Intercalation-based inorganic materials that change their colours upon ion insertion/extraction lay an important foundation for existing electrochromic technology. However, using only such inorganic ...electrochromic materials, it is very difficult to achieve the utmost goal of full-colour tunability for future electrochromic technology mainly due to the absence of structural flexibility. Herein, we demonstrate an ultracompact asymmetric Fabry-Perot (F-P) nanocavity-type electrochromic device formed by using partially reflective metal tungsten as the current collector and reflector layer simultaneously; this approach enables fairly close matching of the reflections at both interfaces of the WO
thin layer in device form, inducing a strong interference. Such an interference-enhanced device that is optically manipulated at the nanoscale displays various structural colours before coloration and, further, can change to other colours including blue, red, and yellow by changing the optical indexes (n, k) of the tungsten oxide layer through ion insertion.
This study investigates the role of circular RNA (circRNA) hsa_circ_0000515 in cervical cancer and the underlying mechanism associated with microRNA-326 (miR-326). hsa_circ_0000515 and ETS ...transcription factor ELK1 (ELK1) were initially over-expressed and miR-326 was down-regulated in cervical cancer tissues and cells. Low hsa_circ_0000515 expression was found to be associated with favorable prognosis of patients with cervical cancer. A series of mimics, inhibitors, over-expression plasmids or siRNAs were introduced into cervical cancer cells to alter the expression of hsa_circ_0000515, miR-326 and ELK1.
experiments exhibited that silencing of hsa_circ_0000515 or upregulation of miR-326 resulted in suppressed proliferation and invasion, along with induced apoptosis and autophagy of cervical cancer cells. Dual-luciferase reporter assay, RNA pull-down and RIP assays highlighted that hsa_circ_0000515 was able to act as a ceRNA of miR-326 to increase ELK1. Furthermore, enhancement of ELK1 expression resulted in enhanced proliferation and invasion but repressed apoptosis and autophagy of cervical cancer cells.
experiments further confirmed the suppressed tumor growth by hsa_circ_0000515 silencing. Our findings demonstrated that hsa_circ_0000515 acts as a tumor promoter in cervical cancer. The study provides evidence for targeting hsa_circ_0000515 for therapeutic purposes in treating cervical cancer.
Electrochromic technology has been actively researched for displays, adjustable mirrors, smart windows, and other cutting-edge applications. However, it has never been proposed to overcome the ...critical problems in the field of surface-enhanced Raman scattering (SERS). Herein, we demonstrate a generic electrochromic strategy for ensuring the reproducibility and renewability of SERS substrates, which are both scientifically and technically important due to the great need for quantitative analysis, standardized production and low cost in SERS. This color-changing strategy is based on a unique quantitative relationship between the SERS signal amplification and the coloration degree within a certain range, in which the SERS activity of the substrate can be effectively inferred by judging the degree of color change. Our results may provide a first step toward the rational design of electrochromic SERS substrates with a high sensitivity, reproducibility, and renewability.
Solitons, nonlinear self-trapped wavepackets, have been extensively studied in many and diverse branches of physics such as optics, plasmas, condensed matter physics, fluid mechanics, particle ...physics and even astrophysics. Interestingly, over the past two decades, the field of solitons and related nonlinear phenomena has been substantially advanced and enriched by research and discoveries in nonlinear optics. While optical solitons have been vigorously investigated in both spatial and temporal domains, it is now fair to say that much soliton research has been mainly driven by the work on optical spatial solitons. This is partly due to the fact that although temporal solitons as realized in fiber optic systems are fundamentally one-dimensional entities, the high dimensionality associated with their spatial counterparts has opened up altogether new scientific possibilities in soliton research. Another reason is related to the response time of the nonlinearity. Unlike temporal optical solitons, spatial solitons have been realized by employing a variety of noninstantaneous nonlinearities, ranging from the nonlinearities in photorefractive materials and liquid crystals to the nonlinearities mediated by the thermal effect, thermophoresis and the gradient force in colloidal suspensions. Such a diversity of nonlinear effects has given rise to numerous soliton phenomena that could otherwise not be envisioned, because for decades scientists were of the mindset that solitons must strictly be the exact solutions of the cubic nonlinear Schrödinger equation as established for ideal Kerr nonlinear media. As such, the discoveries of optical spatial solitons in different systems and associated new phenomena have stimulated broad interest in soliton research. In particular, the study of incoherent solitons and discrete spatial solitons in optical periodic media not only led to advances in our understanding of fundamental processes in nonlinear optics and photonics, but also had a very important impact on a variety of other disciplines in nonlinear science. In this paper, we provide a brief overview of optical spatial solitons. This review will cover a variety of issues pertaining to self-trapped waves supported by different types of nonlinearities, as well as various families of spatial solitons such as optical lattice solitons and surface solitons. Recent developments in the area of optical spatial solitons, such as 3D light bullets, subwavelength solitons, self-trapping in soft condensed matter and spatial solitons in systems with parity-time symmetry will also be discussed briefly.
CFs/g-C3N4/BiOBr bundles have been prepared, and they can be woven into recyclable cloth-shaped visible-light-driven photocatalyst for degrading TC-HCl in water.
Display omitted
•In-situ growth of ...g-C3N4/BiOBr heterojunctions on CFs.•Broad photoabsorption and high photocurrent of CFs/g-C3N4/BiOBr.•Simple weave of CFs/g-C3N4/BiOBr fibers to cloth.•High photocatalytic activity and simple recyclable process.
The photocatalytic degradation of tetracycline (TC) in water has received much attention, but its practical application in the river has been limited by a lack of efficient and recyclable visible-light-driven photocatalysts. To solve this problem, with flexible carbon fiber (CF) bundles as substrate, we have reported the in-situ growth of g-C3N4/BiOBr heterojunctions as weaveable photocatalyst. g-C3N4 nanosheets (thickness: ~30 nm, diameter: 0.4–1 μm) and BiOBr layer (thickness: ~25 nm, diameter: 200–500 nm) were grown on CFs successively. CFs/g-C3N4/BiOBr bundles could be woven into cloth (area: 5 × 5 cm2, weight: 0.15 g), and the cloth exhibited remarkably enhanced photodegradation efficiency (86.1%) for degrading TC-HCl in 120 min. In addition, h+, O2− and OH were demonstrated as the reactive species contributing to the elimination of TC-HCl. Especially, two possible pathways of degrading TC-HCl were proposed based on the intermediate products. Thus, CFs/g-C3N4/BiOBr could serve as a flexible, weaveable and recyclable photocatalyst for antibiotic elimination in an aqueous environment.
Semiconductor-mediated photocatalysis has received tremendous attention as it holds great promise to address the worldwide energy and environmental issues. To overcome the serious drawbacks of fast ...charge recombination and the limited visible-light absorption of semiconductor photocatalysts, many strategies have been developed in the past few decades and the most widely used one is to develop photocatalytic heterojunctions. This review attempts to summarize the recent progress in the rational design and fabrication of heterojunction photocatalysts, such as the semiconductor-semiconductor heterojunction, the semiconductor-metal heterojunction, the semiconductor-carbon heterojunction and the multicomponent heterojunction. The photocatalytic properties of the four junction systems are also discussed in relation to the environmental and energy applications, such as degradation of pollutants, hydrogen generation and photocatalytic disinfection. This tutorial review ends with a summary and some perspectives on the challenges and new directions in this exciting and still emerging area of research.
The design, construction, and photocatalytic performances of semiconductor heterojunction photocatalysts are briefly reviewed and selectively highlighted.
Surface-enhanced Raman spectroscopy (SERS) represents a very powerful tool for the identification of molecular species, but unfortunately it has been essentially restricted to noble metal supports ...(Au, Ag and Cu). While the application of semiconductor materials as SERS substrate would enormously widen the range of uses for this technique, the detection sensitivity has been much inferior and the achievable SERS enhancement was rather limited, thereby greatly limiting the practical applications. Here we report the employment of non-stoichiometric tungsten oxide nanostructure, sea urchin-like W18O49 nanowire, as the substrate material, to magnify the substrate-analyte molecule interaction, leading to significant magnifications in Raman spectroscopic signature. The enrichment of surface oxygen vacancy could bring additional enhancements. The detection limit concentration was as low as 10(-7) M and the maximum enhancement factor was 3.4 × 10(5), in the rank of the highest sensitivity, to our best knowledge, among semiconducting materials, even comparable to noble metals without 'hot spots'.
•A new two-dimensional Gaussian distribution model is proposed to simulate pitting distribution.•The overlaps of the pits and pits in the boundary of the tooth surface are also considered in the ...computation of TVMS.•A new method has been proposed for calculating the TVMS of two meshing gears with multiple tooth pitting.
Tooth damage often causes gear mesh stiffness to decrease. Therefore, time-varying mesh stiffness (TVMS) can reflect the health condition of gears. A new two-dimensional Gaussian distribution model is proposed to simulate pitting distribution. In the initial stage, the pitting model is built with pits satisfying a predefined two-dimensional Gaussian distribution. With the development of pitting, both the diameter and the depth of pitting dents will increase, meanwhile new pits that satisfies another two-dimensional Gaussian distribution will be generated near the existing pitting area. The overlaps of the pits and pits in the boundary of the tooth surface are also considered in the computation of TVMS. In addition, a new method has been proposed for calculating the TVMS of two meshing gears with multiple tooth surface pitting. Finally, the influence of different pitting on the TVMS has been analyzed in detail by numerical experiments. The validity of the proposed new distribution model and the method for TVMS have been successfully verified compared with the finite element model.
The porous ultrathin graphitic carbon nitride (g-C3N4) with confined surface carbon defects was obtained via the twice thermal treatment of bulk g-C3N4. The as-prepared porous ultrathin g-C3N4 sample ...displayed the average thickness of about 0.9 nm. The porous ultrathin g-C3N4 with confined surface carbon defects was designed to bidirectional acceleration of carrier separation for both the bulk and the surface. Multiple characterizations have been employed to determine the structure, morphology, surface feature, defect, and electronic structure of the obtained samples. The photocatalytic activity of the obtained porous ultrathin g-C3N4 materials was evaluated for the degradation of rhodamine B under the visible light irradiation. The structure-activity relationship of the porous ultrathin g-C3N4 materials was studied in details. The free radicals during the photocatalysis process was determined and analyzed by electron spin resonance and X-ray photoelectron spectroscopy valence band spectra technique, in which the main free radicals would be changed from superoxide radical for bulk g-C3N4 to both superoxide radical and hydroxyl radical for porous ultrathin g-C3N4. This ideal material model disclosing atomic-level insights into the role of porous ultrathin structure with confined carbon defects in the enhanced photocatalytic activity.
PDF
