Publications by authors named "Meng-Xia Xie"

Based on the joint analysis of multi-omic data and the biological experiments, we demonstrate that FOXF1 inhibits invasion and metastasis of lung adenocarcinoma cells and enhances anti-tumor immunity via regulating MFAP4/FAK signal axis in this study. The levels of FOXF1 and MFAP4 are significantly down-regulated in LUAD, and the increased levels of two genes can improve the clinical prognosis of LUAD patients. Fluorescein reporter gene determination, chromatin immunoprecipitation and gene co-expression analysis indicate that MFAP4 level is positively regulated by transcription factor FOXF1.

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KRAS promoter can form G-quadruplex structure and regulate gene transcription. The drugs which can bind with G-quadruplex of KRAS promoter may be potential remedy for treatment of cancers associated with KRAS mutation. The interaction mechanism between the G-quadruplex of KRAS promoter and three isoquinoline alkaloids (jatrorrhizine, berberine and sanguinarine) has been investigated by UV-visible, fluorescence and circular dichroism spectroscopic methods.

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A novel dual emission ratiometric fluorescence probe for determination of glucose has been developed. The reference dye fluorescence isothiocyanate (FITC) has been encapsulated in the silica nanoparticles and then the red emission CdTe QDs were grafted on the surface of the silica particles to obtain the fluorescence probe. With glucose and dopamine as substrates, the glucose level was proportional to the fluorescence ratio change of above probe caused by dopamine oxidation, which was produced via bienzyme catalysis (glucose oxidase and horseradish peroxidase).

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The biological drug of the calf-blood dialysate has various pharmacological effects. It can promote the oxygen and glucose uptake for the hypoxia cells, and has beneficial effects on the malfunction of the blood circulation and trophic disturbances in the brain, and the impairment of peripheral blood circulation. Furthermore, it is favorable to wound healing and can regulate the central nervous system.

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The establishment of approaches for the differentiation of the ink entries of seals on paper can provide evidence to authenticate the related documents and can play a key role in judicial expertise. The identification and discrimination method for 38 red ink entries of seals on paper has been investigated using laser desorption ionization mass spectrometry (LDI-MS). Six dye components for the ink pastes of seals, Scarlet powder (SP), Bronze Red C (BR), Fast Red R (FR), Basic Violet 3 (BV3), Pigment Red 22 (PR22) and Pigment Red 112 (PR112), have been identified by their LDI-MS spectra, and the results have been confirmed by electrospray ionization quadruple-time of flight mass spectrometry (QTOF-ESI-MS/MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES).

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Dummy template molecularly imprinted polymers (DMIPs) on silica gel particles for simultaneously selective recognition of nine phthalate esters have been prepared. A novel dummy template molecule with similar structural skeleton to the phthalate ester, diethyl N,N'-phthaloyl-bis(11-aminoundecanoate), has been designed and synthesized. The DMIP films were grafted on the surface of silica gel particles by a sol-gel process with 3-aminopropyltriethoxysilane (APTES) and tetramethoxysilane (TEOS) as functional monomer and cross-linker, respectively, and the obtained sorbents have been characterized by FTIR with diffuse reflectance accessory.

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An UPLC-MS/MS method for determination of ten steroid hormones in animal origin food has been developed with pretreatment of the samples by matrix solid-phase dispersion (MSPD). The MSPD conditions, including the dispersing sorbents, elution solvents, ratio of sorbent to sample and the volume of the elution solvent have been investigated and optimised, and the method has been evaluated and validated. The results showed that the developed method has satisfactory linearity between the MS/MS responses of the analytes and the concentration of the steroid hormones, and the limits of the detection can reach 0.

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The binding properties of five G-quadruplex oligonucleotides (humtel24, k-ras32, c-myc22, c-kit1 and c-kit2) with polyamines have been investigated by electrospray ionization-quadrupole time of flight mass spectrometry, circular dichroism, melting temperature, atomic force microscopy (AFM) and molecular simulation. The MS results demonstrated that the polyamines and G-quadruplex DNA can form complexes with high affinity, and one molecule of G-quadruplex DNA can combine several molecules (1-5) of polyamines. The binding affinities of the polyamines to DNA were in the order of spermine > spermidine > putrescine.

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A rapid, sensitive, and simple immunosensor has been developed for the detection of Pantoea stewartii subsp. Stewartii (Pss). This immunosensor combines magnetic relaxation switch (MRS) assay with polystyrene microparticle-induced immune multivalency enrichment system.

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Molecularly imprinted film with diphenolic acid (DPA) as dummy template molecule has been grafted on the surface of Mn-doped ZnS quantum dots (QDs) to develop a selective and sensitive sensor for rapid determination of tetrabromobisphenol A (TBBPA) in water and soils. The obtained DPA-MIP-QDs sensor has distinguished selectivity and high binding affinity to TBBPA. The fluorescence quenching fractions of the sensor presented a satisfactory linearity with the concentrations of TBBPA in the range of 0.

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Determination of the red ink entries of seals on documents can provide valuable evidences for solving related crimes, distinguishing the truth of artworks, and so establishment of nondestructive approaches would play a key role in forensic analysis and related aspects. Raman and FT-IR spectroscopy have been applied for analyzing 105 kinds of red ink entries on documents. The dye components of the ink entries were identified by FT-Raman and confocal Raman microspectroscopy, and then the ink entries were classified into four groups based on these dye components.

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A rapid, sensitive, and simple immunosensor was developed for the detection of Kanamycin (KM) in milk. This immunosensor is based on magnetic relaxation switch (MRS) assay and biotin-streptavidin system (B-SA system). The target analyte (KM) competed with those on the surface of the superparamagnetic iron oxide (SPIO) nanoparticles and hence affected the formation of SPIO aggregates.

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The interaction mechanism of 3,7-dihydroxyflavone (3,7-diHF) and human serum albumin (HSA) was investigated by fluorescence quenching, fluorescence enhancement, steady-state and time-resolved fluorescence emission and UV-vis absorption spectrometry. The binding site of 3,7-diHF on protein was determined by investigating the spectroscopic properties of 3,7-diHF-HSA complex at pH 7.4 and pH 3.

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The interaction mechanisms between isoflavones (Genistein, 3', 4', 7-trihydroxyisoflavone and Biochanin A) and different isomers of human serum albumin (HSA) were investigated by fluorescence spectroscopy. Various parameters (quenching rate constants, binding constants and number of binding sites) of isoflavones-human serum albumin complexes were calculated. The results showed that the isoflavones have only one binding site on human serum albumin, located at the Site I, and the binding constants were between 0.

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Surface molecular imprinted polymers (MIPs) on silica gel particles for highly selective recognition of tetrabromobisphenol A (TBBPA) were prepared by a sol-gel process. Diphenolic Acid (DPA) and bisphenol A (BPA), whose structures were similar to that of TBBPA were selected as dummy template molecules, and 3-aminopropyltriethoxysilane (APTES) and tetramethoxysilane (TEOS) were chosen as functional monomer and cross-linker, respectively. The obtained materials were characterized by FT-IR with diffuse reflectance accessory and the results indicated polymers were successfully grafted on the surface of silica gel supporters.

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A novel approach for identification and determination of emulsion explosives with Span-80 (sorbitol mono-oleate) as the emulsifier and their postblast residues by gas chromatography-mass spectrometry (GC-MS) has been developed. 24 kinds of emulsion explosives collected have been processed by transesterification reaction with metholic KOH solution and the emulsifier has turned into methyl esters of fatty acids. From the peak area ratios of their methyl esters, most of these emulsion explosives can be differentiated.

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Protocatechuic acid (P) and veratric acid (V) are phenolic acidic compounds and have a wide biological and pharmaceutical activities, and their interaction with biomacromolecule has been a hot topic. The interaction mechanism of P and V with fsDNA was investigated by fluorescence and UV absorption spectroscopic methods. The UV results showed that P and V have three strong absorption bands at 190-230 nm (K band), 230-270 nm (B band) and 270-310 nm (R band) respectively.

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A novel approach for differentiation and dating of red ink entries of seals on documents was developed based on ion-pairing HPLC (IP-HPLC) and GC/MS. Sixty-nine red ink pastes of seals were collected and the chromatographic conditions for separation of the dye components by IP-HPLC and the volatile additives by GC/MS in the ink entries were optimized. According to the dye components and additives, the ink entries were classified by HPLC with a multi-wavelength UV detector.

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The optimum procedures for clean up aerosols in silica solid-phase extraction (SPE) cartridge prior to the analysis of polynuclear aromatic hydrocarbons (PAHs) by gas chromatography-mass spectrum (GC-MS) in selected ion monitoring detection mode have been investigated. The silica SPE cartridge is activated by dichloromethane and hexane, and then dried up by vacuum in SPE instrument for about 5 min. The sample volume loaded on the cartridge is 3 ml and after loading the sample the cartridge was dried in vacuum for 5 min.

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A novel approach for the identification and dating of the fountain pen ink entries on paper has been established by ion-pairing high-performance liquid chromatography (IP-HPLC). Twelve black and six red fountain inks have been collected, and their ink entries have been prepared by drawing lines on paper. The chromatographic conditions for separation of their dye components after extraction with solvents were optimized.

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A novel method for simultaneous determination of 8 sulfonamide residues (sulfathiazole, sulfapyridine, sulfadiazine, sulfamerazine, sulfamonome-thoxine, sulfachloropyridazine, sulfamethoxazole, and sulfadimethoxine) in honey samples by high-performance liquid chromatography (HPLC) has been developed on the basis of precolumn derivatization with 9-fluorenylmethyl-chloroformate (FMOC-Cl). Sulfonamide residues in honey samples were extracted and purified by matrix solid-phase dispersion with C18 as the solid support. The residues were derivatized by FMOC-CI, and the FMOC-sulfonamide derivatives were further purified by solid-phase extraction with silica gel as the solid support prior to HPLC analysis.

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A novel approach for simultaneous determination of 12 sulphonamides (sulphadiazine, sulphamethazine, sulphathiazole, sulphadimethoxine, sulphamerazine, sulphapyridine, sulphamethoxazole, suphamethizole, sulphaquinoxaline, sulphameter, sulphamonomethoxine, and sulphachloropyridazine) in animal tissues (swine muscle and liver, chicken muscle, beef muscle) by HPLC with UV detection has been developed. A pre-column derivatization of the sulphonamide compounds with 9-fluorenylmethyl chloroformate (FMOC-Cl) has been proposed and the reaction conditions have been optimized. The FMOC-sulphonamide derivatives were purified by SPE with silica gel as solid support prior to HPLC separation.

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The interaction mechanism of flavonol myricetin (3,5,7,3',4',5'-hexahydroxyflavone) and human serum albumin (HSA) has been characterized by fluorescence, electronic absorption, and Fourier transform infrared (FT-IR) spectroscopic approaches and the molecular modeling method. The structural characteristics of myricetin and HSA were probed, and their binding affinities were determined under different pH conditions. The results showed that the binding abilities of the drug to protein decreased under lower pH conditions (pH 3.

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A novel approach for determination of 2-mercaptobenzimidazole (MBI) and other thyreostatic residues in animal tissues by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring mode was developed. The analytes in animal tissues (including hypothyroid, pork muscle and beef samples) were extracted by acetonitrile, and then purified by a matrix solid-phase dispersion (MSPD) procedure after the extraction residues had been dissolved in water. The thyreostatic residues were derivatized by pentafluorobenzyl bromide (PFBBr) under strong basic conditions and then N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) before GC/MS analysis.

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A novel approach for classification and dating of the black gel pen ink entries on document was developed based on ion-pairing high-performance liquid chromatography (IP-HPLC). Ninety-three black gel pens were collected and divided into two groups, dye-based and pigment-based, by preliminary solubility test. The chromatographic conditions for separation of the dye-based black gel pen inks were optimized and the dye components in inks were satisfactorily separated by using 40 mmol/L tetrabutylammonium bromide as ion-pairing reagent.

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