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Di N.,Central South University | Di N.,Chongqing Chemical Industry Vocational College | Xiao J.-J.,Central South University | Liu G.-Y.,Central South University | And 4 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2014

A new sulfide mineral collector, N-butoxypropyl-N'-ethoxycarbonyl thiourea (BOPECTU) was introduced, and its reaction with metal ions such as Cu2+, Zn2+, Fe3+ or Fe2+, its flotation performance to chalcopyrite, pyrite or sphalerite, and its adsorption mechanisms on the three sulfide mineral surfaces were investigated. The results show that BOPECTU reacts chemically with Cu2+ through its S and N atoms to form a new chelate compound, but no reaction of BOPECTU with Zn2+, Fe3+ or Fe2+ is observed under the same test conditions. BOPECTU is an excellent collector for chalcopyrite and the recommended pH values for chalcopyrite flotation are 6.0-10.0, while BOPECTU exhibits weak selectivity for pyrite and sphalerite. The results of IR spectra demonstrate that BOPECTU adsorbs on chalcopyrite surface mainly through chemisorption, and adsorbs on pyrite or sphalerite surfaces through physisorption. Source

Qiao L.,Chongqing University | Liao M.,Chongqing Chemical Industry Vocational College | Chen S.,Chongqing University | Wei Z.,Chongqing University | Zhang S.,Chongqing University
Journal of Solid State Electrochemistry | Year: 2014

Nanoscale Pt3Ni/functionalized multiwalled carbon nanotubes (FMWCNTs) catalysts, successfully synthesized by anchoring nickel-platinum alloy nanoparticles on FMWCNTs, are presented in this paper. Compared with conventional commercial Pt/C catalysts, the preliminary results revealed that the Pt3Ni/FMWCNTs catalysts demonstrated not only higher specific activity for oxygen reduction reaction (ORR) but also outstanding stability. The enhancement in the stability of the Pt3Ni/FMWCNTs catalysts is believed to be due to the anchor effects in Pt3Ni alloy structure, the stronger interaction between Pt3Ni alloy nanoparticles and FMWCNTs, and the "π sites" anchoring centers for metal nanoparticles from CNTs with high graphite. © 2014 Springer-Verlag Berlin Heidelberg. Source

Xu J.,Chongqing University | Chen C.,Chongqing Medical University | Jiang X.,Chongqing University | Xu R.,Chongqing University | And 6 more authors.
Biochemical and Biophysical Research Communications | Year: 2011

Geometric features such as size and shape of the microenvironment are known to alter cell behaviors such as growth, differentiation, apoptosis, and migration. Little is known, however, about the effect of curvature on cell behaviors despite that many cells reside in curved space of tubular organs such as the bronchial airways. To address this question, we fabricated micropatterned strips that mimic airway walls with varying curvature. Then, we cultured airway smooth muscle cells (ASMCs) on these strips and investigated the cells' motility and mechanical properties using time-lapse imaging microscopy and optical magnetic twisting cytometry (OMTC). We found that both motility and mechanical properties of the ASMCs were influenced by the curvature. In particular, when the curvature increased from 0 to 1/150μm -1, the velocity of cell migration first decreased (0-1/750μm -1), and then increased (1/750-1/150μm -1). In contrast, the cell stiffness increased and then decreased. Thus, at the intermediate curvature (1/750μm -1) the ASMCs were the least motile, but most stiff. The contractility instead decreased consistently as the curvature increased. The level of F-actin, and vinculin expression within the ASMCs appeared to correlate with the contractility and motility, respectively, in relation to the curvature. These results may provide valuable insights to understanding the heterogeneity of airway constrictions in asthma as well as the developing and functioning of other tubular organs and tissue engineering. © 2011 Elsevier Inc.. Source

Qiao L.,Chongqing University | Zhou M.,Chongqing University | Li Y.,Chongqing University | Zhang A.,Chongqing University | And 5 more authors.
Journal of the Electrochemical Society | Year: 2014

An electrochemical study involving the pulse electrodeposition of platinum onto p-type silicon nanowires array in non-fluoride solution for photo enhanced electrochemical hydrogen generation is presented. Pt was deposited onto the surface of silicon nanowires array (light trapping layer) as a photocatalyst with a radial multi-layers nanocluster structure, of which the photocurrent density of hydrogen generated was increased by about 300% compared to the bare silicon nanowires array under simulated solar radiance, while the value of onset potential also positively shifted to 0.40 V. Furthermore, the impedance of Pt/silicon nanowires array was smaller than that of bare silicon nanowires array as indicated by EIS analysis. We tentatively ascribed the mechanism of enhancement to the effect of the Schottky junction at the Pt/silicon nanowires array interface. © 2014 The Electrochemical Society. All rights reserved. Source

Wan D.,Chongqing Medical University | Xue L.,Chongqing Chemical Industry Vocational College | Zhu H.,Southwest University | Zhu H.,Chongqing Engineering Research Center for Pharmacological Evaluation | Luo Y.,Chongqing Medical University
Evidence-based Complementary and Alternative Medicine | Year: 2013

To investigate the role and mechanism of catalpol on neuroprotective effects and memory enhancing effects simultaneously, neuroprotective effects of catalpol were assessed by neurological deficits score, TTC staining, and cerebral blood flow detecting. Morris water maze was employed to investigate its effects on learning and memory and then clarify its possible mechanisms relating the central cholinergic system and BDNF. Edaravone and oxiracetam were used for positive control drugs based on its different action. Results showed that catalpol and edaravone significantly facilitated neurological function recovery, reduced infarction volume, and increased cerebral blood flow in stroke mice. Catalpol and oxiracetam decreased the escape latency significantly and increased the numbers of crossing platform obviously. The levels of ACh, ChAT, and BDNF in catalpol group were increased in a dose-dependent manner, and AChE declined with a U-shaped dose-response curve. Moreover, the levels of muscarinic AChR subtypes M1 and M2 in hippocampus were considerably raised by catalpol. These results demonstrated that catalpol may be useful for neuroprotection and memory enhancement, and the mechanism may be related to the central cholinergic system. © 2013 Dong Wan et al. Source

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