2,047 research outputs found
Van der Waals-like phase transition from holographic entanglement entropy in Lorentz breaking massive gravity
In this paper, phase transition of AdS black holes in lorentz breaking
massive gravity has been studied in the framework of holography. We find that
there is a first order phase transition(FPT) and second order phase
transition(SPT) both in Bekenstein-Hawking entropy(BHE)-temperature plane and
holographic entanglement entropy(HEE)-temperature plane. Furthermore, for the
FPT, the equal area law is checked and for the SPT, the critical exponent of
the heat capacity is also computed. Our results confirm that the phase
structure of HEE is similar to that of BHE in lorentz breaking massive gravity,
which implies that HEE and BHE have some potential underlying relationship.Comment: 10 pages, 10 figure
Mutual correlation in the shock wave geometry
We probe the shock wave geometry with the mutual correlation in a spherically
symmetric Reissner Nordstr\"om AdS black hole on the basis of the gauge/gravity
duality. In the static background, we find that the regions living on the
boundary of the AdS black holes are correlated provided the considered regions
on the boundary are large enough. We also investigate the effect of the charge
on the mutual correlation and find that the bigger the value of the charge is,
the smaller the value of the mutual correlation will to be. As a small
perturbation is added at the AdS boundary, the horizon shifts and a dynamical
shock wave geometry forms after long time enough. In this dynamic background,
we find that the greater the shift of the horizon is, the smaller the mutual
correlation will to be. Especially for the case that the shift is large enough,
the mutual correlation vanishes, which implies that the considered regions on
the boundary are uncorrelated. The effect of the charge on the mutual
correlation in this dynamic background is found to be the same as that in the
static background.Comment: 10 page
Thermodynamics and weak cosmic censorship conjecture of the torus-like black hole
After studying the energy-momentum relation of charged particles'
Hamilton-Jacobi equations, we discuss the laws of thermodynamics and the weak
cosmic censorship conjecture in torus-like black holes. We find that both the
first law of thermodynamic as well as the weak cosmic censorship conjecture are
valid in both the normal phase space and extended phase space. However, the
second law of thermodynamics is only valid in the normal phase space. Our
results show that the first law and weak cosmic censorship conjecture do not
depend on the phase spaces while the second law depends. What's more, we find
that the shift of the metric function that determines the event horizon take
the same form in different phase spaces, indicating that the weak cosmic
censorship conjecture is independent of the phase space.Comment: 15 page
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Linezolid and Rifampicin Combination to Combat cfr-Positive Multidrug-Resistant MRSA in Murine Models of Bacteremia and Skin and Skin Structure Infection.
Linezolid resistance mediated by the cfr gene in MRSA represents a global concern. We investigated relevant phenotype differences between cfr-positive and -negative MRSA that contribute to pathogenesis, and the efficacy of linezolid-based combination therapies in murine models of bacteremia and skin and skin structure infection (SSSI). As a group, cfr-positive MRSA exhibited significantly reduced susceptibilities to the host defense peptides tPMPs, human neutrophil peptide-1 (hNP-1), and cathelicidin LL-37 (P < 0.01). In addition, increased binding to fibronectin (FN) and endothelial cells paralleled robust biofilm formation in cfr-positive vs. -negative MRSA. In vitro phenotypes of cfr-positive MRSA translated into poor outcomes of linezolid monotherapy in vivo in murine bacteremia and SSSI models. Importantly, rifampicin showed synergistic activity as a combinatorial partner with linezolid, and the EC50 of linezolid decreased 6-fold in the presence of rifampicin. Furthermore, this combination therapy displayed efficacy against cfr-positive MRSA at clinically relevant doses. Altogether, these data suggest that the use of linezolid in combination with rifampicin poses a viable therapeutic alternative for bacteremia and SSSI caused by cfr-positive multidrug resistant MRSA
How tyramine β-hydroxylase controls the production of octopamine, modulating the mobility of beetles
Biogenic amines perform many kinds of important physiological functions in the central nervous system (CNS) of insects, acting as neuromodulators, neurotransmitters, and neurohormones. The five most abundant types of biogenic amines in invertebrates are dopamine, histamine, serotonin, tyramine, and octopamine (OA). However, in beetles, an important group of model and pest insects, the role of tyramine beta-hydroxylase (T beta H) in the OA biosynthesis pathway and the regulation of behavior remains unknown so far. We therefore investigated the molecular characterization and spatiotemporal expression profiles of T beta H in red flour beetles (Triboliun castaneum). Most importantly, we detected the production of OA and measured the crawling speed of beetles after dsTcT beta H injection. We concluded that TcT beta H controls the biosynthesis amount of OA in the CNS, and this in turn modulates the mobility of the beetles. Our new results provided basic information about the key genes in the OA biosynthesis pathway of the beetles, and expanded our knowledge on the physiological functions of OA in insects
Pseudogap, Superconducting Energy Scale, and Fermi Arcs in Underdoped Cuprate Superconductors
Through the measurements of magnetic field dependence of specific heat in
in zero temperature limit, we determined the nodal slope
of the quasiparticle gap. It is found that has a very
similar doping dependence of the pseudogap temperature or value
. Meanwhile the virtual maximum gap at () derived from
is found to follow the simple relation upon
changing the doping concentration. This strongly suggests a close relationship
between the pseudogap and superconductivity. It is further found that the
superconducting transition temperature is determined by both the residual
density of states of the pseudogap phase and the nodal gap slope in the zero
temperature limit, namely, , where
is the extracted zero temperature value of the normal state
specific heat coefficient which is proportional to the size of the residual
Fermi arc . This manifests that the superconductivity may be formed by
forming a new gap on the Fermi arcs near nodes below . These observations
mimic the key predictions of the SU(2) slave boson theory based on the general
resonating-valence-bond (RVB) picture.Comment: 6 pages, 6 figures, to be published in Phys. Rev.
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