The MERS-CoV N Protein Regulates Host Cytokinesis and Protein Translation via Interaction With EF1A

Middle East respiratory syndrome coronavirus (MERS-CoV), a pathogen causing severe respiratory disease in humans that emerged in June 2012, is a novel beta coronavirus similar to severe acute respiratory syndrome coronavirus (SARS-CoV). In this study, immunoprecipitation and proximity ligation assays revealed that the nucleocapsid (N) protein of MERS-CoV interacted with human translation elongation factor 1A (EF1A), an essential component of the translation system with important roles in protein translation, cytokinesis, and filamentous actin (F-actin) bundling. The C-terminal motif (residues 359–363) of the N protein was the crucial domain involved in this interaction. The interaction between the MERS-CoV N protein and EF1A resulted in cytokinesis inhibition due to the formation of inactive F-actin bundles, as observed in an in vitro actin polymerization assay and in MERS-CoV-infected cells. Furthermore, the translation of a CoV-like reporter mRNA carrying the MERS-CoV 5′UTR was significantly potentiated by the N protein, indicating that a similar process may contribute to EF1A-associated viral protein translation. This study highlights the crucial role of EF1A in MERS-CoV infection and provides new insights into the pathogenesis of coronavirus infections

A sensor with coating Pt/WO3 powder with an Erbium-doped fiber amplifier to detect the hydrogen concentration

A highly sensitive hydrogen sensor coated with Pt/WO3 powder with an Erbium-doped fibre amplifier (EDFA) is proposed and experimentally demonstrated. The sensing head is constructed by splicing a short section of tapered small diameter coreless fiber (TSDCF diameter of 62.5 μm, and tapered to 14.5 μm) between two single-mode fibres. The Pt/WO3 powder adheres to the surface of PDMS film coated on the TSDCF structure, which is sensitive to hydrogen. An EDFA is introduced into the sensor system to improve the quality factor of the output spectrum and thus improve the sensor’s resolution. As the hydrogen concentration varies from 0 to 1.44, the measured maximum light intensity variation and the sensor’s sensitivity are -32.41 dB and -21.25 dB/, respectively. The sensor demonstrates good stability with the light intensity fluctuation of < 1.26 dB over a 30-minute duration

Research on Lightning Overvoltage Characteristics of High-Voltage Diode Rectifier

Failure of the high-voltage diode rectifier caused by lightning will cause huge losses. The traditional analysis of overvoltage induced by the high-voltage diode rectifier shell under lightning stroke cannot adapt to the overvoltage process caused by lightning stroke-induced conduction invading the inside of the high-voltage diode rectifier. Therefore, this paper proposes to establish a high-frequency equivalent model of the core components of the high-voltage diode rectifier, including diodes, reactors, transformers, and overhead lines. On this basis, a lightning overvoltage model of lightning-induced conduction into the high-voltage diode rectifier is built, and the transient process of diode lightning overvoltage under the constraint of reverse recovery charge is analyzed. Then, we describe the transient distribution of overvoltage in high-voltage diode rectifiers caused by lightning stroke. The transient distribution of overvoltage induced by lightning in series diodes under different diode equivalent models is analyzed by simulation. The simulation results show that the inconsistent parameters of series diodes can easily lead to diode damage due to uneven voltage distribution when lightning strikes. Therefore, this paper puts forward a scheme to reduce lightning damage, including selecting diodes with the same parameters and adding fast-melting fuses at the transformer’s secondary side and in front of the series diode bridge arm. The simulation shows that the scheme proposed in this paper can effectively prevent the high-voltage diode rectifier from being damaged by lightning strikes

Two Thermochromic Layered Iodoargentate Hybrids Directed by 4- and 3‑Cyanopyridinium Cations

Two layered iodoargentates, [HCP]­[Ag₂I₃] (HCP⁺ = NH-4-cyanopyridinium) (<b>1</b>) and [MCP]­[Ag₄I₅] (MCP⁺ = <i>N</i>-methyl-3-cyanopyridinium) (<b>2</b>) have been solvothermally synthesized. For <b>1</b>, the inorganic layer is built up by 4-connected Ag₄I₈ unit with cubane-type Ag₄I₄ core via sharing peripheral μ₂-I in <i>ab</i> plane, while the HCP⁺ cations are located at the apertures and interlayer space. For <b>2</b>, the inorganic layer is constructed from [Ag₆I₆]_<i>n</i> and [AgI₃]_<i>n</i>^2<i>n</i>– chains via alternative corner- and edge-sharing modes along the <i>b</i>-axis, while the MCP⁺ cations lie between neighboring layers. Compounds <b>1</b> and <b>2</b> exhibit reducing band gaps relative to the bulk β-AgI and remarkable thermochromism, which are ascribed to the intermolecular charge transfer (CT) and affected by electron affinity of pyridinium cations

Acoustic Imaging with Metamaterial Luneburg Lenses

Abstract The Luneburg lens is a spherically symmetrical gradient refractive index (GRIN) device with unique imaging properties. Its wide field-of-view (FoV) and minimal aberration have lead it to be successfully applied in microwave antennas. However, only limited realizations have been demonstrated in acoustics. Previously proposed acoustic Luneburg lenses are mostly limited to inherently two-dimensional designs at frequencies from 1 kHz to 7 kHz. In this paper, we apply a new design method for scalable and self-supporting metamaterials to demonstrate Luneburg lenses for airborne sound and ultrasonic waves. Two Luneburg lenses are fabricated: a 2.5D ultrasonic version for 40 kHz and a 3D version for 8 kHz sound. Imaging performance of the ultrasonic version is experimentally demonstrated

Rational Engineering of 2D Materials as Advanced Catalyst Cathodes for High‐Performance Metal–Carbon Dioxide Batteries

Given the unique characteristic of integrating CO2 conversion and renewable energy storage, metal–CO2 batteries (MCBs) are expected to become the next‐generation technology to address both environmental and energy crises. As involving complex gas–liquid–solid three‐phase interfacial reactions, cathodes of MCBs can significantly affect the overall battery operation, thus attracting much research attention. Compared to conventional materials, 2D materials offer great opportunities for the design and preparation of high‐performance catalyst cathodes, especially showing superior bifunctional electrocatalytic capacity for rechargeable MCBs. The inherent high‐specific‐surface area and diverse structural architectures of 2D materials enable their flexible and rational engineering designs toward kinetically favorable metal–CO2 electrochemistry. Herein this review, the cutting‐edge progresses of 2D materials‐based catalyst cathodes are presented in MCBs. The reaction mechanisms of various MCBs, including both nonaqueous and aqueous systems, are systematically introduced. Then, the design criteria of catalyst cathodes, and the merits and demerits of 2D materials‐based catalyst cathodes are discussed. After that, three representative engineering strategies (i.e., defect control, phase engineering, and heterostructure design) of 2D materials for high‐performance MCBs are systematically described. Finally, the current research advances are briefly summarized and the confronting challenges and opportunities for future development of advanced MCB cathodes are proposed