3,887 research outputs found
Constitutive upregulation of transcription factors underlies permissive bradyzoite differentiation in a natural isolate of Toxoplasma gondii
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Beating the Clauser-Horne-Shimony-Holt and the Svetlichny games with Optimal States
We study the relation between the maximal violation of Svetlichny's
inequality and the mixedness of quantum states and obtain the optimal state
(i.e., maximally nonlocal mixed states, or MNMS, for each value of linear
entropy) to beat the Clauser-Horne-Shimony-Holt and the Svetlichny games. For
the two-qubit and three-qubit MNMS, we showed that these states are also the
most tolerant state against white noise, and thus serve as valuable quantum
resources for such games. In particular, the quantum prediction of the MNMS
decreases as the linear entropy increases, and then ceases to be nonlocal when
the linear entropy reaches the critical points and for the
two- and three-qubit cases, respectively. The MNMS are related to classical
errors in experimental preparation of maximally entangled states.Comment: 7 pages, 3 figures; minor changes; accepted in Physical Review
Synergistic effect of phosphodiesterase 4 inhibitor and serum on migration of endotoxin-stimulated macrophages.
Macrophage migration is an essential step in host defense against infection and wound healing. Elevation of cAMP by inhibiting phosphodiesterase 4 (PDE4), enzymes that specifically degrade cAMP, is known to suppress various inflammatory responses in activated macrophages, but the role of PDE4 in macrophage migration is poorly understood. Here we show that the migration of Raw 264.7 macrophages stimulated with LPS was markedly and dose-dependently induced by the PDE4 inhibitor rolipram as assessed by scratch wound healing assay. Additionally, this response required the involvement of serum in the culture medium as serum starvation abrogated the effect. Further analysis revealed that rolipram and serum exhibited synergistic effect on the migration, and the influence of serum was independent of PDE4 mRNA expression in LPS-stimulated macrophages. Moreover, the enhanced migration by rolipram was mediated by activating cAMP/exchange proteins directly activated by cAMP (Epac) signaling, presumably via interaction with LPS/TLR4 signaling with the participation of unknown serum components. These results suggest that PDE4 inhibitors, together with serum components, may serve as positive regulators of macrophage recruitment for more efficient pathogen clearance and wound repair
Geometric phase for nonlinear coherent and squeezed state
The geometric phases for standard coherent states which are widely used in
quantum optics have attracted a large amount of attention. Nevertheless, few
physicists consider about the counterparts of non-linear coherent states, which
are useful in the description of the motion of a trapped ion. In this paper,
the non-unitary and non-cyclic geometric phases for two nonlinear coherent and
one squeezed states are formulated respectively. Moreover, some of their common
properties are discussed respectively, such as gauge invariance, non-locality
and non-linear effects. The non-linear functions have dramatic impacts on the
evolution of the corresponding geometric phases. They speed the evolution up or
down. So this property may have application in controlling or measuring
geometric phase. For the squeezed case, when the squeezed parameter r ->
\infinity, the limiting value of the geometric phase is also determined by
non-linear function at a given time and angular velocity. In addition, the
geometric phases for standard coherent and squeezed states are obtained under a
particular condition. When the time evolution undergoes a period, their
corresponding cyclic geometric phases are achieved as well. And the distinction
between the geometric phases of the two coherent states maybe regarded as a
geometric criterion
Improved visible-light activities of nanocrystalline CdS by coupling with ultrafine NbN with lattice matching for hydrogen evolution
Metallic ultrafine NbN with lattice matching to nanocrystalline CdS could replace the expensive platinum for efficiently trapping photogenerated electrons, enhancing charge separation and then activating the preferentially adsorbed H_{2}O to produce H_{2}, mainly confirmed by Kelvin probe experiments, Mott–Schottky plots, amount of ˙OH produced, electrochemical experiments and density-functional-theory calculations
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