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Tianjin Entry Exit Inspection and Quarantine Bureau

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Li Y.,China Agricultural University | Wang A.,China Agricultural University | Bai Y.,Tianjin Entry Exit Inspection and Quarantine Bureau | Wang S.,China Agricultural University
Food Chemistry | Year: 2017

A novel solid-surface fluorescence biosensor for rapid detection of Sudan I–IV was proposed based on fluorescence resonance energy transfer (FRET). The biosensor was fabricated by immobilizing acriflavine (AY) on the eggshell membrane (ESM) with glutaraldehyde as cross-linking agent. FRET mechanism was demonstrated by using AY and Sudan dyes as donor and acceptor respectively, an efficient energy transfer in the present system was indicated by the sufficient spectral overlap integral (J) and proper Förster critical distance (R0). Under optimum conditions, the fluorescence of the AY-ESM could be efficiently quenched by Sudan I–IV and the corresponding linear range was 0.5–60 μM with the detection limits (3σ/slope) of 0.16, 0.26, 0.21 and 0.17 μM respectively. Compared to the detection of Sudan dyes in solution-state, the membrane biosensor exhibited advantages of low detection limits, high sensitivity and selectivity, as well as excellent stability. Recovery tests in spiked real samples also achieved satisfactory results. © 2017 Elsevier Ltd

Li Y.,China Agricultural University | Wang A.,China Agricultural University | Bai Y.,Tianjin Entry Exit Inspection and Quarantine Bureau | Wang S.,China Agricultural University
Journal of Separation Science | Year: 2017

The coadsorption of mixed anionic–nonionic surfactants, sodium dodecylbenzenesulfonate with Triton X-100, on the surface of eggshell membrane was investigated based on adsorption isotherms to improve the solid-phase extraction performance of eggshell membrane toward organic contaminants. Results showed that even though excess Triton X-100 might inhibit the adsorption of sodium dodecylbenzenesulfonate, a low dosage of Triton X-100 can significantly improve sodium dodecylbenzenesulfonate modification and enhance the extraction efficiency of eggshell membrane from 73.7 to 100.4% because of the formation of mixed hemimicelles. The highest recovery was achieved at 2:8 (Triton X-100/sodium dodecylbenzenesulfonate mass ratios), and multiple mechanisms involving π–π interactions, hydrophobic effect, and π–π electron donor–acceptor interactions contributed to the strong extraction affinity. When mixed, the Triton X-100 and sodium dodecylbenzenesulfonate modified eggshell membrane packed cartridge coupled with high-performance liquid chromatography was applied for the simultaneous determination of trace Sudan I–IV, and low detection limits (0.16–0.26 ng/L) were achieved with satisfactory linearity (R2 > 0.999) in 10–10 000 μg/L. For real samples, Sudan II and III in one chilli sauce sample were found at 4.3 and 1.7 μg/kg. Sudan I–IV recoveries at three spiked levels were 87.4–102.9% with precisions <6.8%. Comparison with commonly used solid-phase extraction adsorbents and methods further reflected the superiorities of the proposed adsorbent in sensitivity, retention ability, and applicability. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Zhang B.-Y.,Tianjin Nankai Hospital | Jin Z.,Tianjin Nankai Hospital | Zhao Z.,Tianjin Entry Exit Inspection and Quarantine Bureau
Biomedicine and Pharmacotherapy | Year: 2017

Background Apoptosis in vascular endothelial cells (VECs) are closely correlated to multiple endotheliocyte-related cardiovascular diseases, for example atherosclerosis. Long non-coding RNAs (lncRNAs) have been testified to play important role in regulation of VECs. The purpose of this study is to investigate the potential regulation of lncRNA long intergenic noncoding RNA 00305 (LINC00305) on hypoxia induced VECs. Methods Human umbilical vein endothelial cells (HUVECs) were respectively induced with normoxia or hypoxia (1%). Expression levels of lncRNA and miRNA were detected using RT-PCR. Proliferation ability was tested by CCK-8 assay. Apoptosis assay were performed using flow cytometry and TUNEL staining. Target miRNAs prediction was performed using bioinformatics analysis. Results LINC00305 expression was significantly up-regulated in hypoxia induce HUVECs. Gain- and loss-of-function experiments showed that LINC00305 enhanced expression suppressed the proliferation and enhanced the apoptosis of HUVECs, while LINC00305 lower-expression exerted the opposite effect. Bioinformatics analysis revealed that miR-136 targeted LINC00305 art 3′-UTR. Moreover, rescue experiment confirmed the reversing function of miR-136 to LINC00305 on HUVECs proliferation and apoptosis. Conclusion Our study revealed the apoptosis-promoting role of LINC00305 in hypoxia-induced HUVECs via acting as miR-136 sponge, suggesting the vital function of lncRNAs on VECs apoptosis. © 2017

Zhao P.,Tianjin University of Technology | Shen J.,Tianjin University of Technology | Zhang H.,Tianjin Entry Exit Inspection and Quarantine Bureau
Materials Science Forum | Year: 2016

P91 heat-resistant steel is widely used in the high temperature of piping components of thermal power plants and nuclear power plants. In these conditions, the typical failure of P91 is mainly caused by creep at low stress. In this investigation the short-term creep behavior in P91 at low stress was investigated by helicoid spring creep test due to its high strain-sensitivity. The helicoid spring creep was based on the assumption of pure torsion. The mechanics field was firstly studied by ANSYS finite-element simulation to find the establishing conditions of pure torsion. Secondly, the creep properties of P91 were studied under the conditions of the temperatures of 0.38Tm

Fan M.,Jiangnan University | Zhang P.,Jiangnan University | Zhang Y.,Tianjin Entry Exit Inspection and Quarantine Bureau
Chemical Engineering Communications | Year: 2011

The catalytic synthesis of dipropyl carbonate (DPC) from transesterification of dimethyl carbonate and propyl alcohol over NaY zeolite-supported potassium salt catalysts was investigated at atmospheric pressure. K2CO3/NaY and KOH/NaY catalysts exhibited better catalytic activity than other potassium salt catalysts. From infrared resonance (IR), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), it could be concluded that K2CO3/NaY and KOH/NaY catalysts showed preferable order degree of zeolite structure, which was associated with higher dispersal of the active species K2O and extraction for part of the non-framework silicon and aluminum of the system after alkali treatment. And the partial extraction of the non-framework silicon and aluminum allowed the reactants and the products to pass through the pore of the catalysts easily and facilitated catalytic performance for DPC synthesis. © Taylor & Francis Group, LLC.

Wang G.-X.,Hunan Institute of Science and Technology | Lu M.,Jingdezhen Ceramic Institute | Hou Z.-H.,Hunan Institute of Science and Technology | Li J.,Tianjin Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2013

In this work, Fe(0)-mediated single electron-living radical copolymerization of styrene (St) and acrylamide (AM) was investigated at ambient temperature in N,N-dimethylformamide using carbon tetrachloride as initiator and tetramethylethylenediamine as ligand. Kinetic studies showed that the copolymerization followed the first-order kinetics model. The resulting copolymers of St and AM possessed predetermined molecular weights and narrow molecular weight distribution, which agreed with the character of controlled/living polymerization. On the basis of Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (NMR), the monomer reactivity ratios were calculated. The amount of ligand played an important role in copolymerization. The obtained polymer was characterized by FTIR, 1H NMR, 13C NMR, and gel permeation chromatography. The living characteristics were demonstrated by chain extension experiment. © 2013 Wiley Periodicals, Inc.

Liao F.,Nankai University | Wang L.,Beijing Entry Exit Inspection and Quarantine Bureau | Wu S.,ShenYang Agricultural University | Li Y.-P.,ShenYang Agricultural University | And 5 more authors.
International Journal of Biological Sciences | Year: 2010

The complete mitochondrial genome (mitogenome) of the fall webworm, Hyphantria cunea (Lepidoptera: Arctiidae) was determined. The genome is a circular molecule 15 481 bp long. It presents a typical gene organization and order for completely sequenced lepidopteran mitogenomes, but differs from the insect ancestral type for the placement of tRNAMet. The nucleotide composition of the genome is also highly A + T biased, accounting for 80.38%, with a slightly positive AT skewness (0.010), indicating the occurrence of more As than Ts, as found in the Noctuoidea species. All protein-coding genes (PCGs) are initiated by ATN codons, except for COI, which is tentatively designated by the CGA codon as observed in other lepidopterans. Four of 13 PCGs harbor the incomplete termination codon, T or TA. All tRNAs have a typical clover-leaf structure of mitochondrial tRNAs, except for tRNASer(AGN), the DHU arm of which could not form a stable stem-loop structure. The intergenic spacer sequence between tRNASer(AGN) and ND1 also contains the ATACTAA motif, which is conserved across the Lepidoptera order. The H. cunea A+T-rich region of 357 bp is comprised of non-repetitive sequences, but harbors several features common to the Lepidoptera insects, including the motif ATAGA followed by an 18 bp poly-T stretch, a microsatellite-like (AT)8 element preceded by the ATTTA motif, an 11 bp poly-A present immediately upstream tRNAMet. The phylogenetic analyses support the view that the H. cunea is closerly related to the Lymantria dispar than Ochrogaster lunifer, and support the hypothesis that Noctuoidea (H. cunea, L. dispar, and O. lunifer) and Geometroidea (Phthonandria atrilineata) are monophyletic. However, in the phylogenetic trees based on mitogenome sequences among the lepidopteran superfamilies, Papillonoidea (Artogeia melete, Acraea issoria, and Coreana raphaelis) joined basally within the monophyly of Lepidoptera, which is different to the traditional classification. © Ivyspring International Publisher.

Xiao Y.-B.,Tianjin Entry Exit Inspection and Quarantine Bureau | Zhang M.,Tianjin Entry Exit Inspection and Quarantine Bureau | Wen H.-W.,Tianjin Entry Exit Inspection and Quarantine Bureau
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2014

A method for simultaneous determination of arsanilic, nitarsone and roxarsone (ROX) residues in foods of animal origin was developed by accelerated solvent extraction-liquid chromatography-atomic fluorescence spectrometry (ASE-LC-AFS). The ultrasound centrifugation extraction and accelerated solvent extraction were compared, and the accelerated solvent extraction conditions, namely the proportion of the extraction solvent, the extraction temperature, extraction time and extraction times, were optimized. The operating conditions of LC-AFS and the mobile phase were optimized. Under the optimal conditions, the calibration curves for ASA, NIT and ROX were linear over the concentration range of 0~2.0 mg·L-1 and their correlation coefficients were 0.9992~0.9998. The detection limits of ASA, NIT and ROX were 2.4, 7.4 and 4.1 μg·L-1 respectively. The average recoveries of ASA, NIT and ROX from two samples spiked at three levels of 0.5, 2, 5 mg·kg-1 were in the ranges of 87.1%~93.2%, 85.2%~93.9%, and 84.2%~93.7% with RSDs of 1.4%~4.6%, 1.2%~4.2%, and 1.1%~4.5%, respectively. This method possesses the merits of convenience and good repeatability, and is a feasible method for analysis of ASA, NIT and ROX in foods of animal origin.

Yulong Z.,Nankai University | Xia Z.,Tianjin Entry Exit Inspection and Quarantine Bureau | Hongwei Z.,Tianjin Entry Exit Inspection and Quarantine Bureau | Wei L.,Tianjin Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Molecular and Cellular Probes | Year: 2010

Enterobacter sakazakii is a widespread and life-threatening bacterium especially in polluted powdered infant milk formula. Several methods have been developed for detection of E. sakazakii such as physiological and biochemical methods, PCR and loop-mediated isothermal amplification. However, these procedures were disadvantages due to a long assay time, low sensitivity or the use of toxic reagents. Our method of cross-priming amplification (CPA) under isothermal conditions combined with immuno-blotting analysis made the whole detection procedure more sensitivity and lower time-consuming. A set of specific displacement primers, cross primers and testing primers were designed based on six specific sequences in E. sakazakii 16S-23S rDNA internal transcribed spacer. Under isothermal condition at 63 °C for 60 min, the specific amplification and hybridization steps were processed simultaneously. The specificity of the CPA was tested in panel of 54 different bacterial strains and 236 milk powder products. Two red signal lines were developed on the BioHelix Express strip in all of positive E. sakazakii strains, and only one signal line was demonstrated by non- E. sakazakii bacterial strains. The limit of decetion of CPA was 6.3 ± 2.7277 fg for the genomic DNA, 88 ± 8.7892 cfu/ml for pure bacterial culture, and 3.2 ± 2.0569 cfu per 100 g milk powder with pre-enrichment. The current study demonstrated that the assay method of CPA combined with immuno-blotting analysis was a specific and sensitive detection for the rapid detection of E. sakazakii. © 2010 Elsevier Ltd.

Wang S.,Tianjin University of Science and Technology | Shi J.,Tianjin University of Science and Technology | Zheng L.,Tianjin Entry Exit Inspection and Quarantine Bureau
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2012

CNTs/PLA composites were prepared by solution blending method in the presence of pristine carbon nanotubes(MWCNTs)and carboxylated carbon nanotubes(MWCNTCOOH). The dispersity of CNTs, crystallization morphology, electric conductivity and degradation were studied. The results show that MWCNTCOOH are dispersed more homogeneously in PLA than the pristine MWCNTs by SEM. POM(Polarizing Optical Microscope) results shows that the MWCNTs act as effective nucleating agents and decrease the crystal size. With the addition of a little MWCNTCOOH, the volume resistivity of the nanocomposite decreases by 7 orders of magnitude, and the degradation also increases by MWCNTCOOH.

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