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In this paper, we introduce multiple skew-orthogonal polynomials and investigate their connections with classical integrable systems. By using Pfaffian techniques, we show that multiple skew-orthogonal polynomials can be expressed by multi-component Pfaffian tau-functions upon appropriate deformations. Moreover, a two-component Pfaff lattice hierarchy, which is equivalent to the Pfaff–Toda hierarchy studied by Takasaki, is obtained by considering the recurrence relations and Cauchy transforms of multiple skew-orthogonal polynomials. [ABSTRACT FROM AUTHOR]

Starting with a skew-symmetric inner product over an elliptic curve, we propose the concept of elliptic skew-orthogonal polynomials. Inspired by the Landau–Lifshitz hierarchy and its corresponding time evolutions, we obtain the recurrence relation and the |$\tau $| -function representation for such a novel class of skew-orthogonal polynomials. Furthermore, a bilinear integral identity is derived through the so-called Cauchy–Stieljes transformation, from which we successfully establish the connection between the elliptic skew-orthogonal polynomials and an elliptic extension of the Pfaff lattice hierarchy. [ABSTRACT FROM AUTHOR]

Amongst the many additive manufacturing (AM) techniques, directed energy deposition (DED) is a prominent one, which can also be used for the repair of damaged components. In this paper, we provide an overview on it, with emphasis on the typical microstructures of DED alloys and discuss the processing-microstructure-mechanical property correlations. Comparison is made with those manufactured using the conventional techniques and those obtained with laser beam powder bed fusion (LB-PBF). The characteristic solidification rates and thermal histories in DED result in distinct micro- and meso-structural features and mechanical performance, which are succinctly summarized. The potential of DED for manufacturing graded materials and for component repair is elaborated while highlighting the key-associated challenges and possible solutions. Modelling and simulation studies that facilitate an in-depth understanding of the DED technique are summarized. Finally, some critical issues and research directions that would help develop DED further and extend its application potential are identified. [ABSTRACT FROM AUTHOR]

A framework to study the eigenvalue probability density function for products of unitary random matrices with an invariance property is developed. This involves isolating a class of invariant unitary matrices, to be referred to as cyclic Pólya ensembles, and examining their properties with respect to the spherical transform on U (N) . Included in the cyclic Pólya ensemble class are Haar invariant unitary matrices, the circular Jacobi ensemble, known in relation to the Fisher-Hartwig singularity in the theory of Toeplitz determinants, as well as the heat kernel for Brownian motion on the unitary group. We define cyclic Pólya frequency functions and show their relation to the cyclic Pólya ensembles, and give a uniqueness statement for the corresponding weights. The natural appearance of bilateral hypergeometric series is highlighted, with this special function playing the role of the Meijer G-function in the transform theory of unitary invariant product of positive definite matrices. We construct a family of functions forming bi-orthonormal pairs which underly the correlation kernel of the corresponding determinantal point processes, and furthermore obtain an integral formula for the correlation kernel involving just two of these functions. [ABSTRACT FROM AUTHOR]

This paper focuses on different reductions of the two-dimensional (2d)-Toda hierarchy. Symmetric and skew-symmetric moment matrices are first considered, resulting in differential relations between symmetric/skew-symmetric tau functions and 2d-Toda’s tau functions, respectively. Furthermore, motivated by the Cauchy two-matrix model and Bures ensemble from random matrix theory, we study the rank-one shift condition in the symmetric case and rank-two shift condition in the skew-symmetric case, from which the C-Toda and B-Toda hierarchies are determined, together with their special Lax matrices and integrable structures. [ABSTRACT FROM AUTHOR]

In this paper, we plan to show an eigenvalue algorithm for block Hessenberg matrices by using the idea of non-commutative integrable systems and matrix-valued orthogonal polynomials. We introduce adjacent families of matrix-valued θ\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\theta $$\end{document}-deformed bi-orthogonal polynomials, and derive corresponding discrete non-commutative hungry Toda lattice from discrete spectral transformations for polynomials. It is shown that this discrete system can be used as a pre-precessing algorithm for block Hessenberg matrices. Besides, some convergence analysis and numerical examples of this algorithm are presented. [ABSTRACT FROM AUTHOR]

To investigate the effects of hydrogen (H) on the mechanical properties of 316L austenitic stainless steel (316L) additively manufactured using laser-powder bed fusion (L-PBF), tensile, nanoindentation, and micropillar compression tests were performed on samples in both the as-built (AB) and H-charged (HC) conditions. Microstructural characterization revealed that the electrochemical H charging exerted marginal effects on grains, phases, and overall dislocation densities of L-PBF 316L. However, the dislocation networks inherent to L-PBF 316L appear to disentangle upon H charging and are distributed more homogeneously through the matrix. Mechanical test results showed that H charging results in a marginal reduction in hardness and strength, indicating H-induced softening, possibly due to the elastic shielding effects of H that weaken the interactions between dislocations. The elastic shielding effect and the enhanced slip planarity, facilitate the H accumulation along slip bands and twins, promote H-enhanced localized plasticity, resulting cracking when a critical H concentration is reached. This, in turn, aids in H embrittlement mechanism that results in a significant loss in ductility upon H charging. A detailed discussion of all these micromechanisms is presented. [Display omitted] [ABSTRACT FROM AUTHOR]

The theory of Pólya ensembles of positive definite random matrices provides structural formulas for the corresponding biorthogonal pair, and correlation kernel, which are well suited to computing the hard edge large N asymptotics. Such an analysis is carried out for products of Laguerre ensembles, the Laguerre Muttalib–Borodin ensemble, and products of Laguerre ensembles and their inverses. The latter includes, as a special case, the Jacobi unitary ensemble. In each case, the hard edge scaled kernel permits an expansion in powers of 1/N, with the leading term given in a structured form involving the hard-edge scaling of the biorthogonal pair. The Laguerre and Jacobi ensembles have the special feature that their hard edge scaled kernel – the Bessel kernel – is symmetric and this leads to there being a choice of hard edge scaling variables for which the rate of convergence of the correlation functions is O (1 / N 2). [ABSTRACT FROM AUTHOR]

Transcription factors (TFs) play an important role in tumors. We integrated and analyzed 13 GPL570 platform gastric cancer (GC) microarrays, identified 10 independent prognostic TFs, and constructed a GC prognostic model. Using GSE26942 as the verification set, the Kaplan-Meier curve showed that the signature distinguish the survival rate of GC patients (P < 0.01), and the AUC values are 0.746 and 0.630, respectively. Compared with the clinicopathological characteristics, the signature is an independent prognostic factor (P < 0.05). A nomogram was established based on the model, and the five-year calibration curve verified that the prediction of the nomogram was almost consistent with the actual survival rate, C-index of 0.747 indicated a moderate prognostic ability. The analysis of target genes of 10 TFs showed that they are closely related to the progression of GC. External database and rt-PCR showed that the RNA and protein expression of TFs are consistent with our analysis. • Integrating the GPL570 platform 13 gastric cancer micro-arrays to get 1027 samples. • Transcription factors differentially expressed in gastric cancer were identified. • The prognostic-related TFs were identified and a prognostic model was constructed. • The target genes of hub TFs were predicted and the molecular mechanism was analyzed. • The critical TFs have been verified by external databases and experiments. [ABSTRACT FROM AUTHOR]

A |$\theta $| -deformation of the Laguerre weighted Cauchy two-matrix model, and the Bures ensemble, is introduced. Such a deformation is familiar from the Muttalib–Borodin ensemble. The |$\theta $| -deformed Cauchy–Laguerre two-matrix model is a two-component determinantal point process. It is shown that the correlation kernel, and its hard edge scaled limit, can be written in terms of particular Fox H-functions, generalising the Meijer G-function class known from the study of the case |$\theta = 1$|⁠. In the |$\theta =1$| case, it is shown that the Laguerre–Bures ensemble is related to the Laguerre–Cauchy two-matrix model, notwithstanding the Bures ensemble corresponding to a Pfaffian point process. This carries over to the |$\theta $| -deformed case, allowing explicit expressions involving Fox H-functions for the correlation kernel, and its hard edge scaling limit, to also be obtained for the |$\theta $| -deformed Laguerre–Bures ensemble. The hard edge scaling limit is in the Raney class |$(\theta /2+1,1/2)$|⁠. [ABSTRACT FROM AUTHOR]

In this article, we consider the generalised two-parameter Cauchy two-matrix model and the corresponding integrable lattice equation. It is shown that with parameters chosen as 1 / k i , k i ∈ Z > 0 ( i = 1 , 2 ), the average characteristic polynomials admit (k 1 + k 2 + 2) -term recurrence relations, which can be interpreted as spectral problems for integrable lattices. The tau function is then given by the partition function of the generalised Cauchy two-matrix model as well as Gram determinant. The simplest solvable example is given. [ABSTRACT FROM AUTHOR]

In this article, we consider the Christoffel transformations for skew-orthogonal polynomials and partial-skew-orthogonal polynomials. We demonstrate that the Christoffel transformations can act as spectral problems for discrete integrable hierarchies, and therefore we derive certain integrable hierarchies from these transformations. Some reductional cases are also considered. [ABSTRACT FROM AUTHOR]

The eigenvalue probability density function for symplectic invariant random matrix ensembles can be generalized to discrete settings involving either a linear or an exponential lattice. The corresponding correlation functions can be expressed in terms of certain discrete and q skew orthogonal polynomials, respectively. We give a theory of both of these classes of polynomials, and the correlation kernels determining the correlation functions, in the cases in which the weights for the corresponding discrete unitary ensembles are classical. Crucial for this are certain difference operators which relate the relevant symmetric inner products to the skew symmetric ones, and have a tridiagonal action on the corresponding (discrete or q) orthogonal polynomials. [ABSTRACT FROM AUTHOR]

Abstract By adopting in situ nano-mechanical testing in transmission electron microscope, we reveal that nanoscale helium bubbles can simultaneously enhance strength and ductility in small-volume single-crystal Al-4Cu pillars, which breaks the paradox of trade-off between strength and ductility. Nanoscale helium bubbles serve as internal dislocation sources and shearable obstacles, which promote dislocation nucleation and storage, and give rise to higher flow stress, controllable plasticity and larger uniform deformation in Al-4Cu pillars. Nanoscale helium bubbles are rather stable under plastic straining. Bubble coarsening and coalescence are only observed at final localized deformation regime. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract Inspired by Okounkov's work (2001) [20] which relates KP hierarchy to determinant point process, we establish a relationship between BKP hierarchy and Pfaffian point process. We prove that the correlation function of the shifted Schur measures on strict partitions can be expressed as a Pfaffian of skew symmetric matrix kernel, whose elements are certain vacuum expectations of neutral fermions. We further show that the matrix integrals solution of BKP hierarchy can also induce a certain Pfaffian point process. [ABSTRACT FROM AUTHOR]

This paper mainly talks about the Cauchy two-matrix model and its corresponding integrable hierarchy with the help of orthogonal polynomial theory and Toda-type equations. Starting from the symmetric reduction in Cauchy biorthogonal polynomials, we derive the Toda equation of CKP type (or the C-Toda lattice) as well as its Lax pair by introducing time flows. Then, matrix integral solutions to the C-Toda lattice are extended to give solutions to the CKP hierarchy which reveals the time-dependent partition function of the Cauchy two-matrix model is nothing but the τ-function of the CKP hierarchy. At last, the connection between the Cauchy two-matrix model and Bures ensemble is established from the point of view of integrable systems. [ABSTRACT FROM AUTHOR]

To ascertain the role of the solidification cell structures on the mechanical performance of Al-Si-(Mg) alloys processed using the laser powder bed fusion (LPBF) technique, micropillar compression tests were performed on LPBF Al-10Si-0.3Mg (AlSi10Mg). The alloy's microstructure consists of submicron-scale cellular structures, dense dislocation networks, and dispersed nanoscale Si precipitates. The stress-strain responses of the micropillars are devoid of pronounced serrations and the yield strength and work hardening behaviors are size-independent. A comparison of the micropillar compression responses of the LPBF AlSi10Mg, 316 L stainless steel and Inconel 718 alloy, and nano-and micro-crystalline alloys is made. In LPBF AlSi10Mg, the combination of dislocation networks and shear-resistant Si particles resist the dislocation motion significantly and enhance dislocation storage. This results in the cellular structure dominating the strength and plastic flow. These results show a pathway for designing high strength alloys via additive manufacturing. [Display omitted] [ABSTRACT FROM AUTHOR]

Micropillar compression tests were performed on unalloyed Ni that was manufactured using the additive manufacturing (AM) technique of laser powder bed fusion (LPBF) with micropillar diameters ranging from 1 to 3.5 μm. In all cases, the single crystalline micropillars with the <110> crystallographic orientation, aligned along the build direction of LPBF and the uniaxial compression axis, are tested. In contrast to other LPBF alloys, in which submicron-scale cellular structures decorated with dense dislocation networks are often reported, only dislocation networks with relatively sparse dislocations along the network boundaries are observed in the LPBF Ni. Results of the micropillar compression tests show that the stress-strain responses of the LPBF Ni in the plastic regime are dominated by pronounced serrations and both the yield strength and work hardening behavior are highly dependent on the pillar diameter. Microscopic observations on the deformed pillars show that that the relatively low-density of dislocations in the microstructure of the LPBF Ni do not offer a substantial resistance to the dislocation motion. This is further verified by comparing the mechanical performance of the micropillars of the LPBF Ni with those of the pre-strained Ni, nanocrystalline Ni and 316L stainless steel manufactured via the directed energy deposition AM technique. [ABSTRACT FROM AUTHOR]

Energetic electron beams (e-beams) are used in the welding, 3D printing and imaging of various materials. It is commonly accepted that the e-beam irradiation inside transmission electron microscope has a negligible effect on the intrinsic mechanical properties of small-volume metallic materials during in situ investigation. However, as small-volume Al is usually covered by a thin layer of native oxide, we show here that high-energy (200 keV) e-beam irradiation can dramatically alter the deformation behavior. E-beam irradiation can drastically rejuvenate the amorphous structure of the oxide layer, producing a defective interface/surface, and promoting the transition of the deformation mode from internal dislocation multiplication to interface-dominated dislocation nucleation mediated plasticity, as indicated by the enhanced strain rate sensitivity and reduced activation volume. Moreover, the amorphous oxide layer undergoes viscous flow under the e-beam irradiation, such that nanoscale single-crystal Al confined by a 29% volume fraction of native oxide shell exhibits more than 60% uniform elongation. [ABSTRACT FROM AUTHOR]

Mechanically robust nanoscale metallic materials are highly desirable in many miniaturized devices. However, the lack of strain hardening and controllable plasticity plagues such small-volume metals. Using Al-4Cu alloy as an example, here we show that a submicron-sized metallic material with ultrathin native oxide shell exhibits a high degree of deformation controllability, unprecedented strain hardening, size strengthening and toughness, in uniaxial tensile deformation. The metal/native oxide “composite” is easy to make, and the emergent properties extend well beyond the benchmark range known for metals in a normalized (i.e., dimensionless) strength-toughness plot. The origin of the combination of strengthening and plastic stability is that an intact ultrathin native oxide shell exerts a strong confinement on dislocation movement and annihilation, thereby breaking the envelope on dislocation storage and strain hardening achievable in small-volume metals. [ABSTRACT FROM AUTHOR]

Solidification cells and a high density of dislocations are two common features of additively manufactured (AM) alloys that are processed using techniques such as laser powder bed fusion (L-PBF) and directed energy deposition (DED). A critical assessment of their role in determining the plastic properties (yield strength, σ y , and work hardening behavior) was performed via the micropillar compression tests on the austenitic 316L stainless steel (316L) and the Inconel 718 (IN718) alloys manufactured using the L-PBF and DED techniques, and comparing the results obtained with those of the compression and tensile tests on bulk samples. While both the L-PBF alloys contain submicron-scale cells whose boundaries are decorated with the dislocation networks, the DED 316L consists of micron-scale cells (whose boundaries are enriched with elemental segregation) with a uniform distribution of dislocations within them. The variations in σ y with the pillar size are similar to those reported on pillars fabricated from pre-strained Ni but are opposite to those reported on pillars of micro/nano-crystalline alloys. The mechanical responses of the DED 316L pillars with and without cell boundaries (CBs) are similar. These observations suggest that the high density of dislocations (arranged in the network fashion or distributed uniformly) —and not the CBs—determine σ y of the AM alloys. The stress-strain responses of pillars and transmission electron micrographs obtained on the deformed bulk samples suggest that the dislocation networks significantly enhance dislocation storage, leading to bulk-like deformation behaviors and superior work hardening capability in the L-PBF pillars with larger diameters. [Display omitted] [ABSTRACT FROM AUTHOR]

The relationship between the microstructural features (such as the solidification cells and initial dislocation densities) and the tensile properties of alloys additively manufactured (AM) using techniques such as laser powder bed fusion (L-PBF) and directed energy deposition (DED) is yet to be firmly established. In this work, a detailed investigation into the structure-property relations in DED 316L austenitic stainless steel (316L SS) was conducted. The microstructural parameters were varied systematically by changing the laser energy employed. Results show that while the sizes of grains and cells and the volume fraction of the oxide particles increase with increasing laser energy, the dislocation density decreases. Importantly, a uniform distribution of dislocations, instead of dislocation networks that are reported in many AM alloys, was observed. The connection between these microstructural features and the yield strength and work hardening capability of the DED 316L SS, which vary systematically with the laser energy, are explored. The correlation shows that a Hall-Petch type relation cannot capture the measured yield strength variation. Instead, the initial dislocation density dominates both the yield strength and the work hardening behavior. These results suggest a strategy for manipulating the mechanical performance in AM alloys through the control of dislocation densities and their distribution. [Display omitted] [ABSTRACT FROM AUTHOR]

ABSTRACT The objective of this study was to determine the pharmacokinetics of enrofloxacin and its metabolite, ciprofloxacin, in Nanyang cattle after a single intravenous (IV), and intramuscular (IM) administration of enrofloxacin at 2.5 mg/kg body weight (BW). Blood samples were collected at predetermined time points. Enrofloxacin and ciprofloxacin concentrations in plasma were simultaneously determined using a high‐performance liquid chromatography (HPLC) assay method and subjected to a non‐compartmental analysis. After IV administration, enrofloxacin had a mean (±SD) volume of distribution at steady state (VSS) of 1.394 ± 0.349 L/kg, a terminal half‐life (t1/2λz) of 3.592 ± 1.205 h, and a total body clearance (Cl) of 0.675 ± 0.16 L/h/kg. After IM administration, enrofloxacin was absorbed relatively slowly but completely, with a mean absorption time (MAT) of 6.051 ± 1.107 h and a bioavailability of 99.225 ± 7.389%. Both compounds were detected simultaneously in most plasma samples following both routes of administration, indicating efficient biotransformation of enrofloxacin to ciprofloxacin. After IV injection, the peak concentration (Cmax) of ciprofloxacin was 0.315 ± 0.017 μg/mL, observed at 0.958 ± 0.102 h. Following IM injection, the corresponding values were 0.071 ± 0.006 μg/mL and 3 ± 1.095 h, respectively. Following IV and IM administration, the conversion ratio of enrofloxacin to ciprofloxacin was calculated as 59.2 ± 9.6% and 31.2 ± 7.7%, respectively. The present results demonstrated favorable pharmacokinetic profiles for enrofloxacin, characterized by complete absorption with relatively slow kinetics, extensive distribution, efficient biotransformation to ciprofloxacin, and prolonged elimination in Nanyang cattle. [ABSTRACT FROM AUTHOR]

Previous works have considered the leading correction term to the scaled limit of various correlation functions and distributions for classical random matrix ensembles and their β generalisations at the hard and soft edge. It has been found that the functional form of this correction is given by a derivative operation applied to the leading term. In the present work we compute the leading correction term of the correlation kernel at the spectrum singularity for the circular Jacobi ensemble with Dyson indices β = 1 , 2 and 4, and also to the spectral density in the corresponding β -ensemble with β even. The former requires an analysis involving the Routh–Romanovski polynomials, while the latter is based on multidimensional integral formulas for generalised hypergeometric series based on Jack polynomials. In all cases this correction term is found to be related to the leading term by a derivative operation. [ABSTRACT FROM AUTHOR]

There is a two-component log-gas system with Boltzmann factor which provides an interpolation between the eigenvalue probability density function (PDF) for β = 1 and β = 4 invariant random matrix ensembles. Its solvability relies on the construction of particular skew orthogonal polynomials, with the skew inner product a linear combination of the β = 1 and β = 4 inner products, each involving weight functions. For suitably related classical weight functions, we seek to express the skew orthogonal polynomials as linear combinations of the underlying orthogonal polynomials. It is found that in each case (Gaussian, Laguerre, Jacobi and generalised Cauchy) the coefficients can be expressed in terms of hypergeometric polynomials with argument relating to the fugacity. In the Jacobi case, for example, the coefficients are Wilson polynomials. [ABSTRACT FROM AUTHOR]

Currently, the effects of different tillage modes on greenhouse gas (GHG) emissions, carbon footprint (CF), energy budget and net ecosystem economic efficiency (NEEE) in rice fields remain unclear. In the present study, three tillage modes were tested, including rice conventional cultivation with intensive till (CT), conventional flat cultivation with no-till (FNT) and ridge cultivation with no-till (RNT) in Dafasi town, Wuxue city, Hubei province, China. This study for the first time evaluates the effects of RNT on agricultural GHG emissions, grain yield, CF, energy budget and NEEE. Compared with CT and FNT, RNT reduced the soil CH 4 emissions by 29.5% and 9.9%, respectively. CT resulted in 15.8% and 23.1% lower total GHG emissions than FNT and RNT, respectively, due to lower soil CH 4 emissions. Moreover, RNT significant decreased the CF by 35.7% and 18.2% relative to CT and FNT, respectively. The net energy, energy efficiency and energy productivity under RNT were 41.2%, 25.0% and 26.7% higher than those under CT, respectively, while the specific energy under RNT was 24.7% lower than that under CT. The NEEE under RNT was 1.66 and 1.20 folds of that under CT and FNT, respectively. In conclusion, this study recommends that RNT is an environmentally safe tillage mode for reducing GHG emissions and CF, and improving energy use efficiency and NEEE for rice production in China and similar agro-eco-regions elsewhere in the world. [ABSTRACT FROM AUTHOR]

Coke powders in the coking wastewater generated by petroleum refining industry needs to be removed to achieve water reuse for lack of water resources. This study developed a decoking hydrocyclone in the closed coking wastewater circulation treatment system to remove coke powders, which was highly efficient and environmentally friendly. Computational Fluid Dynamics (CFD) method was carried out to study the tangential velocity distribution index n-value to guide design of decoking hydrocyclone and experiment was conducted to verify the coke powders removal effect. It was found that the increase of n-value is conducive to the improvement of coke powders separation efficiency. A decoking hydrocyclone with a cone angle of 15° and an inlet size of 4 × 6 mm is the optimum hydrocyclone and the recovery efficiency of coke powders is stable at more than 90%. It is the first time for hydrocyclone successfully applied to the removal of coke powders in coking wastewater in the decoking process of petroleum refining industry, in which the separation efficiency of coke powders is considerably improved. Unlabelled Image • Solid-liquid hydrocyclone is first applied to remove coke powders in coking wastewater. • CFD method and tangential velocity distribution index n-value is studied to optimize the hydrocyclone. • Coke powders recovery rate is stable above 90% in industry application. [ABSTRACT FROM AUTHOR]

Helium (He) bubbles are typical radiation defects in structural materials in nuclear reactors after high dose energetic particle irradiation. In the past decades, extensive studies have been conducted to explore the dynamic evolution of He bubbles under various conditions and to investigate He-induced hardening and embrittlement. In this review, we summarize the current understanding of the behavior of He bubbles in metals; overview the mechanisms of He bubble nucleation, growth, and coarsening; introduce the latest methods of He control by using interfaces in nanocrystalline metals and metallic multilayers; analyze the effects of He bubbles on strength and ductility of metals; and point out some remaining questions related to He bubbles that are crucial for design of advanced radiation-tolerant materials. [ABSTRACT FROM AUTHOR]

5-Methylcytosine (m5C) plays an extremely important role in the basic biochemical process. With the great increase of identified m5C sites in a wide variety of organisms, their epigenetic roles become largely unknown. Hence, accurate identification of m5C site is a key step in understanding its biological functions. Over the past several years, more attentions have been paid on the identification of m5C sites in multiple species. In this work, we firstly summarized the current progresses in computational prediction of m5C sites and then constructed a more powerful and reliable model for identifying m5C sites. To train the model, we collected experimentally confirmed m5C data from Homo sapiens , Mus musculus , Saccharomyces cerevisiae and Arabidopsis thaliana , and compared the performances of different feature extraction methods and classification algorithms for optimizing prediction model. Based on the optimal model, a novel predictor called iRNA-m5C was developed for the recognition of m5C sites. Finally, we critically evaluated the performance of iRNA-m5C and compared it with existing methods. The result showed that iRNA-m5C could produce the best prediction performance. We hope that this paper could provide a guide on the computational identification of m5C site and also anticipate that the proposed iRNA-m5C will become a powerful tool for large scale identification of m5C sites. [ABSTRACT FROM AUTHOR]

Abstract The Novikov equation is an integrable analogue of the Camassa–Holm equation with a cubic (rather than quadratic) nonlinear term. Both these equations support a special family of weak solutions called multipeakon solutions. In this paper, an approach involving Pfaffians is applied to study multipeakons of the Novikov equation. First, we show that the Novikov peakon ODEs describe an isospectral flow on the manifold cut out by certain Pfaffian identities. Then, a link between the Novikov peakons and the finite Toda lattice of BKP type (B-Toda lattice) is established based on the use of Pfaffians. Finally, certain generalizations of the Novikov equation and the finite B-Toda lattice are proposed together with special solutions. To our knowledge, it is the first time that the peakon problem is interpreted in terms of Pfaffians. [ABSTRACT FROM AUTHOR]

Abstract Firstly, a formal correspondence is established between the Camassa–Holm (CH) equation and a two-component modified CH (or called SQQ) equation according to the method of moment modification for multipeakon formulae. Secondly, based on the generalized nonisospectral CH equation in Chang et al. (2014) [14] and the interlacing multipeakons of the two-component modified CH equation in Chang et al. (2016) [15] , we propose a new generalized two-component modified CH equation with two parameters, which possesses a nonisospectral Lax pair. The proposed equation still admits multipeakon solutions of explicit and closed form. Sufficient conditions for global existence of solutions are given and two concrete examples with certain interesting phenomenon are presented. Last of all, as a by-product, a generalized nonisospectral modified CH equation is deduced, together with its Lax pair. [ABSTRACT FROM AUTHOR]

Using a modified laser powder bed fusion (LPBF) technique, a compositionally graded Cu-Ni alloy was fabricated. Through microstructural and mechanical characterization on the samples extracted from it, the addition of 7.6 wt.% Ni to Cu is identified as the minimum required for obtaining a crack-free and nearly-fully-dense coupons using LPBF. Subsequently, 3 wt.% Al was added to the Cu-7.6 wt.% alloy to deplete the solute Ni atoms from the matrix through the precipitation of Ni 3 Al upon aging of the LPBF Cu-Ni-Al alloy, which simultaneously enhances the strength and electrical conductance of the alloy. Through this example, we demonstrate the potential of high-throughput screening of alloys suitable for LPBF through the fabrication of the compositionally graded alloys and subsequent alloy design for optimum property combinations. [Display omitted] [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) as types of proton conductive materials have attracted much attention. Here, an acylamide-functionalized 3D MOF, [Ni3(TPBTC)2(stp)2(H2O)4]·2DMA·32H2O, has been successfully constructed via combining Ni(NO3)2, TPBTC (TPBTC = benzene-1,3,5-tricarboxylic acid tris-pyridin-4-ylamide) and 2-H2stp (2-H2stp = 2-sulfoterephthalic acid monosodium salt) under solvothermal conditions. Single-crystal X-ray diffraction revealed that there are uncoordinated guest DMA molecules in the pores of the compound. On removal of guest DMA molecules, the proton conductivity of the compound increased to 2.25 × 10−3 S cm−1 at 80 °C and 98% RH which is about 110 times that of the original material. It is hoped that this work can provide essential insight for designing and obtaining improved crystalline-state proton conducting materials by considering the influences of guest molecules on proton conduction properties of porous materials. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of home‐based telerehabilitation based on the Internet‐based rehabilitation management system on hip function, activities of daily living and somatic integrative ability of elderly postoperative hip fracture patients. Methods: From June 2020 to November 2020, we recruited 58 elderly postoperative hip fracture patients and randomly assigned them to the telephone group (n = 29) and the telerehabilitation group (n = 29). Both groups received routine discharge instructions, and the former received telephone follow‐up after discharge, while the latter received remote rehabilitation based on the Internet‐based rehabilitation management system. The Harris hip score (HHS), functional independence measure (FIM), timed up‐and‐go test (TUG), and short physical performance battery (SPPB) were used to evaluate the patients' hip function, activities of daily living, and overall somatic ability. Results: There was no significant difference between the baseline data of the two groups before the intervention (P > 0.05); no matter after hip replacement or internal fixation, the HHS score and FIM score of both groups increased gradually with the postoperative time, and the scores in the telerehabilitation group were higher than those in the telephone group at 1 and 3 months after the intervention, and the difference was significant (P < 0.05); for patients after hip replacement, the TUG and SPPB scores in the telerehabilitation group were better than those in the telephone group at 3 months after the intervention, and the difference was significant (P < 0.05). Conclusions: The Internet‐based rehabilitation management system applied to postoperative home rehabilitation of elderly hip fracture patients can improve the functional recovery of the hip joint and enhance the ability to perform activities of daily living and somatic integration to a certain extent. This seems to provide an effective option for conducting home rehabilitation. [ABSTRACT FROM AUTHOR]

The microstructure, hardness, impact toughness, and tensile properties of Haynes®282 alloy subjected to accelerated ageing at three temperature and time combinations were studied. Microstructural examination revealed that ageing promotes grain growth, the precipitation and coarsening of various phases and carbides in the matrix and at grain boundaries. While the ageing temperature and time has a minimal effect on the hardness and strength, it significantly deteriorates the ductility and impact strength of the alloy. Elevated temperature tensile behavior reveals that this alloy shows serrated flow due to dynamic strain ageing, and the type of serrations depends on the ageing treatment. In the as-received condition, serrations change from type A to a mixture of type A and type B, and further to type C with increase in strain. Alternately, only type C serrations are present on the flow curves of all the aged alloys. Dislocation interactions with interstitial solutes and substitutional solutes are responsible for the type A and mixture of type A and type B serrations, and type C serrations, respectively. Prolonged ageing also changes the deformation mode from planar slip to wavy slip on the account of γ' coarsening. Fractographic examination of tensile tested and impact tested specimens indicated that the fracture mechanism transitions from ductile fracture with dimple features to brittle inter-granular features with an increase in the ageing duration. It was inferred that continuous inter-connected carbide network formed during ageing was responsible for reduction in ductility and impact strength. • Ageing led to precipitation of inter-connected grain boundary carbide network and a TCP μ phase. • Increase in ageing duration led to drastic reduction of impact strength and tensile ductility, and changed fractured surface from ductile dimples to brittle inter-granular features. • Tensile strength increased with ageing treatments, however, it remained nearly same with increase in ageing duration. • Mechanism of deformation changed from planar slip to wavy slip with increase in ageing duration. • Serrations appeared on tensile flow curves due to dynamic strain ageing and their changes with increase in strain and ageing duration are elucidated in this study. [ABSTRACT FROM AUTHOR]

The microstructure, hardness, impact toughness, and tensile properties of Haynes®282 alloy subjected to accelerated ageing at three temperature and time combinations were studied. Microstructural examination revealed that ageing promotes grain growth, the precipitation and coarsening of various phases and carbides in the matrix and at grain boundaries. While the ageing temperature and time has a minimal effect on the hardness and strength, it significantly deteriorates the ductility and impact strength of the alloy. Elevated temperature tensile behavior reveals that this alloy shows serrated flow due to dynamic strain ageing, and the type of serrations depends on the ageing treatment. In the as-received condition, serrations change from type A to a mixture of type A and type B, and further to type C with increase in strain. Alternately, only type C serrations are present on the flow curves of all the aged alloys. Dislocation interactions with interstitial solutes and substitutional solutes are responsible for the type A and mixture of type A and type B serrations, and type C serrations, respectively. Prolonged ageing also changes the deformation mode from planar slip to wavy slip on the account of γ' coarsening. Fractographic examination of tensile tested and impact tested specimens indicated that the fracture mechanism transitions from ductile fracture with dimple features to brittle inter-granular features with an increase in the ageing duration. It was inferred that continuous inter-connected carbide network formed during ageing was responsible for reduction in ductility and impact strength. • Ageing led to precipitation of inter-connected grain boundary carbide network and a TCP μ phase. • Increase in ageing duration led to drastic reduction of impact strength and tensile ductility, and changed fractured surface from ductile dimples to brittle inter-granular features. • Tensile strength increased with ageing treatments, however, it remained nearly same with increase in ageing duration. • Mechanism of deformation changed from planar slip to wavy slip with increase in ageing duration. • Serrations appeared on tensile flow curves due to dynamic strain ageing and their changes with increase in strain and ageing duration are elucidated in this study. [ABSTRACT FROM AUTHOR]

Background: To avoid the inconvenience of triangulation among various rigid operating instruments in mediastinoscopy-assisted esophagectomy, we invented a new technique: used a flexible endoscope to mobilize thoracic esophagus and dissected mediastinal lymph nodes through the left cervical incision. This technology has not been reported so far. In this study, we introduce our long-term experience and demonstrate this new technique. Methods: Twenty-nine patients with early esophageal cancer underwent mediastinoscopy-assisted esophagectomy in our hospital from June 2018 to September 2020. Among them, 12 patients used flexible mediastinoscopy, and 17 patients used conventional rigid mediastinoscopy and instruments to observe their therapeutic effect. Results: There were no significant differences between the two groups in gender, average age, body mass index, incidence of adverse reactions, bleeding volume, and postoperative hospital stay. The operation time of flexible mediastinoscopy group was significantly shorter than that of rigid mediastinoscopy group (192.9 ± 13.0 vs 246.8 ± 6.9 min, p < 0.01). The number of lymph nodes removed by flexible endoscopy was significantly more than that of rigid endoscopy (8.5 ± 0.6 vs 6.0 ± 0.3, P < 0.01). Postoperative follow-up was completed for all patients, and the average follow-up time was 11.6 ± 7.2 months. During the follow-up period, no recurrence or death was observed. Conclusions: Mediastinoscopy-assisted esophagectomy is an effective way to treat early esophageal cancer. The application of flexible mediastinoscopy provides more convenience and better stability. It can facilitate the operation of the surgeon and lymph node dissection, which proved to be a feasible technology. [ABSTRACT FROM AUTHOR]

In this paper, an orthogonal polynomials-based (OPs-based) approach to generate discrete moving frames and invariants is developed. It is shown that OPs can provide explicit expressions for the discrete moving frame as well as the associated difference invariants, and this approach enables one to obtain the corresponding discrete invariant curve flows simultaneously. Several examples in the cases of centro-affine plane, pseudo-Euclidean plane, and high-dimensional centro-affine space are presented. [ABSTRACT FROM AUTHOR]

Background: Catamenial pneumothorax is characterized by spontaneous recurring pneumothorax during menstruation, which is a common clinical manifestation of thoracic endometriosis syndrome. There are still controversies about its pathogenesis.Case Presentation: A 43-year-old woman with a history of endometriosis came to our hospital due to recurring pneumothorax during menstruation. Uniportal Video-assisted Thoracoscopic Surgery (VATS) exploration was performed on the eve of menstruating. We thoroughly explored the diaphragm, visceral and parietal pleura: The lung surface was scattered with yellowish-brown implants; no bullae were found; multiple diaphragmatic defects were found on the dome. And surprisingly, we caught a fascinating phenomenon: Bubbles were slipping into pleural cavity through diaphragmatic defects. We excised the diaphragmatic lesions and wedge resected the right upper lung lesion; cleared the deposits and flushed the thoracic cavity with pure iodophor. Diaphragmatic lesions confirmed the presence of endometriosis, and interestingly enough, microscopically, endometrial cells were shedding with impending menses. After a series of intraoperative operations and postoperative endocrine therapy, the disease did not recur after a period of follow-up.Conclusion: We have witnessed the typical signs of catamenial pneumothorax at the accurate timing: Not only observed the process of gas migration macroscopically, but also obtained pathological evidence of diaphragmatic periodic perforation microscopically, which is especially precious and confirms the existing theory that retrograde menstruation leads to diaphragmatic endometriosis, and the diaphragmatic fenestration is obtained due to the periodic activities of ectopic endometrium. [ABSTRACT FROM AUTHOR]

Background/Aims: Targeted drug delivery vehicles with low immunogenicity and toxicity are needed for cancer therapy. Here, we prepare an active targeting drug carrier of low immunogenicity and toxicity for targeted therapy. Methods: Immature dendritic cells (imDCs) from BALB/c mice were used as donor cells of exosomes (Exos) that were transfected with the plasmids expressing fusion proteins of a tumor-targeting peptide known as internalizing RGD (iRGD) to construct a type of tumor-targeting iRGD-Exos and observe the interaction between these iRGD-Exos. Also, recombinant methioninase (rMETase) was loaded into the iRGD-Exos by electroporation to construct iRGD-Exos-rMETase and to assess the tumor-targeting function of the iRGD-Exos-rMETase. Finally, 30 BALB/c were randomly divided into five groups (n = 6), to observe tumor growth in vivo. Results: The iRGD-Exos-rMETase was 99.58 nm in diameter and presented a unique "goblet" structure under transmission electron microscopy (TEM), with the encapsulation efficiency (EE) of 19.05%. iRGD-Exos-rMETase group has the strongest tumor suppressive effect. Compared to the iRGD-Exos-rMETase group, rMETase group and the blank-Exos-rMETase group were less effective, while the PBS group and the iRGD-Exos group showed no inhibitory effect on tumor growth. After treatment, the iRGD-Exos-rMETase group had gastric tumors significantly smaller and lighter than the other groups (P < 0.05). Conclusion: The iRGD-Exos-rMETase is an effective antitumor therapy that delivers rMETase to tumor tissue using the iRGD-Exos. With its favorable inhibitory effect and tumor-targeting function, the iRGD-Exos-rMETase shows excellent potential value and exciting prospects in clinical applications. [ABSTRACT FROM AUTHOR]

Cancer stem cells are undifferentiated cancer cells that have self‐renewal ability, a high tumorigenic activity, and a multilineage differentiation potential. MicroRNAs play a critical role in regulating gene expression during carcinogenesis. Here, we investigated the role of miR‐7 and the mechanism by which it is dysregulated in gastric cancer stem cells (GCSCs). The stem cell marker, CD44, was used to sort GCSCs by fluorescence‐activated cell sorting. We found that CD44 (+) cells have higher invasiveness and form more number of sphere colonies than CD44 (−) cells. Quantitative real‐time polymerase chain reaction (PCR) revealed that the miR‐7‐5p expression was remarkably downregulated in GCSCs but was significantly increased in the methionine‐deprived medium. The downregulation of miR‐7‐5p results from the increased DNA methylation in the promoter region using the methylation‐specific PCR. Overexpression of miR‐7‐5p reduced the formation of colony and decreased the invasion of GCSCs through targeting Smo and Hes1 and subsequent repressing Notch and Hedgehog signaling pathways in vitro. Notably, upregulating miR‐7‐5p inhibited the growth of tumor in the xenograft model. Hence, these data demonstrated that miR‐7‐5p represses GCSC invasion through inhibition of Smo and Hes1, which provides a potential therapeutic target of gastric cancer treatment. [ABSTRACT FROM AUTHOR]

Background: Autophagy plays an important role in regulating cisplatin (CDDP) resistance in gastric cancer cells. However, the underlying mechanism of methioninase (METase) in the regulation of autophagy and CDDP resistance of gastric cancer cells is still not clear. Materials and methods: Western blot was used to detect the levels of autophagy-related proteins, multidrug-resistant 1 (MDR-1), and FoxM1 protein. LncRNA HULC was detected by qRT-PCR. Cell viability was detected using CCK-8 assay. The interaction between lncRNA HULC and FoxM1 was confirmed by RNA pull-down and RIP assay. Results: Lentiviral vector carrying METase (LV-METase) suppressed autophagy and CDDP resistance of drug-resistant gastric cancer cells. LncRNA HULC was significantly downregulated in drug-resistant gastric cancer cells transfected with LV-METase. Besides, we found that lncRNA HULC interacted with FoxM1. In addition, METase suppressed autophagy to reduce CDDP resistance of drug-resistant gastric cancer cells through regulating HULC/FoxM1, and interfering HULC suppressed autophagy to reduce CDDP resistance of drug-resistant gastric cancer cells through regulating FoxM1. Finally, interfering HULC inhibited tumor growth in vivo. Conclusion: METase suppressed autophagy to reduce CDDP resistance of drug-resistant gastric cancer cells through regulating HULC/FoxM1 pathway. [ABSTRACT FROM AUTHOR]

Skew-orthogonal polynomials (SOPs) arise in the study of the n-point distribution function for orthogonal and symplectic random matrix ensembles. Motivated by the average of characteristic polynomials of the Bures random matrix ensemble studied in Forrester and Kieburg (Commun Math Phys 342(1):151-187, 2016), we propose the concept of partial-skew-orthogonal polynomials (PSOPs) as a modification of the SOPs, and then the PSOPs with a variety of special skew-symmetric kernels and weight functions are addressed. By considering appropriate deformations of the weight functions, we derive nine integrable lattices in different dimensions. As a consequence, the tau-functions for these systems are shown to be expressed in terms of Pfaffians and the wave vectors PSOPs. In fact, the tau-functions also admit the multiple integral representations. Among these integrable lattices, some of them are known, while the others are novel to the best of our knowledge. In particular, one integrable lattice is related to the partition function of the Bures ensemble. Besides, we derive a discrete integrable lattice which can be used to compute certain vector Padé approximants. This yields the first example regarding the connection between integrable lattices and generalised inverse vector-valued Padé approximants, about which Hietarinta, Joshi, and Nijhoff pointed out that, “This field remains largely to be explored”, in the recent monograph (Hietarinta et al. in Discrete systems and integrability, vol 54. Cambridge University Press, Cambridge, 2016, [Section 4.4]). [ABSTRACT FROM AUTHOR]

In the literature, most known sequence transformations can be written as a ratio of two determinants. But, it is not always this case. One exception is that the sequence transformation proposed by Brezinski, Durbin, and Redivo-Zaglia cannot be expressed as a ratio of two determinants. Motivated by this, we will introduce a new algebraic tool—pfaffians, instead of determinants in the paper. It turns out that Brezinski-Durbin-Redivo-Zaglia’s transformation can be expressed as a ratio of two pfaffians. To the best of our knowledge, this is the first time to introduce pfaffians in the expressions of sequence transformations. Furthermore, an extended transformation of high order is presented in terms of pfaffians and a new convergence acceleration algorithm for implementing the transformation is constructed. Then, the Lax pair of the recursive algorithm is obtained which implies that the algorithm is integrable. Numerical examples with applications of the algorithm are also presented. [ABSTRACT FROM AUTHOR]

Numerous studies have reported effects of straws with microbial decaying agents on greenhouse gas emissions from rice fields. However, studies regarding the effects of microbial decaying agents on carbon footprint and economic profit under diverse water regimes remained unclear. A two-factor field experiment was adopted to assess effects of different straw treatments (straw returning alone abbreviated as S, and straw returning with microbial decaying agent abbreviated as SMD) on CH 4 and N 2 O emissions, rice yield, carbon footprint, economic profit and net ecosystem economic profit (NEEP) from paddy field under different water regimes (continuous flooding abbreviated as F, and alternation of wetting and drying abbreviated as AWD) in central China. Compared with S treatment, SMD treatment significantly enhanced the crop water productivity by 7.9%−8.4% and the rice yield by 7.3%−7.7%. Though SMD treatment increased the economic profit by 9.9%−18.5%, and the NEEP by 9.6%−18.0% relative to S treatment, it also resulted in higher the CH 4 emissions by 12.7%−32.4% and global warming potential by 11.2%−21.5% regardless of water regimes. Water regimes had significant effects on the crop water productivity, rice yield, CH 4 and N 2 O emissions, global warming potential, economic profit, NEEP and carbon footprint. Compared with F treatment, AWD treatment improved the crop water productivity by 51.7%−79.4%, maintained rice yield, increased N 2 O emissions by 17.7%−40.0%, and mitigated CH 4 emissions by 33.2%−75.1%, which therefore resulted in lower global warming potential by 31.5%−69.8% and carbon footprint by 32.7%−66.0%. Moreover, AWD treatment significantly increased the economic profit by 25.4%−41.9% and the NEEP by 28.8%−46.6% relative to F treatment. Overall, the straw incorporated with microbial decaying agents is not an environmental friendly practice for the tradeoff of mitigation of CH 4 emissions and increase in economic profit. It is necessary to further optimize straw treatment for mitigating CH 4 emissions in order to develop rice sustainable production. • AWD irrigation reduced carbon footprint while increased economic profit. • Straws with microbial decaying agents increased rice yield and economic profit. • Straws with microbial decaying agents did not affect carbon footprint. • Straws with microbial decaying agents boosted CH 4 emissions and GWP. [ABSTRACT FROM AUTHOR]

[Display omitted] • Promoter plays a key role in gene transcription regulation. • We presented a database PPD, which collected the experimentally validated promoters in prokaryotes. • PPD recorded 129,148 promoters across 63 prokaryotic species. • PPD provided an online genome browser for the visualization of the resources of prokaryotic promoter. • PPD might be a novel resource for the study of prokaryotic gene transcription. As a key region, promoter plays a key role in transcription regulation. A eukaryotic promoter database called EPD has been constructed to store eukaryotic POL II promoters. Although there are some promoter databases for specific prokaryotic species or specific promoter type, such as RegulonDB for Escherichia coli K-12, DBTBS for Bacillus subtilis and Pro54DB for sigma 54 promoter, because of the diversity of prokaryotes and the development of sequencing technology, huge amounts of prokaryotic promoters are scattered in numerous published articles, which is inconvenient for researchers to explore the process of gene regulation in prokaryotes. In this study, we constructed a Prokaryotic Promoter Database (PPD), which records the experimentally validated promoters in prokaryotes, from published articles. Up to now, PPD has stored 129,148 promoters across 63 prokaryotic species manually extracted from published papers. We provided a friendly interface for users to browse, search, blast, visualize, submit and download data. The PPD will provide relatively comprehensive resources of prokaryotic promoter for the study of prokaryotic gene transcription. The PPD is freely available and easy accessed at http://lin-group.cn/database/ppd/. [ABSTRACT FROM AUTHOR]