1,418 research outputs found

    Gottron's Papules Exhibit Dermal Accumulation of CD44 Variant 7 (CD44v7) and Its Binding Partner Osteopontin: A Unique Molecular Signature

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    The accumulated mucin in non-Gottron's dermatomyositis (DM) lesions is primarily chondroitin-4-sulfate (C4S), which is immunomodulatory in vitro. Gottron's papules are a particularly resistant manifestation of DM that often persist after other lesions have resolved with therapy. We examined non-Gottron's DM lesions and Gottron's papule skin biopsies for C4S, CD44 variant 7 (CD44v7), a chondroitin sulfate-binding isoform causally implicated in autoimmunity, and osteopontin (OPN), a CD44v7 ligand implicated in chronic inflammation. Gottron's papule dermis contained more C4S and CD44v7 than non-Gottron's lesions. Normal skin showed less CD44v7 over joints relative to Gottron's lesions. All DM dermis had increased OPN compared with healthy skin. Mechanically stretching cultured fibroblasts for 6hours induced CD44v7 mRNA and protein, whereas IFN-γ treatment induced OPN mRNA and protein. OPN alone did not induce CD44v7, but stretching dermal fibroblasts in the presence of OPN increased human acute monocytic leukemia cell line (THP-1) monocyte binding, which is blunted by anti-CD44v7 blocking antibody. C4S, CD44v7, and OPN are three molecules uniquely present in Gottron's papules that contribute to inflammation individually and in association with one another. We propose that stretch-induced CD44v7 over joints, in concert with dysregulated OPN levels in the skin of DM patients, increases local inflammatory cell recruitment and contributes to the pathogenesis and resistance of Gottron's papules

    Routing Games over Time with FIFO policy

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    We study atomic routing games where every agent travels both along its decided edges and through time. The agents arriving on an edge are first lined up in a \emph{first-in-first-out} queue and may wait: an edge is associated with a capacity, which defines how many agents-per-time-step can pop from the queue's head and enter the edge, to transit for a fixed delay. We show that the best-response optimization problem is not approximable, and that deciding the existence of a Nash equilibrium is complete for the second level of the polynomial hierarchy. Then, we drop the rationality assumption, introduce a behavioral concept based on GPS navigation, and study its worst-case efficiency ratio to coordination.Comment: Submission to WINE-2017 Deadline was August 2nd AoE, 201

    Self-energy correction to the bound-electron g factor in H-like ions

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    The one-loop self-energy correction to the 1s electron g factor is evaluated to all orders in Z\alpha with an accuracy, which is essentially better than that of previous calculations of this correction. As a result, the uncertainty of the theoretical prediction for the bound-electron g factor in H-like carbon is reduced by a factor of 3. This improves the total accuracy of the recent electron-mass determination [Beier et al. Phys. Rev. Lett. 88, 011603 (2002)]. The new value of the electron mass is found to be m_e = 0.000 548 579 909 3(3) u

    Zeeman effect of the hyperfine structure levels in hydrogenlike ions

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    The fully relativistic theory of the Zeeman splitting of the 1s1s hyperfine structure levels in hydrogenlike ions is considered for the magnetic field magnitude in the range from 1 to 10 T. The second-order corrections to the Breit -- Rabi formula are calculated and discussed. The results can be used for a precise determination of nuclear magnetic moments from gg factor experiments.Comment: 13 page

    Evaluation of the self-energy correction to the g-factor of S states in H-like ions

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    A detailed description of the numerical procedure is presented for the evaluation of the one-loop self-energy correction to the gg-factor of an electron in the 1s1s and 2s2s states in H-like ions to all orders in ZαZ\alpha.Comment: Final version, December 30, 200

    Penning traps as a versatile tool for precise experiments in fundamental physics

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    This review article describes the trapping of charged particles. The main principles of electromagnetic confinement of various species from elementary particles to heavy atoms are briefly described. The preparation and manipulation with trapped single particles, as well as methods of frequency measurements, providing unprecedented precision, are discussed. Unique applications of Penning traps in fundamental physics are presented. Ultra-precise trap-measurements of masses and magnetic moments of elementary particles (electrons, positrons, protons and antiprotons) confirm CPT-conservation, and allow accurate determination of the fine-structure constant alpha and other fundamental constants. This together with the information on the unitarity of the quark-mixing matrix, derived from the trap-measurements of atomic masses, serves for assessment of the Standard Model of the physics world. Direct mass measurements of nuclides targeted to some advanced problems of astrophysics and nuclear physics are also presented

    Fabrication of a planar micro Penning trap and numerical investigations of versatile ion positioning protocols

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    We describe a versatile planar Penning trap structure, which allows to dynamically modify the trapping conguration almost arbitrarily. The trap consists of 37 hexagonal electrodes, each with a circumcirle-diameter of 300 m, fabricated in a gold-on-sapphire lithographic technique. Every hexagon can be addressed individually, thus shaping the electric potential. The fabrication of such a device with clean room methods is demonstrated. We illustrate the variability of the device by a detailed numerical simulation of a lateral and a vertical transport and we simulate trapping in racetrack and articial crystal congurations. The trap may be used for ions or electrons, as a versatile container for quantum optics and quantum information experiments.Comment: 10 pages, 7 figures, pdflatex, to be published in New Journal of Physics (NJP) various changes according to the wishes of the NJP referees. Text added and moved around, title changed, abstract changed, references added rev3: one reference had a typo (ref 15), fixed (phys rev a 72, not 71

    g factor of Li-like ions with nonzero nuclear spin

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    The fully relativistic theory of the g factor of Li-like ions with nonzero nuclear spin is considered for the (1s)^2 2s state. The magnetic-dipole hyperfine-interaction correction to the atomic g factor is calculated including the one-electron contributions as well as the interelectronic-interaction effects of order 1/Z. This correction is combined with the interelectronic-interaction, QED, nuclear recoil, and nuclear size corrections to obtain high-precision theoretical values for the g factor of Li-like ions with nonzero nuclear spin. The results can be used for a precise determination of nuclear magnetic moments from g factor experiments.Comment: 20 pages, 5 figure

    Recoil correction to the bound-electron g factor in H-like atoms to all orders in αZ\alpha Z

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    The nuclear recoil correction to the bound-electron g factor in H-like atoms is calculated to first order in m/Mm/M and to all orders in αZ\alpha Z. The calculation is performed in the range Z=1-100. A large contribution of terms of order (αZ)5(\alpha Z)^5 and higher is found. Even for hydrogen, the higher-order correction exceeds the (αZ)4(\alpha Z)^4 term, while for uranium it is above the leading (αZ)2(\alpha Z)^2 correction.Comment: 6 pages, 3 tables, 1 figur
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