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This work investigated the effect of ZrB2 content on phase composition, relative density, microstructure, and mechanical performance of Si3N4 ceramics prepared by Si nitridation and hot‐pressing method. Si3N4 ceramics were fabricated using Si powder by nitridation and hot‐pressing process. Results showed that the addition of ZrB2 enhanced the transformation of α‐Si3N4 into β‐Si3N4 phase during nitridation, resulting in a greater fraction of β‐Si3N4 (above 90 wt.%) phase in Si3N4 ceramics with ZrB2 after hot‐pressing. In contrast, ceramics without ZrB2 had a lower ratio of β‐Si3N4 (40.4 wt.%). The use of 2.5 vol.% ZrB2 yielded a significant bimodal microstructure and increased fracture toughness to 5.0 ± 0.2 MPa·m1/2, but decreased Vickers hardness to 16.4 ± 0.5 GPa. However, increasing the ZrB2 content to 5 vol.% and 10 vol.% led to a massive formation of equiaxed coarse β‐Si3N4 grains and a significant decrease in Vickers hardness and fracture toughness. [ABSTRACT FROM AUTHOR]

The Lower Cambrian shale gas in the western Hubei area, South China has a great resource prospect, but the gas-in-place (GIP) content in different sedimentary facies varies widely, and the relevant mechanism has been not well understood. In the present study, two sets of the Lower Cambrian shale samples from theWells YD4 and YD5 in the western Hubei area, representing the deep-water shelf facies and shallowwater platform facies, respectively, were investigated on the differences of pore types, pore structure and methane adsorption capacity between them, and the main controlling factor and mechanism of their methane adsorption capacities and GIP contents were discussed. The results show that the organic matter (OM) pores in the YD4 shale samples are dominant, while the inorganic mineral (IM) pores in the YD5 shale samples are primary, with underdeveloped OM pores. The pore specific surface area (SSA) and pore volume (PV) of the YD4 shale samples are mainly from micropores and mesopores, respectively, while those of the YD5 shale samples are mainly from micropores and macropores, respectively. The methane adsorption capacity of the YD4 shale samples is significantly higher than that of the YD5 shale samples, with a maximum absolute adsorption capacity of 3.13 cm3/g and 1.31 cm3/g in average, respectively. Compared with the shallow-water platform shale, the deep-water shelf shale has a higher TOC content, a better kerogen type and more developed OM pores, which is the main mechanism for its higher adsorption capacity. The GIP content models based on two samples with a similar TOC content selected respectively from theWells YD4 and YD5 further indicate that the GIP content of the deep-water shelf shale is mainly 3-4 m3/t within a depth range of 1000e4000 m, with shale gas exploration and development potential, while the shallow-water platform shale has normally a GIP content of <1 m3/t, with little shale gas potential. Considering the geological and geochemical conditions of shale gas formation and preservation, the deep-water shelf facies is the most favorable target for the Lower Cambrian shale gas exploration and development in the western Hubei area, South China. [ABSTRACT FROM AUTHOR]

Nickel–iron oxyhydroxides are among the most active electrocatalysts, but their sluggish kinetic of oxygen evolution reaction (OER) limits the energy efficiency toward overall water splitting. Here, we present a "cascade electron transfer" strategy through spurring unidirectional electron transfer among different metal sites in Mn-doped FeNiOOH@FeNiP to boost OER and overall water splitting. The Mn doping induces a cascade electron transfer from Ni to Fe and then to Mn via metal-O-metal bridge, thus promoting the oxidation Ni and Fe centers, which in turn help charge transfer by increasing the covalency between metal-O bonds to optimize the bonding strength between metal and adsorbed oxygen species. Consequently, the optimal Mn–FeNiOOH@FeNiP delivers a fast OER kinetics (32.1 mV dec−1) along with a low overpotential of 215 mV@10 mA cm−2. Benefiting from the synergistic effect of high conductivity, large specific surface area, and favorable OER kinetics, the catalyst only requires a low cell voltage of 1.456 V to achieve 20 mA cm−2 for overall water splitting, superior to that of a commercial RuO2ǁPt/C catalyst. [ABSTRACT FROM AUTHOR]

Milk production is one of the most important economic utility of goats. Guanzhong dairy goat is a local dairy goat in Shaanxi Province of China and has high milk yield and quality. However, there are relatively few studies on molecular markers of milk production traits in Guanzhong dairy goats. In this study, we sequenced the whole genomes of 20 Guanzhong dairy goats, 10 of which had high milk yield (HM) and 10 of which had low milk yield (LM). We detected candidate signatures of selection in HM goats using Fst and π‐ratio statistics and identified several candidate genes including ANPEP, ADRA1A and PRKG1 associated with milk production. Our results provide the basis for molecular breeding of milk production traits in Guanzhong dairy goats. [ABSTRACT FROM AUTHOR]

The inability to locate device faults quickly and accurately has become prominent due to the large number of communication devices and the complex structure of secondary circuit networks in smart substations. Traditional methods are less efficient when diagnosing secondary equipment faults in smart substations, and deep learning methods have poor portability, high learning sample costs, and often require retraining a model. Therefore, a secondary equipment fault diagnosis method based on a graph attention network is proposed in this paper. All fault events are automatically represented as graph-structured data based on the K-nearest neighbors (KNNs) algorithm in terms of the feature information exhibited by the corresponding detection nodes when equipment faults occur. Then, a fault diagnosis model is established based on the graph attention network. Finally, partial intervals of a 220 kV intelligent substation are taken as an example to compare the fault localization effect of different methods. The results show that the method proposed in this paper has the advantages of higher localization accuracy, lower learning cost, and better robustness than the traditional machine learning and deep learning methods. [ABSTRACT FROM AUTHOR]

In this paper, we concentrate on design a bilateral preconditioning for all-at-once system from multidimensional time-space non-local evolution equations with a weakly singular kernel. Firstly, we propose an implicit difference scheme for this equation by employing an L2-type formula. Then, we prove the stability and the convergence of the proposed scheme. Based on such a numerical scheme, an L2-type all-at-once system is derived and solved in a parallel-in-space pattern. Based on the special structure of its coefficient matrix, we propose a bilateral preconditioning strategy to accelerate the convergence of Krylov subspace solvers. We theoretically show that the condition number of the preconditioned matrix is uniformly bounded by a constant. Several numerical examples are provided to test the proposed scheme and preconditioning technique. [ABSTRACT FROM AUTHOR]

In the past 15 years, the shale gas revolution and large-scale commercial developments in the United States have driven the exploration and development of shale plays worldwide. Among many factors affecting shale gas exploration potential, the gas-bearing properties of shale (quantity, storage state, composition) and their controlling factors are the essential research attracting wide attention in the academic community. This paper reviews the research progress on the retention mechanism, influencing factors, and evaluation methods for resource potential of the shale gas system, and proposes further research directions. Sorption is the main mechanism of gas retention in organic-rich shales; the gas is mainly stored in nanopores of shale in free and sorption states. The presence of water and nonhydrocarbon gases in pores can complicate the process and mechanism of methane (CH4) sorption, and the related theoretical models still need further development. The in-situ gas content and gasbearing properties of shale are governed by the geological properties (organic matter abundance, kerogen type, thermal maturity, mineral composition, diagenesis), the properties of fluids in pores (water, CH4, non-hydrocarbon gases), and geological conditions (temperature, pressure, preservation conditions) of the shale itself. For a particular basin or block, it is still challenging to define the main controlling factors, screen favorable exploration areas, and locate sweet spots. Compared to marine shales with extensive research and exploration data, lacustrine and marine-continental transitional shales are a further expanding area of investigation. Various methods have been developed to quantitatively characterize the in-situ gas content of shales, but all these methods have their own limitations, and more in-depth studies are needed to accurately evaluate and predict the in-situ gas content of shales, especially shales at deep depth. [ABSTRACT FROM AUTHOR]

In this study, the mechanism of the effect of ZrB 2 on phase transformation of Si 3 N 4 at a low temperature and the influence of its content on Si 3 N 4 -based ceramics were investigated. Previous study has shown that oxide impurities, i.e., B 2 O 3 and ZrO 2 on ZrB 2 particles, alone cannot contribute to phase transformation of Si 3 N 4 at a low temperature. But, the introduction of 0.5 vol% ZrB 2 into Si 3 N 4 ceramics can promote the α-β phase transformation of Si 3 N 4 , which is confirmed to be the role of boron by comparison of the experimental results obtained from the addition of 0.5 vol% Zr and 0.5 vol% B. Increasing the ZrB 2 content from 0 vol% to 2.5 vol% intensifies the α-β phase transformation while decreasing the α phase content of Si 3 N 4 -based ceramics, accompanied by a slight grain growth, leading to a decrease in hardness. At the same time, aspect ratio and the quantities of elongated grains per square micron increase, and thus the fracture toughness increases significantly. However, when the content of ZrB 2 increases to 5 vol%, the Si 3 N 4 -based ceramics not only have a substantial decrease in hardness, but also the fracture toughness fails to be effectively improved due to high porosity and the decrease in aspect ratio and the quantity of elongated grains per square micron. The current study demonstrates that the dense Si 3 N 4 -based ceramics with high hardness and toughness (hardness ∼19.9 ± 0.2 GPa, toughness ∼6.27 ± 0.19 MPa m1/2) can be prepared successfully at 1600 °C by introducing 0.5 vol% ZrB 2. [ABSTRACT FROM AUTHOR]

The Black–Scholes (B–S) equation has been recently extended as a kind of tempered time-fractional B–S equations, which becomes an interesting mathematical model in option pricing. In this study, we provide a fast numerical method to approximate the solution of the tempered time-fractional B–S model. To achieve high-order accuracy in space and overcome the weak initial singularity of exact solution, we combine the compact difference operator with L1-type approximation under nonuniform time steps to yield the numerical scheme. The convergence of the proposed difference scheme is proved to be unconditionally stable. Moreover, the kernel function in the tempered Caputo fractional derivative is approximated by sum-of-exponentials, which leads to a fast unconditionally stable compact difference method that reduces the computational cost. Finally, numerical results demonstrate the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

An optimized Schwarz domain decomposition method (DDM) for solving the local optical response model (LORM) is proposed in this paper. We introduce a hybridizable discontinuous Galerkin (HDG) scheme for the discretization of such a model problem based on a triangular mesh of the computational domain. The discretized linear system of the HDG method on each subdomain is solved by a sparse direct solver. The solution of the interface linear system in the domain decomposition framework is accelerated by a Krylov subspace method. We study the spectral radius of the iteration matrix of the Schwarz method for the LORM problems, and thus propose an optimized parameter for the transmission condition, which is different from that for the classical electromagnetic problems. The numerical results show that the proposed method is effective. [ABSTRACT FROM AUTHOR]

A method for detecting the surface defects of high reflection objects using phase deflection is proposed. The abrupt change in the surface gradient at the defect leads to the change in the fringe phase. Therefore, Gray code combined with a four-step phase-shift method was employed to obtain the surface gradients to characterize the defects. Then, through the double surface illumination model, the relationship between illumination intensity and phase was established. The causes of periodic error interference were analyzed, and the method of adjusting the fringe width to eliminate it was proposed. Finally, experimental results showed the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The convergence of sensing, computing, communication and control elements drives the traditional point-to-point control systems towards networked control systems. Sampled-data control systems, which focus on the significant interplay between sampling and control, play a critical role in modern networked control systems, including intelligent transportation systems, smart grids, and advanced manufacturing systems. This paper presents a survey of methods and trends in non-uniform sampled-data control systems, where sampling and control actions are performed in an aperiodic manner. First, some fundamental issues of both continuous- and discrete-time sampled-data control systems are discussed. Next, main methods in both continuous-time and discrete-time domains are elaborated, respectively. Then, event-triggered sampling, under which sampling is executed only when the system needs attention, is examined. Typical triggering mechanisms in the existing literature are reviewed and classified into four types according to different threshold functions. Furthermore, two applications in terms of automated vehicle platoons and islanded microgrids are provided to demonstrate that sampled-data control methods are capable to support relevant practical application scenarios. Finally, several challenging issues are envisioned to direct future research. [ABSTRACT FROM AUTHOR]

In this paper, we present a new block preconditioner for solving the saddle point linear systems. The proposed method is developed from an augmented reformulation of the saddle point problem into a new linear system with an almost block triangular coefficient matrix. Theoretical results are derived on the eigenvalue distribution of the preconditioned matrix, and an efficient algorithmic implementation is developed and presented. Several numerical examples are reported to support the theoretical findings and to illustrate the favourable convergence properties of the proposed preconditioner, also compared to other popular solvers for saddle point problems. [ABSTRACT FROM AUTHOR]

We have developed a method for constructing tricyclic [1,2‐a]indoles via nickel‐catalyzed intramolecular imine‐alkene coupling reactions. This method enables syntheses of 6‐5‐5 and 6‐5‐6 tricyclic [1,2‐a]indoles. The use of NIXantphos or DPPPent as a ligand and 4‐(trifluoromethyl)benzoic acid as a co‐catalyst is crucial for the reaction. The synthetic utility of the method was demonstrated by converting the product into useful indole amines. [ABSTRACT FROM AUTHOR]

The Bessel-Legendre inequality plays an important role in stability analysis of linear systems with time-varying delays. However, various integral vectors inherited from the Bessel-Legendre inequality bring some challenging issues, such as the construction of suitable augmented Lyapunov-Krasovskii functionals (LKFs); high-degree polynomial estimation on the derivative of the chosen LKF. This paper offers an overview of recent developments on these issues. First, an instructive review on the construction of suitable augmented LKFs catering for the use of the Bessel-Legendre inequality is given in detail. Second, an in-depth analysis and insightful understanding of high-degree polynomial inequalities on closed intervals are made. Third, recent results on reciprocally convex combination inequalities are briefly discussed. Finally, several challenging problems are presented for future research. [ABSTRACT FROM AUTHOR]

Polymerizing the narrow bandgap small-molecule architecture with a conjugated linking unit (or called the polymerized small molecule acceptors (PSMAs)) is a promising strategy to design polymer acceptors for efficient all polymer solar cells (all-PSCs). Currently, the fused-ring-based small molecule acceptors (SMAs) are preferred monomers to design efficient PSMAs, leaving the challenge of reducing the materials cost. In this work, we firstly employ nonfused-core SMA with simple synthetic procedures to design PSMAs (namely PBTI-H, PBTI-F and PBTI-Cl) to address this issue. Relative to the fused-ring based counterparts, these three PSMAs exhibit much higher figure-of-merit value. Additionally, a power-conversion efficiency of 8.80% is achieved in the PBTI-Cl-based all-PSC. The results offer an attractive approach to design low-cost PSMAs for efficient all-PSCs. [ABSTRACT FROM AUTHOR]

PageRank can be viewed as a hyperlink-based method for estimating the importance of nodes in a network, and has attracted a lot of attention from researchers. In this paper, we first propose an extrapolation procedure for PageRank vector estimation based on the linear combination of the Ritz values computed from the Hessenberg process and eigenvectors from the classical power method. In order to improve the convergence rate of the PageRank computations, the extrapolation procedure is introduced into the Hessenberg-type algorithm by Gu et al. (Numer. Algorithms, 89(4): 1845–1863, 2022), then a new algorithm is derived and named Hessenberg-extrapolation algorithm whose convergence and construction are investigated in detail. In addition, we further analyze the convergence of the Hessenberg-type algorithm and discuss the relationship between the approximate vectors of the Hessenberg-type algorithm and the Arnoldi-type algorithm. Numerical experiments on several examples demonstrate that our presented algorithm has great potential in PageRank approximation. [ABSTRACT FROM AUTHOR]

The extended Fisher–Kolmogorov (EFK) equation has been used to describe some phenomena in physical, material and biological systems. In this paper, we propose a full-rank splitting scheme and a rank-adaptive splitting approach for this equation. We first use a finite difference method to approximate the space derivatives. Then, the resulting semi-discrete system is split into two stiff linear parts and a nonstiff nonlinear part. This leads to our full-rank splitting scheme. The convergence of the proposed scheme is proved rigorously. Based on the frame of the full-rank splitting scheme, we design a rank-adaptive splitting approach for obtaining a low-rank solution of the EFK equation. Numerical examples show that our methods are robust and accurate. They can also preserve the energy dissipation. • The EFK equation is split into three subproblems, then a full-rank splitting scheme is established. The convergence of this scheme is analyzed. • A rank-adaptive low-rank approach is proposed for the EFK equation. To the best of our knowledge, this is new in the literature for the equation. • Numerical examples show that our methods are robust and accurate. They can also preserve energy dissipation. [ABSTRACT FROM AUTHOR]

Tensile strength, porosity and microstructure evolution of ultrasonic bonding for BVR2.5 Cu cables at different welding energies were investigated. By X-ray computed tomography and modification of the Johnson-Cook model, the predictive model of porosity was developed for the first time to assess joint strength. When the porosity was lower than 19%, the joint formed a good bond and reached the tensile strength of 585.7 ± 17.9 N. The maximum joint tensile strength was achieved at about 10% porosity. The Cu grains at the interface underwent plastic deformation, discontinuous dynamic recrystallisation and dynamic recovery to form a good bond. Interfacial grains are refined by ultrasonic vibrations, but the reduction of the porosity is the critical factor in improving joint strength. [ABSTRACT FROM AUTHOR]

PageRank is a widespread model for analysing the relative relevance of nodes within large graphs arising in several applications. In the current paper, we present a cost-effective Hessenberg-type method built upon the Hessenberg process for the solution of difficult PageRank problems. The new method is very competitive with other popular algorithms in this field, such as Arnoldi-type methods, especially when the damping factor is close to 1 and the dimension of the search subspace is large. The convergence and the complexity of the proposed algorithm are investigated. Numerical experiments are reported to show the efficiency of the new solver for practical PageRank computations. [ABSTRACT FROM AUTHOR]

In this note, we revisit the result of the Toeplitz matrix inversion formula proposed by Lv and Huang (2007), then we give a new structured perturbation analysis, which is useful for testing the stability of practical algorithms. It has been shown that our new upper bound is much sharper than the one they have given, especially when the size of the Toeplitz matrix is very large. Numerical experiments illustrate the effectiveness of our theoretical results. [ABSTRACT FROM AUTHOR]

In this paper, for variable coefficient Riesz fractional diffusion equations in one and two dimensions, we first design a second-order implicit difference scheme by using the Crank-Nicolson method and a fractional centered difference formula for time and space variables, respectively. With the compact operator acting on, a novel fourth-order finite difference scheme is subsequently constructed. Solvability, stability and convergence of these schemes are theoretically analyzed. For these discretized linear systems, the fast implementation with preconditioners based on sine transform is proposed, which has the computational complexity of O (n log ⁡ n) per iteration and the memory requirement of O (n) , where n represents the total number of the spatial grid nodes. Finally, numerical experiments are performed to illustrate the preciseness and effectiveness of these new techniques. • Two numerical schemes can be proved of stability and high convergence order in space. • The rarely investigated preconditioners can remain the total computational complexity as O (n log ⁡ n). • Our proposed schemes can be flexibly extended to the multi-dimensional problems. [ABSTRACT FROM AUTHOR]

Background: The present study aims to investigate the preliminary mechanism underlying the peritoneal metastasis of gastric cancer cells. Methods: Exosomes from GC9811 cells (Con-Exo) and from GC9811-P cells (PM-Exo) were extracted by ultracentrifugation, which were identified with transmission electron microscopy (TEM) and nanoparticle trafficking analysis, as well as the expression of CD9, CD63, and CD81 detected by Western blot assay. α-SMA expression was determined by immunofluorescence assay and Western blot assay. The levels of Snail1, E-cadherin, and Actin-related protein 3 (ACTR3) were evaluated by Western blot assay. MiRNA array was performed on exosomes to screen the differentially expressed miRNAs. The expressions of miRNAs, SMAD2, CDK4, and ACTR3 were determined by QRT-PCR. The delivery of miR-486-5p was confirmed by laser confocal detection. Results: Firstly, TEM, nanoparticle trafficking analysis, and Western blot assays were used to confirm the successful extraction of Con-Exo and PM-Exo. The incubation of Con-Exo and PM-Exo could decrease E-cadherin expression and increase of α-SMA respectively in HMrSV5 cells, with the increased proportion of fusiform cells. More significant changes were observed in PM-Exo-treated HMrSV5 cells. Secondary, compared to Con-Exo, miR-486-5p and miR-132-3p were found downregulated, and miR-132-5p was found upregulated in PM-Exo. The transfection of miR-486-5p and miR-132-3p was observed to suppress EMT, and the transfection of miR-132-3p was observed to induce EMT. Laser confocal detection confirmed the delivery of miR-486-5p from gastric cancer cells to HMrSV5 cells through exosomes. Lastly, the expression of Mothers against decapentaplegic homolog 2 (SMAD2), cyclin-dependent kinase 4 (CDK4), and ACTR3 was found to be downregulated via miR-486-5p. Conclusion: Decreased delivery of miR-486-5p via exosomes might be responsible for the peritoneal metastasis of gastric cancer cells by promoting epithelial-mesenchymal transition progress. [ABSTRACT FROM AUTHOR]

Background: The present study aims to investigate the preliminary mechanism underlying the peritoneal metastasis of gastric cancer cells. Methods: Exosomes from GC9811 cells (Con-Exo) and from GC9811-P cells (PM-Exo) were extracted by ultracentrifugation, which were identified with transmission electron microscopy (TEM) and nanoparticle trafficking analysis, as well as the expression of CD9, CD63, and CD81 detected by Western blot assay. α-SMA expression was determined by immunofluorescence assay and Western blot assay. The levels of Snail1, E-cadherin, and Actin-related protein 3 (ACTR3) were evaluated by Western blot assay. MiRNA array was performed on exosomes to screen the differentially expressed miRNAs. The expressions of miRNAs, SMAD2, CDK4, and ACTR3 were determined by QRT-PCR. The delivery of miR-486-5p was confirmed by laser confocal detection. Results: Firstly, TEM, nanoparticle trafficking analysis, and Western blot assays were used to confirm the successful extraction of Con-Exo and PM-Exo. The incubation of Con-Exo and PM-Exo could decrease E-cadherin expression and increase of α-SMA respectively in HMrSV5 cells, with the increased proportion of fusiform cells. More significant changes were observed in PM-Exo-treated HMrSV5 cells. Secondary, compared to Con-Exo, miR-486-5p and miR-132-3p were found downregulated, and miR-132-5p was found upregulated in PM-Exo. The transfection of miR-486-5p and miR-132-3p was observed to suppress EMT, and the transfection of miR-132-3p was observed to induce EMT. Laser confocal detection confirmed the delivery of miR-486-5p from gastric cancer cells to HMrSV5 cells through exosomes. Lastly, the expression of Mothers against decapentaplegic homolog 2 (SMAD2), cyclin-dependent kinase 4 (CDK4), and ACTR3 was found to be downregulated via miR-486-5p. Conclusion: Decreased delivery of miR-486-5p via exosomes might be responsible for the peritoneal metastasis of gastric cancer cells by promoting epithelial-mesenchymal transition progress. [ABSTRACT FROM AUTHOR]

This article investigates $H_{\infty }$ synchronization of delayed neural networks under a receding horizon scheme, where two types of interval time-varying delays are considered according to whether the lower bound of the delay derivative is known or not. Note that a receding horizon synchronization law can be regarded as an optimization solution at each timeslot to a minimaxization problem related closely with a certain cost functional. In this article, two cost functionals with some delay-dependent matrices are introduced, respectively, for the two types of time delays. In order to obtain less conservative conditions, a novel inequality on quadratic polynomial functions is established, which includes some existing ones as its special cases. Based on the novel inequality, two sufficient conditions are derived to design the terminal weighting matrices of the cost functionals such that the resulting synchronization error system can be stabilized with a prescribed infinite horizon $H_{\infty }$ performance level. Finally, three numerical examples are used to demonstrate the validity of the proposed results. [ABSTRACT FROM AUTHOR]

X-ray emission from the collisions of 3 MeV Ar11 + ions with V, Fe, Co, Ni, Cu, and Zn is investigated. Both the x-rays of the target atom and projectile are observed simultaneously. The x-ray yield is extracted from the original count. The inner-shell ionization cross section is estimated by the binary encounter approximation model and compared with the experimental result. The remarkable result is that the Ar K-shell x-ray yield is diminished with the target atomic number increasing, which is completely opposite to the theoretical calculation. That is interpreted by the competitive consumption of the energy loss for the ionization of inner-shell electrons between the projectile and target atom. [ABSTRACT FROM AUTHOR]

Understanding molecular motion in terms of molecular structure is an important issue for microscopic understanding of the nature of transport properties and glass transition, and for design of structured materials to meet specific demands in various applications. Herein, a novel molecular mechanism is proposed to connect macroscopic motion in ionic liquids with molecular structure via conformational conversions of the constituent ions or of the cation-anion pairs. New equations for description of relaxation time, diffusion coefficient, molar conductivity, and viscosity of ionic liquids are established. The equation parameters, which were determined from the temperature dependent heat capacities, self-diffusion coefficients, molar conductivities, and viscosities of typical ionic liquids, were used to produce predictions for the corresponding properties of other ionic liquids and for the glass transition temperatures of representative ionic liquids. All predictions are in nice agreements with the experimental results. [ABSTRACT FROM AUTHOR]

In view of the small sample size of combat ammunition trial data and the difficulty of forecasting the demand for combat ammunition, a Bayesian inference method based on multinomial distribution is proposed. Firstly, considering the different damage grades of ammunition hitting targets, the damage results are approximated as multinomial distribution, and a Bayesian inference model of ammunition demand based on multinomial distribution is established, which provides a theoretical basis for forecasting the ammunition demand of multigrade damage under the condition of small samples. Secondly, the conjugate Dirichlet distribution of multinomial distribution is selected as a prior distribution, and Dempster–Shafer evidence theory (D-S theory) is introduced to fuse multisource previous information. Bayesian inference is made through the Markov chain Monte Carlo method based on Gibbs sampling, and ammunition demand at different damage grades is obtained by referring to cumulative damage probability. The study result shows that the Bayesian inference method based on multinomial distribution is highly maneuverable and can be used to predict ammunition demand of different damage grades under the condition of small samples. [ABSTRACT FROM AUTHOR]

Objective: To explore effects of repetitive transcranial magnetic stimulation (rTMS) combined with transcranial direct current stimulation (tDCS) on motor function and cortex excitability in subacute stroke patients. Design: Randomized controlled trial. Setting: Inpatient hospitals. Subjects: Sixty-five participants were randomly assigned to four groups: sham, 1Hz rTMS, cathodic tDCS combined with 1Hz rTMS (tDCS-/rTMS-) and anodic tDCS combined with 1Hz rTMS (tDCS+/rTMS-). Interventions: Four interventions were used, including sham, 1Hz rTMS, and cathodal or anodal tDCS, followed by 1Hz rTMS over contralesional motor cortex, which continued for four weeks. Main measures: Outcome measures were motor function and cortical excitability, evaluated by Fugl-Meyer Assessment, National Institutes of Health Stroke Scale and Barthel Index, resting Motion Threshold, Motor Evoked Potentials and Central Motor Conduction Time, assessed at baseline, four weeks and eight weeks. Results: At four weeks after interventions, Fugl-Meyer Assessment lower limb change score in tDCS+/rTMS- group was significantly larger than other three groups (P < 0.001). There were significant differences in bilateral Motor Evoked Potentials changes between tDCS+/rTMS- group and sham group (P < 0.05). At eight weeks, compared to other groups, National Institutes of Health Stroke Scale (P = 0.003), Barthel Index (P = 0.002), FMA lower limb score (P < 0.001), and bilateral resting Motion Threshold, Motor Evoked Potentials (P < 0.05) showed significant changes in tDCS+/rTMS- group. Furthermore, Fugl-Meyer Assessment lower limb change score was associated with increased ipsilesional Motor Evoked Potentials (r = 0.703 P < 0.001) in tDCS+/rTMS- group. Conclusion: 1Hz rTMS combined with anode tDCS stimulation protocol could be a preferable rehabilitative strategy for motor recovery in subacute stroke patients. [ABSTRACT FROM AUTHOR]

Ligand‐protected heterometallic nanoclusters in contrast to homo‐metal counterparts show more broad applications due to the synergistic effect of hetero‐metals but their controllable syntheses remain a challenge. Among heterometallic nanoclusters, monovalent Ag‐Cu compounds are rarely explored due to much difference of Ag(I) and Cu(I) such as atom radius, coordination habits, and redox potential. Encouraged by copper‐catalyzed alkyne‐azide cycloaddition (CuAAC) reaction, comproportionation reaction of Cu(II)X2 and Cu(0) in the presence of (PhC≡CAg)n complex and molybdate generated a core‐shell peanut‐shaped 66‐nuclear Ag(I)‐Cu(I) heterometallic nanocluster, [(Mo4O16)2@Cu12Ag54(PhC≡C)50] (referred to as Ag54Cu12). The structure and composition of Ag‐Cu heterometallic nanocluster are fully characterized. X‐ray single crystal diffraction reveals that Ag54Cu12 has a peanut‐shaped silver(I)/copper(I) heterometallic nanocage protected by fifty phenylacetylene ligands in µ3–modes and encapsulated two mutually twisted tetramolybdates. Heterometallic nanocage contains a 54‐Ag‐atom outer ellipsoid silver cage decorated by 12 copper inside wall. Nanosized Ag54Cu12 is a n‐type narrow‐band‐gap semiconductor with a good photocurrent response. Preliminary experiments demonstrates that Ag54Cu12 itself and activated carbon supported Ag54Cu12/C are effective catalysts for 1,3‐dipole cycloaddition between alkynes and azides at ambient conditions. The work provides not only a new synthetic route toward Ag(I)‐Cu(I) nanoclusters but also an important heterometallic intermediate in CuAAC catalytic reaction. [ABSTRACT FROM AUTHOR]

Oxygen transport is central to many properties of oxides such as stoichiometric changes, phase transformation, and ionic conductivity. In this paper, we report a mechanism for oxygen transport in uranium dioxide (UO2) in which the kinetics is mediated by defect clustering dynamics. In particular, the kinetic Monte Carlo method has been used to investigate the kinetics of oxygen transport in UO2 under the condition of creation and annihilation of oxygen vacancies and interstitials as well as oxygen interstitial clustering, with variable off-stoichiometry and temperature conditions. It is found that in hypo-stoichiometric U O2-x, oxygen transport is well described by the vacancy diffusion mechanism while in hyper-stoichiometric UO2+x, oxygen interstitial cluster diffusion contributes significantly to oxygen transport kinetics, particularly at high temperatures and high off-stoichiometry levels. It is also found that di-interstitial clusters and single interstitials play dominant roles in oxygen diffusion while other larger clusters have negligible contributions. However, the formation, coalescence, and dissociation of these larger clusters indirectly affects the overall oxygen diffusion due to their interactions with mono and di-interstitials, thus providing an explanation of the experimental observation of saturation or even drop of oxygen diffusivity at high off-stoichiometry. [ABSTRACT FROM AUTHOR]

In view of the small sample size of combat ammunition trial data and the difficulty of forecasting the demand for combat ammunition, a Bayesian inference method based on multinomial distribution is proposed. Firstly, considering the different damage grades of ammunition hitting targets, the damage results are approximated as multinomial distribution, and a Bayesian inference model of ammunition demand based on multinomial distribution is established, which provides a theoretical basis for forecasting the ammunition demand of multigrade damage under the condition of small samples. Secondly, the conjugate Dirichlet distribution of multinomial distribution is selected as a prior distribution, and Dempster–Shafer evidence theory (D-S theory) is introduced to fuse multisource previous information. Bayesian inference is made through the Markov chain Monte Carlo method based on Gibbs sampling, and ammunition demand at different damage grades is obtained by referring to cumulative damage probability. The study result shows that the Bayesian inference method based on multinomial distribution is highly maneuverable and can be used to predict ammunition demand of different damage grades under the condition of small samples. [ABSTRACT FROM AUTHOR]

There is a close relationship between the liver and heart based on "zang-xiang theory," "five-element theory," and "five-zang/five-viscus/five-organ correlation theory" in the theoretical system of Traditional Chinese Medicine (TCM). Moreover, with the development of molecular biology, genetics, immunology, and others, the Modern Medicine indicates the existence of the essential interorgan communication between the liver and heart (the heart and liver). Anatomically and physiologically, the liver and heart are connected with each other primarily via "blood circulation." Pathologically, liver diseases can affect the heart; for example, patients with end-stage liver disease (liver failure/cirrhosis) may develop into "cirrhotic cardiomyopathy," and nonalcoholic fatty liver disease (NAFLD) may promote the development of cardiovascular diseases via multiple molecular mechanisms. In contrast, heart diseases can affect the liver, heart failure may lead to cardiogenic hypoxic hepatitis and cardiac cirrhosis, and atrial fibrillation (AF) markedly alters the hepatic gene expression profile and induces AF-related hypercoagulation. The heart can also influence liver metabolism via certain nonsecretory cardiac gene-mediated multiple signals. Moreover, organokines are essential mediators of organ crosstalk, e.g., cardiomyokines link the heart to the liver, while hepatokines link the liver to the heart. Therefore, both TCM and Western Medicine, and both the basic research studies and the clinical practices, all indicate that there exist essential "heart-liver axes" and "liver-heart axes." To investigate the organ interactions between the liver and heart (the heart and liver) will help us broaden and deepen our understanding of the pathogenesis of both liver and heart diseases, thus improving the strategies of prevention and treatment in the future. [ABSTRACT FROM AUTHOR]

In this article, we first propose an unconditionally stable implicit difference scheme for solving generalized time–space fractional diffusion equations (GTSFDEs) with variable coefficients. The numerical scheme utilizes the L1‐type formula for the generalized Caputo fractional derivative in time discretization and the second‐order weighted and shifted Grünwald difference (WSGD) formula in spatial discretization, respectively. Theoretical results and numerical tests are conducted to verify the (2 − γ)‐order and 2‐order of temporal and spatial convergence with γ ∈ (0, 1) the order of Caputo fractional derivative, respectively. The fast sum‐of‐exponential approximation of the generalized Caputo fractional derivative and Toeplitz‐like coefficient matrices are also developed to accelerate the proposed implicit difference scheme. Numerical experiments show the effectiveness of the proposed numerical scheme and its good potential for large‐scale simulation of GTSFDEs. [ABSTRACT FROM AUTHOR]

In recent years, more users tend to use data mining as a service (DMaaS) provided by cloud service providers. However, while enjoying the convenient pay-per-use mode and powerful capacity of cloud computing, users are also threatened by the potential risk of privacy leakage. In this paper, we aim to efficiently perform privacy-preserving DMaaS, and focus on frequent itemset mining over encrypted database in outsourced cloud environment. Existing work apply different encryption methods to design various privacy-preserving mining solutions. Nevertheless, these approaches either cannot provide sufficient security requirements, or introduce heavy computation costs. Some of them also need users staying on-line to execute computations, which are not practical in real-world applications. In this paper, we propose a novel efficient privacy-preserving frequent itemset query (PPFIQ) scheme using two homomorphic encryptions and ciphertext packing technique. The proposed scheme protects transaction database with semantic security, preserves mining privacy and resists frequency analysis attacks. Meanwhile, efficiency is guaranteed by inherent parallel computations for packed plaintexts and users could stay off-line during the mining process. We provide formal security analysis and evaluate the performance of our scheme with extensive experiments. The experiment results demonstrate that the proposed scheme can be efficiently implemented on large databases. [ABSTRACT FROM AUTHOR]

The infinity norm bounds for the inverse of Nekrasov matrices play an important role in scientific computing. We in this paper propose a triangulation-based approach that can easily be implemented to seek sharper infinity norm bounds for the inverse of Nekrasov matrices. With the help of such sharper bounds, new error estimates for the linear complementarity problem of Nekrasov matrices are presented, and a new infinity norm estimate of the iterative matrix of parallel-in-time methods for an all-at-once system from Volterra partial integral-differential problems is given. Finally, these new bounds are compared with other state-of-the-art results so that the effectiveness of our proposed results is verified. [ABSTRACT FROM AUTHOR]

Biogenic amines are naturally present as hazardous, low-molecular organic basic compounds in various foods. Lactic acid bacteria show excellent potential to prevent biogenic amines accumulation. In this study, the amine-reducing mechanism of Lactiplantibacillus planatraum JB1, a strain isolated from fermented sausages, was explored according to its genome, and its ability to degrade biogenic amines was also evaluated in culture medium and dry sausage. The results showed that L. plantarum JB1 possessed a myriad of desirable properties, including tolerance to harsh environments and safety for assessment in vitro. Its genome contained genes encoding transport proteins and multicopper oxidase, which may be involved in biogenic amine degradation. In PBS and MRS medium, L. plantarum JB1 could degrade eight biogenic amines with high degradation rates for tyramine and putrescine. By inoculating sausages with L. plantarum JB1, the total content of biogenic amine was decreased by 32.84% after preparation and 32.07% after storage. Due to its good adaptability, security and amine-reducing capacity, L. plantarum JB1 could be considered a starter culture to ensure the safety of meat products. • L. plantarum JB1 showed good adaptability, security and amine-reducing potential. • Amine-reducing genes related to biogenic amine transport and multicopper oxidase. • L. plantarum JB1 degraded eight BAs, especially for tyramine. • L. plantarum JB1 could reduce BAs both in food processing and storage. [ABSTRACT FROM AUTHOR]

In this paper, we develop two fast implicit difference schemes for solving a class of variable‐coefficient time–space fractional diffusion equations with integral fractional Laplacian (IFL). The proposed schemes utilize the graded L1 formula for the Caputo fractional derivative and a special finite difference discretization for IFL, where the graded mesh can capture the model problem with a weak singularity at initial time. The stability and convergence are rigorously proved via the M‐matrix analysis, which is from the spatial discretized matrix of IFL. Moreover, the proposed schemes use the fast sum‐of‐exponential approximation and Toeplitz matrix algorithms to reduce the computational cost for the nonlocal property of time and space fractional derivatives, respectively. The fast schemes greatly reduce the computational work of solving the discretized linear systems from O(MN3+M2N) by a direct solver to O(MN(logN+Nexp)) per preconditioned Krylov subspace iteration and a memory requirement from 𝒪(MN2) to 𝒪(NNexp), where N and (Nexp ≪) M are the number of spatial and temporal grid nodes, respectively. The spectrum of preconditioned matrix is also given for ensuring the acceleration benefit of circulant preconditioners. Finally, numerical results are presented to show the utility of the proposed methods. [ABSTRACT FROM AUTHOR]

Significance: Selenenyl sulfides (RSeSRs) and thioseleninic acids (RSeSHs) are the monoselenium (Se) analogs of disulfides and persulfides that contain Se-S bonds. These bonds are found in several antioxidant-regenerating enzymes as derivatives of selenocysteine, making them an important player in redox biology as it pertains to sulfur redox regulation. Recent Advances: Mechanistic studies of redox-regulating selenoenzymes such as thioredoxin reductase and glutathione peroxidase suggest crucial Se-S bonds in the active sites. Peptide models and small-molecule mimics of these active sites have been prepared to study their fundamental chemistry. These advances help pave the road to better understand the functions of the Se-S bond in the body. Critical Issues: The Se-S bond is unstable at atmospheric temperatures and pressures. Therefore, studying their properties proposes a major challenge. Currently, there are no trapping reagents specific to RSeSRs or RSeSHs, making their presence, identity, and fates in biological environments difficult to track. Future Directions: Further understanding of the fundamental chemistry/biochemistry of RSeSRs and RSeSHs is needed to understand what their intracellular targets are and to what extent they impact signaling. Besides antioxidant regeneration and peroxide radical reduction, the roles of RSeSR and RSeSHs in other systems need to be further explored. [ABSTRACT FROM AUTHOR]

Shape sensing refers to the deformation reconstruction of structures using measured surface strain. However, there is currently a lack of research on the shape sensing of large deformations, especially for beam structures. To address this issue, this paper proposes a new method called the rotation angle approximation (RAA) for reconstructing large deformations of beam structures. This method utilizes theoretical and actual curvatures to create a least-squares error functional. By minimizing this functional, the rotation angles of the corresponding beam can be obtained, avoiding the accumulation of errors that occurs when using traditional computation methods. The deformed shapes can be predicted utilizing the boundary conditions and the rotation angles along the beam. This method can reconstruct the large deformation of a beam without requiring prior knowledge about the material properties or external loads. The accuracy and effectiveness of this method were validated through numerical simulations and experiments. The results indicate that this method can accurately predict the different deformations of a beam induced by various loading conditions. [ABSTRACT FROM AUTHOR]

A 74-year-old woman with left main and three-vessel coronary artery disease was scheduled for off-pump coronary artery bypass grafting and developed acute severe cholecystitis preoperatively. Percutaneous gallbladder drainage was placed to achieve gallbladder decompression and infection control. Two weeks later, CABG and laparoscopic cholecystectomy were successfully performed at the same time. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the well-posedness of the real fractional Ginzburg–Landau equation in several different function spaces, which have been used to deal with the Burgers' equation, the semilinear heat equation, the Navier–Stokes equations, etc. The long time asymptotic behavior of the nonnegative global solutions is also studied in details. [ABSTRACT FROM AUTHOR]

Hexahydro-1,3,5-triazines are often used as formaldimine precursors. The recent success of Sun et al. (Angew. Chem. Int. Ed., 2016, 55 , 11867) in achieving gold-catalyzed [4 + 1]/[4 + 3] annulations of hexahydro-1,3,5-triazines with diazo esters, in which the hexahydro-1,3,5-triazine is directly used as the 1,4-dipole in the annulation, represents a breakthrough in mechanistic studies. In the present work, density functional theory (DFT) calculations were used for detailed investigation of possible catalytic mechanisms. The proposed catalytic cycle involves five major stages: dinitrogen elimination to form a gold–carbene intermediate; diazoacetate–hexahydro-1,3,5-triazine C–C coupling to give an ammonium ylide; ring opening of the hexahydro-1,3,5-triazine via C–N single-bond cleavage; a second C–N single-bond cleavage; and C–C-bond-forming reductive elimination. The regioselectivities of the cycloaddition of hexahydro-1,3,5-triazines with enol diazoacetates differ from those of cycloadditions with vinyl diazoacetates. The calculations also clarified the origins of the substrate-controlled regioselectivity. Image 1 • Origin of substrate-controlled regioselectivity was clarified. • Novel reaction mechanism for the hexahydro-1,3,5-triazine was exploited. • Second gold is important in facilitating the reaction. [ABSTRACT FROM AUTHOR]

In this paper, two efficient iterative algorithms based on the Simpler GMRES method are proposed for solving shifted linear systems. To make full use of the shifted structure, the proposed algorithms utilizing the deflated restarting strategy and flexible preconditioning can significantly reduce the number of matrix–vector products and the elapsed CPU time. Numerical experiments are reported to illustrate the performance and effectiveness of the proposed algorithms. [ABSTRACT FROM AUTHOR]

Aims: To estimate the effects of the sodium-glucose cotransporter 2 inhibitor (SGLT2i) on proteinuria and oxidative stress expression in type 2 diabetes patients. Materials and methods: 68 patients with type 2 diabetes mellitus (T2DM) were divided into three groups according urinary albumin-to-creatinine ratio (UACR), including T2DM with non-albuminuria group (UACR < 30 mg/g), T2DM with microalbuminuria group (30 ≤ UACR ≤ 300 mg/g), T2DM with macroalbuminuria group (UACR>300 mg/g). They all received SGLT2 inhibitors (SGLT2i) treatment for 12 weeks. The expression of advanced glycation end products (AGEs) in plasma and 8-hydroxy-2-deoxyguanosine (8-OHdG) in urine were measured as indications of oxidative stress. The 24-hour urine samples were collected to measure the concentration of proteinuria and 8-OHdG before and after 12 weeks SGLT2i treatment. Plasma renin activity (PRA), angiotensin II (Ang II) and Aldosterone (ALD) were measured to evaluate renin angiotensin aldosterone system (RASS) levels. Results: After 12 weeks SGLT2 inhibitors treatment, the median values of 24-hour proteinuria decreased in macroalbuminuria compared to baseline (970 vs. 821 mg/d, P = 0.006). The median values of AGEs and 8-OHdG decreased in microalbuminuria and macroalbuminuria groups when compared to baseline, AGEs (777 vs. 136 ug/ml, P = 0.003) and (755 vs. 210 ug/ml, P = 0.001), 8-OHdG (8.00 vs. 1.88 ng/ml, P = 0.001) and (11.18 vs. 1.90 ng/ml, P < 0.001), respectively. Partial correlations showed that 8-OHdG were relevant to the baseline 24-h proteinuria (r = 0.389, p = 0.001), the reduction of OHdG (Δ8-OHdG) were positively correlated with the decrease of 24-h proteinuria (Δ24-h proteinuria) after 12 weeks of SGLT2i treatment (r = 0.283, P = 0.031). There was no significant correlation between 24-h proteinuria and AGEs in baseline (r = −0.059, p = 0.640) as well as between ΔAGEs and Δ24-h proteinuria (r = 0.022, p = 0.872) after12 weeks of SGLT2i treatment in T2DM patients. Conclusions: SGLT2i may reduce proteinuria in diabetic nephropathy patients, potentially by inhibiting renal oxidative stress, but not through the AGEs pathway and does not induce RAAS activation. Trial registration: This clinical trial was registered on 15/10/2019, in ClinicalTrials.gov, and the registry number is NCT04127084. [ABSTRACT FROM AUTHOR]

We present a simple approach to calculate the solid-liquid interfacial free energy. This new method is based on the classical nucleation theory. Using the molecular dynamics simulation, we employ spherical crystal nuclei embedded in the supercooled liquids to create an ideal model of a homogeneous nucleation. The interfacial free energy is extracted by fitting the relation between the critical nucleus size and the reciprocal of the critical undercooling temperature. The orientationally averaged interfacial free energy is found to be 0.302±0.002 (in standard LJ unit). The temperature dependence of the interfacial free energy is also obtained in this work. We find that the interfacial free energy increases slightly with increasing temperature. The positive temperature coefficient of the interfacial free energy is in qualitative agreement with Spaepen’s analysis [Solid State Phys. 47, FS181 (1994)] and Turnbull’s empirical estimation [J. Appl. Phys. 21, 1022 (1950)]. [ABSTRACT FROM AUTHOR]