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Zhang J.,Beijing Entry Exit Inspection and Quarantine Bureau | Shu Y.-G.,CAS Institute of Theoretical Physics
Genes and Diseases | Year: 2017

FoF1-ATPase is an active rotary motor, and generates three-ATP for each rotation. At saturated substrate concentration, the motor can achieve about 103 r.p.m, which means one motor can generate about 105 ATP molecules during 30 min. Here, we constituted a novel nanodevice with a molecular rotary motor and a “battery”, FoF1-ATPase and chromatophore, and presented a novel method of sandwich type rotary biosensor based on ε subunit with one target-to-one motor, in which one target corresponds 105 ATP molecules as detection signals during 30 min. The target such as NT-proBNP detection demonstrated that this novel nanodevice has potential to be developed into an ultrasensitive biosensor to detect low expressed targets. © 2016 Chongqing Medical University


Hou J.,China Agricultural University | Wang L.,China Agricultural University | He W.,China Agricultural University | Zhang H.,Beijing Entry Exit Inspection and Quarantine Bureau | Feng W.-H.,China Agricultural University
Virus Research | Year: 2012

Atypical porcine reproductive and respiratory syndrome (PRRS) characterized by high morbidity and mortality emerged in China in 2006. The causative agent was confirmed to be a highly pathogenic PRRS virus (HP-PRRSV). However, the pathogenesis of HP-PRRSV is still uncertain. Here, the ability of the highly pathogenic strains (HV and JX) to induce tumor necrosis factor alpha (TNF-α) was studied. Our results showed that HV and JX were weaker inducers of TNF-α than the conventional strain CH-1a. Moreover, HV infection was demonstrated to suppress extracellular signal-regulated kinase (ERK) phosphorylation at the early time points. Pharmacologic inhibition or activation of ERK revealed that TNF-α production in HV-infected macrophages was associated with the activation status of ERK. Furthermore, HV- and JX-infection could potently impair lipopolysaccharide (LPS)- and poly(I:C)-stimulated TNF-α release in a dose dependent manner whereas synergistic effects were observed at mRNA level. The observation suggested the involvement of posttranslational impact of HP-PRRSV on TNF-α production, which might be attributed to the reduced ERK1/2 phosphorylation in response to toll-like receptor (TLR)-ligation. Taken together, our results indicated that HP-PRRSV infection could impair TNF-α production by inhibiting ERK signaling pathway, which might partially contribute to the pathogenesis of HP-PRRSV. © 2012 Elsevier B.V.


Wu H.,Peking Union Medical College | Guo J.,Astrazeneca | Chen S.,Peking Union Medical College | Liu X.,Beijing Entry Exit Inspection and Quarantine Bureau | And 3 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013

Over the past few years, the applications of liquid chromatography coupled with mass spectrometry (LC-MS) in natural product analysis have been dramatically growing because of the increasingly improved separation and detection capabilities of LC-MS instruments. In particular, novel high-resolution hybrid instruments linked to ultra-high-performance LC and the hyphenations of LC-MS with other separation or analytical techniques greatly aid unequivocal identification and highly sensitive quantification of natural products at trace concentrations in complex matrices. With the aim of providing an up-to-date overview of LC-MS applications on the analysis of plant-derived compounds, papers published within the latest years (2007-2012) involving qualitative and quantitative analysis of phytochemical constituents and their metabolites are summarized in the present review. After briefly describing the general characteristics of natural products analysis, the most remarkable features of LC-MS and sample preparation techniques, the present paper mainly focuses on screening and characterization of phenols (including flavonoids), alkaloids, terpenoids, steroids, coumarins, lignans, and miscellaneous compounds in respective herbs and biological samples, as well as traditional Chinese medicine (TCM) prescriptions using tandem mass spectrometer. Chemical fingerprinting analysis using LC-MS is also described. Meanwhile, instrumental peculiarities and methodological details are accentuated. © 2012 Elsevier B.V.


Patent
Beijing Entry Exit Inspection And Quarantine Bureau, National Center for Nanosciences and Technology of China | Date: 2011-04-12

A detection method of nucleic acid is provided. The method includes: providing nucleic acid to be tested, making the nucleic acid to be tested react under asymmetric PCR conditions with a pair of primers for target nucleic acid amplification, DNA polymerase, adenine deoxyribonucleotide, guanine deoxyribonucleotide, cytosine deoxyribonucleotide and thymidine deoxyribonucleotide in a PCR buffer solution, mixing the reaction product and liquid that contains probe molecules, and judging whether the nucleic acid to be tested contains the target nucleic acid by observing the obtained mixture color or color change. A kit is also provided that can be used in the nucleic acid detection by the said method. Application of the method and the kit in inspection and quarantine is also provided. The method is a quick and easy, sensitive and a specific detection method of nucleic acid with direct observation using naked eyes. The method does not need additional equipment.


Chi Y.-N.,Beijing Institute of Technology | Shen P.-P.,Beijing Institute of Technology | Cui F.-Y.,Beijing Entry Exit Inspection and Quarantine Bureau | Lin Z.-G.,Beijing Institute of Technology | And 2 more authors.
Inorganic Chemistry | Year: 2014

Two enantiotopic 1D chain compounds, [Cu3(L1)3(H 2O)2(H2W12O40)] ·4H2O (1a,b; L1 = 2-(4,6-bis(pyridin-2-yl)pyridin-2-yl) pyridine), crystallizing in the chiral space group P212 121 were prepared and spontaneously resolved in the absence of any chiral source. Interestingly, compounds 1a,b can be prepared from a [W7O24]6- aqueous solution, [(n-C 4H9)4N]4[W10O 32], or Na10[H2W12O42], but when [H2W12O40]6- aqueous solution was the starting material, the achiral compound [CuL1] 2[H4W12O40]·5H2O (2) was obtained. When a terpyridine ligand (L2) having a coordination mode similar to that of L1 was used, the mesomeric dimer [Cu3(L2) 3(H2O)(H2W12O40)] 2·4H2O (3) was obtained from [W7O 24]6- aqueous solution or Na10[H 2W12O42], but from [H2W 12O40]6- aqueous solution only compound [Cu2(L2)2Cl2]2[W10O 32] (4) was isolated. It is notable that in compounds 1a,b and 3 the symmetry of the α-[H2W12O40]6- cluster is broken by asymmetric coordination with metal-organic units in a similar mode. As the asymmetric subunit based on a tridecorated [H 2W12O40]6- cluster can be obtained from several isopolyoxotungstate sources except for [H2W 12O40]6-, we speculate that the symmetry breaking of α-[H2W12O40]6- depends on the transformation of isopolyoxotungstates. Furthermore, during the transformation a possible reaction intermediate as the precursor for 1a,b, compound [Cu3(L1)3(H2O)3(H 4W11O38)] (5), has been presented and characterized by density functional theory (DFT) calculations. © 2014 American Chemical Society.


Chi Y.-N.,Beijing Institute of Technology | Cui F.-Y.,Beijing Entry Exit Inspection and Quarantine Bureau | Jia A.-R.,Beijing Institute of Technology | Ma X.-Y.,Beijing Institute of Technology | Hu C.-W.,Beijing Institute of Technology
CrystEngComm | Year: 2012

Four new hybrids based on the Keggin-type polyoxometalate, formulated as (Hbm) 3(PW 12O 40)·4H 2O (1) (bm = benzimidazole, which is synthesized in situ by quinoxaline), [Cu 6(qx) 9(PW 12O 40) 2] (2), [Cu 3(qx) 5(PW 12O 40)(H 2O)] (3) and [Cu 4(qx) 4(HPCu IIW 11O 39)]·1.5H 2O (4) (qx = quinoxaline), were hydrothermally synthesized and structurally characterized by routine techniques and single-crystal X-ray diffraction. In 1, the [PW 12O 40] 3- (PW12) clusters only act as counteranions and combine with the protonated organic ligand by electrostatic interactions. In 2, a 6 3 topological 2D layer is formed with the PW12 as the template. In 3, the PW12 anions link with four metal-organic chains via Cu-O weak interactions to construct a 3D framework. In 4, the Cu(ii)-substituted Keggin unit as a hexadentate inorganic ligand coordinates with four Cu(i) ions from metal-organic chains and two O atoms from neighboring POMs to form a sandwich-like 2D layer. The structure difference of compounds 1-4 reveals that the self-assembly process is pH-dependent and the Keggin-type POM plays different role in different pH conditions. © The Royal Society of Chemistry 2012.


Cheng J.,Beijing Entry Exit Inspection and Quarantine Bureau
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology | Year: 2013

To prepare the monoclonal antibodies (mAbs) against flagellin core protein of Vibrio cholerae and establish the double-antibody sandwich ELISA method for testing Vibrio cholerae from food products. BALB/c mice were immunized with flagellin extracted from Vibrio cholerae Vc75 by differential centrifugation. The splenocytes from the immunized mice were fused with Sp2/0 myeloma cells when the antibody titer in serum reached 1:32 000. The hybridoma cell lines were obtained by regular subcloning and used to generate ascites. And mAbs reacting to Vibrio cholerae flagellin were achieved by purified from the ascites. Six hybridoma cell lines stably secreting mAbs against Vibrio cholerae flagellin were taken and named VcNo.1-VcNo.6. The mAb titer in serum by indirect ELISA was 1:2 × 10(6). SDS-PAGE showed that the flagellin protein molecular weight (Mr) was 44 000 and the purity was high. Double-antibody sandwich ELISA method was set up using VcNo.6 antibody for detecting Vibrio cholerae. The sensitivity reached 10(3) CFU/mL. The ELISA method showed high specificity to Vibrio cholerae through testing 100 Vibrio cholerae (100% positive) and 101 non-Vibrio cholerae strains (100% negative). The detection limit was 1 CFU/g sample in artificial contaminated samples. The mAbs against flagellin core protein of Vibrio cholerae was successfully prepared and used to set up the double-antibody sandwich ELISA. The mAb of VcNo.6 was highly specific to Vibrio cholerae. The sensitivity of the established ELISA was as high as 10(3) CFU/mL. Moreover, it did not react to non-Vibrio cholerae strains. Therefore, the mAbs of VcNo.6 could be widely used in Vibrio cholerae detection from food samples as well as clinical samples.


Zhang L.,Beijing Entry Exit Inspection and Quarantine Bureau
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology | Year: 2013

To prepare monoclonal antibodies (mAbs) against flagellin core protein of Vibrio (V.) parahaemolyticus and establish the double-sandwich ELISA for testing V.parahaemolyticus from food products. BALB/c mice were immunized with flagellin which was extracted from V.parahaemolyticus ATCC17802 through differential centrifugation. The splenocytes from the immunized mice were fused with Sp2/0 myeloma cells in log-phase growth when the antibody titer in serum was 1:32 000. The hybridoma cell lines were screened by regular subcloning approach and used to generate ascites. And mAbs reacting to V.parahaemolyticus flagellin were obtained by purifying from the ascites. Six hybridoma cell lines secreting mAbs against V.parahaemolyticus flagellin were prepared and named VpNo.1-VpNo.6. The mAb titer in serum by indirect ELISA was 1:2×10(6);. The mAbs were subjected to Ig classes and subclasses detection and Western blotting. The Ig subclasses of these mAbs were IgG1, IgG1, IgM, IgG1, IgG2a and IgM, respectively. SDS-PAGE showed that the flagellin protein molecular weight (Mr;) was 42 000. Using VpNo.6, Double-sandwich ELISA kit was set up and applied in detecting V.parahaemolyticus, and its sensitivity was 10(3); CFU/mL. The ELISA showed VpNo.6 had a desirable specificity to V.parahaemolyticus in testing 134 V.parahaemolyticus and 74 non-V.parahaemolyticus strains. The lowest limit of detection was 21 CFU/g sample in the base-material addition test. The monoclonal antibodies against flagellin core protein of V.parahaemolyticus were successfully prepared. The double-sandwich ELISA we established using VpNo.6 mAb had a sensitivity as high as 10(3); CFU/mL. The monoclonal antibody of VpNo.6 was highly specific to V.parahaemolyticus.


Zeng J.,Beijing Entry Exit Inspection and Quarantine Bureau
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology | Year: 2013

To prepare the monoclonal antibodies (mAbs) against flagellin core protein of Vibrio (V.) vulnificus and establish the double-antibody sandwich ELISA for testing V. vulnificus from food products. BALB/c mice were immunized by flagellin which was extracted by differential centrifugation method from V. vulnificus ATCC 1.1758. The splenocytes taken from the immunized mice were fused with Sp2/0 myeloma cells when the antibody titer reached 1:32 000 in serum. The hybridoma cell lines were prepared and screened by hybridoma technique and ELISA. The cells secreting mAbs were cloned through the limited dilution. The hybridoma cell lines were used to generate ascites. The mAbs were obtained by purification from the ascites. Five hybridoma cell lines which stably secreted mAbs against flagellin were isolated and named VVNo.1-VVNo.5. The mAb titer in serum reached 1:(2×10(6);). SDS-PAGE showed that the relative molecular mass (Mr;) of flagellin protein was 44 000, and that the purity was high. Double-antibody sandwich ELISA was set up using VVNo.5 antibody, and the sensitivity reached 10(3); CFU/mL culture broth. The ELISA showed that VVNo.5 antibody was highly specific to V. vulnificus. The detection limit was 2 CFU/25 g culture broth in artificial contaminated samples. The mAbs were obtained against flagellin core protein of V. vulnificus. The double-antibody sandwich ELISA was established using VVNo.5 mAb. The monoclonal antibody of VVNo.5 was highly specific to V. vulnificus, without cross reaction with non-target bacteria. Therefore the monoclonal antibodies of VVNo.5 could be widely used in detecting V. vulnificus from food samples as well as the clinical samples.


Liu X.,CAS National Center for Nanoscience and Technology | Zhang L.,Beijing Entry Exit Inspection and Quarantine Bureau | Zeng J.,Beijing Entry Exit Inspection and Quarantine Bureau | Gao Y.,CAS National Center for Nanoscience and Technology | Tang Z.,CAS National Center for Nanoscience and Technology
Journal of Nanoparticle Research | Year: 2013

In this work, superparamagnetic nano-immunobeads (SPM-NIBs) based on conjugation of superparamagnetic Fe3O4 nanoparticles with specific antibodies have been developed toward food safety insurance. The resultant SPM-NIBs exhibits excellent colloidal stability and reversible magnetic response. Vibrio parahaemolyticus, which is a main foodborne pathogenes from contaminated seafood, can be separated specifically and efficiently by the resultant SPM-NIBs. The results of bacteria separation demonstrate that the SPM-NIBs have a higher specific activity and sensitivity toward V. parahaemolyticus. About 80 % of V. parahaemolyticus cells can be captured when the concentration of the broth reaches 103 CFU/mL. Thus, the SPM-NIBs can effectively enhance the efficiency for target bacteria inspections by shortening the period of culture time. This work holds the promise of development of general technique to prepare effective SPM-NIBs toward food safety inspections and other bio-related applications for target analyte separation and collection. © 2013 Springer Science+Business Media Dordrecht.

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