Electronic Synapses Enabled by an Epitaxial SrTiO3-δ / Hf0.5Zr0.5O2 Ferroelectric Field-Effect Memristor Integrated on Silicon

Synapses play a vital role in information processing, learning, and memory formation in the brain. By emulating the behavior of biological synapses, electronic synaptic devices hold the promise of enabling high-performance, energy-efficient, and scalable neuromorphic computing. Ferroelectric memristive devices integrate the characteristics of both ferroelectric and memristive materials and present a far-reaching potential as artificial synapses. Here, it is reported on a new ferroelectric device on silicon, a field-effect memristor, consisting of an epitaxial ultrathin ferroelectric Hf_0.5Zr_0.5O₂ film sandwiched between an epitaxial highly doped oxide semiconductor SrTiO_3-δ and a top metal. Upon a low voltage of less than 2 V, the field-effect modulation in the semiconductor enables to access multiple states. The device works in a large time domain ranging from milliseconds down to tens of nanoseconds. By gradually switching the polarization by identical pulses, the ferroelectric diode devices can dynamically adjust the synaptic strength to mimic short- and long-term memory plasticity. Ionic contributions due to redox processes in the oxide semiconductor beneficially influence the device operation and retention.     

A Self-Renewing Biomimetic Skeletal Muscle Construct Engineered using Induced Myogenic Progenitor Cells

Skeletal muscle represents a highly organized tissue that primarily regenerates by myogenic stem cells. Mimicking an in vitro skeletal muscle differentiation program that contains self-renewing muscle stem cells and aligned myotubes is considered challenging. This study presents the engineering of a biomimetic muscle construct that can self-regenerate and produce aligned myotubes using induced myogenic progenitor cells (iMPCs), a heterogeneous culture consisting of skeletal muscle stem, progenitor, and differentiated cells. Utilizing electrospinning, polycaprolactone (PCL) substrates are fabricated to facilitate iMPC-differentiation into aligned myotubes by controlling PCL fiber orientation. Newly-conceived constructs contain organized multinucleated myotubes alongside self-renewing stem cells, whose differentiation capacity is augmented by Matrigel supplementation. Furthermore, this work utilizes single-cell RNA-sequencing (scRNA-seq) to demonstrate that iMPC-derived constructs faithfully recapitulate a step-wise myogenic differentiation program. Notably, when subjected to a damaging myonecrotic agent, self-renewing stem cells rapidly differentiate into aligned myotubes within the constructs, akin to skeletal muscle repair in vivo. Finally, this study demonstrates that the iMPC derivation protocol can be adapted to engineer human myoblast-derived muscle constructs containing aligned myotubes, showcasing potential for translational applicability. Taken together, this work reports a novel in vitro system that mirrors myogenic regeneration and skeletal muscle alignment for basic research and regenerative medicine.     

Epitaxial Growth of 1D Te/2D MoSe2 Mixed-Dimensional Heterostructures for High-Efficient Self-Powered Photodetector

Mixed-dimensional heterostructures provide additional freedom to construct diverse functional electronic and optoelectronic devices, gaining significant interest. Herein, highly-aligned pseudo-1D tellurium is epitaxially grown on 2D monolayer transition metal dichalcogenides (TMDs), including MoSe₂, MoS₂, and WS₂. A one-pot chemical vapor deposition (CVD) technique eliminates the normally required transfer steps, thereby producing mixed-dimensional heterostructures with an ultraclean interface. The controllable epitaxial growth of Te/TMD heterostructures are verified by Raman, scanning probe microscopy (SPM), and transmission electron microscopy (TEM) observation. The photoluminescence results indicate that the emission from TMDs is quenched in the heterostructure, confirming the efficient transfer of photogenerated carriers from TMDs to Te. Additionally, the mixed-dimensional p-n Te/MoSe₂ heterojunction photodetector presents self-driven behavior with high responsivity (328 mA W⁻¹), external quantum efficiency (79%), and specific detectivity (8.2 × 10⁹ Jones). The modified facile synthesis strategy and proposed growth mechanism in this study shed light on synthesizing mixed-dimensional heterojunctions. This opens avenues for fabricating functional devices with reduced sizes and high densities, further enabling miniaturization and integration opportunities.     

Can a Large Number of Transplanted Mesenchymal Stem Cells Have an Optimal Therapeutic Effect on Improving Ovarian Function?

Mesenchymal stem cells (MSCs) are next-generation treatment in degenerative diseases. For the application of mesenchymal stem cell therapy to degenerative disease, transplantation conditions (e.g., optimized dose, delivery route and regenerating efficacy) should be considered. Recently, researchers have studied the mode of action of MSC in the treatment of ovarian degenerative disease. However, the evidence for the optimal number of cells for the developing stem cell therapeutics is insufficient. The objective of this study was to evaluate the efficacy in ovarian dysfunction, depends on cell dose. By intraovarian transplantation of low (1 × 10⁵) and high (5 × 10⁵) doses of placenta-derived mesenchymal stem cells (PD-MSCs) into thioacetamide (TAA)-injured rats, we compared the levels of apoptosis and oxidative stress that depend on different cell doses. Apoptosis and oxidative stress were significantly decreased in the transplanted (Tx) group compared to the non-transplanted (NTx) group in ovarian tissues from TAA-injured rats (* p < 0.05). In addition, we confirmed that follicular development was significantly increased in the Tx groups compared to the NTx group (* p < 0.05). However, there were no significant differences in the apoptosis, antioxidant or follicular development of injured ovarian tissues between the low and high doses PD-MSCs group. These findings provide new insights into the understanding and evidence obtained from clinical trials for stem cell therapy in reproductive systems.     

Distributed Virtual Inertia Based Control of Multiple Photovoltaic Systems in Autonomous Microgrid

The large inertia of a traditional power system slows down system's frequency response but also allows decent time for controlling the system. Since an autonomous renewable microgrid usually has much smaller inertia, the control system must be very fast and accurate to fight against the small inertia and uncertainties. To reduce the demanding requirements on control, this paper proposes to increase the inertia of photovoltaic (PV) system through inertia emulation. The inertia emulation is realized by controlling the charging/discharging of the direct current (DC)-link capacitor over a certain range and adjusting the PV generation when it is feasible and/or necessary. By well designing the inertia, the DC-link capacitor parameters and the control range, the negative impact of inertia emulation on energy efficiency can be reduced. The proposed algorithm can be integrated with distributed generation setting algorithms to improve dynamic performance and lower implementation requirements. Simulation studies demonstrate the effectiveness of the proposed solution.      

Fractality of tics as a quantitative assessment tool for Tourette syndrome

Tics manifest as brief, purposeless and unintentional movements or noises that, for many individuals, can be suppressed temporarily with effort. Previous work has hypothesized that the chaotic temporal nature of tics could possess an inherent fractality, that is, have neighbour-to-neighbour correlation at all levels of timescale. However, demonstrating this phenomenon has eluded researchers for more than two decades, primarily because of the challenges associated with estimating the scale-invariant, power law exponent—called the fractal dimension D_f—from fractional Brownian noise. Here, we confirm this hypothesis and establish the fractality of tics by examining two tic time series datasets collected 6–12 months apart in children with tics, using random walk models and directional statistics. We find that D_f is correlated with tic severity as measured by the YGTTS total tic score, and that D_f is a sensitive parameter in examining the effect of several tic suppression conditions on the tic time series. Our findings pave the way for using the fractal nature of tics as a robust quantitative tool for estimating tic severity and treatment effectiveness, as well as a possible marker for differentiating typical from functional tics.     

Switchable diurnal radiative cooling by doped VO2

This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to...     

A Reaction Between High Mn–High Al Steel and CaO-SiO2-Type Molten Mold Flux: Reduction of Additive Oxide Components in Mold Flux by Al in Steel

Metallurgical and Materials Transactions B - The interfacial reaction between high-Mn–high-Al steel and CaO-SiO2-type mold flux was investigated, with particular emphasis on the reduction of...     

Therapeutic Potential of Human Fetal Mesenchymal Stem Cells in Musculoskeletal Disorders: A Narrative Review

Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic approach for diverse diseases and injuries. The biological and clinical advantages of human fetal MSCs (hfMSCs) have recently been reported. In terms of promising therapeutic approaches for diverse diseases and injuries, hfMSCs have gained prominence as healing tools for clinical therapies. Therefore, this review assesses not the only biological advantages of hfMSCs for healing human diseases and regeneration, but also the research evidence for the engraftment and immunomodulation of hfMSCs based on their sources and biological components. Of particular clinical relevance, the present review also suggests the potential therapeutic feasibilities of hfMSCs for musculoskeletal disorders, including osteoporosis, osteoarthritis, and osteogenesis imperfecta.