Search Results - (Author, Cooperation:T. Johansen)

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  1. 1
    R. Do ; N. O. Stitziel ; H. H. Won ; A. B. Jorgensen ; S. Duga ; P. Angelica Merlini ; A. Kiezun ; M. Farrall ; A. Goel ; O. Zuk ; I. Guella ; R. Asselta ; L. A. Lange ; G. M. Peloso ; P. L. Auer ; D. Girelli ; N. Martinelli ; D. N. Farlow ; M. A. DePristo ; R. Roberts ; A. F. Stewart ; D. Saleheen ; J. Danesh ; S. E. Epstein ; S. Sivapalaratnam ; G. K. Hovingh ; J. J. Kastelein ; N. J. Samani ; H. Schunkert ; J. Erdmann ; S. H. Shah ; W. E. Kraus ; R. Davies ; M. Nikpay ; C. T. Johansen ; J. Wang ; R. A. Hegele ; E. Hechter ; W. Marz ; M. E. Kleber ; J. Huang ; A. D. Johnson ; M. Li ; G. L. Burke ; M. Gross ; Y. Liu ; T. L. Assimes ; G. Heiss ; E. M. Lange ; A. R. Folsom ; H. A. Taylor ; O. Olivieri ; A. Hamsten ; R. Clarke ; D. F. Reilly ; W. Yin ; M. A. Rivas ; P. Donnelly ; J. E. Rossouw ; B. M. Psaty ; D. M. Herrington ; J. G. Wilson ; S. S. Rich ; M. J. Bamshad ; R. P. Tracy ; L. A. Cupples ; D. J. Rader ; M. P. Reilly ; J. A. Spertus ; S. Cresci ; J. Hartiala ; W. H. Tang ; S. L. Hazen ; H. Allayee ; A. P. Reiner ; C. S. Carlson ; C. Kooperberg ; R. D. Jackson ; E. Boerwinkle ; E. S. Lander ; S. M. Schwartz ; D. S. Siscovick ; R. McPherson ; A. Tybjaerg-Hansen ; G. R. Abecasis ; H. Watkins ; D. A. Nickerson ; D. Ardissino ; S. R. Sunyaev ; C. J. O'Donnell ; D. Altshuler ; S. Gabriel ; S. Kathiresan
    Nature Publishing Group (NPG)
    Published 2014
    Staff View
    Publication Date:
    2014-12-10
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Age Factors ; Age of Onset ; *Alleles ; Apolipoproteins A/*genetics ; Case-Control Studies ; Cholesterol, LDL/blood ; Coronary Artery Disease/genetics ; Exome/*genetics ; Female ; Genetic Predisposition to Disease/*genetics ; Genetics, Population ; Heterozygote ; Humans ; Male ; Middle Aged ; Mutation/genetics ; Myocardial Infarction/blood/*genetics ; National Heart, Lung, and Blood Institute (U.S.) ; Receptors, LDL/*genetics ; Triglycerides/blood ; United States
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Staff View
    Publication Date:
    2015-11-03
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Adaptor Proteins, Signal Transducing/metabolism ; Animals ; *Autophagy ; Cell Aging ; Cell Transformation, Neoplastic ; Cells, Cultured ; Chromatin/chemistry/metabolism ; Cytoplasm/metabolism ; Fibroblasts ; HEK293 Cells ; Humans ; Lamin Type B/genetics/metabolism ; Lysosomes/metabolism ; Mice ; Microfilament Proteins/metabolism ; Microtubule-Associated Proteins/metabolism ; Nuclear Lamina/*metabolism ; Oncogene Protein p21(ras)/metabolism ; Protein Binding ; Proteolysis
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Staff View
    Publication Date:
    2015-04-10
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Animals ; Binding Sites ; Biological Transport ; Cell Line ; Cell Membrane/metabolism ; DNA-Binding Proteins/metabolism ; Endoplasmic Reticulum/*metabolism ; Endosomes/*metabolism ; HeLa Cells ; Humans ; Kinesin/metabolism ; Microtubules/metabolism ; Neurites/*metabolism ; Phosphatidylinositol Phosphates/metabolism ; Rats ; Synaptotagmins/metabolism ; Transcription Factors/metabolism ; Vesicular Transport Proteins/metabolism ; rab GTP-Binding Proteins/metabolism
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  4. 4
    Staff View
    Publication Date:
    2018-02-16
    Publisher:
    American Society of Hematology (ASH)
    Print ISSN:
    0006-4971
    Electronic ISSN:
    1528-0020
    Topics:
    Biology
    Medicine
    Keywords:
    Free Research Articles, Lymphoid Neoplasia
    Published by:
    http://www.hematology.org/

    Latest Papers from Table of Contents or Articles in Press
  5. 5
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    Publication Date:
    2018-05-27
    Publisher:
    BMJ Publishing
    Electronic ISSN:
    2044-6055
    Topics:
    Medicine
    Keywords:
    Open access, Public health
    Published by:
    http://group.bmj.com/

    Latest Papers from Table of Contents or Articles in Press
  6. 6
    Staff View
    Publication Date:
    2018-03-28
    Publisher:
    American Physical Society (APS)
    Print ISSN:
    1098-0121
    Electronic ISSN:
    1095-3795
    Topics:
    Physics
    Keywords:
    Structure, structural phase transitions, mechanical properties, defects
    Published by:
    http://www.aps.org/

    Latest Papers from Table of Contents or Articles in Press
  7. 7
    Yang, Z. J. ; Johansen, T. H. ; Bratsberg, H. ; Helgesen, G. ; Skjeltorp, A. T.

    [S.l.] : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Based on Davis' model for the lateral restoring force on a magnet levitated above a superconductor [J. Appl. Phys. 67, 2631 (1990)], we calculate the restoring force as a function of lateral displacement for a more realistic magnetic field profile.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.346297

    Articles: DFG German National Licenses
  8. 8
    Johansen, T. H. ; Bratsberg, H. ; Yang, Z. J. ; Guo, S. J. ; Loberg, B.

    [S.l.] : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Using quasistatic harmonic excitations, we have measured the lateral force between a permanent magnet and a Bi-based ceramic high-Tc superconductor (HTSC) for lateral displacement amplitudes down to 1 μm. We find clear evidence for a transition from elastic (nondissipative) to inelastic interaction, and attribute the effect to flux pinning. The crossover amplitude can easily reach several micrometers, with the consequence that the lateral disturbance of a levitated magnet will decay to this amplitude, whereas further damping will be extremely slow. For applications of HTSCs in magnetic bearing systems this can be a very relevant aspect of the interaction, and it can set the limit for precision positioning of levitated objects.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.350365

    Articles: DFG German National Licenses
  9. 9
    Johansen, T. H.

    [S.l.] : American Institute of Physics (AIP)
    Published 2000
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The mechanical stress caused by flux pinning in a cylindrical superconductor with a concentric hole is investigated theoretically. Exact expressions for the radial and hoop stress are derived using the critical-state model. Stress profiles during a magnetization process often used to activate high-Tc superconductors as strong trapped-field magnets are presented and analyzed in detail. It is shown that due to the hole the tensile hoop stress is enhanced by a factor of 2 or more, depending on the hole diameter. The dramatic increase in cracking probability is emphasized. © 2000 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.1287123

    Articles: DFG German National Licenses
  10. 10
    Johansen, T. H. ; Mestl, H. ; Bratsberg, H.

    [S.l.] : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A new experimental setup has been designed to measure with high-resolution the horizontal force between a permanent magnet levitating over a high-temperature superconductor. We have studied the lateral stability as well as elastic stiffness associated with small-amplitude (〈10 μm) vibrational motion both as functions of levitation height and relative horizontal displacements. The results, obtained for a sintered sample of YBa2Cu3Ox and a NdFeB magnet of rectangular geometry, are found to agree well with a recent quantitative theory applicable to granular superconductors.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.356351

    Articles: DFG German National Licenses
  11. 11
    Johansen, T. H. ; Bratsberg, H.

    [S.l.] : American Institute of Physics (AIP)
    Published 1995
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A scheme is described for analytical calculation of critical-state magnetization M of superconductors in the geometry of long rectangular slabs and cylindrical specimens in a parallel magnetic field. The simplicity of the general scheme is demonstrated by deriving compact expressions for the ascending and descending field branches of M in the exponential model Jc=jc0 exp(−B/B0) and in the Kim, Hempstead, and Strnad model [Phys. Rev. 129, 528 (1963)], Jc=jc0/(1+B/B0). The analyses focus on the vertical width ΔM of large field magnetization hysteresis loops. While Bean's result [Phys. Rev. Lett. 8, 250 (1962)], Jc∝ΔM, today is used extensively to infer the critical current, it is well known that the method lacks consistency when a field dependence is seen in ΔM. For the two models it is shown explicitly that in the expansion of the functional relation ΔM(Jc), Bean's result corresponds to the lowest-order term. Also to the next order in the functional expansion we find a unifying form of expressing the model behaviors. This term contains the second derivative of J2c(B) with a prefactor that depends on the sample geometry. A model-independent proof for the two first terms in the expansion of ΔM(Jc) is also given, which allows the significance of size and shape, i.e., thickness and aspect ratio, to be discussed on a general basis. New methods to extract Jc from ΔM data, one of them without having to invoke specific critical-state models, are indicated. © 1995 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.358576

    Articles: DFG German National Licenses
  12. 12
    Johansen, T. H. ; Bratsberg, H.

    [S.l.] : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We propose a critical-state model based on the empirical fact that the critical current density Jc in high-Tc superconductors in some cases is found to decay to an essentially field independent level at large inductions B. The new critical current function, Jc(||B||), consists of a constant plus a field dependent term of the Kim model type. Analytical expressions for internal induction profiles and the entire shape of major magnetization loops, as well as the initial branch, are derived for the infinite slab geometry. As an illustration it is shown that the new model gives a precise overall description of a magnetization loop measured for melt processed YBa2Cu3Ox. © 1994 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.357917

    Articles: DFG German National Licenses
  13. 13
    Johansen, T. H. ; Yang, Z. J. ; Bratsberg, H. ; Helgesen, G. ; Skjeltorp, A. T.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The lateral force interaction between a permanent bar magnet and a large slab of high Tc superconductor has been investigated at 77 K, under conditions of a constant vertical separation of 2 mm. The restoring force as a function of lateral displacement rises very steeply, and reaches 90% of its saturation value, 5.1 mN, after 1.8 mm. The profile of the force-displacement curve is in qualitative agreement with the existing theory. A significant quantitative discrepancy is interpreted as due to a theoretical penetration depth exceeding the sample thickness. The lateral magnetic stiffness or spring constant, is found to be independent of displacement away from lateral equilibrium.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.104965

    Articles: DFG German National Licenses
  14. 14
    Koblischka, M. R. ; Johansen, T. H. ; Bratsberg, H.

    [S.l.] : American Institute of Physics (AIP)
    Published 1998
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Flux patterns of multifilamentary Ag-sheathed (Pb,Bi)2Sr2Ca2Cu3O10+δ tapes comprising 19 filaments are visualized by means of magneto-optic imaging. In low fields, the shielding currents are seen to flow mainly in the outermost filaments. With increasing external magnetic field, the inner filaments also contribute to the current flow. To compare the local flux distribution with the integral magnetization values, magnetization loops are measured by a SQUID magnetometer on the same sample following the fields used in the magneto-optic imaging (± 120 mT) and covering fields up to ±5 T at various temperatures. The magnetization loops also reveal that the multifilamentary tapes show the anomalous position of the central peak, but always less pronounced than in monofilamentary tapes. © 1998 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.367865

    Articles: DFG German National Licenses
  15. 15
    Johansen, T. H. ; Feder, J. ; Jøssang, T.

    [S.l.] : American Institute of Physics (AIP)
    Published 1986
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    A fully automated apparatus has been designed for measurements of dilatation in solid samples under well-defined thermal conditions. The oven can be thermally stabilized to better than 0.1 mK over a temperature range of −60 to 150 °C using a two-stage control strategy. Coarse control is obtained by heat exchange with a circulating thermal fluid, whereas the fine regulation is based on a solid-state heat pump—a Peltier element, acting as heating and cooling source. The bidirectional action of the Peltier element permits the sample block to be controlled at the average temperature of the surroundings, thus making an essentially adiabatic system with a minimum of thermal gradients in the sample block. The dilatometer cell integrated in the oven assembly is of the parallel plate air capacitor type, and the apparatus has been successfully used with a sensitivity of 0.07 A(ring). Our system is well suited for measurements near structural phase transitions with a relative resolution of Δt=(T−Tc)/Tc=2×10−7 in temperature and ΔL/L=1×10−9 in strain.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.1138623

    Articles: DFG German National Licenses
  16. 16
    Riise, A. B. ; Johansen, T. H. ; Bratsberg, H. ; Yang, Z. J.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The dynamic response of the levitation force between a permanent magnet and a bulk YBCO superconductor when subjected to a sudden motion-induced step in the magnetic field has been measured. It is found that the levitation force relaxes logarithmically with time. Assuming that force and magnetization behave similarly, the rate of decay can be interpreted in terms of a thermally activated flux creep with a depinning activation energy of U0=0.20 eV. A replot of previously published results for melt-quenched YBCO also demonstrates that also in this material the force relaxation is characterized by a logarithmic decay.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.107034

    Articles: DFG German National Licenses
  17. 17
    Gaevski, M. E. ; Johansen, T. H. ; Galperin, Yu. ; Bratsberg, H.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1997
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Burning of superconducting thin film bridges by large transport currents (up to densities of 2×107 A/cm2) is investigated by magneto-optical imaging of flux distribution and low-temperature scanning electron microscopy providing Tc maps. It is shown that the destruction is preceded by significant penetration of magnetic field inside a weak-pinning region. In bridges containing extended defects magneto-optic investigation is sufficient to locate the incipient burning region. In high-quality bridges free from such defects only a combination of the two techniques will allow prediction of the place of fatal destruction. © 1997 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.120272

    Articles: DFG German National Licenses
  18. 18
    Baziljevich, M. ; Johansen, T. H. ; Bratsberg, H. ; Shen, Y. ; Vase, P.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1996
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Slits patterned into a YBa2Cu3O7−δ thin film were observed to obstruct Meissner sheet currents leading to an imbalance in the local Meissner screening properties. The new phenomenon was studied with magneto-optic imaging where twin lobes of opposite flux polarity were seen to form near the slits and inside the Meissner region. The lobe closest to the sample edge is always polarized opposite to the applied field. At weak fields, the anomalous flux generation is reversible. At higher fields, but still sufficiently small to keep the vortex penetration front away from the slits, the anomalous current starts nucleating flux lines which become trapped when the field is removed. © 1996 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.117216

    Articles: DFG German National Licenses
  19. 19
    Johansen, T. H. ; Bratsberg, H. ; Yang, Z. ; Helgesen, G. ; Skjeltorp, A. T.

    [S.l.] : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    Based on a simple mechanical pendulum design, we developed a sensor for measurement of the horizontal force on a permanent magnet placed at any distance above a high-Tc superconductor. In this fully computerized system, which employs closed-loop feedback control, the lateral interaction with its restoring and hysteretic nature can be studied under conditions of constant vertical separation. Results are presented for the case of a small Nd-Fe-B magnet at a distance of 1 mm above a large planar disk of a YBa2Cu3Ox superconductor.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.1141508

    Articles: DFG German National Licenses
  20. 20
    Johansen, T. H. ; Bratsberg, H.

    [S.l.] : American Institute of Physics (AIP)
    Published 1993
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A quantitative first-order theory for the lateral force between a permanent magnet and a type-II superconductor is presented. The levitation configuration discussed is that of a long rectangular bar magnet placed above a finite-sized rectangular superconductor. The central issues of stability and stiffness (elastic spring constant) associated with lateral vibrations are discussed. Closed-form expressions for both the force and stiffness are derived, thus bringing out clearly the significance of both geometrical dimensions and the magnetic response of the superconductor. It is assumed that the superconductor is either a sintered granular or consists of grains embedded in a nonactive matrix (composite) so that only intragranular shielding currents are important. The predicted behavior as a function of levitation height agrees very well with existing experimental results.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.354450

    Articles: DFG German National Licenses