Publications by authors named "Xikui Liu"

Dual-atom catalysts featuring synergetic dinuclear active sites, have the potential of breaking the linear scaling relationship of the well-established single-atom catalysts for oxygen reduction reaction; however, the design of dual-atom catalysts with rationalized local microenvironment for high activity and selectivity remains a great challenge. Here we design a bisalphen ladder polymer with well-defined densely populated binuclear cobalt sites on Ketjenblack substrates. The strong electron coupling effect between the fully-conjugated ladder structure and carbon substrates enhances the electron transfer between the cobalt center and oxygen intermediates, inducing the low-to-high spin transition for the 3d electron of Co(II).

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This paper concentrates on the finite-time H∞ control problem for a type of stochastic discrete-time Markovian jump systems, characterized by time-delay and partly unknown transition probabilities. Initially, a stochastic finite-time (SFT) H∞ state feedback controller and an SFT H∞ observer-based state feedback controller are constructed to realize the closed-loop control of systems. Then, based on the Lyapunov-Krasovskii functional (LKF) method, some sufficient conditions are established to guarantee that closed-loop systems (CLSs) satisfy SFT boundedness and SFT H∞ boundedness.

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Article Synopsis
  • Bacterial infections are becoming a major global health issue, primarily treated by antibiotics, but their overuse has led to antibiotic resistance and higher death rates.
  • Bacteria's ability to form biofilms complicates treatment, as these structures protect them from antibiotics and environmental harm, resulting in persistent infections and device damage.
  • The review emphasizes the need for alternative antimicrobial agents, highlighting the potential of nano-antibacterial materials and exploring innovative strategies for antibiotic-free disinfection approaches in the future.
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The mechanism of sex determination in chickens, especially the molecular mechanism of female ovarian development, has not yet been fully elucidated. Previous studies have shown that , which is associated with ovarian development in mammals, might have a conserved role in chickens. In this study, we systematically investigated the spatiotemporal expression pattern of in various tissues, especially gonads, of male and female chicken embryos using qPCR and Western blotting, and we explored its correlation with the expression of key genes in the estrogen pathway using drug treatment or gene overexpression in vivo and in vitro.

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The sex chromosomes of birds are designated Z and W. The male is homogamous (ZZ), and the female is heterogamous (ZW). The chicken W chromosome is a degenerate version of the Z chromosome and harbors only 28 protein-coding genes.

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This paper deals with the problems of finite-time boundedness (FTB) and H∞ FTB for time-delay Markovian jump systems with a partially unknown transition rate. First of all, sufficient conditions are provided, ensuring the FTB and H∞ FTB of systems given by linear matrix inequalities (LMIs). A new type of partially delay-dependent controller (PDDC) is designed so that the resulting closed-loop systems are finite-time bounded and satisfy a given H∞ disturbance attenuation level.

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Metal-porphyrins or metal-phthalocyanines-based organic frameworks (POFs), an emerging family of metal-N-C materials, have attracted widespread interest for application in electrocatalysis due to their unique metal-N coordination structure, high conjugated π-electron system, tunable components, and chemical stability. The key challenges of POFs as high-performance electrocatalysts are the need for rational design for porphyrins/phthalocyanines building blocks and an in-depth understanding of structure-activity relationships. Herein, the synthesis methods, the catalytic activity modulation principles, and the electrocatalytic behaviors of 2D/3D POFs are summarized.

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Ruthenium (Ru)-based catalysts have displayed compelling hydrogen evolution activities, which hold the promising potential to substitute platinum in alkaline H -evolution. In the challenging alkaline electrolytes, the water-dissociation process involves multistep reactions, while the profound origin and intrinsic factors of diverse Ru species on water-dissociation pathways and reaction principles remain ambiguous. Here the fundamental origin of water-dissociation pathways of Ru-based catalysts in alkaline media to be from their unique electronic structures in complex coordination environments are disclosed.

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Cancer is one of the major contributors to human mortality and has a serious influence on human survival and health. In biomedical research, the identification of cancer driver genes (cancer drivers for short) is an important task; cancer drivers can promote the progression and generation of cancer. To identify cancer drivers, many methods have been developed.

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Tuning the microenvironment and electronic structure of support materials is essential strategy to induce electron transfer between supports and active centers, which is of great importance in optimizing catalytic kinetics. In this study, the molybdenum oxycarbide supported Rh-clusters are synthesized with modulated interstitial C-O microenvironments (Rh/MoOC) for promoting efficient hydrogen evolution in water splitting. Both electronic structure characterizations and theoretical calculations uncover the apparent charge transfer from Rh to MoOC, which optimizes the d-band center, H O adsorption energy, and hydrogen binding energy, thus enhancing its intrinsic hydrogen-evolving activities.

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Article Synopsis
  • Researchers are exploring new ways to improve lithium-sulfur battery cathodes by enhancing the reduction catalysis of insoluble lithium sulfide (Li S), which can help address the shuttle effect and improve battery efficiency.
  • The study highlights that the speed and effectiveness of this reduction process are influenced by the spin density and magnetic properties of ferromagnetic single-atom materials, specifically iron-based catalysts.
  • Experimental results show that Fe-N-based cathodes demonstrate the quickest lithium sulfide deposition and lowest energy barriers, suggesting that leveraging the magnetic properties of these materials could significantly enhance battery lifespan.
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Tumor stratification plays an important role in cancer diagnosis and individualized treatment. Recent developments in high-throughput sequencing technologies have produced huge amounts of multi-omics data, making it possible to stratify cancer types using multiple molecular datasets. We introduce a Network Embedding method for tumor Stratification by integrating Multi-omics data.

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Developing reactive oxygen species (ROS)-scavenging nanostructures to protect and regulate stem cells has emerged as an intriguing strategy for promoting tissue regeneration, especially in trauma microenvironments or refractory wounds. Here, an electronic modulated metal oxide is developed via Mn atom substitutions in Co O nanocrystalline (Mn-Co O ) for highly efficient and multifaceted catalytic ROS-scavenging to reverse the fates of mesenchymal stem cells (MSCs) in oxidative-stress microenvironments. Benefiting from the atomic Mn-substitution and charge transfer from Mn to Co, the Co site in Mn-Co O displays an increased ratio of Co /Co and improved redox properties, thus enhancing its intrinsic and broad-spectrum catalytic ROS-scavenging activities, which surpasses most of the currently reported metal oxides.

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Compared to single-drug therapy, drug combinations have shown great potential in cancer treatment. Most of the current methods employ genomic data and chemical information to construct drug-cancer cell line features, but there is still a need to explore methods to combine topological information in the protein interaction network (PPI). Therefore, we propose a network-embedding-based prediction model, NEXGB, which integrates the corresponding protein modules of drug-cancer cell lines with PPI network information.

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Owing to their rich surface chemistry, high conductivity, tunable bandgap, and thermal stability, structured 2D transition-metal carbides, nitrides, and carbonitrides (MXenes) with modulated atomic environments have emerged as efficient electrochemical energy conversion systems in the past decade. Herein, the most recent advances in the engineering of tunable structured MXenes as a powerful new platform for electrocatalytic energy conversion are comprehensively summarized. First, the state-of-the-art synthetic and processing methods, tunable nanostructures, electronic properties, and modulation principles of engineering MXene-derived nanoarchitectures are focused on.

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A surge in research has occurred because of current developments in single-cell technologies. Above all, single-cell Assay for Transposase-Accessible Chromatin with high throughput sequencing (scATAC-seq) is a popular approach of analyzing chromatin accessibility differences at the level of single cell, either within or between groups. As a result, it is critical to examine cell heterogeneity at a previously unseen level and to identify both recognized and unknown cell types.

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Article Synopsis
  • * The review highlights advancements in design, synthesis, characterization, and theoretical analysis of SASs, detailing how different structures affect reaction pathways and performance in electrolysis.
  • * It concludes by discussing the mechanisms by which SAS structures enhance electrocatalysis and outlines future challenges and perspectives to promote the use of SAS catalysts in water-splitting applications.
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The main concern of this paper is finite-time stability (FTS) for uncertain discrete-time stochastic nonlinear systems (DSNSs) with time-varying delay (TVD) and multiplicative noise. First, a Lyapunov-Krasovskii function (LKF) is constructed, using the forward difference, and less conservative stability criteria are obtained. By solving a series of linear matrix inequalities (LMIs), some sufficient conditions for FTS of the stochastic system are found.

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Li-S batteries are considered to be the most promising next-generation advanced energy-storage systems. However, the sluggish reaction kinetics and the "shuttle effect" of lithium polysulfides (LiPSs) severely limit their battery performances. To overcome the complex and multiphase sulfur redox chemistry of LiPSs, in this study, we propose a new type of cobalt-based double catalytic sites (DCSs) codoped mesoporous carbon to immobilize and reversibly catalyze the LiPS intermediates in the cycling process, thus eliminating the shuttle effect and improving the charge-discharge kinetics.

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Water electrolysis is considered to be one of the most promising technologies to produce clean fuels. However, its extensive realization critically depends on the progress in cost-effective and high-powered oxygen evolution reaction (OER) electrocatalysts. As a member of the big family of two-dimensional (2D) materials, nanostructured layered double hydroxides (nLDHs) have made significant processes and continuous breakthroughs for OER electrocatalysis.

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Article Synopsis
  • The text indicates that a correction has been made to a previously published article, specifically one that can be found with the DOI: 10.1039/C9SC00975B.* -
  • This suggests that there may have been errors or omissions in the original publication that needed to be addressed.* -
  • The correction is important for maintaining the accuracy and integrity of the scientific record associated with that article.*
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Due to the dynamic nature of networks and high mobility of molecular chains, self-healing elastomers are usually confronted with the trade-off between self-healing efficiency and mechanical properties. Herein, a self-healing ionomer with both high mechanical performance and high self-healing efficiency has been successfully developed by grafting bromobutyl rubber (BIIR) with pyridine-based derivatives. Interestingly, the substituents on the pyridine ring can be used to regulate the interaction forces of ionic clusters and molecular dynamics.

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  • The paper explores the Pareto game for continuous-time stochastic systems using approximate/adaptive dynamic programming (ADP) methods.
  • It introduces a model-based online iterative algorithm that converges to a Pareto efficient solution but relies on complete system parameters.
  • The authors also develop a model-free iterative equation using the ADP algorithm, proving that both model-free and model-based approaches yield the same solutions, with simulations demonstrating the algorithm's effectiveness.
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Framework crystallization is an unresolved challenge in the chemistry of covalent organic frameworks (COFs) due to the poorly controlled simultaneous polymerization and crystallization processes. Here, we report the first morphogenesis of COF mesocrystals with two-dimensional hexagonal p6m symmetry through the combination of alkyl amine as a dynamic modulator and 2,4,6- triformylresorcinol imine as an asymmetrical building block. The amine modulator depresses the lateral growth of 2D sheets, and the slow kinetics combined with the asymmetrical conformation of 2,4,6-triformylresorcinol imine lead to the formation of transient imine macrocycles, which further undergo mesoscale self-assembly into nanotubular structures.

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