1,096 research outputs found

    Pulmonary Tuberculosis with Delayed Tuberculosis Infection of Total Knee Arthroplasty

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    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

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    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

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    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

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    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

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    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

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    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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