1,209 research outputs found

    Dynamics of quantum entanglement in the reservoir with memory effects

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    The non-Markovian dynamics of quantum entanglement is studied by the Shabani-Lidar master equation when one of entangled quantum systems is coupled to a local reservoir with memory effects. The completely positive reduced dynamical map can be constructed in the Kraus representation. Quantum entanglement decays more slowly in the non-Markovian environment. The decoherence time for quantum entanglement can be markedly increased by the change of the memory kernel. It is found out that the entanglement sudden death between quantum systems and entanglement sudden birth between the system and reservoir occur at different instants.Comment: 14 pages, 3 figure

    Detection of lymphangiogenesis in non-small cell lung cancer and its prognostic value

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    <p>Abstract</p> <p>Background</p> <p>Our aim was to detect lymphatic endothelial marker podoplanin, lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and vascular endothelial growth factor receptor-3 (VEGFR)-3 and study the prognostic relevance of lymphangiogenesis in non-small cell lung cancer (NSCLC).</p> <p>Materials</p> <p>82 paraffin-embedded tissues and 40 fresh frozen tissues from patients with NSCLC were studied. Tumor samples were immunostained for the lymphatic endothelial markers. Lymphangiogenesis was assessed by immunohistochemical double stains for Podoplanin and Ki-67. The prognostic relevance of lymphangiogenesis-related clinicopathological parameters in NSCLC was evaluated.</p> <p>Results</p> <p>We found that the number of podoplanin positive vessels was correlated positively with the number of LYVE-1 positive vessels. Most of VEGFR-3 positive, few of LYVE-1 positive and none of podoplanin positive vessels were blood vessels. Peritumoral lymphatic vessel density (ptLVD), pathologic stage, lymph node status, lymphatic vessel invasion (LVI), vascular endothelial growth factor-C (VEGF-C) expression and Ki-67 index of the endothelium cells of the micro lymphatic vessels (Ki67%) were associated significantly with a higher risk of tumor progress. ptLVD, pathologic stage, lymph-node metastasis and Ki67% were independent prognostic parameters for overall survival.</p> <p>Conclusion</p> <p>Podoplanin positive ptLVD might play important roles in the lymphangiogenesis and progression of NSCLC. Patients with high podoplanin+ ptLVD have a poor prognosis.</p

    Changes of outer retinal thickness with increasing age in normal eyes

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    AIM:To comprehensively investigate the relationship between outer retinal layer thickness and age in normal eyes.METHODS: One hundred normal eyes of 100 subjects who underwent spectral-domain optical coherence tomography(SD-OCT)were included in this retrospective study. The distances between the external limiting membrane(ELM)line and the photoreceptor inner segment/outer segment(IS/OS)line(ELM-IS/OS), the IS/OS line and the cone outer segment tips(COST)line(IS/OS-COST), the COST line and the retinal pigment epithelium(RPE)complex(COST-RPE)and the full retinal thickness(RT)were measured at the fovea and on four quarters. The relationship between thickness and age or sex was then analysed.RESULTS: A thinner RT was observed in women in a multiple regression analysis(men: 234.47±16.79 μm; women: 223.13±15.43 μm). The RT on the nasal quarter and the ELM-IS/OS thickness at the fovea and on the four quarters were significantly and negatively correlated with age. The IS/OS-COST and COST-RPE thicknesses at the fovea and on the four quarters were not significantly correlated with age or sex, respectively. The RT at the fovea was significantly thinner than on the four quarters. The ELM-IS/OS, IS/OS-COST and COST-RPE thicknesses at the fovea were significantly thicker than on the four quarters. CONCLUSION: In normal eyes, the RT thickness on the nasal quarter and the ELM-IS/OS thickness were significantly and negatively correlated with age. The IS/OS-COST and COST-RPE thicknesses were not significantly correlated with age or sex

    Realization of exceptional points along a synthetic orbital angular momentum dimension

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    Exceptional points (EPs), at which more than one eigenvalue and eigenvector coalesce, are unique spectral features of Non-Hermiticity (NH) systems. They exist widely in open systems with complex energy spectra. We experimentally demonstrate the appearance of paired EPs in a periodical driven degenerate optical cavity along the synthetic orbital angular momentum (OAM) dimension with a tunable parameter. The complex-energy band structures and the key features of EPs, i.e. their Fermi arcs, parity-time symmetry breaking transition, energy swapping, and half-integer band windings are directly observed by detecting the cavity's transmission spectrum. Our results advance the fundamental understanding of NH physics and demonstrate the flexibility of using the photonic synthetic dimensions to implement NH systems

    Parent-adolescent interaction and risk of adolescent internet addiction: a population-based study in Shanghai

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    Abstract Background Family-based intervention is essential for adolescents with behavioral problems. However, limited data are available on the relationship between family-based factors and adolescent internet addiction (AIA). We aimed to examine this relationship using a representative sample of Shanghai adolescents. Methods In October 2007, a total of 5122 adolescents were investigated from 16 high schools via stratified-random sampling in Shanghai. Self-reported and anonymous questionnaires were used to assess parent-adolescent interaction and family environments. AIA was assessed by DRM-52 Scale, developed from Young’s Internet-addiction Scale, using seven subscales to evaluate psychological symptoms of AIA. Results Adjusting for adolescents’ ages, genders, socio-economic status, school performances and levels of the consumption expenditure, strong parental disapproval of internet-use was associated with AIA (vs. parental approval, OR = 2.20, 95% CI: 1.24-3.91). Worse mother-adolescent relationships were more significantly associated with AIA (OR = 3.79, 95% CI: 2.22-6.48) than worse father-adolescent relationships (OR = 1.76, 95% CI: 1.10-2.80). Marital status of “married-but-separated” and family structure of “left-behind adolescents” were associated with symptoms of some subscales. When having high monthly allowance, resident students tended to develop AIA but commuter students did not. Family social-economic status was not associated with the development of AIA. Conclusions The quality of parent-adolescent relationship/communication was closely associated with the development of AIA, and maternal factors were more significantly associated with development of AIA than paternal factors. Family social-economic status moderated adolescent internet-use levels but not the development of AIA.http://deepblue.lib.umich.edu/bitstream/2027.42/109471/1/12888_2014_Article_1616.pd
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