22 research outputs found

    Design, preparation and properties of novel flame retardant thermosetting vinyl ester copolymers based on castor oil and industrial dipentene

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    A novel bio-based flame-retardant thermosetting vinyl ester resin monomer was synthesized from castor oil. The chemical structures of the monomer was characterized by FTIR and 1H-NMR. In order to improve its rigidity and expand its application in the field of bio-based materials, it was mixed with certain proportions of another reactive bio-based VER monomer, which had rigid and strong polar groups, and then a series of copolymers were prepared with thermal curing method. Then their tensile property, hardness, morphology of fractured surface, flame retardant property, DMA and thermostability were all investigated. The results indicated that the copolymers had relatively high tensile strength of 11.2 MPa, and the limiting oxygen index is above 23% in all prepared copolymers. DMA demonstrates that the glass transition temperature of the cured resins is up to 56.1°C. Thermogravimetric analysis shows that the copolymers have excellent thermal stability

    Effects of preparation methods of mixed calcium and zinc thermal stabilizers derived from dimer fatty acid and tung-oil based C22 triacid on properties of PVC

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    Calcium and zinc salts of dimer fatty acids (DFA-Ca and DFA-Zn) were synthesized using direct neutralization and metathesis technologies, respectively. The adduct of maleic anhydride and methyl eleostearate (MAME) was also converted to the corresponding zinc soap (C22TA-Zn) and calcium soap (C22TA-Ca) by the two different synthetic routes. Mixed Ca/Zn salts between DFA-Ca and DFA-Zn, and between C22TA-Zn and C22TA-Ca were used as thermal stabilizers for poly(vinyl chloride) (PVC). The PVC thermal stability was determined using Congo red test, discoloration test, torque rheological analysis and TGA. Dynamic mechanical properties were also tested. Results indicated that the DFA-Ca/DFA-Zn thermal stabilizer from direct neutralization technology was found to be superior to that of the metathesis product. The C22TA-Ca/C22TA-Zn thermal stabilizer from direct neutralization method had overall superior thermal stability, and displayed modulus and glass transition comparable to that of metathesis product. Direct neutralization method was more excellent and convenient than metathesis technology

    Tissue Distribution of Lipoprotein Lipase (LPL) and Regulation of LPL Gene Expression Induced by Insulin and Glucose in Goose Primary Hepatocytes

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    The study was to research the gene expression of lipoprotein lipase (LPL) in abdomen adipose tissue, subcutaneous adipose tissue, pectoral muscle, skeletal muscles, liver, brain and spleen of geese, and the effect of insulin and glucose on gene expression of LPL was measured in primary hepatocytes of Sichuan white geese (Anser cygnoides) and Landes geese (Anser anser). We quantified gene expression by competitive reverse transcriptase PCR (RT-PCR). The results indicated: First, 0-150nM insulin could increase the mRNA level of LPL in a dose-dependent pattern, and 200nM insulin had an inhibiting effect. Second, there was a synergistic effect of insulin and glucose on LPL gene expression, and the synergistic effect of 30mM glucose and 50nM insulin was much higher than the single effect of insulin or glucose. In addition, the induction of LPL mRNA level by insulin and glucose was higher in Landes goose than the induction in Sichuan white goose. It was concluded that LPL was highly expressed in the goose liver, and the LPL gene level could be up-regulated by insulin and glucose

    Clerodendranthus spicatus inhibits epithelial–mesenchymal transition of renal tubular cells through the NF-κB/Snail signalling pathway in hyperuricaemia nephropathy

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    AbstractContext Clerodendranthus spicatus Thunb. (Labiatae) (CS), a perennial traditional Chinese medicinal herb that can reduce serum uric acid (sUA) levels and ameliorate renal function is widely used to treat hyperuricaemic nephropathy (HN).Objective To investigate the molecular mechanism of action of CS in HN treatment using in vivo and in vitro experiments.Materials and methods Sprague-Dawley rats were randomly divided into control, HN, CS and positive control allopurinol groups. The HN group was intraperitoneally injected with 750 mg/kg oxonic acid potassium (OA), whereas the CS group was injected with OA along with a gavage of CS (low dose 3.125 g/kg, high dose 6.25 g/kg) for five weeks. For in vitro studies, uric acid-treated HK2 cells were used to verify the therapeutic mechanism of CS in HN.Results HN rats exhibit pathological phenotypes of elevated sUA levels and renal injury. CS significantly improved these symptoms and sUA (p < 0.05) and blood urea nitrogen (p < 0.01) levels, and dramatically improved renal tubular injury in HN rats. The IC50 value of UA (uric acid) in HK2 cells was 826.32 ± 3.55 μg/mL; however, 120 ng/mL CS had no significant cytotoxicity on HK2 cells. In vivo and in vitro studies showed that CS inhibited NF-κB phosphorylation and inhibited α-smooth muscle actin (α-SMA) and vimentin expression while increasing E-cadherin expression, suggesting that CS inhibited the fibrotic process in renal cells, thus protecting renal function.Discussion and conclusions These findings provide a fundamental understanding of the application of CS in HN treatment to better guide clinical interventions

    Insulin Stimulates Goose Liver Cell Growth by Activating PI3K-AKT-mTOR Signal Pathway

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    Background/Aims: Recent studies have suggested a crucial role for PI3K-Akt-mTOR pathway in regulating cell proliferation, so we hypothesize that insulin acts goose hepatocellular growth by PI3K-Akt-mTOR signal pathway. Because the physiological status of liver cells in vitro is different from that in vivo, a simplified cell model in vitro was established. Methods: Goose primary hepatocytes were isolated and incubated in either no addition as a control or insulin or PI3K-Akt-mTOR pathway inhibitors or co-treatment with glucose and PI3K-Akt-mTOR pathway inhibitors; Then, cell DNA synthesis and cell cycle analysis were detected by BrdU-incorporation Assay and Flow cytometric analysis; the mRNA expression and protein expression of factors involved in the cell cycle were determined by Real-Time RT-PCR, ELISA, and western blot. Results: Here we first showed that insulin evidently increased the cell DNA synthesis, the mRNA level and protein content of factors involved in the cell proliferation of goose primary hepatocytes. Meanwhile, insulin evidently increased the mRNA level and protein content of factors involved in PI3K-Akt-mTOR pathway. However, the up-regulation of insulin on cell proliferation was decreased significantly by the inhibitors of PBK-Akt-mTOR pathway, LY294002, rapamycin or NVP-BEZ235. Conclusion: These findings suggest that PI3K-Akt-mTOR pathway plays an essential role in insulin-regulated cell proliferation of goose hepatocyte

    DataSheet1_SLC2A9 rs16890979 reduces uric acid absorption by kidney organoids.docx

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    Introduction: The excretion and absorption of uric acid (UA) by the kidneys helps regulate serum UA levels. GLUT9, encoded by SLC2A9, is mainly expressed in the renal tubules responsible for UA absorption. SLC2A9 polymorphisms are associated with different serum UA levels. However, the lack of proper in vitro models has stalled research on the mechanisms of single nucleotide polymorphisms (SNPs) that affect UA metabolism in human urate transporters.Methods: In this study, we constructed a gene-edited human embryonic stem cells-9 (ESC-H9) derived kidney organoid bearing rs16890979, an SLC2A9 missense mutation with undetermined associations with hyperuricemia or hypouricemia. Kidney organoids derived from ESC-H9 with genetical overexpression (OE) and low expression (shRNA) of SLC2A9 to serve as controls to study the function of SLC2A9. The function of rs16890979 on UA metabolism was evaluated after placing the organoids to urate-containing medium and following histopathological analysis.Results: The kidney organoids with heterozygous or homozygous rs16890979 mutations showed normal SLC2A9 expression levels and histological distribution, phenotypically similar to the wild-type controls. However, reduced absorption of UA by the kidney organoids with rs16890979 mutants was observed. This finding together with the observation that UA absorption is increased in organoids with SLC2A9 overexpression and decreased in those with SLC2A9 knockdown, suggest that GLUT9 is responsible for UA absorption, and the rs16890979 SNP may compromise this functionality. Moreover, epithelial-mesenchymal transition (EMT) was detected in organoids after UA treatment, especially in the kidney organoid carrying GLUT9OE, suggesting the cytobiological mechanism explaining the pathological features in hyperuricosuria-related renal injury.Discussion: This study showing the transitional value of kidney organoid modeling the function of SNPs on UA metabolism. With a defined genetic background and a confirmed UA absorption function should be useful for studies on renal histological, cellular, and molecular mechanisms with this organoid model.</p

    Effect of insulin on lipid deposition.

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    <p><b>A</b>, intracellular TG concentrations. <b>B</b>, extracellular TG concentrations. <b>C</b>, extracellular VLDL concentrations. <b>D</b>, Lipid contents were measured by Oil Red O extraction and are shown in optical density value units. <b>E</b>, intracellular lipid accumulation measured by Oil Red O staining; the cells were examined by phase contrast microscopy at 40Ă— magnification.</p

    Treatment with rapamycin blocked the effect of insulin on lipid accumulation.

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    <p><b>A</b>, intracellular TG concentrations. <b>B</b>, extracellular TG concentrations. <b>C</b>, extracellular VLDL concentrations. <b>D</b>, Lipid contents were measured by Oil Red O extraction and are shown in optical density value units. <b>E</b>, Protein levels of genes involved in lipid metabolism; FAS levels are shown in nmol/ml, whereas ACCα and CPT1 levels are shown in ng/ml. * indicate significant differences among treatments (P <0.05).</p
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