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Objective: The aim of this study was to investigate the relationship between radiographic severity and BMI, pain, and physical function in elderly women with knee osteoarthritis (OA). Methods: A total of 80 elderly women with knee OA were enrolled in this study. Their age, course of disease and body mass index (BMI) were recorded. Radiographic severity was assessed with the Kellgren-Lawrence (K/L) scale, and pain, stiffness, and physical function were assessed with Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scales, objective assessment of patients' functional performance using the Time Up and Go (TUG) test. Spearman correlation analysis was used to assess the relationship between radiographic K/L scores and BMI, pain, and physical function. Logistic regression analysis was used to determine the important factors contributing to knee OA severity. Result：The mean age of the patients was 64.7 ± 6.77 years, and the mean course of disease was 5.02±2.12 years. There was no significant correlation between radiographic severity K/L and normal BMI (p=0.087), but there was a moderate correlation between radiographic severity K/L and high BMI (p=0.02, r=0.457). It was positively correlated with WOMAC pain, stiffness and physical function (p=0.001, r=0.447; p=0.004, r=0.316; p=0.025, r=0.250). In addition, K/L grading was positively correlated with TUG (p= 0.001, r=0.395). On the other hand, BMI, pain, and stiffness may be the important influencing factors of the severity of knee OA, while age, course of disease, and physical function have little influence on the severity of knee OA. Conclusion: The radiographic severity of knee OA was correlated with high BMI, pain, and physical function, and high BMI, knee pain and stiffness were important factors for the severity of knee OA.

To elucidate whether cranial electrotherapy stimulation (CES) improves depression-like behavior of post-stroke depression (PSD) via regulation of glutathione peroxidase 4 (GPX4)-mediated brain-derived neurotrophic factor (BDNF) expression. Middle cerebral artery occlusion (MCAO) and chronic unpredictable mild stress (CUMS) were used to develop a rat PSD model. CES was applied, and RAS-selective lethal 3 (RSL3) was injected into the hippocampus to inhibit GPX4 in PSD rats. The depression behavior was detected by sucrose preference and forced swimming tests. The structure and morphology of the hippocampus were observed and analyzed by histopathological hematoxylin-eosin (HE) staining. The mRNA and protein expressions of GPX4 and BDNF in the hippocampus were detected by qRT-PCR, western blot and immunohistochemical analysis.The degeneration and necrosis of hippocampal neurons, the depression-like behavior were severer and the expression of BDNF in the hippocampus were decreased in PSD rats than those in MCAO and control groups. CES promoted the hippocampal neuron repair, alleviated the depression-like behavior and increased the expression of BDNF in PSD rats. The inhibition of GPX4 by RSL3 exacerbated the depression-like behavior and decreased the expression of BDNF in PSD rats. In addition, we found that RSL3 disrupted the positive effects of CES on the PSD rats. Conclusion: CES improves depression-like behavior of PSD rats through upregulation of GPX4-mediated BDNF expression in the hippocampus.

Background: The present study explored whether low-intensity pulsed ultrasound (LIPUS) enhances the therapeutic efficacy of mesenchymal stem cells (MSCs) in osteoarthritis (OA) cartilage repair by regulating autophagy-mediated exosome release. Methods: MSCs were isolated from the rat bone marrow and treated with rapamycin, 3-methyladenine, or LIPUS. The mechanism of the LIPUS-stimulated exosome release by MSCs was analyzed by inhibiting autophagy. Additionally, the MSCs were co-cultured with OA chondrocytes and stimulated by LIPUS, with or without exosome release inhibitor intervention. The exosome release was detected through transmission electron microscopy (TEM), nanoparticle tracking analysis, and biomarker expression analysis. Autophagy was analyzed through TEM, autophagy-related gene expression analysis, and immunofluorescence analysis in vitro. Furthermore, a rat knee OA model was constructed and treated with MSCs, GW4869, and LIPUS. The cartilage repair was assessed through histopathological analysis and extracellular matrix protein expression analysis. Results: The in vitro results indicated that LIPUS promoted MSC exosome release by activating autophagy. The in vivo results demonstrated that LIPUS significantly enhanced the positive effects of MSCs on OA cartilage. These effects were significantly blocked by GW4869, an inhibitor of exosome release. Conclusion: LIPUS can enhance the therapeutic efficacy of MSCs in OA cartilage repair, and the underlying mechanism is related to the increase in autophagy-mediated exosome release

Objective: To evaluate ultrasound-targeted simvastatin-loaded microbubble destruction (UTMDSV) attenuation of osteoarthritis (OA) progression in rabbits through modulation of the peroxisome proliferator-activated receptor (PPARγ)-mediated cholesterol efflux pathway.Methods: In vitro, chondrocytes were treated with ultrasound (US), US-targeted microbubble destruction (UTMD), simvastatin (SV) and UTMDsv on alternate days for 4 weeks. Chondrocytes were also treated with PPARγ inhibitor, PPARγ inhibitor+UTMDsv and UTMDsv. The cholesterol efflux rate and triglyceride were measured respectively by assay kit and oil red O staining. In vivo, the OA rabbits were treated with a single intra-articular injection of UTMD, SV and UTMDSV every 7 days for 4 weeks. Cartilage histopathology was assessed by safranin-O staining and the Mankin score. Total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) in rabbit knee synovial fluid were detected by enzyme-marker assay. Aggrecan, collagen II and PPARγ expression levels were analyzed western blotting (WB).Results: OA models exhibited primarily by a loss of aggrecan and collagen II, changes to subchondral bone architecture and cartilage degradation. In vitro, UTMDSV significantly increased the cholesterol efflux rate and aggrecan, collagen II and PPARγ levels in OA chondrocytes; these effects were blocked by the PPARγ inhibitor. In vivo, UTMDSV significantly increased aggrecan, collagen II, PPARγ and HDL-C levels, while TC levels and Mankin scores were decreased compared with the UTMD, SV, OA and control groups (95% CI: 0.069 to 6.671).Conclusion: UTMDSV promotes the expression of aggrecan and collagen II and relieve cartilage degradation by modulating the PPARγ-mediated cholesterol efflux pathway in rabbits.

Objective The present study explored whether low-intensity pulsed ultrasound (LIPUS) enhances the therapeutic efficacy of mesenchymal stem cells (MSCs) in osteoarthritis (OA) cartilage repair by regulating autophagy-mediated exosome release. Design MSCs were isolated from the rat bone marrow and treated with rapamycin, 3-methyladenine, or LIPUS. The mechanism of the LIPUS-stimulated exosome release by MSCs was analyzed by inhibiting autophagy. In addition, the MSCs were co-cultured with OA chondrocytes and stimulated by LIPUS, with or without exosome release inhibitor intervention. The exosome release was detected through transmission electron microscopy (TEM), nanoparticle tracking analysis, and biomarker expression analysis. Autophagy was analyzed through TEM, autophagy-related gene expression analysis, and immunofluorescence analysis in vitro. Furthermore, a rat knee OA model was constructed and treated with MSCs, GW4869, and LIPUS. The cartilage repair was assessed through histopathological analysis and extracellular matrix protein expression analysis. Results The in vitro results indicated that LIPUS promoted MSC exosome release by activating autophagy. The in vivo results demonstrated that LIPUS significantly enhanced the positive effects of MSCs on OA cartilage. These effects were significantly blocked by GW4869, an inhibitor of exosome release. Conclusions LIPUS can enhance the therapeutic efficacy of MSCs in OA cartilage repair, and the underlying mechanism is related to the increase in autophagy-mediated exosome release.

Benzotriazole (BTA) and tolyltriazole (TTA) were used to passivate pure copper and chromium bronze alloys for environmental protection. Using the chemical immersion treatment, a dense film of chromium-free passivation layer was formed on surfaces of both the pure copper and chromium bronze alloys. Microstructure, crystalline phases and chemical bonds of the passivation layers were systematically characterized, and the passivation mechanisms were studied. The passivation layer was mainly consisted of CuO, Cu2O, polymers of Cu-BTA-TTA and Cu(I)BTA-TTA. The formation mechanism of the chromium-free passivation layer was identified as combined oxidation and adsorption, and the main passivation processes included oxidation and dissolution of the matrix, adsorption of BTA and its derivatives, self-stabilization process of the adsorbed film, and filling of passivation film’s voids by oxide particles.

The aim of this work was to join Molybdenum (Mo) and a graphite to obtain laminated structure using a high-temperature and hot press welding method with a Ti-Zr foil as the binder in a vacuum condition. The microstructure and composition changes of the interface were characterized by scanning electron microscopy and X-ray diffraction, respectively. The properties of the interface were studied using shear tests and hardness measurements. The optimal processing conditions for Mo and graphite joints involved a pressure of 0.5–1 MPa, holding time of 10–30 s, and brazing time of 5 min with a melting current of less than 150 A under a 1.3 × 10 −3 Pa vacuum condition. A transition zone with a width of approximately 0.3 mm and an average micro-hardness reaching 565 HV was formed, which is much higher than that of graphite and Mo. The main reason is the formation of different carbide and solid solutions such as MoC, Mo 9 Ti 4 , and Ti 2 C 0.06 . The shear bond strength of the graphite and molybdenum connection is 15.2 MPa, which is higher than that of graphite. The connection mechanism of Mo and graphite was the interlayer reacting with the Mo or graphite substrate at a high temperature to form compounds and solid solutions, respectively, covering the surface of the substrate. Therefore, an effective connection of Mo and graphite was successfully achieved. A model of the Mo and graphite connection structure was introduced.

W-Cu alloy sheets were fabricated in this study by multiple high temperature and high pressure (multi-HTHP) deformation technique. Crystalline structures and phase composition of W-Cu alloy sheets were investigated by transmission electron microscopy and X-ray diffraction, respectively. Results showed that W-Cu alloys possessed only W and Cu phases without other intermediate phases or solid solution of W and Cu. But shape, size and distribution of the two phases were changed after multi-HTHP deformation. Phase composition was also found without any changes after the multi-HTHP deformation treatments. Additionally, W-Cu alloy sheets with a relative density of 99.97% can be successfully obtained by multi-HTHP techniques. Cu phases are closely surrounded by W particles to form a net-work structure and W particles were also refined during the process of multi-HTHP, as a result, W-Cu alloy sheets with a higher properties in electrical conductivity (Ec) and micro-hardness reach 46.8% IACS and 450 HV, respectively, was obtained.

CNTs/Cu composite powders were prepared by an electroless plating and planetary ball milling process. The structure of composite powders was investigated. Results showed that Cu particles are homogeneously deposited on CNTs surface, and CNTs are deeply embedded into Cu matrix after milling, which play an important role in the dispersion and the wettability of CNTs within matrix and subsequently in the mechanical properties of composites. And the bulk CNTs/Cu was fabricated by vacuum sintering, re-pressing and re-sintering, and cold drawing process. It revealed that comparing pure Cu and composite without electroless plating, the tensile strength of composite with electroless plating increases obviously, up to 207 MPa. SEM images revealed that agglomeration is the main reason of deteriorating mechanical properties of composites. Finally, higher strength composites were successfully obtained by cold drawing. Results demonstrated that it can significantly improve the mechanical properties of the composites. Also, the tensile strength and the yield strength are up to 311 MPa and 185 MPa, respectively. SEM images clearly revealed that it is the dispersion and directional distribution of CNTs in matrix that further improve the strength of composites in drawing orientation. The load transfer theory was also employed to testify the results, effectively.

In this work, graphene was chosen to add into W70Cu30 alloys to develop properties of arc erosion. The effect of graphene addition on arc ablation behavior of W70Cu30 contacts was investigated by the measurement of weight-loss and the vacuum electrical breakdown tests. Also, the surface morphology of W70Cu30 contacts was analyzed by using scanning electron microscopy (SEM) after arc breakdown the first and 100 times. The results reveal that addition of graphene can enhance the breakdown strength a lot, which reach up to ∼45.5%, with a maximum value of 8.5 × 106 V/m. Compared with W70Cu30 alloys without any additives, the surface morphology of W70Cu30 alloys with graphene addition have a slight splash of molten copper and a small, flat cathode craters, thus, avoiding the concentration erosion on the surface of contacts. The main ablation mechanisms of W70Cu30 alloys with graphene addition was considered to be electron transition, energy consumption and difference work function of W, Cu, graphene, respectively.