CircHIPK3 relieves vascular calcification via mediating SIRT1/PGC-1α/MFN2 pathway by interacting with FUS.

BACKGROUND: Circular RNAs (circRNAs) have been reported to regulate the biological processes of human diseases. CircHIPK3 has been implicated in vascular calcification, but the downstream regulatory mechanisms remain unclear. Our study aimed to understand the regulatory function of circHIPK3 in vascular calcification. METHODS: CircHIPK3 expression in atherosclerosis (AS) serum samples and vascular smooth muscle cells (VSMCs) calcification model was assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The binding relationships between fused in sarcoma (FUS) and circHIPK3 or sirtuin 1 (SIRT1) were verified by RNA immunoprecipitation (RIP) assay and RNA pull-down assays. Alkaline phosphatase (ALP) activity and alizarin red staining assays were performed to evaluate the biological effect of ß-glycerophosphate (ß-GP) and circHIPK3 on calcium deposition. qRT-PCR and western blot assays were used to examine the effect of ß-GP, circHIPK3, SIRT1, mitofusin 2 (MFN2), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) on VSMCs calcification and the expression of calcification-related proteins. RESULTS: In AS serum samples and VSMCs calcification model, the expression of circHIPK3 was significantly reduced. CircHIPK3 overexpression inhibited ALP activity and calcium deposition in ß-GP-induced VSMCs. Moreover, circHIPK3 could recruit FUS to further stabilize SIRT1 mRNA. CircHIPK3 promoted MFN2 expression to alleviate VSMCs calcification via activating SIRT1/PGC-1α signaling. CONCLUSION: The positive regulation of circHIPK3/FUS/SIRT1/PGC-1α/MFN2 signaling pathway contributed to the alleviate VSMCs calcification, revealing a novel regulatory axis for vascular calcification.

A Gradient Lithiophilic Structure for Stable Lithium Metal Anodes with Ultrahigh Rate and Ultradeep Capacity.

Using three-dimensional current collectors (3DCC) as frameworks for lithium metal anodes (LMAs) is a promising approach to inhibit dendrite growth. However, the intrinsically accumulated current density on the top surface and limited Li-ion transfer in the interior of 3DCC still lead to the formation of lithium dendrites, which can pose safety risks. In this study, it reports that gradient lithiophilic structures can induce uniform lithium deposition within the interior of the 3DCC, greatly suppressing dendrite formation, as confirmed by COMSOL simulations and experimental results. With this concept, a gradient-structured zinc oxide-loaded copper foam (GSZO-CF) is synthesized via an easy solution-combustion method at low cost. The resulting Li@GSZO-CF symmetric cells demonstrate stable cycling performance for over 800 cycles, with an ultra-deep capacity of 10 mAh cm-2 even under an ultra-high current density of 50 mA cm-2 , the top results reported in the literature. Moreover, when combined with a LiFePO4 (LFP) cathode under a low negative/positive (N/P) capacity ratio of 2.9, the Li@GSZO-CF||LFP full cells exhibit stable performance for 200 cycles, with a discharge capacity of 130 mAh g-1 and retention of 85.5% at a charging/discharging rate of 1C. These findings suggest a promising strategy for the development of new-generation LMAs.

Ultra-narrow multi-band polarization-insensitive plasmonic perfect absorber for sensing.

We theoretically propose a simple ultra-narrow multi-band perfect absorber for sensing applications. The perfect absorber consists of periodically arranged metallic nanodisks etched with regular prismatic holes standing on the dielectric-metal bi-layer films. Multiple ultra-narrow perfect absorption bands are obtained in the near-infrared region with the maximum bandwidth less than 21 nm and the intensity as high as 99.86%. The ultra-narrow multi-band perfect absorption originates from the synergy of localized surface plasmons, propagating surface plasmons and lattice resonances. The perfect absorber also presents other significant advantages, e.g. polarization insensitivity and high sensitivity of surrounding environments. Moreover, the prominent sensing performance for detecting the trace amounts of glucose in water is demonstrated. These features make it a promising candidate with great potential in the fields of perfect absorbers, plasmonic sensors, filters and multiplexing binding bio-molecular detection.

Semiconductor-nanoantenna-assisted solar absorber for ultra-broadband light trapping.

Light trapping is an important performance of ultra-thin solar cells because it cannot only increase the optical absorption in the photoactive region but it also allows for the efficient absorption with very little materials. Semiconductor-nanoantenna has the ability to enhance light trapping and raise the transfer efficiency of solar energy. In this work, we present a solar absorber based on the gallium arsenide (GaAs) nanoantennas. Near-perfect light absorption (above 90%) is achieved in the wavelength which ranges from 468 to 2870 nm, showing an ultra-broadband and near-unity light trapping for the sun's radiation. A high short-circuit current density up to 61.947 mA/cm2 is obtained. Moreover, the solar absorber is with good structural stability and high temperature tolerance. These offer new perspectives for achieving ultra-compact efficient photovoltaic cells and thermal emitters.

Spectral tuning of a locally bent microfiber taper interferometer with a nanosized liquid crystal overlay.

In this paper, the tuning characteristics of locally bent microfiber taper covered with a nanosized high-refractive-index liquid crystal (LC) layer under different temperatures and electric field intensities have been theoretically analyzed and experimentally investigated. A locally bent microfiber taper interferometer with a waist diameter of ∼3.72 µm is fabricated by using the flame brushing technique, followed by bending the transition region of the taper to form a modal interferometer and later by placing a ∼200 nm LC layer over the uniform taper waist region. Experimental results indicate that a high-efficiency thermal or electric tuning of an LC-coated locally bent microfiber taper interferometer could be achieved. This suggests a potential application of this device as tunable all-fiber photonic devices, such as filters, modulators, and sensing elements.

Design and analysis of a highly efficient coupler between a micro/nano optical fiber and an SOI waveguide.

A compact coupling structure is proposed for highly efficient coupling between a micro/nano fiber and a silicon-on-insulator waveguide. The proposed structure is characterized by high coupling efficiency, wavelength insensitivity, large misalignment tolerance, and easy fabrication. Theoretical analysis and numerical simulation results show that coupling efficiency of >90% can be achieved with a taper length of ∼4.5 µm.

[Spectroscopic studies on refolding process in vitro of pan-allergen profilin in coco pollen].

Recombinant proteins expressed by prokaryotic expression system are normally in the form of inclusion. In the present paper, refolding process of recombinant pan-allergen profilin protein induced by urea has been investigated by using circular dichroism spectra, fluorescence spectra, synchronous fluorescence spectra systematically. And the spectral characteristics of the renaturation were obtained. In addition, bioinformatics methods including predications of secondary and tertiary structures have also been used to explain the spectral characteristics and analyze the conformational changes of the protein during renaturation in vitro. Results from this study should be useful to the establishment of a spectral method examining the extent of protein renaturation, and be helpful to the understanding of the mechanism of renaturation of recombinant protein.

Analysis of temperature-dependent mode transition in nanosized liquid crystal layer-coated long period gratings.

The cladding mode reorganization in high refractive-index (HRI)-coated long period gratings (LPGs) is theoretically analyzed and experimentally observed with the aim of exploring the sensitivity of the resonance wavelength to the change of the refractive index in a nanoscale overlay. Experimental results show that the transition between cladding modes and overlay modes occurs when the refractive index of the liquid crystal (LC) overlay is changed from 1.477 to 1.515 by increasing its temperature from 20 degrees C to 65 degrees C. The spectral tuning ability of LPGs coated with a HRI LC layer by electro-optic modulation on a LC layer is also demonstrated, and the maximum tuning range can reach approximately 10 nm by choosing a highly sensitive operating point in the transition region.

Self-assembly of polymer and molybdenum oxide into lamellar hybrid materials.

We report on self-assembly of polymer and molybdenum oxide chains into a new class of lamellar hybrid materials. Aqueous ammonium molybdate and polyvinyl alcohol (PVA) or carboxymethyl cellulose (CMC) were used as the starting materials. Ammonium molybdate was hydrolyzed into layered molybdenum oxide under acidified conditions. The organic polymer chains and the inorganic molybdenum oxide layers self-assemble and pack into new hybrid composites. Scanning electron microscope (SEM) images and polarized microscopy show that these two new materials have typical lamellar structure. Transmission electron microscope (TEM) images show that the layer thickness is about 100 nm. X-ray diffraction (XRD) data confirm the formation of inorganic molybdenum oxide. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) data gave thermal behavior of these composites. The mechanism of this hybrid reaction and the templating function of polymers were discussed in this paper. A special entropy effect was discovered when polymer was used as guest species. This entropy effect makes polymers preferential candidates as guest species rather than small molecules when fabricating organic/inorganic layered hybrid materials. We believe that this opens a new way to create organic/inorganic hybrid superstructures.