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51.
A rapid, accurate and reproducible high-performance liquid chromatographic method for the simultaneous determination of a new antiplatelet agent, ethyl 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetate (KB-3022), and its main metabolite, 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetic acid (desethyl KB-3022), in biological fluids has been developed. KB-3022 and desethyl KB-3022 in plasma or urine were extracted with a mixture of n-hexane and dichloromethane (1:1), separated on a reversed-phase C18 column with a mixture of 0.01 M (NH4)2HPO4 (pH 3.0), acetonitrile and isopropyl alcohol as a mobile phase, and quantitated by ultraviolet absorbance measurement at 340 nm. 4-[2-(4,5-bis(4-methoxyphenyl)thiazol-2-yl)pyrrol-1-yl]butyric acid was used as an internal standard. The detection limit of KB-3022 in plasma was 3 ng/ml, and that of KB-3022 in urine and desethyl KB-3022 in plasma or urine was 1 ng/ml. The coefficients of variation for the determination of KB-3022 or desethyl KB-3022 in plasma or urine were below 5.6%. This method was applied to the determination of the plasma concentration of KB-3022 and desethyl KB-3022 after intravenous administration to rats. 相似文献
52.
53.
Ikuta Y Ooidemizu M Yamahata Y Yamada M Osa S Matsumoto N Iijima S Sunatsuki Y Kojima M Dahan F Tuchagues JP 《Inorganic chemistry》2003,42(22):7001-7017
A new family of spin crossover complexes, [Fe(II)H(3)L(Me)](NO(3))(2).1.5H(2)O (1), [Fe(III)L(Me)].3.5H(2)O (2), [Fe(II)H(3)L(Me)][Fe(II)L(Me)]NO(3) (3), and [Fe(II)H(3)L(Me)][Fe(III)L(Me)](NO(3))(2) (4), has been synthesized and characterized, where H(3)L(Me) denotes a hexadentate N(6) tripod ligand containing three imidazole groups, tris[2-(((2-methylimidazol-4-yl)methylidene)amino)ethyl]amine. It was found that the spin and oxidation states of the iron complexes with this tripod ligand are tuned by the degree of deprotonation of the imidazole groups and by the 2-methyl imidazole substituent. Magnetic susceptibility and M?ssbauer studies revealed that 1 is an HS-Fe(II) complex, 2 exhibits a spin equilibrium between HS and LS-Fe(III), 3 exhibits a two-step spin transition, where the component [Fe(II)L(Me)](-) with the deprotonated ligand participates in the spin transition process in the higher temperature range and the component [Fe(II)H(3)L(Me)](2+) with the neutral ligand participates in the spin transition process in the lower temperature range, and 4 exhibits spin transition of both the Fe(II) and Fe(III) sites. The crystal structure of 3 consists of homochiral extended 2D puckered sheets, in which the capped tripodlike components [Fe(II)H(3)L(Me)](2+) and [Fe(II)L(Me)](-) are alternately arrayed in an up-and-down mode and are linked by the imidazole-imidazolate hydrogen bonds. Furthermore, the adjacent 2D homochiral sheets are stacked in the crystal lattice yielding a conglomerate as confirmed by the enantiomeric circular dichorism spectra. Compounds 3 and 4 showed the LIESST (light induced excited spin state trapping) and reverse-LIESST effects upon irradiation with green and red light, respectively. 相似文献
54.
Wetting force at three-phase line was measured by the Wilhelmy technique using fibrous solids/liquid/liquid systems. Advancing and receding contact angles were calculated from the wetting forces during fiber immersion and emersion. The obtained results showed that contact angle hysteresis was due to the heterogeneity of the fiber surfaces. The dispersive and polar components of surface free energies of the fibers were determined from the advancing and receding contact angles, respectively. The Hamaker constants of the fibers were estimated from the dispersive components of their surface free energies. 相似文献
55.
Yoshihiro Kawakami Hiromasa Ikuta Masataka Wakihara 《Journal of Solid State Electrochemistry》1998,2(4):206-210
Perovskite-type compounds, Li
x
La(1−
x
)/3NbO3 and (Li0.25La0.25)1−
x
Sr0.5
x
NbO3 as lithium ionic conductors, were synthesized by a solid-state reaction. From powder X-ray diffraction, the solid solution
ranges of the two compounds were determined to be 0≤x≤0.25 and 0≤x≤0.125, respectively. In the Li
x
La(1−
x
)/3NbO3 system, the ionic conductivity of lithium at room temperature, σ25, exhibited a maximum value of 4.7 × 10−5 S · cm−1 at x = 0.10. However, because of the decrease in the lattice parameters with increasing Li concentration x˙, σ25 of the samples decreased with increasing x from 0.10 to 0.25. Also, in the (Li0.25La0.25)1−
x
Sr0.5
x
NbO3 system, the lattice parameter increased with the increase of Sr concentration and the σ25 achieved a maximum (7.3 × 10−5 S · cm−1 at 25 °C) at x = 0.125.
Received: 12 September 1997 / Accepted: 15 November 1997 相似文献
56.
A cyclic cylindrical 3d-4f tetranuclear structure, in which the 3d and 4f magnetic ions are arrayed alternately, has been found to be a suitable molecular design to produce a large magnetic moment and large magnetic anisotropy. Complexes 3-10 with the chemical formula [MLLn(hfac)2]2 ((MII, LnIII) = (Cu, Eu) (3), (Cu, Gd) (4), (Cu, Tb) (5), (Cu, Dy) (6), (Ni, Eu) (7), (Ni, Gd) (8), (Ni, Tb) (9), (Ni, Dy) (10)) have been synthesized, where H3L = 1-(2-hydroxybenzamido)-2-(2-hydroxy-3-methoxybenzylideneamino)ethane and Hhfac = hexafluoroacetylacetone. The powder X-ray diffractions and FAB-mass spectra demonstrated that these complexes assume a similar tetranuclear structure. The crystal structures of 4 and 5 showed that each complex has a cyclic cylindrical tetranuclear CuII2LnIII2 structure, in which the CuII complex functions as a "bridging ligand-complex" to two adjacent LnIII ions. The temperature-dependent magnetic susceptibilities from 2 to 300 K and the field-dependent magnetizations at 2 K from 0 to 5 T have been measured for four pairs of CuII2LnIII2 and NiII2LnIII2, in which compound NiII2LnIII2 containing diamagnetic NiII ion was used as the reference complex to evaluate the CuII-LnIII magnetic interaction. Comparison of the magnetic properties of the CuII2LnIII2 complex with those of the corresponding NiII2LnIII2 complex showed that the magnetic interaction between CuII and EuIII ions is weakly ferromagnetic and that between CuII and either of GdIII, TbIII, and DyIII ions is ferromagnetic. Complex CuII2GdIII2, 4, has an S = 8 spin ground state, due to the ferromagnetic spin coupling between SGd = 7/2 and SCu = 1/2 with coupling constants of J1 = +3.1 cm-1 and J2 = +1.2 cm-1. The magnetic measurements showed that compounds 5 and 6, CuII2LnIII2 (LnIII = Tb, Dy), exhibit large magnetic moments and large magnetic anisotropy due to the LnIII ion. 相似文献
57.
Kobayashi K Kobayashi N Ikuta M Therrien B Sakamoto S Yamaguchi K 《The Journal of organic chemistry》2005,70(2):749-752
The syntheses of various types of hexakis(4-functionalized-phenyl)benzenes 1 and hexakis[4-(4'-functionalized-phenylethynyl)phenyl]benzenes 2 by the cobalt-catalyzed cyclotrimerization of diarylacetylenes and by the Sonogashira coupling reaction of 1e with arylacetylenes, respectively, are described. X-ray crystallographic analysis showed that host 1e or 2f forms a 2-D network by unique I...I or CH...O=C interactions, respectively. 相似文献
58.
Measuring the thermal conductivity of a single carbon nanotube 总被引:1,自引:0,他引:1
Fujii M Zhang X Xie H Ago H Takahashi K Ikuta T Abe H Shimizu T 《Physical review letters》2005,95(6):065502
Although the thermal properties of millimeter-sized carbon nanotube mats and packed carbon nanofibers have been readily measured, measurements for a single nanotube are extremely difficult. Here, we report a novel method that can reliably measure the thermal conductivity of a single carbon nanotube using a suspended sample-attached T-type nanosensor. Our experimental results show that the thermal conductivity of a carbon nanotube at room temperature increases as its diameter decreases, and exceeds 2000 W/mK for a diameter of 9.8 nm. The temperature dependence of the thermal conductivity for a carbon nanotube with a diameter of 16.1 nm appears to have an asymptote near 320 K. The present method is, in principle, applicable to any kind of a single nanofiber, nanowire, and even single-walled carbon nanotube. 相似文献
59.
Negoro Masaaki Shioji Norio Ikuta Yoshiaki Makita Takenori Uchiumi Makoto 《Applied biochemistry and biotechnology》1992,(1):681-692
In order to reduce release of CO2 contained in the flue gas from a power plant, we assumed a system in which the flue gas was directly blown into a pond and
CO2 was fixed on microalgae. We have experimentally examined the basic growth characteristics, such as trace components of culture
medium, effects of impurities from exhaust gas, and light utilization rate of algal productivity, mainly forNonnochloropsis sp. NANNP-2 from SERI collection. Although Ni and V contained in heavy oil burnt ashes dissolve into culture solution, their
concentrations are low, and they have no particular adverse effect on growth as impurities.
Culture medium trace component (i.e., heavy metals and vitamins) are essential for the NANNP-2. However, for the PHAEO-2(Phaeodactylum sp.), the growth rate hardly changes, even if vitamins and heavy metals other than Fe are eliminated. 相似文献
60.
Yagi Kiyohito Maeda Isamu Idehara Kenji Miura Yoshiharu Akano Tohru Fukatu Klyomi Ikuta Yoshiaki Nakamura Hlroshi K. 《Applied biochemistry and biotechnology》1994,45(1):429-436
Applied Biochemistry and Biotechnology - The addition of NH4Cl at concentrations of more than 1 mM completely inhibited nitrogenase-dependent hydrogen evolution using 1 mM succinate as a substrate... 相似文献