Excitation and propagation of surface plasmon polaritons on a non-structured surface with a permittivity gradient.

Accompanied by the rise of plasmonic materials beyond those based on noble metals and the development of advanced materials processing techniques, it is important to understand the plasmonic behavior of materials with large-scale inhomogeneity (such as gradient permittivity materials) because they cannot be modeled simply as scatterers. In this paper, we theoretically analyze the excitation and propagation of surface plasmon polaritons (SPPs) on a planar interface between a homogeneous dielectric and a material with a gradient of negative permittivity. We demonstrate the following: (i) free-space propagating waves and surface waves can be coupled by a gradient negative-permittivity material and (ii) the coupling can be enhanced if the material permittivity variation is suitably designed. This theory is then verified by numerical simulations. A direct application of this theory, rainbow trapping, is also proposed, considering a realistic design based on doped indium antimonide. This theory may lead to various applications, such as ultracompact spectroscopy and dynamically controllable generation of SPPs

in KKAy mice

and mechanisms of resveratrol on the amelioration of oxidative stress and hepatic steatosi

Adaptive beamforming for optical wireless communication via fiber modal control

High-speed optical wireless communication can address the exponential growth in data traffic. Adaptive beamforming customized for the target location is crucial, but existing solutions such as liquidcrystal spatial light modulators and microelectromechanical systems require costly micro/nano manufacturing, delicate alignment, and a high degree of mechanical stability. These challenges reflect the fragility of integrating a fiber network with micro/nano mechanical or photonic systems. Here, we realize low-cost, low-loss, and fiber-compatible beamforming and continuous beam steering through controlled bending of a multi-mode fiber that modifies its modal coupling, and use it to enable flexible optical wireless communication at 10 Gb/s. By using the fiber modal coupling as degrees of freedom rather than an impediment, this approach offers a promising solution for flexible and cost-effective optical wireless communication networks.Comment: 17 pages, 7 figure

BCAA dysmetabolism in the host and gut microbiome, a key player in the development of obesity and T2DM

Branched chain amino acids (BCAAs) are essential amino acids required by mammals. Recently, accumulating evidence has revealed the important connection between the alterations of BCAAs and their metabolites in circulation and the development and prognosis of chronic metabolic diseases, especially obesity and type 2 diabetes mellitus (T2DM). The connection strongly suggests the pivotal role of dysregulated BCAA metabolism in obesity and T2DM. More importantly, BCAA anabolic and catabolic defects in host and gut microbiome often intertwine with glucose and lipid metabolism, which synergistically promote systemic insulin resistance and obesity/T2DM progression. However, the mutual effects of BCAA with glucose/lipid metabolism in different tissues of the host and the association of BCAA with gut microbiota, are not fully understood and summarized. In the current review, we focus on the mutual effects of BCAA with glucose/lipid metabolism in the host and gut microbiota modulation of BCAA metabolism, and further discuss the metabolic regulatory effects on the development of obesity and T2DM

Experimental study on particle deposition of Fe3O4 in supercritical heat exchange tube

Particle deposition poses a significant challenge to the economics and safety of supercritical boilers. Under-standing the deposition behavior of particles on the steam-water side wall is essential. A supercritical particle deposition system was designed and build according to the actual conditions. The effects of fluid thermal state, flow rate and exposure time on particle morphology, deposition layer morphology and deposition distribution were investigated. The results showed that FeCl2 was oxidized to micron sized Fe3O4 particle, and the salt crystals had a redissolution behavior in supercritical water. The particle deposition layer was a three-layer structure, possibly related to the gas-like fluid clusters and turbulence. The deposition distribution was related to the flow state, and there was a forward shift of the peak point with exposure time. Our results help to un-derstand the particle deposition behavior in supercritical heat exchangers

A CFD study of the effects of combined impurities, ground temperature, and topography upon the consequence distances and plume shapes generated by CO2 release from CCS pipeline failure

In the carbon capture and storage (CCS) infrastructure, the risk of a high-pressure buried pipeline rupture possibly leads to catastrophic accidents due to the release of tremendous amounts of carbon dioxide (CO2). Therefore, it is crucial to conduct an in-depth study on CO2 atmospheric dispersion when developing CO2 pipeline. In fact, the CO2 captured from diverse industrial processes may contain a variety of impurities. The combined effect of the toxicities of the multiple impurities increases the risk, which has usually been ignored by previous studies. In this paper, computational fluid dynamics (CFD) technology is applied to investigate the influence of hazardous chemicals on CO2 stream dispersion under different meteorological, complex terrain features, and ground temperature condition. In addition, the effect of combined toxic impurities on consequence distance was also investigated comprehensively. It was found that complex conditions affected the near-surface flow field, and obstacles enhanced the lateral dispersion of CO2. Compared to 288 K ground temperature, the plume area inside the 50,000 ppmv CO2 boundary decreased by 8.2%. The hazardous effects of combined toxic impurities became significant compared to a single toxic impurity. This study may furnish a viable assessment technique for the risks associated with CCS

Designation of Pump-Signal Combiner with Negligible Beam Quality Degradation for a 15 kW Tandem-Pumping Fiber Amplifier

In this paper, the fabrication method of a pump/signal (6 + 1) × 1 combiner based on a large-core (48 μm) multimode signal fiber is introduced. Since the signal fiber is not tapered in the production, and an effective feedback alignment method is adopted during the splice process, the degradation ratio of the M2 value of the signal light is only about 5% after passing through the beam combiner. In addition, with the help of a home-made beam combiner, a counter-directional tandem-pumping amplifier is built. The maximum output power of the amplifier is 15.31 kW with the slope efficiency of 83.2%. The temperature rise coefficient of the home-made combiner is 3.2 °C/kW and the backward isolation degree is more than 36 dB from each pump pigtail. Both test results prove the outstanding potential of the pump-signal combiner in high-power laser applications

Percutaneous retrograde puncture of occluded common femoral artery combined with SAFARI for recanalization of iliac-femoral-BTK arterial occlusion

This report describes the recanalization of iliac-femoral-popliteal-below the knee super-long chronic total occlusion (CTO) in a patient with chronic limb-threatening ischemia. We attempted recanalization with the SAFARI technique but failed because the retrograde guidewire could not re-enter into the true lumen of the common iliac artery. Then we conducted an additional retrograde puncture of the occluded common femoral artery and created a “flossing”-type guidewire to achieve revascularization. We combined the techniques of SAFARI and retrograde puncture of the occluded common femoral artery, which may represent a new strategy for revascularizing such kind of challenging super-long CTO