981 research outputs found
A case series of percutaneous tension band wiring technique for fixation of fractures of olecranon and patella
There are several advantages in the treatment of fractures by means of closed reduction. Percutaneous fixation is a type of biological fixation. The aim and objectives of this study are to demonstrate the technique of percutaneous tension band wiring in cases of transverse, non- comminuted olecranon and patella fractures and to decrease the soft tissue dissection, blood loss, chances of infection and to ensure speedy mobilization using the innovative percutaneous fixation technique. This retrospective study includes ten patients of olecranon and ten patients of patella operated by the same surgeon. All patients were operated with percutaneous tension band wiring for olecranon and patella. There were six males and four females with olecranon fractures. There were seven males and three females who suffered patella fractures. The average duration of surgery was 55 minutes and average follow up was 24±6 weeks. The suture removal was done at 2 weeks. All patients had full range of movements at six weeks with significantly improved DASH score and Oxford knee score. None of the patients had any complications. Percutaneous fixation decreases the chances of bleeding secondary to unnecessary soft tissue dissection, thereby decreasing the post-operative morbidity. It also, convincingly, decreases the chances of post-operative infection and promotes early mobilization. Closed reduction with percutaneous fixation is believed to be an innovative, safe, reliable and efficient method of managing these difficult fractures
Transport methods and interactions for space radiations
A review of the program in space radiation protection at the Langley Research Center is given. The relevant Boltzmann equations are given with a discussion of approximation procedures for space applications. The interaction coefficients are related to solution of the many-body Schroedinger equation with nuclear and electromagnetic forces. Various solution techniques are discussed to obtain relevant interaction cross sections with extensive comparison with experiments. Solution techniques for the Boltzmann equations are discussed in detail. Transport computer code validation is discussed through analytical benchmarking, comparison with other codes, comparison with laboratory experiments and measurements in space. Applications to lunar and Mars missions are discussed
Cytotoxic Effect of Poly-Dispersed Single Walled Carbon Nanotubes on Erythrocytes In Vitro and In Vivo
Single wall Carbon Nanotubes (SWCNTs) are hydrophobic and do not disperse in aqueous solvents. Acid functionalization of SWCNTs results in attachment of carboxy and sulfonate groups to carbon atoms and the resulting acid functionalized product (AF-SWCNTs) is negatively charged and disperses easily in water and buffers. In the present study, effect of AF-SWCNTs on blood erythrocytes was examined. Incubation of mouse erythrocytes with AF-SWCNTs and not with control SWCNTs, resulted in a dose and time dependent lysis of erythrocyte. Using fluorescence tagged AF-SWCNTs, binding of AF-SWCNTs with erythrocytes could be demonstrated. Confocal microscopy results indicated that AF-SWCNTs could enter the erythrocytes. Treatment with AF-SWCNTs resulted in exposure of hydrophobic patches on erythrocyte membrane that is indicative of membrane damage. A time and dose dependent increase in externalization of phosphatidylserine on erythrocyte membrane bilayer was also found. Administration of AF-SWCNTs through intravenous route resulted in a transient anemia as seen by a sharp decline in blood erythrocyte count accompanied with a significant drop in blood haemoglobin level. Administration of AF-SWCNTs through intratracheal administration also showed significant decline in RBC count while administration through other routes (gavage and intra-peritoneal) was not effective. By using a recently developed technique of a two step in vivo biotinylation of erythrocytes that enables simultaneous enumeration of young (age <10 days) and old (age>40 days) erythrocytes in mouse blood, it was found that the in vivo toxic effect of AF-SWCNTs was more pronounced on older subpopulation of erythrocytes. Subpopulation of old erythrocytes fell after treatment with AF-SWCNTs but recovered by third day after the intravenous administration of AF-SWCNTs. Taken together our results indicate that treatment with AF-SWCNTs results in acute membrane damage and eventual lysis of erythrocytes. Intravenous administration of AF-SWCNTs resulted in a transient anemia in which older erythrocytes are preferably lysed
Spectroscopic Evidence for the Localization of Skyrmions near Nu=1 as T->0
Optically pumped nuclear magnetic resonance measurements of Ga-71 spectra
were carried out in an n-doped GaAs/Al0.1Ga0.9As multiple quantum well sample
near the integer quantum Hall ground state Nu=1. As the temperature is lowered
(down to T~0.3 K), a ``tilted plateau'' emerges in the Knight shift data, which
is a novel experimental signature of quasiparticle localization. The dependence
of the spectra on both T and Nu suggests that the localization is a collective
process. The frozen limit spectra appear to rule out a 2D lattice of
conventional skyrmions.Comment: 4 pages (REVTEX), 5 eps figures embedded in text, published versio
Toolbox for Discovering Dynamic System Relations via TAG Guided Genetic Programming
Data-driven modeling of nonlinear dynamical systems often require an expert
user to take critical decisions a priori to the identification procedure.
Recently an automated strategy for data driven modeling of \textit{single-input
single-output} (SISO) nonlinear dynamical systems based on \textit{Genetic
Programming} (GP) and \textit{Tree Adjoining Grammars} (TAG) has been
introduced. The current paper extends these latest findings by proposing a
\textit{multi-input multi-output} (MIMO) TAG modeling framework for polynomial
NARMAX models. Moreover we introduce a TAG identification toolbox in Matlab
that provides implementation of the proposed methodology to solve multi-input
multi-output identification problems under NARMAX noise assumption. The
capabilities of the toolbox and the modelling methodology are demonstrated in
the identification of two SISO and one MIMO nonlinear dynamical benchmark
models
Observation of a new phase transition between fully and partially polarized quantum Hall states with charge and spin gaps at
The average electron spin-polarization of two-dimensional electron
gas confined in multiple quantum-wells was measured by
nuclear magnetic resonance (NMR) near the fractional quantum Hall state with
filling factor . Above this filling factor (), a strong depolarization is observed corresponding to two spin flips per
additional flux quantum. The most remarkable behavior of the polarization is
observed at , where a quantum phase transition from a partially
polarized () to a fully polarized ()
state can be driven by increasing the ratio between the Zeeman and the Coulomb
energy above a critical value .Comment: 4 pages including 4 figure
Assessment of physician well-being, part two: Beyond burnout
© 2019 Lall et al. Part One of this two-article series reviews assessment tools to measure burnout and other negative states. Physician well-being goes beyond merely the absence of burnout. Transient episodes of burnout are to be expected. Measuring burnout alone is shortsighted. Well-being includes being challenged, thriving, and achieving success in various aspects of personal and professional life. In this second part of the series, we identify and describe assessment tools related to wellness, quality of life, resilience, coping skills, and other positive states
Physics of the Insulating Phase in the Dilute Two-Dimensional Electron Gas
We propose to use the radio-frequency single-electron transistor as an
extremely sensitive probe to detect the time-periodic ac signal generated by
sliding electron lattice in the insulating state of the dilute two-dimensional
electron gas. We also propose to use the optically-pumped NMR technique to
probe the electron spin structure of the insulating state. We show that the
electron effective mass and spin susceptibility are strongly enhanced by
critical fluctuations of electron lattice in the vicinity of the
metal-insulator transition, as observed in experiment.Comment: 5 pages, 2 figures, uses jetpl.cls (included). v.4: After publication
in JETP Letters, two plots comparing theory and experiment are added, and a
minor error is correcte
Skyrmion Dynamics and NMR Line Shapes in QHE Ferromagnets
The low energy charged excitations in quantum Hall ferromagnets are
topological defects in the spin orientation known as skyrmions. Recent
experimental studies on nuclear magnetic resonance spectral line shapes in
quantum well heterostructures show a transition from a motionally narrowed to a
broader `frozen' line shape as the temperature is lowered at fixed filling
factor. We present a skyrmion diffusion model that describes the experimental
observations qualitatively and shows a time scale of for
the transport relaxation time of the skyrmions. The transition is characterized
by an intermediate time regime that we demonstrate is weakly sensitive to the
dynamics of the charged spin texture excitations and the sub-band electronic
wave functions within our model. We also show that the spectral line shape is
very sensitive to the nuclear polarization profile along the z-axis obtained
through the optical pumping technique.Comment: 6 pages, 4 figure
Temperature dependence of spin polarizations at higher Landau Levels
We report our results on temperature dependence of spin polarizations at
in the lowest as well as in the next higher Landau level that compare
well with recent experimental results. At , except having a much smaller
magnitude the behavior of spin polarization is not much influenced by higher
Landau levels. In sharp contrast, for filling factor we predict
that unlike the case of the system remains fully spin polarized
even at vanishingly small Zeeman energies.Comment: 4 pages, REVTEX, and 3 .ps files, To be published in Physical Review
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