1,574 research outputs found

    Scalable Bell inequalities for multiqubit systems

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    Based on Clauser-Horner-Shimony-Holt inequality, we show a fruitful method to exploit Bell inequalities for multipartite qubit systems. These Bell inequalities are designed with a simpler architecture tailored to experimental demonstration. Under the optimal setting we derive a set of compact Mermin-type inequalities and discuss quantum violations for generalized Greenberger-Horne-Zeilinger (GGHZ) states. Also, we reveal relationship between quantum nonlocality and four-partite entanglement for four-qubit GGHZ states.Comment: 4 pages, 1 figur

    Evolution of Interlayer Coupling in Twisted MoS2 Bilayers

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    Van der Waals (vdW) coupling is emerging as a powerful method to engineer and tailor physical properties of atomically thin two-dimensional (2D) materials. In graphene/graphene and graphene/boron-nitride structures it leads to interesting physical phenomena ranging from new van Hove singularities1-4 and Fermi velocity renormalization5, 6 to unconventional quantum Hall effects7 and Hofstadter's butterfly pattern8-12. 2D transition metal dichalcogenides (TMDCs), another system of predominantly vdW-coupled atomically thin layers13, 14, can also exhibit interesting but different coupling phenomena because TMDCs can be direct or indirect bandgap semiconductors15, 16. Here, we present the first study on the evolution of interlayer coupling with twist angles in as-grown MoS2 bilayers. We find that an indirect bandgap emerges in bilayers with any stacking configuration, but the bandgap size varies appreciably with the twist angle: it shows the largest redshift for AA- and AB-stacked bilayers, and a significantly smaller but constant redshift for all other twist angles. The vibration frequency of the out-of-plane phonon in MoS2 shows similar twist angle dependence. Our observations, together with ab initio calculations, reveal that this evolution of interlayer coupling originates from the repulsive steric effects, which leads to different interlayer separations between the two MoS2 layers in different stacking configurations

    A scalable tripartite Wigner's friend scenario

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    Wigner's friend thought experiment is intended to reveal the inherent tension between unitary evolution and measurement collapse. On the basis of Wigner's friend experiment, Brukner derives a no-go theorem for observer-independent facts. We construct an extended Wigner's friend scenario including three laboratories, namely, Alice's laboratory, Bob's laboratory and Charlie's laboratory, where Alice, Bob and Charlie are standing outside the laboratories while their friends are placed inside their own laboratories. We consider quantum simulation via Q\# quantum programming and also realize the primary quantum circuits using IBM quantum computers. Then, we calculate the probabilities and corresponding statistical uncertainties. It has been shown that the results of quantum simulation are clearly consistent with theoretical values, while it has a slightly higher error rates for the experimental results of quantum computers mainly because of a series of quantum gates, especially CNOT gates.Comment: 8 pages, 8 figure

    Pulse Width Modulation Electro-Acupuncture on Cardiovascular Remodeling and Plasma Nitric Oxide in Spontaneously Hypertensive Rats

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    This study was designed to investigate the effect of pulse width modulation electro-acupuncture (PWM-EA) on cardiovascular remodeling and nitric oxide (NO) in spontaneously hypertensive rats (SHR). Thirty-four male SHR were randomly divided into control, captopril, and two PWM-EA groups, which were treated with 350 Hz (SHR-350 Hz) and whole audio bandwith electro-acupuncture (SHR-WAB group) respectively, on the ST 36 point located on the outside of the hind leg. Systolic blood pressure (BP), plasma and myocardial NO were measured. Histological studies were also performed on the aortic wall and the left ventricle. The BP in the SHR-350 Hz, SHR-WAB and the captopril groups was lower than in the control group following the treatment (P < .05). The average aortic media wall thickness in the two electro-acupuncture groups was less than in the control group (P < .05). The left ventricle/heart weight ratio in the captopril and SHR-350 Hz groups was less than in the control group (P < .01), but was similar between the SHR-WAB and the control group (P > .05). The plasma and myocardium NO levels were elevated in the captopril and the SHR-350 Hz group (P < .05 and .01, resp.). The plasma level of NO in the SHR-WAB group was also higher than in the control group (P < .05). We concluded that pulse width modulation electro-acupuncture on the ST 36 point prevents the progression of hypertension and diminishes the cardiovascular remodeling in SHR. It also elevates plasma and cardiac NO in this animal model

    Two Photon Decays of Ρc\eta_c from Lattice QCD

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    We present an exploratory lattice study for the two-photon decay of ηc\eta_c using Nf=2N_f=2 twisted mass lattice QCD gauge configurations generated by the European Twisted Mass Collaboration. Two different lattice spacings of a=0.067a=0.067fm and a=0.085a=0.085fm are used in the study, both of which are of physical size of 2fmfm. The decay widths are found to be 1.025(5)1.025(5)KeV for the coarser lattice and 1.062(5)1.062(5)KeV for the finer lattice respectively where the errors are purely statistical. A naive extrapolation towards the continuum limit yields Γ≃1.122(14)\Gamma\simeq 1.122(14)KeV which is smaller than the previous quenched result and most of the current experimental results. Possible reasons are discussed.Comment: 13 pages, 7 figures; matches the published versio

    Molecules in the peculiar age-defying source IRAS 19312+1950

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    Context. IRAS 19312+1950 is an isolated infrared source that exhibits a characteristic quasi-point-symmetric morphology in the near- and mid-infrared images and is also very bright in molecular radio lines. Because of its unique observational characteristics, various observational studies have been conducted and several hypotheses have been proposed regarding its origin, which is still unclear. So far, it has been suggested that it could be a peculiar evolved star, a young stellar object, or even a red nova remnant. Regardless of which type of object it is ultimately classified as, IRAS 19312+1950 is exceptionally bright in the infrared and molecular radio lines and therefore will undoubtedly be crucial as a prototype of this kind of object having a peculiar nature or unusual evolutionary phase. Aims. This study aims to reveal the molecular composition of the central part of IRAS 19312+1950 by performing an unbiased molecular radio line survey and discussing the origin of the object from a molecular chemical point of view. Methods. We carried out a spectral line survey with the IRAM 30 m telescope towards the center of IRAS 19312+1950 in the 3 and 1.3 mm windows. Results. In total, 28 transition lines of 22 molecular species and those isotopologues are detected towards IRAS 19312+1950, some of which exhibit a broad and a narrow components. Seventeen thermal lines and 1 maser line are newly detected. The molecular species of C17^{17}O, 30^{30}SiO, HN13^{13}C, HC18^{18}O+^{+}, H2_{2}CO, and cc-C3_{3}H2_{2} are detected for the first time in this object. Conclusions. Our results, in combination with previous studies, favor the hypothesis that IRAS 19312+1950 might be a red nova remnant, in which the progenitors that merged to become a red nova may have contained at least two evolved stars with oxygen-rich and carbon-rich chemistry, respectively.Comment: 30 pages, 24 figures, accepted for publication in A&

    Population genetic structure of the deep‐sea mussel Bathymodiolus platifrons (Bivalvia: Mytilidae) in the Northwest Pacific

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    © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Evolutionary Applications 11 (2018): 1915-1930, doi:10.1111/eva.12696.Studying population genetics of deep‐sea animals helps us understand their history of habitat colonization and population divergence. Here, we report a population genetic study of the deep‐sea mussel Bathymodiolus platifrons (Bivalvia: Mytilidae) widely distributed in chemosynthesis‐based ecosystems in the Northwest Pacific. Three mitochondrial genes (i.e., atp6, cox1, and nad4) and 6,398 genomewide single nucleotide polymorphisms (SNPs) were obtained from 110 individuals from four hydrothermal vents and two methane seeps. When using the three mitochondrial genes, nearly no genetic differentiation was detected for B. platifrons in the Northwest Pacific. Nevertheless, when using SNP datasets, all individuals in the South China Sea (SCS) and three individuals in Sagami Bay (SB) together formed one genetic cluster that was distinct from the remaining individuals. Such genetic divergence indicated a genetic barrier to gene flow between the SCS and the open Northwest Pacific, resulting in the co‐occurrence of two cryptic semi‐isolated lineages. When using 125 outlier SNPs identified focusing on individuals in the Okinawa Trough (OT) and SB, a minor genetic subdivision was detected between individuals in the southern OT (S‐OT) and those in the middle OT (M‐OT) and SB. This result indicated that, although under the influence of the Kuroshio Current and the North Pacific Intermediate Water, subtle geographic barriers may exist between the S‐OT and the M‐OT. Introgression analyses based on these outlier SNPs revealed that Hatoma Knoll in the S‐OT represents a possible contact zone for individuals in the OT‐SB region. Furthermore, migration dynamic analyses uncovered stronger gene flow from Dai‐yon Yonaguni Knoll in the S‐OT to the other local populations, compared to the reverse directions. Taken together, the present study offered novel perspectives on the genetic connectivity of B. platifrons mussels, revealing the potential interaction of ocean currents and geographic barriers with adaption and reproductive isolation in shaping their migration patterns and genetic differentiation in the Northwest Pacific.General Research Fund Grant Number: HKBU12302917; Hong Kong Baptist University Grant Number: 15‐1012‐P0

    Bardoxolone methyl induces apoptosis and autophagy and inhibits epithelial-to-mesenchymal transition and stemness in esophageal squamous cancer cells

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    Natural and synthetic triterpenoids have been shown to kill cancer cells via multiple mechanisms. The therapeutic effect and underlying mechanism of the synthetic triterpenoid bardoxolone methyl (C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid; CDDO-Me) on esophageal cancer are unclear. Herein, we aimed to investigate the anticancer effects and underlying mechanisms of CDDO-Me in human esophageal squamous cell carcinoma (ESCC) cells. Our study showed that CDDO-Me suppressed the proliferation and arrested cells in G2/M phase, and induced apoptosis in human ESCC Ec109 and KYSE70 cells. The G2/M arrest was accompanied with upregulated p21Waf1/Cip1 and p53 expression. CDDO-Me significantly decreased B-cell lymphoma-extra large (Bcl-xl), B-cell lymphoma 2 (Bcl-2), cleaved caspase-9, and cleaved poly ADP ribose polymerase (PARP) levels but increased the expression level of Bcl-2-associated X (Bax). Furthermore, CDDO-Me induced autophagy in both Ec109 and KYSE70 cells via suppression of the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway. There were interactions between the autophagic and apoptotic pathways in Ec109 and KYSE70 cells subject to CDDO-Me treatment. CDDO-Me also scavenged reactive oxygen species through activation of the nuclear factor (erythroid-derived 2)-related factor 2 (Nrf2) pathway in Ec109 and KYSE70 cells. CDDO-Me inhibited cell invasion, epithelial-mesenchymal transition, and stemness in Ec109 and KYSE70 cells. CDDO-Me significantly downregulated E-cadherin but upregulated Snail, Slug, and zinc finger E-box-binding homeobox 1 (TCF-8/ZEB1) in Ec109 and KYSE70 cells. CDDO-Me significantly decreased the expression of octamer-4, sex determining region Y-box 2 (Sox-2), Nanog, and B lymphoma Mo-MLV insertion region 1 homolog (Bmi-1), all markers of cancer cell stemness, in Ec109 and KYSE70 cells. Taken together, these results indicate that CDDO-Me is a promising anticancer agent against ESCC. Further studies are warranted to explore the molecular targets, efficacy and safety of CDDO-Me in the treatment of ESCC
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