3,757 research outputs found
Distinct Role of IL-27 in Immature and LPS-Induced Mature Dendritic Cell-Mediated Development of CD4
Interleukin-27 (IL-27) plays an important role in regulation of anti-inflammatory responses and autoimmunity; however, the molecular mechanisms of IL-27 in modulation of immune tolerance and autoimmunity have not been fully elucidated. Dendritic cells (DCs) play a central role in regulating immune responses mediated by innate and adaptive immune systems, but regulatory mechanisms of DCs in CD4+ T cell-mediated immune responses have not yet been elucidated. Here we show that IL-27 treated mature DCs induced by LPS inhibit immune tolerance mediated by LPS-stimulated DCs. IL-27 treatment facilitates development of the CD4+ CD127+3G11+ regulatory T cell subset in vitro and in vivo. By contrast, IL-27 treated immature DCs fail to modulate development of the CD4+CD127+3G11+ regulatory T cell sub-population in vitro and in vivo. Our results suggest that IL-27 may break immune tolerance induced by LPS-stimulated mature DCs through modulating development of a specific CD4+ regulatory T cell subset mediated by 3G11 and CD127. Our data reveal a new cellular regulatory mechanism of IL-27 that targets DC-mediated immune responses in autoimmune diseases such as multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). © 2018 Zhou, Zhang and Rostami
Effects of Collisional Decoherence on Multipartite Entanglement - How would entanglement not be relatively common?
We consider the collision model of Ziman {\em et al.} and study the
robustness of -qubit Greenberger-Horne-Zeilinger (GHZ), W, and linear
cluster states. Our results show that -qubit entanglement of GHZ states
would be extremely fragile under collisional decoherence, and that of W states
could be more robust than of linear cluster states. We indicate that the
collision model of Ziman {\em et al.} could provide a physical mechanism to
some known results in this area of investigations. More importantly, we show
that it could give a clue as to how -partite distillable entanglement would
be relatively rare in our macroscopic classical world.Comment: 10 page
Teleporting a rotation on remote photons
Quamtum remote rotation allows implement local quantum operation on remote
systems with shared entanglement. Here we report an experimental demonstration
of remote rotation on single photons using linear optical element. And the
local dephase is also teleported during the process. The scheme can be
generalized to any controlled rotation commutes with .Comment: 5 pages, 4 figure
Methods for linear optical quantum Fredkin gate
We consider the realization of quantum Fredkin gate with only linear optics
and single photons. First we construct a heralded Fredkin gate using four
heralded controlled-not (CNOT) gates. Then we simplify this method to a
post-selected one utilizing only two CNOT gates. We also give a possible
realization of this method which is feasible with current experimental
technology. Another post-selected scheme requires time entanglement of the
input photons but needs no ancillary photons.Comment: 5 pages, 5 figure
Entanglement measurement based on two-particle interference
We propose a simple and realizable method using a two-particle interferometer
for the experimental measurement of pairwise entanglement, assuming some prior
knowledge about the quantum state. The basic idea is that the properties of the
density matrix can be revealed by the single- and two-particle interference
patterns. The scheme can easily be implemented with polarized entangled
photons.Comment: 5 pages, 1 figur
Generation of a High-Visibility Four-Photon Entangled State and Realization of a Four-Party Quantum Communication Complexity Scenario
We obtain a four-photon polarization-entangled state with a visibility as
high as (95.35\pm 0.45)% directly from a single down-conversion source. A
success probability of (81.54\pm 1.38)% is observed by applying this entangled
state to realize a four-party quantum communication complexity scenario (QCCS),
which comfortably surpass the classical limit of 50%. As a comparison, two
Einstein-Podolsky-Rosen (EPR) pairs are shown to implement the scenario with a
success probability of (73.89\pm 1.33)%. This four-photon state can be used to
fulfill decoherence-free quantum information processing and other advanced
quantum communication schemes.Comment: REVTEX 4.0, 4 pages, 4 figures, 1 tabl
Remote Preparation of Mixed States via Noisy Entanglement
We present a practical and general scheme of remote preparation for pure and
mixed state, in which an auxiliary qubit and controlled-NOT gate are used. We
discuss the remote state preparation (RSP) in two important types of decoherent
channel (depolarizing and dephaseing). In our experiment, we realize RSP in the
dephaseing channel by using spontaneous parametric down conversion (SPDC),
linear optical elements and single photon detector.Comment: 10 pages, 5 figures, submitted to PR
Local Operations in qubit arrays via global but periodic Manipulation
We provide a scheme for quantum computation in lattice systems via global but
periodic manipulation, in which only effective periodic magnetic fields and
global nearest neighbor interaction are required. All operations in our scheme
are attainable in optical lattice or solid state systems. We also investigate
universal quantum operations and quantum simulation in 2 dimensional lattice.
We find global manipulations are superior in simulating some nontrivial many
body Hamiltonians.Comment: 5 pages, 2 figures, to appear in Phys. Rev.
Stability of Pairwise Entanglement in a Decoherent Environment
Consider the dynamics of a two-qubit entangled system in the decoherence
environment, we investigate the stability of pairwise entanglement under
decoherence. We find that for different decoherence models, there exist some
special class of entangled states of which the pairwise entanglement is the
most stable. The lifetime of the entanglement in these states is larger than
other states with the same initial entanglement. In addition, we also
investigate the dynamics of pairwise entanglement in the ground state of spin
models such as Heisenberg and XXY models.Comment: accepted by Physical Review A, references updated and minor change
Explanation of the colossal detonation sensitivity of silicon pentaerythritol tetranitrate (Si-PETN) explosive
DFT calculations have identified the novel rearrangement shown here for decomposition of the Si derivative of the PETN explosive [pentaerythritol tetranitrate (PETN), C(CH_2ONO_2)_4] that explains the very dramatic increase in sensitivity observed experimentally. The critical difference is that Si-PETN allows a favorable five-coordinate transition state in which the new Si−O and C−O bonds form simultaneously, leading to a transition state barrier of 33 kcal/mol (it is 80 kcal/mol for PETN) and much lower than the normal O−NO_2 bond fission observed in other energetic materials (40 kcal/mol). In addition this new mechanism is very exothermic (45 kcal/mol) leading to a large net energy release at the very early stages of Si-PETN decomposition that facilitates a rapid temperature increase and expansion of the reaction zone
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