2,717 research outputs found
Outcome Analysis of Intra-Articular Scapula Fracture Fixation with Distal Radius Plate: A Multicenter Prospective Study
Background: Scapula fractures occur in approximately 1% of all fractures and constitute about 3% - 5% of all injuries of the shoulder joint.
Objectives: This study aimed to evaluate the clinical outcomes of 20 surgically treated patients with displaced glenoid fractures after stabilization with distal radius plate.
Methods: Between 2012 and 2015, at 2 centers (HMCH & SHCE) of Bhubaneswar Odisha, we stabilized 20 scapular intra-articular fractures surgically with distal radius locking plate and studied the outcome of the surgeries. The outcome of the 20 fractures was determined using the Constant and Murley score. Both shoulders were assessed and the score on the injured side was given as a percentage of that on the uninjured side.
Results: The median score was 88% (mean 65%, range 30 to 100). The median score for strength was 21/25 (mean 19, range 0 to 25) and that for pain 11/15 (mean 11, range 5 to 15). The median functional score was 16/20 (mean 15, range 0 to 20). The mean range of active abduction of the shoulder was 135° (20 to 180), the mean range of flexion 138° (20 to 180) and the mean range of external rotation 38° (0 to 100). Five patients showed excellent result; 11 patients showed good result; three patients showed fair result and one patient had poor outcome according to the Constant-Murley score. A superficial infection settled with antibiotics after operation in one patient whose score at final follow-up was 96%. In one patient, delayed healing was reported because of infection. One patient with stiffness of the shoulder at six weeks underwent manipulation under anesthesia with a follow-up score of 81%.
Conclusions: Various fixation modalities have been described in the literature, however fixation of intra-articular fracture of glenoid with distal radius locking plate for articular reconstruction in the presented series provides good functional outcome with early restoration of the range of motion of the shoulder
Neural Network Model for Apparent Deterministic Chaos in Spontaneously Bursting Hippocampal Slices
A neural network model that exhibits stochastic population bursting is
studied by simulation. First return maps of inter-burst intervals exhibit
recurrent unstable periodic orbit (UPO)-like trajectories similar to those
found in experiments on hippocampal slices. Applications of various control
methods and surrogate analysis for UPO-detection also yield results similar to
those of experiments. Our results question the interpretation of the
experimental data as evidence for deterministic chaos and suggest caution in
the use of UPO-based methods for detecting determinism in time-series data.Comment: 4 pages, 5 .eps figures (included), requires psfrag.sty (included
Correlation of Clinical Examination, MRI and Arthroscopy Findings in Menisco-Cruciate Injuries of the Knee: A Prospective Diagnostic Study
Background: The aim of this study was to examine the correlation of the clinical examination, MRI and arthroscopic findings in cruciate ligaments and meniscal injuries of knee and to evaluate the accuracy of clinical examination and MRI with the gold standard arthroscopy.
Methods: A prospective diagnostic double-blind study was conducted on 104 consecutive patients admitted to the outdoor/casualty with trauma to the knee complaining of knee pain/locking/ instability, from August 2012 to June 2014. All the patients were subjected to clinical examination, MRI scanning and diagnostic arthroscopy. Variables like sensitivity, specificity, positive predictive value, negative predictive value and accuracy of clinical examination and MRI against arthroscopy were evaluated.
Results: The sensitivity, specificity and accuracy of clinical examination for anterior cruciate ligament tears were 94.7%, 71.4% and 88.5% and for MRI were 94.7%, 78.6% and 90.4%, respectively; for posterior cruciate ligament tears 100%, 100% and 100% for clinical examination and for MRI 80%, 97.9% and 96.2%, respectively. These values for medial meniscus tears were 76.5%, 68.6% and 71.2% for clinical examination and 88.2%, 62.8% and 71.2% respectively for MRI. For lateral meniscus tears, 40%, 94.6% and 78.8% for clinical examination and 46.7%, 89.2% and 76.9% respectively for MRI.
Conclusions: A skillfully performed clinical examination establishes a diagnosis on which an arthroscopic procedure can be planned, reserving MRI scans for patients where the clinical examination fails to establish a diagnosis or cannot be performed. Decision to use MRI should be based on the criteria that it would confirm, expand the diagnosis or change diagnosis in such a way that alters the proposed treatment
Stochastic reconstruction of sandstones
A simulated annealing algorithm is employed to generate a stochastic model
for a Berea and a Fontainebleau sandstone with prescribed two-point probability
function, lineal path function, and ``pore size'' distribution function,
respectively. We find that the temperature decrease of the annealing has to be
rather quick to yield isotropic and percolating configurations. A comparison of
simple morphological quantities indicates good agreement between the
reconstructions and the original sandstones. Also, the mean survival time of a
random walker in the pore space is reproduced with good accuracy. However, a
more detailed investigation by means of local porosity theory shows that there
may be significant differences of the geometrical connectivity between the
reconstructed and the experimental samples.Comment: 12 pages, 5 figure
Crystal structure and magnetic properties of spin- frustrated two-leg ladder compounds (CHN)Cu (= Cl and Br)
We have successfully synthesized single crystals, solved the crystal
structure, and studied the magnetic properties of a new family of copper
halides (CHN)Cu (= Cl, Br). These compounds
crystallize in an orthorhombic crystal structure with space group . The
crystal structure features Cu dimers arranged parallel to each other
that makes a zig-zag two-leg ladder-like structure. Further, there exists a
diagonal interaction between two adjacent dimers which generates inter-dimer
frustration. Both the compounds manifest a singlet ground state with a large
gap in the excitation spectrum. Magnetic susceptibility is analyzed in terms of
both interacting spin- dimer and two-leg ladder models followed by exact
diagonalization calculations. Our theoretical calculations in conjunction with
the experimental magnetic susceptibility establish that the spin-lattice can be
described well by a frustrated two-leg ladder model with strong rung coupling
( K and 300 K), weak leg coupling
( K and 105 K), and equally weak
diagonal coupling ( K and 90 K) for Cl and
Br compounds, respectively. These exchange couplings set the critical fields
very high, making them experimentally inaccessible. The correlation function
decays exponentially as expected for a gapped spin system. The structural
aspects of both the compounds are correlated with their magnetic properties.
The calculation of entanglement witness divulges strong entanglement in both
the compounds which persists upto high temperatures, even beyond 370~K for the
Br compound.Comment: 13 pages, 9 figures, 2 table
Lattice-Boltzmann and finite-difference simulations for the permeability for three-dimensional porous media
Numerical micropermeametry is performed on three dimensional porous samples
having a linear size of approximately 3 mm and a resolution of 7.5 m. One
of the samples is a microtomographic image of Fontainebleau sandstone. Two of
the samples are stochastic reconstructions with the same porosity, specific
surface area, and two-point correlation function as the Fontainebleau sample.
The fourth sample is a physical model which mimics the processes of
sedimentation, compaction and diagenesis of Fontainebleau sandstone. The
permeabilities of these samples are determined by numerically solving at low
Reynolds numbers the appropriate Stokes equations in the pore spaces of the
samples. The physical diagenesis model appears to reproduce the permeability of
the real sandstone sample quite accurately, while the permeabilities of the
stochastic reconstructions deviate from the latter by at least an order of
magnitude. This finding confirms earlier qualitative predictions based on local
porosity theory. Two numerical algorithms were used in these simulations. One
is based on the lattice-Boltzmann method, and the other on conventional
finite-difference techniques. The accuracy of these two methods is discussed
and compared, also with experiment.Comment: to appear in: Phys.Rev.E (2002), 32 pages, Latex, 1 Figur
Interface pinning and slow ordering kinetics on infinitely ramified fractal structures
We investigate the time dependent Ginzburg-Landau (TDGL) equation for a non
conserved order parameter on an infinitely ramified (deterministic) fractal
lattice employing two alternative methods: the auxiliary field approach and a
numerical method of integration of the equations of evolution. In the first
case the domain size evolves with time as , where is
the anomalous random walk exponent associated with the fractal and differs from
the normal value 2, which characterizes all Euclidean lattices. Such a power
law growth is identical to the one observed in the study of the spherical model
on the same lattice, but fails to describe the asymptotic behavior of the
numerical solutions of the TDGL equation for a scalar order parameter. In fact,
the simulations performed on a two dimensional Sierpinski Carpet indicate that,
after an initial stage dominated by a curvature reduction mechanism \`a la
Allen-Cahn, the system enters in a regime where the domain walls between
competing phases are pinned by lattice defects.
The lack of translational invariance determines a rough free energy
landscape, the existence of many metastable minima and the suppression of the
marginally stable modes, which in translationally invariant systems lead to
power law growth and self similar patterns. On fractal structures as the
temperature vanishes the evolution is frozen, since only thermally activated
processes can sustain the growth of pinned domains.Comment: 16 pages+14 figure
A crystalline, 2D polyarylimide cathode for ultrastable and ultrafast Li storage
Organic electrode materials are of long‐standing interest for next‐generation sustainable lithium‐ion batteries (LIBs). As a promising cathode candidate, imide compounds have attracted extensive attention due to their low cost, high theoretical capacity, high working voltage, and fast redox reaction. However, the redox active site utilization of imide electrodes remains challenging for them to fulfill their potential applications. Herein, the synthesis of a highly stable, crystalline 2D polyarylimide (2D‐PAI) integrated with carbon nanotube (CNT) is demonstrated for the use as cathode material in LIBs. The synthesized polyarylimide hybrid (2D‐PAI@CNT) is featured with abundant π‐conjugated redox‐active naphthalene diimide units, a robust cyclic imide linkage, high surface area, and well‐defined accessible pores, which render the efficient utilization of redox active sites (82.9%), excellent structural stability, and fast ion diffusion. As a consequence, high rate capability and ultrastable cycle stability (100% capacity retention after 8000 cycles) are achieved in the 2D‐PAI@CNT cathode, which far exceeds the state‐of‐the‐art polyimide electrodes. This work may inspire the development of novel organic electrodes for sustainable and durable rechargeable batteries
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