607 research outputs found
Evaluation Of A New Silicone-Methane Polymer Contact Lens
A new gas permeable contact lens is produced using a solid silicone core and a plasma polymer surface. This surface is hydrophilic and impermeable to macromolecules. The surface characteristics of this lens were compared with the surface characteristics of available silicone contact lenses. We found that in contrast to our lens, the silicone contact lenses lost their hydrophilic surface with time. In addition, they are permeable to lipid dyes, eg, Sudan red. © 1983 Arch Ophthalmol All rights reserved
Plate-Assisted Intramedullary Nailing of Distal Tibia Fractures
The combination of plate and intramedullary nailing has been established as the treatment of proximal tibial fractures. Nevertheless, at the distal end of the tibia, the application of the plate-assisted intramedullary nailing is rarely applied as a therapeutic technique. The authors provide a technical note on the use of the reduction plating technique for nail insertion as the management of distal tibia fractures.
Keywords: Distal tibia fracture; open reduction internal fixation; percutaneous plating; plate-assisted reduction; intramedullary nail; nail plate combination
Dynamic structure factor of Luttinger liquids with quadratic energy dispersion and long-range interactions
We calculate the dynamic structure factor S (omega, q) of spinless fermions
in one dimension with quadratic energy dispersion k^2/2m and long range
density-density interaction whose Fourier transform f_q is dominated by small
momentum-transfers q << q_0 << k_F. Here q_0 is a momentum-transfer cutoff and
k_F is the Fermi momentum. Using functional bosonization and the known
properties of symmetrized closed fermion loops, we obtain an expansion of the
inverse irreducible polarization to second order in the small parameter q_0 /
k_F. In contrast to perturbation theory based on conventional bosonization, our
functional bosonization approach is not plagued by mass-shell singularities.
For interactions which can be expanded as f_q = f_0 + f_0^{2} q^2/2 + O (q^4)
with finite f_0^{2} we show that the momentum scale q_c = 1/ | m f_0^{2} |
separates two regimes characterized by a different q-dependence of the width
gamma_q of the collective zero sound mode and other features of S (omega, q).
For q_c << q << k_F we find that the line-shape in this regime is
non-Lorentzian with an overall width gamma_q of order q^3/(m q_c) and a
threshold singularity at the lower edge.Comment: 33 Revtex pages, 17 figure
What features make Pocket Beaches unique in Terms of Coastal Processes?
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Influence of Rotation on Pulsar Radiation Characteristics
We present a relativistic model for pulsar radio emission by including the
effect of rotation on coherent curvature radiation by bunches. We find that
rotation broadens the width of leading component compared to the width of
trailing component. We estimate the component widths in the average pulse
profiles of about 24 pulsars, and find that 19 of them have a broader leading
component. We explain this difference in the component widths by using the
nested cone emission geometry.
We estimate the effect of pulsar spin on the Stokes parameters, and find that
the inclination between the rotation and magnetic axes can introduce an
asymmetry in the circular polarization of the conal components. We analyze the
single pulse polarization data of PSR B0329+54 at 606 MHz, and find that in its
conal components, one sense of circular polarization dominates in the leading
component while the other sense dominates in the trailing component. Our
simulation shows that changing the sign of the impact parameter changes the
sense of circular polarization as well as the swing of polarization angle.Comment: 20 pages, 4 Postscript figures, uses aastex.cls. Accepted for
Publication in ApJ 200
Feedback Enhanced Phonon Lasing of a Microwave Frequency Resonator
The amplitude of self-oscillating mechanical resonators in cavity
optomechanical systems is typically limited by nonlinearities arising from the
cavity's finite optical bandwidth. We propose and demonstrate a feedback
technique for increasing this limit. By modulating the cavity input field with
a signal derived from its output intensity, we increase the amplitude of a
self-oscillating GHz frequency mechanical resonator by (increase in
coherent phonon number of ) limited only by the achievable optomechanical
cooperativity of the system. This technique will advance applications dependent
on high dynamic mechanical stress, such as coherent spin-phonon coupling, as
well as implementations of sensors based on self-oscillating resonators
CNS aspergillosis in a patient with Crohn’s disease on immunosuppressants: a case report
Fungal infections of the central nervous system are an uncommon cause of rapid decline in consciousness. We describe the case of central nervous system aspergillosis in a patient on immunosupressants whose clinical course highlights the need for an aggressive approach to diagnosis
Bridging inter-flow and intra-flow network coding in wireless mesh networks:From theory to implementation
Induced gamma activity in primary visual cortex is related to luminance and not color contrast: an MEG study
Gamma activity in the visual cortex has been reported in numerous EEG studies of coherent and illusory figures. A dominant theme of many such findings has been that temporal synchronization in the gamma band in response to these identifiable percepts is related to perceptual binding of the common features of the stimulus. In two recent studies using magnetoencephalography (MEG) and the beamformer analysis technique, we have shown that the magnitude of induced gamma activity in visual cortex is dependent upon independent stimulus features such as spatial frequency and contrast. In particular, we showed that induced gamma activity is maximal in response to gratings of 3 cycles per degree (3 cpd) of high luminance contrast. In this work, we set out to examine stimulus contrast further by using isoluminant red/green gratings that possess color but not luminance contrast using the same cohort of subjects. We found no induced gamma activity in V1 or visual cortex in response to the isoluminant gratings in these subjects who had previously shown strong induced gamma activity in V1 for luminance contrast gratings
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