2,501 research outputs found
A Novel Ocular Drug Delivery System of Dexamethasone Sodium Phosphate for Noninfectious Uveitis Treatment
Treatment of anterior uveitis commonly requires 6â8 times daily administration of eye drops, which often leads to poor patient compliance. The treatment of intermediate and posterior uveitis is restricted to either oral medications with significant systemic side effects or local invasive methods, which are more expensive and associated with the development of ocular complications. There is an unmet need for a new drug delivery system that addresses these challenges. DSP-Visulex is a noninvasive drug delivery system that administers dexamethasone sodium phosphate by passive diffusion through the limbal sclera into the interior of the eye utilizing the transscleral pathway. Once-a-week administration of DSP-Visulex treatment regimens (i.e., 1â5 doses per month) has shown to be safe and efficacious for noninfectious uveitis in animal models including anterior uveitis, posterior uveitis, and/or panuveitis. In a clinical study of anterior uveitis, the DSP-Visulex treatments also have been shown to be safe and well tolerated and their efficacy (administered on days 1, 3, 8, and 15 with an optional treatment on Day 22) was comparable to that of the daily prednisolone acetate drops
Radiation from a moving Scalar Source
We study classical radiation and quantum bremsstrahlung effect of a moving
point scalar source. Our classical analysis provides another example of
resolving a well-known apparent paradox, that of whether a constantly
accelerating source radiates or not. Quantum mechanically, we show that for a
scalar source with arbitrary motion, the tree level emission rate of scalar
particles in the inertial frame equals the sum of emission and absorption rates
of zero-energy Rindler particles in the Rindler frame. We then explicitly
verify this result for a source undergoing constant proper acceleration.Comment: 15 pages, CU-TP-59
Decay of the free-theory vacuum of scalar field theory in de Sitter spacetime in the interaction picture
A free-theory vacuum state of an interacting field theory, e.g. quantum
gravity, is unstable at tree level in general due to spontaneous emission of
Fock-space particles in any spacetime with no global timelike Killing vectors,
such as de Sitter spacetime, in the interaction picture. As an example, the
rate of spontaneous emission of Fock-space particles is calculated in phi^4
theory in de Sitter spacetime. It is possible that this apparent spontaneous
emission does not correspond to any physical processes because the states are
not evolved by the true Hamiltonian in the interaction picture. Nevertheless,
the constant spontaneous emission of Fock-space particles in the interaction
picture clearly demonstrates that the in- and out-vacuum states are orthogonal
to each other as emphasized by Polyakov and that the in-out perturbation
theory, which presupposes some overlap between these two vacuum states, is
inadequate. Other possible implications of apparent vacuum instability of this
kind in the interaction picture are also discussed.Comment: title changed, 7 page
Low-energy sector quantization of a massless scalar field outside a Reissner-Nordstrom black hole and static sources
We quantize the low-energy sector of a massless scalar field in the
Reissner-Nordstrom spacetime. This allows the analysis of processes involving
soft scalar particles occurring outside charged black holes. In particular, we
compute the response of a static scalar source interacting with Hawking
radiation using the Unruh (and the Hartle-Hawking) vacuum. This response is
compared with the one obtained when the source is uniformly accelerated in the
usual vacuum of the Minkowski spacetime with the same proper acceleration. We
show that both responses are in general different in opposition to the result
obtained when the Reissner-Nordstrom black hole is replaced by a Schwarzschild
one. The conceptual relevance of this result is commented.Comment: 12 pages (REVTEX), no figure
Arbitrary Choice of Basic Variables in Density Functional Theory. II. Illustrative Applications
Our recent theory (Ref. 1) enables us to choose arbitrary quantities as the
basic variables of the density functional theory. In this paper we apply it to
several cases. In the case where the occupation matrix of localized orbitals is
chosen as a basic variable, we can obtain the single-particle equation which is
equivalent to that of the LDA+U method. The theory also leads to the
Hartree-Fock-Kohn-Sham equation by letting the exchange energy be a basic
variable. Furthermore, if the quantity associated with the density of states
near the Fermi level is chosen as a basic variable, the resulting
single-particle equation includes the additional potential which could mainly
modify the energy-band structures near the Fermi level.Comment: 27 page
Giant dispersion of critical currents in superconductor with fractal clusters of a normal phase
The influence of fractal clusters of a normal phase on the dynamics of a
magnetic flux trapped in a percolative superconductor is considered. The
critical current distribution and the current-voltage characteristics of
fractal superconducting structures in the resistive state are obtained for an
arbitrary fractal dimension of the cluster boundaries. The range of fractal
dimensions, where the dispersion of critical currents becomes infinite, is
found. It is revealed that the fractality of clusters depresses of the electric
field caused by the magnetic flux motion thus increasing the critical current
value. It is expected that the maximum current-carrying capability of a
superconductor can be achieved in the region of giant dispersion of critical
currents.Comment: 7 pages with 3 figure
Interaction of Hawking radiation with static sources outside a Schwarzschild black hole
We show that the response rate of (i) a static source interacting with
Hawking radiation of massless scalar field in Schwarzschild spacetime (with the
Unruh vacuum) and that of (ii) a uniformly accelerated source with the same
proper acceleration in Minkowski spacetime (with the Minkowski vacuum) are
equal. We show that this equality will not hold if the Unruh vacuum is replaced
by the Hartle-Hawking vacuum. It is verified that the source responds to the
Hawking radiation near the horizon as if it were at rest in a thermal bath in
Minkowski spacetime with the same temperature. It is also verified that the
response rate in the Hartle-Hawking vacuum approaches that in Minkowski
spacetime with the same temperature far away from the black hole. Finally, we
compare our results with others in the literature.Comment: 18 pages (REVTEX
Lamb Shift of Unruh Detector Levels
We argue that the energy levels of an Unruh detector experience an effect
similar to the Lamb shift in Quantum Electrodynamics. As a consequence, the
spectrum of energy levels in a curved background is different from that in flat
space. As examples, we consider a detector in an expanding Universe and in
Rindler space, and for the latter case we suggest a new expression for the
local virtual energy density seen by an accelerated observer. In the
ultraviolet domain, that is when the space between the energy levels is larger
than the Hubble rate or the acceleration of the detector, the Lamb shift
quantitatively dominates over the thermal response rate.Comment: 20 page
Scalar radiation emitted from a source rotating around a black hole
We analyze the scalar radiation emitted from a source rotating around a
Schwarzschild black hole using the framework of quantum field theory at the
tree level. We show that for relativistic circular orbits the emitted power is
about 20% to 30% smaller than what would be obtained in Minkowski spacetime. We
also show that most of the emitted energy escapes to infinity. Our formalism
can readily be adapted to investigate similar processes.Comment: 19 pages (REVTEX), 5 figures, title slightly changed, extra
demonstration and minor improvements included. To appear in Class. Quant.
Gra
On Infrared Effects in de~Sitter Background
We have estimated higher order quantum gravity corrections to de~Sitter
spacetime. Our results suggest that, while the classical spacetime metric may
be distorted by the graviton self-interactions, the corrections are relatively
weaker than previously thought, possibly growing like a power rather than
exponentially in time.Comment: 17, UM-TH-94-11, (1 postscript fig. at end
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