Publications by authors named "Saijing Zheng"

Comparison of the excitability of four different alkaloids/salts, including nicotine, nicotinic benzoate, caffeine and arecoline hydrobromide. Based on positron emission tomography (PET) imaging and F-Fallypride, a novel technique for measuring alkaloid/salt excitability in SD rats was developed. Different doses and types of alkaloids/salts were administered to the SD rats in a single nebulised inhalation.

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Exosomes are small membrane vesicles that are released by cells into the extracellular environment. Tumor-associated exosomes (TAEs) are extracellular vesicles that play a significant role in cancer progression by mediating intercellular communication and contributing to various hallmarks of cancer. These vesicles carry a cargo of proteins, lipids, nucleic acids, and other biomolecules that can be transferred to recipient cells, modifying their behavior and promoting tumor growth, angiogenesis, immune modulation, and drug resistance.

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Environmentally persistent free radicals (EPFRs) are generated in the combustion processes of solid waste and can cause adverse influences on human health, especially lung diseases. Lung cancer is one of the most serious malignancies in recent years, which the global deaths rate is about 1.6 million every year.

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A facile and environmentally friendly surface-ion adsorption method using CeCO₃OH@C as template was demonstrated to synthesize CeO₂-LaFeO₃ perovskite composite material. The obtained composite was characterized by X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermo-gravimetric analysis and differential scanning calorimetry (TG-DSC), N₂ adsorption/desorption isotherms and X-ray photoelectron spectra (XPS) measurements. The catalytic degradation of nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was tested to evaluate catalytic activity of the CeO₂-LaFeO₃ composite.

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A new prenylated indole diketopiperazine alkaloid, cristatumin F (1), and four known metabolites, echinulin (2), dehydroechinulin (3), neoechinulin A (4) and variecolorin O (5), were isolated from the crude extract of the fungus Eurotium cristatum. The structure of 1 was elucidated primarily by NMR and MS methods. The absolute configuration of 1 was assigned using Marfey's method applied to its acid hydrolyzate.

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Acetaldehyde is regarded as a toxic mainstream cigarette smoke constituent, and measurement of acetaldehyde in complex real samples is difficult owing to its high volatility and reactivity. In this work, phenyl group-functionalized magnetic mesoporous microspheres were developed as the solid-phase extraction sorbents for enrichment and analysis of acetaldehyde in mainstream cigarette smoke. The functional magnetic microspheres were first synthesized through a facile one-pot co-condensation approach.

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Determination of the tobacco-specific nitrosamine metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its N- and O-glucuronides (NNAL-N-Gluc and NNAL-O-Gluc) is important for toxicology analysis of tobacco smoke induced carcinogenicity and the understanding of detoxification mechanisms of the carcinogenic nitrosamine in humans. But previously reported indirect measurement methods involving enzymolysis and base treatment steps were tedious and time-consuming. In this work, a direct measurement method for simultaneous determination of urinary NNAL, NNAL-N-Gluc and NNAL-O-Gluc by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in a single run was developed for the first time without the need to perform enzymatic or base hydrolysis.

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A novel modified inverse gas chromatography (IGC) method has been developed to investigate the surface properties of solid materials. On the modified IGC system, the every adjusted retention time of miscellaneous probe molecules can be rapidly calculated within only one sample injection through wisely induction a capillary column and two detectors, i.e.

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Novel organic-inorganic hybrid mesoporous materials have attracted much attention because the functional organic groups can bring these materials special properties, such as selective absorption and new catalytic properties. In this paper, two kind of bis(triethoxysilyl) organic skeleton (EtO)3Si-(CH2)3-NH-C(O)-X-C(O)-NH-(CH2)3-Si(OEt)3 (X = 1,4-benzene (BSPB), 2,5-thienyl (BSPT)) precursors were synthesized firstly. Then bridged organic-inorganic hybrid mesoporous materials were prepared by direct grafting on MCM-41.

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The tobacco-specific nitrosamine metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a valuable biomarker for human exposure to the carcinogenic nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in tobacco and tobacco smoke. In this work, an efficient and sensitive method for the analysis of NNAL in human hair was developed and validated. The hair sample was extracted by NaOH solution digestion, purified by C(18) solid-phase extraction (SPE) and molecularly imprinted solid-phase extraction, further enriched by reverse-phase ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) into 1.

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The cytochrome P450 (P450 or CYP) is involved in both detoxification and metabolic activation of many carcinogens. In order to identify the role of hepatic P450 in the mutagenesis of genotoxic carcinogens, we generated a novel hepatic P450 reductase null (HRN) gpt delta mouse model, which lacks functional hepatic P450 on a gpt delta mouse background. In this study, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was used to treat HRN gpt delta mice and control littermates.

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