63 research outputs found

    Holographic Renyi entropies from hyperbolic black holes with scalar hair

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    The Renyi entropies as a generalization of the entanglement entropy imply much more information. We analytically calculate the Renyi entropies (with a spherical entangling surface) by means of a class of neutral hyperbolic black holes with scalar hair as a one-parameter generalization of the MTZ black hole. The zeroth-order and third-order phase transitions of black holes lead to discontinuity of the first and second derivatives of the Renyi entropies, respectively. From the Renyi entropies which are analytic at n=∞n=\infty, we can express the entanglement spectrum as an infinite sum in terms of the Bell polynomial. We show that the analytic treatment is in agreement with numerical calculations for the low-lying entanglement spectrum in a wide range of parameters.Comment: 28 pages, 5 figure

    Development of novel 9-O-substituted-13-octylberberine derivatives as potential anti-hepatocellular carcinoma agents

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    A series of novel 9-O-substituted-13-octylberberine derivatives were designed, synthesised and evaluated for their anti-hepatocellular carcinoma (HCC) activities. Compound 6k showed the strongest activity against three human hepatoma cells including HepG2, Sk-Hep-1 and Huh-7 cells with IC50 values from 0.62 to 1.69 μM, which were much superior to berberine (IC50 >50 μM). More importantly, 6k exhibited lower cytotoxicity against normal hepatocytes L-02 with good lipid-water partition properties. The mechanism studies revealed that 6k caused G2/M phase arrest of the cell cycle, stabilised G-quadruplex DNA, and induced apoptosis via a mitochondrial apoptotic pathway. Finally, the invivo anti-HCC activity of 6k was validated in the H22 liver cancer xenograft mouse model. Collectively, the current study would provide a new insight into the discovery of novel, safe and effective anti-HCC agents

    Anapole mediated giant photothermal nonlinearity in nanostructured silicon

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    Featured with a plethora of electric and magnetic Mie resonances, high index dielectric nanostructures offer a versatile platform to concentrate light-matter interactions at the nanoscale. By integrating unique features of far-field scattering control and near-field concentration from radiationless anapole states, here, we demonstrate a giant photothermal nonlinearity in single subwavelength-sized silicon nanodisks. The nanoscale energy concentration and consequent near-field enhancements mediated by the anapole mode yield a reversible nonlinear scattering with a large modulation depth and a broad dynamic range, unveiling a record-high nonlinear index change up to 0.5 at mild incident light intensities on the order of MW/cm2. The observed photothermal nonlinearity showcases three orders of magnitude enhancement compared with that of unstructured bulk silicon, as well as nearly one order of magnitude higher than that through the radiative electric dipolar mode. Such nonlinear scattering can empower distinctive point spread functions in confocal reflectance imaging, offering the potential for far-field localization of nanostructured Si with an accuracy approaching 40 nm. Our findings shed new light on active silicon photonics based on optical anapoles
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