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41.
Dr. Tatsuya Takimoto Prof. Hideaki Sasaki Prof. Hirohito Tsue Dr. Hiroki Takahashi Prof. Alexander D. MacKerell Jr. Ayumi Nakamura Katsuya Nakano Eori Okazaki Tatsuki Betsuyaku Ryosuke Tachibana Dr. Kazuhito Hioki Dr. Ozge Yoluk Dr. Sunhwan Jo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(5):1648-1654
A simple approach to the synthesis of heterocyclophane consisting of two 4,4’-bithiazoles has been developed in mild conditions. The heterocyclophane with two short chains was conveniently prepared by Hantzsch thiazoles synthesis using the reaction of 3-tert-butoxycarbonyl-3-azapentanethiocarboxamide with 1,4-dibromobutane-2,3-dione in methanol under reflux for only 15 min. Amino groups at the linkers of this heterocyclophane can be functionalized to give acylated and carbamate derivatives. Their properties as protein kinase inhibitors were investigated, and one of the heterocyclophanes exhibited specific anti-activity for c-mesenchymal epithelial transition factor (IC50=603 nm ), among seven types of protein kinases investigated. The computational site identification by ligand competitive saturation method was used to determine why the one heterocyclophane exhibited strong anti-activity for c-mesenchymal epithelial transition factor. 相似文献
42.
Takashi Okazaki Seiji Ōkubo Yūichi Hoshino Kanji Fujii 《Physics letters. [Part B]》1979,85(1):107-110
The validity of the assumption that decays into mesons proceed via ω, φ and ?0 poles followed by cascade decays is examined. is well reproduced by using and the B → ωπ helicity structure. The structure of OZI-violating transitions including the electromagnetic contribution is examined, and compared with the data on inclusive decay. 相似文献
43.
The effect of MCM-41 on the ESR spectrum of an aqueous spin probe solution was observed. The sharp ESR spectrum turns into a rather broad characteristic one leaving a sharper signal as the minor component, immediately after the addition of MCM-41 powder to the system. This observation indicates that MCM-41 traps the solute molecule into the nanochannel by letting the solvent water form a rather stable molecular cage, since the ESR line shape indicates that the nitroxide radical undergoes anisotropic rotation without being adsorbed on the wall. Thermodynamic parameters for this process are estimated from the temperature dependencies of the trapping efficiency. This process is explained in terms of the surface enthalpy of the liquid specifically intensified in the nanospace. 相似文献
44.
Hiraoka K Asakawa Y Kawashima Y Okazaki S Nakamura M Yamamoto Y Takamizawa A 《Rapid communications in mass spectrometry : RCM》2004,18(20):2437-2442
The effect of the presence of foreign salts (NaCl, aerosol OT, tetra-n-hexylammonium bromide, and CH3COONH4) on the formation of gaseous ions for electrospray (ES) and laser spray (LS) was studied in the positive and negative modes of operations. The ion signals for amino acids show sudden decrease with the concentration of foreign salts greater than 10(-5) M for both ES and LS. When the surface-active counter ions were added, the signal intensities showed a marked decrease for both ES and LS. This may be due to the enrichment of the surface-active counter ions on the surface of the charged droplets. When CH3COONH4 was added to an aqueous solution of 10(-6) M lysozyme chloride, an increase of the signal intensities for (lysozyme+nH)n+ and a decrease in the values of n were observed. The decrease in n may be due to the salt formation of (lysozyme+nH)n+ with the negative acetate ion leading to the reduction of positive charges. 相似文献
45.
46.
D. Nakamura K. Okazaki I. A. Palani M. Higashihata T. Okada 《Applied Physics A: Materials Science & Processing》2011,103(4):959-963
Single-crystalline ZnO nanowires on a sapphire substrate have been synthesized by a nanoparticle-assisted pulsed-laser deposition
(NAPLD) using a pure and Sb2O3 doped ZnO target. Low density and vertically well-aligned ZnO nanowires were grown on hexagonal cone-shape ZnO cores by introduction
of a ZnO buffer layer. More than 90% of the ZnO cores of the Sb-induced ZnO nanowires are formed in the same size of 400 nm.
The ZnO nanowires consist of single-crystalline wurtzite ZnO crystal and grow along [0001] direction. The room-temperature
photoluminescence spectrum exhibited a strong ultraviolet emission at around 380 nm and a relatively low broad band emission
in the visible region, indicating a low concentration of structural defect in the nanowires. Sb can be used as one of the
effective additives to control the morphology and alignment of ZnO nanowires synthesized by NAPLD. 相似文献
47.
Masaharu Okazaki Taizo Ono Kenji Komaguchi Nobuaki Ohta Haruhiko Fukaya Kazumi Toriyama 《Applied magnetic resonance》2009,36(1):89-95
Room temperature fluorine electron nuclear double resonance (ENDOR) has been successfully observed for several superstable
fluorocarbon radicals ·C(C2F4R)(i-C3F7)2 in solution. Three radicals were employed in which CF3, F, and O-c-C6F10SO3C2F5 were introduced as R, and all the hyperfine couplings (hfcs) obtained by ENDOR were assigned with the help of ESR simulation
and ab initio MO calculation. In case of ·C(i-C3F7)3 large 13C and considerable β-fluorine couplings suggest the nonplaner arrangement for the central and three carbons at the β-position, in spite of the
fact that all the methyl fluorine show the same hfc. Therefore, a rapid puckering motion along the C3 axis together with the methyl rotation should average the hfc’s of the 18 fluorine nuclei to give the same value. When one
of the CF3 groups is substituted with an F nucleus, the five CF3 groups give two hfc values, suggesting some dynamics still exists for the molecular frame. When a large group, O-c-C6F10SO3C2F5, is substituted for CF3, all the five CF3 groups become nonequivalent and the ENDOR signal becomes intensive and sharp even at 290 K, indicating that the molecular
frame becomes rigid. The relation between the ENDOR spectra of these systems and the intramolecular dynamics is discussed. 相似文献
48.
49.
A sealed tube dry combustion method that is simple, accurate, and precise for ultramicro determination of halogens in organic compounds has been developed. Samples below 1 mg are heated at 580 °C for 1 h in an electric furnace. After the combustion and absorption of the gaseous halogen, the interior of the tube is rinsed. Subsequent titration is carried out potentiometrically with silver nitrate and yielded standard deviations of 0.21% for chlorine, 0.17% for bromine, and 0.25% for iodine. 相似文献
50.
Yu Ding Ruggero Micheletto Hiroaki Hanada Toshihiko Nagamura Satoshi Okazaki Koji Otsuka 《Optical Review》2002,9(6):277-281
This work describes a groundbreaking process that provides a direct highly localized measurement of the atomic mass on surfaces at room temperature. Employing an original system that joins a scanning tunneling microscopy (STM) device and a time of flight (TOF) mass analyzer, we could previously ionize surface atoms by the combination of an optical laser pulse and an electric pulse at the STM tip. Desorbed ions from a localized area were accelerated and detected by a TOF chamber. We will demonstrate in this paper that high localization and mass discrimination can be obtained even without the aid of an electric pulse from the tip. We reduced the angle of incidence of the laser beam to zero (laser beam parallel to the sample surface). In this condition we were able to demonstrate for the first time ionic desorption at a confinement level of the order of 5-10nm, an order of magnitude better than previous configurations.This paper was originally presented at the 11th Optical Near Field Workshop, which was held on June 28, 2002 at Tokyo Institute of Technology, Yokohama, organized by the Optical Near Field Group of the Optical Society of Japan, an affiliate of the Japan Society of Applied Physics. 相似文献