19,509 research outputs found

    First axion dark matter search with toroidal geometry

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    We firstly report an axion haloscope search with toroidal geometry. In this pioneering search, we exclude the axion-photon coupling gaγγg_{a\gamma\gamma} down to about 5×1085\times10^{-8} GeV1^{-1} over the axion mass range from 24.7 to 29.1 μ\mueV at a 95\% confidence level. The prospects for axion dark matter searches with larger scale toroidal geometry are also considered.Comment: 5 pages, 5 figures, 1 table and to appear in PRD-R

    Far Ultraviolet Observations of the Dwarf Nova VW Hyi in Quiescence

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    We present a 904-1183 A spectrum of the dwarf nova VW Hydri taken with the Far Ultraviolet Spectroscopic Explorer during quiescence, eleven days after a normal outburst, when the underlying white dwarf accreter is clearly exposed in the far ultraviolet. However, model fitting show that a uniform temperature white dwarf does not reproduce the overall spectrum, especially at the shortest wavelengths. A better approximation to the spectrum is obtained with a model consisting of a white dwarf and a rapidly rotating ``accretion belt''. The white dwarf component accounts for 83% of the total flux, has a temperature of 23,000K, a v sin i = 400 km/s, and a low carbon abundance. The best-fit accretion belt component accounts for 17% of the total flux, has a temperature of about 48,000-50,000K, and a rotation rate Vrot sin i around 3,000-4,000 km/s. The requirement of two components in the modeling of the spectrum of VW Hyi in quiescence helps to resolve some of the differences in interpretation of ultraviolet spectra of VW Hyi in quiescence. However, the physical existence of a second component (and its exact nature) in VW Hyi itself is still relatively uncertain, given the lack of better models for spectra of the inner disk in a quiescent dwarf nova.Comment: 6 figures, 10 printed page in the journal, to appear in APJ, 1 Sept. 2004 issue, vol. 61

    Hydroxyapatite Nanocrystal Deposition on Plasma Modified Titanium Surface

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    Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) is materials mainly known for its special ability to contact bone tissue. Nanostructures on implant surfaces, a coating composed of nano-HAp particles on Ti, have aroused increasing research interest in the biomedical field. In this study, we prepared HAp nanocrystal coated Ti surface by plasma surface modification and wet chemical method and then evaluated biological behavior of MC3T3-E1 on the HAp coated on plasma modified Ti surface. Nano-size crystals of sintered HAp were uniformly coated on polyacrylic acid (PAA) deposited Ti surface through the ionic interaction between calcium ions on the HAp nanocrystal and carboxyl groups on the PAA/Ti. In vitro cell tests revealed surface modification of Ti surface with HAp nanocrystal significantly improved the proliferation and growth of the osteoblastic MC3T3-E1 cells and induced them to differentiate at an enhanced level. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3495

    Forty-Four Pass Fibre Optic Loop for Improving the Sensitivity of Surface Plasmon Resonance Sensors

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    A forty-four pass fibre optic surface plasmon resonance sensor that enhances detection sensitivity according to the number of passes is demonstrated for the first time. The technique employs a fibre optic recirculation loop that passes the detection spot forty- four times, thus enhancing sensitivity by a factor of forty-four. Presently, the total number of passes is limited by the onset of lasing action of the recirculation loop. This technique offers a significant sensitivity improvement for various types of plasmon resonance sensors that may be used in chemical and biomolecule detections.Comment: Submitted for publication; patent disclosure submitte

    Search for X(3872) in gamma gamma Fusion and ISR at CLEO

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    We report on a search for the X(3872) state using 15.1 fb^{-1} of e+ e- annihilation data taken with the CLEO III detector in the sqrt{s} = 9.46-11.30 GeV region. Separate searches for the production of X(3872) in untagged gamma gamma fusion and e+ e- annihilation following initial state radiation are made by taking advantage of the unique correlation of J/psi -> l+ l- in X(3872) decay into J/psi pi+ pi-. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)Gamma_{gammagamma}(X(3872))B(X -> J/psi pi+ pi-) J/psi pi+ pi-) < 8.3 eV.Comment: 4 pages, 2 figures, to appear in the proceedings of the 1st Meeting of the APS Topical Group on Hadronic Physics, Fermilab, Oct. 24-26, 200

    A Multi-Phase Transport model for nuclear collisions at RHIC

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    To study heavy ion collisions at energies available from the Relativistic Heavy Ion Collider, we have developed a multi-phase transport model that includes both initial partonic and final hadronic interactions. Specifically, the parton cascade model ZPC, which uses as input the parton distribution from the HIJING model, is extended to include the quark-gluon to hadronic matter transition and also final-state hadronic interactions based on the ART model. Predictions of the model for central Au on Au collisions at RHIC are reported.Comment: 7 pages, 4 figure

    IL-17A Promotes Pulmonary B-1a Cell Differentiation via Induction of Blimp-1 Expression during Influenza Virus Infection

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    B-1 cells play a critical role in early protection during influenza infections by producing natural IgM antibodies. However, the underlying mechanisms involved in regulating this process are largely unknown. Here we found that during influenza infection pleural cavity B-1a cells rapidly infiltrated lungs, where they underwent plasmacytic differentiation with enhanced IgM production. This process was promoted by IL-17A signaling via induction of Blimp-1 expression and NF-kB activation in B-1a cells. Deficiency of IL-17A led to severely impaired B-1a-derived antibody production in the respiratory tract, resulting in a deficiency in viral clearance. Transfer of B-1a-derived natural antibodies rescued Il17a(-/-) mice from otherwise lethal infections. Together, we identify a critical function of IL-17A in promoting the plasmacytic differentiation of B-1a cells. Our findings provide new insights into the mechanisms underlying the regulation of pulmonary B-1a cell response against influenza infection.published_or_final_versio
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