Biomedical subjects

Juan Tian

Publications and source records attributed to Juan Tian.

5 recordsLinked to original sources

PubMed2026

Single-Cell Transcriptome-Wide Mendelian Randomization and Colocalization Uncover Potential Immunocytes-Related Therapeutic Targets for Obesity.

Weight-loss treatment is crucial for individuals with obesity to prevent various complications. The role of Immune cells in obesity has been recently recognized, whereas its translation into therapy requires identifying key target genes. We performed Mendelian randomization (MR) analysis to assess causal relationships between expression quantitative trait loci (eQTL) of 14 immune cells and obesity-related traits (obesity, body mass index and body fat percentage), and validated the results in colocalization analysis. For the putative causal genes identified by the MR and colocalization analyses, we conducted pathway enrichment, differential expressed gene (DEG) analysis and search of druggable evidence, and utilized a Tier system to prioritize drug targets for obesity. MR and colocalization evidence was observed for 1630 genes associated with one or more obesity-related traits, mainly expressed in CD4+ naive/central memory T cells and enriched in antigen processing and presentation pathways. Forty-one genes showed causal relationship with all three outcomes, among which 19 genes have not been reported for obesity previously. DEG analysis using single-cell RNA sequencing data of blood or adipose tissue indicated that the differential expression of UBE2Z in monocytes, ZCCHC7 in T cells, and FNBP4 in B cells between lean and obese individuals were consistent with the MR results. By searching drug-gene interaction databases, we found targeted drugs for PYGB and PRUNE1, and PYGB was the top gene ranked in the Tier system. This study provides evidence for the involvement of immune cells in obesity, and the potential cell-specific, immune-related targets for obesity treatment.

Obesity↗

PubMed2006

Unexpected fluorescence enhancement of naphthylethyl lauryl ether in coaggregation with variant aggregators.

Unexpected fluorescence enhancement has been observed during the coaggregation process between naphthylethyl lauryl ether (the fluorescence probe) and vitamin E acetate in aqueous organic binary solutions. Variant aggregators were used to study the influence of structure features on the enhancement. The experiments indicate that a long hydrophobic hydrocarbon chain is of necessity for coaggregation, and a flat group is crucial for the fluorescence enhancement. No enhancement was observed at the absence of coaggregation. The enhancement was attributed to the hindrance of rotations and prolonged life time of the probe by steric hindrance of flat groups in coaggregate. Structure features of aggregates of variant aggregators have also been discussed.

Journal Article↗

PubMed2006

Assessment of sublethal effects of clofentezine on life-table parameters in Hawthorn spider mite (Tetranychus viennensis).

A leaf disc bioassay was employed in the laboratory to assess the population responses of Tetranychus viennensis Zacher to clofentezine at three concentrations (LC(10), LC(25) and LC(50)) in three successive generations. Life-table parameters were calculated in each acaricide exposure regime and compared by jackknife procedures. Clofentezine treatments in the juvenile stages significantly delayed development of the mites, and this delay increased with increasing dose but decreased as the mites developed. Exposure to clofentezine reduced the net reproduction rate (R(0)) in a concentration-dependent manner. The LC(50) treatment had strong effects on the hatchability of eggs produced by surviving females. Hatch rate dropped from 0.83 in the untreated control to 0.51 in the third generation. When exposed to constant concentrations of clofentezine in three successive generations, the intrinsic rate of increase and R(0) of the mites decreased significantly, but they increased significantly when exposed to decreasing concentrations. Unexposed offspring of the exposed mother also displayed increases in R(0) and the jackknife procedures indicated no significant differences in R(0) between LC(10) and LC(25) offspring and their mothers vs. the control, while R(0) in unexposed LC(50) offspring was significantly higher than their mother's, but lower than that in the control. These changing patterns of r(m) reveal that acaricide effects at the population level strongly depend on the life-history characteristics of T. viennensis and the chemical mode of action.

Aging↗

PubMed2005

Size-controllable synthesis of monodispersed SnO2 nanoparticles and application in electrocatalysts.

Size-controllable tin oxide nanoparticles are prepared by heating ethylene glycol solutions containing SnCl(2) at atmospheric pressure. The particles were characterized by means of transmission electron microscopic (TEM), X-ray diffraction (XRD) studies. TEM micrographs show that the obtained material are spherical nanoparticles, the size and size distribution of which depends on the initial experimental conditions of pH value, reaction time, water concentration, and tin precursor concentration. The XRD pattern result shows that the obtained powder is SnO(2) with tetragonal crystalline structure. On the basis of UV/vis and FTIR characterization, the formation mechanism of SnO(2) nanoparticles is deduced. Moreover, the SnO(2) nanoparticles were employed to synthesize carbon-supported PtSnO(2) catalyst, and it exhibits surprisingly high promoting catalytic activity for ethanol electrooxidation.

Journal Article↗

PubMed2005

[Pharmacokinetics and metabolites of scutellarin in normal and model rats].

AIM: To investigate the pharmacokinetics and metabolites of scutellarin in normal rats and rats with thrombosis model induced by carrageenan. METHODS: Scutellarin was assayed by reverse phase high performance liquid chromatography in various plasma samples after a single dose of 36 mg x kg(-1) iv to each rat, the pharmacokinetic parameters were estimated by 3P97 program. The metabolites of scutellarin in blood were chromatographed and identified by HPLC-PDA, LC/MS/MS. RESULTS: The calibration curve was linear over the range from 0.625 to 80.0 microg x mL(-1) (r = 0.9995), the limit quantitation was 0.312 microg x mL(-1). The plasma scutellarin concentration-time curve was fitted to the open two-compartment model. In the plasma samples, the main metabolites were deduced as 4',5-dihydroxyflavonon-7-O-beta-D-glucuronopyranosyl ester (M1), scutellarin (M2), 7-methoxy-4',5-dihydroxy-flavonon (M3) and 7-methoxy4,5,6-dihydroxyflavonon (M4). CONCLUSION: The pharmacokinetic parameters of scutellarin were significantly different in normal and model rats. The metabolic pathways of scutellarin was proposed to be dehydroxylation and methylation.

Animals↗