5,895 research outputs found
Steady state sedimentation of ultrasoft colloids
The structural and dynamical properties of ultra-soft colloids - star
polymers - exposed to a uniform external force field are analyzed applying the
multiparticle collision dynamics approach, a hybrid coarse-grain mesoscale
simulation approach, which captures thermal fluctuations and long-range
hydrodynamic interactions. In the weak field limit, the structure of the star
polymer is nearly unchanged, however in an intermediate regime, the radius of
gyration decreases, in particular transverse to the sedimentation direction. In
the limit of a strong field, the radius of gyration increases with field
strength. Correspondingly, the sedimentation coefficient increases with
increasing field strength, passes through a maximum and decreases again at high
field strengths. The maximum value depends on the functionality of the star
polymer. High field strengths lead to symmetry breaking with trailing, strongly
stretched polymer arms and a compact star polymer body. In the weak field
linear response regime, the sedimentation coefficient follows the scaling
relation of a star polymer in terms of functionality and arm length
Computational coarse graining of a randomly forced 1-D Burgers equation
We explore a computational approach to coarse graining the evolution of the
large-scale features of a randomly forced Burgers equation in one spatial
dimension. The long term evolution of the solution energy spectrum appears
self-similar in time. We demonstrate coarse projective integration and coarse
dynamic renormalization as tools that accelerate the extraction of macroscopic
information (integration in time, self-similar shapes, and nontrivial dynamic
exponents) from short bursts of appropriately initialized direct simulation.
These procedures solve numerically an effective evolution equation for the
energy spectrum without ever deriving this equation in closed form.Comment: 21 pages, 7 figure
Lovelock black holes surrounded by quintessence
Lovelock gravity consisting of the dimensionally continued Euler densities is
a natural generalization of general relativity to higher dimensions such that
equations of motion are still second order, and the theory is free of ghosts. A
scalar field with a positive potential that yields an accelerating universe has
been termed quintessence. We present exact black hole solutions in
-dimensional Lovelock gravity surrounded by quintessence matter and also
perform a detailed thermodynamical study. Further, we find that the mass,
entropy, and temperature of the black hole are corrected due to the
quintessence background. In particular, we find that phase transition occurs
with divergence of heat capacity at the critical horizon radius, and that
specific heat becomes positive for allowing the black hole to become
thermodynamically stable.Comment: 15 pages, 3 figures, accepted for publication in EPJ
Sarcoma immunotherapy.
Much of our knowledge regarding cancer immunotherapy has been derived from sarcoma models. However, translation of preclinical findings to bedside success has been limited in this disease, though several intriguing clinical studies hint at the potential efficacy of this treatment modality. The rarity and heterogeneity of tumors of mesenchymal origin continues to be a challenge from a therapeutic standpoint. Nonetheless, sarcomas remain attractive targets for immunotherapy, as they can be characterized by specific epitopes, either from their mesenchymal origins or specific alterations in gene products. To date, standard vaccine trials have proven disappointing, likely due to mechanisms by which tumors equilibrate with and ultimately escape immune surveillance. More sophisticated approaches will likely require multimodal techniques, both by enhancing immunity, but also geared towards overcoming innate mechanisms of immunosuppression that favor tumorigenesis
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