Enhancing the flame retardancy and UV resistance of polyamide 6 by introducing ternary supramolecular aggregates.

An integrated multi-functional additive was fabricated by successively grafting melamine (MEL) and phytic acid (PhA) on multiwalled carbon-nanotubes (MWNCTs), and was then applied in PA6 to improve the flame retardancy and light aging resistance of the composite. The limit oxygen index of PA6 composite containing 7 wt% PhA-MEL-MWCNTs was increased to 26.4 from 21.0. The smoke and CO release were significantly reduced by 48% and 88% respectively, and the severe melt dripping of PA6 in burning was eliminated. It is proved that PhA-MEL-MWCNTs can absorb ultraviolet (UV) radiation, and hence significantly reduces the mechanical property loss of the PA6 composite after UV aging. The tensile strength of the aged PA6/7 wt%PhA-MEL-MWCNTs composite sample only decreased by 18.1%, which was significantly lower than the loss rate of the control aged PA6 sample (62.5%). This protocol provides a new opportunity for fabricating long-life flame retardant polyamide composites.

The protective effects of exenatide against AGEs-induced articular matrix degradation in human primary chondrocytes.

Osteoarthritis (OA) presents a major global health burden and is projected to become even more prevalent in coming decades. Therefore, it is of utmost importance to uncover novel therapies for the treatment and prevention of this disease. In the present study, we investigated the effects of exenatide, a specific glucagon-like peptide (GLP) agonist, on degradation of type II collagen and aggrecan, the two main components of the articular extracellular matrix, in human primary chondrocytes. Our results reveal that exenatide could ameliorate degradation of type II collagen and aggrecan by inhibiting expression of metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) induced by advanced glycation end-products. We also found that exenatide reduces oxidative stress and inhibits activation of nuclear factor-κB through the p38 cellular signaling pathway. Taken together, the findings of this study indicate that exenatide may have potential as a novel treatment for osteoarthritis.

Risk of bleeding in patients with continued dual antiplatelet therapy during orthopedic surgery.

BACKGROUND: To prevent risk of life-threatening stent thrombosis, all patients need to undergo dual antiplatelet therapy (DAPT) for at least 6 weeks to 12 months after stent implantation. If DAPT is continued during noncardiac surgery, there is a risk of severe bleeding at the surgical site. Our study was to assess the risk of bleeding in patients with continued DAPT during orthopedic surgery. METHODS: The clinical data of 78 patients with coronary heart disease who underwent orthopedic surgery from February 2006 to July 2018 were retrospectively analyzed. Prior to orthopedic surgery, DAPT was continued in 16 patients (group I), 24 patients were treated with single antiplatelet therapy (group II), and 26 patients received low-molecular-weight heparin therapy for more than 5 days after the discontinuation of all antiplatelet therapies (group III). Twelve patients were excluded, as they had undergone minimally invasive surgery such as transforaminal endoscopy and vertebroplasty. The perioperative blood loss of each patient was calculated using Nadler's formula and Gross' formula. The intraoperative bleeding volume, total volume of intraoperative bleeding in addition to postoperative drainage, and total blood loss were compared between groups. The level of significance was set at P < 0.05. RESULTS: There were no significant differences between the three groups in age, intraoperative bleeding volume, total volume of intraoperative bleeding in addition to postoperative drainage, and total perioperative blood loss calculated by Nadler's formula and Gross' formula (all P > 0.05). Six patients experienced postoperative cardiovascular complications due to the delayed restart of antiplatelet therapy; one of these patients in group III died from myocardial infarction. CONCLUSIONS: Continued DAPT or single antiplatelet treatment during orthopedic surgery does not increase the total intraoperative and perioperative bleeding compared with switching from antiplatelet therapy to low-molecular-weight heparin. However, the discontinuation of antiplatelet therapy increases the risk of serious cardiac complications.