Molecular dynamics study on structural modulation and dyeing property optimization of meta-aramid in a DMSO/electrolyte system.

Meta-aramid (PMIA) fabrics are typically problematic to dye owing to their extremely crystalline structure and high compactness. Herein, Dimethyl sulfoxide (DMSO) and electrolyte as hydrogen bond regulators were selected to improve the dyeability of PIMA dyed with cationic dyes. The PMIA shows both high dyeing and mechanical properties as a result of the synergistic effect of DMSO and electrolyte in the system, which destructs hydrogen bonding networks and increase interaction energy density between dye molecules and PMIA, confirmed by a series of characterization and molecular dynamics simulations. In the DMSO/NaCl/PMIA system, while maintaining excellent mechanical (breaking strength and elongation at break of 24.6Mpa and 37.6 %, respectively) and thermal properties, PMIA not only obtained the best dyeability, increasing the Dye uptake from 20 % to 70.62 % and the K/S value from 2.92 to 18.02, but also achieved excellent colour fastness (fastness to dry and wet rubbing, fastness to light, and fastness to washing of 4-5, 3-4, 3-4 and 4-5, respectively). Simulated results and experimental data verified that the DMSO/NaCl system optimally synergizes hydrogen bond regulation for PMIA and achieves the best dyeing effects for cationic dyes, manifesting its great potential in the PMIA wearability area.

The protective effect of umbelliferone ameliorates myocardial injury following ischemia­reperfusion in the rat through suppression NLRP3 inflammasome and upregulating the PPAR-γ.

The present study investigated whether the protective effect of umbelliferone could regulate myocardial injury following ischemia­reperfusion and improve mitochondrial respiratory function, thereby relieving myocardial injury following ischemia­reperfusion in rats. In the present study, the extent of inflammation and oxidative stress were analyzed using ELISA. Western blot analysis was employed to investigate the protein expression levels of the PYD domains­containing protein 3 (NLRP3) inflammasome and peroxisome proliferator­activated receptor-γ (PPAR­Î³). Compared with the myocardial injury following ischemia­reperfusion group, umbelliferone significantly prevented myocardial injury, inhibited oxidative stress markers (superoxide dismutase and malondialdehyde), reduced inflammation (tumor necrosis factor­α and interleukin­6) and myocardial apoptosis levels (caspase­3/9 and apoptosis regular B­cell lymphoma­2­associated X protein) in the myocardial injury following ischemia­reperfusion group of rats. Umbelliferone treatment also suppressed NACHT, LRR and NLRP3 inflammasome activation and induced PPAR­Î³ expression. The results of the present study suggested that the protective effect of umbelliferone may ameliorate myocardial injury following ischemia­reperfusion in the rat through the suppression of the NLRP3 inflammasome and upregulating PPAR­Î³ expression.