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951.
Yongliang Yang Guohui Li Dongyu Zhao Haoyang Yu Xiliang Zheng Xiangda Peng Xiaoe Zhang Ting Fu Xiaoqing Hu Mingshan Niu Xuefei Ji Libo Zou Jin Wang 《Chemical science》2015,6(5):2812-2821
Cognition and memory impairment are hallmarks of the pathological cascade of various neurodegenerative disorders. Herein, we developed a novel computational strategy with two-dimensional virtual screening for not only affinity but also specificity. We integrated the two-dimensional virtual screening with ligand screening for 3D shape, electrostatic similarity and local binding site similarity to find existing drugs that may reduce the signs of cognitive deficits. For the first time, we found that pazopanib, a tyrosine kinase inhibitor marketed for cancer treatment, inhibits acetylcholinesterase (AchE) activities at sub-micromolar concentration. We evaluated and compared the effects of intragastrically-administered pazopanib with donepezil, a marketed AchE inhibitor, in cognitive and behavioral assays including the novel object recognition test, Y maze and Morris water maze test. Surprisingly, we found that pazopanib can restore memory loss and cognitive dysfunction to a similar extent as donepezil in a dosage of 15 mg kg–1, only one fifth of the equivalent clinical dosage for cancer treatment. Furthermore, we demonstrated that pazopanib dramatically enhances the hippocampal Ach levels and increases the expression of the synaptic marker SYP. These findings suggest that pazopanib may become a viable treatment option for memory and cognitive deficits with a good safety profile in humans. 相似文献
952.
We present a structure theorem for dual quasi-Hopf bicomodules, and also obtain the structure theorem C ≌ D ? H for dual quasi-Hopf module coalgebras, where H is a dual quasi-Hopf algebra, C a right H-module coalgebra, and D a left H-comodule coalgebra in the tensor category H M induced from C, and D ? H the smash coproduct introduced by Bulacu and Nauwelaerts. 相似文献
953.
Juan He Ruihe Lv Haijun Zhan Huizhi Wang Jie Cheng Kui Lu Fengcheng Wang 《Analytica chimica acta》2010,674(1):53-58
A novel molecularly imprinted polymer (MIP) that was applied to a solid-phase micro-extraction (SPME) device, which could be coupled directly to gas chromatograph and mass spectrometer (GC/MS), was prepared using dibutyl phthalate (DBP) as the template molecule. The characteristics and application of this fiber were investigated. Electron microscope images indicated that the MIP-coated solid-phase micro-extraction (MI-SPME) fibers were homogeneous and porous. The extraction yield of DBP with the MI-SPME fibers was higher than that of the non-imprinted polymer (NIP)-coated SPME (NI-SPME) fibers. The MI-SPME fibers had a higher selectivity to other phthalates that had similar structures as DBP. A method was developed for the determination of phthalates using MI-SPME fibers coupled with GC/MS. The extraction conditions were optimized. Detection limits for the phthalate samples were within the range of 2.17-20.84 ng L−1. The method was applied to five kinds of phthalates dissolved in spiked aqueous samples and resulted in recoveries of up to 94.54-105.34%, respectively. Thus, the MI-SPME fibers are suitable for the extraction of trace phthalates in complicated samples. 相似文献
954.
Ke-Jing Huang Cong-Hui Han Jun-Yong Sun De-Jun Niu Zhi-Wei Wu Ya-Ping Xue Li-Juan Zhang Xiao-Qin Xiong 《Chromatographia》2010,71(11-12):1049-1054
The purpose of the present work is to develop a simple, rapid, sensitive and accurate method for the derivatization and subsequently preconcentration of Hg(II) and the determination of its derivative, diphenylmercury, in natural water samples using gas chromatography-flame ionization detection. The method is based on the diphenylation using phenyl boronic acid, subsequent extraction of phenylmercury into a single drop of an organic solvent (toluene), followed by gas chromatography-flame ionization detection GC-FID analysis of the extract. The pH of the feed solution was kept in pH 5 with acetate buffer solution. Thus, the optimized conditions are: organic solvent, toluene; derivatization time, 10 min; extraction time, 15 min; microdrop volume, 1.6 μL; stirring rate, 600 rpm; sample volume, 5 mL. The limit of detection (LOD), calculated on the basis of five replicates was 0.02 μg mL?1. The relative standard deviation of the method (RSD%, n = 5) was 3.0. Linear range was between 0.05 and 5 μg mL?1 and preconcentration factor obtained for phenyl-mercury was 105. 相似文献
955.
A facile strong cation-exchange stationary phase based on propylsulfonic acid functionalized silica was prepared through the oxidation in situ of 3-mercaptopropyl silica and characterized by elemental analysis and X-ray photoelectron spectroscopy. The phase was used to separate monovalent and divalent inorganic cations with strong acid as mobile phase. Simultaneous separation of alkali metals and alkaline earth metals was examined and the cations sodium, magnesium and calcium in tap water were determined. 相似文献
956.
Shengxiao Zhang Hongyun Niu Zhengjun Hu Yaqi Cai Yali Shi 《Journal of chromatography. A》2010,1217(29):4757-4764
The carbon coated Fe3O4 nanoparticles (Fe3O4/C) were synthesized by a simple hydrothermal reaction and applied as solid-phase extraction (SPE) sorbents to extract trace polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. The Fe3O4/C sorbents possess high adsorption capacity and extraction efficiency due to strong adsorption ability of carbon materials and large surface area of nanoparticles, and only 50 mg of sorbents are required to extract PAHs from 1000 mL water samples. The adsorption attains equilibrium rapidly and analytes are eluted with acetonitrile readily. Salinity and solution pH have no obvious effect on the recoveries of PAHs, which avoids fussy adjustment to water sample before extraction. Under optimized conditions, the detection limits of PAHs are in the range of 0.2–0.6 ng L−1. The accuracy of the method was evaluated by the recoveries of spiked samples. Good recoveries (76–110%) with low relative standard deviations from 0.8% to 9.7% are achieved. This new SPE method provides several advantages, such as high extraction efficiency, high breakthrough volumes, convenient extraction procedure, and short analysis times. To our knowledge, this is the first time that Fe3O4/C nanoparticles are used for the pretreatment of environmental water samples. 相似文献
957.
Huang YL Wang R Niu TC Kera S Ueno N Pflaum J Wee AT Chen W 《Chemical communications (Cambridge, England)》2010,46(47):9040-9042
Molecular dipole chain arrays of chloroaluminium phthalocyanine (ClAlPc) on the graphite surface have been investigated by scanning tunneling microscopy. The inter-chain spacing can be tuned by the co-adsorption of di-indenoperylene (DIP) via nanoscale phase separation. 相似文献
958.
Jixia Song Junhua Yuan Fei Li Dongxue Han Jiangfeng Song Li Niu 《Journal of Solid State Electrochemistry》2010,14(10):1915-1922
Oxygen electrochemical reduction on gold–polyaniline (Au–PANI) porous nanocomposite-modified glassy carbon electrode in basic
media was described. The as-prepared Au–PANI porous nanocomposite showed superior tunable activity for electrochemical reduction
of oxygen. The specific surface area of Au–PANI porous nanocomposites was evaluated to be about 11.3 m2 g−1 through a convenient voltammetric approach. Rotating ring-disk electrode experiments further demonstrated the number of electrons
exchanged in oxygen reduction increased from 2e to 4e with increasing the trigger potential from 300, to 500, 700 mV. The
tunable activity in electrochemical reduction of oxygen was achieved as a result of positive potential-induced formation and
reduction of Au surface oxide. However, the tunable oxygen reduction reaction is fit for applying potential in a linear positive-going
potential sweep. Irreversible ORR tunability was found after a more active surface formed at 700 mV. To optimize the applied
potential window on these Au-based porous materials has potential applications such as in electrochemical sensing, fuel cells,
or getting rid of the interference from the coexisted substances. 相似文献
959.
Niu Z He J Russell TP Wang Q 《Angewandte Chemie (International ed. in English)》2010,49(52):10052-10066
The generation of novel multifunctional materials with hierarchical ordering is a major focus of current materials science and engineering. For such endeavors, fluid interfaces, such as air-liquid and liquid-liquid interfaces, offer ideal platforms where nanoparticles or colloidal particles can accumulate and self-assemble. Different assembly processes and reactions have been performed at fluid interfaces to generate hierarchical structures, including two-dimensional crystalline films, colloidosomes, raspberry-like core-shell structures, and Janus particles, which lead to broad applications in drug delivery and controlled release, nanoelectronics, sensors, food supplements, and cosmetics. 相似文献
960.