3,621 research outputs found

    Electrical and ferroelectric properties of rare-earth-doped Na0.5Bi4.0RE0.5Ti4O15 (RE = Eu, Gd and Dy) thin films

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    A study of the structural, electrical and ferroelectric properties of layered Aurivillius-type Na0.5Bi4.5Ti4O15 (NaBTi) and Na0.5Bi4.0RE0.5Ti4O15 (RE = Eu, Gd and Dy) thin films is reported. These films were fabricated on Pt-coated Si(100) substrates by using a chemical solution deposition method followed by a heat treatment. The rare-earth elements used as dopants, such as Eu, Gd and Dy, were found to be effective in improving the leakage current densities and the ferroelectric properties of the layered Na0.5Bi4.5Ti4O15 thin films without affecting their original Aurivillius structures. Based on the measured ferroelectric polarization-electric field (P−E) hysteresis loops, we found that the Gd-doped NaBTi thin film, among all the films, exhibited the highest ferroelectric remnant polarization of 2Pr = 37.4 μC/cm2 and a low coercive electric field of 2Ec = 187 kV/cm at an applied electric field of 475 kV/cm. Furthermore, the lowest value of the leakage current density of 6.12×107 A/cm2 at an applied electric field of 100 kV/cm was measured for the Gd-doped NaBTi thin film

    A Robust and Low-Complexity Timing Synchronization Algorithm for ADSRC System

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    In this paper, a robust, low-complexity timing synchronization algorithm suitable for 5.9 GHz Dedicated Short Range Communications (DSRC) system is proposed. The proposed method uses cross-correlation technique to detect the starting point of both a short training symbol and the guard interval of the first long training symbol. This allows the proposed algorithm to have low-complex architecture. Compared to the scheme proposed by Chang and Kelly, the proposed algorithm attains considerably higher timing synchronization performance and significantly reduced computational complexity. Simulation results show that the proposed algorithm is robust and efficient in high-mobility environments and low signal-to-noise ratio (SNR) conditions

    Cdk5 Phosphorylates Dopamine D2 Receptor and Attenuates Downstream Signaling

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    The dopamine D2 receptor (DRD2) is a key receptor that mediates dopamine-associated brain functions such as mood, reward, and emotion. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase whose function has been implicated in the brain reward circuit. In this study, we revealed that the serine 321 residue (S321) in the third intracellular loop of DRD2 (D2i3) is a novel regulatory site of Cdk5. Cdk5-dependent phosphorylation of S321 in the D2i3 was observed in in vitro and cell culture systems. We further observed that the phosphorylation of S321 impaired the agonist-stimulated surface expression of DRD2 and decreased G protein coupling to DRD2. Moreover, the downstream cAMP pathway was affected in the heterologous system and in primary neuronal cultures from p35 knockout embryos likely due to the reduced inhibitory activity of DRD2. These results indicate that Cdk5-mediated phosphorylation of S321 inhibits DRD2 function, providing a novel regulatory mechanism for dopamine signaling.X111111sciescopu

    Effects of Promoter on the Formation of Gas Hydrate from Blast furnace Gas

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    Grapefruit Seed Extract as a Natural Derived Antibacterial Substance against Multidrug-Resistant Bacteria

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    Multidrug-resistant (MDR) bacteria are increasing due to the abuse and misuse of antibiotics, and nosocomial infections by MDR bacteria are also increasing. The aim of this study was to identify new substances that can target MDR bacteria among 12 plant extracts that are known to have antibacterial effects. The experiments were performed by the disk diffusion test and microdilution minimum inhibitory concentration (MIC) test, as described by the Clinical and Laboratory Standards Institute (CLSI). By screening against methicillin-sensitive Staphylococcus aureus (MSSA), grapefruit seed extract (GSE) was selected from 12 plant extracts for subsequent experiments. GSE showed antibacterial effects against methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) in the disk diffusion test. Even at the lowest concentration, GSE showed antibacterial activity in the microdilution MIC test. As a result, we can conclude that GSE is a naturally derived antibacterial substance that exhibits a favorable antibacterial effect even at a very low concentration, so it is a good candidate for a natural substance that can be used to prevent or reduce nosocomial infections as coating for materials used in medical contexts or by mixing a small amount with other material

    Activating signal cointegrator 2 required for liver lipid metabolism mediated by liver X receptors in mice

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    Activating signal cointegrator 2 (ASC-2), a cancer-amplified transcriptional coactivator of nuclear receptors and many other transcription factors, contains two LXXLL-type nuclear receptor interaction domains. Interestingly, the second LXXLL motif is highly specific to the liver X receptors (LXRs). In cotransfection, DN2, an ASC-2 fragment encompassing this motif, exerts a potent dominant-negative effect on transactivation by LXRs, which is rescued by ectopic coexpression of the full-length ASC-2 but not by other LXXLL-type coactivators, such as SRC-1 and TRAP220. In contrast, DN2/m, in which the LXXLL motif is mutated to LXXAA to abolish the interactions with LXRs, is without any effect. Accordingly, expression of DN2, but not DN2/m, in transgenic mice results in phenotypes that are highly homologous to those previously observed with LXRalpha(-/-) mice, including a rapid accumulation of large amounts of cholesterol and down-regulation of the known lipid-metabolizing target genes of LXRalpha in the liver upon being fed a high-cholesterol diet. These results identify ASC-2 as a physiologically important transcriptional coactivator of LXRs and demonstrate its pivotal role in the liver lipid metabolism.open1136sciescopu
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