The mechanisms underlying gene repression and silencers are poorly understood. Here we investigate the hypothesis that H3K27me3-rich regions of the genome, defined from clusters of H3K27me3 peaks, ...may be used to identify silencers that can regulate gene expression via proximity or looping. We find that H3K27me3-rich regions are associated with chromatin interactions and interact preferentially with each other. H3K27me3-rich regions component removal at interaction anchors by CRISPR leads to upregulation of interacting target genes, altered H3K27me3 and H3K27ac levels at interacting regions, and altered chromatin interactions. Chromatin interactions did not change at regions with high H3K27me3, but regions with low H3K27me3 and high H3K27ac levels showed changes in chromatin interactions. Cells with H3K27me3-rich regions knockout also show changes in phenotype associated with cell identity, and altered xenograft tumor growth. Finally, we observe that H3K27me3-rich regions-associated genes and long-range chromatin interactions are susceptible to H3K27me3 depletion. Our results characterize H3K27me3-rich regions and their mechanisms of functioning via looping.
Sodium metal is a promising anode, but uneven Na deposition with a dendrite growth seriously impedes its application. Herein, a fibrous hydroxylated MXene/carbon nanotubes (h‐Ti3C2/CNTs) composite is ...designed as a scaffold for dendrite‐free Na metal electrodes. This composite displays fast Na+/electron transport kinetics and good thermal conductivity and mechanical properties. The h‐Ti3C2 contains abundant sodiophilic functional groups, which play a significant role in inducing homogeneous nucleation of Na. Meanwhile, CNTs provide high tensile strength and ease of film‐forming. As a result, h‐Ti3C2/CNTs exhibit a high average Coulombic efficiency of 99.2 % and no dendrite after 1000 cycles. The h‐Ti3C2/CNTs/Na based symmetric cells show a long lifespan over 4000 h at 1.0 mA cm−2 with a capacity of 1.0 mAh cm−2. Furthermore, Na‐O2 batteries with a h‐Ti3C2/CNTs/Na anode exhibit a low potential gap of 0.11 V after an initial 70 cycles.
A friend to sodium: A fibrous hydroxylated h‐Ti3C2/carbon nanotubes composite is designed as a scaffold for dendrite‐free Na metal electrodes. It displays fast Na+/electron transport kinetics, high sodiophilicity, and satisfactory thermal conductivity and mechanical properties.
Environment perception is one of the major issues in autonomous driving systems. In particular, effective and robust drivable road region detection still remains a challenge to be addressed for ...autonomous vehicles in multi-lane roads, intersections and unstructured road environments. In this paper, a computer vision and neural networks-based drivable road region detection approach is proposed for fixed-route autonomous vehicles (e.g., shuttles, buses and other vehicles operating on fixed routes), using a vehicle-mounted camera, route map and real-time vehicle location. The key idea of the proposed approach is to fuse an image with its corresponding local route map to obtain the map-fusion image (MFI) where the information of the image and route map act as complementary to each other. The information of the image can be utilized in road regions with rich features, while local route map acts as critical heuristics that enable robust drivable road region detection in areas without clear lane marking or borders. A neural network model constructed upon the Convolutional Neural Networks (CNNs), namely FCN-VGG16, is utilized to extract the drivable road region from the fused MFI. The proposed approach is validated using real-world driving scenario videos captured by an industrial camera mounted on a testing vehicle. Experiments demonstrate that the proposed approach outperforms the conventional approach which uses non-fused images in terms of detection accuracy and robustness, and it achieves desirable robustness against undesirable illumination conditions and pavement appearance, as well as projection and map-fusion errors.
The rechargeable Li-CO
2
battery has been receiving significant attention owing to its merits of high energy density and the efficient utilization of CO
2
. However, the widely application is plagued ...by severe security risks, such as leakage, flammability and lithium dendrites growth due to the use of liquid organic electrolytes. Here, a composite solid state electrolyte consisting of polyethylene oxide (PEO) and 20 wt.% Li
7
La
3
Zr
1.4
Ta
0.6
O
12
(LLZTO) was prepared and first introduced into Li-CO
2
battery to solve the problems. The composite solid state electrolyte exhibited high ionic conductivity (1.03 × 10
−1
S·cm
−1
at 70 °C), wide electrochemical window (5 V vs. Li
+
/Li), good mechanical properties and excellent flexibility. Ultimately, the Li symmetric cell with PEO/LLZTO composite solid state electrolyte can operate 1,500 h at a current density of 0.1 mA·cm
−2
. The assembled all-solid-state Li-CO
2
battery behaved a long cycle life of 70 cycles at a current density of 100 mA·g
−1
with fixed capacity of 1,000 mAh·g
−1
. Our work provides new perspective to develop rechargeable all-solid-state Li-CO
2
batteries.
Aiming at the problem of degradation of correlation quality caused by excessive idealization of noise in the traditional track correlation model, this paper introduces the uncertainty theory in the ...track correlation process, and uses the uncertainty normal distribution in the theory to describe the noise in the track correlation, thus proposing a new track correlation model based on the uncertainty distribution. The motion equation and observation equation are reconstructed under three motion states uniform velocity, uniform acceleration, and variable acceleration. At the same time, this paper also uses a variety of traditional noises (including Gaussian noise) to simulate various complex noise environments, and uses a variety of algorithms to solve the model in this paper and the traditional model, and finally compares the performance of the two models under the same conditions, thus verifying the superiority and applicability of the uncertain normal correlation model from a variety of angles to the greatest extent.
Chromatin interactions play important roles in regulating gene expression. However, the availability of genome-wide chromatin interaction data is limited. We develop a computational method, chromatin ...interaction neural network (ChINN), to predict chromatin interactions between open chromatin regions using only DNA sequences. ChINN predicts CTCF- and RNA polymerase II-associated and Hi-C chromatin interactions. ChINN shows good across-sample performances and captures various sequence features for chromatin interaction prediction. We apply ChINN to 6 chronic lymphocytic leukemia (CLL) patient samples and a published cohort of 84 CLL open chromatin samples. Our results demonstrate extensive heterogeneity in chromatin interactions among CLL patient samples.
Reasonable financing structure is of great significance to the healthy development of enterprises. It can improve the operation and management of enterprises, enhance the financing ability of ...enterprises and promote the effective allocation of market resources. In this paper, the analysis of the capital structure of Sichuan Changhong found that the capital structure of Sichuan Changhong is not reasonable enough, in view of this problem to put forward some suggestions and improvement measures, not only can make Sichuan Changhong close to the optimal capital structure, improve its own quality and investment value, but also can enhance investors’ confidence in Sichuan Changhong.
In this study, we extend traditional (single-target) hybrid systems to multi-target hybrid systems with a focus on the multi-maneuvering-target tracking system. This system consists of a continuous ...state, a discrete and switchable state, and a discrete, time-constant, and unique state. By defining a new generalized labeled multi-Bernoulli density, we prove that it is closed under the Chapman-Kolmogorov prediction and Bayes update for multi-target hybrid systems. In other words, we provide the exact derivation of a solution to this system, i.e., the multi-model generalized labeled multi-Bernoulli filter, which has been developed without strict proof.
Rechargeable aprotic lithium-oxygen (Li-O2) batteries have attracted significant interest in recent years owing to their ultrahigh theoretical capacity, low cost, and environmental friendliness. ...However, the further development of Li-O2 batteries is hindered by some ineluctable issues, such as severe parasitic reactions, low energy efficiency, poor rate capability, short cycling life and potential safety hazards, which mainly stem from the high charging overpotential in the positive electrode side. Thus, it is of great significance to develop high-performance catalysts for the positive electrode in order to address these issues and to boost the commercialization of Li-O2 batteries. In this review, three main categories of catalyst for the positive electrode of Li-O2 batteries, including carbon materials, noble metals and their oxides, and transition metals and their oxides, are systematically summarized and discussed. We not only focus on the electrochemical performance of batteries, but also pay more attention to understanding the catalytic mechanism of these catalysts for the positive electrode. In closing, opportunities for the design of better catalysts for the positive electrode of high-performance Li-O2 batteries are discussed.
Organic carbonyl electrode materials have shown great prospects for rechargeable batteries in view of their high capacity, flexible designability, and sustainable production. However, organic ...carbonyl electrode materials still suffer from unsatisfactory electrochemical performance, which is highly relevant to their redox processes. Herein, an in‐depth understanding on redox processes and the correlated electrochemical performance of organic carbonyl electrode materials is provided. The redox processes discussed mainly involve molecular structure evolution (intermediates), crystal structure evolution (phase transition), and charge storage mechanisms. The properties of intermediates can affect voltage, cycling stability, reversible capacity, and rate performance of batteries. Moreover, the reversible capacity/cycling stability and rate performance would be also influenced by phase transition and charge storage mechanisms (diffusion‐ or surface‐controlled), respectively. To accelerate the practical applications of organic carbonyl electrode materials, future work should focus on developing more in situ or operando characterization techniques and further understanding the intrinsic relationships between redox processes and performance. It is hoped that the work discussed herein will stimulate more attention to the detailed redox processes and their correlations with the performance of organic carbonyl electrode materials in rechargeable batteries.
Organic carbonyl compounds have been considered as promising electrode materials for high‐performance rechargeable batteries. However, their redox processes and performance need to be fully understood. An in‐depth understanding on redox processes and the correlated electrochemical performance of organic carbonyl electrode materials is provided, with the aim of promoting their practical applications in the foreseeable future.
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