96 research outputs found

    The Madison plasma dynamo experiment: a facility for studying laboratory plasma astrophysics

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    The Madison plasma dynamo experiment (MPDX) is a novel, versatile, basic plasma research device designed to investigate flow driven magnetohydrodynamic (MHD) instabilities and other high-β\beta phenomena with astrophysically relevant parameters. A 3 m diameter vacuum vessel is lined with 36 rings of alternately oriented 4000 G samarium cobalt magnets which create an axisymmetric multicusp that contains ∼\sim14 m3^{3} of nearly magnetic field free plasma that is well confined and highly ionized (>50%)(>50\%). At present, 8 lanthanum hexaboride (LaB6_6) cathodes and 10 molybdenum anodes are inserted into the vessel and biased up to 500 V, drawing 40 A each cathode, ionizing a low pressure Ar or He fill gas and heating it. Up to 100 kW of electron cyclotron heating (ECH) power is planned for additional electron heating. The LaB6_6 cathodes are positioned in the magnetized edge to drive toroidal rotation through J×B{\bf J}\times{\bf B} torques that propagate into the unmagnetized core plasma. Dynamo studies on MPDX require a high magnetic Reynolds number Rm>1000Rm > 1000, and an adjustable fluid Reynolds number 10<Re<100010< Re <1000, in the regime where the kinetic energy of the flow exceeds the magnetic energy (MA2=(M_A^2=(v//vA)2>1_A)^2 > 1). Initial results from MPDX are presented along with a 0-dimensional power and particle balance model to predict the viscosity and resistivity to achieve dynamo action.Comment: 14 pages, 13 figure

    Non-Lorentzian single-molecule line shape: Pseudolocal phonons and coherence transfer

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    The excitation line shape of a single terrylene molecule in a naphthalene crystal has been investigated. In addition to the conventional Lorentzian, it consists of a dispersive component in the core region and a sideband. This is due to a pseudolocal phonon caused by the substitution of a host molecule with the chromophore. When the pseudolocal phonon is excited, the resonance frequency of the chromophore slightly changes, resulting in the appearance of a second, quasiresonant transition. Coherence transfer between these two optical transitions causes the deviation from the purely Lorentzian line shape

    Maternal COVID-19 causing intrauterine foetal demise with microthrombotic placental insufficiency: a case report

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    BACKGROUND: Pregnant women have an increased risk of getting infected with SARS-CoV-2 and are more prone to severe illness. Data on foetal demise in affected pregnancies and its underlying aetiology is scarce and pathomechanisms remain largely unclear. CASE: Herein we present the case of a pregnant woman with COVID-19 and intrauterine foetal demise. She had no previous obstetric or gynaecological history, and presented with mild symptoms at 34 + 3 weeks and no signs of foetal distress. At 35 + 6 weeks intrauterine foetal death was diagnosed. In the placental histopathology evaluation, we found inter- and perivillous fibrin depositions including viral particles in areas of degraded placental anatomy without presence of viral entry receptors and SARS-CoV-2 infection of the placenta. CONCLUSION: This case demonstrates that maternal SARS-CoV-2 infection in the third trimester may lead to an unfavourable outcome for the foetus due to placental fibrin deposition in maternal COVID-19 disease possibly via a thrombogenic microenvironment, even when the foetus itself is not infected

    Ginger inhibits cell growth and modulates angiogenic factors in ovarian cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Ginger (<it>Zingiber officinale </it>Rosc) is a natural dietary component with antioxidant and anticarcinogenic properties. The ginger component [6]-gingerol has been shown to exert anti-inflammatory effects through mediation of NF-κB. NF-κB can be constitutively activated in epithelial ovarian cancer cells and may contribute towards increased transcription and translation of angiogenic factors. In the present study, we investigated the effect of ginger on tumor cell growth and modulation of angiogenic factors in ovarian cancer cells <it>in vitro</it>.</p> <p>Methods</p> <p>The effect of ginger and the major ginger components on cell growth was determined in a panel of epithelial ovarian cancer cell lines. Activation of NF-κB and and production of VEGF and IL-8 was determined in the presence or absence of ginger.</p> <p>Results</p> <p>Ginger treatment of cultured ovarian cancer cells induced profound growth inhibition in all cell lines tested. We found that <it>in vitro</it>, 6-shogaol is the most active of the individual ginger components tested. Ginger treatment resulted in inhibition of NF-kB activation as well as diminished secretion of VEGF and IL-8.</p> <p>Conclusion</p> <p>Ginger inhibits growth and modulates secretion of angiogenic factors in ovarian cancer cells. The use of dietary agents such as ginger may have potential in the treatment and prevention of ovarian cancer.</p

    Report to DOE on the evaluation of initial trapping studies

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    This report summarizes work up to Dec. 1, 1978 on the single mirror plug of Phaedrus. The design, construction and initial experiments proceeded without major problems. The results on RF trapping and heating steadily improved during the months of October and November with our best results being obtained during the last two weeks of November. These positive results are encouraging for RF heating in mirrors. The experiments to date have concentrated on heating stream gun plasmas. This plasma source has been well suited for our initial studies as it produces a hot, dense plasma over a long duration (approx. 1 msec). This has made diagnostics particularly straight forward. Because of the time scale we have carried out most of our work with the 200 kW source which is capable of running for long pulses (30 msec)

    Whistler-mode electron cyclotron emission from the Phaedrus-B end cell

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    This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder

    Whistler-mode electron cyclotron emission from the Phaedrus-B end cell

    No full text
    This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder
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