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411.
Sakata Y Kuramoto M Ando K Yamaguchi M Kawasaki I Kunitomo J Yokomizo T Ohishi Y 《Organic & biomolecular chemistry》2007,5(19):3083-3086
A series of 3-(4-chlorophenyl)-2-(2-aminothiazol-4-yl)benzo[b]furan derivatives 6-10 were prepared and their leukotriene B(4) inhibitory activity was evaluated. We found that several compounds showed strong inhibition of calcium mobilization in CHO cells overexpressing human BLT(1) and BLT(2) receptors. Among them, 3-(4-chlorophenyl)-2-[5-formyl-2-[(dimethylamino)methyleneamino]thiazol-4-yl]-5-methoxybenzo[b]furan 9b showed the most potent and selective inhibition for the human BLT(2) receptor, and its IC(50) value was smaller than that of the selected positive control compound, ZK-158252. 相似文献
412.
In this work we show that a classical result of A. Hurwitz is still very effective in studying the root analysis of the characteristic equation for a linear functional differential equation. A conjecture was made by Funakubo et al. (2006) [3] regarding the asymptotic stability condition of the zero solution of a linear integro-differential equation of Volterra type. We applied the Hurwitz theorem to the characteristic equation in question and showed the existence of a root with positive real part and solved the conjecture. The Hurwitz theorem is expected to work well for the root analysis in critical cases. 相似文献
413.
Rovillain P Cazayous M Gallais Y Measson MA Sacuto A Sakata H Mochizuki M 《Physical review letters》2011,107(2):027202
We have studied the impact of the magnetic field on the electromagnon excitations in TbMnO? crystal. Applying a magnetic field along the c axis, we show that the electromagnons transform into pure antiferromagnetic modes, losing their polar character. Entering in the paraelectric phase, we are able to track the spectral weight transfer from the electromagnons to the magnon excitations and we discuss the magnetic excitations underlying the electromagnons. We also point out the phonons involved in the phase transition process. This reveals that the Mn-O distance plays a key role in understanding the ferroelectricity and the polar character of the electromagnons. Magnetic field measurements along the b axis allow us to detect a new electromagnon resonance in agreement with a Heisenberg model. 相似文献
414.
M. H. T. Taddei J. F. Macacini R. Vicente J. T. Marumo S. K. Sakata L. A. A. Terremoto 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(3):2267-2272
The radionuclide 55Fe was determined in samples of radioactive wastes from the water cleanup system of the IEA-R1 nuclear research reactor. In order to validate the results, the 55Fe activity concentration was measured in eight waste samples and in six simulated samples containing the most important interfering radionuclides. A simple method was employed to separate and purify 55Fe from other radionuclides present in these samples, combining co-precipitation with ammonium hydroxide and purification with anionic ion-exchange resin, which enables 55Fe to be quantified either by liquid scintillation counting (LSC) or by X-ray spectrometry using a low-energy germanium spectrometer (LEGe). Both measurement methods were used so that the separation and purification process could be confirmed by comparison of spectra with and without the utilization of anionic ion-exchange resin. Activity and interferences were compared in the results obtained from LSC and LEGe measurement methods. 相似文献
415.
Kazutaka Tsuruhami Shigeharu Mori Kanzo Sakata Satoshi Amarume Shigetaka Saruwatari Takeomi Murata 《Journal of carbohydrate chemistry》2013,32(8-9):849-863
The enzyme activity transferring a β‐primeverosyl unit was found from culture filtrates of Penicillium multicolor IAM7153 and was useful for synthesizing a series of β‐primeverosides via a β‐primeverosyl transfer reaction in an aqueous‐organic biphasic system. With the acceptors benzyl alcohol, 2‐phenylethanol, and (Z)‐3‐hexenol, the enzyme induced the transfer products benzyl, 2‐phenylethyl, and (Z)‐3‐hexyl β‐primeverosides in high yields of 51% to 70% based on the donor added. When geraniol and eugenol were used as acceptors, the corresponding geranyl and eugenyl β‐primeverosides were obtained in lower yields of 8% to 12%. The enzyme was an excellent tool for producing naturally occurring β‐primeverosides on a mmol scale. 相似文献
416.
Kanaizuka K Haruki R Sakata O Yoshimoto M Akita Y Kitagawa H 《Journal of the American Chemical Society》2008,130(47):15778-15779
Layer-by-layer bottom-up crystal engineering of metal-organic crystals at the surface of sapphire or glass from organic (rubeanic acid and derivatives) and inorganic (Cu(2+)) components which when mixed in solution form instantly an amorphous solid with high proton conduction. 相似文献
417.
Dr. Yoko Sakata Ryosuke Nakamura Toshihiro Hibi Prof. Dr. Shigehisa Akine 《Angewandte Chemie (International ed. in English)》2023,62(11):e202217048
Switching between the formation/dissociation of rotaxanes is important to control the function of various types of rotaxane-based materials. We have developed a convenient and simple strategy, the so-called “accelerator addition”, to make a static rotaxane dynamic without apparently affecting the chemical structure. As an interlocked molecule that enables tuning of the formation/dissociation speed, a metallorotaxane was quantitatively generated by the complexation of a triptycene-based dumbbell-shaped mononuclear complex, [PdL2]2+ (L=2,3-diaminotriptycene), with 27C9. As a result of the inertness of the Pd2+-based coordination structure, the metallorotaxane was slowly formed (the static state). This rotaxane formation was accelerated 27 times simply by adding Br− as an accelerator (the dynamic state). A similar drastic acceleration was also demonstrated during the dissociation process when Cs+ was added to the metallorotaxane to form the free axle [PdL2]2+ and the 27C9-Cs+ complex. 相似文献
418.
Xuan Shen Hironori Miyashita Li Qi Dun-Ru Zhu Mamoru Hashimoto Kazunori Sakata 《Polyhedron》2008,27(14):3105-3111
In the title complexes, {[(η-C5H5)Fe(η-C5H4)(CO)](C22H21N4)Ni} (1) and {[(η-C5H5)Fe(η-C5H4)(CO)]2(C22H20N4)Ni} (2), one and two electroactive ferrocenes (Fc) were grafted onto the methine of the nickel complex Nitmtaa (H2tmtaa = 4,11-dihydro-5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecine) through the carbonyl groups. The two new complexes were characterized by IR, UV, MS and NMR spectra as well as by DSC measurements. The crystal structure of 1 was determined. Ni coordinates to four nitrogen atoms of tmtaa, and it is almost in the same plane as the N4 plane. The mean Ni–N bond distance in the N4 plane is 1.866 Å. The non-planar, saddle-shaped conformation of H2tmtaa is almost retained in the nickel complex. The symmetry axis of ferrocene is almost parallel to the N4 plane in Nitmtaa. The dihedral angle between the N4 plane in Nitmtaa and the cyclopentadienyl ring in ferrocene is 98.5°. The electrochemistry of 1 and 2 was studied by cyclic voltammetry in CH2Cl2/1 × 10−1 M n-Bu4NClO4 using a glass carbon working electrode. Because of the electron transfer between the electroactive ferrocene and the completely conjugated system of Nitmtaa, the complexes show novel electrochemical properties and the ferrocenes in 1 and 2 act as electron acceptors. 相似文献
419.
420.
Hirai K Furukawa S Kondo M Meilikhov M Sakata Y Sakata O Kitagawa S 《Chemical communications (Cambridge, England)》2012,48(52):6472-6474
Spatiospecific functionalisation of a shell crystal was performed in a core-shell crystal of a porous coordination polymer (PCP) via post-synthetic modification (PSM). The shell crystal allowed the core crystal to selectively accumulate N,N-dimethylaniline (DMA) and afford the intense exciplex fluorescence. 相似文献