A covalent organic framework (Tp-PTO-COF) with carbonyl active sites was proposed as a novel cathode material and successfully applied in aqueous rechargeable zinc-ion batteries (ZIBs).
A three dimensional (3D) porous framework-like N-doped carbon (PFNC) with a high specific surface area was successfully fabricated through ammonia doping and graphitization based on pomelo peel. The obtained PFNC exhibits an enhanced specific capacitance (260 F g(-1) at 1 A g(-1)) and superior cycling performance (capacitance retention of 84.2% after 10000 cycles at 10 A g(-1)) on account of numerous voids and pores which supply sufficient pathways for ion diffusion during cycling. Furthermore, a fabricated asymmetric PFNC//PFN device based on PFNC and porous flake-like NiO (PFN) arrays achieves a specific capacitance of 88.8 F g(-1) at 0.4 A g(-1) and an energy density of 27.75 Wh kg(-1) at a power density of 300 W kg(-1) and still retains 44 F g(-1) at 10 A g(-1) and 13.75 Wh kg(-1) at power density of 7500 W kg(-1). It is important that the device is able to supply two light-emitting diodes for 25 min, which demonstrates great application potential.
Nanopore-based sensing has emerged as a promising candidate for affordable and powerful DNA sequencing technologies. Herein, we demonstrate that nanopores can be successfully fabricated in Mg alloys via focused electron beam (e-beam) technology. Employing in situ high-resolution transmission electron microscopy techniques, we obtained unambiguous evidence that layer-by-layer growth of atomic planes at the nanopore periphery occurs when the e-beam is spread out, leading to the shrinkage and eventual disappearance of nanopores. The proposed healing process was attributed to the e-beam-induced anisotropic diffusion of Mg atoms in the vicinity of nanopore edges. A plausible diffusion mechanism that describes the observed phenomena is discussed. Our results constitute the first experimental investigation of nanopores in Mg alloys. Direct evidence of the healing process has advanced our fundamental understanding of surface science, which is of great practical importance for many technological applications, including thin film deposition and surface nanopatterning.
In situ transmission electron microscopy was used to observe the dynamic evolution of the morphology and phase transformations in CuO nanowires during the process of sodiation. Our results facilitate a fundamental understanding of the sodiation mechanism in CuO nanostructures used as electrode materials in sodium ion batteries.
Accumulating evidence demonstrates that aberrant miRNAs contribute to gastric cancer (GC) development and progression. However, the roles of various miRNAs in GC remain to be determined. In the present study, we confirmed that a reduced miR-379 expression was present in GC tissues and cell lines. Our clinical analysis revealed that the downregulated miR-379 expression was significantly correlated with poor prognostic features including lymph node metastasis and advanced TNM stage. Moreover, we confirmed that miR-379 was a novel independent prognostic marker for predicting 5-year survival of GC patients. The ectopic overexpression of miR-379 inhibited cell migration, invasion and EMT progress, while downregulated miR-379 reversed the effect. In addition, miR-379 regulated the focal adhesion kinase (FAK) by directly binding to its 3'-UTR, resulting in suppression of AKT signaling. In clinical samples of GC, miR-379 inversely correlated with FAK, which was upregulated in GC. Alteration of FAK expression or activating AKT signaling at least partially abolished the migration, invasion and EMT progress effects of miR-379 on GC cells. In conclusion, our results indicated that miR-379 functioned as a tumor suppressor gene in regulating the EMT and metastasis of GC via targeting FAK/AKT signaling, and may represent a novel potential therapeutic target and prognostic marker for GC.
In this paper, using high resolution transmission electron microscopy, we showed the fabrication of faceted nanopores with various shapes in magnesium by focused electron beam (e-beam). The characteristics of nanopore shapes and the crystallographic planes corresponding to the edges of the nanopores were discussed in detail. Interestingly, by manipulating the e-beam (e.g., irradiation direction and duration), the nanopore shape and size could be effectively controlled along different directions. Our results provide important insight into the nanopore patterning in metallic materials and are of fundamental importance concerning the relevant applications, such as nanopore-based sensor, etc.
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