577 research outputs found
Skyrmion Excitation in Two-Dimensional Spinor Bose-Einstein Condensate
We study the properties of coreless vortices(skyrmion) in spinor
Bose-Einstein condensate. We find that this excitation is always energetically
unstable, it always decays to an uniform spin texture. We obtain the skyrmion
energy as a function of its size and position, a key quantity in understanding
the decay process. We also point out that the decay rate of a skyrmion with
high winding number will be slower. The interaction between skyrmions and other
excitation modes are also discussed.Comment: 5 pages, 4 figures, final version published in Phys. Rev.
Strategy and Long-term Outcomes of Endovascular Treatment for Budd–Chiari Syndrome Complicated by Inferior Vena Caval Thrombosis
ObjectivesThe aim of this study was to evaluate the strategy and long-term outcomes of endovascular treatment of Budd–Chiari syndrome (BCS) complicated by inferior vena cava (IVC) thrombosis.MethodsThe treatment strategy and outcomes of BCS complicated by IVC thrombosis were retrospectively evaluated in a single-center study. The treatment was aimed at the IVC thrombus, not hepatic vein occlusion. All 133 patients with BCS complicated by IVC thrombosis from February 2003 to March 2013 underwent endovascular treatment. For the fresh thrombus group (n = 75) recanalization was performed after transcatheter thrombolysis with urokinase. For the mixed thrombus group (n = 19) a small balloon pre-dilation of the IVC was performed first, followed by transcatheter thrombolysis using urokinase and a large balloon dilation of the IVC. For the old thrombus group (n = 39) a large balloon dilation or/and stent placement was performed directly. Pre- and post-treatment follow-ups were recorded.ResultsThe endovascular treatment was successful in 131 out of 133 patients (98.5%). Thirty seven patients had synchronous hepatic vein occlusion. The incidence of serious complications was 4.5% (6/133). Symptomatic pulmonary embolism occurred in three cases, cerebral hemorrhage in two, and cardiac tamponade in one. The cumulative 1-, 5-, and 10-year primary patency rate was 96.3%, 84.0%, and 64.6%, respectively. The cumulative 1-, 5-, and 10-year secondary patency rate was 99.0%, 96.1% and 91.3%, respectively. Segmental occlusion of the IVC and duration of anticoagulant therapy less than 6 months were independent risk factors for reocclusion.ConclusionsFor patients with BCS complicated by IVC thrombosis, an individualized treatment strategy based on the property of the thrombus can result in excellent long-term patency
Shot noise of coupled semiconductor quantum dots
The low-frequency shot noise properties of two electrostatically coupled
semiconductor quantum dot states which are connected to emitter/collector
contacts are studied. A master equation approach is used to analyze the bias
voltage dependence of the Fano factor as a measure of temporal correlations in
tunneling current caused by Pauli's exclusion principle and the Coulomb
interaction. In particular, the influence of the Coulomb interaction on the
shot noise behavior is discussed in detail and predictions for future
experiments will be given. Furthermore, we propose a mechanism for negative
differential conductance and investigate the related super-Poissonian shot
noise.Comment: submitted to PR
Heart rate variability and peripheral nerve conduction velocity in relation to blood lead in newly hired lead workers.
Previous studies relating nervous activity to blood lead (BL) levels have limited relevance, because over time environmental and occupational exposure substantially dropped. We investigated the association of heart rate variability (HRV) and median nerve conduction velocity (NCV) with BL using the baseline measurements collected in the Study for Promotion of Health in Recycling Lead (NCT02243904).
In 328 newly hired men (mean age 28.3 years; participation rate 82.7%), we derived HRV measures (power expressed in normalised units (nu) in the high-frequency (HF) and low-frequency (LF) domains, and LF/HF) prior to long-term occupational lead exposure. Five-minute ECG recordings, obtained in the supine and standing positions, were analysed by Fourier transform or autoregressive modelling, using Cardiax software. Motor NCV was measured at the median nerve by a handheld device (Brevio Nerve Conduction Monitoring System, NeuMed, West Trenton, NJ, USA). BL was determined by inductively coupled plasma mass spectrometry.
Mean BL was 4.54 µg/dL (IQR 2.60-8.90 µg/dL). Mean supine and standing values of LF, HF and LF/HF were 50.5 and 21.1 nu and 2.63, and 59.7 and 10.9 nu and 6.31, respectively. Orthostatic stress decreased HF and increased LF (p<0.001). NCV averaged 3.74 m/s. Analyses across thirds of the BL distribution and multivariable-adjusted regression analyses failed to demonstrate any association of HRV or NCV with BL.
At the exposure levels observed in our study, autonomous nervous activity and NCV were not associated with BL.
NCT02243904
Dissipation and noise in adiabatic quantum pumps
We investigate the distribution function, the heat flow and the noise
properties of an adiabatic quantum pump for an arbitrary relation of pump
frequency and temperature. To achieve this we start with the
scattering matrix approach for ac-transport. This approach leads to expressions
for the quantities of interest in terms of the side bands of particles exiting
the pump. The side bands correspond to particles which have gained or lost a
modulation quantum . We find that our results for the pump
current, the heat flow and the noise can all be expressed in terms of a
parametric emissivity matrix. In particular we find that the current
cross-correlations of a multiterminal pump are directly related a to a
non-diagonal element of the parametric emissivity matrix. The approach allows a
description of the quantum statistical correlation properties (noise) of an
adiabatic quantum pump
Characterization of starch synthetic genes and starch granule during seeds development between synthetic hexaploid wheat and its parents
To study the development of starch granules in polyploid wheats, we investigated the expression of starch synthetic genes between the synthetic hexaploid wheat SHW-L1, its parents T. turgidum AS2255 and diploid Ae. tauschii AS60. The synthetic hexaploid wheat SHW-L1 showed significantly higher starch content and grain weight than its parents. Scanning electron microscopy (SEM) showed that SHW-L1 rapidly developed starch granules than AS2255 and AS60. The amount of B-type granule in AS60 was less than that in SHW-L1 and AS2255. RT-qPCR result showed that the starch synthetic genes AGPLSU1, AGPLSU2, AGPSSU1, AGPSSU2, GBSSI, SSIII, PHO1 and PHO2 expressed at earlier stages with larger quantity in SHW-L1 than in its parents during wheat grain development. The expression of the above mentioned genes in AS60 was slower than in SHW-L1 and AS2255. The expression pattern of starch synthase genes was also associated with the grain weight and starch content in all three genotypes. The results suggested that the synthetic hexaploid wheat inherited the pattern of starch granule development and starch synthase gene expression from tetraploid parent. The results suggest that tetraploid wheat could plays more important role for starch quality improvement in hexaploid wheat
Shot noise in normal metal-d-wave superconducting junctions
We present theoretical calculations and predictions for the shot noise in
voltage biased junctions of superconductors and normal metal
counter-electrodes. In the clean limit for the d-wave superconductor the shot
noise vanishes at zero voltage because of resonant Andreev reflection by
zero-energy surface bound states. We examine the sensitivity of this resonance
to impurity scattering. We report theoretical results for the magnetic field
dependence of the shot noise, as well the fingerprints of subdominant - and
pairing channels.Comment: 15 pages, 8 figures and 3 tables embedde
Diagnostic for Dilaton Dark Energy
diagnostic can differentiate between different models of dark energy
without the accurate current value of matter density. We apply this geometric
diagnostic to dilaton dark energy(DDE) model and differentiate DDE model from
LCDM. We also investigate the influence of coupled parameter on the
evolutive behavior of with respect to redshift . According to the
numerical result of , we get the current value of equation of state
=-0.952 which fits the WMAP5+BAO+SN very well.Comment: 6 pages and 6 figures
Synovial Fluid Fatty Acid Profiles Differ between Osteoarthritis and Healthy Patients
Objective: Free fatty acids (FAs) may influence cartilage metabolism and osteoarthritis (OA) disease progression. It is not clearly studied which FAs are present in the synovial fluid of knee joints and whether there are differences in FA content between nonsymptomatic and OA knee joints. The aim of this study was to investigate the presence of different types of FAs in synovial fluid of both OA- and nonsymptomatic control joints, and to analyze differences between both groups. Design: A total of 23 synovial fluid samples were collected from patients with end-stage knee OA undergoing total knee replacement, with approval of the medical ethical committee. As controls, 6 synovial fluid
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