Search

Copyright of Journal of Zhejiang University: Science A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hepatocellular carcinoma (HCC) caused by HBV, HCV infection, and other factors is one of the most common malignancies in the world. Although, percutaneous treatments such as surgery, ethanol injection, radiofrequency ablation, and transcatheter treatments such as arterial chemoembolization are useful for local tumor control, they are not sufficient to improve the prognosis of patients with HCC. External interferon agents that induce interferon-related genes or type I interferon in combination with other drugs can reduce the recurrence rate and improve survival in HCC patients after surgery. Therefore, in this review, we focus on recent advances in the mechanism of action of type I interferons, emerging therapies, and potential therapeutic strategies for the treatment of HCC using IFNs. [ABSTRACT FROM AUTHOR]

In this paper, a new HIV CD4 + T cells reaction-diffusion model has been introduced, which aims to explore the joint impact of cell-free infection, cytokine-enhanced viral infection, CTL immune response and time delay. Our results show that inflammatory cytokine infection, time delay and reaction-diffusion play an important role in HIV model and can not be ignored. First, we investigate the existence and nonnegativity of the solution of the model. Then, we obtain the existence of three equilibria namely infection-free equilibrium E 0 , immune-free equilibrium E 1 and immunity-inactivated equilibrium E 2 respectively. Next, two threshold parameters R 0 (basic reproduction number) and R CTL (immune response reproduction number) are defined, which determine the dynamic behavior of the model. Using Lyapunov functionals and LaSalle's invariance principle, we show that E 0 is globally asymptotically stable when R 0 ≤ 1 ; If R 0 > 1 , the model is uniformly persistent and E 1 is globally asymptotically stable when R CTL < 1 < R 0 ; E 2 is globally asymptotically stable when R 0 > 1 and R CTL > 1 . Finally, a special case is given to show the global attractiveness of the three equilibria by numerical simulation. [ABSTRACT FROM AUTHOR]

In this paper, three new third-order accurate schemes are proposed and analyzed for the phase field crystal equation modeled by the Swift-Hohenberg energy functional with periodic boundary conditions based on three types of convex splittings. Firstly, using a third-order backward differentiation formula for the temporal discretization, we treat the convex and concave parts produced by the energy splitting implicitly and explicitly, respectively. Next, we develop three nonlinear third-order semi-discrete schemes and present rigorous proofs of the mass conservation, unique solvability, and the energy stability. The Fourier pseudo-spectral method is utilized for the spatial discretization and some advanced nonlinear iterative solvers are applied to solve the discrete system. Furthermore, various numerical experiments in two and three dimensional are presented to demonstrate the accuracy, energy stability, and mass conservation of the proposed schemes. [ABSTRACT FROM AUTHOR]

This paper investigates the stability of a class of fractional-order static neural networks. Two new Lyapunov functions with proper integral terms are constructed. These integrals with variable upper limit are convex functions. Based on the fractional-order Lyapunov direct method and some inequality skills, several novel stability sufficient conditions which ensure the global Mittag–Leffler stability of fractional-order projection neural networks (FPNNs) are presented in the forms of linear matrix inequalities (LMIs). Two LMI-based Mittag–Leffler stability criteria with less conservativeness are given for a special kind of FPNNs. Finally, the effectiveness of the proposed method is demonstrated via four numerical examples. [ABSTRACT FROM AUTHOR]

As an inverse problem, particle reconstruction in tomographic particle image velocimetry attempts to solve a large-scale underdetermined linear system using an optimization technique. The most popular approach, the multiplicative algebraic reconstruction technique (MART), uses entropy as an objective function in the optimization. All available MART-based methods are focused on improving the efficiency and accuracy of particle reconstruction. However, those methods do not perform very well on dealing with ghost particles in highly seeded measurements. In this report, a new technique called dual-basis pursuit (DBP), which is based on the basis pursuit technique, is proposed for tomographic particle reconstruction. A template basis is introduced as a priori knowledge of a particle intensity distribution combined with a correcting basis to enable a full span of the solution space of the underdetermined linear system. A numerical assessment test with 2D synthetic images indicated that the DBP technique is superior to MART method, can completely recover a particle field when the number of particles per pixel ( ppp) is less than 0.15, and can maintain a quality factor Q of above 0.8 for ppp up to 0.30. Unfortunately, the DBP method is difficult to utilize in 3D applications due to the cost of its excessive memory usage. Therefore, a dual-basis MART was designed that performed better than the traditional MART and can potentially be utilized for 3D applications. [ABSTRACT FROM AUTHOR]

In magnetic flux leakage (MFL) testing technology, the MFL signals are thought to result from all defects and are used in their evaluation. The tested defects include two types of defects, concave and bump-shaped features, and recently described mechanisms in the MFL method indicate that the former defects produce positive MFL because of magnetic refraction and the latter ones produce negative magnetic fields because of self-magnetization regulation; consequently, these defects result in raised test signal waves and sunken test signal waves, respectively. Thereby, a new methodology for accurately identifying the defect type based on the mapping relation between the signal features and defect types is proposed. Both simulations and experiments with three representative defects (i.e., notch, protrusion and combination) were conducted to confirm their identification using this new methodology. Combined with MFL standards such as American Society for Testing and Materials (ASTM) E570-09 (Standard Practice for Flux Leakage Examination of Ferromagnetic Steel Tubular Products, ) and British Standards (BS) EN 10246-4 (Non-destructive Testing of Steel Tubes-Part 4: Automatic Full Peripheral Magnetic Transducer/Flux Leakage Testing of Seamless Ferromagnetic Steel Tubes for the Detection of Transverse Imperfections, ), suggestions for standard specimens with reference defects that consist of both types of defects are provided. [ABSTRACT FROM AUTHOR]