83 research outputs found

    p21WAF1/CIP1 gene transcriptional activation exerts cell growth inhibition and enhances chemosensitivity to cisplatin in lung carcinoma cell

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    BACKGROUND: Non-small-cell lung carcinomas (NSCLCs) exhibit poor prognosis and are usually resistant to conventional chemotherapy. Absence of p21WAF1/CIP1, a cyclin-dependent kinase (cdk) inhibitor, has been linked to drug resistance in many in vitro cellular models. RNA activation (RNAa) is a transcriptional activation phenomena guided by double-strand RNA (dsRNA) targeting promoter region of target gene. METHODS: In this study, we explored the effect of up-regulation of p21 gene expression on drug-resistance in A549 non-small-cell lung carcinoma cells by transfecting the dsRNA targeting the promoter region of p21 into A549 cells. RESULTS: Enhanced p21 expression was observed in A549 cells after transfection of dsRNA, which was correlated with a significant growth inhibition and enhancement of chemosensitivity to cisplatin in A549 cells in vitro. Moreover, in vivo experiment showed that saRNA targeting the promoter region of p21 could significantly inhibit A549 xenograft tumor growth. CONCLUSIONS: These results indicate that p21 plays a role in lung cancer drug-resistance process. In addition, this study also provides evidence for the usage of saRNA as a therapeutic option for up-regulating lower-expression genes in lung cancer

    Manipulating Multiple Order Parameters via Oxygen Vacancies: The case of Eu0.5Ba0.5TiO3-{\delta}

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    Controlling functionalities, such as magnetism or ferroelectricity, by means of oxygen vacancies (VO) is a key issue for the future development of transition metal oxides. Progress in this field is currently addressed through VO variations and their impact on mainly one order parameter. Here we reveal a new mechanism for tuning both magnetism and ferroelectricity simultaneously by using VO. Combined experimental and density-functional theory studies of Eu0.5Ba0.5TiO3-{\delta}, we demonstrate that oxygen vacancies create Ti3+ 3d1 defect states, mediating the ferromagnetic coupling between the localized Eu 4f7 spins, and increase an off-center displacement of Ti ions, enhancing the ferroelectric Curie temperature. The dual function of Ti sites also promises a magnetoelectric coupling in the Eu0.5Ba0.5TiO3-{\delta}.Comment: Accepted by Physical Review B, 201

    Foxtail Mosaic Virus-induced Flowering Assays in Monocot Crops

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    Virus-induced flowering (VIF) exploits RNA or DNA viruses to express flowering time genes to induce flowering in plants. Such plant virus-based tools have recently attracted widespread attention for their fundamental and applied uses in flowering physiology and in accelerating breeding in dicotyledonous crops and woody fruit-trees. We now extend this technology to a monocot grass and a cereal crop. Using the Foxtail mosaic virus-based VIF system, dubbed FoMViF, we showed that expression of florigenic Flowering Locus T (FT) genes can promote early flowering and spikelet development in proso millet, a C4 grass species with potential for nutritional food and biofuel resources, and in non-vermalized C3 wheat, a major food crop worldwide. Floral and spikelet/grain induction in the two monocot plants was caused by the virally expressed untagged or FLAG-tagged FT orthologues, and the florigenic activity of rice Hd3a was more pronounced than its dicotyledonous counterparts in proso millet. The FoMViF system is easy to perform and its efficacy to induce flowering and early spikelet/grain production is high. In addition to proso millet and wheat, we envisage that FoMViF will be also applicable to many economically important monocotyledonous food and biofuel crops

    Concentration protile of etchant measured by microelectrode technique in the process of chemical micromachining

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    A carbon-disk microelectrode was used to investigate the surface concentration profile of etchant Br-2, which was electrogenerated on the Pt working electrode. The steady state reducing currents of Br-2 at different distances away from the Pt electode was measured. The concentration profile was estimated from the current-distance variation curves as a function of different sampling times. Experimentally determined concentration profiles are in good agreement with those estimated from the microetching results. The microelectrode technique has offered a good method to choose suitable etching solution for chemical micromachining

    In Situ Development and High Temperature Features of CoCrFeNi-M6Cp High Entropy-Alloy Based Hardmetal

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    In this work, an in-situ CoCrFeNi-M6Cp high entropy-alloy (HEA) based hardmetal with a composition of Co25Cr21Fe18Ni23Mo7Nb3WC2 was fabricated by the powder metallurgy (PM) method. Microstructures and mechanical properties of this HEA were characterized and analyzed. The results exhibit that this HEA possesses a two-phase microstructure consisting of the face-centered cubic (FCC) matrix phase and the carbide M6C phase. This HEA has an average grain size of 2.2 μm, and the mean size and volume fraction of carbide particles are 1.2 μm and 20%. The tensile tests show that the alloy has a yield strength of 573 MPa, ultimate tensile strength of 895 MPa and elongation of 5.5% at room temperature. The contributions from different strengthening mechanisms in this HEA were calculated. The grain boundary strengthening is the dominant strengthening mechanism, and the carbide particles are significant for the further enhancement of yield strength by the dislocation strengthening and Orowan strengthening. In addition, with increasing temperatures from 600 °C to 900 °C, the HEA shows a reduced yield strength (YS) from 473 MPa to 142 MPa, a decreased ultimate tensile strength (UTS) from 741 MPa to 165 MPa and an enhanced elongation from 10.5% to 31%
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