508 research outputs found
Quantum illumination receiver using double homodyne detection
A quantum receiver is an essential element of quantum illumination (QI) which
outperforms its classical counterpart, called classical-illumination (CI).
However, there are only few proposals for realizable quantum receiver, which
exploits nonlinear effects leading to increasing the complexity of receiver
setups. To compensate this, in this article, we design a quantum receiver with
linear optical elements for Gaussian QI. Rather than exploiting nonlinear
effect, our receiver consists of a 50:50 beam splitter and homodyne detection.
Using double homodyne detection after the 50:50 beam splitter, we analyze the
performance of the QI in different regimes of target reflectivity, source
power, and noise level. We show that our receiver has better signal-to-noise
ratio and more robust against noise than the existing simple-structured
receivers.Comment: 9 pages, 6 figure
Trapping a Free-propagating Single-photon into an Atomic Ensemble as a Quantum Stationary Light Pulse
Efficient photon-photon interaction is one of the key elements for realizing
quantum information processing. The interaction, however, must often be
mediated through an atomic medium due to the bosonic nature of photons, and the
interaction time, which is critically linked to the efficiency, depends on the
properties of the atom-photon interaction. While the electromagnetically
induced transparency effect does offer the possibility of photonic quantum
memory, it does not enhance the interaction time as it fully maps the photonic
state to an atomic state. The stationary light pulse (SLP) effect, on the
contrary, traps the photonic state inside an atomic medium with zero group
velocity, opening up the possibility of the enhanced interaction time. In this
work, we report the first experimental demonstration of trapping a
free-propagating single-photon into a cold atomic ensemble via the quantum SLP
(QSLP) process. We conclusively show that the quantum properties of the
single-photon state are preserved well during the QSLP process. Our work paves
the way to new approaches for efficient photon-photon interactions, exotic
photonic states, and many-body simulations in photonic systems
Suppressive Effect on Lipopolysaccharide-Induced Proinflammatory Mediators by Citrus aurantium L. in Macrophage RAW 264.7 Cells via NF-κB Signal Pathway
Citrus fruits have been used as an edible fruit and a traditional medicine since ancient times. In particular, the peels of immature citrus fruits are used widely in traditional herbal medicine in Korea, as they are believed to contain bioactive components exerting anti-inflammatory activity. This study examined whether the crude methanol extract of Citrus aurantium L. (CME) has a suppressive effect on inducible enzymes and proinflammatory cytokines by inhibiting the NF-κB pathway in LPS-stimulated macrophage RAW 264.7 cells. The cells were pretreated with the indicated concentrations of CME (5, 10, 20, and 50 μg/mL) and then treated with LPS (1 μg/mL). The results showed that CME (10, 20, and 50 μg/mL) inhibited the LPS- (1 μg/mL) induced mRNA and protein expression of iNOS in macrophage Raw 264.7 cells. In addition, the expression of COX-2 was inhibited at the mRNA and protein levels by CME in a dose-dependent manner. The mRNA expression of proinflammatory cytokines, such as TNF-α and IL-6, were markedly reduced by CME (10, 20, and 50 μg/mL). Moreover, CME clearly suppressed the nuclear translocation of the NF-κB p65 subunits, which was correlated with its inhibitory effect on I-κB phosphorylation. These results suggest that CME has anti-inflammatory properties by modulating the expression of COX-2, iNOS, and proinflammatory cytokines, such as TNF-α and IL-6, in macrophage RAW 264.7 cells via the NF-κB pathway
Electrical Characterization of Proposed Transpositional Acupoints on the Urinary Bladder Meridian in a Rat Model
Specific electrical characteristicsof acupointswere investigated on the urinary bladder (BL) meridian in 14 rats. BL acupointsand non-acupoints on the back were selected and their electrical voltages were measured by using aSPACsystem.The mean voltages of each point or each line were statistically analyzed by using the ANOVA test.The BL meridian showed voltages higher than those of the reference line (P < .05). Bilateral 1st BL lines presented higher voltages than bilateral 2nd BL lines (P < .05). Most BL acupoints had voltageshigher than those for the corresponding reference points (P < .05). In particular, theright BL16 exhibited the biggest difference from the reference point, followed by the left extra BL point-2, the right BL27, the left BL17, and theleft BL45. Additionally, the distributions of neurofilamentsfor several points were investigated by using immunohistochemistry. There was a trend for the BL acupoints to have larger numbers of neurofilaments than the reference points, and that trend seemed to be directly proportional to the difference in voltage between the points.In conclusion, BL acupoints on the back in ratsexhibited specific electric and histologic characteristics. Therefore, those acupointsmay be utilized to investigate the efficacy of acupuncturewith laboratory animals
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