Continuous Synthesis of Ag/TiO 2

A facile and environmental friendly synthesis strategy based on pulsed laser ablation has been developed for potential mass production of Ag-loaded TiO2 (Ag/TiO2) nanoparticles. By sequentially irradiating titanium and silver target substrates, respectively, with the same 1064 nm 100 ns fiber laser, Ag/TiO2 particles can be fabricated. A postannealing process leads to the crystallization of TiO2 to anatase phase with high photocatalytic activity. The phase composition, microstructure, and surface state of the elaborated Ag/TiO2 are characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) techniques. The results suggest that the presence of silver clusters deposited on the surface of TiO2 nanoparticles. The nanostructure is formed through laser interaction with materials. Photocatalytic activity evaluation shows that silver clusters could significantly enhance the photocatalytic activity of TiO2 in degradation of methylene blue (MB) under UV light irradiation, which is attributed to the efficient electron traps by Ag clusters. Our developed Ag/TiO2 nanoparticles synthesized via a straightforward, continuous, and green pathway could have great potential applications in photocatalysis

Orphan Nuclear Receptor Nur77 Inhibits Cardiac Hypertrophic Response to Beta-Adrenergic Stimulation.

The orphan nuclear receptor Nur77 plays critical roles in cardiovascular diseases, and its expression is markedly induced in the heart after beta-adrenergic receptor (β-AR) activation. However, the functional significance of Nur77 in β-AR signaling in the heart remains unclear. By using Northern blot, Western blot, and immunofluorescent staining assays, we showed that Nur77 expression was markedly upregulated in cardiomyocytes in response to multiple hypertrophic stimuli, including isoproterenol (ISO), phenylephrine (PE), and endothelin-1 (ET-1). In a time- and dose-dependent manner, ISO increases Nur77 expression in the nuclei of cardiomyocytes. Overexpression of Nur77 markedly inhibited ISO-induced cardiac hypertrophy by inducing nuclear translocation of Nur77 in cardiomyocytes. Furthermore, cardiac overexpression of Nur77 by intramyocardial injection of Ad-Nur77 substantially inhibited cardiac hypertrophy and ameliorated cardiac dysfunction after chronic infusion of ISO in mice. Mechanistically, we demonstrated that Nur77 functionally interacts with NFATc3 and GATA4 and inhibits their transcriptional activities, which are critical for the development of cardiac hypertrophy. These results demonstrate for the first time that Nur77 is a novel negative regulator for the β-AR-induced cardiac hypertrophy through inhibiting the NFATc3 and GATA4 transcriptional pathways. Targeting Nur77 may represent a potentially novel therapeutic strategy for preventing cardiac hypertrophy and heart failure

Formic acid as a hydrogen source for the iridium-catalyzed reductive amination of levulinic acid and 2-formylbenzoic acid

International audienc

Iridium Catalyzed Hydrogenation and Dehydrogenation of N-Heterocycles in Water under Mild Conditions

International audienceAn efficient catalytic method is presented for the hydrogenation of N-heterocycles. The iridium-based catalyst operates under mild conditions in water without any co-catalyst or stoichiometric additives. The catalyst also promotes the reverse reaction of dehydrogenation of N-heterocycles, hence displaying appropriate characteristics for a future hydrogen economy based on liquid organic hydrogen carriers (LOHCs)

Quantitative Calculation of Aquifer Water Quantity Using TEM Data

Mine water is a menace to coal mining. Mine water quantity is generally detected by drilling in the coal mine roadway, and the disadvantage is high workload and low efficiency. Therefore, transient electromagnetic method (TEM) was proposed, and TEM data was processed to detect the water yield property of a targeted layer in coal mine. Through a mine-oriented 3D Transient Electromagnetic Method observing system, the signal of induced voltage is obtainable. Transient Electromagnetic Method 3D data volume can be calculated through the calculation of all-time resistivity and time-depth conversion. After an appropriate apparent resistivity value is set, the spatial distribution range of an aquifer can be determined. Then, with water-filling coefficient of the aquifer, its water quantity can be estimated. The water yield property detection results in the No.4 coal seam goaf of the No.80101 workface in Jude Mine of Shanxi, China, demonstrates that the apparent resistivity of this goaf is less than 3 Ω.m, and the projection area of low-resistivity anomaly zone is 22,383 m2. By using the formula Q=KMS, we can estimate that the water volume is 33,574 m3. Three boreholes have been constructed for the later dredging and drainage project, which results in a total water yield of 33,089 m3. The error percentage of the predicted water quantity is less than 1.5%. It can thus be concluded that it is feasible to predict aquifer water content with TEM data

SiC Heterojunction Trench MOSFET with a Buried P-Type Pillar for the Low Gate-Drain Charge and Switching Loss

A novel Silicon-Carbide heterojunction U-MOSFET embedded a P-type pillar buried in the drift layer (BP-TMOS) is proposed and simulated in this study. When functioning in the on state, the merged heterojunction structure will control the parasitic body diode, and the switching loss will decrease. Moreover, to lighten the electric field on the gate oxide corner, a high-doped L-shaped P+ layer near the heterojunction beneath the gate oxide was introduced; thus, the gate oxide reliability improved. A p-type pillar is introduced in the drift layer. The p-type pillar can assistant the drift layer to deplete. Thus, the specific on-resistance for BP-TMOS can be reduced with an increase in the N-drift region’s doping concentration. Compared to the traditional SiC MOSFET (C-TMOS), the specific on-resistance decreased by 20.4%, and the breakdown voltage increased by 53.7% for BP-TMOS, respectively. Meanwhile the device exhibits a 55% decrease and a 69.7% decrease for the switching loss and gate to drain charge

Cálculo cuantitativo del volumen de aguas subterráneas a través del Método Electromagnético Transitorio (TEM)

Mine water is a menace to coal mining. Mine water quantity is generally detected by drilling in the coal mine roadway, and the disadvantage is high workload and low efficiency. Therefore, transient electromagnetic method (TEM) was proposed, and TEM data was processed to detect the water yield property of a targeted layer in coal mine. Through a mine-oriented 3D Transient Electromagnetic Method observing system, the signal of induced voltage is obtainable. Transient Electromagnetic Method 3D data volume can be calculated through the calculation of all-time resistivity and time-depth conversion. After an appropriate apparent resistivity value is set, the spatial distribution range of an aquifer can be determined. Then, with water-filling coefficient of the aquifer, its water quantity can be estimated. The water yield property detection results in the No.4 coal seam goaf of the No.80101 workface in Jude Mine of Shanxi, China, demonstrates that the apparent resistivity of this goaf is less than 3 Ω.m, and the projection area of low-resistivity anomaly zone is 22,383 m2. By using the formula Q=KMS, we can estimate that the water volume is 33,574 m3. Three boreholes have been constructed for the later dredging and drainage project, which results in a total water yield of 33,089 m3. The error percentage of the predicted water quantity is less than 1.5%. It can thus be concluded that it is feasible to predict aquifer water content with TEM data.El agua al interior de las minas es una amenaza para la minería de carbón. La cantidad del agua en las minas se detecta al perforar en las vías del socavón, con la desventaja de la carga de trabajo y la baja eficacia que significan. Por esto, el presente trabajo propone el Método Electromagnético Transitorio (TEM, del inglés Transient Electromagnetic Method) y utiliza la información generada para detectar las propiedades de producción de agua en una capa específica de una mina de carbón. A través de un sistema de observación tridimensional TEM orientado a minas se puede obtener la señal del voltaje inducido. La capacidad de la información del sistema TEM tridimensional se puede calcular al obtener la resistividad y la conversión tiempo-profundidad. Tan pronto se establece el valor apropiado de la resistividad aparente se puede determinar el rango de distribución de un acuífero. Luego, con el coeficiente de saturación del acuífero se puede calcular la cantidad de agua. Los resultados de la detección de las propiedades de producción de agua en la mina abandonada número cuatro de frente de trabajo número 80101 de la mina Jude, en Shanxi, China, demostró que la resistividad aparente de esta excavación es de 3 Ω.m, y el área de proyección de la zona anómala de baja resistividad es 22.383 m2. Al usar la fórmula Q=KMS, se estimó que el volumen de agua es de 33,574 m3. Tres pozos se han construido para el próximo proyecto de dragado y drenaje, cuyos resultados de producción de agua es de 33,089 m3. El porcentaje de error de la predicción de la cantidad de agua es menor al 1.5 %. Se concluye, por ende, que es factible producir el contenido de agua de un acuífero con la información del TEM

Selective and Efficient Iridium Catalyst for the Reductive Amination of Levulinic Acid into Pyrrolidones

International audienceThe catalytic reductive amination of levulinic acid (LA) into pyrrolidones with an iridium catalyst using H2 as hydrogen source is reported. The chemoselective iridium catalyst displayed high efficiency for the synthesis of a variety of N-substituted 5-methyl-2-pyrrolidones and N-arylisoindolinones. N-Substituted 5-methyl-2-pyrrolidone was evaluated as a bio-sourced substitute solvent to NMP (N-Methyl-pyrrolidone) in the catalytic arylation of 2-phenylpyridine