10 research outputs found

    A late Neoarchaean–early Palaeoproterozoic crustal thickening event in the eastern North China Craton: petrological and geochronological evidence from Eastern Hebei terrane

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    <p>Determining an age framework for Precambrian crystalline rocks and associated granulite-facies metamorphism of the inner blocks in the North China Craton (NCC) is important for determining the tectonic setting and evolution of the craton during the Neoarchaean–Palaeoproterozoic. The Eastern Hebei terrane (EHT), located in the Eastern Block of the NCC, is composed of tonalitic-trondhjemitic-granodioritic (TTG) gneisses and potassium-rich granitoids, along with rafts of supracrustal rocks that are intruded by basic dikes. TTG gneisses in the EHT yield crystallization ages of 2516–2527 Ma. The oldest age of inherited zircons from a mylonitic TTG gneiss is ~2918 Ma. Granulite-facies supracrustal metamorphic rocks in the Zunhua high-grade meta-greenstone belt indicate an andesitic/basaltic protolith that was formed at ~2498 Ma. A syn-deformational granite in the Jinchangyu greenschist-facies shear zone yields a crystallization age of ~2474 Ma. Metamorphism of the supracrustal rocks and mylonitic greenschist took place at ~2461 and ~2475 Ma, respectively. Rare earth elements (REE) patterns and slightly negative Nb and Ta anomalies indicate that the magmatic precursors of the supracrustal rocks might be derived from partial melting of a sub-arc mantle wedge and metasomatized by fluids derived from a subducting slab. These rocks plot in the island arc basalts (IAB) field on a La/Nb vs. La diagram, further supporting this interpretation. The microstructures of a garnet–two-pyroxene granulite indicate an approximately clockwise P-T path. The crystallization ages of the TTG gneisses represent periods of the major crustal growth in the NCC, and the granulite- and greenschist-facies metamorphism indicates an orogenic event that involved crustal thickening at ~2.47 Ga.</p

    Anodic Oxidation in Aluminum Electrode by Using Hydrated Amorphous Aluminum Oxide Film as Solid Electrolyte under High Electric Field

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    Dense and nonporous amorphous aluminum oxide (AmAO) film was deposited onto platinized silicon substrate by sol–gel and spin coating technology. The evaporated aluminum film was deposited onto the AmAO film as top electrode. The hydrated AmAO film was utilized as a solid electrolyte for anodic oxidation of the aluminum electrode (Al) film under high electric field. The hydrated AmAO film was a high efficiency electrolyte, where a 45 nm thick Al film was anodized completely on a 210 nm thick hydrated AmAO film. The current–voltage (<i>I</i>–<i>V</i>) characteristics and breakdown phenomena of a dry and hydrated 210 nm thick AmAO film with a 150 nm thick Al electrode pad were studied in this work. Breakdown voltage of the dry and hydrated 210 nm thick AmAO film were 85 ± 3 V (405 ± 14 MV m<sup>–1</sup>) and 160 ± 5 V (762 ± 24 MV m<sup>–1</sup>), respectively. The breakdown voltage of the hydrated AmAO film increased about twice, owing to the self-healing behavior (anodic oxidation reaction). As an intuitive phenomenon of the self-healing behavior, priority anodic oxidation phenomena was observed in a 210 nm thick hydrated AmAO film with a 65 nm thick Al electrode pad. The results suggested that self-healing behavior (anodic oxidation reaction) was occurring nearby the defect regions of the films during <i>I</i>–<i>V</i> test. It was an effective electrical self-healing method, which would be able to extend to many other simple and complex oxide dielectrics and various composite structures

    A new azadirachta from the crude extracts of neem (<i>Azadirachta Indica</i> A. Juss) seeds

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    <p>One new compound, 2H, 3H-cyclopent[b] furo [2′,3′:4,5] naphtho [2,4-d] heptlactone-[3,7] furan-6aceticacid, 3-(acetyloxy)-8-(3-furyl)-2a, 4a, 4b, 4c,5,5a, 6, 6a, 8, 9,9a, 10a,10b-13 hydrogen-2a,5a,6a,5-tetramethyl-3-[[(2E)-2-methyl-1-oxo-2-butenyl]oxy]-methyl ester, named azadirachta R (<b>1</b>), along with 10 known ones, Azadirachta A, AZ-B, AZ-D, AZ-H, AZ-I, nimbin, deacetylnimbin, salannin, deacetylsalannin and azadiradione were isolated from the crude extracts of neem (<i>Azadirachta indica</i> A. Juss) seeds, which were determined by UV, IR, HR-ESI–MS and NMR data analyses. According to the <i>in vitro</i> antibacterial activity experimental results, this compound showed good antibacterial activity to two bacteria, the minimum inhibitory concentration and the minimum bactericidal concentration of compound <b>1</b> to two kinds of bacteria are 50 and 25 mg/L, respectively, which were determined by resazurin colour-micro-dilution method. The experimental results provide a theoretical basis for the comprehensive utilisation of azadirachtin compounds in the future.</p

    One-Step Preparation and Assembly of Aqueous Colloidal CdS<sub><i>x</i></sub>Se<sub>1–<i>x</i></sub> Nanocrystals within Mesoporous TiO<sub>2</sub> Films for Quantum Dot-Sensitized Solar Cells

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    In the field of quantum dots (QDs)-sensitized solar cells, semiconductor QDs sensitizer with a moderate band gap is required in order to sufficiently match the solar spectrum and achieve efficient charge separation. At present, changing the size of QDs is the main method used for adjusting their band gap through quantum size effect, however, the pore sizes of mesoporous TiO<sub>2</sub> film set a limit on the allowed size of QDs. Therefore, the tuning of electronic and optical properties by changing the particle size could be limited under some circumstances. In this paper, high-quality aqueous CdS<sub><i>x</i></sub>Se<sub>1–<i>x</i></sub> QDs sensitizer is successfully synthesized and effectively deposited on a mesoporous TiO<sub>2</sub> film by a one-step hydrothermal method. In addition to size, alloy QDs provide composition as an additional dimension for tailoring their electronic properties. The alloy composition and band gap can be precisely controlled by tuning the precursor (Se/Na<sub>2</sub>S·9H<sub>2</sub>O) ratio while maintaining the similar particle size. By using such CdS<sub><i>x</i></sub>Se<sub>1–<i>x</i></sub> sensitized TiO<sub>2</sub> films as photoanodes for solar cell, a maximum power conversion efficiency of 2.23% is achieved under one sun illumination (AM 1.5 G, 100 mW cm<sup>–2</sup>)

    Controllable Fabrication of Noniridescent Microshaped Photonic Crystal Assemblies by Dynamic Three-Phase Contact Line Behaviors on Superhydrophobic Substrates

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    Enormous research efforts have been made to self-assemble monodisperse colloidal spheres into special microscopic shapes (e.g., superbeads, superballs, or doughnuts), due to their widespread applications in sensors, displays, separation processes, catalysis, etc. But realization of photonic crystal (PC) assemblies with both facile microshape control and a noniridescent property is still a tough task. Herein, we demonstrate the controllable fabrication of noniridescent microshaped PC assemblies by evaporation-induced self-assembly inside aqueous colloidal dispersion droplet templates on superhydrophobic substrates. The microshapes of the PC assemblies could be tuned from microbeads to microwells to microellipsoids by manipulating the dynamic behaviors of the three-phase contact line of the colloidal droplets during the evaporating process. Structure characterization shows that the PC assemblies are crack-free, consisting of an ordered periodic arrangement of colloidal spheres in the surface layers and amorphous inner layers. The incorporation of black Fe<sub>3</sub>O<sub>4</sub> nanoparticles into the PC assembly lattice is demonstrated to endow the PC assemblies with enhanced noniridescent structural colors with wide-viewing angles and a superparamagnetic property. The crack-free noniridescent PC assemblies with controlled microshapes have promising applications in the fields of nontoxic, nonbleaching pigments and energy-efficient full-color display pixels, and their facile fabrication procedure may provide guidance for creating new types of substructured colloidal particles

    Presentation1_Poor prognosis, hypomethylation, and immune infiltrates are associated with downregulation of INMT in head and neck squamous cell carcinoma.pdf

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    Background: Indiolethylamine-N-methyltransferase (INMT) is a methyltransferase responsible for transferring methyl groups from methyl donor SAM to its substrate. S-adenosyl-l-methionine (SAM), obtained from the methionine cycle, is a naturally occurring sulfonium compound that is vital to cellular metabolism. The expression of INMT is down-regulated in many tumorous tissues, and it may contribute to tumor invasion and metastasis. Nevertheless, the expression of INMT and its relationship to methylation and immune infiltrates in head and neck squamous cell carcinoma (HNSC) remains a mystery. Thus, we evaluated expression, clinicopathological features, prognosis, several critical pathways, DNA methylation, and immune cell infiltration for the first time.Methods: Analysis of the clinicopathological characteristics of INMT expression, several tumor-related bioinformatics databases were utilized. In addition, the role of INMT expression was analyzed for prognosis. Several INMT-related pathways were enriched on the LinkedOmics website. In addition, we have analyzed the methylation of INMT in HNSC in detail by using several methylation databases. Lastly, the relationship between INMT gene expression and immune infiltration was analyzed with ssGSEA, Timer, and TISIDB.Results: In HNSC, mRNA and protein levels were significantly lower than in normal tissues. The low expression of INMT was statistically associated with T stage, histological grade, gender, smoking history, and alcohol consumption. HNSC patients with low INMT expression have a poorer OS (overall survival) compared to those with high levels of expression. In addition, the multivariate analysis revealed INMT expression to be a remarkable independent predictor of prognosis in HNSC patients. An analysis of gene enrichment showed that several pathways were enriched in INMT, including the Ras signaling pathway, the cGMP-PKG signaling pathway, and others. Moreover, methylation patterns of INMT detected in a variety of methylation databases are closely associated with mRNA expression and prognosis. Finally, INMT was significantly correlated with immune infiltration levels.Conclusion: HNSC with low levels of INMT exhibits poor survival, hypomethylation, and immune infiltration. For HNSC, this study presented evidence that INMT is both a biomarker of poor prognosis and a target of immunotherapy.</p

    Peptide-Decorated Gold Nanoparticles as Functional Nano-Capping Agent of Mesoporous Silica Container for Targeting Drug Delivery

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    A stimuli-responsive drug delivery system (DDS) with bioactive surface is constructed by end-capping mesoporous silica nanoparticles (MSNs) with functional peptide-coated gold nanoparticles (GNPs). MSNs are first functionalized with acid-labile α-amide-β-carboxyl groups to carry negative charges, and then capped with positively charged GNPs that are decorated with oligo-lysine-containing peptide. The resulting hybrid delivery system exhibits endo/lysosomal pH triggered drug release, and the incorporation of RGD peptide facilitates targeting delivery to α<sub>v</sub>β<sub>3</sub> integrin overexpressing cancer cells. The system can serve as a platform for preparing diversified multifunctional nanocomposites using various functional inorganic nanoparticles and bioactive peptides

    Adhesion of Microdroplets on Water-Repellent Surfaces toward the Prevention of Surface Fouling and Pathogen Spreading by Respiratory Droplets

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    Biofouling caused by the adhesion of respiratory microdroplets generated in sneezing and coughing plays an important role in the spread of many infectious diseases. Although water-repellent surfaces are widely used for the long-term repellency of aqueous solutions, their repellency to pathogen-containing microdroplets is elusive. In this work, microdroplets from picoliter to nanoliter were successfully generated in a controlled manner to mimic the exhaled microdroplets in sneezing and coughing, which allowed us to evaluate the adhesion of microdroplets on both superhydrophobic and lubricant-infused “slippery” surfaces for the first time. The impact and retention of water microdroplets on the two water-repellent surfaces are compared and investigated. Microdroplet-mediated surface biofouling and pathogen transmission were also demonstrated. Our results suggested that the adhesion of microdroplets should be duly considered in the design and application of water-repellent surfaces on biofouling prevention

    Development of “Liquid-like” Copolymer Nanocoatings for Reactive Oil-Repellent Surface

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    Here, we describe a simple method to prepare oil-repellent surfaces with inherent reactivity. Liquid-like copolymers with pendant reactive groups are covalently immobilized onto substrates <i>via</i> a sequential layer-by-layer method. The stable and transparent nanocoatings showed oil repellency to a broad range of organic liquids even in the presence of reactive sites. Functional molecules could be covalently immobilized onto the oil-repellent surfaces. Moreover, the liquid repellency can be maintained or finely tailored after post-chemical modification <i>via</i> synergically tailoring the film thickness, selection of capping molecules, and labeling degree of the capping molecules. Oil-repellent surfaces that are capable of post-functionalization would have technical implications in surface coatings, membrane separation, and biomedical and analytical technologies
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