Guoqing Ying

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Oligosaccharides were obtained from agar by enzymatic hydrolysis. Activated carbon adsorption separation was used to extract oligosaccharides, and gel chromatography separation was applied to further purify oligosaccharides. The result showed that activated carbon adsorption could remove the most salt impurities, and gel column chromatography could give the(More)
Thymic stromal lymphopoietin (TSLP) is an interleukin 7-like cytokine produced mainly by epithelial cells. Many studies indicate that TSLP contributes to promote T helper (Th) 2 immune responses which are associated with the pathogenesis of allergic inflammatory diseases. Base on the cross-talk between Th2 inflammation and cancers, we will highlight the(More)
Cucurbitacin B (CuB) and its glycoside, cucurbitacin B 2-o-β-D-glucoside (CuBg), abundantly occur in the pedicels of Cucumis melo. Compared with CuB, CuBg is not efficiently extracted from the pedicels. Furthermore, the anticancer activity of CuBg is lower than that of the aglycone. A process for CuBg biotransformation to CuB was developed for the first(More)
Immunoglobulin G (IgG) antibodies are used extensively for analytical, diagnostic, and therapeutic applications. However, there are some disadvantages to purify IgG antibodies by protein A and G affinity chromatography. Therefore, it is necessary to find an effective alternative and nonchromatographic method to purify IgG. Dextran microparticles were(More)
An electrochemical biosensor that used an aptamer as a biological element was constructed to detect endotoxin. Biolayer interferometry was used to obtain the affinity constant of an aptamer for lipopolysaccharide, which had an equilibrium dissociation constant of 22.9 nM. The amine-terminated aptamer was then assembled on a gold electrode surface using(More)
Anti-HBcAg monoclonal antibodies from mouse ascites were purified by using immobilized metal ion affinity chromatography. We optimized the conditions of sample loading and elution. The results showed that when the pH stepwise elution was used, the best solution for sample loading was 20 mmol/L phosphate buffer containing 0.5 mol/L sodium chloride at pH 8.0(More)
Human thymic stromal lymphopoietin (hTSLP) protein plays a central role in inflammation. Characterizing properties of hTSLP requires a recombinant overexpression system that produces correctly folded, active hTSLP. In this report, an efficient overexpression system for the production of hTSLP was developed. We constructed expression plasmids of the(More)
To select aptamers for endotoxin separation from a 75-nucleotide single-stranded DNA random library using systematic evolution of ligands by exponential enrichment. After 15 rounds of selection, the final pool of aptamers was specific to endotoxin. Structural analysis of aptamers that appeared more than once suggested that one aptamer can form a G-quartet(More)
Monoclonal antibodies (McAbs) against chloramphenicol (CAP) were produced to detect CAP residues, which could be toxic and possesses a potential threat to human health. The CAP-BSA conjugate was obtained by bovine serum albumin (BSA) coupled with CAP, and used to immunize the mice. The splenocytes from the immunized mice were fused with mouse myeloma cells(More)
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