466 research outputs found
Alteration of early dendritic cell activation by cancer cell lines predisposes immunosuppression, which cannot be reversed by TLR4 stimulation
Dendritic cells (DCs) have shown promise for use in cancer vaccine and cancer immunotherapy studies. However, we demonstrate that cancer cell lines can negatively interfere with DC generation in granulocyte-macrophage colony-stimulating factor (GM-CSF)-derived cultures, although cancer cells are able to enhance CD80 cell surface activation marker and cytokine secretion. Furthermore, in the presence of cancer cells, GM-CSF-derived DCs are unable to stimulate T-cells. Additional stimulation with toll-like receptor 4 cannot fully reverse the suppressive effect of cancer cells or supernatant. Hence, it is imperative to understand the immunosuppressive effects of cancer on DCs in order for DC-based cancer immunotherapy to be successful
Weyl-Underhill-Emmrich quantization and the Stratonovich-Weyl quantizer
Weyl-Underhill-Emmrich (WUE) quantization and its generalization are
considered. It is shown that an axiomatic definition of the Stratonovich-Weyl
(SW) quantizer leads to severe difficulties. Quantization on the cylinder
within the WUE formalism is discussed.Comment: 15+1 pages, no figure
Charged Rotating Black Holes in Four-Dimensional Gauged and Ungauged Supergravities
We study four-dimensional non-extremal charged rotating black holes in
ungauged and gauged supergravity. In the ungauged case, we obtain rotating
black holes with four independent charges, as solutions of N=2 supergravity
coupled to three abelian vector multiplets. This is done by reducing the theory
along the time direction to three dimensions, where it has an O(4,4) global
symmetry. Applied to the reduction of the uncharged Kerr metric,
O(1,1)^4\subset O(4,4) transformations generate new solutions that correspond,
after lifting back to four dimensions, to the introduction of four independent
electromagnetic charges. In the case where these charges are set pairwise
equal, we then generalise the four-dimensional rotating black holes to
solutions of gauged N=4 supergravity, with mass, angular momentum and two
independent electromagnetic charges. The dilaton and axion fields are
non-constant. We also find generalisations of the gauged and ungauged solutions
to include the NUT parameter, and for the ungauged solutions, the acceleration
parameter too. The solutions in gauged supergravity provide new gravitational
backgrounds for a further study of the AdS_4/CFT_3 correspondence at non-zero
temperature.Comment: Latex, 30 page
Pair Production of Topological anti de Sitter Black Holes
The pair creation of black holes with event horizons of non-trivial topology
is described. The spacetimes are all limiting cases of the cosmological
metric. They are generalizations of the dimensional black hole and have
asymptotically anti de Sitter behaviour. Domain walls instantons can mediate
their pair creation for a wide range of mass and charge.Comment: 4 pages, uses late
Testing Born-Infeld electrodynamics in waveguides
Waveguides can be employed to test non-linear effects in electrodynamics. We
solve Born-Infeld equations for TE waves in a rectangular waveguide. We show
that the energy velocity acquires a dependence on the amplitude, and harmonic
components appear as a consequence of the non-linear behavior.Comment: 3 pages. To appear in PR
Charged Particles and the Electro-Magnetic Field in Non-Inertial Frames of Minkowski Spacetime: II. Applications: Rotating Frames, Sagnac Effect, Faraday Rotation, Wrap-up Effect
We apply the theory of non-inertial frames in Minkowski space-time, developed
in the previous paper, to various relevant physical systems. We give the 3+1
description without coordinate-singularities of the rotating disk and the
Sagnac effect, with added comments on pulsar magnetosphere and on a
relativistic extension of the Earth-fixed coordinate system. Then we study
properties of Maxwell equations in non-inertial frames like the wrap-up effect
and the Faraday rotation in astrophysics.Comment: This paper and the second one are an adaptation of arXiv 0812.3057
for publication on Int.J.Geom. Methods in Modern Phys. 36
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