same as that with cathodic polarization.

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In this review article, the recent examples of nanoarchitectonics on living cells are briefly explained. Not limited to conventional polymers, functional polymers, biomaterials, nanotubes, nanoparticles (conventional and magnetic ones), various inorganic substances, metal-organic frameworks (MOFs), and other advanced materials have been used as components for nanoarchitectonic decorations for living cells. Despite these artificial processes, the cells can remain active or remain in hibernation without being killed.

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In this work, we report a high-yield one-pot synthesis of polyrotaxane (PR), composed of (2-hydroxypropyl)-α-cyclodextrin (hpCD) and polyethylene glycol (PEG), with well-defined hpCD threading ratios controllable across a wide range from 0.64% to 10%. In hpCD/PEG aqueous solutions, hpCDs are well dispersed and threaded spontaneously into hpCDs to form a pseudo-PR (pPR) structure.

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Article Synopsis
  • - Organic hydroperoxides (ROOHs) are important reactive species in the atmosphere, primarily found in aerosols and cloud droplets due to their low volatility and high hydrophilicity, but their decomposition in liquid phases is not well understood.
  • - The study investigates the temperature-dependent decomposition of α-alkoxyalkyl-hydroperoxides (α-AHs) from α-terpineol in different alcohols, finding that their decay follows a single-exponential pattern and that higher temperatures increase the decomposition rate.
  • - The authors propose that a proton-catalyzed mechanism is key to the decomposition of α-AHs in acidic conditions, suggesting these processes could release hydroxyl radicals (HO) and other multifunctionalized compounds
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Helicene is a functional material with chirality caused by its characteristic helical geometry. The inversion of its helicity by external stimuli is a challenging task in the advanced control of the molecular chirality. This study fabricated a novel helical molecule, specifically a pentahelicene-analogue twisted aromatic hydrocarbon fused with a graphene nanoribbon, on-surface synthesis using multiple precursors.

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Revisiting molecular adsorption: unconventional uptake of polymer chains from solution into sub-nanoporous media.

Chem Sci

October 2021

Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo 5-1-5 Kashiwanoha, Kashiwa Chiba 277-8561 Japan

Adsorption of polymers from the solution phase has been extensively studied to cope with many demands not only for separation technologies, but also for the development of coatings, adhesives, and biocompatible materials. Most studies hitherto focus on adsorption on flat surfaces and mesoporous adsorbents with open frameworks, plausibly because of the preconceived notion that it is unlikely for polymers to enter a pore with a diameter that is smaller than the gyration diameter of the polymer in solution; therefore, sub-nanoporous materials are rarely considered as a polymer adsorption medium. Here we report that polyethylene glycols (PEGs) are adsorbed into sub-nanometer one-dimensional (1D) pores of metal-organic frameworks (MOFs) from various solvents.

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Lockdown measures have been a "panacea" for pandemic control but also a violent "poison" for economies. Lockdown policies strongly restrict human mobility but mobility reduce does harm to economics. Governments meet a thorny problem in balancing the pros and cons of lockdown policies, but lack comprehensive and quantified guides.

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The purpose of the two studies was to investigate the relationships among student athletes' identity and mental health during the COVID-19 pandemic. In addition, this study aimed to clarify the relationship between perceived social support from teammates and mental health in student-athletes. Two studies were conducted to investigate and clarify the mental health states of student-athletes in Japan during the COVID-19 pandemic.

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Carbonization of single polyacrylonitrile chains in coordination nanospaces.

Chem Sci

June 2020

Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo 5-1-5 Kashiwanoha, Kashiwa Chiba 277-8561 Japan

It has been over half a century since polyacrylonitrile (PAN)-based carbon fibers were first developed. However, the mechanism of the carbonization reaction remains largely unknown. Structural evolution of PAN during the preoxidation reaction, a stabilization reaction, is one of the most complicated stages because many chemical reactions, including cyclization, dehydration, and cross-linking reactions, simultaneously take place.

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Molecular machines are often regarded as molecular artworks and sometimes as fancy molecular toys. However, many researchers strive to operate molecular machines as useful tools for realistic practical applications. In this perspective article, shifting the working environment of molecular machines from solution to interfacial media is discussed from the viewpoint of their evolution from scientific toys to useful tools.

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A highly periodic electrostatic potential, even though established in van der Waals bonded organic crystals, is essential for the realization of a coherent band electron system. While impurity doping is an effective chemical operation that can precisely tune the energy of an electronic system, it always faces an unavoidable difficulty in molecular crystals because the introduction of a relatively high density of dopants inevitably destroys the highly ordered molecular framework. In striking contrast, a versatile strategy is presented to create coherent 2D electronic carriers at the surface of organic semiconductor crystals with their precise molecular structures preserved perfectly.

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Solar PV has seen a spectacular market development in recent years and has become a cost competitive source of electricity in many parts of the world. Yet, prospective observations show that the coronavirus pandemic could impact renewable energy projects, especially in the distributed market. Tracking and attributing the economic footprint of COVID-19 lockdowns in the photovoltaic sector poses a significant research challenge.

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Recently, viruses have been regarded as useful molecular assemblies for materials applications rather than as disease-causing agents. The orderly assembled structures of the viruses are highly related to the resultant properties and functions of the assemblies; however, methods to control the assembly are still limited. Here, we demonstrated the assembly of filamentous viruses into hierarchical nano- to microstructures at liquid/liquid interfaces through emulsification in a controlled manner.

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Utilizing the intrinsic mobility-strain relationship in semiconductors is critical for enabling strain engineering applications in high-performance flexible electronics. Here, measurements of Hall effect and Raman spectra of an organic semiconductor as a function of uniaxial mechanical strain are reported. This study reveals a very strong, anisotropic, and reversible modulation of the intrinsic (trap-free) charge carrier mobility of single-crystal rubrene transistors with strain, showing that the effective mobility of organic circuits can be enhanced by up to 100% with only 1% of compressive strain.

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One of the key issues for an upcoming hydrogen energy-based society is to develop highly efficient hydrogen-storage materials. Among the many hydrogen-storage materials reported, transition-metal hydrides can reversibly absorb and desorb hydrogen, and have thus attracted much interest from fundamental science to applications. In particular, the Pd-H system is a simple and classical metal-hydrogen system, providing a platform suitable for a thorough understanding of ways of controlling the hydrogen-storage properties of materials.

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The challenges of pollution, environmental science, and energy consumption have become global issues of broad societal importance. In order to address these challenges, novel functional systems and advanced materials are needed to achieve high efficiency, low emission, and environmentally friendly performance. A promising approach involves nanostructure-level controls of functional material design through a novel concept, nanoarchitectonics.

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Bacterial and protozoan sugar chains contain glycosyl 1-phosphate repeating structures; these repeating structures have been studied for vaccine development. The fluorinated analogues of [β-Gal-(1→4)-α-Man-(1→6)-P-] , which are glycosyl 1-phosphate repeating structures found in , were synthesised using the solid-phase phosphoramidite method. This method has been less extensively studied for the synthesis of glycosyl 1-phosphate units than -phosphonate chemistry.

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Herein, we modulate the chromic response of a highly colored tetrapyrrole macrocycle, namely, tetrakis(3,5-di--butyl-4-oxocyclohexadien-2,5-yl)porphyrinogen () by structural modification. N-Benzylation at the macrocyclic nitrogen atoms leads to stepwise elimination of the two calix[4]pyrrole-type binding sites of and serial variation of the chromic properties of the products, double N-benzylated and tetra N-benzylated . The halochromic (response to acidity) and solvatochromic (response to solvent polarity) properties were studied by using UV/Vis spectroscopy and NMR spectroscopy in nonpolar organic solvents.

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Printed and flexible electronics requires solution-processable organic semiconductors with a carrier mobility (μ) of ≈10 cm V s as well as high chemical and thermal durability. In this study, chryseno[2,1-:8,7-']dithiophene (ChDT) and its derivatives, which have a zigzag-elongated fused π-electronic core (π-core) and a peculiar highest occupied molecular orbital (HOMO) configuration, are reported as materials with conceptually new semiconducting π-cores. ChDT and its derivatives are prepared by a versatile synthetic procedure.

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Key Questions in Marine Megafauna Movement Ecology.

Trends Ecol Evol

June 2016

Australian Institute of Marine Science, c/o The UWA Oceans Institute, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.

It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field.

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