2,058 research outputs found
Anti‐atherosclerotic effect of the angiotensin 1–7 mimetic AVE0991 is mediated by inhibition of perivascular and plaque inflammation in early atherosclerosis
Background and Purpose:
Inflammation plays a key role in atherosclerosis. A protective role of angiotensin-(1-7) in vascular pathologies opened a possibility for therapeutic use of small molecule non-peptide Ang-(1-7) mimetics, such as AVE0991. The mechanisms of these vaso-protective effects of a Mas receptor agonist, AVE0991, remain unclear.
Experimental approach:
We investigated the effects of AVE0991 on the spontaneous atherosclerosis in ApoE-/- mice, in the context of vascular inflammation and plaque stability.
Key Results:
AVE0991 has significant anti-atherosclerotic properties in ApoE-/- mice and increases plaque stability, by reducing plaque macrophage content, without effects on collagen. Using descending aorta of chow fed ApoE-/- mice, before significant atherosclerotic plaque develops, we gained insight to early events in atherosclerosis. Interestingly, perivascular adipose tissue (pVAT) and adventitial infiltration with macrophages and T cells precedes atherosclerotic plaque or the impairment of endothelium-dependent NO bioavailability as a measure of endothelial function. AVE0991 inhibited perivascular inflammation, through the reduction of chemokine expression in pVAT, as well as through direct actions on monocytes/macrophages inhibiting their activation, characterized by IL-1β, TNF-α, MCP-1 and CXCL10 and differentiation to M1 phenotype. Pre-treatment with AVE0991 inhibited migration of THP-1 monocytes towards supernatants of activated adipocytes (SW872). Mas receptors were expressed in pVAT and in THP-1 cells in vitro and anti-inflammatory effects of AVE0991 were partially Mas dependent.
Conclusions & implications:
Selective Mas receptor agonist AVE0991 possesses anti-atherosclerotic and anti-inflammatory properties, affecting monocyte/macrophage differentiation and recruitment to perivascular space at early stages of atherosclerosis in ApoE-/- mice
Fast optical preparation, control, and readout of a single quantum dot spin
We propose and demonstrate the sequential initialization, optical control, and readout of a single spin trapped in a semiconductor quantum dot. Hole spin preparation is achieved through ionization of a resonantly excited electron-hole pair. Optical control is observed as a coherent Rabi rotation between the hole and charged-exciton states, which is conditional on the initial hole spin state. The spin-selective creation of the charged exciton provides a photocurrent readout of the hole spin state. © 2008 The American Physical Society
Concentrations of , radionuclides and some heavy metals in soil samples of Chochołowska Valley from Tatra National Park
This paper presents the results of determination of artificial and natural activity concentrations
and some heavy metals in soil samples from the region of one of the main valleys of Tatra National Park
(Chochołowska). Our investigation concentrated on and heavy metal levels in mountain soil taken
from Chochołowska Valley, which revealed great variability in their concentration. The results show considerably
small amounts of radionuclides and in the soils. Larger amounts of those elements can
be found in the organic surface horizons of the soils. The evaluation of the content of those elements must
be based on the bulk density analysis of the soil
Quantum teleportation of laser-generated photons with an entangled-light-emitting diode
Quantum teleportation can transfer information between physical systems, which is essential for engineering quantum networks. Of the many technologies being investigated to host quantum bits, photons have obvious advantages as ‘pure’ quantum information carriers, but their bandwidth and energy is determined by the quantum system that generates them. Here we show that photons from fundamentally different sources can be used in the optical quantum teleportation protocol. The sources we describe have bandwidth differing by a factor over 100, but we still observe teleportation with average fidelity of 0.77, beating the quantum limit by 10 standard deviations. Furthermore, the dissimilar nature of our sources exposes physics hidden in previous experiments, which we also predict numerically. These phenomena include converting qubits from Poissonian to Fock statistics, quantum interference, beats and teleportation for spectrally non-degenerate photons, and acquisition of evolving character following teleportation of a qubit
Spin-photon entanglement with direct photon emission in the telecom C-band
The ever-evolving demands for computational power and for a securely
connected world dictate the development of quantum networks where entanglement
is distributed between connected parties. Solid-state quantum emitters in the
telecom C-band are a promising platform for quantum communication applications
due to the minimal absorption of photons at these wavelengths, "on-demand"
generation of single photon flying qubits, and ease of integration with
existing network infrastructure. Here, we use an InAs/InP quantum dot to
implement an optically active spin-qubit, based on a negatively charged exciton
where the electron spin degeneracy is lifted using a Voigt magnetic field. We
investigate the coherent interactions of the spin-qubit system under resonant
excitation, demonstrating high fidelity spin initialisation and coherent
control using picosecond pulses. We further use these tools to measure the
coherence of a single, undisturbed electron spin in our system. Finally, we
report the first demonstration of spin-photon entanglement in a solid-state
system capable of direct emission into the telecom C-band.Comment: 19 pages (including references), 5 figure
Giant Gravitons, BPS bounds and Noncommutativity
It has been recently suggested that gravitons moving in
spacetimes along the blow up into spherical branes whose radius
increases with increasing angular momentum. This leads to an upper bound on the
angular momentum, thus ``explaining'' the stringy exclusion principle. We show
that this bound is present only for states which saturate a BPS-like condition
involving the energy and angular momentum , , where is
the radius of . Restriction of motion to such states lead to a
noncommutativity of the coordinates on . As an example of motions which do
not obey the exclusion principle bound, we show that there are finite action
instanton configurations interpolating between two possible BPS states. We
suggest that this is consistent with the proposal that there is an effective
description in terms of supergravity defined on noncommutative spaces and
noncommutativity arises here because of imposing supersymmetry.Comment: 15 pages, harvmac, corrected some typo
Predictions for PP-wave string amplitudes from perturbative SYM
The role of general two-impurity multi-trace operators in the BMN
correspondence is explored. Surprisingly, the anomalous dimensions of all
two-impurity multi-trace BMN operators to order g_2^2\lambda' are completely
determined in terms of single-trace anomalous dimensions. This is due to
suppression of connected field theory diagrams in the BMN limit and this fact
has important implications for some string theory processes on the PP-wave
background. We also make gauge theory predictions for the matrix elements of
the light-cone string field theory Hamiltonian in the two string-two string and
one string-three string sectors.Comment: 46 pages, 12 figures. V3:typos correcte
Minimal Gaugino Mediation
We propose Minimal Gaugino Mediation as the simplest known solution to the
supersymmetric flavor and CP problems. The framework predicts a very minimal
structure for the soft parameters at ultra-high energies: gaugino masses are
unified and non-vanishing whereas all other soft supersymmetry breaking
parameters vanish. We show that this boundary condition naturally arises from a
small extra dimension and present a complete model which includes a new
extra-dimensional solution to the mu problem. We briefly discuss the predicted
superpartner spectrum as a function of the two parameters of the model. The
commonly ignored renormalization group evolution above the GUT scale is crucial
to the viability of Minimal Gaugino Mediation but does not introduce new model
dependence.Comment: LaTeX, 16 pages, 4 figures, running of the bottom and tau Yukawas
included, plots revise
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