235 research outputs found

    Electromagnetic-Circuital-Thermal-Mechanical Multiphysics Numerical Simulation Method For Microwave Circuits

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    An electromagnetic-circuital-thermal-mechanical Multiphysics numerical method is proposed for the simulation of microwave circuits. The discontinuous Galerkin time-domain (DGTD) method is adopted for electromagnetic simulation. The time-domain finite element method (FEM) is utilized for thermal simulation. The circuit equation is applied for circuit simulation. The mechanical simulation is also carried out by FEM method. A flexible and unified Multiphysics field coupling mechanism is constructed to cover various electromagnetic, circuital, thermal and mechanical Multiphysics coupling scenarios. Finally, three numerical examples emulating outer space environment, intense electromagnetic pulse (EMP) injection and high-power microwave (HPM) illumination are utilized to demonstrate the accuracy, efficiency, and capability of the proposed method. The proposed method provides a versatile and powerful tool for the design and analysis of microwave circuits characterized by intertwined electromagnetic, circuital, thermal and stress behaviors

    A Sensitive Film Structure Improvement of Reduced Graphene Oxide Based Resistive Gas Sensors

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    This study was focused on how to improve the gas sensing properties of resistive gas sensors based on reduced graphene oxide. Sol-airbrush technology was utilized to prepare reduced graphene oxide films using porous zinc oxide films as supporting materials mainly for carbon dioxide sensing applications. The proposed film structure improved the sensitivity and the response/recovery speed of the sensors compared to those of the conventional ones and alleviated the restrictions of sensors\u27 performance to the film thickness. In addition, the fabrication technology is relatively simple and has potential for mass production in industry. The improvement in the sensitivity and the response/recovery speed is helpful for fast detection of toxic gases or vapors in environmental and industrial applications

    Bruceine A

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    The title compound, C26H34O11, known as bruceine A, is a natural quassinoid extracted from the dried fruits of Brucea javanica. Its structure consists of five fused rings including an oxygen-containing heterocyclic ring and a lactone ring. Two intra­molecular O—H⋯O links help to establish the mol­ecular conformation. In the crystal, O—H⋯O hydrogen bonds connect the mol­ecules

    Time-reversal symmetry breaking driven topological phase transition in EuB6_6

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    The interplay between time-reversal symmetry (TRS) and band topology plays a crucial role in topological states of quantum matter. In time-reversal-invariant (TRI) systems, the inversion of spin-degenerate bands with opposite parity leads to nontrivial topological states, such as topological insulators and Dirac semimetals. When the TRS is broken, the exchange field induces spin splitting of the bands. The inversion of a pair of spin-splitting subbands can generate more exotic topological states, such as quantum anomalous Hall insulators and magnetic Weyl semimetals. So far, such topological phase transitions driven by the TRS breaking have not been visualized. In this work, using angle-resolved photoemission spectroscopy, we have demonstrated that the TRS breaking induces a band inversion of a pair of spin-splitting subbands at the TRI points of Brillouin zone in EuB6_6, when a long-range ferromagnetic order is developed. The dramatic changes in the electronic structure result in a topological phase transition from a TRI ordinary insulator state to a TRS-broken topological semimetal (TSM) state. Remarkably, the magnetic TSM state has an ideal electronic structure, in which the band crossings are located at the Fermi level without any interference from other bands. Our findings not only reveal the topological phase transition driven by the TRS breaking, but also provide an excellent platform to explore novel physical behavior in the magnetic topological states of quantum matter.Comment: 22 pages, 7 figures, accepted by Phys. Rev.

    Overexpression of YAP 1 contributes to progressive features and poor prognosis of human urothelial carcinoma of the bladder

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    BACKGROUND: Yes-associated protein 1 (YAP 1), the nuclear effector of the Hippo pathway, is a key regulator of organ size and a candidate human oncogene in multiple tumors. However, the expression dynamics of YAP 1 in urothelial carcinoma of the bladder (UCB) and its clinical/prognostic significance are unclear. METHODS: In this study, the methods of quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting and immunohistochemistry (IHC) were utilized to investigate mRNA/ protein expression of YAP 1 in UCBs. Spearman’s rank correlation, Kaplan-Meier plots and Cox proportional hazards regression model were used to analyze the data. RESULTS: Up-regulated expression of YAP 1 mRNA and protein was observed in the majority of UCBs by qRT-PCR and Western blotting, when compared with their paired normal bladder tissues. By IHC, positive expression of YAP 1 was examined in 113/213 (53.1%) of UCBs and in 6/86 (7.0%) of normal bladder specimens tissues. Positive expression of YAP 1 was correlated with poorer differentiation, higher T classification and higher N classification (P < 0.05). In univariate survival analysis, a significant association between positive expression of YAP 1 and shortened patients’ survival was found (P < 0.001). In different subsets of UCB patients, YAP 1 expression was also a prognostic indicator in patients with grade 2 (P = 0.005) or grade 3 (P = 0.046) UCB, and in patients in pT1 (P = 0.013), pT2-4 (P = 0.002), pN- (P < 0.001) or pT2-4/pN- (P = 0.004) stage. Importantly, YAP 1 expression (P = 0.003) together with pT and pN status (P< 0.05) provided significant independent prognostic parameters in multivariate analysis. CONCLUSIONS: Our findings provide evidences that positive expression of YAP 1 in UCB may be important in the acquisition of an aggressive phenotype, and it is an independent biomarker for poor prognosis of patients with UCB

    Transplantation of Gut Microbiota From High-Fat-Diet-Tolerant Cynomolgus Monkeys Alleviates Hyperlipidemia and Hepatic Steatosis in Rats.

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    Emerging evidence has been reported to support the involvement of the gut microbiota in the host's blood lipid and hyperlipidemia (HLP). However, there remains unexplained variation in the host's blood lipid phenotype. Herein a nonhuman primate HLP model was established in cynomolgus monkeys fed a high-fat diet (HFD) for 19 months. At month 19%, 60% (3/5) of the HFD monkeys developed HLP, but surprisingly 40% of them (2/5) exhibited strong tolerance to the HFD (HFD-T) with their blood lipid profiles returning to normal levels. Metagenomic analysis was used to investigate the compositional changes in the gut microbiota in these monkeys. Furthermore, the relative abundance of remarkably increased and became the dominant gut microbe in HFD-T monkeys. A validation experiment showed that transplantation of fecal microbiota from HFD-T monkeys reduced the blood lipid levels and hepatic steatosis in HLP rats. Furthermore, the relative abundance of significantly increased in rats receiving transplantation, confirming the successful colonization of the microbe in the host and its correlation with the change of the host's blood lipid profiles. Our results thus suggested a potentially pivotal lipid-lowering role of in the gut microbiota, which could contribute to the variation in the host's blood lipid phenotype. [Abstract copyright: Copyright © 2022 Gao, Rao, Wei, Xia, Huang, Tang, Hide, Zheng, Li, Zhao, Sun and Chen.
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