Search

Repairing skin wounds has always been challenging in clinical practice. The new skin tissue engineering scaffold provides innovative ways to address these challenges with a good chance of success because of its stable mechanical properties, biodegradability, and antibacterial properties. This paper presents the fabrication and evaluation of a three-dimensional composite scaffold made with sulfated silk fibroin, chitosan, and hydroxyapatite (SSF/CS/HAP). An electron microscope shows that the scaffold has an aperture of 15-20 μm, while an absorption performance test shows that its expansion index reaches 779%. The co-culture of L929 cells and the CCK-8 experiments demonstrated good cell compatibility and low scaffold cytotoxicity, respectively. Meanwhile, in vivo experiments demonstrate that rats with SSF/CS/HAP scaffold-treated neck wounds heal faster. In the wound skin tissue of the SSF/CS/HAP scaffold group, immunohistochemistry indicates a more rapid and mature development of hair follicles. This study successfully developed a novel skin tissue engineering scaffold material with high moisture retention, high tissue compatibility, and low cytotoxicity, demonstrating its ability to improve wound repair with promising potential for tissue engineering applications.

The main goal of this study is to propose a trajectory planning algorithm for the merging control of heterogeneous vehicular platoons. Merging control is essential for the application of vehicular platoons, by which vehicles can be coordinated to form a platoon in a lane. While most previous researches on merging control only considered the operation on straight roads and ramps. Few studies have investigated the merging operation on curve roads, which may hinder the application of platoons on general traffic environment. In this study, a trajectory planning algorithm is proposed for the merging control of heterogeneous vehicular platoons on curve roads with constant radius. The proposed algorithm consists of two stages for the operation of merging: the first stage is to align the vehicles in each lane to form a structure with a certain clearance; the second stage is to conduct a lane changing manoeuvre for each merging vehicle to form a platoon in a lane. In the proposed algorithm, the dynamic limits of speed and acceleration are considered. The distance of each vehicle can be guaranteed to avoid undesired collisions. Two simulations are carefully conducted for the merging control of heterogeneous vehicular platoons on a curve road to demonstrate the effectiveness of the proposed algorithm. The results of simulations indicate that the proposed algorithm is capable of the merging control of platoons on a curve road.

Few-shot learning for image classification comes up as a hot topic in computer vision, which aims at fast learning from a limited number of labeled images and generalize over the new tasks. In this paper, motivated by the idea of Fisher Score, we propose a Discriminative Local Descriptors Attention (DLDA) model that adaptively selects the representative local descriptors and does not introduce any additional parameters, while most of the existing local descriptors based methods utilize the neural networks that inevitably involve the tedious parameter tuning. Moreover, we modify the traditional $k$-NN classification model by adjusting the weights of the $k$ nearest neighbors according to their distances from the query point. Experiments on four benchmark datasets show that our method not only achieves higher accuracy compared with the state-of-art approaches for few-shot learning, but also possesses lower sensitivity to the choices of $k$.

We propose a model-data asymptotic-preserving neural network(MD-APNN) method to solve the nonlinear gray radiative transfer equations(GRTEs). The system is challenging to be simulated with both the traditional numerical schemes and the vanilla physics-informed neural networks(PINNs) due to the multiscale characteristics. Under the framework of PINNs, we employ a micro-macro decomposition technique to construct a new asymptotic-preserving(AP) loss function, which includes the residual of the governing equations in the micro-macro coupled form, the initial and boundary conditions with additional diffusion limit information, the conservation laws, and a few labeled data. A convergence analysis is performed for the proposed method, and a number of numerical examples are presented to illustrate the efficiency of MD-APNNs, and particularly, the importance of the AP property in the neural networks for the diffusion dominating problems. The numerical results indicate that MD-APNNs lead to a better performance than APNNs or pure data-driven networks in the simulation of the nonlinear non-stationary GRTEs.

In this paper, we propose a stochastic Gauss-Newton (SGN) algorithm to study the online principal component analysis (OPCA) problem, which is formulated by using the symmetric low-rank product (SLRP) model for dominant eigenspace calculation. Compared with existing OPCA solvers, SGN is of improved robustness with respect to the varying input data and algorithm parameters. In addition, turning to an evaluation of data stream based on approximated objective functions, we develop a new adaptive stepsize strategy for SGN (AdaSGN) which requires no priori knowledge of the input data, and numerically illustrate its comparable performance with SGN adopting the manaully-tuned diminishing stepsize. Without assuming the eigengap to be positive, we also establish the global and optimal convergence rate of SGN with the specified stepsize using the diffusion approximation theory., Comment: 31 pages, 11 figures

Hedyotis diffusa Willd. (HDW) is a traditional Chinese medicine used for the treatment of colorectal cancer. The aim of this study was to investigate the molecular mechanism of inhibitory effects of HDW on the growth of ovarian cancer cells. Treatment of ovarian cancer cells with increasing doses of HDW for 48 or 72 h resulted in a significant reduction in the viability and colony formation of cancer cells. In HDW-treated cancer cells, the cell cycle was blocked at the G0/G1 phase and cell apoptosis was 4- to 5-fold higher than that of control group. HDW treatment also markedly inhibited the migration and invasion of ovarian cancer cells. Mechanistically, the phosphorylation levels of AKT and ERK were down-regulated in HDW-treated ovarian cancer cells. Therefore, HDW is likely to become a promising therapeutic agent for ovarian cancer treatment.

The Calder��n formulas (i.e., the combination of single-layer and hyper-singular boundary integral operators) have been widely utilized in the process of constructing valid boundary integral equation systems which could possess highly favorable spectral properties. This work is devoted to studying the theoretical properties of elastodynamic Calder��n formulas which provide us with a solid basis for the design of fast boundary integral equation methods solving elastic wave problems defined on a close-surface or an open-surface in two dimensions. For the closed-surface case, it is proved that the Calder��n formula is a Fredholm operator of second-kind except for certain circumstances. Regarding to the open-surface case, we investigate weighted integral operators instead of the original integral operators which are resulted from dealing with edge singularities of potentials corresponding to the elastic scattering problems by open-surfaces, and show that the Calder��n formula is a compact perturbation of a bounded and invertible operator. To complete the proof, we need to use the well-posedness result of the elastic scattering problem, the analysis of the zero-frequency integral operators defined on the straight arc, the singularity decompositions of the kernels of integral operators, and a new representation formula of the hyper-singular operator. Moreover, it can be demonstrated that the accumulation point of the spectrum of the invertible operator is the same as that of the eigenvalues of the Calder��n formula in the closed-surface case.

In this paper, we propose and analyze a temporally second-order accurate, fully discrete finite element method for the magnetohydrodynamic (MHD) equations. A modified Crank--Nicolson method is used to discretize the model 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 decoupling projection method of the Van Kan type \cite{vankan1986} 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. Optimal-order convergence of $\mathcal{O} (\tau^2+h^{r+1})$ in the discrete $L^\infty(0,T;L^2)$ norm is proved for the proposed decoupled projection finite element scheme, where $\tau$ and $h$ are the time stepsize and spatial mesh size, respectively, and $r$ is the degree of the finite elements. Existing error estimates of second-order projection methods of the Van Kan type \cite{vankan1986} were only established in the discrete $L^2(0,T;L^2)$ norm for the Navier--Stokes equations. Numerical examples are provided to illustrate the theoretical results.

Background The therapeutic effects of adipose-derived mesenchymal stem cell (ADSC) transplantation have been demonstrated in several models of central nervous system (CNS) injury and are thought to involve the modulation of the inflammatory response. However, the exact underlying molecular mechanism is poorly understood. Activation of the Jagged1/Notch signaling pathway is thought to involve inflammatory and gliotic events in the CNS. Here, we elucidated the effect of ADSC transplantation on the inflammatory reaction after spinal cord injury (SCI) and the potential mechanism mediated by Jagged1/Notch signaling pathway suppression.Methods Using a mouse model of compression SCI, ADSCs and Jagged1 small interfering RNA (siRNA) were injected into the spinal cord. Locomotor function, spinal cord tissue morphology and the levels of various proteins and transcripts were compared between groups.Results ADSC treatment resulted in significant downregulation of proinflammatory mediator expression and reduced ionized calcium binding adapter molecule 1 (Iba1) and ED1 staining in the injured spinal cord, promoting the survival of neurons. These changes were accompanied by improved functional recovery. The augmentation of the Jagged1/Notch signaling pathway after SCI was suppressed by ADSC transplantation. The inhibition of the Jagged1/Notch signaling pathway by Jagged1 siRNA resulted in a decrease in SCI-induced proinflammatory cytokines as well as the activation of microglia. Furthermore, Jagged1 knockdown suppressed the phosphorylation of JAK/STAT3 following SCI.Conclusion The results of this study demonstrated that the therapeutic effects of ADSCs in SCI mice were partly due to Jagged1/notch signaling pathway inhibition and a subsequent reduction in JAK/STAT3 phosphorylation.

Garlic ( Allium sativum L.) is cultivated by extensive vegetative propagation, which may lead to germplasm degradation, the accumulation of various viruses, a low propagation coefficient, and high production costs. Tissue culture is the most effective method for the rapid propagation and germplasm enhancement of virus-free garlic. Here, we present a system for producing tissue culture garlic using inflorescences of Baodi garlic ‘Liu Ban Hong’ as explants. By optimizing the type and concentration of plant growth regulators, as many as 11 adventitious buds could be produced from one explant. The propagation coefficient of bulblets in vitro could reach 10.64 per explant after optimization of the culture approach and induction parameters. Additionally, tissue culture garlic was shown to achieve a certain virus elimination effect by ELISA. In this study, we present a complete system for producing virus-free Baodi garlic from explants. This system provides important technical support for eliminating viruses, increasing propagation efficiency, maintaining genetic stability, and improving the quality of garlic.

Hospital wastewater (HWW) is a source of estrogenic activity compounds in the environmental water system. Once released into water bodies, these compounds disrupt the aquatic ecological balance and even affect human health. On the basis of domestic and foreign literature, the potential chemicals and their properties, such as construction features and toxicological effects, in HWW were summarized and discussed. The advantages of ozone in removing target substances were also summarized.

Danyang Shen, Huan Wang, Qiming Zheng, Sheng Cheng, Liwei Xu, Mingchao Wang, Gong H Li, Li Q Xia Department of Urology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, People’s Republic of ChinaCorrespondence: Li Q Xia; Gong H LiDepartment of Urology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, People’s Republic of ChinaTel +86 1 375 826 4531; +86 1 358 870 8507Fax +86 05 718 604 4817Email xialiqun@zju.edu.cn; 3193119@zju.edu.cnPurpose: To explore if bexarotene (BEX) synergistically enhances docetaxel (DTX) cytotoxicity in castration-resistant prostate cancer cell lines.Materials and methods: MTT assay was used to measure the cytotoxic effect of DTX and BEX on castration-resistant prostate cancer (CRPC) cell proliferation and the combination index (CI) values calculated to analyze the interaction between DTX and BEX. Flow cytometry and Western blot analysis identified the underlying mechanism for the synergistic effect of BEX and DTX.Results: When mitotic slippage happens, BEX can synergistically strengthen the anti-proliferation of DTX in a way of significantly down-regulating cyclinB1 and CDK1 expression, and then arresting cells in G2 phase.Conclusion: Results from this study showed that BEX-induced G2 arrest and DTX-induced mitotic arrest probably contributed to the synergistic effect of BEX and DTX.Keywords: docetaxel, bexarotene, prostate cancer, combination therapy, cell cycle arrestCorrigendumfor this paper has been published

In this paper, we consider numerical solutions of a time domain acoustic-elastic wave interaction problem which occurs between a bounded penetrable elastic body and a compressible inviscid fluid. It is also called the fluid-solid interaction problem. Firstly, an artificial boundary is introduced to transform the original transmission problem into a problem in a bounded region, and then its well-posed results are presented. We then employ a symmetric interior penalty discontinuous Galerkin method for the solution of the reduced interaction problem consisting of second-order wave equations. A priori error estimate in the energy norm is presented, and numerical results confirm the accuracy and validity of the proposed method., Comment: Submitted to ESAIM M2AN

In this paper, we aim to develop a hybridizable discontinuous Galerkin (HDG) method for the indefinite time-harmonic Maxwell equations with the perfectly conducting boundary in the three-dimensional space. First, we derive the wavenumber explicit regularity result, which plays an important role in the error analysis for the HDG method. Second, we prove a discrete inf-sup condition which holds for all positive mesh size $h$, for all wavenumber $k$, and for general domain $\Omega$. Then, we establish the optimal order error estimates of the underlying HDG method with constant independent of the wavenumber. The theoretical results are confirmed by numerical experiments.

A new fully discrete linearized $H^1$-conforming Lagrange finite element method is proposed for solving the two-dimensional magneto-hydrodynamics equations based on a magnetic potential formulation. The proposed method yields numerical solutions that converge in general domains that may be nonconvex, nonsmooth and multi-connected. The convergence of subsequences of the numerical solutions is proved only based on the regularity of the initial conditions and source terms, without extra assumptions on the regularity of the solution. Strong convergence in $L^2(0,T;{\bf L}^2(\Omega))$ was proved for the numerical solutions of both ${\bm u}$ and ${\bm H}$ without any mesh restriction.

A stair-like generalized predictive control (GPC)strategy based on multiple models switching for a 4-wheel-drive with 4 hub motors is presented in this paper. It ensures that the vehicle can change its motion softly and meet real-time optimal control requirements of systems with jumping parameters. The strong nonlinear dynamics and interaction characteristics of electric vehicle result in large model uncertainties and the conventional robust or parameter adaptive control methods can hardly ensure the stability and accuracy of vehicle motion without delay. A conventional adaptive vehicle model, an assigned initial value vehicle model and multiple fixed models are established to identify the vehicle dynamic characteristic in parallel. Multiple fixed vehicle models can improve the transient performance. Moreover, we ensure the stability of vehicle systems by the conventional adaptive vehicle and further enhance vehicle transient performance by the assigned initial value adaptive vehicle model. The best sub-model is selected as global model according to the switching index, and a stair-like generalized predictive controller is designed for this model in electric vehicle. Due to the GPC method employed in the design, the computation complexity and cost are greatly reduced. As a result, the vehicle delivers superior performance in hazardous driving conditions.

Consider a time-harmonic acoustic point source incident on a bounded isotropic linearly elastic body immersed in a homogeneous compressible inviscid fluid. This paper is concerned with the inverse fluid-solid interaction (FSI) problem of recovering the elastic body from near-field data generated by infinitely many incident point source waves at a fixed energy. The incident point sources and the receivers for recording scattered signals are both located on a non-spherical closed surface, on which an outgoing-to-incoming (OtI) operator is appropriately defined. We provide a theoretical justification of the factorization method for precisely characterizing the scatterer by utilizing the spectrum of the near-field operator. This generalizes the imaging scheme developed in [G. Hu, J. Yang, B. Zhang, H. Zhang, Inverse Problems 30 (2014): 095005] to the case when near-field data are measured on non-spherical surfaces. Numerical examples in 2D are demonstrated to show the validity and accuracy of the inversion algorithm, even if limited aperture data are available on one or several line segments.

The aim of this study was to investigate the protective effects of Tongluo-Jiunao (TLJN) injection on brain tissues of focal cerebral ischemia-reperfusion injury rats. Cerebral ischemia-reperfusion injury rat model was established by middle cerebral artery occlusion. All animal models were divided into the following four groups: sham, model, TLJN, and edaravone groups. The brain infarct volume, concentration of IGF-1 in brain tissues and serum were detected at 24 h, 3 d, and 7 d after cerebral ischemia-reperfusion injury. The results showed that compared to the model group, the brain infarct volume of TLJN group was significantly reduced, and the expression of IGF-1 of cerebral cortex was upregulated in TLJN group. It was concluded that TLJN has significant protective effects on brain tissues in focal cerebral ischemia-reperfusion injury rat, and the IGF-1 may play an important role in the protective effects of brain tissues.