4,389 research outputs found
Classical Aspects of Higher Spin Topologically Massive Gravity
We study the classical solutions of three dimensional topologically massive
gravity (TMG) and its higher spin generalization, in the first order
formulation. The action of higher spin TMG has been proposed in arXiv:1110.5113
to be of a Chern-Simons-like form. The equations of motion are more complicated
than the ones in pure higher spin AdS gravity, but are still tractable. As
all the solutions in higher spin gravity are automatically the solutions of
higher spin TMG, we focus on other solutions. We manage to find the AdS pp-wave
solutions with higher spin hair, and find that the nonvanishing higher spin
fields may or may not modify the pp-wave geometry. In order to discuss the
warped spacetime, we introduce the notion of special Killing vector, which is
defined to be the symmetry on the frame-like fields. We reproduce various
warped spacetimes of TMG in our framework, with the help of special Killing
vectors.Comment: 25 pages; minor corrections, references added, published versio
Automatic recognition of radar signals based on time-frequency image shape character
Radar signal recognition is one of the key technologies of modern electronic surveillance systems. Time-frequency image provides a new way for recognizing the radar signal. In this paper, a series of image processing methods containing image enhancement, image threshold binarization and mathematical morphology is utilized to extract the shape character of smoothed pseudo wigner-ville time-frequency distribution of radar signal. And then the identification of radar signal is realized by the character. Simulation results of eight kinds of typical radar signal demonstrate that when signal noise ratio (SNR) is greater than -3 dB, the Legendre moments shape character of the time-frequency image is very stable. Moreover, the recognition rate by the character is more than 90 per cent except for the FRANK code signal when SNR > -3 dB. Test also show that the proposed method can effectively recognize radar signal with less character dimension through compared with exitsing algorithms.Defence Science Journal, 2013, 63(3), pp.308-314, DOI:http://dx.doi.org/10.14429/dsj.63.240
Tetrakis(μ-phenoxyacetato-κ2 O:O′)bis[(1,10-phenanthroline-κ2 N,N′)manganese(II)] methanol hemisolvate
The title complex, [Mn2(C8H7O3)4(C12H8N2)2]·0.5CH3OH, is a carboxylate-bridged dinuclear MnII complex with four phenoxyacetate ions and two 1,10-phenanthroline molecules as ligands. Each of the four phenoxyacetate anions bridges the pair of Mn atoms. The asymmetric unit is completed by a half-occupancy methanol solvent molecule. Face-to-face π–π stacking interactions between the aromatic rings of 1,10-phenanthroline molecules belonging to adjacent Mn2 complexes, with an interplanar separation of circa 3.4 Å, and weak C—H⋯O hydrogen bonds connect the dinuclear units into a three-dimensional supramolecular framework
Antioxidant and Anti-Inflammatory Activities of Berberine in the Treatment of Diabetes Mellitus
Hepatitis C: From inflammatory pathogenesis to anti-inflammatory/hepatoprotective therapy
Hepatitis C virus (HCV) infection commonly causes progressive liver diseases that deteriorate from chronic inflammation to fibrosis, cirrhosis and even to hepatocellular carcinoma. A long-term, persistent and uncontrolled inflammatory response is a hallmark of these diseases and further leads to hepatic injury and more severe disease progression. The levels of inflammatory cytokines and chemokines change with the states of infection and treatment, and therefore, they may serve as candidate biomarkers for disease progression and therapeutic effects. The mechanisms of HCV-induced inflammation involve classic pathogen pattern recognition, inflammasome activation, intrahepatic inflammatory cascade response, and oxidative and endoplasmic reticulum stress. Direct-acting antivirals (DAAs) are the first-choice therapy for effectively eliminating HCV, but DAAs alone are not sufficient to block the uncontrolled inflammation and severe liver injury in HCV-infected individuals. Some patients who achieve a sustained virologic response after DAA therapy are still at a long-term risk for progression to liver cirrhosis and hepatocellular carcinoma. Therefore, coupling with anti-inflammatory/hepatoprotective agents with anti-HCV effects is a promising therapeutic regimen for these patients during or after treatment with DAAs. In this review, we discuss the relationship between inflammatory mediators and HCV infection, summarize the mechanisms of HCV-induced inflammation, and describe the potential roles of anti-inflammatory/hepatoprotective drugs with anti-HCV activity in the treatment of advanced HCV infection
(Z)-2-Hydroxy-3-(4-methoxyphenyl)acrylic acid
In the structure of the title compound, C10H10O4, inversion dimers linked by pairs of O—H⋯O hydrogen bonds link the carboxylic acid groups. Further O—H⋯O links cross-link the dimers into sheets running along the b-axis direction
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