236 research outputs found

    Energy Spectra of Quantum Turbulence: Large-scale Simulation and Modeling

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    In 204832048^3 simulation of quantum turbulence within the Gross-Pitaevskii equation we demonstrate that the large scale motions have a classical Kolmogorov-1941 energy spectrum E(k) ~ k^{-5/3}, followed by an energy accumulation with E(k) ~ const at k about the reciprocal mean intervortex distance. This behavior was predicted by the L'vov-Nazarenko-Rudenko bottleneck model of gradual eddy-wave crossover [J. Low Temp. Phys. 153, 140-161 (2008)], further developed in the paper.Comment: (re)submitted to PRB: 5.5 pages, 4 figure

    Identification of intracellular squalene in living algae, Aurantiochytrium mangrovei with hyper-spectral coherent anti-Stokes Raman microscopy using a sub-nanosecond supercontinuum laser source

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    We applied hyper-spectral coherent anti-Stokes Raman scattering imaging to intracellular lipid identification in living microalgae, Aurantiochytrium mangrovei 18W-13a. Two different lipids, squalene and triacylglycerol, were found inside living cells with clear vibrational contrast. Based on the endogenous lipid band as a result of the cis C[DOUBLE BOND]C stretch vibrational mode, squalene and triacylglycerol were clearly distinguished in different intracellular areas. In particular, squalene was detected solely in vacuoles as lipid particles, which was also supported by electron microscopy

    Diamond-like carbon coating under oleic acid lubrication: Evidence for graphene oxide formation in superlow friction

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    International audienceThe achievement of the superlubricity regime, with a friction coefficient below 0.01, is the Holy Grail of many tribological applications, with the potential to have a remarkable impact on economic and environmental issues. Based on a combined high-resolution photoemission and soft X-ray absorption study, we report that superlubricity can be realized for engineering applications in bearing steel coated with ultra-smooth tetrahedral amorphous carbon (ta-C) under oleic acid lubrication. The results show that tribochemical reactions promoted by the oil lubrication generate strong structural changes in the carbon hybridization of the ta-C hydrogen-free carbon, with initially high sp 3 content. Interestingly, the macroscopic superlow friction regime of moving mechanical assemblies coated with ta-C can be attributed to a few partially oxidized graphene-like sheets, with a thickness of not more than 1 nm, formed at the surface inside the wear scar. The sp 2 planar carbon and oxygen-derived species are the hallmark of these mesoscopic surface structures created on top of colliding asperities as a result of the tribochemical reactions induced by the oleic acid lubrication. Atomistic simulations elucidate the tribo-formation of such graphene-like structures, providing the link between the overall atomistic mechanism and the macroscopic experimental observations of green superlubricity in the investigated ta-C/oleic acid tribological systems

    Trends in Head and Neck Cancer Mortality from 1999 to 2019 in Japan : An Observational Analysis

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    The number of cases of head and neck cancer (HNC) and related deaths has recently increased worldwide. To the best of our knowledge, few studies have examined crude or age-adjusted HNC mortality rates in Japan. Therefore, this study aimed to determine the trends in crude and age-adjusted mortality rates for HNC per million individuals in Japan from 1999 to 2019. In Japan, the number of HNC-related deaths increased 1.48-fold. Age-adjusted mortality rates for HNC were four times higher in men than in women, and the rates for both men and women decreased over the 21-year period. This study clarifies the changes in age-adjusted mortality rates of HNC in Japan over time and will aid in developing targeted screening and prevention programs for HNC.Globally, the numbers of head and neck cancer (HNC) cases and related deaths have recently increased. In Japan, few studies have examined crude or age-adjusted HNC mortality rates. Therefore, this study aimed to determine the trends in crude and age-adjusted mortality rates for HNC per million individuals in Japan from 1999 to 2019. Data on HNC-associated deaths were extracted from the national death certificate database using the International Classification of Diseases, Tenth Revision (n = 156,742). HNC mortality trends were analysed using joinpoint regression models to estimate annual percentage change (APC) and average APC (AAPC). Among men, no significant change was observed in the age-adjusted death rate trend from 1999 to 2014; however, a marked decrease was observed from 2014 to 2019. No changing point was observed in women. Age-adjusted mortality rates continuously decreased over the 21-year period, with an AAPC of −0.7% in men and −0.6% in women. In conclusion, the overall trend in age-adjusted rates of HNC-associated deaths decreased, particularly among men, in the past 5 years. These results will contribute to the formulation of medical policies to develop targeted screening and prevention programmes for HNC in Japan and determine the direction of treatment strategies
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