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Melanocytic nevi (MN) can be classified into three subtypes according to the depth of the nests of nevus cells which is important for management. High-frequency ultrasound (HF-US) can clearly reveal the lesion size, contour, depth, and internal structures. However, the HF-US studies of MN according to subtypes are limited. We aimed to describe the HF-US features of MN and explore its value in accurate classification.This retrospective study was conducted from January 2018 to November 2019. Eighty-five patients with MN were included and examined by 50 and 20 MHz HF-US. The HF-US features were recorded including morphological flatness, depth, shape, boundary, internal echogenicity, hyperechoic spots, lateral acoustic shadow, posterior echoic patterns, mushroom signs, and straw-hat signs. Each image was evaluated by two physicians independently, and the consistency was tested.Eleven lesions could not be detected by HF-US. The rest 74 lesions underwent ultrasonic analysis. MN appeared as strip-shaped or oval, hypoechoic areas localized in the epidermis and dermis under ultrasonography. A strong consistency between HF-US and dermoscopy of determining the lesion depth was achieved (κ = 0.935, p 0.001). The hyperechoic spots were found in 57.6% intradermal nevi. The mushroom signs were seen in 34.8% intradermal nevi, and the straw-hat signs were seen in all the compound nevi.MN can be correctly classified using HF-US, and it had a strong correlation with dermoscopic and clinical classification. HF-US could further reveal the internal morphological features of MN, which may support more precise classification and management.

As emerging 2D materials, arsenene and arsenic materials have attracted rising interest in the past few years. The diverse crystalline phases, exotic electrical characteristics, and widespread applications of 2D arsenene and arsenic bring them great research value and utilization potential. Herein, the recent progress of 2D arsenene and arsenic is reviewed in terms of fundamental properties, preparation, and applications. The fundamental properties of 2D arsenene and arsenic, including the crystal phases, environmental stability, and electrical structure, from theoretical to experimental reports are first summarized. Then, the experimental processes for preparing 2D arsenene and arsenic, along with their respective advantages and disadvantages, are introduced including epitaxial growth, mechanical exfoliation, and liquid-phase exfoliation. Moreover, applications of 2D arsenene and arsenic are discussed, suggesting a wide range of applications of 2D arsenene and arsenic in field-effect transistors, sensors, catalysts, biological applications, and so on. Finally, some perspectives about the challenges and opportunities of promising 2D arsenene and arsenic are provided. This review provides a helpful guidance and stimulates more focus on future explorations and developments of 2D arsenene and arsenic.

Rechargeable silicon anode lithium ion batteries (SLIBs) have attracted tremendous attention because of their merits, including a high theoretical capacity, low working potential, and abundant natural sources. The past decade has witnessed significant developments in terms of extending the lifespan and maintaining high capacities of SLIBs. However, the detrimental issue of low initial Coulombic efficiency (ICE) toward SLIBs is causing more and more attention in recent years because ICE value is a core index in full battery design that profoundly determines the utilization of active materials and the weight of an assembled battery. Herein, a comprehensive review is presented of recent advances in solutions for improving ICE of SLIBs. From design perspectives, the strategies for boosting ICE of silicon anodes are systematically categorized into several aspects covering structure regulation, prelithiation, interfacial design, binder design, and electrolyte additives. The merits and challenges of various approaches are highlighted and discussed in detail, which provides valuable insights into the rational design and development of state-of-the-art techniques to deal with the deteriorative issue of low ICE of SLIBs. Furthermore, conclusions and future promising research prospects for lifting ICE of SLIBs are proposed at the end of the review.

A novel near-infrared (NIR)-emissive amphiphilic BODIPY derivative, BBDP, was successfully prepared and thoroughly characterized. The photophysical properties in various organic solvents and THF/H2 O mixtures with different fractions of water were investigated. BBDP self-assembled into nanofibers in a water environment owing to its amphiphilic properties. Through charge-transfer interactions, BBDP co-assembled with a perylene bisimide derivative, PBI, and a viologen derivative, MV, to generate two superamphiphiles. These two superamphiphiles were able to aggregate in water media at appropriate concentrations. The BBDP-PBI charge-transfer complex formed nanorods, whereas the BBDP-MV aggregates expressed a disk-like morphology. This research paves the way for us to manipulate the morphology of dye assemblies.

A novel compatibilizer with high grafting degree (GD%) of maleic anhydride (MA) onto liquid polybutadiene (LPB) was synthesized via a solution method, in particular, very low gel rate was produced by the synergetic effects of acetanilide and epoxy resin (EP), and the GD% was improved by adding the EP resin and acetanilide. The structure and thermal stability of the MA-grafted-liquid polybutadiene (LPB-g-MA) were characterized by acid base titrations, FTIR, and TGA techniques. The results showed that both MA and EP resin have been grafted onto the macromolecular chains of LPB with a good thermal stability. Then, it was used as compatibilizer in short aramid fiber (AF) reinforcing natural rubber (NR)/carbon black (CB). The synthetic compatibilizer (LPB-g-MA) enhanced the interfacial interaction between the fiber and the rubber matrix with a lower swelling degree and lower peak of loss factor, and the mechanical properties including tensile strength, tensile modulus 100%, tear strength and elongation at break of the final composites increased with the increase of m (E51)/m (LPB). AF and CB had a synergistic effect to reinforce the properties of NR. The dynamic stiffness of the rubber was obviously improved by the short AF, especially in the presence of the compatibilizer. POLYM. COMPOS., 2017. © 2017 Society of Plastics Engineers

Comprised of a battery anode and a supercapacitor cathode, hybrid lithium-ion capacitors (HLICs) are found to be an effective solution to realize both high power density and high energy density at the same time. Organic-inorganic hybrid materials with well-organized framework guided by the reticular chemistry are one of the promising anode materials for HLICs because of rich active sites and ordered porosity. Herein, metal-organic framework consisting of Zr4+ metal ions and tetrathiafulvalene-based ligands (Zr-MOF) is proposed as the pseudocapacitive anode of HLICs. The Zr-MOF possesses high stability, high crystallinity, and multiple meso-microporous channels favorable for ion transport. The as-prepared Zr-MOF||activated carbon HLICs present high energy density (122.5 Wh kg-1 ), high power density (12.5 kW kg-1 ), and stable cycling performance (86% capacity retention after 1000 cycles at 2000 mA g-1 ) within the operating voltage range of 1.0-4.0 V. The results expand the direct application of MOF for bridging the performance gap between batteries and supercapacitors.