In this article, a structure based on one-dimensional photonic crystals that can be used for both angle sensing and refractive index sensing is proposed, which is achieved by optical Tamm state. ...Under Bragg scattering, its features are investigated by the transfer matrix method. This sensing structure is based on a multi-frequency absorption structure, which can achieve an absorption rate higher than 0.9 for three to four frequency points at the same time. The studied results demonstrate that the absorption peaks of such an absorption structure can be changed from three to four by adjusting the number of periods and silver layer thickness. Absorption peaks can occur red and blue shifts employing tailoring the thickness of defect and the angle of the incident light. By altering the thickness of the defect and the number of periods, the interval between the absorption peaks can be dominated. They are all with high-quality factors and can be used to bring about a high absorption sensor for the refractive index or angle. When it acts as a refractive index sensor, the operating range can cover from 2 to 2.7, whose sensitivity and average figure of merit are 32.3 THz/RIU and 100. If the presented device is used as an angle sensor, those values will become 0.5 THz/degree and 1.2, and its measuring range is from 25° to 70°. It can be said that the emergence of this special sensing structure will be possible to have a broad application prospect in the field of measurement.
Covalent organic frameworks (COFs) represent a new family of porous polymers with highly ordered two or three-dimensional channels. Although numerous studies have been focused on the design and ...synthesis of COF in the form of powders, the development of COF-based separation membranes is still hampered by the challenges of COF particles agglomeration and harsh synthetic conditions. In this work, interfacial polymerization (IP) directly performed on polymeric substrates as employed in the traditional IP process of polyamide (PA) membranes is developed for the synthesis of COF-based membranes. With the moderate reaction rate between monomer pairs in corresponding aqueous and organic solutions, a conformal growth of COF crystallites directly composited with the polysulfone (PSF) ultrafiltration substrates can be realized within 1 min. The synthesis parameters including reaction time and precursor concentrations are optimized, and thus-synthesized COF/PSF membrane presents a stable rejection to dye (Congo red) of 99.5% with a high water permeance of up to 50 L m−2 h−1 bar−1, which is 2–10 times higher than that of many other membranes with similar rejection. This convenient IP process is expected to facilitate the up-scaling and real-world applications of COF-based membranes.
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•COF-based membrane has been directly synthesized on polymeric substrates by IP.•TpPa amount is the critical factor to the performance of TpPa/PSF membrane.•TpPa/PSF membrane can effectively remove dye with a size above 1.5 nm from water.•The IP process is expected to facilitate the up-scaling of COF-based membranes.
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•Circular RNAs in human HCC were identified using RNA-sequencing.•Circular RNA cSMARCA5 was downregulated in HCC and associated with poor prognosis.•Downregulation of cSMARCA5 in HCC ...was attributed to the upregulation of DHX9.•cSMARCA5 inhibited HCC growth and metastasis both in vitro and in vivo.•cSMARCA5 acted as the sponge of miR-17-3p and miR-181b-5p to upregulate TIMP3.
In recent years, circular RNAs (circRNAs) have been shown to have critical regulatory roles in cancer biology. However, the contributions of circRNAs to hepatocellular carcinoma (HCC) remain largely unknown.
cSMARCA5 (a circRNA derived from exons 15 and 16 of the SMARCA5 gene, hsa_circ_0001445) was identified by RNA-sequencing and validated by quantitative reverse transcription PCR. The role of cSMARCA5 in HCC progression was assessed both in vitro and in vivo. circRNAs in vivo precipitation, luciferase reporter assay, biotin-coupled microRNA capture and fluorescence in situ hybridization were conducted to evaluate the interaction between cSMARCA5 and miR-17-3p/miR-181b-5p.
The expression of cSMARCA5 was lower in HCC tissues, because of the regulation of DExH-Box Helicase 9, an abundant nuclear RNA helicase. The downregulation of cSMARCA5 in HCC was significantly correlated with aggressive characteristics and served as an independent risk factor for overall survival and recurrence-free survival in patients with HCC after hepatectomy. Our in vivo and in vitro data indicated that cSMARCA5 inhibits the proliferation and migration of HCC cells. Mechanistically, we found that cSMARCA5 could promote the expression of TIMP3, a well-known tumor suppressor, by sponging miR-17-3p and miR-181b-5p.
These results reveal an important role of cSMARCA5 in the growth and metastasis of HCC and provide a fresh perspective on circRNAs in HCC progression.
Herein, we studied the role of cSMARCA5, a circular RNA, in hepatocellular carcinoma. Our in vitro and in vivo data showed that cSMARCA5 inhibits the growth and migration of hepatocellular carcinoma cells, making it a potential therapeutic target.
The increasing demands for optical anti-counterfeiting technology require the development of versatile luminescent materials with multiple models and tunable photoluminescence. Herein, the ...combination of luminescent perovskite nanocrystals and lanthanide-based metal–organic frameworks (Ln-MOFs) has been developed to offer such a high-tech anti-counterfeiting solution. The hybrid materials have been fabricated via the encapsulation of perovskite CH3NH3PbBr3 nanocrystals in europium-based metal–organic frameworks (Eu-MOFs) and they display multistage anti-counterfeiting behavior. CH3NH3PbBr3@Eu-MOF hybrids were developed in a two-step process, where the PbBr2@Eu-MOF precursor was formed first and, then, the composites can be formed quickly by the addition of CH3NH3Br into the precursors. Accordingly, the hybrid composites exhibited both excitation wavelength and temperature-dependent luminescence properties in the form of powders or films. Furthermore, the photoluminescence of the CH3NH3PbBr3@Eu-MOF composites can be quenched and recovered through water immersion and CH3NH3Br conversion, and the anti-counterfeiting applications have also been discussed. Therefore, this finding will open the opportunity to fabricate the hybrid materials with controlled photoluminescence properties, and it also acts as the emerging anti-counterfeiting materials in versatile fields.
We summarize our ongoing research endeavors to explore and discover porous MOFs for gas separation and purification.
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•Our ongoing research endeavors to explore and discover porous ...MOFs for gas separation and purification are summarized.•Some of our breakthroughs on porous MOFs for gas separation and purification are described.•Strategies for pore and function engineering are discussed.
As a new generation of porous materials, metal–organic frameworks (MOFs, also known as porous coordination polymers) have shown great promise for gas separation and purification because of their unique pore structures and surfaces for their differential recognition of small gas molecules. In this review article, we summarize our ongoing research endeavors to explore and discover microporous MOFs for gas separation and purification. We have developed several approaches to systematically tune the pores and to immobilize functional sites, including (1) the primitive cubic net of interpenetrated microporous MOFs from the self-assembly of the paddle-wheel clusters, M2(CO2)4 (M = Cu2+, Zn2+…), with two types of organic dicarboxylic acid and pillar bidentate linkers; (2) microporous mixed-metal–organic frameworks (M′MOFs) through the metallo-ligands, and (3) microporous MOFs with dual functionalities. Such efforts have enabled us to make some breakthroughs on microporous MOFs for gas separation and purification, as demonstrated in the gas chromatographic separation of hexane isomers, kinetic D2/H2 separation, acetylene/ethylene separation, carbon dioxide capture, C2H2/CO2 and C3H4/C3H6 separation. Our group is one of the first groups who have envisioned the practical promise of microporous MOFs for the industrial gas separation and examined their separation capacities and efficiency using the fixed-bed adsorption and/or breakthrough experiments. Some of the very important and representative examples of these microporous MOFs for diverse gas separation and purification are highlighted in this review.
Tumor cells with stemness (stem‐cell) features contribute to initiation and progression of hepatocellular carcinoma (HCC), but involvement of long noncoding RNAs (lncRNAs) remains largely unclear. ...Genome‐wide analyses were applied to identify tumor‐associated lncRNA‐DANCR. DANCR expression level and prognostic values of DANCR were assayed in two HCC cohorts (China and Korea, n = 135 and 223). Artificial modulation of DANCR (down‐ and overexpression) was done to explore the role of DANCR in tumorigenesis and colonization, and tumor‐bearing mice were used to determine therapeutic effects. We found that lncRNA‐DANCR is overexpressed in stem‐like HCC cells, and this can serve as a prognostic biomarker for HCC patients. Experiments showed that DANCR markedly increased stemness features of HCC cells to promote tumorigenesis and intra‐/extrahepatic tumor colonization. Conversely, DANCR knockdown attenuated the stem‐cell properties and in vivo interference with DANCR action led to decreased tumor cell vitality, tumor shrinkage, and improved mouse survival. Additionally, we found that the role of DANCR relied largely on an association with, and regulation of, CTNNB1. Association of DANCR with CTNNB1 blocked the repressing effect of microRNA (miR)−214, miR‐320a, and miR‐199a on CTNNB1. This observation was confirmed in vivo, suggesting a novel mechanism of tumorigenesis involving lncRNAs, messenger RNAs, and microRNAs. Conclusions: These studies reveal a significance and mechanism of DANCR action in increasing stemness features and offer a potential prognostic marker and a therapeutic target for HCC. (Hepatology 2016;63:499–511)
Defects play important roles in semiconductor photocatalysis, which not only can act as active sites but also serve as recombination centers for electrons and holes. The rational control of defects ...appears to be particularly important. Defect engineering in semiconductor electron-hole separation is complex but vital for photocatalysis, and the exact control of defects still presents a great challenge. This review endeavors to clarify the inherent functionality of different defects such as bulk defects and surface/interface defects. The common defects such as oxygen vacancies and M
n
+
defects have been summarized and discussed. The controllable creation of defects could lead to defect channels
via
defect-strain coupling, defect-defect and defect-electron interactions, which contribute to the enhancement in electronic conductivity and the separation of photogenerated electron-hole pairs. The deep understanding of defects can consolidate the fundamental photocatalytic theory and provide new insights for rationally designing defect-engineered semiconductor photocatalytic materials with satisfactory performance.
This review summarizes the inherent functionality of bulk, surface and interface defects, and their contributions towards mediating electron-hole separation in semiconductor photocatalysis.
► The apparent multifractality can be decomposed quantitatively. ► There is a marked finite-size effect in the detection of multifractality. ► The effective multifractality can be further decomposed ...into two components. ► A time series exhibits effective multifractality only if it possesses nonlinearity. ► The daily DJIA volatility is analyzed as an example.
Many financial variables are found to exhibit multifractal nature, which is usually attributed to the influence of temporal correlations and fat-tailedness in the probability distribution (PDF). Based on the partition function approach of multifractal analysis, we show that there is a marked finite-size effect in the detection of multifractality, and the effective multifractality is the apparent multifractality after removing the finite-size effect. We find that the effective multifractality can be further decomposed into two components, the PDF component and the nonlinearity component. Referring to the normal distribution, we can determine the PDF component by comparing the effective multifractality of the original time series and the surrogate data that have a normal distribution and keep the same linear and nonlinear correlations as the original data. We demonstrate our method by taking the daily volatility data of Dow Jones Industrial Average from 26 May 1896 to 27 April 2007 as an example. Extensive numerical experiments show that a time series exhibits effective multifractality only if it possesses nonlinearity and the PDF has an impact on the effective multifractality only when the time series possesses nonlinearity. Our method can also be applied to judge the presence of multifractality and determine its components of multifractal time series in other complex systems.
We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor–acceptor (EDA) complexes with a variety of radical precursors. Excitation ...with visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The modular nature of the commercially available xanthogenate and dithiocarbamate anion organocatalysts offers a versatile EDA complex catalytic platform for developing mechanistically distinct radical reactions, encompassing redox-neutral and net-reductive processes. Mechanistic investigations, by means of quantum yield determination, established that a closed catalytic cycle is operational for all of the developed radical processes, highlighting the ability of the organic catalysts to turn over and iteratively drive every catalytic cycle. We also demonstrate how the catalysts’ stability and the method’s high functional group tolerance could be advantageous for the direct radical functionalization of abundant functional groups, including aliphatic carboxylic acids and amines, and for applications in the late-stage elaboration of biorelevant compounds and enantioselective radical catalysis.
Perovskite oxides have substantial role in the sustainable energy delivery as reflected by their applicability as oxygen-transporting membranes (OTMs), as electrode/electrolyte components in solid ...oxide fuel cells (SOFCs), and as OTM-based reactors. These applications represent three major directions that enable the membrane-based oxy-fuel combustion technology, the clean and efficient chemical to electrical energy conversion, and the production of higher value-added chemicals from lower value raw materials. The attractiveness of perovskite oxides arises from the possibility to incorporate different A-site and B-site metal elements into their ABO3-δ lattice to form essentially A1-xA’xB1-yB’yO3-δ compound which allows tailoring of the oxygen non-stoichiometry (and thus the oxygen ionic conductivity), the oxygen reduction reaction activity, and the electronic conductivity to fit a particular application. This paper reviews the basic aspects and progresses in these three directions. The advantages and limitations of perovskites in each application are highlighted and discussed as well as the pertaining aspects.
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