Anisotropic Deformation in the Compressions of Single Crystalline Copper Nanoparticles

Atomistic simulations are performed to probe the anisotropic deformation in the compressions of face-centred-cubic metallic nanoparticles. In the elastic regime, the compressive load-depth behaviors can be characterized by the classical Hertzian model or flat punch model, depending on the surface configuration beneath indenter. On the onset of plasticity, atomic-scale surface steps serve as the source of heterogeneous dislocation in nanoparticle, which is distinct from indenting bulk materials. Under [111] compression, the gliding of jogged dislocation takes over the dominant plastic deformation. The plasticity is governed by nucleation and exhaustion of extended dislocation ribbons in [110] compression. Twin boundary migration mainly sustain the plastic deformation under [112] compression. This study is helpful to extract the mechanical properties of metallic nanoparticles and understand their anisotropic deformation behaviors.Comment: 25 pages, 9 figure

E-Cadherin/β-Catenin Complex and the Epithelial Barrier

E-Cadherin/β-catenin complex plays an important role in maintaining epithelial integrity and disrupting this complex affect not only the adhesive repertoire of a cell, but also the Wnt-signaling pathway. Aberrant expression of the complex is associated with a wide variety of human malignancies and disorders of fibrosis resulting from epithelial-mesenchymal transition. These associations provide insights into the complexity that is likely responsible for the fibrosis/tumor suppressive action of E-cadherin/β-catenin

Increased Functional Brain Network Efficiency During Audiovisual Temporal Asynchrony Integration Task in Aging

Audiovisual integration significantly changes over the lifespan, but age-related functional connectivity in audiovisual temporal asynchrony integration tasks remains underexplored. In the present study, electroencephalograms (EEGs) of 27 young adults (22–25 years) and 25 old adults (61–76 years) were recorded during an audiovisual temporal asynchrony integration task with seven conditions [auditory (A), visual (V), AV, A50V, A100V, V50A and V100A]. We calculated the phase lag index (PLI)-weighted connectivity networks modulated by the audiovisual tasks and found that the PLI connections showed obvious dynamic changes after stimulus onset. In the theta (4–7 Hz) and alpha (8–13 Hz) bands, the AV and V50A conditions induced stronger functional connections and higher global and local efficiencies, reflecting a stronger audiovisual integration effect, which was attributed to the auditory information arriving at the primary auditory cortex earlier than the visual information reaching the primary visual cortex. Importantly, the functional connectivity and network efficiencies of old adults revealed higher global and local efficiencies and higher degree in both the theta and alpha bands. These larger network efficiencies indicated that old adults might experience more difficulties in attention and cognitive control during the audiovisual integration task with temporal asynchrony than young adults. There were significant associations between network efficiencies and peak time of integration only in young adults. We propose that an audiovisual task with multiple conditions might arouse the appropriate attention in young adults but would lead to a ceiling effect in old adults. Our findings provide new insights into the network topography of old adults during audiovisual integration and highlight higher functional connectivity and network efficiencies due to greater cognitive demand

Exploring the Mechanism of Action of Resveratrol in the Treatment of Non-small Cell Lung Cancer Based on Network Pharmacology and Experimental Validation

Objective: To explore the potential therapeutic targets and mechanisms of resveratrol in the treatment of non-small cell lung cancer (NSCLC), a comprehensive study was conducted incorporating network pharmacology, molecular docking methods, and experimental validation. Methods: The targets of resveratrol were searched on Swiss Target Prediction database and Target net database. NSCLC targets were gathered from Genecards, OMIM, TTD databases. The intersection of drug targets and disease targets was obtained using Venny 2.1.0 platform. Next, Cytoscape 3.7.2 software was applied along with the String database to generate target protein interaction networks (PPI) and perform topological analysis. GO functional enrichment analysis and KEGG pathway enrichment analysis of intersecting targets were conducted using the Metascape database, resulting in gene maps of the intersecting targets. Molecular docking studies were performed for the top three ranked core targets and resveratrol using Autodock Vina software. Clinical case samples were obtained from The Cancer Genome Atlas (TCGA) database to analyze the expression of relevant targets in NSCLC patients (n=1017) and healthy controls (n=627). The effects of different concentrations (30 and 50 μmol/L) of resveratrol on the protein expression of SRC, EGFR and PI3K/AKT signaling pathway in human lung adenocarcinoma A549 cells were examined using Western Blot at the cellular level. Results: Total of 40 potential targets were screened out, followed by obtaining 8 key targets after topological analysis. These keys targets, including EGFR, SRC, and ESR1 were closely associated with NSCLC. The treatment of NSCLC with resveratrol primarily involved multiple signaling pathways, such as tumor proteoglycans, estrogen signaling and PI3K/AKT. Molecular docking results demonstrated that resveratrol had a good binding ability with the target protein. Clinical sample results revealed that the expression of EGFR, SRC, ESR1, HSP90AA1, and MMP9 was upregulated, while the expression of TNF, CDC42, and RELA was downregulated in NSCLC patients. Cellular experiments indicated that resveratrol could inhibit the protein expression of SRC, EGFR, p-PI3K, and p-AKT in human lung adenocarcinoma A549 cells in a dose-dependent manner. Conclusion: This study demonstrates that resveratrol involves multiple targets and signaling pathways in the treatment of NSCLC, and clarifies that resveratrol could exert its anti-cancer effects by inhibiting the PI3K/AKT signaling pathway

Microstructure and Wear Resistance of TiCp/Ti6Al4V Composite Coatings by Follow-Up Ultrasonic-Assisted Laser Additive Manufacturing

With the increasing demand for the high agility and fast response of high-level equipment in the aerospace and energy power fields, it is increasingly urgent to improve the performance of the high-temperature and wear resistance of the corresponding high-level components. Ceramic-reinforced titanium matrix composites have excellent high-temperature and wear resistance, but, in laser additive manufacturing, the primary ceramic phase is coarse, and the morphology of the ceramic phase is difficult to control, which limits their further development. In this investigation, a follow-up ultrasonic-assisted laser-additive-manufacturing method was proposed to prepare a 30 wt.% TiC/Ti6Al4V composite coating on a Ti6Al4V surface. Under the effects of ultrasonic cavitation and acoustic streaming, the content of the unmelted TiC was reduced, the dendritic primary TiC in the solidification process was broken and the distribution uniformity of the primary TiC was improved. The content of the unmelted TiC in the composite coating decreased significantly under ultrasonic action, and it was only 50.23% of that without ultrasonic action. At the same time, the average size of the dendritic primary TiC in the composite coating decreased from 61.59 μm to 27.04 μm, which was 56.10% smaller than that without ultrasonic action. The average microhardness of the composite coating reached the maximum of 656.70 HV0.2 under ultrasonic power, and it was 83.21% higher than that of the Ti6Al4V substrate, and 26.44% higher than that of the composite coating without ultrasonic power. Due to the ultrasonic-cavitation and acoustic-streaming effects, the content of the unmelted TiC obviously decreased, so that the average friction coefficient of the composite coating increased, and the wear mechanism changed from abrasive wear to adhesive wear

Lysozyme Aptamer-Functionalized Magnetic Nanoparticles for the Purification of Lysozyme from Chicken Egg White

Lysozyme is in high demand due to its many favorable characteristics such as being naturally occurring, non-toxic, and easy to digest and absorb. Recently, superparamagnetic nanoparticles with strong magnetic responsiveness have attracted significant interest for enzyme purification. The aptamer of the enzyme can be chemically synthesized rapidly at a large scale using simple and low-cost preparation methods. Therefore, Fe3O4 nanoparticles (Fe3O4 NPs) were prepared by chemical co-precipitation and were then functionalized with amino groups to produce NH2-Fe3O4 NPs. The specific reaction of aldehyde and amino groups was used to attach lysozyme aptamers with specific sequences to NH2-Fe3O4 NPs to produce Apt-NH2-Fe3O4 NPs. The synthesized materials were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hysteresis loop analysis, and thermogravimetric analysis (TGA). The optimal experimental conditions for adsorption of lysozyme were investigated. The effects of initial lysozyme concentration, adsorption time, pH, reaction temperature, and ionic strength were determined. The maximum adsorption capacity and relevant activity of Apt-NH2-Fe3O4 NPs was 460 mg·g−1 and 16,412 ± 55 U·mg−1 in an aqueous lysozyme solution. In addition, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis analysis, lysozyme could be separated from crude fresh egg white using Apt-NH2-Fe3O4 NPs with an amount up to 113 ± 4.2 mg·g−1 and an activity up to 16,370 ± 46 U·mg−1

Bacillus Calmette-Guerin alleviates airway inflammation and remodeling by preventing TGF-β1 induced epithelial–mesenchymal transition

Bacillus Calmette-Guerin (BCG) is a potent agent for the prevention of tuberculosis. Current studies have regarded BCG as an immunomodulator. However, there is little information on whether it can be used to inhibit airway inflammation and airway remodeling caused by asthma. Therefore, in this study, we investigate the role of epithelial–mesenchymal transition (EMT) in airway inflammation and airway remodeling as well as the possible therapeutic mechanism of BCG for the treatment of asthma. Wistar rats were sensitized and challenged by ovalbumin for 2 weeks or 8 weeks. BCG was subcutaneously administered daily before every ovalbumin challenge to determine its therapeutic effects. The 2 weeks model group showed extensive eosinophilia, chronic inflammatory responses, bronchial wall thickening, airway epithelium damage, increased levels of transforming growth factor β 1 (TGF-β1) in both bronchoalveolar lavage fluid and sera, decreased expression of epithelial marker E-cadherin, and increased expressions of mesenchymal markers α-smooth muscle actin (α-SMA) and Fibronectin (Fn). Except for inflammatory responses, all responses were more significant in the 8 weeks model group which displayed characteristics of airway remodeling including subepithelial fibrosis, smooth muscle hypertrophy, and goblet cell hyperplasia. When compared with the model groups, BCG administration inhibited airway inflammation and airway remodeling, decreased TGF-β1 levels, upregulated expression of E-cadherin, and downregulated expression of α-SMA and Fn. The present study suggests for the first time that increased secretion of TGF- β1 induced by asthmatic chronic inflammation may result in EMT, which is one of the most important mechanisms of airway inflammation and airway remodeling seen with asthma. BCG alleviates airway inflammation and airway remodeling by preventing TGF-β1 induced EMT, therefore BCG may be a new therapy for treating asthma