1,100 research outputs found
Pulmonary Tuberculosis with Delayed Tuberculosis Infection of Total Knee Arthroplasty
Tuberculous prosthetic joint infection is rare. While early diagnosis is critical for treatment, it is usually delayed. Here, we present the case of a 72-year-old patient who underwent total knee arthroplasty for his right knee due to degenerative arthritis 4 years ago. Three years after arthroplasty, pulmonary tuberculosis was found and he hesitated on starting antituberculosis chemotherapy. He suffered from progressive pain and swelling of the right prosthetic knee for 2 months before this admission. The pathologic report of the debridement of the right prosthetic knee was caseous granulomatous inflammation with positive acid-fast staining bacilli. The culture of the debridement also yielded Mycobacterium tuberculosis. He died due to aspiration pneumonia with multiorgan dysfunction. This case is a reminder of the possibility of tuberculosis while dealing with prosthetic joint infection. [J Formos Med Assoc 2007;106(1):82-85
Interaction induced ferro-electricity in the rotational states of polar molecules
We show that a ferro-electric quantum phase transition can be driven by the
dipolar interaction of polar molecules in the presence a micro-wave field. The
obtained ferro-electricity crucially depends on the harmonic confinement
potential, and the resulting dipole moment persists even when the external
field is turned off adiabatically. The transition is shown to be second order
for fermions and for bosons of a smaller permanent dipole moment, but is first
order for bosons of a larger moment. Our results suggest the possibility of
manipulating the microscopic rotational state of polar molecules by tuning the
trap's aspect ratio (and other mesoscopic parameters), even though the later's
energy scale is smaller than the former's by six orders of magnitude.Comment: 4 pages and 4 figure
CALIBRATION OF PRESSURE SENSORS FOR HAND GRIP MEASUREMENT
The purpose of this study was to assess the accuracy of grip force sensors. Methods: Several standard weights were used to calibrate the grip sensor in the static condition, The descriptive statistics and linear regression were used to present the accuracy and errors. Results: Results of this study showed a high level of sensing areas linear relationship under static loading. Conclusion: Data from this study showed high accuracy of the pressure sensor. The pressure sensor could te used for hand grip measurement
When Social Influence Meets Item Inference
Research issues and data mining techniques for product recommendation and
viral marketing have been widely studied. Existing works on seed selection in
social networks do not take into account the effect of product recommendations
in e-commerce stores. In this paper, we investigate the seed selection problem
for viral marketing that considers both effects of social influence and item
inference (for product recommendation). We develop a new model, Social Item
Graph (SIG), that captures both effects in form of hyperedges. Accordingly, we
formulate a seed selection problem, called Social Item Maximization Problem
(SIMP), and prove the hardness of SIMP. We design an efficient algorithm with
performance guarantee, called Hyperedge-Aware Greedy (HAG), for SIMP and
develop a new index structure, called SIG-index, to accelerate the computation
of diffusion process in HAG. Moreover, to construct realistic SIG models for
SIMP, we develop a statistical inference based framework to learn the weights
of hyperedges from data. Finally, we perform a comprehensive evaluation on our
proposals with various baselines. Experimental result validates our ideas and
demonstrates the effectiveness and efficiency of the proposed model and
algorithms over baselines.Comment: 12 page
Local geometry and quantum geometric tensor of mixed states
The quantum geometric tensor (QGT) is a fundamental concept for
characterizing the local geometry of quantum states. After casting the geometry
of pure quantum states and extracting the QGT, we generalize the geometry to
mixed quantum states via the density matrix and its purification. The
gauge-invariant QGT of mixed states is derived, whose real and imaginary parts
are the Bures metric and the Uhlmann form, respectively. In contrast to the
imaginary part of the pure-state QGT that is proportional to the Berry
curvature, the Uhlmann form vanishes identically for ordinary physical
processes. Moreover, there exists a Pythagorean-like equation that links
different local distances and reflect the underlying fibration. The Bures
metric reduces to the Fubini-Study metric as temperature approaches zero if the
eigenvalues of the density matrix do not change during the process,
establishing a correspondence between pure and mixed states. We also present
two examples with contrasting local geometries and discuss experimental
implications.Comment: 22 pages, 3 figure
Geometric phases of mixed quantum states: A comparative study of interferometric and Uhlmann phases
Two geometric phases of mixed quantum states, known as the interferometric
phase and Uhlmann phase, are generalizations of the Berry phase of pure states.
After reviewing the two geometric phases and examining their parallel-transport
conditions, we specify a class of cyclic processes that are compatible with
both conditions and therefore accumulate both phases through their definitions,
respectively. Those processes then facilitate a fair comparison between the two
phases. We present exact solutions of two-level and three-level systems to
contrast the two phases. While the interferometric phase exhibits
finite-temperature transitions only in the three-level system but not the
two-level system, the Uhlmann phase shows finite-temperature transitions in
both cases. Thus, using the two geometric phases as finite-temperature
topological indicators demonstrates the rich physics of topology of mixed
states.Comment: 12 pages, 2 figures, submitte
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