Highly antibacterial rGO/Cu2O nanocomposite from a biomass precursor:Synthesis,performance,and mechanism

Reduced graphene oxide(rGO)has been widely used to fabricate electronics,sensors,photodetectors,and in other applications.However,the antibacterial performance of pristine rGO is relatively weak.The application of rGO in biomedical devices,smart food packaging,and water desalination membranes requires further improvement of rGO’s antibacterial abilities.Copper(I)oxide(Cu2O)is an effective antibacterial agent,which denatures protein and enhances the permeability of cell membranes.In this work,we report a simple method of synthesizing a highly antibacterial rGO/Cu2O nanocomposite from cellulose acetate,a derivative of abundant natural cellulose.The synthesized rGO/Cu2O nanocomposite was thoroughly characterized by Raman spectroscopy,X-ray powder diffraction(XRD),X-ray photoelectron spectroscopy(XPS),atomic force microscopy(AFM),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),and scanning transmission electron microscopy(STEM).Then,the antibacterial abilities of rGO/Cu2O nanocomposite were evaluated and a bactericidal mechanism was revealed from the molecular biology perspective.Results indicate that our synthesized rGO/Cu2O nanocomposite owns strong antibacterial activity,mainly stemming from the uniformly incorporated Cu2O nanocrystals with a lateral size of 5–40 nm.

Effects of Activating Blood Circulation to Resolve Blood Stasis and Glucosamine Capsules Therapy on the Expression of Matrix Metalloproteinase in Post-traumatic Knee Osteoarthritis

[Objectives] To observe the clinical effects of activating blood circulation to resolve blood stasis and glucosamine hydrochloride capsules therapy on post-traumatic knee osteoarthritis treatment,to measure the expression of matrix metalloproteinase in post-traumatic knee osteoarthritis patients before and after treatment,and to explore its relevant molecular mechanisms. [Methods]A total of 60 patients with posttraumatic knee osteoarthritis in early stage in Affiliated Hospital of Shannxi University of Chinese Medicine from January 2015 to December2017 were selected and randomly divided into the control group( n = 30) and the observation group( n = 30). The control group was given oral administration of glucosamine hydrochloride capsules for 6 courses of the treatment. The observation group was using the activating blood circulation to resolve blood stasis therapy for 6 courses of treatment. The recovery of traumatic knee osteoarthritis and the symptom of traditional Chinese medicine( TCM) in 2 groups was compared before and after treatment. The symptoms and the quantitative assessment rating scale of knee osteoarthritis,the pain index of knee and the TCM symptom scores were recorded in both groups. And the synovial fluid and serum of patients were collected to detect the expression of matrix metalloproteinase. [Results]The symptoms and the quantitative assessment rating scale of knee osteoarthritis,the pain index of knee and TCM symptom scores of the 2 groups in the 1 st week,the 12 th week and the 24 th week after the treatment were significantly lower than those before the treatment,and the difference was statistically significant( P < 0. 05). Two therapeutic methods had certain therapeutic effects on the recovery from traumatic knee osteoarthritis,and could significantly improve the TCM syndrome. There were better therapeutic effects on oral decoction of traditional Chinese medicine than oral glycosaminoglycans hydrochloride capsules on treating traumatic knee osteogenesis( P < 0. 05). The expression level of MMP3 was decreased significantly in both groups( P <0. 001),while the expression level of MMP13 had no significant change in both groups( P >0. 05). The expression level of MMP1 was decreased significantly in the observation group( P < 0. 001),but there was no significant change in the control group after treatment( P >0. 05). [Conclusions]Two treatment methods have been effective in this clinical study. We found that the expression level of MMP3 was decreased significantly after treatment in 2 therapies,which can be clinically applied.

牡蛎肽通过NF-κB/iNOS信号通路改善肝纤维化

本文研究探讨牡蛎肽(OP)改善肝纤维化的机制可能是通过NF-κB/iNOS信号通路。将50只雄性SD大鼠采用随机数字表法随机分为5组:对照组、模型组、低剂量(0.5 g/kg) OP组、中剂量(1.0 g/kg) OP组、高剂量(2.0 g/kg) OP组,每组10只。皮下注射50%四氯化碳(CCl4)建立肝纤维化大鼠模型6周。结果发现,OP治疗组中,CCl4诱导的肝纤维化大鼠肝脏中Ⅰ型胶原、Ⅲ型胶原和TGF-β1表达水平均显著低于模型组(P<0.05)。OP可以下调大鼠的肝组织NF-κB和iNOS的表达,可能是通过介导NF-κB/iNOS信号通路改善大鼠肝纤维化。