1,058 research outputs found
Strong quantum fluctuation of vortices in the new superconductor
By using transport and magnetic measurement, the upper critical field
and the irreversibility line has been determined. A
big separation between and has been found showing the
existence of a quantum vortex liquid state induced by quantum fluctuation of
vortices in the new superconductor . Further investigation on the
magnetic relaxation shows that both the quantum tunneling and the thermally
activated flux creep weakly depends on temperature. But when the melting field
is approached, a drastic rising of the relaxation rate is observed.
This may imply that the melting of the vortex matter at a finite temperature is
also induced by the quantum fluctuation of vortices.Comment: 4 pages, 4 figure
Superluminal Behaviors of Modified Bessel Waves
Much experimental evidence of superluminal phenomena has been available by
electromagnetic wave propagation experiments, with the results showing that the
phase time do describe the barrier traversal time. Based on the extrapolated
phase time approach and numerical methods, we show that, in contrary to the
ordinary Bessel waves of real argument, the group velocities of modified Bessel
waves are superluminal, and obtain the following results: 1) the group
velocities increase with the increase of propagation distance, which is similar
to the evanescent plane-wave cases; 2) for large wave numbers, the group
velocities fall off as the wave numbers increase, which is similar to the
evanescent plane-wave cases; 3) for small wave numbers, the group velocities
increase with the increase of wave numbers, this is different from the
evanescent plane-wave cases.Comment: 4 pages, 2 figure
Scaling of Anisotropic Flows and Nuclear Equation of State in Intermediate Energy Heavy Ion Collisions
Elliptic flow () and hexadecupole flow () of light clusters have
been studied in details for 25 MeV/nucleon Kr + Sn at large
impact parameters by Quantum Molecular Dynamics model with different potential
parameters. Four parameter sets which include soft or hard equation of state
(EOS) with/without symmetry energy term are used. Both number-of-nucleon ()
scaling of the elliptic flow versus transverse momentum () and the scaling
of versus have been demonstrated for the light clusters
in all above calculation conditions. It was also found that the ratio of
keeps a constant of 1/2 which is independent of for all the
light fragments. By comparisons among different combinations of EOS and
symmetry potential term, the results show that the above scaling behaviors are
solid which do not depend the details of potential, while the strength of flows
is sensitive to EOS and symmetry potential term.Comment: 5 pages, 5 figure
Electronic specific heat and low energy quasiparticle excitations in superconducting state of single crystals
Low temperature specific heat has been measured and extensively analyzed on a
series of single crystals from underdoped to overdoped
regime. From these data the quasiparticle density of states (DOS) in the mixed
state is derived and compared to the predicted scaling law
of d-wave superconductivity. It is found that
the scaling law can be nicely followed by the optimally doped sample (x=0.15)
in quite wide region of (). However, the region
for this scaling becomes smaller and smaller towards more underdoped region: a
clear trend can be seen for samples from x=0.15 to 0.069. Therefore, generally
speaking, the scaling quality becomes worse on the underdoped samples in terms
of scalable region of . This feature in the underdoped region is
explained as due to the low energy excitations from a second order (for
example, anti-ferromagnetic correlation, d-density wave, spin density wave or
charge density wave order) that may co-exist or compete with superconductivity.
Surprisingly, deviations from the d-wave scaling law have also been found for
the overdoped sample (x=0.22). While the scaling law is reconciled for the
overdoped sample when the core size effect is taken into account. An important
discovery of present work is that the zero-temperature data follow the
Volovik's relation quite well for all samples
investigated here although the applicability of the d-wave scaling law to the
data at finite temperatures varies with doped hole concentration. Finally we
present the doping dependence of some parameters, such as, the residual linear
term , the value, etc. ...Comment: 15 pages, 24 figure
Reproducibility of image-based computational models of intracranial aneurysm; methodological issue
Genetic Vaccination-Induced Immune Responses to the Human Immunodeficiency Virus Protein Rev: Emergence of the Interleukin 2-Producing Helper T Lymphocyte
Overview summary The immune system poses a major obstacle to the long-term success of in vivo gene therapies. Immune responses to foreign transgene products and/or the vectors that facilitate gene transfer may neutralize the transgene product, eliminate transfected cells, and culminate in inflammation within transfected tissues. The majority of studies that address these issues have focused on cytotoxic T lymphocyte (CTL) and antibody responses induced by gene transfer. However, the IL-2-producing helper T lymphocyte (HTL) represents a critical regulatory cell that likely influences the inductive phase of the immune response following gene transfer. The current study employed limiting dilution analysis (LDA) techniques to characterize the development of IL-2-producing HTLs induced by genetic vaccination with a plasmid encoding the mutated HIV protein Rev M10. Further, we assessed the ability to inhibit the transgene-induced HTL response by cotransfer of a plasmid encoding the immunosuppressive cytokine TGFβ1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63282/1/hum.1998.9.15-2187.pd
Interference between the halves of a double-well trap containing a Bose-Einstein condensate
Interference between the halves of a double-well trap containing a
Bose-Einstein condensate is studied. It is found that when the atoms in the two
wells are initially in the coherent state, the intensity exhibits collapses and
revivals, but it does not for the initial Fock states. Whether the initial
states are in the coherent states or in a Fock states, the fidelity time has
nothing to do with collision. We point out that interference and its fidelity
can be adjusted experimentally by properly preparing the number and initial
states of the system.Comment: 10 pages, 3 figures, accepted by Phy. rev.
Non-invasive MR imaging of inflammation in a patient with both asymptomatic carotid atheroma and an abdominal aortic aneurysm: a case report.
Inflammation is a recognized risk factor for the vulnerable atherosclerotic plaque. USPIO-enhanced MRI imaging is a promising non-invasive method to identify high-risk atheromatous plaque inflammation in vivo in humans, in which areas of focal signal loss on MR images have been shown to correspond to the location of activated macrophages, typically at the shoulder regions of the plaque. This is the first report in humans describing simultaneous USPIO uptake within atheroma in two different arterial territories and again emphasises that atherosclerosis is a truly systemic disease. With further work, USPIO-enhanced MR imaging may be useful in identifying inflamed vulnerable atheromatous plaques in vivo, so refining patient selection for intervention and allowing appropriate early aggressive pharmacotherapy to prevent plaque rupture.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Ultrafast geometric manipulation of electron spin and detection of the geometric phase via Faraday rotation spectroscopy
Time-resolved Faraday rotation spectroscopy is currently exploited as a
powerful technique to probe spin dynamics in semiconductors. We propose here an
all-optical approach to geometrically manipulate electron spin and to detect
the geometric phase by this type of extremely sensitive experiment. The global
nature of the geometric phase can make the quantum manipulation more stable,
which may find interesting application in quantum devices.Comment: 4 pages, 3 figures, to appear in Phys. Rev.
HCV-induced miR146a Controls SOCS1/STAT3 and Cytokine Expression in Monocytes to Promote Regulatory T-cell Development
Host innate and adaptive immune responses must be tightly regulated by an intricate balance between positive and negative signals to ensure their appropriate onset and termination while fighting pathogens and avoiding autoimmunity; persistent pathogens may usurp these regulatory machineries to dampen host immune responses for their persistence in vivo. Here, we demonstrate that miR146a is up‐regulated in monocytes from hepatitis C virus (HCV )‐infected individuals compared to control subjects. Interestingly, miR146a expression in monocytes without HCV infection increased, whereas its level in monocytes with HCV infection decreased, following Toll‐like receptor (TLR ) stimulation. This miR146a induction by HCV infection and differential response to TLR stimulation were recapitulated in vitro in monocytes co‐cultured with hepatocytes with or without HCV infection. Importantly, inhibition of miR146a in monocytes from HCV ‐infected patients led to a decrease in IL ‐23, IL ‐10 and TGF ‐β expressions through the induction of suppressor of cytokine signalling 1 (SOCS 1) and the inhibition of signal transducer and activator transcription 3 (STAT 3), and this subsequently resulted in a decrease in regulatory T cells (Tregs) accumulated during HCV infection. These results suggest that miR146a may regulate SOCS 1/STAT 3 and cytokine signalling in monocytes, directing T‐cell differentiation and balancing immune clearance and immune injury during chronic viral infection
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