8,005 research outputs found
The Structure on Invariant Measures of generic diffeomorphisms
Let be an isolated non-trival transitive set of a generic
diffeomorphism f\in\Diff(M). We show that the space of invariant measures
supported on coincides with the space of accumulation measures of
time averages on one orbit. Moreover, the set of points having this property is
residual in (which implies the set of irregular points is also
residual in ). As an application, we show that the non-uniform
hyperbolicity of irregular points in with totally 0 measure
(resp., the non-uniform hyperbolicity of a generic subset in )
determines the uniform hyperbolicity of
The effects of the little Higgs models on production via collision at linear colliders
In the frameworks of the littlest Higgs() model and its extension with
T-parity(), we studied the associated production process at the future linear colliders
up to QCD next-to-leading order. We present the regions of
parameter space in which the and effects can and cannot be
discovered with the criteria assumed in this paper. The production rates of
process in different photon polarization
collision modes are also discussed. We conclude that one could observe the
effects contributed by the or model on the cross section for the
process in a reasonable parameter
space, or might put more stringent constraints on the / parameters in
the future experiments at linear colliders.Comment: 22 pages, 25 figures, version to appear in Phys. Rev.
Critical currents, flux-creep activation energy and potential barriers for the vortex motion from the flux creep experiments
We present an experimental study of thermally activated flux creep in a
superconducting ring-shaped epitaxial YBCO film as well as a new way of
analyzing the experimental data. The measurements were made in a wide range of
temperatures between 10 and 83 K. The upper temperature limit was dictated by
our experimental technique and at low temperatures we were limited by a
crossover to quantum tunneling of vortices. It is shown that the experimental
data can very well be described by assuming a simple thermally activated
hopping of vortices or vortex bundles over potential barriers, whereby the
hopping flux objects remain the same for all currents and temperatures. The new
procedure of data analysis also allows to establish the current and temperature
dependencies of the flux-creep activation energy U, as well as the temperature
dependence of the critical current Ic, from the flux-creep rates measured at
different temperatures. The variation of the activation energy with current,
U(I/Ic), is then used to reconstruct the profile of the potential barriers in
real space.Comment: 12 pages, 13 Postscript figures, Submitted to Physical Review
Anomalous Crossing Frequency in Odd Proton Nuclei
A generic explanation for the recently observed anomalous crossing
frequencies in odd proton rare earth nuclei is given. As an example, the proton
band in Ta is discussed in detail by using the
angular momentum projection theory. It is shown that the quadrupole pairing
interaction is decisive in delaying the crossing point and the changes in
crossing frequency along the isotope chain are due to the different neutron
shell fillings
Effect of gauge boson mass on the phase structure of QED
Dynamical chiral symmetry breaking (DCSB) in QED with finite gauge
boson mass is
studied in the framework of the rainbow approximation of Dyson-Schwinger
equations.
By adopting a simple gauge boson propagator ansatz at finite temperature, we
first numerically solve the
Dyson-Schwinger equation for the fermion self-energy to
determine the chiral phase diagram of QED with finite gauge boson mass
at finite chemical potential and finite temperature, then we study the
effect of the finite gauge mass on the phase diagram of QED. It is found
that the gauge boson mass suppresses the occurrence of
DCSB. The area of the region in the chiral phase diagram corresponding to
DCSB phase decreases as
the gauge boson mass increases. In
particular, chiral symmetry gets restored when is above a
certain critical value. In this paper, we use DCSB to describe the
antiferromagnetic order and use the gauge boson mass to describe the
superconducting order. Our results give qualitatively a physical
picture on the competition and coexistence between antiferromagnetic
order and superconducting orders in high temperature cuprate superconductors.Comment: 10 pages, 2 figure
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Anti-tat Hutat2:Fc mediated protection against tat-induced neurotoxicity and HIV-1 replication in human monocyte-derived macrophages
Background: HIV-1 Tat is essential for HIV replication and is also a well-known neurotoxic factor causing HIV-associated neurocognitive disorder (HAND). Currently, combined antiretroviral therapy targeting HIV reverse transcriptase or protease cannot prevent the production of early viral proteins, especially Tat, once HIV infection has been established. HIV-infected macrophages and glial cells in the brain still release Tat into the extracellular space where it can exert direct and indirect neurotoxicity. Therefore, stable production of anti-Tat antibodies in the brain would neutralize HIV-1 Tat and thus provide an effective approach to protect neurons. Methods: We constructed a humanized anti-Tat Hutat2:Fc fusion protein with the goal of antagonizing HIV-1 Tat and delivered the gene into cell lines and primary human monocyte-derived macrophages (hMDM) by an HIV-based lentiviral vector. The function of the anti-Tat Hutat2:Fc fusion protein and the potential side effects of lentiviral vector-mediated gene transfer were evaluated in vitro. Results: Our study demonstrated that HIV-1-based lentiviral vector-mediated gene transduction resulted in a high-level, stable expression of anti-HIV-1 Tat Hutat2:Fc in human neuronal and monocytic cell lines, as well as in primary hMDM. Hutat2:Fc was detectable in both cells and supernatants and continued to accumulate to high levels within the supernatant. Hutat2:Fc protected mouse cortical neurons against HIV-1 Tat86-induced neurotoxicity. In addition, both secreted Hutat2:Fc and transduced hMDM led to reducing HIV-1BaL viral replication in human macrophages. Moreover, lentiviral vector-based gene introduction did not result in any significant changes in cytomorphology and cell viability. Although the expression of IL8, STAT1, and IDO1 genes was up-regulated in transduced hMDM, such alternation in gene expression did not affect the neuroprotective effect of Hutat2:Fc. Conclusions: Our study demonstrated that lentivirus-mediated gene transfer could efficiently deliver the Hutat2:Fc gene into primary hMDM and does not lead to any significant changes in hMDM immune-activation. The neuroprotective and HIV-1 suppressive effects produced by Hutat2:Fc were comparable to that of a full-length anti-Tat antibody. This study provides the foundation and insights for future research on the potential use of Hutat2:Fc as a novel gene therapy approach for HAND through utilizing monocytes/macrophages, which naturally cross the blood-brain barrier, for gene delivery. Electronic supplementary material The online version of this article (doi:10.1186/s12974-014-0195-2) contains supplementary material, which is available to authorized users
Hawking-Page Phase Transition of black Dp-branes and R-charged black holes with an IR Cutoff
We show that the confinement-deconfinement phase transition of supersymmetric
Yang-Mills theories with 16 supercharges in various dimensions can be realized
through the Hawking-Page phase transition between the near horizon geometries
of black Dp-branes and BPS Dp-branes by removing a small radius region in the
geometry in order to realize a confinement phase, which generalizes the
Herzog's discussion for the holographic hard-wall AdS/QCD model. Removing a
small radius region in the gravitational dual corresponds to introducing an IR
cutoff in the dual field theory. We also discuss the Hawking-Page phase
transition between thermal , , spaces and R-charged AdS
black holes coming from the spherical reduction of the decoupling limit of
rotating D3-, M2-, and M5- branes in type IIB supergravity and 11 dimensional
supergravity in grand canonical ensembles, where the IR cutoff also plays a
crucial role in the existence of the phase transition.Comment: 34 pages, 18 figures, JHEP3, v2, references added, v3, some
explanations adde
Microwave plasma-assisted photoluminescence enhancement in nitrogendoped ultrananocrystalline diamond film
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Significance of Coronary Calcification for Prediction of Coronary Artery Disease and Cardiac Events Based on 64-Slice Coronary Computed Tomography Angiography
This work aims to validate the clinical significance of coronary artery calcium score (CACS) in predicting coronary artery disease(CAD) and cardiac events in 100 symptomatic patients (aged 37–87 years, mean 62.5, 81 males) that were followed up for a mean of 5 years. Our results showed that patients with CAD and cardiac events had significantly higher CACS than those without CAD and cardiac events, respectively. The corresponding data were 1450.42 ± 3471.24 versus 130 ± 188.29 (P 1000. Increased CACS (>100)was also associated with an increased frequency of multi-vessel disease. Nonetheless, 3 (20%) out of 15 patients with zero CACS had single-vessel disease. Significant correlation (P < 0.001) was observed between CACS and CAD on a vessel-based analysis for coronary arteries. It is concluded that CACS is significantly correlated with CAD and cardiac events
Nano-scale superhydrophobicity: suppression of protein adsorption and promotion of flow-induced detachment
Wall adsorption is a common problem in microfluidic devices, particularly when proteins are used. Here we show how superhydrophobic surfaces can be used to reduce protein adsorption and to promote desorption. Hydrophobic surfaces, both smooth and having high surface roughness of varying length scales (to generate superhydrophobicity), were incubated in protein solution. The samples were then exposed to flow shear in a device designed to simulate a microfluidic environment. Results show that a similar amount of protein adsorbed onto smooth and nanometer-scale rough surfaces, although a greater amount was found to adsorb onto superhydrophobic surfaces with micrometer scale roughness. Exposure to flow shear removed a considerably larger proportion of adsorbed protein from the superhydrophobic surfaces than from the smooth ones, with almost all of the protein being removed from some nanoscale surfaces. This type of surface may therefore be useful in environments, such as microfluidics, where protein sticking is a problem and fluid flow is present. Possible mechanisms that explain the behaviour are discussed, including decreased contact between protein and surface and greater shear stress due to interfacial slip between the superhydrophobic surface and the liquid
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