Search Results - (Author, Cooperation:A. Zehnder)

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  1. 1
    Staff View
    Publication Date:
    2012-12-04
    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:
    Base Sequence ; Cell Differentiation/*genetics ; Cells, Cultured ; Cytoskeletal Proteins/metabolism ; Epidermis/*cytology/*metabolism ; Gene Expression Regulation ; High-Throughput Screening Assays ; Humans ; Keratinocytes ; Mutation ; Nucleotide Motifs/genetics ; Protein Binding ; RNA Stability/genetics ; RNA, Long Noncoding/*genetics/*metabolism ; RNA, Messenger/genetics/metabolism ; RNA-Binding Proteins/metabolism ; Skin Diseases/genetics
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Scherschel, M. A. ; Hagen, C. W. ; Jaggi, A. ; Maier, Th. ; Zehnder, A. ; Zhao, S. P. ; Ott, H. R.

    [S.l.] : American Institute of Physics (AIP)
    Published 1995
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The feasibility of superconducting strips as position-sensitive detectors for α particles was investigated. For this purpose films have been prepared of different materials and dimensions using standard evaporation and laser ablation in an UHV system. Films were patterned into strips and current-biased strips were irradiated with 5.5 MeV α particles. The energy deposited by the particle in the strip creates a normal-conducting region, which in turn causes a voltage drop. The time evolution of the voltage drop across the strip as a function of bath temperature and bias current has been investigated. Information about the site of the strip hit by the α particle was obtained from monitoring the propagating normal-conducting zones. A lateral position sensitivity of ±30 μm for a tantalum strip detector has been achieved. The propagation of normal-state zones in the strip cannot provide information on the energy of the particle. A model describing the time evolution of a normal-conducting zone in a current-biased superconducting strip was used to test and interpret the experimental results and allows one to estimate the thermal conductivity of the strip material and the heat transfer from the strip into the substrate. © 1995 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  3. 3
    Twerenbold, D. ; Zehnder, A.

    [S.l.] : American Institute of Physics (AIP)
    Published 1987
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    In a superconducting detector, the energy resolution is expected to be superior than in a semiconductor detector, owing to the thousand times smaller energy gap Δ. The performance of Sn/Sn-oxide/Sn tunneling junctions (operated in the Giaever mode at T=0.32 K) exposed to 6-keV x-ray photons of a 55Fe source is presented. The best energy resolution observed is 67 eV (FWHM). Extrapolating to vanishing electronic noise, an intrinsic resolution of 0.7% (FWHM) is obtained. This is an order of magnitude worse than expected from the statistics of the 2.5×106 primary electron charges produced, and is believed to be due to geometrical effects in the films. The energy response of the detector is nonlinear, owing to the self-recombination of the free charge carriers. At a fixed bias voltage, the pulses generated in either film of the junction were observed to have the same sign. If the junctions are evaporated onto a silicon substrate, most of the pulses originate, via phonon backscattering, from x-ray photons interacting in the substrate. Quasiparticle diffusion is essential in explaining the observed data.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  4. 4
    Zalalutdinov, M. ; Olkhovets, A. ; Zehnder, A. ; Ilic, B. ; Czaplewski, D. ; Craighead, H. G. ; Parpia, J. M.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 2001
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Micromechanical oscillators in the rf range were fabricated in the form of silicon discs supported by a SiO2 pillar at the disk center. A low-power laser beam, (Plaser∼100 μW), focused at the periphery of the disk, causes a significant change of the effective spring constant producing a frequency shift, Δf(Δf/f∼10−4). The high quality factor, Q, of the disk oscillator (Q∼104) allows us to realize parametric amplification of the disk's vibrations through a double frequency modulation of the laser power. An amplitude gain of up to 30 was demonstrated, with further increase limited by nonlinear behavior and self-generation. Phase dependence, inherent in degenerate parametric amplification, was also observed. Using this technique, the sensitivity of detection of a small force is greatly enhanced. © 2001 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  5. 5
    Zalalutdinov, M. ; Zehnder, A. ; Olkhovets, A. ; Turner, S. ; Sekaric, L. ; Ilic, B. ; Czaplewski, D. ; Parpia, J. M. ; Craighead, H. G.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 2001
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Self-generated vibration of a disk-shaped, single-crystal silicon micromechanical oscillator was observed when the power of a continuous wave laser, focused on the periphery of the disk exceeded a threshold of a few hundred μW. With the laser power set to just below the self-generation threshold, the quality factor for driven oscillations increases by an order of magnitude from Q=10 000 to Qenh=110 000. Laser heating-induced thermal stress modulates the effective spring constant via the motion of the disk within the interference pattern of incident and reflected laser beams and provides a mechanism for parametric amplification and self-excitation. Light sources of different wavelengths facilitate both amplification and damping. © 2001 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  6. 6
    Zalalutdinov, M. ; Ilic, B. ; Czaplewski, D. ; Zehnder, A. ; Craighead, H. G. ; Parpia, J. M.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 2000
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    An experimental method, employing a scanning tunneling microscope (STM) as an actuator and a scanning electron microscope (SEM) as a motion detector, was developed to study microelectromechanical systems (MEMS) and has been applied to study microfabricated cantilever beams. Vibrations actuated by an ac voltage applied to the piezodrive are transferred to the sample by the STM tip, which also provides a constraint at the drive location, altering the fundamental mode of the oscillation. A continuous change in the resonant frequency of the cantilever is achieved by varying the position of the STM tip. In contrast to the few percent tunability previously demonstrated for MEMS oscillators, we have varied the cantilever frequency over a 300% range. © 2000 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  7. 7
    Sentchilo, V. ; Zehnder, A. J. B. ; Van Der Meer, J. R.

    Oxford, UK : Blackwell Science Ltd
    Published 2003
    Staff View
    ISSN:
    1365-2958
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Biology
    Medicine
    Notes:
    The clc genomic island is a 105 kb integrative and conjugative element (ICE) in Pseudomonas sp. strain B13, which encodes metabolism of 3-chlorocatechol. The clc island is integrated in a tRNAGly gene, but can excise and form a circular intermediate in which both ends are connected. The integrase gene (intB13) of the clc genomic island is located at the right end, 202 bp from the junction site facing inwards. Fragments upstream of intB13 in the circular form and in the integrated form were fused to a promoterless gfp gene for Green Fluorescent Protein and introduced in monocopy onto the chromosome of strain B13. Quantitative GFP fluorescence measurements in individual cells of the different B13-derivatives revealed that the circular form fragment contained a strong constitutive promoter (Pcirc) driving intB13 expression in all cells. By using primer extension Pcirc could be mapped near the left end of the clc element and Pcirc can therefore only control intB13 expression when left and right ends are connected as in the circular form. Expression from intB13 upstream fragments from the integrated clc element was weaker than that from Pcirc and only occurred in maximally 15% of individual cells in a culture. A promoter (Pint) could be roughly mapped in this region by using reverse-transcription PCR and by successively shortening the fragment from the 5′ end. Transposon mutants in cloned left end sequences of the clc element were selected which had lost the activation potential on the Pint promoter and those which resulted in overexpression of GFP from Pint. The DNA sequence of the region of the transposon insertions pointed to a relatively well conserved area among various other genomic islands. The activator mutants mapped in an open reading frame (ORF) encoding a 175 amino acid protein without any significant similarity to functionally characterized proteins in the databases.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  8. 8
    Staff View
    ISSN:
    0921-4526
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  9. 9
    Rothmund, W. ; Hagen, C.W. ; Zehnder, A.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0921-4526
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  10. 10
    Staff View
    ISSN:
    0921-4526
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  11. 11
    Staff View
    ISSN:
    0921-4534
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  12. 12
    Staff View
    ISSN:
    0921-4534
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  13. 13
    Staff View
    ISSN:
    0375-9474
    Keywords:
    Nuclear moments
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  14. 14
    Staff View
    ISSN:
    0375-9474
    Keywords:
    Nuclear Reactions
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  15. 15
    Zehnder, A.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0370-2693
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  16. 16
  17. 17
    Staff View
    ISSN:
    0375-9474
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  18. 18
    Ludlam, T. ; Zehnder, A.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0375-9474
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  19. 19
    Staff View
    ISSN:
    0375-9474
    Keywords:
    Muonic atoms
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  20. 20
    Staff View
    ISSN:
    0375-9474
    Keywords:
    Atomic physics ; Nuclear moments
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses