355 research outputs found
Kinetics of binding and geometry of cells on molecular biochips
We examine how the shape of cells and the geometry of experiment affect the
reaction-diffusion kinetics at the binding between target and probe molecules
on molecular biochips. In particular, we compare the binding kinetics for the
probes immobilized on surface of the semispherical and flat circular cells, the
limit of thin slab of analyte solution over probe cell as well as hemispherical
gel pads and cells printed in gel slab over a substrate. It is shown that
hemispherical geometry provides significantly faster binding kinetics and
ensures more spatially homogeneous distribution of local (from a pixel) signals
over a cell in the transient regime. The advantage of using thin slabs with
small volume of analyte solution may be hampered by the much longer binding
kinetics needing the auxiliary mixing devices. Our analysis proves that the
shape of cells and the geometry of experiment should be included to the list of
essential factors at biochip designing.Comment: 10 pages, 1 figur
Antimatter Bounds by Anti-Asteroids annihilations on Planets and Sun
The existence of antimatter stars in the Galaxy as possible signature for
inflationary models with non-homogeneous baryo-synthesis may leave the trace by
antimatter cosmic rays as well as by their secondaries (anti-planets and
anti-meteorites) diffused bodies in our galactic halo. The anti-meteorite flux
may leave its explosive gamma signature by colliding on lunar soil as well as
on terrestrial, jovian and solar atmospheres. However the propagation in galaxy
and the consequent evaporation in galactic matter gas suppress the lightest (m
< 10^(-2)g) anti-meteorites. Anisotropic annihilation of larger anti-meteorites
within a narrow mass window, maybe rarely deflected, bounced by the galactic
gas disk, escaping detection in our solar system. Nevertheless heaviest
anti-meteorites (m > 10^(-1)g up to 10^(6)g) are unable to be deflected by the
thin galactic gas surface annihilation; they might hit the Sun (or rarely
Jupiter) leading to an explosive gamma event and a spectacular track with a
bouncing and even a propelling annihilation on cromosphere and photosphere.
Their anti-nuclei annihilation in pions and their final hard gammas showering
may be observabe as a "solar flare" at a rate nearly comparable to the observed
ones. From their absence we may infer bounds on antimatter-matter ratio near or
below 10^(-9) limit: already recorded data in BATSE catalog might be applied.Comment: 6 pages, more accurate estimate and minor correction
Physical Origin, Evolution and Observational Signature of Diffused Antiworld
The existence of macroscopic regions with antibaryon excess in the baryon
asymmetric Universe with general baryon excess is the possible consequence of
practically all models of baryosynthesis. Diffusion of matter and antimatter to
the border of antimatter domains defines the minimal scale of the antimatter
domains surviving to the present time. A model of diffused antiworld is
considered, in which the density within the surviving antimatter domains is too
low to form gravitationally bound objects. The possibility to test this model
by measurements of cosmic gamma ray fluxes is discussed. The expected gamma ray
flux is found to be acceptable for modern cosmic gamma ray detectors and for
those planned for the near future.Comment: 9 page
Spontaneous mass current and textures of p-wave superfluids of trapped Fermionic atom gases at rest and under rotation
It is found theoretically based on the Ginzburg-Landau framework that p-wave
superfluids of neutral atom gases in three dimension harmonic traps exhibit
spontaneous mass current at rest, whose direction depends on trap geometry.
Under rotation various types of the order parameter textures are stabilized,
including Mermin-Ho and Anderson-Toulouse-Chechetkin vortices. In a cigar shape
trap spontaneous current flows longitudial to the rotation axis and thus
perpendicular to the ordinary rotational current. These features, spontaneous
mass current at rest and texture formation, can be used as diagnoses for p-wave
superfluidity.Comment: 5 pages, 5 figure
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