2852780.mp4

Vibration tes

2852781.mp4

Respiration tes

Understanding Metal–Semiconductor Plasmonic Resonance Coupling through Surface-Enhanced Raman Scattering

Although there has been intense research on plasmon-induced charge transfer within metal/semiconductor heterostructures, previous studies have all focused on the surface plasmonic resonance (SPR) of only noble metals. Herein and for the first time, we observe and take into account the plasmonic coupling between SPR of both noble-metal and semiconductor nanostructures. A W18O49/Ag heterostructure composed of metallic Ag nanoparticles (Ag NPs) and semiconducting W18O49 nanowires (W18O49 NWs) is designed and fabricated, which exhibits a broad and strong SPR absorption in the visible wavelength range. This SPR band is attributed to the SPR coupling between the SPR of both Ag NPs and W18O49 NWs. Surface-enhanced Raman scattering (SERS) is then used to reveal the interactions between the metal SPR, semiconductor SPR, and the heterostructure’s charge transfer (CT) process, demonstrating that such coupled SPR enhanced the heterostructure’s internal CT and SERS signals. Finally, we proposed a new coupled-plasmon-induced charge transfer mechanism to interpret the improved CT efficiency between the SERS substrate and molecules. Our work provides insight for further studies on plasmonic effects and interfacial charge transfer in metal/semiconductor heterostructures

2852782.mp4

Pulse tes

Palladium-catalyzed facile synthesis of furoquinolinones and furopyridinones

<p>This work is focused on the development of a convenient and efficient approach for the synthesis of furoquinolinones and furopyridinones through palladium-catalyzed cyclization reactions between styrenes and 4-hydroxyquinolinones/4-hydroxypyridinones under air conditions. Studies conducted to evaluate the antitumoral potential of the resulted compounds revealed that some of the obtained furoquinolinones exhibited <i>in vitro</i> antiproliferative activity on human-derived stomach cancer cell lines.</p

Hepatotoxicity of <i>Eupatorium adenophorum</i> extracts and the identification of major hepatotoxic components

<p><i>Eupatorium adenophorum</i> can induce liver toxicity in animals. For the safe utilisation of the weed, the hepatotoxic components need to be discovered. In this study, <i>in vitro</i> hepatotoxicity of different extracts from <i>E. adenophorum</i> were determined on human hepatocyte cell line L02 and hepatocellular carcinoma cell line HepG2. The results showed that water extracts of <i>E. adenophorum</i> exhibited no hepatotoxicity <i>in vitro</i> while high concentrations of the organic solvent extracts had obvious hepatotoxicity. Sesquiterpenes may contribute to the toxicity based on the comparison of composition analysis. Three cadinene sesquiterpenes were purified and identified as 9-oxo-10,11-dehydroageraphorone, 10<i>Hα</i>-9-oxo-ageraphorone and 10<i>Hβ</i>-9-oxo-ageraphorone. <i>In vitro</i> hepatotoxic effects of these components were investigated, the IC₅₀ of the three compounds were 122.53, 87.52, and 108.80 μM in L02 cells and 151.92, 104.48, and 138.08 μM in HepG2 cells by Cell Counting Kit-8 (CCK-8) assay. The three components were confirmed to be, at least partial, hepatotoxic components.</p

Generation of Pronounced Resonance Profile of Charge-Transfer Contributions to Surface-Enhanced Raman Scattering

A chemically enhanced mechanism of surface-enhanced Raman scattering (SERS) was investigated using a series of metal-charge-transfer (CT) complex systems fabricated by a self-assembly method. The developed Ag/4-mercaptophenols (MPH)/<i>n</i>-TiO₂ system presented layer number-dependent SERS spectra. By using the electron density values of the Ag₁₃/MPH and Ag₁₃/MPH/TiO₂ system calculated using the density functional theory (DFT) and by using these values in combination with the results of our previous investigations on the mechanism of the Ag/MPH/TiO₂ system, the absorption threshold of the CT complexes was clearly defined. The degree of CT was selected to study the layer number-dependent SERS spectra. Based on the layer number-dependent SERS data, it has been inferred that the degree of CT represents a resonance phenomenon. In addition, the CT resonance occurs at higher energy in the Ag/MPH/<i>n</i>-TiO₂ system than in the monolayer TiO₂ system owing to the blue-shift of CT states with the continuous introduction of TiO₂. Thus, we provide a good example of the use of a CT complex system to investigate the chemical mechanism of SERS

Rapid Total Synthesis of (±)Trigonoliimine A via a Strecker/Houben–Hoesch Sequence

A novel synthetic route to the hexacyclic system of trigonoliimine A was accomplished in four steps from <i>N</i>-phthaloyl 6-OMe-tryptamine. Key reactions include a three-component Strecker-type reaction to fashion the two C–N bonds in the D ring and a subsequent Houben–Hoesch type cyclization to deliver the characteristic seven-membered C ring

Simulations agree well with FGF-2 outflow measurements.

<p>(A) FGF-2 (0.92 ng) was injected into the cartridge reservoir and then flowed through the cell-lined hollow fibers at 0.63 mL/min (1.26 mm/sec), pulsatile flow. FGF-2 collected from the exit fluid (•) is shown. Simulation results based on cells expressing 1×10⁴ FGFR/cell and 2.5×10⁵ HSPG/cell with 32% loss in the entrance reservoir having the same FGF-2 amount injected at the same flow rate (○) are also shown. (B) Similar outflow FGF-2 measurements are shown following FGF-2 (0.92 ng) addition for heparinase-treated (experimental - •) and simulation results with out HSPG (simulations - ○). Simulations were run with cells expressing 1×10⁴ FGFR/cell and 30% loss in the entrance reservoir.</p

Long-Range Surface Plasmon Field-Enhanced Raman Scattering Spectroscopy Based on Evanescent Field Excitation

The purpose of this paper is to enhance Raman signals in the evanescent field by using the excitation of long-range surface plasmons (LRSPs). A four-phase Kretschmann LRSP resonance (LRSPR) setup composed of a K9 prism/MgF₂ film/silver film/water configuration was constructed. Incident angle-dependent surface-enhanced Raman scattering (SERS) spectra were measured in the evanescent field on this four-phase configuration. The SERS signal obtained under the evanescent field excitation at the LRSPR angle was 15 times higher than that collected based on the conventional SPR configuration. The experimental result also proved that the LRSPs in this evanescent field-enhanced SERS spectroscopy possessed at least 500 nm in the electric field penetration depth, which is longer than the electric field penetration depth of conventional surface plasmons