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Liang M.,Tianjin University | Su R.,Tianjin University | Qi W.,Tianjin University | Yu Y.,Tianjin University | And 2 more authors.
Journal of Materials Science | Year: 2014

A novel functional bio-nanocomposite was prepared by deposition of Ag nanoparticles onto the surface of natural eggshell membrane fibers. Practically, the functional groups exposed on the fiber surface can provide locations to anchor Ag ions when immersed into metal precursor solution. The synthesized small-sized Ag nanoparticles with uniform distribution is well decorated on the surface of interwoven fibers of eggshell membrane. The effectiveness of the as-prepared AgNPs/ESM composites as a solid phase heterogeneous catalyst has been evaluated, for the first time, on the well-known 4-nitrophenol reduction to 4-aminophenol in the presence of excess borohydride. Moreover, the kinetics of the reduction reaction was investigated at different temperatures to determine the activation energy. This work provides an important example in the introduction of natural membranes for the fabrication of functional hybrid nanocomposites which could be very useful in varying fields. © 2013 Springer Science+Business Media New York.

Yu Y.,Tianjin University | Su R.,Tianjin University | Wang L.,Hunan Entry Exit Inspection and Quarantine Bureau | Qi W.,Tianjin University | He Z.,Tianjin University
Medicinal Chemistry Research | Year: 2010

Dibenzo [c,h]-[1,6] naphthyridin-6-one (ARC-111) and its analogues can exhibit potent topoisomerase I targeting and antitumor activities. Quantitative structure-activity relationship (QSAR) studies on the antitumor activity of 22 ARC-111 analogues to RPMI 8402 (expressed as pIC50) were performed by using electronic, spatial, thermodynamic, and topological descriptors based on different chemometric tools including stepwise multiple linear regression (stepwise MLR), partial least squares (PLS), and artificial neural network (ANN). QSAR equations were examined using a training set of 18 compounds and an external test set of four compounds, which was divided by cluster analysis. The ANN model was the most powerful, with a square of predictive correlation coefficient R pred 2 of 0.963 for the test set; the R pred 2 values for stepwise MLR and PLS were 0.780 and 0.729, respectively. The results obtained with these models indicated that the antitumor activity of ARC-111 analogues depends strongly on electronic factors (such as sum of E-state of H-bond acceptors, dipole moment as debyes, and total energy). © 2009 Birkhäuser Boston.

Liang M.,Tianjin University | Wang L.,Hunan Entry Exit Inspection and Quarantine Bureau | Su R.,Tianjin University | Qi W.,Tianjin University | And 3 more authors.
Catalysis Science and Technology | Year: 2013

For the first time, we demonstrated the fabrication of silver nanoparticles (NPs) in cross-linked protein crystal hybrid material with catalytic properties using a facile chemical reduction method. The macroscopic porous lysozyme crystals can be used as excellent templates for the incorporation of Ag nanoparticles. The resulting AgNP-in-lysozyme crystal composites exhibited a good catalytic activity toward nitrophenol reduction. Notably, these catalysts could be easily recovered and reused for at least five successive cycles with almost constant activity and conversion efficiency. This journal is © 2013 The Royal Society of Chemistry.

Liang M.,Tianjin University | Liu R.,Tianjin University | Qi W.,Tianjin University | Su R.,Tianjin University | And 3 more authors.
Food Chemistry | Year: 2013

The interaction of procyanidins with proteins has aroused extensive attention due to its important relationship with the bioavailability and astringent property of polyphenols. In the present work, we have investigated the interactions of lysozyme with procyanidin dimer (B3) using various biophysical approaches, which aims to provide insights into the mechanism of protein/polyphenol aggregation. Procyanidin B3 spontaneously binds lysozyme, inducing the multilevel structural changes in lysozyme and the formation of insoluble complexes. The relationship between lysozyme aggregation and the loss of enzymatic activity was monitored using dynamic light scattering and fluorescence quenching. The influences of two carbohydrates (gum arabic and sucrose) on lysozyme/B3 aggregation were also studied. Gum arabic effectively inhibited the formation of insoluble aggregates, but was unable to restore the fluorescence and activity of lysozyme. However, sucrose concomitantly decreased the aggregate size with the recovery of fluorescence and lysozyme activity. These results proposed two probable mechanisms by which these two carbohydrates inhibit protein/polyphenol aggregation. © 2012 Elsevier Ltd. All rights reserved.

Wang G.M.,Chongqing University | Dai H.,Hunan Entry Exit Inspection and Quarantine Bureau | Li Y.G.,Chongqing University | Li X.L.,Chongqing Entry Exit Inspection and Quarantine Bureau | And 4 more authors.
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2010

Trichlorfon is a thermally unstable insecticide that can be easily decomposed to dichlorvos at high temperatures. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of the residues of trichlorfon and dichlorvos in animal tissues. Trichlorfon and dichlorvos in animal tissues were extracted with dichloromethane, homogenized/shaken, concentrated, and determined by LC-MS/MS. The two insecticides can be effectively separated and individually determined. The limits of detection (LODs) of trichlorfon and dichlorvos were 0.04 and 0.07mg kg 1, respectively; the limits of quantification (LOQs) of the two insecticides were both 5 mgkg 1. The average recoveries for three spiked blank samples at 10,20 and 40mg kg 1 were in the range 85-106%, with relative standard deviations (RSDs) below 10.6%, which falls in a reasonable range for the analysis of the two insecticides in animal-derived foods. The method is fit-for-purpose for the simultaneous determination of residues of trichlorfon and dichlorvos in animal tissues. © 2010 Taylor & Francis.

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