Uncertainty Quantification Visualization Tool to Simulate Porous Lithium-Ion Batteries

To maintain people’s fast-paced lifestyles, a more powerful and reliable rechargeable battery is critical. During the manufacturing process, electrode parameters such as cathode thickness, the porosity of the positive electrode and radius of negative active materials are subject to uncertainty. Such uncertainty may have a dramatic impact on the performance of the battery. To optimize its performance, it is critical to quantify uncertainty due to variation in electrode parameters and measure the response of the system through multiscale computer simulation. To achieve this goal, a porous lithium-ion battery uncertainty quantification and visualization tool has been created. This tool consists of three components: 1) a generator of uncertainty input; 2) an electrochemical system simulator; 3) a statistical analysis and visualization module. This project focuses on the first and the third components. First, the uncertainty input generator provides the option of selecting one of two statistical models for the input parameter distributions: Gaussian and lognormal. For Gaussian and lognormal distributions, sample points and weights are generated based on Gauss-Hermite quadrature formula. Each module provides a GUI, built using an open source, class-oriented environment, the Virtual Kinetics of Materials Lab [1]. Ensemble simulations are performed using the electrochemical system simulator that in turn uses the data distributions obtained from the uncertainty input generator. In the statistics analysis and visualization component, the simulation results are quantified graphically through error bar plots that visualize the impact of the uncertainties that were introduced into the system. The variation of power and energy densities as a function of current density of the battery electrode is presented, enabling the user to visualize the uncertainty propagation from the three electrode uncertainty inputs and its impact on the battery performance. [1] Alex Bartol; R. Edwin García; David R. Ely; Jon Guyer (2015), The Virtual Kinetics of Materials Laboratory, https://nanohub.org/resources/vkmllive. (DOI: 10.4231/D3B853J85)

Adjusting the Dose of Ag-Ion Implantation on TiN–Ag-Modified SLA-Ti Creates Different Micronanostructures: Implications on Bacteriostasis, Biocompatibility, and Osteogenesis in Dental Implants

The prevention of aseptic loosening and peri-implantitis is crucial for the success of dental implant surgery. In this study, different doses of Ag-implanted TiN/Ag nanomultilayers were prepared on the sandblasting with large grit and acid etching (SLA)-Ti surface using a multiarc ion-plating system and an ion-implantation system, respectively. The physical and chemical properties of the samples were assessed using various techniques, including scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, inductively coupled plasma atomic emission spectrometry, and water contact angle measurements. In addition, the applicability and biosafety of the SLA/1 × 1017-Ag and SLA/1 × 1018-Ag surfaces were determined via biocompatibility testing in vivo and in vitro. The results demonstrated that the physical and chemical properties of SLA/1 × 1017-Ag and SLA/1 × 1018-Ag surfaces were different to some extent. However, compared with SLA-Ti, silver-loaded TiN/Ag-modified SLA-Ti surfaces (SLA/1 × 1018-Ag) with enhanced bacteriostatis, osteogenesis, and biocompatibility have great potential for dental applications

Maintenance of Nucleolar Homeostasis by CBX4 Alleviates Senescence and Osteoarthritis

Summary: CBX4, a component of polycomb repressive complex 1 (PRC1), plays important roles in the maintenance of cell identity and organ development through gene silencing. However, whether CBX4 regulates human stem cell homeostasis remains unclear. Here, we demonstrate that CBX4 counteracts human mesenchymal stem cell (hMSC) aging via the maintenance of nucleolar homeostasis. CBX4 protein is downregulated in aged hMSCs, whereas CBX4 knockout in hMSCs results in destabilized nucleolar heterochromatin, enhanced ribosome biogenesis, increased protein translation, and accelerated cellular senescence. CBX4 maintains nucleolar homeostasis by recruiting nucleolar protein fibrillarin (FBL) and heterochromatin protein KRAB-associated protein 1 (KAP1) at nucleolar rDNA, limiting the excessive expression of rRNAs. Overexpression of CBX4 alleviates physiological hMSC aging and attenuates the development of osteoarthritis in mice. Altogether, our findings reveal a critical role of CBX4 in counteracting cellular senescence by maintaining nucleolar homeostasis, providing a potential therapeutic target for aging-associated disorders. : Ren et al. identify a geroprotective role for CBX4 in human mesenchymal stem cells (hMSCs) by maintaining nucleolar homeostasis. Overexpression of CBX4 alleviates hMSC aging and attenuates the development of osteoarthritis, highlighting a potential avenue for the use of CBX4 gene therapy vector in treating aging and aging-related disorders. Keywords: CBX4, stem cell, aging, nucleolus, rDNA, epigenetics, heterochromatin, osteoarthritis, CRISPR/Cas9, gene editin