8,122 research outputs found
Phase-sensitive quantum effects in Andreev conductance of the SNS system of metals with macroscopic phase breaking length
The dissipative component of electron transport through the doubly connected
SNS Andreev interferometer indium (S)-aluminium (N)-indium (S) has been
studied. Within helium temperature range, the conductance of the individual
sections of the interferometer exhibits phase-sensitive oscillations of
quantum-interference nature. In the non-domain (normal) state of indium
narrowing adjacent to NS interface, the nonresonance oscillations have been
observed, with the period inversely proportional to the area of the
interferometer orifice. In the domain intermediate state of the narrowing, the
magneto-temperature resistive oscillations appeared, with the period determined
by the coherence length in the magnetic field equal to the critical one. The
oscillating component of resonance form has been observed in the conductance of
the macroscopic N-aluminium part of the system. The phase of the oscillations
appears to be shifted by compared to that of nonresonance oscillations.
We offer an explanation in terms of the contribution into Josephson current
from the coherent quasiparticles with energies of order of the Thouless energy.
The behavior of dissipative transport with temperature has been studied in a
clean normal metal in the vicinity of a single point NS contact.Comment: 9 pages, 7 figures, to be published in Low Temp. Phys., v. 29, No.
12, 200
Unilateral cleft lip repair: Technical maneuvers to achieve vermilion and mucosal height
Patients with unilateral cleft lip often require secondary procedures due to asymmetric fullness or deficiencies along the mucosal free margin of the upper lip. Here, we describe our technique for mucosal advancement and repair to attain symmetry.
Methods: Maneuvers to obtain vermilion and mucosal height include (1) use of a tailored vermilion flap; (2) supraperiosteal release of the lesser segment; (3) backcut poker incision to mobilize the mucosal flap on the lesser segment; (4) transverse release of mucosa across the greater segment; (5) accurate reduction along vermilion-mucosal junction; and (6) bilateral medial mucosal advancement. To examine postoperative outcomes, photographic data were available for 14 patients with unilateral complete cleft lip. The Cleft Lip Component Symmetry Index was then calculated as a ratio of upper lip height on cleft to noncleft sides, where an index of 1 indicates symmetry.
Results: Sixteen consecutive patients underwent unilateral cleft lip repair with this technique over a 3-year period, none of whom have required secondary operations. The symmetry index for 14 of 16 patients was 1.02 ± 0.11 (95% confidence interval [0.96, 1.08],
Conclusions: Postoperative asymmetry after unilateral cleft lip repair, particularly along the free margin, continues to be a common problem, necessitating secondary procedures. The technique of mucosal repair merits more careful attention than it has previously received, and here we describe in detail a method that has allowed for improved symmetry
On the Antenna Beam Shape Reconstruction Using Planet Transit
The calibration of the in-flight antenna beam shape and possible
beamdegradation is one of the most crucial tasks for the upcoming Planck
mission. We examine several effects which could significantly influence the
in-flight main beam calibration using planet transit: the problems of the
variability of the Jupiter's flux, the antenna temperature and passing of the
planets through the main beam. We estimate these effects on the antenna beam
shape calibration and calculate the limits on the main beam and far sidelobe
measurements, using observations of Jupiter and Saturn. We also discuss
possible effects of degradation of the mirror surfaces and specify
corresponding parameters which can help us to determine these effects.Comment: 10 pages, 8 figure
Damping in 2D and 3D dilute Bose gases
Damping in 2D and 3D dilute gases is investigated using both the
hydrodynamical approach and the Hartree-Fock-Bogoliubov (HFB) approximation .
We found that the both methods are good for the Beliaev damping at zero
temperature and Landau damping at very low temperature, however, at high
temperature, the hydrodynamical approach overestimates the Landau damping and
the HFB gives a better approximation. This result shows that the comparison of
the theoretical calculation using the hydrodynamical approach and the
experimental data for high temperature done by Vincent Liu (PRL {\bf21} 4056
(1997)) is not proper. For two-dimensional systems, we show that the Beliaev
damping rate is proportional to and the Landau damping rate is
proportional to for low temperature and to for high temperature. We
also show that in two dimensions the hydrodynamical approach gives the same
result for zero temperature and for low temperature as HFB, but overestimates
the Landau damping for high temperature.Comment: 11 pages, 4 figure
MONKEY: identifying conserved transcription-factor binding sites in multiple alignments using a binding site-specific evolutionary model
We introduce a method (MONKEY) to identify conserved transcription-factor binding sites in multispecies alignments. MONKEY employs probabilistic models of factor specificity and binding-site evolution, on which basis we compute the likelihood that putative sites are conserved and assign statistical significance to each hit. Using genomes from the genus Saccharomyces, we illustrate how the significance of real sites increases with evolutionary distance and explore the relationship between conservation and function
Ac transport studies in polymers by a resistor network and transfer matrix approaches: application to polyaniline
A statistical model of resistor network is proposed to describe a polymer
structure and to simulate the real and imaginary components of its ac
resistivity. It takes into account the polydispersiveness of the material as
well as intrachain and interchain charge transport processes. By the
application of a transfer matrix technique, it reproduces ac resistivity
measurements carried out with polyaniline films in different doping degrees and
at different temperatures. Our results indicate that interchain processes
govern the resistivity behavior in the low frequency region while, for higher
frequencies, intrachain mechanisms are dominant.Comment: LaTeX file, 15 pages, 5 ps figures, to appear in Phys. Rev.
Investigating weekend effect in the management of upper and lower extremity degloving injuries
BACKGROUND: Weekend presentation has been associated with adverse outcomes in emergent conditions, including stroke, myocardial infarction, and critical limb ischemia. We examine whether a weekend effect exists in the management of and outcomes after extremity degloving injuries.
METHODS: The cohort included adults presenting with open extremity degloving injuries to a tertiary level one trauma center between June 2018 and May 2022. We collected demographics, comorbidities, injury information, interventions, and complications. Propensity score weighting was used to minimize confounding differences between those presenting on weekends (Sat-Sun) versus weekdays (Mon-Fri). Weighted regressions were used to examine differences in interventions by day of presentation. Multivariable weighted regressions accounting for differences in interventions received were used to examine whether weekend presentation was associated with amputation risk, complications, or functional deficits.
RESULTS: Ninety-five patients with 100 open extremity degloving injuries were included. In total, 39% of injuries were weekend-presenting. There was a higher rate of noninsulin-dependent diabetes among patients presenting on weekends (
CONCLUSION: Weekend presentation may impact interventions received and amputation risk in patients presenting with open extremity degloving injuries
Capacitive Spring Softening in Single-Walled Carbon Nanotube Nanoelectromechanical Resonators
We report the capacitive spring softening effect observed in single-walled
carbon nanotube (SWNT) nanoelectromechanical (NEM) resonators. The nanotube
resonators adopt dual-gate configuration with both bottom-gate and side-gate
capable of tuning the resonance frequency through capacitive coupling.
Interestingly, downward resonance frequency shifting is observed with
increasing side-gate voltage, which can be attributed to the capacitive
softening of spring constant. Furthermore, in-plane vibrational modes exhibit
much stronger spring softening effect than out-of-plan modes. Our dual-gate
design should enable the differentiation between these two types of vibrational
modes, and open up new possibility for nonlinear operation of nanotube
resonators.Comment: 12 pages/ 3 figure
Interleukin-13 Genetic Variants, Household Carpet Use and Childhood Asthma
10.1371/journal.pone.0051970PLoS ONE81
- …