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Background Excessive levels of oxidative stress and long-term inflammatory state seriously affect wound healing in diabetic patients. At present, there are biological agents, traditional Chinese medicines, stem cell therapy etc. used in treating diabetic cutaneous ulcer (DCU) . Due to lack of sufficient evidence of safety and effectiveness, these methods are not widely applied in clinical treatment. Thus new drugs need to be discovered urgently. Hyaluronic acid oligosaccharide (o-HA) is a potential drug for the treatment of DCU because of its antioxidant and anti-inflammatory properties. Objective To observe the effect of o-HA on DCU wound healing and explore its influence on oxidative stress Nrf2 signaling pathway. Methods This experiment was conducted from April to December, 2021. Ninety SPF male mice of six-week-old from Kunming were selected. Ten of them were reserved as the normal control group (NC group) and the rest were injected with streptozotocin (STZ) by abdomen to induce diabetes mouse model. Sixty diabetic mice modeled successfully were divided into 6 groups according to random number table with ten in each group, namely the diabetic model group (DM group) , the recombinant human epidermal growth factor positive control group (rhEGF group) , the blank matrix negative group (matrix group) , low-dose o-HA treatment group (0.5% o-HA group) , medium-dose o-HA treatment group (1% o-HA group) and high-dose o-HA treatment group (2% o-HA group) . The DCU model was established in all mice by way of the full-thickness skin excision ring splint. The wounds in NC and DM group were not treated. For the other groups, the corresponding medicines were evenly applied to and around the wounds after daily disinfection. The mice in rhEGF group were administered once a day while the mice in the 0.5%, 1% and 2% o-HA group were medicated twice a day for consecutive 14 days. The wound healing condition of DCU mice was recorded after being treated on the first, the 7th and the 14th day. The morphological changes of granulation tissue, collagen fiber formation and angiogenesis in mice wounds were observed by HE staining, Masson staining and CD34 immunohistochemical staining. The serum SOD and MDA levels of mice were examined by the kits. The Nrf2, HO-1 and NQO1 protein expression in wound tissue of mice were detected by Western-blotting after the administration of 14 days. Results On the seventh day of administration, the wound healing rate of rhEGF group and 1% o-HA group was higher than that of DM group and the wound healing rate of 0.5% o-HA group and 2% o-HA group was lower than that of NC group and higher than that of DM group. On the 14th day of administration, the wound healing rate of rhEGF group, 0.5% o-HA group, 1% o-HA group and 2% o-HA group was higher than that of DM group (P

The influence of grain size on the corrosion behavior of pure aluminum and the defect density and diffusion coefficient of surface passive films were investigated using electron backscatter diffraction (EBSD) and electrochemical testing techniques, based on the point defect model (PDM). Samples with three different grain sizes (23 ± 11, 134 ± 52, and 462 ± 203 μm) were obtained by annealing at different temperatures and times. The polarization curves and electrochemical impedance spectroscopy results for the pure aluminum in the 3.5% NaCl solution showed that with decreasing grain size, the corrosion current (icorr) decreased monotonously, giving rise to a noble corrosion potential and a large polarization resistance. The Motte–Schottky results showed that the passive films that formed on pure aluminum with fine grains of 23 ± 11 μm had a low density (3.82 × 1020 cm−3) of point defects, such as oxygen vacancies and/or metal interstitials, and a small diffusion coefficient (1.94 × 10−17 cm2/s). The influence of grain size on corrosion resistance was discussed. This work demonstrated that grain refinement could be an effective approach to achieving high corrosion resistance of passive metals. [ABSTRACT FROM AUTHOR]

Objectives This study aimed to investigate the high-resolution CT (HRCT) characteristics of anti-melanoma differentiation-associated gene 5 (MDA5) antibody positive dermatomyositis-associated interstitial lung disease (anti-MDA5 DM-ILD), and to clarify the underlying mechanisms of the clinical phenomenon. Methods Clinical data and HRCT patterns were compared between anti-MDA5 DM-ILD (n  = 32) and antisynthetase syndrome-associated ILD (ASS-ILD) (n  = 29). RNA sequencing of whole-blood samples from the two groups, and in vitro experiments using human embryonic lung fibroblasts (HELFs) were conducted to explore the potential mechanisms of the clinical findings. Results The anti-MDA5 DM-ILD subset had a significantly higher incidence of rapidly progressive ILD (RPILD) than ASS-ILD (65.6% vs 37.9%; P  = 0.031). The relative percentage of the lung fibrosis HRCT pattern was significantly lower in the anti-MDA5 DM-ILD group, especially the RPILD subgroup (P  = 0.013 and 0.003, respectively). RNA sequencing detected the upregulated genes including interferon-induced helicase C domain 1 (encoding MDA5), and a trend towards downregulated expression of TGF-β signalling components in anti-MDA5 DM-ILD. In vitro culture of HELFs revealed that upregulated expression of MDA5 in HELFs was correlated with the downregulated expression of alpha smooth muscle actin, connective tissue growth factor, collagen I and collagen III by suppressing the TGF-β signalling pathway. Conclusions Anti-MDA5 DM-ILD patients have significantly less lung fibrosis and elevated MDA5 expression. The upregulated expression of MDA5 has relations with the suppression of the pro-fibrotic function of fibroblasts via the TGF-β signalling pathway, which may partially explain the mechanism of the clinical phenomenon. [ABSTRACT FROM AUTHOR]