Leonurine, an active alkaloid extracted from Herba leonuri, is reported to have potent anti-inflammatory activity against rheumatoid arthritis (RA). However, the molecular mechanism of action of leonurine in RA remains poorly understood. In this study, we detected 3,425 mRNAs differentially expressed between CD4 + T cells of RA patients and those of healthy individuals using microarray raw data mining. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that transcriptional coactivator with PDZ-binding motif (TAZ) regulates a variety of biological processes including T-helper (Th)-17 cell development, and was thus selected for functional verification. In a naïve CD4 + T cell differentiation assay, we found that TAZ overexpression was associated with impaired balance between T regulatory (Treg) and Th17 cells in vitro. TAZ overexpression increased the levels of the pro-inflammatory cytokines interleukin (IL)-17, IL-1β, and tumor necrosis factor (TNF)-α and decreased that of the anti-inflammatory cytokine IL-10. Leonurine treatment had a direct recovery effect on the impaired balance and reduced the expression of TAZ and led to normalization of IL-17, IL-1β, and TNF-α and IL-10. Furthermore, IL-6 was found to promote the expression of TAZ and receptor activator of nuclear factor kappa-B ligand (RANKL), and RANK. Leonurine significantly inhibited TAZ-mediated expression of RANKL, and RANK and IL-6 in synovial fibroblasts. We conclude that the therapeutic effect of leonurine was through suppression of TAZ led to restoration of Treg/Th17 balance and suppression of synovial fibroblast action.
A kind of semi-aromatic polyamide, poly(dodecamethylene terephthalamide) (PA12T) was synthesized via a three-step reaction of terephthalic acid and 1,12-dodecanediamine. The structure of the prepared PA12T was characterized by Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance (1H-NMR). The thermal behaviour of PA12T was determined by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Melting temperature (Tm), glass transition temperature (Tg) and decomposition temperature (Td) of PA12T are 311°C, 144°C and 429°C, respectively. Isothermal crystallization kinetics of PA12T have been investigated in the temperature range of 270-280°C using DSC. The activation energies (ΔE) were determined to be -170.4 kJ/mol for the isothermal crystallization processes by the Arrhenius’ methods.
Two kinds of ABC-type miktoarm star copolymers, poly(α-methylstyrene)-poly(ethylene oxide)-poly(ethoxyethyl glycidylether) (PMS-PEO-PEEGE) and poly(α-methylstyrene)-poly(ethylene oxide)-polyglycidol (PMS-PEO-PG), were synthesized via a combination of anionic polymerization with ring-opening polymerization. Firstly, The poly(α-methyl styryl lithium) (PMS-Li+) was capped by EEGE to form the functionalized poly(α-methylstyrene) with both an active ω-hydroxyl group and an ω’-ethoxyethyl-protected hydroxyl group. Secondly, the PMS-b-PEO block copolymers, star(PMS-PEO-PEEGE) and star(PMS-PEO-PG) copolymers were obtained by the ring-opening polymerization of EO and EEGE via the variation of the functional end group, respectively. Finally, the ethoxyethyl group on the PEEGE arm was hydrolyzed. The obtained miktoarm star copolymers and intermediates were characterized by proton nuclear magnetic resonance (1H-NMR) and size exclusion chromatography (SEC).
Brown Corundum Ash(BCA) was used to modify nylon 1212(PA1212), which is produced during the production of electric fused brown corundum alumina and will causes serous environmental pollution if it is not recycled. In order to improve the tribological property of PA1212 composites, Graphite, MoS2 and PTFE were used. The composites were prepared by a twin-screw extruder through melt intercalation. The mechanical properties and the wear resistance of the PA1212/Brown Corundum Ash/graphite/MoS2/PTFE composite were studied. The shearing area of composite and the worn surfaces were examined by scanning electric microscope (SEM).
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