Chongqing Academy of Science and Technology

Chongqing, China

Chongqing Academy of Science and Technology

Chongqing, China
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Zhang M.,China Pharmaceutical University | Zhou J.,China Pharmaceutical University | Wang L.,Chongqing Medical University | Li B.,Chongqing Academy of Science and Technology | And 4 more authors.
Biological and Pharmaceutical Bulletin | Year: 2014

Caffeic acid (3,4-dihydroxycinnamic acid, CA) has been reported to have anti-inflammatory activity in animal models. However, the mechanisms underlying the anti-inflammatory effects of CA in skin inflammation are only partially understood. The present study was designed to investigate the effects and mechanisms of CA on acute and chronic skin inflammation in mice and the effect of CA in keratinocytes in vitro. The results showed that topical treatment with CA inhibited 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced skin edema in a dose-dependent manner, leading to substantial reductions in skin thickness and tissue weight, neutrophil-mediated myeloperoxidase activity, and various histopathological indicators. The CA treatment also significantly reduced the mRNA and protein levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and IL-1β at the application site, and the TNF-α production, the TNF-α-induced IL-6 and IL-1β production, and TNF-α-induced nuclear factor-kappa B (NF-κB) activation in human keratinocytes in vitro. Furthermore, CA was effective at reducing inflammatory damage induced by chronic TPA exposure. These results demonstrate that CA has anti-inflammatory activities in both acute and chronic contact dermatitis models via blockade of the mRNA and protein synthesis of these cytokines and neutrophil-mediated myeloperoxidase activity, and can target inflammatory mediators specifically in the keratinocytes. Taken together, the present results suggest that CA might be a therapeutic agent against inflammatory skin diseases. © 2014 The Pharmaceutical Society of Japan.

Zhang D.-W.,Peking Union Medical College | He H.-Q.,Chongqing Academy of Science and Technology | Guo S.-X.,Peking Union Medical College
Analytical Biochemistry | Year: 2014

HIV-1 integrase is a key enzyme for retroviral replication. The integrase can perform a palindrome cleavage reaction. In this work, a hairpin DNA probe with a palindromic DNA sequence mimicking the HIV-1 LTR-LTR junction of the 2-LTR circles in its long stem was designed for fluorescence detection of specific restriction-like cleavage activity of HIV-1 integrase. Results showed that the designed probe could be recognized and cleaved by HIV-1 integrase. The palindrome cleavage reaction can be monitored according to the increase in fluorescent signal. The assay can be applied to real-time detection of palindrome cleavage of HIV-1 integrase with advantages of simplicity, high sensitivity, and specificity. © 2014 Elsevier Ltd. All rights reserved.

Le T.,Chongqing Normal University | Le T.,Chongqing Academy of Science and Technology | Yan P.,Xinyang Agricultural College | Xu J.,Chongqing Normal University | And 2 more authors.
Food Chemistry | Year: 2013

A rapid and sensitive lateral flow immunoassay (LFIA) based on competitive format was developed and validated for simultaneous detection of cyromazine (CA) and melamine (MA) in foods of animal origin. With this method, the cut-off value for the two test lines were achieved at 25 ng/g, which was lower than the maximum residue levels (MRLs) established for CA and MA. At three fortified levels (50, 100, and 150 ng/g), the recoveries for CA and MA ranged from 73.9% to 104.2% with the relative standard deviation (RSD) less than 11.9%, based on within day and interday analysis. The lower detection limit for CA and MA in matrix sample were 0.22 ng/ml and 0.26 ng/ml, respectively, which were lower than those of published literatures. A parallel analysis of CA and MA in real samples conducted by HPLC showed comparable results to those obtained from LFIA. The results of LFIA were in good agreement with those of high performance liquid chromatography (HPLC) in the analysis of CA and MA in foods of animal origin, demonstrating the practical applicability of the developed assay in real samples. Overall, to our knowledge, this is the first report of quantitative or semi-quantitative simultaneous detection for CA and MA by immunochromatographic assay. © 2012 Elsevier Ltd. All rights reserved.

Zeng J.-B.,Southwest University | Li K.-A.,Southwest University | Du A.-K.,Chongqing Academy of Science and Technology
RSC Advances | Year: 2015

Poly(lactic acid) (PLA) is regarded as one of the most promising bio-based and biodegradable polymers, due to its excellent biodegradability, biocompatibility, renewability, high strength, and easy processibility. However, disadvantages such as brittleness and relatively high cost have restricted its applications significantly. Polymer blending provides an economic and efficient way to modify the properties of PLA. Most shortcomings of PLA are theoretically surmountable by blending with abundant polymers with various properties. But, unfortunately, PLA is thermodynamically immiscible with most existing polymers. High-performance PLA-based blends are usually unanticipated by direct blending. In order to obtain PLA-based blends with excellent overall properties, compatibilization is required during polymer blending. Various strategies have been employed or developed to compatibilize PLA blends with different polymers, as reported in recent studies. This article aims to review the development in compatibilization strategies employed in PLA-based blends. © 2015 The Royal Society of Chemistry.

Song B.,Southwest University | Song B.,Chongqing University | Guo N.,Southwest University | Guo N.,Chongqing University | And 4 more authors.
Materials and Design | Year: 2014

Twinning can generate the change of texture and a large of twin boundaries, which can greatly influence the mechanical properties of magnesium alloys. Thus, pre-twinning can be considered to be a simple and feasible method to improve the mechanical properties of magnesium alloys. Recently, some studies have confirmed that pre-twinning can be an effective way to enhance the strength, formability and mechanical anisotropy of magnesium alloys. Based on these results, some aspects of the present research on the improvement of mechanical properties via pre-twinning are reviewed. The relevant mechanisms have been summarized. Finally, for this research field, a few critical scientific problems are also proposed. © 2014 Elsevier Ltd.

Rashad M.,Chongqing University | Pan F.,Chongqing University | Pan F.,Chongqing Academy of Science and Technology | Tang A.,Chongqing University | And 2 more authors.
Journal of Alloys and Compounds | Year: 2014

Graphene nanoplatelets (GNPs) are novel reinforcing fillers due to their fascinating mechanical properties. However, their unique mechanical properties rapidly devolve as the sheets aggregate due to strong van der Waals forces and π-π attractions, therefore limiting their applications in metal matrix composites. In present work, the rapid aggregation of two-dimensional GNPs is inhibited by intercalating one-dimensional multi-walled carbon nanotubes (MW-CNTs). The long and flexible MW-CNTs bridge adjacent GNPs to form three dimensional hybrid structures which prevent their aggregation, thus resulting in a high contact area between CNTs + GNPs hybrid structure and the matrix. The composite reinforced with hybrid (GNPs and CNTs) reinforcement exhibited higher failure strain than those reinforced with individual GNPs and MW-CNTs. Compared to pure Mg, the Mg-1Al-0.6 wt.%(CNTs + GNPs) composite exhibited improvement in elastic modulus, 0.2% yield strength, ultimate tensile strength and failure strain (+17%; +19%; +15% and +137%, respectively). The impressive increase in tensile failure strain (%) confirmed significant synergetic effect between GNPs and MW-CNTs. © 2014 Elsevier B.V. All rights reserved.

Zhang H.,Chongqing University | Huang G.,Chongqing University | Huang G.,Chongqing Academy of Science and Technology | Wang L.,Chongqing University | Li J.,Chongqing University
Scripta Materialia | Year: 2012

Pre-stretching and annealing treatment was carried out to modify the microstructure of Mg-3Al-1Zn (AZ31) alloy to enhance its formability. The pre-stretched and annealed specimens exhibited lower basal texture intensities and coarser grain sizes and their Erichsen values were increased up to 65% compared with the as-received sheet. The microstructure, macrotexture, mechanical properties and formability of specimens before and after pre-stretching followed by annealing were characterized and compared. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Chen X.,Chongqing University | Liu L.,Chongqing University | Liu J.,Chongqing University | Pan F.,Chongqing University | Pan F.,Chongqing Academy of Science and Technology
Materials and Design | Year: 2015

The results indicated that addition of Y brought about the formation of I-phase (Mg3Zn6Y) and W-phase (Mg3Zn3Y2) and refined grains in as-cast state. After hot extrusion, there was more and more broken particles dispersing in matrix when Y content ranged from 0 to 3.19wt.%. With increasing Y content, EMI SE was enhanced significantly in extruded state. The alloy with 1.9wt.% Y exhibited the optimal EMI shielding capacity with the SE value of 79-118dB. It was found that good mechanical properties could be achieved by adding very low Y content. The extruded alloy with 0.5wt.% Y presented higher yield strength (268MPa), ultimate tensile strength (334MPa) and good elongation (δ=12.3%) compared with other extruded alloys. A subsequent aging treatment on the extruded alloy with 1.29wt.% Y exhibiting outstanding comprehensive EMI SE and mechanical properties resulted in precipitation of W, β1' and β2' phases, which led to further improvement in EMI SE. The peak-aged sample showed the superior mechanical properties. Based on the microstructure observation, the changes of EMI shielding capacity and mechanical properties have been discussed. © 2014 Elsevier Ltd.

Tang A.,Chongqing University | Zhang D.-F.,Chongqing University | Yang L.,Chongqing Academy of Science and Technology
Journal of Luminescence | Year: 2012

The red-emitting phosphor In 2(MoO 4) 3:Eu 3+ with cubic crystal structure was synthesized by a conventional solid-state reaction technique and its photoluminescence properties were investigated. The prepared phosphor can be efficiently excited by ultraviolet (395 nm) and blue (466 nm) light. The emission spectra of the phosphor manifest intensive red-emitting lines at 612 nm due to the electric dipole 5D 0→ 7F 2 transitions of Eu 3+. The chromaticity coordinates of x=0.63, y=0.35 (λ ex=395 nm) and x=0.60, y=0.38 (λ ex=466 nm) are close to the standard of National Television Standard Committee values (NTSC) values. The concentration quenching of In 2(MoO 4) 3:Eu 3+ is 40 mol% and the concentration self-quenching mechanism under 466 nm excitation was the dd intereaction. As a result of the strong emission intensity and good excitation, the phosphor In 2(MoO 4) 3:Eu 3+ is regarded as a promising red-emitting conversion material for white LEDs.

Dong H.,Chongqing University | Dong H.,Chongqing Academy of Science and Technology | Pan F.,Chongqing University | Pan F.,Chongqing Academy of Science and Technology | And 3 more authors.
Materials and Design | Year: 2014

Mg-5Li-2Zn dual phase alloy was prepared and extruded with ratios of 10, 25 and 79. Microstructures were acquired, and Vickers hardness was examined as well as tensile and compressive properties. The results showed that the alloy possessed a low fraction of β-Li phase besides α-Mg phase. The increase of the extrusion ratio decreased the widths of both phases and also the grain size of α-Mg phase, while increased the homogeneity of the extruded alloys. The strengths were almost the same after the alloy was extruded with ratios of 10 and 25, and the alloy extruded with the ratio of 79 presented a higher strength and a lower ductility. Serrated flow appeared during the tension of the alloy extruded with the ratio of 10. In both tensile and compressive strain-stress curves, yield plateaus were more and more invisible with the increase of the extrusion ratio. It seemed that the deforming behavior of the duplex Mg-5Li-2Zn alloy is still of the pattern of hexagonal Mg alloy with little effect of β-Li phase because of its low fraction. © 2013 Elsevier Ltd.

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