8,132 research outputs found
On the adhesion of particles to a cell layer under flow
The non-specific adhesion of spherical particles to a cell substrate is
analyzed in a parallel plate flow chamber, addressing the effect of the
particle size. Differently from other experiments, the total volume of the
injected particles has been fixed, rather than the total number of particles,
as the diameter d of the particles is changed from 500 nm up to 10 m. From
the analysis of the experimental data, simple and instructive scaling adhesion
laws have been derived showing that (i) the number of particles adherent to the
cell layer per unit surface decreases with the size of the particle as d^(-1.7)
; and consequently (ii) the volume of the particles adherent per unit surface
increases with the size of the particles as d^(+1.3). These results are of
importance in the "rational design" of nanoparticles for drug delivery and
biomedical imaging.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Fermionic Corrections to Fluid Dynamics from BTZ Black Hole
We reconstruct the complete fermionic orbit of the non-extremal BTZ black
hole by acting with finite supersymmetry transformations. The solution
satisfies the exact supergravity equations of motion to all orders in the
fermonic expansion and the final result is given in terms of fermionic
bilinears. By fluid/gravity correspondence, we derive linearized Navier-Stokes
equations and a set of new differential equations from Rarita-Schwinger
equation. We compute the boundary energy-momentum tensor and we interpret the
result as a perfect fluid with a modified definition of fluid velocity.
Finally, we derive the modified expression for the entropy of the black hole in
terms of the fermionic bilinears.Comment: 21 pages, Latex2e, no figure
Fermionic Wigs for BTZ Black Holes
We compute the wig for the BTZ black hole, namely the complete non-linear
solution of supergravity equations with all fermionic zero modes. We use a
"gauge completion" method starting from AdS_3 Killing spinors to generate the
gravitinos fields associated to the BH and we compute the back-reaction on the
metric. Due to the anticommutative properties of the fermionic hairs the
resummation of these effects truncates at some order. We illustrate the
technique proposed in a precedent paper in a very explicit and analytical form.
We also compute the mass, the angular momentum and other charges with their
corrections.Comment: 11 pages, no figure
Fermions, Wigs, and Attractors
We compute the modifications to the attractor mechanism due to fermionic
corrections. In N=2, D=4 supergravity, at the fourth order, we find a new
contribution to the horizon values of the scalar fields of the vector
multiplets.Comment: v2 : 1+11 pages; paper reorganized in Sections; Sec. 5 added, with
detailed treatment of the axion-dilaton model; some typos fixed and
references adde
Control of magnetism in singlet-triplet superconducting heterostructures
We analyze the magnetization at the interface between singlet and triplet
superconductors and show that its direction and dependence on the phase
difference across the junction are strongly tied to the structure of the
triplet order parameter as well as to the pairing interactions. We consider
equal spin helical, opposite spin chiral, and mixed symmetry pairing on the
triplet side and show that the magnetization vanishes at only in the
first case, follows approximately a behavior for the second, and
shows higher harmonics for the last configuration. We trace the origin of the
magnetization to the magnetic structure of the Andreev bound states near the
interface, and provide a symmetry-based explanation of the results. Our
findings can be used to control the magnetization in superconducting
heterostructures and to test symmetries of spin-triplet superconductors.Comment: 5 pages, 3 figure
The Universal Rotation Curve of Spiral Galaxies. II The Dark Matter Distribution out to the Virial Radius
In the current LambdaCDM cosmological scenario, N-body simulations provide us
with a Universal mass profile, and consequently a Universal equilibrium
circular velocity of the virialized objects, as galaxies. In this paper we
obtain, by combining kinematical data of their inner regions with global
observational properties, the Universal Rotation Curve (URC) of disk galaxies
and the corresponding mass distribution out to their virial radius. This curve
extends the results of Paper I, concerning the inner luminous regions of Sb-Im
spirals, out to the edge of the galaxy halos.Comment: In press on MNRAS. 10 pages, 8 figures. The Mathematica code for the
figures is available at: http://www.novicosmo.org/salucci.asp Corrected typo
Fermionic Wigs for AdS-Schwarzschild Black Holes
We provide the metric, the gravitino fields and the gauge fields to all
orders in the fermionic zero modes for D=5 and D=4, N=2 gauged supergravity
solutions starting from non-extremal AdS--Schwarzschild black holes. We compute
the Brown-York stress--energy tensor on the boundary of AdS_5 / AdS_4 spaces
and we discuss some implications of the fermionic corrections to perfect fluid
interpretation of the boundary theory. The complete non-linear solution, which
we denote as fermionic wig, is achieved by acting with supersymmetry
transformations upon the supergravity fields and that expansion naturally
truncates at some order in the fermionic zero modes.Comment: 27 pages, Latex2e, no figures, 3 ancillary file
On surfaces with pg = 2, q = 1 and K2 = 5
We consider minimal surfaces of general type with pg = 2, q = 1 and K2 = 5. We provide a stratification of the corresponding moduli space M and we give some bounds for the number and the dimensions of its irreducible components. © Springer-Verlag 2011
Fluctuation relation for a L\'evy particle
We study the work fluctuations of a particle subjected to a deterministic
drag force plus a random forcing whose statistics is of the L\'evy type. In the
stationary regime, the probability density of the work is found to have ``fat''
power-law tails which assign a relatively high probability to large
fluctuations compared with the case where the random forcing is Gaussian. These
tails lead to a strong violation of existing fluctuation theorems, as the ratio
of the probabilities of positive and negative work fluctuations of equal
magnitude behaves in a non-monotonic way. Possible experiments that could probe
these features are proposed.Comment: 5 pages, 2 figures, RevTeX4; v2: minor corrections and references
added; v3: typos corrected, new conclusion, close to published versio
Microbiota–Liver Diseases Interactions
: Gut microbiota regulates essential processes of host metabolism and physiology: synthesis of vitamins, digestion of foods non-digestible by the host (such as fibers), and-most important-protects the digestive tract from pathogens. In this study, we focus on the CRISPR/Cas9 technology, which is extensively used to correct multiple diseases, including liver diseases. Then, we discuss the non-alcoholic fatty liver disease (NAFLD), affecting more than 25% of the global population; colorectal cancer (CRC) is second in mortality. We give space to rarely discussed topics, such as pathobionts and multiple mutations. Pathobionts help to understand the origin and complexity of the microbiota. Since several types of cancers have as target the gut, it is vital extending the research of multiple mutations to the type of cancers affecting the gut-liver axis
- …