158 research outputs found
Enhanced temperature sensing by multi-mode coupling in an on-chip microcavity system
The micro-cavity is a promising sensor platform, any perturbation would
disturb its linewidth, cause resonance shift or splitting. However, such
sensing resolution is limited by the cavity's optical quality factor and mode
volume. Here we propose and demonstrate in an on-chip integrated microcavity
system that resolution of a self referenced sensor could be enhanced with multi
mode coupling
Deterministic realization of collective measurements via photonic quantum walks
Collective measurements on identically prepared quantum systems can extract
more information than local measurements, thereby enhancing
information-processing efficiency. Although this nonclassical phenomenon has
been known for two decades, it has remained a challenging task to demonstrate
the advantage of collective measurements in experiments. Here we introduce a
general recipe for performing deterministic collective measurements on two
identically prepared qubits based on quantum walks. Using photonic quantum
walks, we realize experimentally an optimized collective measurement with
fidelity 0.9946 without post selection. As an application, we achieve the
highest tomographic efficiency in qubit state tomography to date. Our work
offers an effective recipe for beating the precision limit of local
measurements in quantum state tomography and metrology. In addition, our study
opens an avenue for harvesting the power of collective measurements in quantum
information processing and for exploring the intriguing physics behind this
power.Comment: Close to the published versio
A density functional study of the effect of hydrogen on electronic properties and band discontinuity at anatase TiO2/diamond interface
Tailoring the electronic states of the dielectric oxide/diamond interface is critical to the development of next generation semiconductor devices like high-power high-frequency field-effect transistors. In this work, we investigate the electronic states of the TiO2/diamond 2 × 1-(100) interface by using first principles total energy calculations. Based on the calculation of the chemical potentials for the TiO2/diamond interface, it is observed that the hetero-interfaces with the C-OTi configuration or with two O vacancies are the most energetically favorable structures under the O-rich condition and under Ti-rich condition, respectively. The band structure and density of states of both TiO2/diamond and TiO2/H-diamond hetero-structures are calculated. It is revealed that there are considerable interface states at the interface of the anatase TiO2/diamond hetero-structure. By introducing H on the diamond surface, the interface states are significantly suppressed. A type-II alignment band structure is disclosed at the interface of the TiO2/diamond hetero-structure. The valence band offset increases from 0.6 to 1.7 eV when H is introduced at the TiO2/diamond interface
Mechanistic study of endothelium independent vasodilation effects of wogonin
34-40Scutellaria baicalensis Georgi, locally known as HuangQin, and commonly as Baikal or Chinese skullcap, is an
important herb in Chinese traditional medicine. The flavonoids from this plant are main active substances responsible for its
medicinal applications. Wogonin is one such active ingredient derived from this plant. Here, we investigated the mechanism
of the vasodilation effect of wogonin on isolated rat thoracic aortas. For this study, endothelium intact and endothelium
removed thoracic aortic rings were prepared from rats. Using a tension transducer, the tension of the rat thoracic aortic rings
was recorded. Results showed that wogonin is able to relax the endothelium-intact aortic rings, but L-NAME, indomethacin
(Indo), and methylene blue (MB) could not reduce the tension in these rings. Wogonin was also able to relax endotheliumremoved
rings. However, treatment with tetraethylammonium (TEA), BaCl2, glibenclamide (Gly), 4-aminopyridine (4-AP),
and verapamil (Ver) had no effect on vasodilation induced by wogonin. Using wogonin to pre-treat endothelium-removed
aortic rings reduced the contraction induced by K+. Pre-treatment of endothelium-removed aortic rings with wogonin
markedly reduced the contraction induced by 10-6 M PE in Ca2+-free solution. It could be concluded that L-type calcium
channels and intracellular Ca2+ release is inhibited by wogonin
The Protective Effect of Ligustilide in Osteoarthritis: An in Vitro and in Vivo Study
Background/Aims: Osteoarthritis is a degenerative joint disease characterized by cartilage degeneration and a chondrocyte inflammatory response that induces an inflammatory environment closely linked to extracellular matrix (ECM) degradation. Ligustilide (LIG) is a major component of the herb Radix Angelicae Sinensis, with demonstrated anti-inflammatory effects. To confirm whether LIG has an equally inhibitory effect on inflammation in human osteoarthritis chondrocytes, we performed in vivo and in vitro experiments to validate the above conjectures and determine the relevant mechanisms. Methods: Quantitative realtime PCR and western blotting were performed to evaluate the expression of MMP-3, MMP-13, ADAMTS-5, iNOS, and COX-2 at both gene and protein levels. An enzyme-linked immunosorbent assay was used to evaluate the levels of other inflammatory factors (PGE2, TNF-α, and IL-6). The PI3K/AKT and nuclear factor kappa B (NF-κB) signaling pathways were also analyzed by western blotting, whereas immunofluorescence was used to assess the expression of collagen II and aggrecan. The in vitro effect of LIG was evaluated by intraperitoneal injection into a mouse osteoarthritis model induced by destabilization of the medial meniscus. Results: LIG lowered the phosphorylation levels of p65, IκBα, and IKKα/β and suppressed the IL-1β-induced expression of MMP-3, ADAMTS-5, iNOS, and COX-2 and the inflammatory factors PGE2, TNF-α, and IL-6. LIG markedly decreased IL-1β-induced degradation of collagen II and aggrecan. In vivo results showed that LIG-treated mouse cartilage showed less damage than the control group; the Osteoarthritis Research Society International (OARSI) score was also lower. LIG further reduced the thickness of the subchondral bone plate and alleviated the synovitis. Conclusion: LIG may act as a promising therapeutic agent for osteoarthritis by attenuating IL-1β-induced inflammation in chondrocytes and ECM degradation via suppression of NF-κB activation by the PI3K/AKT pathway
Mechanistic study of endothelium independent vasodilation effects of wogonin
Scutellaria baicalensis Georgi, locally known as HuangQin, and commonly as Baikal or Chinese skullcap, is an important herb in Chinese traditional medicine. The flavonoids from this plant are main active substances responsible for its medicinal applications. Wogonin is one such active ingredient derived from this plant. Here, we investigated the mechanism of the vasodilation effect of wogonin on isolated rat thoracic aortas. For this study, endothelium intact and endothelium removed thoracic aortic rings were prepared from rats. Using a tension transducer, the tension of the rat thoracic aortic rings was recorded. Results showed that wogonin is able to relax the endothelium-intact aortic rings, but L-NAME, indomethacin (Indo), and methylene blue (MB) could not reduce the tension in these rings. Wogonin was also able to relax endotheliumremoved rings. However, treatment with tetraethylammonium (TEA), BaCl2, glibenclamide (Gly), 4-aminopyridine (4-AP), and verapamil (Ver) had no effect on vasodilation induced by wogonin. Using wogonin to pre-treat endothelium-removed aortic rings reduced the contraction induced by K+. Pre-treatment of endothelium-removed aortic rings with wogonin markedly reduced the contraction induced by 10-6 M PE in Ca2+-free solution. It could be concluded that L-type calcium channels and intracellular Ca2+ release is inhibited by wogonin
A predictive energy management strategy for multi-mode plug-in hybrid electric vehicles based on multi neural networks
Online optimal energy management of plug-in hybrid electric vehicles has been continually investigated for better fuel economy. This paper proposed a predictive energy management strategy based on multi neural networks for a multi-mode plug-in hybrid electric vehicle. To attain it, firstly, the offline optimal results prepared for knowledge learning are derived by dynamic programming and Pontryagin’s minimum principle. Then, the mode recognition neural network is trained based on the optimal results of dynamic programming and the recurrent neural network is firstly exploited to realize online co-state estimation application. Consequently, the velocity prediction-based online model predictive control framework is established with the co-state correction and slacked constraints to solve the real-time optimal control sequence. A series of numerical simulation results validate that the optimal performance yielded from global optimal strategy can be exploited online to attain the satisfied cost reduction, compared with equivalent consumption minimum strategy, with the assistance of estimated real time co-state and slacked reference. In addition, the computation duration of proposed algorithm decreases by 23.40%, compared with conventional Pontryagin’s minimum principle-based model predictive control scheme, thereby proving its online application potential
Lineage-specific accelerated sequences underlying primate evolution
Understanding the mechanisms underlying phenotypic innovation is a key goal of comparative genomic studies. Here, we investigated the evolutionary landscape of lineage-specific accelerated regions (LinARs) across 49 primate species. Genomic comparison with dense taxa sampling of primate species significantly improved LinAR detection accuracy and revealed many novel human LinARs associated with brain development or disease. Our study also yielded detailed maps of LinARs in other primate lineages that may have influenced lineage-specific phenotypic innovation and adaptation. Functional experimentation identified gibbon LinARs, which could have participated in the developmental regulation of their unique limb structures, whereas some LinARs in the Colobinae were associated with metabolite detoxification which may have been adaptive in relation to their leaf-eating diet. Overall, our study broadens knowledge of the functional roles of LinARs in primate evolution
Searching for the nano-Hertz stochastic gravitational wave background with the Chinese Pulsar Timing Array Data Release I
Observing and timing a group of millisecond pulsars (MSPs) with high
rotational stability enables the direct detection of gravitational waves (GWs).
The GW signals can be identified from the spatial correlations encoded in the
times-of-arrival of widely spaced pulsar-pairs. The Chinese Pulsar Timing Array
(CPTA) is a collaboration aiming at the direct GW detection with observations
carried out using Chinese radio telescopes. This short article serves as a
`table of contents' for a forthcoming series of papers related to the CPTA Data
Release 1 (CPTA DR1) which uses observations from the Five-hundred-meter
Aperture Spherical radio Telescope (FAST). Here, after summarizing the time
span and accuracy of CPTA DR1, we report the key results of our statistical
inference finding a correlated signal with amplitude \log A_{\rm c}= -14.4
\,^{+1.0}_{-2.8} for spectral index in the range of
assuming a GW background (GWB) induced quadrupolar correlation. The search for
the Hellings-Downs (HD) correlation curve is also presented, where some
evidence for the HD correlation has been found that a 4.6- statistical
significance is achieved using the discrete frequency method around the
frequency of 14 nHz. We expect that the future International Pulsar Timing
Array data analysis and the next CPTA data release will be more sensitive to
the nHz GWB, which could verify the current results.Comment: 18 pages, 6 figures, submitted to "Research in astronomy and
astrophysics" 22nd March 202
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