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In this study, we synthesized Fe3O4 nanoparticles (Fe3O4 NPs) of varying sizes and morphologies using the solvothermal method and incorporated them as additives into carbonyl iron magnetorheological fluids (CI-MRFs). We tested the shear stress, yield stress, viscosity and storage modulus of the MRFs using a magnetorheometer to investigate how the size and morphology of Fe3O4 NPs influence the performance of MRFs. Our results indicate that the size of the additive nanoparticles significantly enhances the MR properties of MRFs more than their morphological attributes. This enhancement results from optimizing and stabilizing the CI magnetic chain structure of the nanoparticles in the presence of a magnetic field. Specifically, MRFs with Fe3O4 NPs averaging 250 nm in size exhibit higher yield stress and storage modulus and show increased resistance to shear strains. Although the nanoparticle morphology has a modest effect on the rheological properties of MRFs, hexahedral and octahedral particles can enhance rheological properties through increased internal friction compared to spherical particles. Additionally, Fe3O4 NPs of different sizes and morphologies improve the sedimentation stability of MRFs, with those around 250 nm being particularly effective at slowing down sedimentation. Both hexahedral and octahedral Fe3O4 NPs slow down sedimentation more effectively than spherical Fe3O4 NPs. This paper investigates the rheological properties of CI-MRFs by controlling the additive particle size and morphological features, providing a research foundation for the design and optimization of MRFs. [ABSTRACT FROM AUTHOR]

The Space–Air–Ground Integrated Network (SAGIN) expands cyberspace greatly. Dynamic network architecture, complex communication links, limited resources, and diverse environments make SAGIN's authentication and key distribution much more difficult. Public key cryptography is a better choice for terminals to access SAGIN dynamically, but it is time-consuming. The semiconductor superlattice (SSL) is a strong Physical Unclonable Function (PUF) to be the hardware root of security, and the matched SSL pairs can achieve full entropy key distribution through an insecure public channel. Thus, an access authentication and key distribution scheme is proposed. The inherent security of SSL makes the authentication and key distribution spontaneously achieved without a key management burden and solves the assumption that excellent performance is based on pre-shared symmetric keys. The proposed scheme achieves the intended authentication, confidentiality, integrity, and forward security, which can defend against masquerade attacks, replay attacks, and man-in-the-middle attacks. The formal security analysis substantiates the security goal. The performance evaluation results confirm that the proposed protocols have an obvious advantage over the elliptic curve or bilinear pairings-based protocols. Compared with the protocols based on the pre-distributed symmetric key, our scheme shows unconditional security and dynamic key management with the same level performance. [ABSTRACT FROM AUTHOR]

Objective. Adopting hearts from donation after circulatory death (DCD) is a promising approach to enlarge the donor pool. Nevertheless, DCD hearts experience severe warm ischemia/reperfusion (I/R) injury. Recent studies have demonstrated that conditioned medium (CM) derived from bone marrow mesenchymal stem cells (BMSCs) has the potential of reducing organ I/R injury. Therefore, we investigated whether DCD heart preservation with normothermic ex vivo heart perfusion (EVHP) and BMSCs-CM treatment could alleviate myocardial warm I/R injury in the DCD hearts. Methods. We randomly divided donor rats into two groups: (1) DCD-Control group and (2) DCD-CM group. Before DCD heart preservation with the normothermic EVHP system for 105 minutes, rats suffered from a 25-minute warm ischemia injury in the DCD procedure. Vehicle or CM (300 μl) was added to the perfusate at the beginning of the perfusion process. The cardiac function of DCD hearts in the DCD-Control and DCD-CM groups was measured every 30 minutes. Besides, non-DCD hearts were harvested from the beating-heart rats. Results. The antibody array demonstrated that the CM contained 14 bioactive factors involved in apoptosis, inflammation, and oxidative stress. Warm ischemia injury resulted in a significant increase in the level of oxidative stress, inflammation, and apoptosis in the DCD hearts of DCD-Control group. Furthermore, compared with the DCD-Control group, CM treatment increased the developed pressure, dP / d t max and dP / d t min of the left ventricular in the DCD hearts during a 90-minute EVHP. Moreover, the administration of CM attenuated the level of oxidative stress, inflammation, and apoptosis in the DCD hearts of the DCD-CM group. Conclusions. Normothermic EVHP combined with CM treatment can alleviate warm I/R injury in the DCD hearts by decreasing the level of oxidative stress, inflammatory response, and apoptosis, which might alleviate the shortage of donor hearts by adopting DCD hearts. [ABSTRACT FROM AUTHOR]

Cancer constitutes a severe threat to human health and quality of life and is one of the most significant causes of morbidity and mortality worldwide. Natural dietary products have drawn substantial attention in cancer treatment and prevention due to their availability and absence of toxicity. Rosmarinic acid (RA) is known for its excellent antioxidant properties and is safe and effective in preventing and inhibiting tumors. This review summarizes recent publications on culture techniques, extraction processes, and anti-tumor applications of RA-enriched dietary supplements. We discuss techniques to improve RA bioavailability and provide a mechanistic discussion of RA regarding tumor prevention, treatment, and adjuvant therapy. RA exhibits anticancer activity by regulating oxidative stress, chronic inflammation, cell cycle, apoptosis, and metastasis. These data suggest that daily use of RA-enriched dietary supplements can contribute to tumor prevention and treatment. RA has the potential for application in anti-tumor drug development. [ABSTRACT FROM AUTHOR]

The simultaneous detection of a group of nine steroid hormones including six estrogens (17β-estradiol, estriol, estrone, ethinyl estradiol, diethylstilbestrol, and hexestrol), two glucocorticoids (dexamethasone, and hydrocortisone), and one progestogen (17α-hydoxyprogesterone) in milk powder and milk was performed. A modified QuEChERS method combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for analysis of the target compounds. To optimize the chromatographic conditions and QuEChERS process, the mobile phase additive, the amount of extraction solvent and the sorbent type were investigated, respectively. Under optimal conditions, the methodology applied to milk powder and milk was validated using five internal standards showing good linearity (R2 ≥ 0.9955 and 0.9925), recovery (83.8–119.5% and 87.9–117.7%), intra-precision (2.9–9.5% and 2.1–12.1%), inter-precision (1.6–11.0% and 3.1–9.9%) and the limit of quantification (0.01–2.2 μg kg−1 and 0.01–2.0 μg L−1). Finally, the analysis of commercial milk products revealed the presence of 17α-hydoxyprogesterone, hydrocortisone, dexamethasone, 17β-estradiol, and estrone in these samples. [ABSTRACT FROM AUTHOR]

This paper presents a stochastic stable control protocol for heterogeneous vehicle platoon subject to communication topologies change, external disturbance, and information delay. First, a random vehicle platoon system composed entirely of several pure electric vehicles is built. The random variation of data transmission link among the platoon in a natural traffic environment is considered and molded by the Markov chain combined with the directed graph method. The influence of delays and discrete data in wireless communication, road slope, and air resistance on the vehicle platoon is also considered by introducing the external interferences and equivalent information delays. Additionally, to ensure the vehicle platoon’s inner-vehicle stability, the variable-gain distributed controller is proposed based on the Markovian jumping system stability theory and $ H_\infty$ control. Finally, the $ \mathcal {L}_{2}$ stochastic string stability is defined to attenuate perturbations as they propagate through the platoon. Simulation studies about a vehicle platoon under four communication topologies random switching with two different control methods are provided to verify the theoretical result. It is shown that, compared to traditional platoon robust control, it is possible to achieve the vehicle platoon’s stability even if in the continuous mutation of unstable topologies by using the proposed control approach. [ABSTRACT FROM AUTHOR]

The rapid development of science and technology has created favorable conditions for Connected and Automated Vehicles (CAVs). Accurate localization is one of the fundamental functions of CAV to realize some advanced operations such as vehicle platooning. However, complicated urban traffic environments, such as the flyover, significantly influence vehicular positioning accuracy. The inability of CAV to accurately perceive self-localization information has become an urgent issue to be addressed. This paper proposed a novel cooperative localization method by introducing the relative Direction-of-Arrival (DOA) and Relative Distance (RD) into CAV to improve the localization accuracy of CAV in the multivehicle environment. First, the three-dimensional positioning error model of the host vehicle concerning adjacent vehicles in azimuth angle and pitch angle and intervehicle distances under the vehicle-to-vehicle communication was established. Second, two least-squares estimation algorithms, linear and nonlinear, are established to decrease the position errors by combining relative DOA and RD measurement information. To verify the proposed algorithm's effect, the PreScan-Simulink joint simulation is carried out. The results show that the host vehicle's localization accuracy by the proposed method can be improved by 25% compared with direct linearization. Besides, by combining relative DOA and relative RD measurement, the locating capability of the least-square-based nonlinear optimization method can be enhanced by 22%. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the biotransformation of the neonicotinoid pesticide sulfoxaflor and the metabolic responses in Sprague‐Dawley rats. Sulfoxaflor transformation was catalyzed by cytochrome P450 while five phase I and four phase II metabolites were identified for the first time in vivo. The experimental results demonstrated that sulfoxaflor brought about the metabolic profiling disturbances in liver and bile. Exposure to sulfoxaflor caused dysregulation of bile acid synthesis and reabsorption by the expression of farnesoid X receptor (FXR). Our data provided insights into biotransformation of chemicals while enabling the implementation of a new toolbox for the design of sulfoximine compounds. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the biotransformation of the neonicotinoid pesticide sulfoxaflor and the metabolic responses in Sprague‐Dawley rats. Sulfoxaflor transformation was catalyzed by cytochrome P450 while five phase I and four phase II metabolites were identified for the first time in vivo. The experimental results demonstrated that sulfoxaflor brought about the metabolic profiling disturbances in liver and bile. Exposure to sulfoxaflor caused dysregulation of bile acid synthesis and reabsorption by the expression of farnesoid X receptor (FXR). Our data provided insights into biotransformation of chemicals while enabling the implementation of a new toolbox for the design of sulfoximine compounds. [ABSTRACT FROM AUTHOR]

Vehicle dynamics plays a significant role on the formation of a vehicle platoon, especially at high speed condition. This paper proposes a distributed platoon formation framework for homogeneous autonomous vehicles which takes the vehicle dynamics into consideration. The boundaries of vehicle stability are firstly calculated by considering both lateral dynamics and actuator saturation. By combining the stability boundaries with multi-objective flocking (MOF) algorithm, a distributed formation controller is designed, which can form the vehicle platoon with high cruising speed steadily and rapidly. In addition, a low-level tracking controller is proposed to constitute a hierarchical control architecture which can achieve stable and accurate formation of platoon. Simulation results show the proposed platoon formation controller achieves safe, stable and rapid platoon formation than the traditional MOF-based formation controller which does not consider the vehicle dynamics. [ABSTRACT FROM AUTHOR]

This paper presents an integrated platoon control framework for heterogeneous vehicles on curved roads with varying slopes, aerodynamic drag, and wireless communication delays. First, a linear heterogeneous vehicle platoon model with decoupled longitudinal and lateral dynamics is built based on nonlinear feedback linearization and arc-length parametric transformation of an arbitrary curved road. The external disturbances are also considered, including the up-down road slopes, wind and equivalent time-delays caused by the wireless communication delay and discrete data in onboard sensors. Second, to achieve stable platoon control on a curved road, the platoon uses the state-feedback control method in the longitudinal direction while each vehicle tracks the centerline of the curved road to realize lateral control. Longitudinally, an $ H_\infty$ platoon controller is designed based on the Lyapunov-Krasovskii functional to ensure the inner-vehicle and string stability of the platoon, which suffers from parameter uncertainty, and external disturbances. Additionally, the $ \mathcal {L}_2$ string stability is defined to guarantee that the perturbations do not grow unbounded as they propagate through the platoon. Simulation results indicate that the proposed robust controller achieves proper platoon intervehicle spacing in both the longitudinal and lateral directions. [ABSTRACT FROM AUTHOR]

• A new time-domain-based energy-oriented spacing policy is proposed. • Discrete-time vehicle platoon system integrating communication delay and disturbance is provided. • Less conservative discrete robust platoon control methodology is developed. • L 2 -based string stability and its criterion of the discrete platoon are given. This paper presents a discrete control framework for a homogeneous vehicle platoon, which can minimize the energy consumption of each vehicle while ensuring the platoon string stability under external interference and communication delay. First, a novel variable spacing strategy named as the energy-oriented spacing policy is proposed by comparing the geometry relationship of each vehicle which drives at energy-optimal speed and the ideal speed under the constant spacing policy. Then, based on the energy-oriented spacing policy, the dynamics of a homogeneous discrete vehicle platoon composed of several pure electric vehicles are built, including the communication delay and external disturbance. Second, a discrete robust platoon controller that can reduce the conservatism of the control system is designed based on the Lyapunov-Krasovskii theorem and H ∞ method, which drives each vehicle at their energy-optimal speed while ensuring the string stability of platoon under communication delays and interferences. Third, the L 2 -based string stability of the discrete platoon is defined, and its string-stable criterion is given under communication delays and external disturbances. Simulation results indicate that the proposed energy-oriented spacing policy and the discrete controller can enable efficient driving of each vehicle while ensuring the platoon string stability. The energy consumption of the whole platoon is, respectively, reduced by 7.3% and 5.7% compared to the vehicle platoon controllers with constant spacing policy and constant time headway policy. [ABSTRACT FROM AUTHOR]

In this paper, we consider the boundary integral equation (BIE) methods for solving the exterior Neumann boundary value problems of elastic and thermoelastic waves in three dimensions based on the Fredholm integral equations of the first kind. The innovative contribution of this work lies in the proposal of the new regularized formulations for the hyper-singular boundary integral operators (BIO) associated with the time-harmonic elastic and thermoelastic wave equations. With the help of the new regularized formulations, we only need to compute the integrals with weak singularities at most in the corresponding variational forms of the boundary integral equations. The accuracy of the regularized formulations is demonstrated through numerical examples using the Galerkin boundary element method (BEM). [ABSTRACT FROM AUTHOR]

Abstract In the finite element and boundary element coupling method, the Stekhlov–Poincaré mapping is often adopted at the coupling boundary, i.e., the unknown Neumann data are represented by the unknown Dirichlet data on the same boundary. This coupling method (either by a convolution integral, or by a Fourier series) is referred as the conventional method. We propose an alternative method, where the unknown Dirichlet data at the boundary are represented by the unknown solution value on an interior curve or surface, i.e., a Dirichlet-to-Dirichlet (D-to-D) mapping is employed instead of a Dirichlet-to-Neumann (D-to-N) mapping. The convergence of the method is shown to be of optimal order. 2D and 3D numerical experiments are performed to demonstrate the accuracy of the proposed method, comparing to the two conventional D-to-N coupling methods. [ABSTRACT FROM AUTHOR]

Alkali-activated aluminosilicate cements, as a sustainable and high-performance class of cementitious materials, can benefit from the development of admixtures that can enhance various aspects of their performance. Alkali activation generally occurs at a faster pace than the hydration of Portland cement (PC). In this investigation, citric acid was evaluated as an admixture for controlling the hydration kinetics, enhancing the fresh-mix rheology and delaying the setting of alkali aluminosilicate cement (AAC) without compromising its long-term strength. The obtained experimental results showed that the use of 3 wt% citric acid reduced the heat of hydration, improved the fresh-mix rheology and increased the hardened material compressive strength of the AAC. The results demonstrate the merits of using citric acid as an effective admixture in alkali-activated cement to make it more compatible with the construction practices established for PC. [ABSTRACT FROM AUTHOR]

This paper is concerned with a Galerkin boundary element method solving the two dimensional exterior elastic wave scattering problem. The original problem is first reduced to the so-called Burton–Miller [1] boundary integral formulation, and essential mathematical features of its variational form are discussed. In numerical implementations, a newly-derived and analytically accurate regularization formula [2] is employed for the numerical evaluation of hyper-singular boundary integral operator. A new computational approach is employed based on the series expansions of Hankel functions for the computation of weakly-singular boundary integral operators during the reduction of corresponding Galerkin equations into a discrete linear system. The effectiveness of proposed numerical methods is demonstrated using several numerical examples. [ABSTRACT FROM AUTHOR]

Noninvasive and accurate assessment of driving fatigue in relation to brain activity during long-term driving can contribute to traffic safety and accident prevention. This study evaluated functional connectivity (FC) in relevant brain regions. Synergistic mechanisms in different brain regions were detected by a novel simulator, which combined semi-immersive virtual reality technology and functional near-infrared spectroscopy. Each subject was instructed to complete driving tasks coupled with a mental calculation task. Wavelet coherence (WCO) and wavelet phase coherence (WPCO) were calculated and assessed in frequency intervals (I) 0.6–2 and (II) 0.145–0.6 Hz as global connectivity measures; (III) 0.052–0.145, (IV) 0.021–0.052, (V) 0.0095–0.021 and (VI) 0.005–0.0095 Hz as FC. WCO and WPCO revealed the strength and synchronization of cerebral connectivity, respectively. Significantly low WCO levels were found in intervals I and III in prefrontal cortex (PFC) and IV in motor cortex (MC) at the end of the driving task. Furthermore, significantly low WPCO were found in intervals I, and III in PFC and interval IV in MC. Experimental findings suggested that progressive mental fatigue adversely influences the cognitive function in the PFC and the cooperative mechanism between the PFC and MC. [ABSTRACT FROM AUTHOR]

A true random number generator (TRNG) is a fundamental security primitive. Recently, the semiconductor superlattice (SSL) has been investigated as an ideal physical entropy source with high speed. It shows multi-degree freedom nonlinearity based on the effects of quantum mechanics. However, there is still a lack of systematic evaluation schemes for SSL. In this study, a chaotic assessment model for SSL is proposed. Chaotic characteristic assessment and nonlinear dynamics estimation are carried out using the model. Furthermore, a set of entropy estimation procedures are introduced to evaluate the uncertainty of the SSL. The estimation results demonstrate that SSL is chaotic, highly complex, and nonlinear. SSL shows stable performance and has an entropy rate greater than 50% with 8 sample bits. Moreover, the throughput of the assessment prototype reaches 300 Mbit/s. In brief, SSL is an excellent physical entropy source for high-quality and high-speed TRNG. [ABSTRACT FROM AUTHOR]

This work proposes an accurate hyper-singular boundary integral equation method for dynamic poroelastic problems with Neumann boundary condition in three dimensions and both the direct and indirect methods are adopted to construct combined boundary integral equations. The strongly-singular and hyper-singular integral operators are reformulated into compositions of weakly-singular integral operators and tangential-derivative operators, which allow us to prove the jump relations associated with the poroelastic layer potentials and boundary integral operators in a simple manner. Relying on both the investigated spectral properties of the strongly-singular operators, which indicate that the corresponding eigenvalues accumulate at three points whose values are only dependent on two Lamé constants, and the spectral properties of the Calderón relations of the poroelasticity, we propose low-GMRES-iteration regularized integral equations. Numerical examples are presented to demonstrate the accuracy and efficiency of the proposed methodology by means of a Chebyshev-based rectangular-polar solver. • Regularized integral equations for 3D poroelastic problem. • Spectral properties of poroelastic boundary integral operators. • Accurate reformulations for singular integrals. • High-order numerical implementation. [ABSTRACT FROM AUTHOR]

A series of batch cultures were conducted to investigate the effects of oleic acid (OA) on in vitro ruminal dry matter degradability (IVDMD), gas production, methane (CH4) and hydrogen (H2) production, and proportion of fatty acids. Rumen fluid was collected from fistulated goats, diluted with incubation buffer, and then incubated with 500 mg Leymus chinensis meal supplemented with different amounts of OA (0, 20, 40, and 60 mg for the CON, OA20, OA40 and OA60 groups, respectively). Incubation was carried out anaerobically at 39°C for 48 h, and the samples were taken at 12, 24 and 48 h and subjected to laboratory analysis. Supplementation of OA decreased IVDMD, the cumulative gas production, theoretical maximum of gas production and CH4 production, but increased H2 production. However, no effect was observed on any parameters of rumen fermentation (pH, ammonia, production of acetate, propionate and butyrate and total volatile fatty acid production). The concentrations of some beneficial fatty acids, such as cis monounsaturated fatty acids and conjugated linoleic acid (CLA) were higher (P < 0.05) from OA groups than those from the control group at 12 h incubation. In summary, these results suggest that the OA supplementation in diet can reduce methane production and increase the amount of some beneficial fatty acids in vitro. [ABSTRACT FROM AUTHOR]

Theeffectsof linoleicacid (LA)supplementationoninvitrodry matterdisappearance(DMD),gasproduction, methane and hydrogen gas production, ruminal fermentation characteristics, and fatty acid (FA) profiles in fermentation fluidwere investigated in vitro. Rumen fluidwas collected from four ruminally cannulated goats, diluted with incubation buffer, and then incubated with 500mg Leymus chinensis meal supplemented with differentamounts ofLA(0,20, 40, and60mg for the control,LA20,LA40, andLA60groups, respectively). In vitro rumen incubation was anaerobically carried out in 130-mL sealed fermentation bottles at 39°C for 48 h, and samples were collected at three time points (12, 24, and 48 h) for analysis. Supplementation ofLAreduced DMD(P<0.05), thecumulativegasproduction, theoretical maximal gas production andmethane production (P<0.05), whilst increased the hydrogen gas production. In addition,LAaddition to substrate had no negative effects on ruminal fermentation parameters (pH,NH3, and VFA).The concentration of total polyunsaturated fatty acid (PUFA) and conjugated linoleic acid (CLA) were higher for LA groups than for control during the whole incubation process. These results indicate that LA supplementation in substrate reduces gas and methane production, and increases the amounts of some beneficial fatty acids in fermentation liquid in vitro. [ABSTRACT FROM AUTHOR]

We present an iterative method to compute the Maxwell’s transmission eigenvalue problem which has importance in non-destructive testing of anisotropic materials. The transmission eigenvalue problem is first written as a quad-curl eigenvalue problem. Then we show that the real transmission eigenvalues are the roots of a nonlinear function whose value is the generalized eigenvalue of a related self-adjoint quad-curl eigenvalue problem which is computed using a mixed finite element method. A secant method is used to compute the roots of the nonlinear function. Numerical examples are presented to validate the method. Moreover, the method is employed to study the dependence of the transmission eigenvalue on the anisotropy and to reconstruct the index of refraction of an inhomogeneous medium. [ABSTRACT FROM AUTHOR]

Abstract: Ideal magnetohydrodynamic (MHD) equations consist of a set of nonlinear hyperbolic conservation laws, with a divergence-free constraint on the magnetic field. Neglecting this constraint in the design of computational methods may lead to numerical instability or nonphysical features in solutions. In our recent work [F. Li, L. Xu, S. Yakovlev, Central discontinuous Galerkin methods for ideal MHD equations with the exactly divergence-free magnetic field, Journal of Computational Physics 230 (2011) 4828–4847], second and third order exactly divergence-free central discontinuous Galerkin methods were proposed for ideal MHD equations. In this paper, we further develop such methods with higher order accuracy. The novelty here is that the well-established H(div)-conforming finite element spaces are used in the constrained transport type framework, and the magnetic induction equations are extensively explored in order to extract sufficient information to uniquely reconstruct an exactly divergence-free magnetic field. The overall algorithm is local, and it can be of arbitrary order of accuracy. Numerical examples are presented to demonstrate the performance of the proposed methods especially when they are fourth order accurate. [Copyright &y& Elsevier]

Abstract: In this paper, we reduce the classical two-dimensional transmission problem in acoustic scattering to a system of coupled boundary integral equations (BIEs), and consider the weak formulation of the resulting equations. Uniqueness and existence results for the weak solution of corresponding variational equations are established. In contrast to the coupled system in Costabel and Stephan (1985) , we need to take into account exceptional frequencies to obtain the unique solvability. Boundary element methods (BEM) based on both the standard and a two-level fast multipole Galerkin schemes are employed to compute the solution of the variational equation. Numerical results are presented to verify the efficiency and accuracy of the numerical methods. [Copyright &y& Elsevier]

Abstract: In this paper, central discontinuous Galerkin methods are developed for solving ideal magnetohydrodynamic (MHD) equations. The methods are based on the original central discontinuous Galerkin methods designed for hyperbolic conservation laws on overlapping meshes, and use different discretization for magnetic induction equations. The resulting schemes carry many features of standard central discontinuous Galerkin methods such as high order accuracy and being free of exact or approximate Riemann solvers. And more importantly, the numerical magnetic field is exactly divergence-free. Such property, desired in reliable simulations of MHD equations, is achieved by first approximating the normal component of the magnetic field through discretizing induction equations on the mesh skeleton, namely, the element interfaces. And then it is followed by an element-by-element divergence-free reconstruction with the matching accuracy. Numerical examples are presented to demonstrate the high order accuracy and the robustness of the schemes. [Copyright &y& Elsevier]

Abstract: We present an accurate and efficient numerical model for the simulation of fully nonlinear (non-breaking), three-dimensional surface water waves on infinite or finite depth. As an extension of the work of Craig and Sulem , the numerical method is based on the reduction of the problem to a lower-dimensional Hamiltonian system involving surface quantities alone. This is accomplished by introducing the Dirichlet–Neumann operator which is described in terms of its Taylor series expansion in homogeneous powers of the surface elevation. Each term in this Taylor series can be computed efficiently using the fast Fourier transform. An important contribution of this paper is the development and implementation of a symplectic implicit scheme for the time integration of the Hamiltonian equations of motion, as well as detailed numerical tests on the convergence of the Dirichlet–Neumann operator. The performance of the model is illustrated by simulating the long-time evolution of two-dimensional steadily progressing waves, as well as the development of three-dimensional (short-crested) nonlinear waves, both in deep and shallow water. [Copyright &y& Elsevier]

Objective: The early identification and diagnosis of transplant-associated thrombotic microangiopathy (TA-TMA) are essential yet difficult in patients underwent hematopoietic stem cell transplantation (HSCT). To develop an evidence-based, nurse-leading early warning model for TA-TMA, and implement the healthcare quality review and improvement project. Methods: This study was a mixed-methods, before-and-after study. The early warning model was developed based on quality evidence from literature search. The healthcare quality review and improvement project mainly included baseline investigation of nurse, improvement action and effectiveness evaluation. The awareness and knowledge of early parameter of TA-TMA among nurses and the prognosis of patients underwent HSCT were compared before and after the improvement. Results: A total of 1 guideline, 1 evidence synthesis, 4 expert consensuses, 10 literature reviews, 2 diagnostic studies, and 9 case series were included in the best evidence. The early warning model including warning period, high-risk characteristics and early manifestation of TA-TMA was developed. The improvement action, including staff training and assessment, suspected TA-TMA identification and patient education, was implemented. The awareness and knowledge rate of early parameter of TA-TMA among nurses significantly improved after improvement action (100% vs. 26.7%, P < 0.001). The incidence of TA-TMA was similar among patients underwent HSCT before and after improvement action (2.8% vs. 1.2%, P = 0.643), while no fall event occurred after improvement action (0 vs. 1.2%, P < 0.001). Conclusion: The evidence-based early warning model and healthcare quality improvement project could enhance the awareness and knowledge of TA-TMA among healthcare providers and might improve the prognosis of patients diagnosed with TA-TMA. [ABSTRACT FROM AUTHOR]

An implicit Galerkin meshfree scheme based on the element-free Galerkin (EFG) and the backward Euler methods is analyzed for general second-order parabolic problems. The penalty method is used to impose Dirichlet boundary conditions, and a priori approximation error has been derived to confirm its validity. The existence and uniqueness of the weak solution for the penalized parabolic problems under homogeneous mixed boundary conditions are proved, offering an insight for numerical discretizations. With an orthogonal projection being defined, the continuous error bounds with the penalty factor for the semi-discrete approximation are obtained, and meanwhile, the discrete error bounds with the penalty factor for the fully discrete approximation are also achieved, which provide a theoretical explanation for the value of a reasonable penalty factor. Finally, numerical examples are conducted to verify the theoretical results. [ABSTRACT FROM AUTHOR]

In this work, we investigate numerical solutions of the two-dimensional shallow water wave using a fully nonlinear Green-Naghdi model with an improved dispersive effect. For numerics, the Green-Naghdi model is rewritten into a formulation coupling a pseudo-conservative system and a set of pseudo-elliptic equations. Since the pseudo-conservative system is no longer hyperbolic and its Riemann problem can only be approximately solved, we consider the utilization of the central discontinuous Galerkin method, which possesses an important feature of the needlessness of Riemann solvers. Meanwhile, the stationary elliptic part will be solved using the finite element method. Both the well-balanced and the positivity-preserving features, which are highly desirable in the simulation of the shallow water wave, will be embedded into the proposed numerical scheme. The accuracy and efficiency of the numerical model and method will be illustrated through numerical tests. • A 2D modified Green-Naghdi model with enhanced dispersive property is derived. • A 2D numerical model is presented to reformulate the modified Green-Naghdi model. • A positivity-preserving well balanced CDG-FE method is presented for the model. • The presented method is a high order Galerkin scheme and free of Riemann solver. • A wide range of numerical tests demonstrate the numerical model and scheme. [ABSTRACT FROM AUTHOR]

A free-running Fe:ZnSe laser is demonstrated under the pump of a single-shot 2.94 μm Er:YAG laser along the cavity axis at liquid nitrogen temperature of 77 K. At the incident pump energy of 1.47 J, a maximum single pulse energy of 253.7 mJ is obtained with a minimum pulse duration of 92.4 μs, corresponding to a slope efficiency of 16.2%. The central wavelength and the full width at half maximum (FWHM) are 3944.7 and 68.4 nm, respectively. [ABSTRACT FROM AUTHOR]

In this paper, we consider a cavity reconstruction problem for the interior acoustic scattering from limited-aperture measurements. To recover the shape of the cavity, the Bayesian inference technique is applied with the information of posterior distribution of the unknown object being explored in terms of the measured data. The posterior distribution provides us with sufficient knowledge about the unknowns, and therefore it can be used to give the corresponding estimation. We discuss the well-posedness of the posterior distribution in the sense of the Hellinger metric and use the preconditioned Crank–Nicolson (pCN) sampling technique to generate the posterior samples. Numerical examples show the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

The accurate information of sideslip angle (SA) and tire cornering stiffness (TCS) is essential for advanced chassis control systems. However, SA and TCS cannot be directly measured by in-vehicle sensors. Thus, it is a hot topic to estimate SA and TCS with only in-vehicle sensors by an effective estimation method. In this article, we propose a novel fuzzy adaptive robust cubature Kalman filter (FARCKF) to accurately estimate SA and TCS. The model parameters of the FARCKF are dynamically updated using recursive least squares. A Takagi–Sugeno fuzzy system is developed to dynamically adjust the process noise parameter in the FARCKF. Finally, the performance of FARCKF is demonstrated via both simulation and experimental tests. The test results indicate that the estimation accuracy of SA and TCS is higher than that of the existing methods. Specifically, the estimation accuracy of SA is at least improved by more than 48%, while the estimators of TCS are closer to the reference values. [ABSTRACT FROM AUTHOR]

Inverse problems are more challenging when only partial data are available in general. In this paper, we propose a two-step approach combining the extended sampling method and the ensemble Kalman filter to reconstruct an elastic rigid obstacle using partial data. In the first step, the approximate location of the unknown obstacle is obtained by the extended sampling method. In the second step, the ensemble Kalman filter is employed to reconstruct the shape. The location obtained in the first step guides the construction of the initial particles of the ensemble Kalman filter, which is critical to the performance of the second step. Both steps are based on the same physical model and use the same scattering data. Numerical examples are shown to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Tumor heterogeneity and its drivers impair tumor progression and cancer therapy. Single‐cell RNA sequencing is used to investigate the heterogeneity of tumor ecosystems. However, most methods of scRNA‐seq amplify the termini of polyadenylated transcripts, making it challenging to perform total RNA analysis and somatic mutation analysis.Therefore, a high‐throughput and high‐sensitivity method called snHH‐seq is developed, which combines random primers and a preindex strategy in the droplet microfluidic platform. This innovative method allows for the detection of total RNA in single nuclei from clinically frozen samples. A robust pipeline to facilitate the analysis of full‐length RNA‐seq data is also established. snHH‐seq is applied to more than 730 000 single nuclei from 32 patients with various tumor types. The pan‐cancer study enables it to comprehensively profile data on the tumor transcriptome, including expression levels, mutations, splicing patterns, clone dynamics, etc. New malignant cell subclusters and exploring their specific function across cancers are identified. Furthermore, the malignant status of epithelial cells is investigated among different cancer types with respect to mutation and splicing patterns. The ability to detect full‐length RNA at the single‐nucleus level provides a powerful tool for studying complex biological systems and has broad implications for understanding tumor pathology. [ABSTRACT FROM AUTHOR]

Objective To investigate the levels and clinical significance of serum microRNA (miR)-651 and miR-630 in patients with cervical cancer. Methods From June 2017 to May 2020, 108 cervical cancer patients accepted by our hospital were collected as the cervical cancer group. Meantime, 100 cervical intraepithelial neoplasia (CIN) patients treated in our hospital were regarded as the CIN group, and 110 healthy individuals who underwent physical examination were regarded as the control group. Real-time fluorescence quantitative PCR (qRT-PCR) was applied to detect serum levels of miR-651 and miR-630, while analyzing the relationship between serum miR-651 and miR-630 as well as clinical features and prognosis of patients. Results The serum levels of miR-651 and miR-630 in the cervical cancer group and CIN group were obviously lower than those in the control group (P<0.05), while the serum levels of miR-651 and miR-630 in the cervical cancer group were obviously lower than those in the CIN group (P < 0.05). The expression levels of serum miR-651 and miR-630 were positively correlated (r = 0.542, P < 0.05). The serum levels of miR-651 and miR-630 were related to HPV infection, differentiation, lymph node metastasis, and FIGO staging (P < 0.05). The overall survival rate of patients with low levels of miR-651 and miR-630 was lower than that of patients with high levels. Cox regression analysis showed that, HPV infection, degree of differentiation, lymph node metastasis, FIGO staging, miR-651, and miR-630 were all influencing factors for the prognosis of cervical cancer patients (P < 0.05). Conclusion The serum levels of miR-651 and miR-630 in cervical cancer patients decrease, which are related to HPV infection, differentiation, lymph node metastasis, FIGO staging, and prognosis. [ABSTRACT FROM AUTHOR]

Epidemiological cohort studies investigating the association between vasectomy and prostate cancer risk have yielded inconsistent results. The aim of the present meta-analysis is to update the evidence on the association between vasectomy and prostate cancer. A comprehensively literature search of relevant studies was performed in December 2019 using PubMed. A DerSimonian and Laird random-effects model was used to calculate the summary relative risk (RR) and its 95% confidence interval (CI). A total of 15 eligible cohort studies (16 data sets) with more than four million of participants were eventually included in this meta-analysis. There was a statistically significant higher risk of prostate cancer among men who underwent vasectomy (RR: 1.09, 95% CI: 1.04–1.13) with obvious heterogeneity among included studies (P < 0.001, I 2 = 64.2%). Vasectomy was also associated with the risk of advanced prostate cancer (RR: 1.07, 95% CI: 1.02–1.13), which is less likely to be affected from detection bias. In conclusion, findings from this meta-analysis of prospective studies indicate that vasectomy may be positively associated with the risk of prostate cancer. Further large prospective studies with long follow-up are warranted to verify the findings from this meta-analysis. In addition, the potential underlying molecular mechanism needed further exploration with in vitro and animal studies. [ABSTRACT FROM AUTHOR]

Lightweight electric vehicles (LEVs) possess great advantages in the viewpoint of fuel consumption, environment protection and traffic mobility. However, due to the drastic reduction of vehicle weights and body size, the effects of payload parameter variation in LEV control and estimation system become much more pronounced and have to be systematically analysed. This paper proposes a novel payload parameter sensitivity analysis to provide quantitative insight into the sensitivity of payload parameter on the LEV system responses and state estimation. The analysis-oriented LEV dynamic model considering payload parameter variations is developed. Then, the trajectory sensitivity index of the influential parameters is defined and derived with the perturbation approach, the median method is used to improve the calculation accuracy for the trajectory sensitivity of payload parameter. Finally, the extended Kalman filter is designed to show the effect and importance of the sensitive payload parameters on the observation accuracy, the payload parameter variations along with fundamental state estimation such as vehicle sideslip angle, longitudinal velocity and vehicle roll angle are analysed. Simulation results with Matlab/Simulink-Carsim® show that the proposed method can accurately describe the relationship between the vehicle payload parameters and system state estimation, which is helpful to design and evaluate LEV controller and observer performances. [ABSTRACT FROM AUTHOR]

In this paper, we study a hybridizable discontinuous Galerkin (HDG) method for the Maxwell operator. The only global unknowns are defined on the inter-element boundaries, and the numerical solutions are obtained by using discontinuous polynomial approximations. The error analysis is based on a mixed curl-curl formulation for the Maxwell equations. Theoretical results are obtained under a more general regularity requirement. In particular for the low regularity case, special treatment is applied to approximate data on the boundary. The HDG method is shown to be stable and convergence in an optimal order for both high and low regularity cases. Numerical experiments with both smooth and singular analytical solutions are performed to verify the theoretical results. [ABSTRACT FROM AUTHOR]

Background:Postoperative cognitive dysfunction (POCD) is common following cardiac and non-cardiac surgery, but the pathogenic mechanisms remain unknown. Many studies suggest that an inflammatory response is a key contributor to POCD. The current meta-analysis shows that the levels of peripheral inflammatory markers are associated with POCD. Methods:An online search was performed to identify peer-reviewed studies without language restriction that measured peripheral inflammatory markers of patients with and without POCD, using PubMed, ScienceDirect, SinoMed and the National Knowledge Infrastructure database. Extracted data were analyzed with STATA (version 12).The standardized mean difference (SMD) and the 95% confidence interval (95%CI) were calculated for each outcome using a random effect model. Tests of heterogeneity assessment of bias, and meta-regression were performed in the meta-analysis. Results:A total of 13 studies that measured the concentrations of peripheral inflammatory markers were included. The current meta-analysis found significantly higher concentrations of S-100β(SMD[95%CI]) (1.377 [0.423, 2.331], p-value < 0.001, N [POCD/non-POCD] =178/391, 7 studies), and interleukin(IL)-6 (SMD[95%CI]) (1.614 [0.603,2.624], p-value < 0.001, N[POCD/non-POCD] = 91/99, 5 studies), but not of neuron specific enolase, interleukin-1β, or tumor necrosis factor-α , in POCD compared with patients without POCD. In meta-regression analyses, a significant positive association was found between the SMD and the preoperative interleukin-6 peripheral blood concentration in patients with POCD (Coef.= 0.0587, p-value=0.038, 5 studies). Conclusions:This study shows that POCD is indeed correlated with the concentrations of peripheral inflammatory markers, particularly interleukin-6 and S-100β. [ABSTRACT FROM AUTHOR]

Blockchain technology affords data integrity protection and building trust mechanisms in transactions for distributed networks, and, therefore, is seen as a promising revolutionary information technology. At the same time, the ongoing breakthrough in quantum computation technology contributes toward large-scale quantum computers, which might attack classic cryptography, seriously threatening the classic cryptography security currently employed in the blockchain. As a better alternative, a quantum blockchain has high expectations of being immune to quantum computing attacks perpetrated by quantum adversaries. Although several works have been presented, the problems of impracticality and inefficiency in quantum blockchain systems remain prominent and need to be addressed. First, this paper develops a quantum-secure blockchain (QSB) scheme by introducing a consensus mechanism—quantum proof of authority (QPoA) and an identity-based quantum signature (IQS)—wherein QPoA is used for new block generation and IQS is used for transaction signing and verification. Second, QPoA is developed by adopting a quantum voting protocol to achieve secure and efficient decentralization for the blockchain system, and a quantum random number generator (QRNG) is deployed for randomized leader node election to protect the blockchain system from centralized attacks like distributed denial of service (DDoS). Compared to previous work, our scheme is more practical and efficient without sacrificing security, greatly contributing to better addressing the challenges in the quantum era. Extensive security analysis demonstrates that our scheme provides better protection against quantum computing attacks than classic blockchains. Overall, our scheme presents a feasible solution for blockchain systems against quantum computing attacks through a quantum strategy, contributing toward quantum-secured blockchain in the quantum era. [ABSTRACT FROM AUTHOR]

This paper is concerned with a variational approach solving the two-dimensional acoustic transmission problems. The original problem is reduced to an equivalent nonlocal boundary value problem by introducing an exact Dirichlet-to-Neumann (DtN) mapping in terms of Fourier expansion series on an artificial boundary. Uniqueness and existence of solutions in appropriate Sobolev spaces are established for the corresponding variational problem and its modification due to the truncation of DtN mapping. A priori error estimates containing the effects of both element meshsize and truncation order of series for the finite element approximation are derived. Numerical experiments are also presented to illustrate the efficiency and accuracy of the numerical scheme. [ABSTRACT FROM AUTHOR]

The accurate knowledge of tire–road friction coefficient (TRFC) contributes to the optimization of driver maneuvers for further improving the safety of intelligent vehicles. The performance of the existing estimation methods would decline when a vehicle performs complex driving maneuvers. In addition, the mass parameter mismatch also deteriorates the estimation accuracy of TRFC. To address these problems, in this article, an integrated scheme for TRFC estimation is proposed by combining a strong tracking unscented Kalman filter and an interactive multiple model unscented Kalman filter. Real-time experiments are implemented on a mass-produced vehicle to demonstrate the feasibility and effectiveness of the proposed method. The results show that the proposed approach has better estimation accuracy than the existing ones under various driving scenarios. [ABSTRACT FROM AUTHOR]

Parameter calibration is critical for self-localization based on dead reckoning in the control of intelligent vehicles such as autonomous driving. Most traditional calibration methods for robotics control based on dead reckoning rely on data collection with specially designed paths. For the calibration of parameters in the control of intelligent vehicles, the design of such paths is considered impossible due to the complexity of road conditions. To solve this problem, an optimization-based dead reckoning calibration scheme is introduced in this research using the differential global positioning system to obtain the actual positions of the intelligent vehicle. In this scheme, the difference between the positions obtained through dead reckoning and the positions obtained through the differential global positioning system is selected as the optimization objective function to be minimized. An adaptive quantum-inspired evolutionary algorithm is developed to improve the quality and efficiency of optimization. Experiments with an intelligent vehicle were also conducted to demonstrate the effectiveness of the developed calibration scheme. In addition, the newly introduced adaptive quantum-inspired evolutionary algorithm is compared with the classic genetic algorithm and the classic quantum-inspired evolutionary algorithm using eight benchmark test functions considering computation quality and efficiency. [ABSTRACT FROM AUTHOR]

Peanut sprouts contain abundant bioactive substances including resveratrol and other natural polyphenols, which have strong antioxidant activity. Herein, we describe the formulation of peanut sprout yogurt, which combines the antioxidant activity of a fermented product with the added activity afforded by peanut sprouts. A fuzzy mathematical model was developed for the sensory evaluation of the peanut sprout yogurt based on three indexes: the color, taste, and texture of yogurt. Using the fuzzy mathematical model, the optimal parameters of peanut sprout yogurt were 0.4% lactic acid bacteria, 8% white sugar, and 2% peanut sprout freeze‐dried powder. Subsequently, the antioxidant activity of the yogurt was evaluated by 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2, 2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) radical scavenging activity assays. Peanut sprout yogurt had higher antioxidant activity (25.07 ± 0.05%, DPPH; 24.75 ± 0.01%, ABTS) as compared to plain yogurt (17.10 ± 0.05%, DPPH; 17.03 ± 0.02%, ABTS). Interestingly, the Colony‐Forming Unit (CFU) of lactic acid bacteria in plain yogurt versus peanut sprout yogurt differed, 1.9 × 109 CFU/g and 3.6 × 109 CFU/g, respectively. The two yogurts also differed in protein, fat, carbohydrate, and caloric content with peanut sprout yogurt determined as 6.3 g/100 g, 4.2 g/100 g, 18.0 g/100 g, and 559.0 kJ/100 g, respectively, versus plain yogurt determined as 3.3 g/100 g, 3.9 g/100 g, 13.0 g/100 g, and 422.0 kJ/100 g, respectively. Novelty impact statement: Yogurt containing peanut sprouts had higher content levels of lactic acid bacteria.The addition of peanut sprout increased the antioxidant activity of yogurt.Optimum concentration of peanut sprout in the yoghurt was 2%. [ABSTRACT FROM AUTHOR]

In this paper, we propose and analyze a fully discrete finite element projection method for the magnetohydrodynamic (MHD) equations. A modified Crank–Nicolson method and the Galerkin finite element method are used to discretize the model in time and space, respectively, and appropriate semi-implicit treatments are applied to the fluid convection term and two coupling terms. These semi-implicit approximations result in a linear system with variable coefficients for which the unique solvability can be proved theoretically. In addition, we use a second-order decoupling projection method of the Van Kan type [Van Kan, SIAM J. Sci. Statist. Comput.7 (1986) 870–891] in the Stokes solver, which computes the intermediate velocity field based on the gradient of the pressure from the previous time level, and enforces the incompressibility constraint via the Helmholtz decomposition of the intermediate velocity field. The energy stability of the scheme is theoretically proved, in which the decoupled Stokes solver needs to be analyzed in details. Error estimates are proved in the discrete L∞(0, T; L2) norm for the proposed decoupled finite element projection scheme. Numerical examples are provided to illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To describe the early surgical repair of iatrogenic ureterovaginal fistula (UVF) secondary to gynecologic surgery, and evaluate the efficacy and feasibility of early surgical intervention. Methods: Data were retrospectively reviewed for 52 patients with iatrogenic UVF who underwent early surgical repair between January 1996 and January 2011 at the Sir Run Run Shaw Hospital, Hangzhou, China. Preoperative patient characteristics and postoperative endpoints, including type of index procedure, repair technique, operative time, perioperative complications, and postoperative follow-up data were assessed. Results: All early surgical repairs were uneventful. The mean time from diagnosis to surgery was 15.7days (range, 14–21days). The mean operative time was 73.4min (range, 51–110min) for ureteroneocystostomy, and 104min (range, 91.5–153min) for Boari flap procedure. The mean estimated blood loss was 57.8mL (range, 35–80mL). No major intraoperative complications occurred, although 5 patients had postoperative surgical site infections. Forty-three patients were followed for a mean of 18.4months (range, 10.5–24.0months). Ureteral stricture with asymptomatic hydronephrosis occurred in 2 (4.7%) patients. Ipsilateral renal function was preserved in all patients. Conclusion: Early surgical repair of UVF secondary to gynecologic surgery was safe and effective, and preserved ipsilateral renal function. [Copyright &y& Elsevier]

In this paper, a fully discrete numerical scheme is proposed and analyzed for the harmonic mapping flow, with the fourth order spatial accuracy and higher than third order temporal accuracy. The fourth order spatial accuracy is realized via a long stencil finite difference, and the boundary extrapolation is implemented by making use of higher order Taylor expansion. Meanwhile, the high order (third or fourth order) temporal accuracy is based on a semi-implicit algorithm, which uses a combination of explicit Adams–Bashforth extrapolation for the nonlinear terms and implicit Adams–Moulton interpolation for the viscous diffusion term, with the corresponding integration formula coefficients. Both the consistency, linearized stability analysis and optimal rate convergence estimate (in the ℓ ∞ (0 , T ; ℓ 2) ∩ ℓ 2 (0 , T ; H h 1) norm) are provided. A few numerical examples are also presented in this article. [ABSTRACT FROM AUTHOR]

Abstract: A novel and simple fluorescent chemosensor based on rhodamine was designed and synthesized to detect Hg2+ with high selectivity. The structure of chemosensor 1 was characterized by IR, 1H NMR, and HRMS spectroscopies. Chemosensor 1 exhibited distinct fluorescent and colorimetric changes toward Hg2+ in an ethanol/water (80/20, v/v) solution, which resulted in the formation of 1/Hg2+ complex with the Hg2+-induced ring opening of the spirolactam ring in rhodamine. The reversibility of chemosensor 1 was verified through its spectral response toward Hg2+ ions and TBAI (tetrabutylammonium iodide) titration experiments. [Copyright &y& Elsevier]

In this article, a variational formulation for the transmission problem of the fluid-bone interaction is formulated. The formulation is based on a modified Biot system of equations for the cancellous bone together with a boundary integral equation formulation of the pressure in the water. Existence and uniqueness for the weak solution of the interaction problem are established in appropriate Sobolev spaces. [ABSTRACT FROM AUTHOR]