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81.
82.
Saori Ichinose Mayumi Nakamura Mayu Maeda Rie Ikeda Mitsuhiro Wada Mio Nakazato Yoshihito Ohba Noboru Takamura Takahiro Maeda Kiyoshi Aoyagi Kenichiro Nakashima 《Biomedical chromatography : BMC》2009,23(9):935-939
A semi‐micro column HPLC‐fluorescence method for routine determination of thiol derivatives such as homocysteine (Hcy), cysteine (Cys) and cysteamine (CA) is described. The thiol derivatives labeled with ammonium‐7‐fluorobenzo‐2‐oxa‐1,3‐diazole‐4‐sulfonate (SBD‐F) were isocratically separated within 12 min on a semi‐micro ODS column (Daisopak‐SP‐120‐5‐ODS‐BP) with a mixture of 25 mm acetate buffer (pH 2.00) and CH3CN as a mobile phase. The purity and similarity of SBD‐thiols by a multi‐wavelength fluorescence detector were more than 92.3 and 96.7%. The detection limits of Hcy, Cys and CA at a signal‐to‐noise ratio of 3 were 0.16, 0.47 and 0.03 µm , respectively. Furthermore validation parameters such as accuracy, precision and robustness of the proposed method showed satisfactory results. Almost 850 plasma sample injections (range 572–1076, n = 3) for a column could be performed without differences in retention time and peak heights of labels. As an application of the proposed method, the determination of thiol derivatives in normal human plasma (n = 103) was demonstrated. The correlation coefficients between Hcy vs Cys and Hcy vs CA were 0.38 and −0.35, respectively. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
83.
Magnetic and crystallographic properties have been studied by neutron powder diffraction and measurements of magnetization and magnetization hysteresis-loops for substituted spinels of Zn1?xCuxCr2Se4 with 0.0≤x≤0.3. It is found that the Zn0.85Cu0.15Cr2Se4 spinel has two magnetic phase transitions at 23.0 K (Néel temperature; T N) and 410 K (Curie temperature; T C) and that the Zn0.70Cu0.30Cr2Se4 spinel has magnetic transitions at 24.5 K (T N) and 415 K (T C) on heating. The low-temperature magnetic phase transition is from a spiral antiferromagnet to a ferromagnet, and the high-temperature magnetic phase transition is from a ferromagnet to a paramagnet, while ZnCr2Se4 shows a magnetic phase transition only from a spiral antiferromagnet to a paramagnet at about 21.0 K. From neutron powder diffraction, it is also found that the spinels of Zn1?x Cu x Cr2Se4; 0.0 ≤ x ≤ 0.3. show satellite-like magnetic reflection having indexes (h ± Q, k, l) with Q = 0.470 below T N and short-range order of spins (spin glass-like) above T N. The incommensurate antiferromagnetic phase below T N results from a spiral long-range order of the spins of Cr3+. The intermediate ferromagnetic phase between T N and T C is related not to the spiral spin order but to double-exchange magnetic interaction among Cr3+ and Cr4+ mediated by current carriers, positive holes, which is made by the substitution of Zn2+ ions with Cu1+ ions in Zn1?x Cu x Cr2Se4. 相似文献
84.
Y. Sugawara S. Orisaka E. Hidaka S. Morita 《Applied Physics A: Materials Science & Processing》2001,72(7):S11-S14
Force interaction between an orbital of a dangling bond out of a Si tip apex and an occupied lone-pair orbital on a Si(111)2ǵ-Sb surface is experimentally investigated to clarify the imaging mechanism of noncontact AFM. Sb adatoms with occupied lone-pair orbitals are clearly observed on the 2ǵ zigzag chain structure surface. The discontinuity in the frequency-shift curve is not observed at the Sb sites. Possible contrast mechanisms are discussed and the most understandable in terms of the chemical bonding interaction weaken by the existence of the anti-bonding orbital with one electron. 相似文献
85.
86.
Yoshinobu Morino Ikumasa Hidaka Yoji Oderaotoshi Mitsuo Komatsu Satoshi Minakata 《Tetrahedron》2006,62(52):12247-12251
A new protocol for the cyclization of N-alkenylamides using chloramine-T and iodine is described. When N-alkenylsulfonamides are treated with chloramine-T and iodine, three- to six-membered N-heterocycles are obtained with complete stereoselectivity. The method is compatible with the cyclization of the allylbenzamide or allylbenzthioamide to afford an oxazoline or thiazoline derivative, respectively. Mechanistic studies indicate that the chloramine-T/I2 system functions as an effective iodonium species. 相似文献
87.
Tatsuya Yanagisawa Hiroyuki Hidaka Hiroshi Amitsuka Shintaro Nakamura Satoshi Awaji Elizabeth L. Green 《哲学杂志》2020,100(10):1268-1281
ABSTRACTIn this study, ultrasonic measurements were performed on a single crystal of cubic PrNi2Cd20, down to a temperature of 0.02?K, to investigate the crystalline electric field ground state and search for possible phase transitions at low temperatures. The elastic constant (C11?C12)/2, which is related to the Γ3-symmetry quadrupolar response, exhibits the Curie-type softening at temperatures below ~30?K, which indicates that the present system has a Γ3 non-Kramers doublet ground state. A leveling-off of the elastic response appears below ~0.1?K toward the lowest temperatures, which implies the presence of level splitting owing to a long-range order in a finite-volume fraction associated with Γ3-symmetry multipoles. A magnetic field–temperature phase diagram of the present compound is constructed up to 28?T for H || [110]. A clear acoustic de Haas–van Alphen signal and a possible magnetic-field-induced phase transition at H ~26?T are also detected by high-magnetic-field measurements. 相似文献
88.
Periodic Oscillatory Motion of a Self-Propelled Motor Driven by Decomposition of H2O2 by Catalase 下载免费PDF全文
Prof. Satoshi Nakata Mio Nomura Hiroya Yamamoto Prof. Shunsuke Izumi Prof. Nobuhiko J. Suematsu Prof. Yumihiko Ikura Prof. Takashi Amemiya 《Angewandte Chemie (International ed. in English)》2017,56(3):861-864
A self-propelled motor driven by the enzymatic reaction of catalase adsorbed onto a filter paper floating on an aqueous solution of H2O2 was used to study nonlinear behavior in the motor's motion. An increase in the concentration of H2O2 resulted in a change from no motion to irregular oscillatory motion, periodic oscillatory motion, and continuous motion. The mechanisms underlying oscillation and mode bifurcation are discussed based on experimental results on O2 bubble formation and growth on the underside of the motor. 相似文献
89.
90.
Shuhei Furukawa Kenji Hirai Keiji Nakagawa Yohei Takashima Ryotaro Matsuda Takaaki Tsuruoka Mio Kondo Rie Haruki Daisuke Tanaka Hirotoshi Sakamoto Satoru Shimomura Osami Sakata Susumu Kitagawa 《Angewandte Chemie (International ed. in English)》2009,48(10):1697-1697
A porous copper coordination framework grew epitaxially as a single crystal on the surface of a single crystal of a porous zinc coordination framework, as described by S. Kitagawa and co‐workers in their Communication on page 1766 ff. The picture shows the structural relationship between the copper and zinc frameworks, which has been unveiled by synchrotron surface X‐ray diffraction measurements; in‐plane rotational epitaxial growth compensates for the different lattice constants of the two crystals.