63 research outputs found
Holographic Renyi entropies from hyperbolic black holes with scalar hair
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 , 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
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
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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