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Zinc-neutralized sulfonated EPDM ionomers (Zn-SEPDM) were prepared by batch and continuous melt sulfonation processes, and the ionomer products were compared with ionomers synthesized by sulfonation of EPDM in homogeneous solution. The efficiency of a batch melt sulfonation using an intensive mixer as a reactor was comparable to that of the solution sulfonation process, but the efficiency of the melt sulfonation in a twin-screw extruder was considerably lower, which was thought to be a consequence of a relatively short reaction residence time due to limitations of the equipment. Melt neutralization was not complete, which produced a dark colored product. However, the incomplete neutralization and the color of the product did not affect the mechanical properties of the melt sulfonated ionomers, which were comparable to those of ionomers made by conventional solution sulfonation. The metal sulfonate concentration alone determined the mechanical properties of the ionomer. Melt sulfonation of Zn-SEPDM ionomers by batch or continuous melt processes appears to be a practical alternative to solution sulfonation, but further optimization of the melt sulfonation processes is needed to ensure uniform sulfonation and complete neutralization. KEYWORDS elastomers, ionomers, mechanical properties, reactive processing, 1 | INTRODUCTION Ionomers are polymers that contain a modest amount of bonded ionic groups that modify the physical, mechanical and rheological properties of the parent non-ionic polymer, [1,2] Although [...]

Objective To investigate the expression and function of the TNF signaling pathway in the early stage of orthodontic tooth movement with periodontitis and to provide evidence to study the early inflammatory response in patients with periodontitis orthodontic treatment. Methods Sixteen SD rats were randomly divided into four groups: group A--12 h of orthodontic tooth movement of the bilateral maxillary first molars in rats with periodontitis; group B--periodontitis model of the bilateral maxillary first molars without orthodontic tooth movement; group C--12 h of orthodontic tooth movement of the same teeth in rats with healthy periodontium; group D--control group without operations. The bilateral maxillary first molars and surrounding periodontal tissue of each group were collected for gene chip detection. Pathway enrichment analysis, qRT-PCR and GO (gene ontology) analysis were performed to identify differential genes involved in the TNF signaling pathway. Results Gene chip results showed that the TNF signaling pathway was significantly upregulated in group A, group B and group C (P group B > group C (P

Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) is a widely expressed membrane glycoprotein that acts as an important modulator of lipid metabolism and inflammatory stress. N -glycosylation of SCAP has been suggested to modulate cancer development, but its role in nonalcoholic steatohepatitis (NASH) is poorly understood. In this study, the N -glycosylation of SCAP was analyzed by using sequential trypsin proteolysis and glycosidase treatment. The liver cell lines expressing wild-type and N- glycosylation sites mutated SCAP were constructed to investigate the N- glycosylation role of SCAP in regulating inflammation and lipid accumulation as well as the underlying mechanisms. The hepatic SCAP protein levels were significantly increased in C57BL/6J mice fed with Western diet and sugar water (WD + SW) and diabetic db/db mice, which exhibited typical liver steatosis and inflammation accompanied with hyperglycemia. In vitro, the enhanced N- glycosylation by high glucose increased the protein stability of SCAP and hence increased its total protein levels, whereas the ablation of N- glycosylation significantly decreased SCAP protein stability and alleviated lipid accumulation and inflammation in hepatic cell lines. Mechanistically, SCAP N- glycosylation increased not only the SREBP-1-mediated acetyl-CoA synthetase 2 (ACSS2) transcription but also the AMPK-mediated S659 phosphorylation of ACCS2 protein, causing the enhanced ACSS2 levels in nucleus and hence increasing the histone H3K27 acetylation (H3K27ac), which is a key epigenetic modification associated with NASH. Modulating ACSS2 expression or its location in the nuclear abolished the effects of SCAP N- glycosylation on H3K27ac and lipid accumulation and inflammation. In conclusion, SCAP N- glycosylation aggravates inflammation and lipid accumulation through enhancing ACSS2-mediated H3K27ac in hepatocytes. NEW & NOTEWORTHY N- glycosylation of SCAP exacerbates inflammation and lipid accumulation in hepatocytes through ACSS2-mediated H3K27ac. Our data suggest that SCAP N- glycosylation plays a key role in regulating histone H3K27 acetylation and targeting SCAP N- glycosylation may be a new strategy for treating nonalcoholic steatohepatitis (NASH).

Several studies have confirmed that exosomes containing microRNAs (miRNAs) from the aseptic inflammatory microenvironment play an important role in bone remodeling. But the mechanism that induces changes in the osteogenic ability of periodontal ligament stem cells (PDLSCs) is still unclear. In the present study, the osteogenic function of periodontal ligament fibroblasts-derived exosomes induced by PGE 2 on PDLSCs was detected by real-time PCR, alizarin red assay and alkaline phosphatase staining. High-throughput miRNAs sequencing was used to reveal that miR-34c-5p in exosomes-PGE 2 was upregulated compared it in exosomes-normal. Real-time PCR and western blotting assay verified that overexpression of miR-34c-5p inhibited osteogenic differentiation, and reduced phosphorylation of ERK1/2. In addition, dual-luciferase reporter assay revealed that miR-34c-5p targeted special AT-rich sequence-binding protein 2 (SATB2). It was shown that exosomal miR-34c-5p inhibited osteogenic differentiation of PDLSCs via SATB2/ERK pathway., Competing Interests: Declaration of competing interest No competing interest exists., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: To determine the prevalence of non-carious cervical lesions (NCCLs) in maxillary premolars of different torques and simulated cervical stress profiles of the premolars under coincident loadings using finite element analysis (FEA)., Methods: The CBCT scans of 616 maxillary premolars from 154 subjects were retrospectively evaluated. The premolars were ascribed into low torque group (LTG) <-10.9°, medium torque group (MTG) -10.9° to -3.9°, and high torque group (HTG) >-3.9°, when the torque was referring to the occlusion plane. The prevalence of NCCLs in each group was evaluated. Then finite element models of a maxillary first premolar, its adjacent teeth and alveolar bone were established. The models were prepared with ANSYS software generating the premolars presenting different torques. The mastication scenario for the premolars in maximum intercuspation position was simulated., Results: The prevalence of NCCLs was 15.7% in LTG, 7.9% in MTG and 5.5% in HTG. The prevalence of LTG was significantly higher than that of MTG (P< 0.05) and HTG (P< 0.01). As for FEA, the stresses at the buccal necks of the premolars basically increased with decrease of the torque. The tensile stress peaks were in the cemento-enamel junction in most premolars of the LTG, while in the middle of the crowns in premolars of MTG and HTG., Clinical Significance: Low torque with excessive lingual inclination is a risk factor for NCCLs of maxillary premolars, and excessive tensile stress concentration in buccal necks during mastication may be responsible for that., Competing Interests: The authors declared no conflict of interest., (Copyright©American Journal of Dentistry.)