73,355 research outputs found

    Hemodynamic evaluation using four-dimensional flow magnetic resonance imaging for a patient with multichanneled aortic dissection

    Get PDF
    The hemodynamic function of multichanneled aortic dissection (MCAD) requires close monitoring and effective management to avoid potentially catastrophic sequelae. This report describes a 47-year-old man who underwent endovascular repair based on findings from four-dimensional (4D) flow magnetic resonance imaging of an MCAD. The acquired 4D flow data revealed complex, bidirectional flow patterns in the false lumens and accelerated blood flow in the compressed true lumen. The collapsed abdominal true lumen expanded unsatisfactorily after primary tear repair, which required further remodeling with bare stents. This case study demonstrates that hemodynamic analysis using 4D flow magnetic resonance imaging can help understand the complex pathologic changes of MCAD

    Variation in actual relationship among descendants of inbred individuals

    Get PDF
    In previous analyses, the variation in actual, or realized, relationship has been derived as a function of map length of chromosomes and type of relationship, the variation being greater the shorter the total chromosome length and the coefficient of variation being greater the more distant the relationship. Here, the results are extended to allow for the relatives' ancestor being inbred. Inbreeding of a parent reduces variation in actual relationship among its offspring, by an amount that depends on the inbreeding level and the type of mating that led to that level. For descendants of full-sibs, the variation is reduced in later generations, but for descendants of half-sibs, it is increased

    The short-time critical behaviour of the Ginzburg-Landau model with long-range interaction

    Full text link
    The renormalisation group approach is applied to the study of the short-time critical behaviour of the dd-dimensional Ginzburg-Landau model with long-range interaction of the form pσspspp^{\sigma} s_{p}s_{-p} in momentum space. Firstly the system is quenched from a high temperature to the critical temperature and then relaxes to equilibrium within the model A dynamics. The asymptotic scaling laws and the initial slip exponents θ\theta^{\prime} and θ\theta of the order parameter and the response function respectively, are calculated to the second order in ϵ=2σd\epsilon=2\sigma-d.Comment: 18 pages, 4 figures, 1 tabl

    Combinations of antioxidants and/or of epigenetic enzyme inhibitors allow for enhanced collection of mouse bone marrow hematopoietic stem cells in ambient air

    Get PDF
    Hematopoietic cell transplantation (HCT) is a treatment for malignant and non-malignant disorders. However, sometimes the numbers of donor hematopoietic stem cells (HSC) are limiting, which can compromise the success of HCT. We recently published that collection and processing of mouse bone marrow (BM) and human cord blood cells in a hypoxic atmosphere of 3% O2 or in ambient air (~21% O2) in the presence of cyclosporine A yields increased numbers of HSC. We now show that collection and processing of mouse BM cells in ambient air in the presence of specific combinations of anti-oxidants and/or inhibitors of epigenetic enzymes can also enhance the collection of HSC, information of potential relevance for enhanced efficacy of HCT

    C1-C8 volatile organic compounds in the atmosphere of Hong Kong: Overview of atmospheric processing and source apportionment

    Get PDF
    We present measurements of C1-C8 volatile organic compounds (VOCs) at four sites ranging from urban to rural areas in Hong Kong from September 2002 to August 2003. A total of 248 ambient VOC samples were collected. As expected, the urban and sub-urban sites generally gave relatively high VOC levels. In contrast, the average VOC levels were the lowest in the rural area. In general, higher mixing ratios were observed during winter/spring and lower levels during summer/fall because of seasonal variations of meteorological conditions. A variation of the air mass composition from urban to rural sites was observed. High ratios of ethyne/CO (5.6 pptv/ppbv) and propane/ethane (0.50 pptv/pptv) at the rural site suggested that the air masses over the territory were relatively fresh as compared to other remote regions. The principal component analysis (PCA) with absolute principal component scores (APCS) technique was applied to the VOC data in order to identify and quantify pollution sources at different sites. These results indicated that vehicular emissions made a significant contribution to ambient non-methane VOCs (NMVOCs) levels in urban areas (65±36%) and in sub-urban areas (50±28% and 53±41%). Other sources such as petrol evaporation, industrial emissions and solvent usage also played important roles in the VOC emissions. At the rural site, almost half of the measured total NMVOCs were due to combustion sources (vehicular and/or biomass/biofuel burning). Petrol evaporation, solvent usage, industrial and biogenic emissions also contributed to the atmospheric NMVOCs. The source apportionment results revealed a strong impact of anthropogenic VOCs to the atmosphere of Hong Kong in both urban/sub-urban and rural areas. © 2006 Elsevier Ltd. All rights reserved

    Possible Σ(12)\Sigma({1\over2}^-) under the Σ(1385)\Sigma^*(1385) peak in KΣK\Sigma^* photoproduction

    Full text link
    The LEPS collaboration has recently reported a measurement of the reaction γnK+Σ(1385)\gamma n\to K^+\Sigma^{*-}(1385) with linearly polarized photon beam at resonance region. The observed beam asymmetry is sizably negative at Eγ=1.82.4GeVE_\gamma=1.8-2.4 \mathrm{GeV}, in contrast to the presented theoretical prediction. In this paper, we calculate this process in the framework of the effective Lagrangian approach. By including a newly proposed Σ(JP=12)\Sigma(J^P={1\over2}^-) state with mass around 1380~MeV, the experimental data for both γn\gamma n and γp\gamma p experiments can be well reproduced. It is found that the Σ(12)\Sigma({1\over2}^-) and/or the contact term may play important role and deserve further investigation.Comment: modified version to be published at Phys. Rev.

    New molecular candidates: X(1910), X(2200), and X(2350)

    Full text link
    Assuming the newly observed resonant structures X(1910), X(2200), and X(2350) as ωω\omega\omega, ωϕ\omega\phi, and ϕϕ\phi\phi molecular states respectively, we compute their mass values in the framework of QCD sum rules. The numerical results are 1.97±0.17GeV1.97\pm0.17 {GeV} for ωω\omega\omega state, 2.07±0.21GeV2.07\pm0.21 {GeV} for ωϕ\omega\phi state, and 2.18±0.29GeV2.18\pm0.29 {GeV} for ϕϕ\phi\phi state, which coincide with the experimental values of X(1910), X(2200), and X(2350), respectively. This supports the statement that X(1910), X(2200), and X(2350) could be ωω\omega\omega, ωϕ\omega\phi, and ϕϕ\phi\phi molecular candidates respectively.Comment: 9 pages, 9 eps figures; the name of X(2000) changed to X(1910) according to the updated data of experiments; more references and discussions added; accepted for publication in PRD. arXiv admin note: substantial text overlap with arXiv:1211.2277, arXiv:1201.341

    Metastable helium molecules as tracers in superfluid liquid 4^{4}He

    Get PDF
    Metastable helium molecules generated in a discharge near a sharp tungsten tip operated in either pulsed mode or continuous field-emission mode in superfluid liquid 4^{4}He are imaged using a laser-induced-fluorescence technique. By pulsing the tip, a small cloud of He2_{2}^{*} molecules is produced. At 2.0 K, the molecules in the liquid follow the motion of the normal fluid. We can determine the normal-fluid velocity in a heat-induced counterflow by tracing the position of a single molecule cloud. As we run the tip in continuous field-emission mode, a normal-fluid jet from the tip is generated and molecules are entrained in the jet. A focused 910 nm pump laser pulse is used to drive a small group of molecules to the vibrational a(1)a(1) state. Subsequent imaging of the tagged a(1)a(1) molecules with an expanded 925 nm probe laser pulse allows us to measure the velocity of the normal fluid. The techniques we developed demonstrate for the first time the ability to trace the normal-fluid component in superfluid helium using angstrom-sized particles.Comment: 4 pages, 7 figures. Submitted to Phys. Rev. Let
    corecore