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  • 2000-2004  (4)
  • 1985-1989  (15)
  • 1980-1984  (8)
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 5428-5430 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mono- and polycrystalline Ni films, ranging in thickness from 19 to 382 nm, have been produced by vacuum deposition on (001) monocrystalline Ag/NaCl and on glass substrates, respectively. Subsequently, saturation magnetization Ms, magnetogyric factor γ/2π, and effective uniaxial anisotropy Hk were measured by a combination of vibrating sample magnetometer and ferromagnetic resonance (FMR), and corresponding internal stress σ was measured by a levered optical beam reflection technique. In addition, the microstructure of both mono- and polycrystalline films has been characterized by conventional and cross-section transmission electron microscopy. Saturation magnetization can be interpreted by the presence of a magnetic dead layer of about 9 nm and a constant value of 434 emu/cm3, thereafter. Results from FMR can be described by contributions from shape and stress-induced anisotropy. Corresponding values of σ, as computed from Hk, are in satisfactory agreement with values measured by the optical beam reflection technique and yield values of about 1010 dyn/cm2; σ generally decreases with increasing film thickness and annealing time and temperature. Finally, monocrystalline films are characterized by a single FMR peak; polycrystalline films thicker than about 200 nm are characterized by multiple peaks. Occurrence of these multiple peaks is attributed to variation in the effective magnetoelastic constant as a result of a change from equiaxed to columnar grain morphology.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 61 (1987), S. 3804-3806 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin films of cobalt, nickel, and their alloys have been produced on glass substrates by thermal evaporation at oblique angles of incidence α, measured with respect to the substrate normal, ranging from 20° to 78°. Resultant films are characterized by a columnar grain structure inclined toward the source by an angle β, also measured with respect to the substrate normal, such that 2 tan β∼tan α. For α〉60°, the columnar grains assume a rodlike morphology surrounded by voids, whereas for α〈60°, these grains assume a platelike morphology, also inclined toward the source and separated by voids. The void size, defined by spacing between adjacent rods or plates, increases with increasing values of α. Moreover, for α〉60°, the easy axis of magnetization is oriented in the vapor plane, defined by the plane parallel to both the direction of incident flux and substrate normal, whereas, for α〈60°, this axis is oriented perpendicular to the vapor plane. Accordingly, the easy axis of magnetization is oriented parallel to the rodlike morphology when α〉60°, and parallel to the platelike morphology (and in the plane of the film), when α〈60°. Finally, magnetic coercivity increases rapidly at the critical angle of 60°, as transition from platelike to rodlike morphology occurs.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 59 (1986), S. 1147-1155 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mechanisms of interdiffusion in copper/nickel thin-film couples have been investigated in the temperature interval 573–777 K by in situ measurement of contact resistance, Auger depth profiling (ADP), and transmission electron microscopy. Correlation between evolution of contact resistance and measured Auger concentration profiles has been established and mechanisms incorporating rapid grain boundary diffusion, followed by defect-assisted diffusion into grain interiors (Type B kinetics), are proposed to explain the accelerated reactions observed. A modified Whipple model and two independent methods, based on ADP and contact resistance measurements, are used to calculate grain boundary and intragranular diffusion coefficients, respectively. The calculated grain boundary diffusion coefficient is (0.82 cm2/s) exp(−1.48eV/kT) for nickel in copper, and approximately 4×10−13 cm2/s for copper in nickel at 673 K. An average intragranular diffusion coefficient for nickel in copper is determined to be (2.6×10−6 cm2/s) exp(−1.38 eV/kT) by both methods, whereas ADP data yield a corresponding value of (5.2×10−8 cm2/s) exp(−1.51eV/kT) for copper in nickel. It is concluded that characterization of chemical composition and microstructure, combined with in situ measurement of concomitant electrical properties, provides a reliable description of interdiffusion mechanisms in this system.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 62 (1987), S. 1245-1250 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Circular gold dots, measuring about 200 μm in diameter and either 150 or 300 nm in thickness, have been produced on {100}, {110}, and {111} substrates of indium phosphide by a combination of vapor deposition and photolithographic processing, annealed at temperatures ranging from 420–460 °C, and subsequently examined by optical microscopy. During annealing, a reaction product, bounded by well-defined crystallographic planes of the substrate, forms, expands parabolically with annealing time, and eventually saturates due to the limited supply of gold. Generally, reactions proceed at least three times faster at {100} and {110} planes than at {111}In planes, in which reactions proceed about three times faster than at {111}P planes. Analysis of concomitant reaction kinetics yields an activation energy of 8.6±3.0 eV for reactions at {111}In planes. Results are interpreted in terms of a preferential interfacial reaction at {111}In planes, which is controlled by solid-state diffusion and eventual escape of phosphorus.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Physiology 51 (1989), S. 845-856 
    ISSN: 0066-4278
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Medicine , Biology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 57 (1985), S. 2155-2160 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Amorphization produced by ion implantation and subsequent crystallization produced by thermal processing have been investigated in films of (SmYGdTm)3Ga0.4Fe4.6O12 garnet by transmission electron microscopy, incorporating a special cross-sectioning technique. These films were produced by liquid-phase epitaxy on {111} garnet substrates and subsequently implanted with ions of deuterium at 60 keV and doses ranging from 0.50 to 4.5×1016 D+2/cm2 and ions of oxygen at 110 keV and doses ranging from 0.95 to 8.6×1014 O+/cm2. The amorphization process evolves in four separate stages: (1) an implanted (crystalline) band, delineated by the implantion strain profile, forms at doses of about 0.50×1016 D+2/cm2/ and 0.95 O+/cm2, (2) isolated amorphous regions of about 10 nm in diameter form at doses of about 1.0×1016 D+2/cm2 and 1.9×1014 O+/cm2, (3) the amorphous regions merge to form a continuous band below the implanted surface at doses of about 3.0×1016 D+2/cm2 and 5.7×1014 O+/cm2, and (4) this band expands to the implanted surface at larger doses. Amorphization is caused by implantation with oxygen, but prior implantation with deuterium sensitizes the lattice by increasing the strain. The crystallization process evolves in three separate stages: (1) small crystallites, about 10 nm in size, form throughout the entire amorphous band after annealing for 10 min at 350 °C, (2) larger crystallites nucleate and grow from the implanted surface and amorphous/crystalline interface after annealing for 10 min at 450 °C, and (3) these crystallites grow in size until they merge to form a continuous polycrystalline layer. Some epitaxial regrowth of the monocrystalline into the amorphous region is also observed. Details of these processes are interpreted in terms of atomic displacement mechanisms and compared with corresponding changes of certain magnetic properties.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1365-2826
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The neuroendocrine Type 1 Dahlgren cells of the caudal neurosecretory system of the flounder display characteristic bursting activity, which may increase secretion efficiency. The firing activity pattern in these cells was voltage-dependent; when progressively depolarized, cells moved from silent (approximately −70 mV), through bursting and phasic to tonic firing (〈 −65 mV). Brief (10 s) evoked bursts of spikes were followed by a slow after-depolarization (ADP; amplitude up to 10 mV, duration 10–200 s), which was also voltage-dependent and could trigger a prolonged burst. The ADP was significantly reduced in the absence of external Ca2+ ions or the presence of the L-type Ca2+ channel blocker, nifedipine. BayK 8644 (which increases L-type channel open times) significantly increased ADP duration, whereas the Ca2+-activated nonselective cation channel blocker, flufenamic acid, had no effect. Pharmacological blockade of Ca2+-activated K+ channels, using apamin and charybdotoxin, increased the duration of both ADP and evoked bursts. However, action potential waveform was unaffected by either apamin/charybdotoxin, nifedipine, BayK 8644 or removal of external Ca2+. The short duration (approximately 100 ms), hyperpolarization-activated, postspike depolarizing afterpotentials (DAP), were significantly reduced by nifedipine. We propose that long duration ADPs underlie bursts and that short duration DAPs play a role in modulation of spike frequency.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background:  Especially in childhood, sublingual immunotherapy (SLIT) could offer advantages over subcutaneous therapy. However, limited data on its efficacy is available.Methods:  In four German centres 97 children (age 3–14 years) with allergic rhinoconjunctivitis to grass pollen were enrolled in a prospective, double-blind trial comparing SLIT (Pangramin SLIT®; ALK-SCHERAX, 0.5 μg major allergens, three times per week, 32 months) with placebo. Primary endpoint was a multiple symptom-medication score for changes in seasonal diary entries between the first and third year of the study (SLIT n = 39; placebo n = 38).Results:  The multiple symptom-medication score was significantly reduced by SLIT to 77.3% of the placebo group (P = 0.0498). The subsequent analysis of the single endpoints did not reveal significant differences for symptom scores in favour of SLIT (85.1% of placebo group; P = 0.22). However, the medication score improved significantly (67.1% of placebo group; P = 0.0025). Furthermore, secondary endpoints assessing in vivo immune responses did not differ significantly between the groups. However, retrospective analysis showed some inhomogeneity for clinical and in vitro parameters at the beginning of the study. Allergic side effects with possible relation to the study drug were reported in both groups (SLIT 49%, placebo 27%, P = 0.026).Conclusion:  Our study indicates that SLIT had a positive effect on the reduction of a multiple symptom-medication score, mainly by significantly reducing rescue medication use, but had no significant effect on symptoms alone in children with rhinoconjunctivitis to grass pollen compared with a placebo.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 66 (1988), S. 241-245 
    ISSN: 1432-1440
    Keywords: Erythropoietin ; Stability ; Radioimmunoassay ; Polycythemic mouse bioassay ; Recombinant DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Radioimmunoassays for erythropoietin are limited so far to a few specialized laboratories and this requires transport and storage of samples. We therefore tested the stability of immunoreactive erythropoietin in serum and plasma samples obtained from a uremic and a nonuremic anemic patient. No significant change in the concentration of immunoreactive erythropoietin was found in either serum or plasma samples for up to 14 days of storage. This type of stability was observed no matter whether the samples were stored at room temperature, 4° C, or −20° C. There was no difference between the estimates of erythropoietin in serum and heparinized plasma. Validity of the radioimmunoassay used in this study was demonstrated by parallelism of dilution curves of test specimens and the 2nd International Reference Preparation for erythropoietin and by a close correlation between the immunoreactivity and the bioactivity of the hormone, as assessed in the same samples by the exhypoxic polycythemic mouse bioassay. In conclusion the data obtained clearly indicate that the necessity of storage and transport of clinical samples does not limit the practicability of the radioimmunoassay for erythropoietin.
    Type of Medium: Electronic Resource
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