The 3D organization of chromatin regulates many genome functions. Our understanding of 3D genome organization requires tools to directly visualize chromatin conformation in its native context. Here ...we report an imaging technology for visualizing chromatin organization across multiple scales in single cells with high genomic throughput. First we demonstrate multiplexed imaging of hundreds of genomic loci by sequential hybridization, which allows high-resolution conformation tracing of whole chromosomes. Next we report a multiplexed error-robust fluorescence in situ hybridization (MERFISH)-based method for genome-scale chromatin tracing and demonstrate simultaneous imaging of more than 1,000 genomic loci and nascent transcripts of more than 1,000 genes together with landmark nuclear structures. Using this technology, we characterize chromatin domains, compartments, and trans-chromosomal interactions and their relationship to transcription in single cells. We envision broad application of this high-throughput, multi-scale, and multi-modal imaging technology, which provides an integrated view of chromatin organization in its native structural and functional context.
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•Massively multiplexed FISH enables mapping chromatin structure at genome scale•Multimodal high-throughput imaging places chromatin structure in functional context•Trans-chromosome or long-range interactions occur preferentially among active chromatin•Transcription activity correlates with local enrichment of compartment A chromatin
Su et al. present a high-throughput, multi-modal imaging platform to assay the 3D organization of chromatin at genome scale in its functional context in thousands of cells. This platform enables integrated measurements of more than 1,000 genomic loci together with the transcription activity of more than 1,000 genes in the same cells with landmark nuclear structures, making it possible to directly link gene activity to chromosome folding and to answer interesting biological questions.
Photonic computing and neuromorphic computing could address the inherent limitations of traditional von Neumann architecture and gradually invalidate Moore's law. As photonics applications are ...capable of storing and processing data in an optical manner with unprecedented bandwidth and high speed, two‐terminal photonic memristors with a remote optical control of resistive switching behaviors at defined wavelengths ensure the benefit of on‐chip integration, low power consumption, multilevel data storage, and a large variation margin, suggesting promising advantages for both photonic and neuromorphic computing. Herein, the development of photonic memristors is reviewed, as well as their application in photonic computing and emulation on optogenetics‐modulated artificial synapses. Different photoactive materials acting as both photosensing and storage media are discussed in terms of their optical‐tunable memory behaviors and underlying resistive switching mechanism with consideration of photogating and photovoltaic effects. Moreover, light‐involved logic operations, system‐level integration, and light‐controlled artificial synaptic memristors along with improved learning tasks performance are presented. Furthermore, the challenges in the field are discussed, such as the lack of a comprehensive understanding of microscopic mechanisms under light illumination and a general constraint of inferior near‐infrared (NIR) sensitivity.
The development of photonic memristors and their application in photonic computing and emulation on optogenetics‐modulated artificial synapses are reviewed. Photoactive materials as photosensing and storage media are discussed, considering their optical‐tunable memory behavior and resistive switching mechanism including photogating and photovoltaic effect. Light‐involved logic operations, system level integration, and artificial synaptic memristors along with improved learning tasks performance are presented.
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a new type of coronavirus that causes the Coronavirus Disease 2019 (COVID-19), which has been the most challenging pandemic in this ...century. Considering its high mortality and rapid spread, an effective vaccine is urgently needed to control this pandemic. As a result, the academia, industry, and government sectors are working tightly together to develop and test a variety of vaccines at an unprecedented pace. In this review, we outline the essential coronavirus biological characteristics that are important for vaccine design. In addition, we summarize key takeaways from previous vaccination studies of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV), highlighting the pros and cons of each immunization strategy. Finally, based on these prior vaccination experiences, we discuss recent progress and potential challenges of COVID-19 vaccine development.
Neuromorphic computing systems that are capable of parallel information storage and processing with high area and energy efficiencies, offer important opportunities for future storage systems and ...in‐memory computing. Here, it is shown that a carbon dots/silk protein (CDs/silk) blend can be used as a light‐tunable charge trapping medium to fabricate an electro‐photoactive transistor synapse. The synaptic device can be optically operated in volatile or nonvolatile modes, ensuring concomitant short‐term and long‐term neuroplasticity. The synaptic‐like behaviors are attributed to the photogating effect induced by trapped photogenerated electrons in the hybrid CDs/silk film which is confirmed with atomic force microscopy based electrical techniques. In addition, system‐level pattern recognition capability of the synaptic device is evaluated by a single‐layer perceptron model. The remote optical operation of neuromorphic architecture provides promising building blocks to complete bioinspired photonic computing paradigms.
An optoelectronic synaptic transistor based on a hybrid light‐tunable charge trapping medium is demonstrated. Optical programming and electrical erasing memory characteristics, along with volatile and nonvolatile memory are features of the synaptic device, enabling the mimicking of a range of neuroplasticity behaviors, including short‐term plasticity and long‐term potentiation.
2D metal oxides have aroused increasing attention in the field of electronics and optoelectronics due to their intriguing physical properties. In this review, an overview of recent advances on ...synthesis of 2D metal oxides and their electronic applications is presented. First, the tunable physical properties of 2D metal oxides that relate to the structure (various oxidation‐state forms, polymorphism, etc.), crystallinity and defects (anisotropy, point defects, and grain boundary), and thickness (quantum confinement effect, interfacial effect, etc.) are discussed. Then, advanced synthesis methods for 2D metal oxides besides mechanical exfoliation are introduced and classified into solution process, vapor‐phase deposition, and native oxidation on a metal source. Later, the various roles of 2D metal oxides in widespread applications, i.e., transistors, inverters, photodetectors, piezotronics, memristors, and potential applications (solar cell, spintronics, and superconducting devices) are discussed. Finally, an outlook of existing challenges and future opportunities in 2D metal oxides is proposed.
Emerging 2D metal oxides exhibit intriguing electronic and optical properties, which have great potential in emerging functional devices. Diverse structures and various synthesis methods open a new field of vision for device‐fabrication‐based 2D metal oxides. Their unique properties can bring new vigor and vitality into 2D material family.
Employee turnover continues to represent one of the most significant challenges faced by the U.S. restaurant industry, and customer incivility is regarded as being related to this phenomenon. In ...order to obtain a better understanding about the relationships between customer incivility, restaurant frontline service employee burnout and their turnover, information was obtained from 228 frontline service employees working in 28 independent Florida-based restaurants. Employees provided details of their experiences and attitudes regarding customer incivility as well as information on their job burnout and turnover intention. Hierarchical linear modeling was used for data analysis. Results confirmed that customer incivility has a positive relationship with restaurant frontline service employee job burnout. Further, this study found that the relationship between customer incivility and turnover intention through job burnout was fully mediated. The moderating roles that organizational support and supervisory support play upon the relationships between customer incivility and burnout were also investigated. Results confirmed that organizational and supervisory support moderates the relationship between customer incivility and burnout. Managerial implications for developing effective employee management strategies are provided for restaurant managers.
Following the trend of miniaturization as per Moore's law, and facing the strong demand of next‐generation electronic devices that should be highly portable, wearable, transplantable, and ...lightweight, growing endeavors have been made to develop novel flexible data storage devices possessing nonvolatile ability, high‐density storage, high‐switching speed, and reliable endurance properties. Nonvolatile organic data storage devices including memory devices on the basis of floating‐gate, charge‐trapping, and ferroelectric architectures, as well as organic resistive memory are believed to be favorable candidates for future data storage applications. In this Review, typical information on device structure, memory characteristics, device operation mechanisms, mechanical properties, challenges, and recent progress of the above categories of flexible data storage devices based on organic nanoscaled materials is summarized.
The recent developments of a series of flexible organic nonvolatile data storage devices, from transistor based memory, including floating‐gate, charge‐trapping, and ferroelectric architectures, to resistive memory are summarized. The challenges and perspectives in this field are also discussed. The achievement of these fantastic nonvolatile memory applications will set a new agenda for the design of novel data storage.
Recently, conductive metal−organic frameworks (MOFs) as the active material have provided broad prospects for electronic device application. The positioning technologies for MOFs enable the ...fabrication of novel microstructures, which can modulate the morphology of the material and tune the properties for the targeted application. Herein, a template‐method is used to synthesize the hierarchical structure of MOF hybrid array (MHA) on copper mesh (MHA@Mesh) for flexible sensor. Finite element method (FEM) results indicate that the 3D hierarchical MHA@Mesh can mimic the micro/nanoscale structure of human skin, which enables an interlocking contact. MHA@Mesh‐based flexible sensor presents rapid response rate (<1 ms) and high sensitivity (up to 307 kPa−1) which is 20 times higher than that of MHA@Foil‐based sensor (15 kPa−1). The flexible pressure device could be applied to monitor the finger motion and human pulses. Moreover, the music recognition can be performed by integrating the MOFs hardware sensors with machine learning algorithms. Overall, this design concept of 3D hierarchical microarray structures demonstrates potential in the fields of wearable technologies and human–machine interfaces.
A metal–organic framework hybrid array on a copper mesh with a hierarchical structure is synthesized and employed as the active layer of a resistive tactile sensor. Finite element method study reveals the mechanism of pressure‐dependent contact area modulation. The sensor can monitor biophysical signals and realize music recognition owing to the high sensitivity and stability.
•Overall characteristics of DME fueled engine are reviewed.•Fuel properties characteristics of DME are introduced.•New technologies for DME vehicle are systemically reviewed.•Research trends for the ...development of DME vehicle in the world are introduced.
From the perspectives of environmental conservation and energy security, dimethyl-ether (DME) is an attractive alternative to conventional diesel fuel for compression ignition (CI) engines. This review article deals with the application characteristics of DME in CI engines, including its fuel properties, spray and atomization characteristics, combustion performance, and exhaust emission characteristics. We also discuss the various technological problems associated with its application in actual engine systems and describe the field test results of developed DME-fueled vehicles. Combustion of DME fuel is associated with low NOx, HC, and CO emissions. In addition, PM emission of DME combustion is very low due to its molecular structure. Moreover, DME has superior atomization and vaporization characteristics than conventional diesel. A high exhaust gas recirculation (EGR) rate can be used in a DME engine to reduce NOx emission without any increase in soot emission, because DME combustion is essentially soot-free. To decrease NOx emission, engine after-treatment devices, such as lean NOx traps (LNTs), urea-selective catalytic reduction, and the combination of EGR and catalyst have been applied. To use DME fuel in automotive vehicles, injector design, fuel feed pump, and the high-pressure injection pump have to be modified, combustion system components, including sealing materials, have to be rigorously designed. To use DME fuel in the diesel vehicles, more research is required to enhance its calorific value and engine durability due to the low lubricity of DME, and methods to reduce NOx emission are also required.
Human beings have a greater need to pursue life and manage personal or family health in the context of the rapid growth of artificial intelligence, big data, the Internet of Things, and 5G/6G ...technologies. The application of micro biosensing devices is crucial in connecting technology and personalized medicine. Here, the progress and current status from biocompatible inorganic materials to organic materials and composites are reviewed and the material‐to‐device processing is described. Next, the operating principles of pressure, chemical, optical, and temperature sensors are dissected and the application of these flexible biosensors in wearable/implantable devices is discussed. Different biosensing systems acting in vivo and in vitro, including signal communication and energy supply are then illustrated. The potential of in‐sensor computing for applications in sensing systems is also discussed. Finally, some essential needs for commercial translation are highlighted and future opportunities for flexible biosensors are considered.
Flexible biosensors (pressure, optical, temperature, and electrochemical sensors) prepared from various biocompatible materials have the capability to monitor physiological signals such as heart rate, temperature, and body fluid markers. Sophisticated wearable/implantable sensors and systems for optimizing every aspect of the personal health and performance can be achieved through rational design of functional material and device architecture, as well as the use of advanced processing/integration approaches.
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