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991.
Takayuki Kato Koji Tsubono Osamu Kamo Toshiyo Kato Kazuo Furihata Takashi Fujimoto Tomoya Machinami Mitsuru Tashiro 《Magnetic resonance in chemistry : MRC》2009,47(11):948-952
The 1H and 39K longitudinal relaxation times (T1) and 1H diffusion coefficients were measured to investigate the complex formation of 1,6‐anhydro‐β‐maltotriose and potassium ions. Although the 1H‐T1 values of H3′, H5′, H1″ and H4″ decreased in the presence of potassium ions, 1H chemical shifts and 1H diffusion coefficients did not show significant changes. The long‐range coupling constants of 3JC?H around the glycosyl bonds did not show significant changes either. In the measurements of 39K spectra, the 39K signal obviously broadened and the 39K‐T1 values decreased in the presence of 1,6‐anhydro‐β‐maltotriose, indicating the complex formation of 1,6‐anhydro‐β‐maltotriose and potassium ions. These results indicate that the conformation and molecular volume were unaffected in the complex formation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
992.
Tsuyoshi Michinobu Fumiaki Kato Jun Inui Hiroyuki Nishide 《Journal of polymer science. Part A, Polymer chemistry》2009,47(18):4577-4586
This article describes the synthesis of the two‐dimensionally extended aromatic polyamines by polycondensation between the tri‐sec‐amine monomer and p‐phenylenediamine‐based dibromide, the polyradical generation by chemical and electrochemical oxidations, and the hole‐transporting properties. The molecular weights (Mn) of the polyamines, 3a and 3b , were 7700 and 5000, respectively, and both polymers were very soluble in the typical organic solvents, ensuring a good film formation capability by a spin‐coating technique. The thermal stability of the aromatic polyamines, elucidated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), was quite high. More important, the cross‐conjugated structure is essential for the controlled radical generation and the maintenance of the radical stability. Cyclic voltammograms of the neutral polyamines in the presence of 1 vol % of trifluoroacetic acid and the intervalence bands of the partially oxidized polyamines with NOPF6 revealed that the generated radicals delocalize over the p‐phenylenediamine moieties. The half‐life of the polyradicals was about 12 h even under ambient conditions, which allowed us to fabricate and measure the hole‐only devices. The charge‐transporting properties of the polyamines were dramatically changed by the partial oxidation (20 mol %/aminium unit) with NOPF6. The neutral polyamines showed the conventional injection‐limit behaviors, whereas the hole‐transporting behaviors of the polyradicals are bulk‐limit and highly dependent on the chemical structure. The efficient hole‐transport of the all‐conjugated poly(aminium cationic radical)s was for the first time realized for the polyradical of 3b . © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4577–4586, 2009 相似文献
993.
Kunio Hiroi Fumiko Kato Takamasa Oguchi Shinya Saito Takanori Sone 《Tetrahedron letters》2008,49(22):3567-3569
α-Allenylcyclopropanedicarboxylates, for which a novel synthetic method has been devised by conjugate addition of a copper hydride (Stryker) reagent to α-cyclopropylpropargylic esters, have been newly found to be smoothly converted to methylenecyclopentene derivatives under mild reaction conditions by further treatment with the copper hydride reagent. The mechanistic pathway is discussed. 相似文献
994.
995.
Akira Onishi Makoto Endo Shigeki Uchino Naoto Harashima Naoki Oguri 《Journal of separation science》1993,16(6):353-357
A new multichannel autosampler which can automatically analyze up to twenty samples in sequence has been developed for Curie point pyrolysis – capillary GC. Compared with a previous system [1] the transfer line between the pyroysis unit and chromatograph is shorter, and thus has less dead volume, and can be operated at a higher temperature (300 °C). The relative yields of higher boiling point, highly polar, and thermally labile pyrolysates generated from polymers, and the reproducibility, were better than those obtained from the previous autosampler. To facilitate rapid operation an additional flow controller is installed on the new device to shorten the time taken to purge air from the sampler. 相似文献
996.
Shigeki Nakagawa Hiroki Tanaka Masahiko Naoe 《Journal of magnetism and magnetic materials》1993,120(1-3):349-352
One of the origins of perpendicular magnetic energy of Fe-Zr films may be attributed to the structural inhomogeneity of Fe-rich alloy crystallites in a Fe-Zr amorphous matrix. Fe-Ni-Zr films deposited on PEN tape substrates at about 90°C exhibited large Ku with appropriately large 4πMs suitable for flexible recording media. 相似文献
997.
The WAP-8294A complex was isolated from the fermentation broth of Lysobacter sp. WAP-8294, whose major component, WAP-8294A2, showed a strong activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci in vitro, and also exhibited a potent activity against MRSA in vivo. The previous separation procedure using the conventional chromatographic methods was laborious and time-consuming, and the recovery of the desired compound was often unsatisfactory. In the present study, high-speed counter-current chromatography (HSCCC) was applied to the separation of the main components of the WAP-8294A complex. Due to the high polarity of the target compounds, we selected a hydrophilic two-phase solvent system composed of n-butanol-ethyl acetate-aqueous 0.005 M trifluoroacetic acid (1.25:3.75:5, v/v/v) which provided a suitable range of partition coefficient values for these compounds. Although the settling time of this solvent system was much longer than the optimum range, suggesting a low retention of the stationary phase under the standard experimental conditions, the separation was successfully performed at the low flow-rate of 0.5 ml/min. A sample size of 25 mg yielded pure fractions of three components (1-6 mg). The identification of each component was carried out by HPLC and fast atom bombardment mass spectrometry. The method will contribute to the clinical development of WAP-8294A2 as an anti-MRSA agent. 相似文献
998.
999.