Tokyo University of Science

About: Tokyo University of Science is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Catalysis & Thin film. The organization has 15800 authors who have published 24147 publications receiving 438081 citations. The organization is also known as: Tōkyō Rika Daigaku & Science University of Tokyo.

Redox Transmetalation of Prickly Nickel Nanowires for Morphology Controlled Hierarchical Synthesis of Nickel/Gold Nanostructures for Enhanced Catalytic Activity and SERS Responsive Functional Material

Abstract: A nonpolar surfactant assisted mild wet chemistry approach has been presented for controlled fabrication of ferromagnetic ultralong (several micrometers in length) prickly nickel nanowires in gram scale with the assistance of hydrazine hydrate as the reducing agent and nickel chloride as the metal ion precursor. Nanowire structures analogous to the natural plant Euphorbia milii resulted due to the magnetic dipole driven self-assembly, and their alignment was oriented desirably with an external magnetic field. Systematic microscopic characterizations identified the nanowire to be pure fcc-Ni (i.e., face-centered cubic Ni) without any signature of contamination, though X-ray photoelectron spectroscopy (XPS) and magnetization measurements refer to the existence of an ultrathin nickel oxide (NiO) layer over the nanostructures. The as-synthesized nanowires were used as a single-source precursor for the evolution of nanometric black NiO when calcined. Again, the Ni nanowires act as a sacrificial template that a...

pH-Sensitive Nanogel Possessing Reactive PEG Tethered Chains on the Surface

Abstract: Poly(ethylene glycol) possessing a polymerizable vinylbenzyl group at one end and a carboxylic acid group at the other end was synthesized via the anionic polymerization of ethylene oxide. 1 H NMR, SEC, and MALDI-TOF-MS studies confirmed that each poly(ethylene glycol) chain quantitatively possessed vinylbenzyl and carboxyl end groups. Emulsion polymerization of 2-(diethylamino)ethyl methacrylate was carried out to obtain a nanometric-sized gel (nanogel) in the presence of a cross-linking agent such as ethylene dimethacrylate, using the obtained R-vinylbenzyl-ˆ-carboxy-PEG as a stabilizing reagent. The size of the obtained nanogels was controllable in the range between 50 and 680 nm. The nanogel was confirmed to have a PEG shell layer with a carboxylic acid group at the distal end of each PEG strands from the œ-potential measurement at varying pHs. The pH-sensitive swelling/deswelling behavior of the nanogels was studied by dyanmic light scattering to confirm their volume phase transition at a pH around 7.0. These prepared nanogels are expected to have potential utility in applications such as diagnostics and controlled drug releasing devices.

Stable and Highly Efficient Electrochemical Production of Formic Acid from Carbon Dioxide Using Diamond Electrodes.

Abstract: High faradaic efficiencies can be achieved in the production of formic acid (HCOOH) by metal electrodes, such as Sn or Pb, in the electrochemical reduction of carbon dioxide (CO2 ). However, the stability and environmental load in using them are problematic. The electrochemical reduction of CO2 to HCOOH was investigated in a flow cell using boron-doped diamond (BDD) electrodes. BDD electrodes have superior electrochemical properties to metal electrodes, and, moreover, are highly durable. The faradaic efficiency for the production of HCOOH was as high as 94.7 %. Furthermore, the selectivity for the production of HCOOH was more than 99 %. The rate of the production was increased to 473 μmol m-2 s-1 at a current density of 15 mA cm-2 with a faradaic efficiency of 61 %. The faradaic efficiency and the production rate are almost the same as or larger than those achieved using Sn and Pb electrodes. Furthermore, the stability of the BDD electrodes was confirmed by 24 h operation.

Condensin II Alleviates DNA Damage and Is Essential for Tolerance of Boron Overload Stress in Arabidopsis

Abstract: Although excess boron (B) is known to negatively affect plant growth, its molecular mechanism of toxicity is unknown. We previously isolated two Arabidopsis thaliana mutants, hypersensitive to excess B (heb1-1 and heb2-1). In this study, we found that HEB1 and HEB2 encode the CAP-G2 and CAP-H2 subunits, respectively, of the condensin II protein complex, which functions in the maintenance of chromosome structure. Growth of Arabidopsis seedlings in medium containing excess B induced expression of condensin II subunit genes. Simultaneous treatment with zeocin, which induces DNA double-strand breaks (DSBs), and aphidicolin, which blocks DNA replication, mimicked the effect of excess B on root growth in the heb mutants. Both excess B and the heb mutations upregulated DSBs and DSB-inducible gene transcription, suggesting that DSBs are a cause of B toxicity and that condensin II reduces the incidence of DSBs. The Arabidopsis T-DNA insertion mutant atr-2, which is sensitive to replication-blocking reagents, was also sensitive to excess B. Taken together, these data suggest that the B toxicity mechanism in plants involves DSBs and possibly replication blocks and that plant condensin II plays a role in DNA damage repair or in protecting the genome from certain genotoxic stressors, particularly excess B.

Oxidative and enantioselective cross-coupling of aldehydes and nitromethane catalyzed by diphenylprolinol silyl ether.

Abstract: The enantioselective, oxidative, one-pot transformation of a C—H bond at the β-atom of an aldehyde into a new C—C bond proceeds under metal-free conditions by the use of an organic oxidizing reagent.