642 research outputs found
On the Influence of Stochastic Moments in the Solution of the Neutron Point Kinetics Equation
On the Influence of Stochastic Moments in the Solution of the Neutron Point
Kinetics EquationComment: 12 pages, 2 figure
Neutron/proton ratio of nucleon emissions as a probe of neutron skin
The dependence between neutron-to-proton yield ratio () and neutron
skin thickness () in neutron-rich projectile induced reactions is
investigated within the framework of the Isospin-Dependent Quantum Molecular
Dynamics (IQMD) model. The density distribution of the Droplet model is
embedded in the initialization of the neutron and proton densities in the
present IQMD model. By adjusting the diffuseness parameter of neutron density
in the Droplet model for the projectile, the relationship between the neutron
skin thickness and the corresponding in the collisions is obtained.
The results show strong linear correlation between and
for neutron-rich Ca and Ni isotopes. It is suggested that may be used
as an experimental observable to extract for neutron-rich nuclei,
which is very significant to the study of the nuclear structure of exotic
nuclei and the equation of state (EOS) of asymmetric nuclear matter.Comment: 7 pages, 5 figures; accepted by Phys. Lett.
Superfluidity of a perfect quantum crystal
In recent years, experimental data were published which point to the
possibility of the existence of superfluidity in solid helium. To investigate
this phenomenon theoretically we employ a hierarchy of equations for reduced
density matrices which describes a quantum system that is in thermodynamic
equilibrium below the Bose-Einstein condensation point, the hierarchy being
obtained earlier by the author. It is shown that the hierarchy admits solutions
relevant to a perfect crystal (immobile) in which there is a frictionless flow
of atoms, which testifies to the possibility of superfluidity in ideal solids.
The solutions are studied with the help of the bifurcation method and some
their peculiarities are found out. Various physical aspects of the problem,
among them experimental ones, are discussed as well.Comment: 24 pages with 2 figures, version accepted for publication in
Eur.Phys.J.
Unitary relation between a harmonic oscillator of time-dependent frequency and a simple harmonic oscillator with and without an inverse-square potential
The unitary operator which transforms a harmonic oscillator system of
time-dependent frequency into that of a simple harmonic oscillator of different
time-scale is found, with and without an inverse-square potential. It is shown
that for both cases, this operator can be used in finding complete sets of wave
functions of a generalized harmonic oscillator system from the well-known sets
of the simple harmonic oscillator. Exact invariants of the time-dependent
systems can also be obtained from the constant Hamiltonians of unit mass and
frequency by making use of this unitary transformation. The geometric phases
for the wave functions of a generalized harmonic oscillator with an
inverse-square potential are given.Comment: Phys. Rev. A (Brief Report), in pres
A standardized method for plasma extracellular vesicle isolation and size distribution analysis
The following protocol describes our workflow for isolation and quantification of plasma extracellular vesicles (EVs). It requires limited sample volume so that the scientific value of specimens is maximized. These steps include isolation of vesicles by automated size exclusion chromatography and quantification by tunable resistive pulse sensing. This workflow optimizes reproducibility by minimizing variations in processing, handling, and storage of EVs. EVs have significant diagnostic and therapeutic potential, but clinical application is limited by disparate methods of data collection. This standardized protocol is scalable and ensures efficient recovery of physiologically intact EVs that may be used in a variety of downstream biochemical and functional analyses. Simultaneous measurement quantifies EV concentration and size distribution absolutely. Absolute quantification corrects for variations in EV number and size, offering a novel method of standardization in downstream applications
Defects and glassy dynamics in solid He-4: Perspectives and current status
We review the anomalous behavior of solid He-4 at low temperatures with
particular attention to the role of structural defects present in solid. The
discussion centers around the possible role of two level systems and structural
glassy components for inducing the observed anomalies. We propose that the
origin of glassy behavior is due to the dynamics of defects like dislocations
formed in He-4. Within the developed framework of glassy components in a solid,
we give a summary of the results and predictions for the effects that cover the
mechanical, thermodynamic, viscoelastic, and electro-elastic contributions of
the glassy response of solid He-4. Our proposed glass model for solid He-4 has
several implications: (1) The anomalous properties of He-4 can be accounted for
by allowing defects to freeze out at lowest temperatures. The dynamics of solid
He-4 is governed by glasslike (glassy) relaxation processes and the
distribution of relaxation times varies significantly between different
torsional oscillator, shear modulus, and dielectric function experiments. (2)
Any defect freeze-out will be accompanied by thermodynamic signatures
consistent with entropy contributions from defects. It follows that such
entropy contribution is much smaller than the required superfluid fraction, yet
it is sufficient to account for excess entropy at lowest temperatures. (3) We
predict a Cole-Cole type relation between the real and imaginary part of the
response functions for rotational and planar shear that is occurring due to the
dynamics of defects. Similar results apply for other response functions. (4)
Using the framework of glassy dynamics, we predict low-frequency yet to be
measured electro-elastic features in defect rich He-4 crystals. These
predictions allow one to directly test the ideas and very presence of glassy
contributions in He-4.Comment: 33 pages, 13 figure
108 AUROTHIOMALATE INHIBITS COX-2 EXPRESSION AND PGE2 PRODUCTION IN CHONDROCYTES BY INCREASING MKP-1 EXPRESSION AND DECREASING p38 AND JNK PHOSPHORYLATION
The very high occurrence of cardiovascular events presents a major public health issue, because treatment remains suboptimal. Lowering LDL cholesterol (LDL-C) with statins or ezetimibe in combination with a statin reduces major adverse cardiovascular events. The cardiovascular risk reduction in relation to the absolute LDL-C reduction is linear for most interventions without evidence of attenuation or increase in risk at low LDL-C levels. Opportunities for innovation in dyslipidaemia treatment should address the substantial risk of lipid-associated cardiovascular events among patients optimally treated per guidelines but who cannot achieve LDL-C goals and who could benefit from additional LDL-C-lowering therapy or experience side effects of statins. Fresh approaches are needed to identify promising drug targets early and develop them efficiently. The Cardiovascular Round Table of the European Society of Cardiology (ESC) convened a workshop to discuss new lipid-lowering strategies for cardiovascular risk reduction. Opportunities to improve treatment approaches and the efficient study of new therapies were explored. Circulating biomarkers may not be fully reliable proxy indicators of the relationship between treatment effect and clinical outcome. Mendelian randomization studies may better inform development strategies and refine treatment targets before Phase 3. Trials should match the drug to appropriate lipid and patient profile, and guidelines may move towards a precision-based approach to individual patient management. Stakeholder collaboration is needed to ensure continued innovation and better international coordination of both regulatory aspects and guidelines. It should be noted that risk may also be addressed through increased attention to other risk factors such as smoking, hypertension, overweight, and inactivity
Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV
We present the first measurement of directed flow () at RHIC. is
found to be consistent with zero at pseudorapidities from -1.2 to 1.2,
then rises to the level of a couple of percent over the range . The latter observation is similar to data from NA49 if the SPS rapidities
are shifted by the difference in beam rapidity between RHIC and SPS.
Back-to-back jets emitted out-of-plane are found to be suppressed more if
compared to those emitted in-plane, which is consistent with {\it jet
quenching}. Using the scalar product method, we systematically compared
azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow
from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure
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