Liver fibrosis is a reversible pathological overreaction during the self‐repair of liver injuries, and it is the common period of chronic liver diseases induced by different pathogenesis progress ...into cirrhosis and even hepatocellular carcinoma. Pyroptosis, a novel form of programmed cell death, is reported to take part in the pathogenesis and progression of acute or chronic liver diseases and liver fibrosis. Caspase‐1 dependent canonical pathway and caspase‐4/‐5/‐11 mediated noncanonical pathway are the two signalling pathways to induce pyroptosis. The activation of inflammasomes under the stimulation of pathogenic microorganisms and danger signals can initiate the pyroptotic pathway and release large amounts of proinflammatory and profibrotic cytokines. This article comprehensively summarizes recent researches focused on the mechanism of pyroptosis and its role in major hepatic cells, which can provide potential therapeutic strategies for liver fibrosis.
This communication presents a Fabry-Pérot resonator antenna (FPRA) with the dual-band dual-orthogonal circular polarization (CP). The whole FPRA consists of a linearly polarized (LP) microstrip patch ...antenna and a chiral metamaterial (CMM) superstrate. The LP microstrip antenna serves as the feed system, while the CMM superstrate has the function of polarization transformation. The CMM also works as a partial reflective sheet to form an FPRA. The ray-tracing method in the circular base is introduced to describe the mechanism of this type of FPRA. Furthermore, the procedure of controlling the frequency ratio of two bands is discussed as well. An antenna prototype is fabricated to validate the simulated results. In the frequency band from 7.24 to 7.36 GHz, the proposed FPRA produces right-handed CP wave. However, left-handed CP wave is achieved when the frequency ranges from 7.96 to 8.14 GHz. The realized gains reach 12.98 dBic at 7.28 GHz and 13.25 dBic at 8 GHz, respectively.
Radar-absorbing materials are used in stealth technologies for concealment of an object from radar detection. Resistive and/or magnetic composite materials are used to reduce the backscattered ...microwave signals. However, nontunable characteristics or the required complex structure hampered the application of these materials. Here, multilayer graphene-based frequency selective surfaces (MLGFSS), which reach a size of 150 mm <inline-formula> <tex-math notation="LaTeX">\times </tex-math></inline-formula> 150 mm, are designed and fabricated. By properly changing the growth temperature of MLG using the chemical vapor deposition approach and designing the pattern of graphene layer, the impedance matching condition can be satisfied at different frequencies. As a result, two kinds of absorbers with different working bandwidths are realized. The performances of the proposed absorbers are analyzed using full-wave simulation and are also tested with experimental results. Our method of fabricating large-area MLGFSS avoids the direct contact between the stencil mask and graphene, and guarantees the integrity and quality of patterned graphene structure. A good agreement between simulation and measurement results demonstrates that such ultrathin MLGFSS is very useful in the design of graphene-based functional devices at microwave frequencies.
Abstract
Background
Acute liver failure (ALF) is a syndrome of severe hepatocyte injury with high rate of mortality. Hepatitis B virus (HBV) infection is the major cause of ALF worldwide, however, ...the underlying mechanism by which HBV infection leads to ALF has not been fully disclosed.
Methods
D-GalN-induced hepatocyte injury model and LPS/D-GalN-induced ALF mice model were used to investigate the effects of HBV X protein (HBx) in vitro and in vivo, respectively. Cell viability and the levels of Glutathione (GSH), malondialdehyde (MDA) and iron were measured using commercial kits. The expression of ferroptosis-related molecules were detected by qRT-PCR and western blotting. Epigenetic modification and protein interaction were detected by chromatin immunoprecipitation (ChIP) assay and co-immunoprecipitation (co-IP), respectively. Mouse liver function was assessed by measuring aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The histological changes in liver tissues were monitored by hematoxylin and eosin (H&E) staining, and SLC7A11 immunoreactivity was assessed by immunohistochemistry (IHC) analysis.
Results
D-GalN triggered ferroptosis in primary hepatocytes. HBx potentiated D-GalN-induced hepatotoxicity and ferroptosis in vitro, and it suppressed SLC7A11 expression through H3K27me3 modification by EZH2. In addition, EZH2 inhibition or SLC7A11 overexpression attenuated the effects of HBx on D-GalN-induced ferroptosis in primary hepatocytes. The ferroptosis inhibitor ferrostatin-1 (Fer-1) protected against ALF and ferroptosis in vivo. By contrast, HBx exacerbates LPS/D-GalN-induced ALF and ferroptosis in HBx transgenic (HBx-Tg) mice.
Conclusion
HBx facilitates ferroptosis in ALF via EZH2/H3K27me3-mediated SLC7A11 suppression.
In this article, a chiral metamaterial (CMM) with high reflectance is constructed by using both the S‐shaped strip and the grid strip. Numerical simulation results reveal that the reflectance reaches ...0.7 and the transmitted wave is converted from y‐polarization to left‐hand circular polarization. Therefore, the proposed CMM has the function of polarized transformation from linear polarization (LP) wave to circular polarization (CP). In addition, a Fabry‐Perot resonator cavity‐like behavior is found in the CMM itself. We design and measure a CP CMM‐based Fabry‐Pérot resonator cavity antenna. A bandwidth of 13.25% (|S11| < −10 dB, AR < 3 dB, and peak gain drop<3 dB) and a peak gain of 14.76 dBic are attained. The proposed antenna has potential applications in advanced nanosatellite communication systems.
The existing research studies on adaptive control frequently introduce many parameter estimations and lead to a complicated controller. This paper investigates the robust regulation issue for ...high-order system and plants to raise a new approach for adaptive control. Specifically, the considered system has odd system power, nontriangular form, and external disturbance. By introducing the transformations of a parameter estimation, the studied system is transformed into a new dynamic system. By employing fuzzy systems and some inequality skills, the appropriate bounds of nonlinear terms are established. Based on the adaptive method and homogeneous control, a recursive control design algorithm is provided to construct a new adaptive controller, which dominates those uncertain bounds and guarantees that the closed-loop system is semiglobally uniformly ultimately bounded (SUUB). The constructed controller employs only one adaptive law and has a much simpler form. Simulation examples verify the validness of the presented method.
This work focuses on presenting a control algorithm to investigate nonlinear systems, which contain time-varying powers, inverse dynamics, and uncertainties. First, some appropriate transformations ...are introduced to obtain a new system. Then, a Lyapunov function, which covers quadratic and high-order components, is recursively constructed for control design. Subsequently, by introducing the neural networks, the uncertain functions encountered during the design are approximated. Based on the inequality techniques, the nonlinear terms are skillfully estimated. By defining the bounds of some unknown parameters and using the adaptive technique, some virtual controllers are selected in each step to dominate the nonlinear functions and guarantee that the derivative of the Lyapunov function satisfies the required form. Finally, a new adaptive controller is constructed and semiglobal practical finite time stability (SGPFS) is guaranteed. The proposed approach is verified with a numerical example.
A novel compact low-profile circularly polarized Fabry-Perot resonator (CP-FPR) antenna fed by a linearly polarized microstrip patch tilting by 45 ° with respect to the axes is presented. The FP ...cavity consists of a partially reflective surface formed by cross-slot frequency selective surface (FSS) and a nonstandard artificial magnetic conductor (AMC) acting as reflective ground plane. Its profile is reduced to a quarter of a wavelength. For verification, a prototype antenna is designed and simulated by HFSS. Reasonable agreement between the simulated and measured results is observed. The prototype has a common frequency bandwidth of 6.4% for S 11 ≤ - 10 dB, gain-drop ≤ 3 dB, and axial ratio ≤ 3 dB.
With the development of radar and communication system, frequency selective rasorber (FSR) is in great need. In this article, a flexible rasorber based on graphene is presented and investigated. A ...passband with small insertion loss and two absorption bands with high absorptivity below and above the passband is realized. Without welding lumped elements, our design can be applied to wide wavelength regions from microwave to low terahertz range, and also conformal situations. Besides, by integrating graphene sandwich structure (GSS), tunable transmission at the passband of the rasorber is realized, which makes our rasorber have the function of energy manipulation. For experimental demonstration, the rasorber prototype is fabricated and measured at microwave region; the fabricated sample shows good flexibility and good tunability, demonstrating that our radome has great application prospect in the field of electromagnetic stealth, compatibility, and protection.
Mg–Al-layered double hydroxide (LDH) coatings were fabricated by a combined co-precipitation method and hydrothermal process on an AZ31 alloy substrate. The characteristics of the coatings were ...investigated using SEM, XRD, FT-IR and EDS. The corrosion resistance of the LDH coatings was studied using potentiodynamic polarization and electrochemical impedance spectrum. The results demonstrated that the LDH coatings, characterized by nanoplates stacked vertically to the substrate surface and ion-exchange ability, possess excellent corrosion resistance.
•The microstructure of the LDH coatings was composed of the nanoplates.•The LDH-coated alloys possess excellent anticorrosion property.•The LDH coatings possess the ion-exchangeability.
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