In recent years, due to the rapid development of science and technology in China, technology has continuously advanced the process of informatization in education. Among them, the emergence of ...micro-lectures has made learning more convenient and efficient. In Chinese compulsory education system, art education has always been hindered by the drawbacks of exam-oriented education, and the neglect of art classes is often observed in classrooms. Teachers always consider that art classes is less important than the major courses and lose sight of it. However, with the advent of the internet information era, micro-lectures have proposed new solutions and motivation for the difficulties and challenges faced by art education in China. Micro-lectures, due to their various advantages and characteristics, are a teaching method with great potential development in art education. This article mainly explores the capacity enhancement of primary and middle school students through micro-course teaching, and it has strong practical and application significance.
PIEZO2 is a mechanosensitive cation channel that has a key role in sensing touch, tactile pain, breathing and blood pressure. Here we describe the cryo-electron microscopy structure of mouse PIEZO2, ...which is a three-bladed, propeller-like trimer that comprises 114 transmembrane helices (38 per protomer). Transmembrane helices 1-36 (TM1-36) are folded into nine tandem units of four transmembrane helices each to form the unusual non-planar blades. The three blades are collectively curved into a nano-dome of 28-nm diameter and 10-nm depth, with an extracellular cap-like structure embedded in the centre and a 9-nm-long intracellular beam connecting to the central pore. TM38 and the C-terminal domain are surrounded by the anchor domain and TM37, and enclose the central pore with both transmembrane and cytoplasmic constriction sites. Structural comparison between PIEZO2 and its homologue PIEZO1 reveals that the transmembrane constriction site might act as a transmembrane gate that is controlled by the cap domain. Together, our studies provide insights into the structure and mechanogating mechanism of Piezo channels.
Current aqueous Zn batteries (ZBs) seriously suffer from dendrite issues caused by rough electrode surfaces. Despite significant efforts in prolonging lifespan of these batteries, little effort has ...been devoted to dendrite elimination in commercial‐grade cathode loading mass. Instead, demonstrations have only been done at the laboratory level (≤2 mg cm−2). Additionally, new dilemmas regarding change of the proton‐storage behavior and interface pulverization have emerged in turn. Herein, hydrogen‐substituted graphdiyne (HsGDY), with sub‐ångström level ion tunnels and robust chemical stability, is designed as an artificial interface layer to address these issues. This strategy prolongs the symmetric cell lifespan to >2400 h (100 days), which is 37 times larger than without protection (63 h). The simulation of dual fields reveals that HsGDY can redistribute the Zn2+ concentration field by spatially forcing Zn2+ to deviate from the irregular electric field. During practical use, the as‐assembled full batteries deliver a long lifespan 50 000 cycles and remain stable even at a commercial‐grade cathode loading mass of up to 22.95 mg cm−2. This HsGDY‐protection methodology represents great progress in Zn dendrite protection and demonstrates enormous potential in metal batteries.
Aqueous Zn‐based batteries suffering from the dendrite issue show a short lifespan, especially at commercial‐grade cathode loading mass. Hydrogen‐substituted graphdiyne with ion tunnels is employed to eliminate dendrites, based on ion redistribution, achieving a long lifespan of 10 000 cycles at a cathode loading mass of 22.95 mg cm−2. This work sheds light on tackling the dendrite issue encountered by metal batteries.
Obstructive sleep apnea (OSA) is a common respiratory disorder characterized by partial obstruction of upper respiratory tract and repetitive cessation of breathing during sleep. The etiology behind ...OSA is associated with the occurrence of intermittent hypoxemia, recurrent arousals and intrathoracic pressure swings. These contributing factors may turn on various signaling mechanisms including elevated sympathetic tone, oxidative stress, inflammation, endothelial dysfunction, cardiovascular variability, abnormal coagulation and metabolic defect (
., insulin resistance, leptin resistance and altered hepatic metabolism). Given its close tie with major cardiovascular risk factors, OSA is commonly linked to the pathogenesis of a wide array of cardiovascular diseases (CVDs) including hypertension, heart failure, arrhythmias, coronary artery disease, stroke, cerebrovascular disease and pulmonary hypertension (PH). The current standard treatment for OSA using adequate nasal continuous positive airway pressure (CPAP) confers a significant reduction in cardiovascular morbidity. Nonetheless, despite the availability of effective therapy, patients with CVDs are still deemed highly vulnerable to OSA and related adverse clinical outcomes. A better understanding of the etiology of OSA along with early diagnosis should be essential for this undertreated disorder in the clinical setting.
The treatment of tenacious diabetic wounds still remains an enormous challenge in clinics, originated from the complicated pathological microenvironment of wound sites. Therefore, it's urgently ...required to develop one type of innovative dressing patch with appropriate microstructure and multifunctions to regulate the pathological microenvironment and promote the regeneration of diabetic wounds. In this study, novel gelatin (Gel)/poly (L-lactic acid) (PLLA) nanofibrous yarns loading with or without Salvia miltiorrhiza Bunge-Radix Puerariae herbal compound (SRHC) are fabricated by using our modified electrospinning strategy, which are further interlaced into nanofibrous woven fabrics respectively, serving as biofunctional dressing patches for potential diabetic wound treatment application. The actual photographs and SEM images confirm that all the different nanofibrous textiles with or without SRHC exhibit a uniform interwoven structure of warp and weft, and the internal nanofibers present bead-free morphology and uniaxially oriented structure along the longitudinal axis of nanofibrous yarns. Moreover, all the different nanofibrous woven fabrics are demonstrated to possess strong mechanical properties and great surface wettability. The in vitro cell characterization shows that the addition of SRHC can significantly promote the attachment and proliferation of human dermal fibroblasts (HDFs), and also dramatically inhibit the secretion levels of proinflammatory factors of M1 macrophages. The in vivo diabetic mouse full-thickness skin model experiments reveal that the as-developed SRHC-loaded Gel/PLLA nanofibrous textile shows the best performances referring to shorten wound healing time (100 % wound closure after 18 days of treatment) and high-quality regeneration (i.e., enhance collagen deposition, improve re-epithelialization and neovascularization, and increase hair follicles), which assuredly finds great interests serving as an innovative dressing patch for the treatment of hard-to-heal diabetic wounds.
The endoplasmic reticulum (ER) and mitochondria are interconnected intracellular organelles with vital roles in the regulation of cell signaling and function. While the ER participates in a number of ...biological processes including lipid biosynthesis, Ca
storage and protein folding and processing, mitochondria are highly dynamic organelles governing ATP synthesis, free radical production, innate immunity and apoptosis. Interplay between the ER and mitochondria plays a crucial role in regulating energy metabolism and cell fate control under stress. The mitochondria-associated membranes (MAMs) denote physical contact sites between ER and mitochondria that mediate bidirectional communications between the two organelles. Although Ca
transport from ER to mitochondria is vital for mitochondrial homeostasis and energy metabolism, unrestrained Ca
transfer may result in mitochondrial Ca
overload, mitochondrial damage and cell death. Here we summarize the roles of MAMs in cell physiology and its impact in pathological conditions with a focus on cardiovascular disease. The possibility of manipulating ER-mitochondria contacts as potential therapeutic approaches is also discussed.
This paper presents a detection method of remotely identifying a potential active shooter with a concealed rifle/shotgun based on radar micro-Doppler and range-Doppler signature analysis. By studying ...and comparing the micro-Doppler and range-Doppler information of human subjects carrying a concealed rifle versus other similar activities, special features are extracted and applied for detecting people with suspicious behaviors. An artificial neural network is adopted in this work to complete the activity classification, and the classification result shows a 99.21% accuracy of differentiating human subjects carrying a concealed rifle from other similar activities. Due to the properties of radar sensor, the proposed method does not involve sensitive information such as visual images, and thus can better protect the privacy while being able to see-through the clothing for reliable detection.
The unique topological features of Piezo proteins underlie the lever-like cellular mechanotransduction mechanism. This knowledge inspires us to seek topological/geometric control of ...mechanochromophores with unprecedentedly amplified, synergistic changes in polymers to serve as ideal stress probes. Here, by judicious placement of two spirolactam rings into aminobenzopyranoxanthene, a series of stereo- and regio-isomeric rhodamine-like mechanophores are developed. With two labile bonds closely coupled into one rigidified scaffold, these π-fused bis-mechanophores enable mechanochromic polymers, featuring cooperative bond scission, low rupture force (lower than rhodamine), and geometry-controlled ring-opening reactivity. Sonication, single-molecule force spectroscopy experiments, and density functional theory calculations provide insight into the force–color relationship and rationalize how the difference in reactivity of the four isomeric mechanophores is affected by their molecular geometry and thermodynamic equilibrium. Our strategy based on the aromatic fusion of bis-mechanophore promises a modular approach to isomeric mechanophores for cooperative bond scission. Also, important insights into internal and external factors governing tandem mechanochemical reactions are gained.
This paper presents a Doppler radar vital sign detection system with random body movement cancellation (RBMC) technique based on adaptive phase compensation. An ordinary camera was integrated with ...the system to measure the subject's random body movement (RBM) that is fed back as phase information to the radar system for RBMC. The linearity of the radar system, which is strictly related to the circuit saturation problem in noncontact vital sign detection, has been thoroughly analyzed and discussed. It shows that larger body movement does not necessarily mean larger radar baseband output. High gain configuration at baseband is required for acceptable SNR in noncontact vital sign detection. The phase compensation at radar RF front-end helps to relieve the high-gain baseband from potential saturation in the presence of large body movement. A simple video processing algorithm was presented to extract the RBM without using any marker. Both theoretical analysis and simulation have been carried out to validate the linearity analysis and the proposed RBMC technique. Two experiments were carried out in the lab environment. One is the phase compensation at RF front end to extract a phantom motion in the presence of another large shaker motion, and the other one is to measure the subject person breathing normally but randomly moving his body back and forth. The experimental results show that the proposed radar system is effective to relieve the linearity burden of the baseband circuit and help compensate the RBM.
This letter investigates a downlink power control strategy for visible light communication (VLC) systems with non-orthogonal multiple access. Our goal is to maximize sum throughput of the multiuser ...VLC systems subject to both user fairness and unique intensity constraints for optical modulations. Though the original problem is nonconvex, we first transform it into an equivalent convex one by introducing auxiliary variables and applying variable transformation. Then, we present an optimal power control algorithm with low complexity. Numerical results show large rate gains compared to the conventional OFDM scheme.
PDF
