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111.
Alfonso Miranda-Molina Agustín López-Munguía María Luisa San Román Jaime Escalante Marco Antonio Leyva Ana María Puebla Edmundo Castillo Laura Álvarez 《Tetrahedron: Asymmetry》2010,21(1):43-50
The monoglucosyl-inositols α-d-glucopyranosyl-(1→4)-4d-myo-inositol 3 and α-d-glucopyranosyl-(1→1)-1d-myo-inositol 4 were synthesized by a combined enzymatic transglucosylation and hydrolysis strategy, using cyclodextrin glucosyl transferase (CGTase) from Thermoanaerobacter sp., followed by hydrolysis with Aspergillus niger glucoamylase. The glucosides were separated by preparative HPLC and fully characterized by extensive 1D and 2D NMR studies. The structure of the regioisomer 4 was confirmed by X-ray crystallography of its perbenzoylated derivative 4a. Both isomers demonstrated in vivo anti-inflammatory activity at comparative levels to corticosterone on mouse ear oedema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and in rat hind paw oedema induced by carrageenan. 相似文献
112.
113.
Jun‐Qing Wen Zhen‐Yi Jiang Jun‐Qian Li Li‐Ke Cao San‐Yan Chu 《International journal of quantum chemistry》2010,110(7):1368-1375
Density‐functional with generalized gradient approximation (GGA) for the exchange‐correlation potential has been used to calculate the energetically global‐minimum geometries and electronic states of NinAl (n = 2–8) neutral clusters. Our calculations predict the existence of a number of previously unknown isomers. All structures may be derived from a substitution of a Ni atom at marginal positions by an Al atom in the Nin+1 cluster. Aluminum atom remains on the surface of the geometrical configurations. Moreover, these species prefer to adopt three‐dimensional (3D) spacial forms at the smaller number of nickel atoms compared with the pure Nin+1 (n ≥ 3) configuration. Atomization energies per atom for NinAl (n = 2–8) have the same trend as the binding energies per atom for Nin (n = 3–9). The stabilization energies reveal that Ni5Al is the relatively most stable in this series. In comparison with the magnetic moment of pure metal nickel (0.6 μB), the average magnetic moment of Ni atom increases in Ni Al clusters except the Ni3Al. Moreover, except the case of Ni5Al, Ni average magnetic moment decreases when alloyed with Al atoms than that in pure Ni clusters, which originate the effective charge transferring from Al to Ni atoms. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
114.
Jen‐Taut Yeh Chi‐Hui Tsou Wei Lu Ya‐Ming Li Han Wen Xiao Chi‐Yuan Huang Kan‐Nan Chen Chin‐San Wu Wan‐Lan Chai 《Journal of Polymer Science.Polymer Physics》2010,48(9):913-920
Fourier transform infrared and nuclear magnetic resonance results suggest that the carboxylic acid groups of poly(lactic acid) (PLA) molecules react with the hydroxyl groups of FePol (FP) molecules during the melt‐blending of PLAxFPy specimens. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) experiments of PLA and PLA/FP specimens suggest that only small amounts of poor PLA and/or FP crystals are present in their corresponding melt crystallized specimens. In fact, the percentage crystallinity, peak melting temperature, and onset re‐crystallization temperature values of PLA/FP specimens reduce gradually as their FP contents increase. However, the glass transition temperatures of PLA molecules found by DSC and DMA reduce to a minimum value as the FP contents of PLAxFPy specimens reach 6 wt %. Further DMA and morphological analysis of PLA/FP specimens reveal that FP molecules are compatible with PLA molecules at FP contents equal to or less than 6 wt %, as no distinguished phase‐separated FP droplets and tan δ transitions were found on fracture surfaces and tan δ curves of PLA/FP specimens, respectively. In contrast to PLA, the FP specimen exhibits highly deformable and tearing properties. After blending proper amounts of FP in PLA, the inherent brittle deformation and poor tearing behavior of PLA were successfully improved. Possible reasons accounting for these interesting crystallization, compatible and tearing properties of PLA/FP specimens are proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 913–920, 2010 相似文献
115.
With the general third-order equations of motion for a test particle, Synge's third-order orbital equations at great distance in the weak gravitational field generated by a massive body are derived. The body has an axis of symmetry around which is rotating steadily. The results found for the advance of perihelion using first integrals of motion for the general equations show that the effect due to the inner stress of the body can be derived for orbits with inclination with respect to the equator of the body. Then, by means of the variation of the parameters method, we obtain with the equations at great distance the corresponding perturbations on the elements of such orbits in the field considered. These perturbations result to be of second order with regard to the mass of the body (the basis of the approximation). 相似文献
116.
117.
Eduardo Rodríguez de San Miguel Anel V. Garduño-García María E. Núñez-Gaytán Julio C. Aguilar Josefina de Gyves 《Journal of membrane science》2008
An organic–inorganic hybrid membrane was synthesized and evaluated for gold(III) transport from concentrated hydrochloric acid medium. The membrane was prepared by crosslinking of hydroxy terminated poly(dimethylsiloxane) with (3-aminopropyl) triethoxysilane in the presence of the commercial extractant Kelex 100. An optimization of the transport conditions was performed and selectivity with respect to copper(II) and zinc(II) determined. Around 70% of Au(III) was transported from an initially 10 ppm aqueous solution under optimized conditions with high selectivity towards 50 ppm of Cu(II) or 100 ppm of Zn(II) in 6 h. In addition the membrane extraction equilibrium reaction and its corresponding extraction equilibrium constant were evaluated and compared to those obtained in liquid–liquid solvent extraction. Membrane characterization was attained by ATR-FTIR spectroscopy. 相似文献
118.
An immunoaffinity column for the selective extraction and concentration of the herbicide triclopyr from water samples and quantification on line by HPLC has been developed. The immunoaffinity device was prepared by immobilising triclopyr antibodies to hydrazide derivatized azlactona beds. Efficient desorption of bound triclopyr was achieved with 70% ethanol/water solution. The column was evaluated regarding selectivity, recovery, capacity, saturation volume and reusability. Obtained results show that immunoaffinity chromatography (IAC) can be used for quantitative extraction, concentration and determination of triclopyr from water samples. 相似文献
119.
Luiz San Martin 《Semigroup Forum》1992,44(1):376-387
LetG be a connected semi-simple Lie group withfinite centre andS∋G a subsemigroup withnonvoid interior. The purpose of this article is to show thatS innot simultaneously leftand right reversible unlessS=G. 相似文献
120.
Jaime Ortega Jorge San Martín Loredana Smaranda 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2007,58(6):969-993
In this paper, we use the Bloch wave method to study the asymptotic behavior of the solution of the Laplace equation in a
periodically perforated domain, under a non-homogeneous Neumann condition on the boundary of the holes, as the size of the
holes goes to zero more rapidly than the domain period. This method allows to prove that, when the hole size exceeds a given
threshold, the non-homogeneous boundary condition generates an additional term in the homogenized problem, commonly referred
to as “the strange term” in the literature. 相似文献