Abstract
A diffusive memristor is a promising building block for brain‐inspired computing hardware. However, the randomness in the device relaxation dynamics limits the wide‐range adoption of ...diffusive memristors in large arrays. In this work, the device stack is engineered to achieve a much‐improved uniformity in the relaxation time (standard deviation σ reduced from ≈12 to ≈0.32 ms). The memristor is further connected with a resistor or a capacitor and the relaxation time is tuned between 1.13 µs and 1.25 ms, ranging from three orders of magnitude. The hierarchy of time surfaces (HOTS) algorithm, to utilize the tunable and uniform relaxation behavior for spike generation, is implemented. An accuracy of 77.3% is achieved in recognizing moving objects in the neuromorphic MNIST (N‐MNIST) dataset. The work paves the way for building emerging neuromorphic computing hardware systems with ultralow power consumption.
Several recent works have studied mobile vehicle scheduling to recharge sensor nodes via wireless energy transfer technologies. Unfortunately, most of them overlooked important factors of the ...vehicles' moving energy consumption and limited recharging capacity, which may lead to problematic schedules or even stranded vehicles. In this paper, we consider the recharge scheduling problem under such important constraints. To balance energy consumption and latency, we employ one dedicated data gathering vehicle and multiple charging vehicles. We first organize sensors into clusters for easy data collection, and obtain theoretical bounds on latency. Then we establish a mathematical model for the relationship between energy consumption and replenishment, and obtain the minimum number of charging vehicles needed. We formulate the scheduling into a Profitable Traveling Salesmen Problem that maximizes profit - the amount of replenished energy less the cost of vehicle movements, and prove it is NP-hard. We devise and compare two algorithms: a greedy one that maximizes the profit at each step; an adaptive one that partitions the network and forms Capacitated Minimum Spanning Trees per partition. Through extensive evaluations, we find that the adaptive algorithm can keep the number of nonfunctional nodes at zero. It also reduces transient energy depletion by 30-50 percent and saves 10-20 percent energy. Comparisons with other common data gathering methods show that we can save 30 percent energy and reduce latency by two orders of magnitude.
With the rapid development of digital art and machine science and technology, the production form of modern animation tends to be diversified, and with the important role of animation color in the ...animation film foil and rendering, more and more attention was paid by the animation design industry. Computer graphic technology is a new type of artistic creation method, and its birth and development are closely related to computer technology. The purpose of this paper is to make some analysis and induction from the perspective of science and technology and culture and to explore the application of Photoshop graphics and image processing technology in the field of animation. First, the definition of “animation” and the extension of the animation category are introduced. Then, the main functions of Photoshop image processing technology are described in detail. According to the research content, this paper designs a self-made experimental short film “future city.” After the simulation of experimental animation film and the setting and positioning of the experimental scene, Photoshop software was used to show the animation scene. The experimental results show that the color changes in the short film “future city.” After the saturation of sunny scenery is reduced by 3 points and the brightness is reduced by 20 points and the filter, mode change, and color adjustment are carried out, a complete rainy scenery can be obtained. The self-made experimental short film has guiding significance for the creation and practice.
Phasor measurement units (PMUs) are being widely installed in the transmission grid. Many power system applications based on PMUs have been developed or are under development in academia and ...industry. For those applications, data latency is often a critical factor that affects their performance thus making the topology of the communication network that exchanges real-time data between the control center (CC) and substations (SS) of vital importance. This paper introduces a method to conceptualize and analyze possible communication topologies by simulating them in Network Simulator 3 (NS3). Moreover, a new algorithm is developed to optimize the clustering of substations in such a way that the data latency performance of the decentralized communication topology can meet the requirements for PMU based applications. To validate the proposed methodology, the IEEE 118-bus system is used as the test case. A PMU based wide-area controller for transient stability is simulated in the MATLAB Simulink to validate the proposed communication topologies. It is concluded from the simulation results that the decentralized communication topology at a lower cost designed by optimizing the substation cluster boundaries can be an alternative choice and can help PMU based applications achieve good performance by limiting data latency to an acceptable level. Also, this paper can provide a technical guidance for power utilities choosing the most appropriate communication network for the PMU based real-time applications.
The application of virtual reality has become increasingly extensive as this technology has developed. In dental education, virtual reality is mainly used to assist or replace traditional methods of ...teaching clinical skills in preclinical training for several subjects, such as endodontics, prosthodontics, periodontics, implantology, and dental surgery. The application of dental simulators in teaching can make up for the deficiency of traditional teaching methods and reduce the teaching burden, improving convenience for both teachers and students. However, because of the technology limitations of virtual reality and force feedback, dental simulators still have many hardware and software disadvantages that have prevented them from being an alternative to traditional dental simulators as a primary skill training method. In the future, when combined with big data, cloud computing, 5G, and deep learning technology, dental simulators will be able to give students individualized learning assistance, and their functions will be more diverse and suitable for preclinical training. The purpose of this review is to provide an overview of current dental simulators on related technologies, advantages and disadvantages, methods of evaluating effectiveness, and future directions for development.
In Eukaryotes, inositol polyphosphates (InsPs) represent a large family of secondary messengers and play crucial roes in various cellular processes. InsPs are synthesized through a series of ...pohophorylation reactions catalyzed by various InsP kinases in a sequential manner. Inositol 1,4,5-trisphosphate 3-kinase (IP3 3-kinase/IP3K), one member of InsP kinase, plays important regulation roles in InsPs metabolism by specifically phosphorylating inositol 1,4,5-trisphosphate (IP3) to inositol 1,3,4,5-tetrakisphosphate (IP4) in animal cells. IP3Ks were widespread in fungi, plants and animals. However, its evolutionary history and patterns have not been examined systematically.
A total of 104 and 31 IP3K orthologues were identified across 57 plant genomes and 13 animal genomes, respectively. Phylogenetic analyses indicate that IP3K originated in the common ancestor before the divergence of fungi, plants and animals. In most plants and animals, IP3K maintained low-copy numbers suggesting functional conservation during plant and animal evolution. In Brassicaceae and vertebrate, IP3K underwent one and two duplication events, respectively, resulting in multiple gene copies. Whole-genome duplication (WGD) was the main mechanism for IP3K duplications, and the IP3K duplicates have experienced functional divergence. Finally, a hypothetical evolutionary model for the IP3K proteins is proposed based on phylogenetic theory.
Our study reveals the evolutionary history of IP3K proteins and guides the future functions of animal, plant, and fungal IP3K proteins.
Owing to their theoretical energy density of 2600 Wh kg−1, lithium–sulfur batteries represent a promising future energy storage device to power electric vehicles. However, the practical applications ...of lithium–sulfur batteries suffer from poor cycle life and low Coulombic efficiency, which is attributed, in part, to the polysulfide shuttle and Li dendrite formation. Suppressing Li dendrite growth, blocking the unfavorable reaction between soluble polysulfides and Li, and improving the safety of Li–S batteries have become very important for the development of high‐performance lithium sulfur batteries. A comprehensive review of various strategies is presented for enhancing the stability of the anode of lithium sulfur batteries, including inserting an interlayer, modifying the separator and electrolytes, employing artificial protection layers, and alternative anodes to replace the Li metal anode.
Anodes play an important role in resolving the issues of conventional lithium sulfur batteries. The most recent progress in anodes for lithium–sulfur batteries is introduced. To suppress the corrosion reaction that occurs and the formation of Li dendrites on the surface of lithium metal, various strategies are summarized. Employing alternative anodes for sulfur‐based rechargeable batteries is also discussed.
High‐mobility group protein A2 (HMGA2) is highly expressed in hepatocellular carcinoma (HCC) cells and contributes to tumor metastasis and poor patient survival. However, the molecular mechanism ...through which HMGA2 is transcriptionally regulated in HCC cells remains largely unclear. Here, we showed that the expression HMGA2 was upregulated in HCC, and that elevated HMGA2 could promote tumor metastasis. Incubation of HCC cells with epidermal growth factor (EGF) could promote the expression of HMGA2 mRNA and protein. Mechanistic studies suggested that EGF can phosphorylate p300 at Ser1834 residue through the PI3K/Akt signaling pathway in HCC cells. Knockdown of p300 can reverse EGF‐induced HMGA2 expression and histone H3‐K9 acetylation, whereas a phosphorylation‐mimic p300 S1834D mutant can stimulate HMGA2 expression as well as H3‐K9 acetylation in HCC cells. Furthermore, we identified that p300‐mediated H3‐K9 acetylation participates in EGF‐induced HMGA2 expression in HCC. In addition, the levels of H3‐K9 acetylation positively correlated with the expression levels of HMGA2 in a chemically induced HCC model in rats and human HCC specimens.
We first showed that EGF can induce p300 phosphorylation at the Ser1834 site through activation of the PI3K/AKT signaling pathway in hepatocellular carcinoma; p300 subsequently catalyzes histone H3 acetylation at K9 residues, leading to HMGA2 transcription in HCC
A diffusion barrier at the transition zone enables the compartmentalization of signaling molecules by cilia. The BBSome and the small guanosine triphosphatase Arl6, which triggers BBSome coat ...polymerization, are required for the exit of activated signaling receptors from cilia, but how diffusion barriers are crossed when membrane proteins exit cilia remains to be determined. In this study, we found that activation of the ciliary G protein-coupled receptors (GPCRs) Smoothened and SSTR3 drove the Arl6-dependent assembly of large, highly processive, and cargo-laden retrograde BBSome trains. Single-molecule imaging revealed that the assembly of BBSome trains enables the lateral transport of ciliary GPCRs across the transition zone. However, the removal of activated GPCRs from cilia was inefficient because a second periciliary diffusion barrier was infrequently crossed. We conclude that exit from cilia is a two-step process in which BBSome/Arl6 trains first move activated GPCRs through the transition zone before a periciliary barrier can be crossed.
PDF
