754 research outputs found

    Quantum frequency conversion and single-photon detection with lithium niobate nanophotonic chips

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    In the past few years, the lithium niobate on insulator (LNOI) platform has revolutionized lithium niobate materials, and a series of quantum photonic chips based on LNOI have shown unprecedented performances. Quantum frequency conversion (QFC) photonic chips, which enable quantum state preservation during frequency tuning, are crucial in quantum technology. In this work, we demonstrate a low-noise QFC process on an LNOI nanophotonic platform designed to connect telecom and near-visible bands with sum-frequency generation by long-wavelength pumping. An internal conversion efficiency of 73% and an on-chip noise count rate of 900 counts per second (cps) are achieved. Moreover, the on-chip preservation of quantum statistical properties is verified, showing that the QFC chip is promising for extensive applications of LNOI integrated circuits in quantum information. Based on the QFC chip, we construct an upconversion single-photon detector with the sum-frequency output spectrally filtered and detected by a silicon single-photon avalanche photodiode, demonstrating the feasibility of an upconversion single-photon detector on-chip with a detection efficiency of 8.7% and a noise count rate of 300 cps. The realization of a low-noise QFC device paves the way for practical chip-scale QFC-based quantum systems in heterogeneous configurations.Comment: 8pages, 6 figures, 1 tabl

    Co/Pt Multilayers on Self-Organized Hexagonal Patterned Nanodots

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    Anodic alumina with surface of hexagonal patterned nanodots was prepared by a two-step anodizing procedure. Scanning electron microscope and atomic force microscopy results clearly showed the formation of self-organized hexagonal patterned nanostructure. Diameters of the nanodots were controlled by choosing different anodization voltage and types of electrolyte acids. Co/Pt multilayers deposited on the nanodots with different diameters of 20, 70, and 100 nm lead to the formation of magnetic nanostructures with perpendicular anisotropy. Magnetometry and the first-order reversal curve method were used to study the magnetic properties of Co/Pt nanostructures. An out-of-plane magnetic easy axis was observed for the continuous films and the nanodots with diameters of 100 and 70 nm. The magnetic multilayers deposited on 20 nm nanodots appeared to have taken on a hard axis type behavior. The curvature of nanodot arrays induces strong modifications on the magnetic properties of the nanostructures

    The Role of RhoA in Neovascular-Related Functions of Endothelial Progenitor Cells Induced by Angiotensinâ…¡

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    Background/Aims: Interference with endothelial progenitor cell (EPC) neovascularization is a novel therapeutic target for neovascular-related diseases. Angiotensin â…¡ (Ang â…¡) was found to enhance new vessel formation and aggravated neovascular-related diseases. In this study, we investigated the effects of Ang â…¡ on EPC neovascular-related functions and explored the underlying mechanisms. Methods: EPCs were cultured from bone marrow derived mononuclear cells. The effects of Ang â…¡ on EPC proliferation, adhesion, migration, and in vitro tube formation were investigated using the MTT assay, adhesion assay, transwell chamber assay, and in vitro tube formation assay respectively. The underlying mechanisms were explored using Western blotting assay. Results: EPC adhesion, migration and in vitro tube formation were promoted by Ang â…¡, and the effects were reversed by RhoA/Rho-associated kinases (ROCK) signaling pathway inhibitors including C3 exoenzyme, GGTI-286 and Y-27632. The active form of RhoA was up-regulated by Ang â…¡ and this effect was abolished by C3 exoenzyme. Moreover, RhoA silencing resulted in a notable inhibition of EPC adhesion, migration and in vitro tube formation, suggesting that RhoA activation played a pivotal role in Ang â…¡ angiogenic effect. The results also demonstrated that phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun-NH2 kinase was elevated by Ang â…¡ and attenuated by C3 exoenzyme, GGTI-286 and Y-27632. The enhancing effects of Ang â…¡ on EPC adhesion, migration and in vitro vasculogenesis were reversed by p38 inhibitor SB202190 and JNK inhibitor SP600125. Conclusion: Ang â…¡ may enhance EPC neovascular-related functions through activating RhoA/ ROCK and MAPK signaling pathway

    Improved Spatial Resolution Achieved by Chromatic Intensity Interferometry

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    Interferometers are widely used in imaging technologies to achieve enhanced spatial resolution, but require that the incoming photons be indistinguishable. In previous work, we built and analyzed color erasure detectors which expand the scope of intensity interferometry to accommodate sources of different colors. Here we experimentally demonstrate how color erasure detectors can achieve improved spatial resolution in an imaging task, well beyond the diffraction limit. Utilizing two 10.9 mm-aperture telescopes and a 0.8 m baseline, we measure the distance between a 1063.6 nm source and a 1064.4 nm source separated by 4.2 mm at a distance of 1.43 km, which surpasses the diffraction limit of a single telescope by about 40 times. Moreover, chromatic intensity interferometry allows us to recover the phase of the Fourier transform of the imaged objects - a quantity that is, in the presence of modest noise, inaccessible to conventional intensity interferometry.Comment: 5 pages, 3 figure

    Association of hematological parameters with metabolic syndrome in Beijing adult population: a longitudinal study

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    The purposes of the study were to estimate the incidence of metabolic syndrome (MetS) and to systematically evaluate the relationship between hematological parameters and MetS in a 5-year follow-up of Beijing adult population. The longitudinal study included 3,180 adults, aged 20–65 years, who attended health check-ups in Beijing Tongren Hospital in 2007 and 2012. Multivariate logistic regression was conducted to explore the associations between hematological parameters and MetS. The 5-year cumulative incidence of MetS in this sample was 10.82 % (14.22 % for males and 7.59 % for females). Among all the hematological parameters, white blood cell count (WBC) was positively associated with MetS for 20–35-year-old (male OR 1.482, 95 % CI 1.169–2.974; female OR 1.398, 95 % CI 1.145–3.011), and 36–50-year-old (male OR 2.012, 95 % CI 1.290–4.010; female OR 3.400, 95 % CI 1.818–4.528) male and female subjects. Alanine aminotransferase (ALT) was significantly associated with the incidence of MetS for males (20–35-year-old OR 2.080, 95 % CI 1.371–3.159; 36–50-year-old OR 2.421, 95 % CI 1.335–3.412; 51–65-year-old OR 4.267, 95 % CI 1.161–6.781). Low-density lipoprotein cholesterol (LDL-C) was positively associated with MetS for 51–65-year-old (male OR 3.078, 95 % CI 2.468–5.131; female OR 2.140, 95 %CI 1.524–4.359) for male and female subjects. WBC is positively associated with MetS for young adults, while LDL-C is positively associated with MetS for elderly people. ALT is positively associated with MetS for males. Our findings provide further evidence in support of using hematological markers for early detection of individuals at risk for MetS

    SP70 is a novel biomarker of hepatocellular carcinoma

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    BackgroundTumor-specific protein 70 (SP70) was identified as a new biomarker associated with the proliferation and invasion of cancer cells. This study aimed to investigate the expression of SP70 in hepatocellular carcinoma (HCC) and assess its clinical value in the diagnosis and prediction of early HCC recurrence.MethodsA total of 1049 subjects from the First Affiliated Hospital of Nanjing Medical University were recruited in this study. Serum SP70, alpha-fetoprotein (AFP) and prothrombin induced by vitamin K absence II (PIVKA-II) were measured. The diagnostic performance for HCC was obtained using the receiver operating characteristic (ROC) curve, and recurrence-free survival (RFS) was calculated using the Kaplan–Meier method. Univariate and multivariate analyses were performed to identify predictive factors of RFS.ResultsSP70 was highly expressed in HCC cells and HCC tissue. Serum SP70 levels in the HCC group were significantly higher than in the benign liver diseases group and healthy control group (P<0.001). SP70 combined with AFP showed the best diagnostic performance (AUC=0.909, 95%CI [confidence interval]=0.890–0.929). Kaplan–Meier analysis revealed that patients with high SP70 levels had shorter median RFS than those with low SP70 levels (P=0.003). In addition, high SP70 levels were significantly associated with shorter RFS (P=0.037) in the AFP-negative subgroup. Univariate and multivariate analyses confirmed that preoperative serum SP70 level, serum AFP, tumor diameter and microvascular invasion were independent prognostic factors of RFS.ConclusionSP70 is a promising biomarker in diagnosing HCC. High preoperative serum SP70 level is associated with an increased risk of early relapse and could be used as a valuable marker to predict early recurrence of HCC after resection
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