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  • 1
    Electronic Resource
    Electronic Resource
    Exchange-biased magnetic tunnel junctions fabricated with in situ natural oxidation (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 5261-5263 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Exchange-biased magnetic tunnel junctions with a Ta/NiFe/FeMn/NiFe/Al–oxide/NiFe/Ta structure have been fabricated. The tunnel barrier was formed by the in situ natural oxidation of an Al metal layer under controlled oxygen pressure. Photolithography and ion milling were used to pattern the multilayer into junction structures of 2×2 μm2–20×20 μm2 dimensions. Magnetoresistance (MR) curves show spin-valve-like characteristics, in which an antiparallel configuration of magnetizations in both ferromagnetic layers is observed between 50 and 240 Oe, and the hysteresis loops for both the free and pinned layers exhibit sufficient separation. An evaluation of the MR curves shows the exchange-bias field to be 340 Oe and coercivity levels in the free layer to become as low as 13 Oe. At room temperature normalized junction resistance is 2×10−5 Ω cm2, with MR ratios still being maintained at 13%. This resistance value is much lower than previously reported values for junctions produced either with plasma oxidation or thermal oxidation in air. Maximum variation in junction resistance is only ±5% for 10×10 μm2 junctions over a 2 in. wafer. The MR ratio decreases by half when the bias voltage is raised from 0 to 440 mV, approximately the same ratio of decrease as has been previously reported for other successful junctions. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369960
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  • 2
    Electronic Resource
    Electronic Resource
    Interface structures and magnetoresistance in magnetic tunnel junctions (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 5807-5809 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The interface structures of magnetic tunnel junctions were studied using x-ray photoelectron spectroscopy (XPS). The structures were correlated with magnetoresistance (MR) characteristics. For MR measurements, Fe(50 nm)/AlOx/CoFe(30 nm) junctions with an in situ naturally oxidized Al tunnel barrier were fabricated. The thickness of the Al layer, an important parameter in MR characteristics, was varied from 0 to 5 nm. MR curves showed that the largest MR ratio occurred when the Al layers were 2–3 nm in thickness. XPS analysis showed that an Al layer greater than 1 nm thick covers the entire surface of the Fe underlayer. However, if the Al layer is more than 1 nm thick, the unoxidized Al remaining after the oxidation process increases as the thickness is increased. For Al layers that are greater than 3 nm thick, the MR ratio is strongly affected by unoxidized Al, probably due to the decrease in spin polarization at the surface of an Fe/Al electrode. On the other hand, the hysteresis loops indicate that the difference in coercive force between Fe and CoFe layers reduces with decreasing Al thickness for Al layers less than 2.5 nm thick. This means that the antiparallel direction of magnetization in the two layers becomes incomplete due to the gradual increase of the ferromagnetic coupling between them. As a result, the MR ratio decreases, although a 1-nm-thick Al layer seems to be enough to cover the Fe surface. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369926
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  • 3
    Electronic Resource
    Electronic Resource
    Near-field optical fiber probe optimized for illumination–collection hybrid mode operation (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 2773-2775 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The structure of a near-field probe was optimized for illumination-collection hybrid mode (I–C mode) operation. We developed a highly sensitive probe with a sharp-edged aperture and a double-tapered structure fabricated by a chemical etching technique. Through measurement of the photoluminescence (PL, λ=1 μm) image of single quantum dots, the performance of many versions of the probe with different aperture diameters, ranging from 80 to 500 nm, was systematically evaluated. In addition to the throughput and spatial resolution, the absolute value of the PL collection efficiency of the probe in (I–C mode) was also estimated for the first time. A collection efficiency several times greater than that of an objective lens with a numerical aperture of 0.8 was achieved with high spatial resolution in the 130–200 nm (λ/8–λ/5) range. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123307
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  • 4
    Electronic Resource
    Electronic Resource
    ALTERATION IN THE RELEASE OF ENDOTHELIUM-DERIVED RELAXING FACTORS BY α-ADRENOCEPTOR STIMULATION IN THE AORTA OF STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical and experimental pharmacology and physiology 22 (1995), S. 0 
    Details
    ISSN: 1440-1681
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: 1. Endothelium-dependent relaxation by a-adrenoceptor agonists was examined in the thoracic aorta from normoten-sive Wistar-Kyoto (WKY) rats and stroke-prone spontaneously hypertensive rats (SHRSP).2. In ring preparations from both strains, noradrenaline-induced contraction was increased by L-nitro arginine (L-NNA), a NO synthesis inhibitor.3. L-NNA increased the contraction induced by phenyl-ephrine, an α1-adrenoceptor agonist. UK-14304 and clonidine, α2-adrenoceptor agonists, did not contract the preparations with intact endothelium. However, these agents contracted preparations when NO synthesis was inhibited.4. In a precontracted preparation, clonidine and UK-14304 induced relaxations. The relaxations in SHRSP aorta were smaller than those in WKY aorta.5. These results indicate that a-agonists release NO from endothelium in WKY and SHRSP aorta. The mechanism related to NO release by α2-adrenoceptor agonist is impaired in SHRSP aorta.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1440-1681.1995.tb02856.x
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  • 5
    Electronic Resource
    Electronic Resource
    Effect of oxygen on the corrosion of dental amalgam (1985)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of oral rehabilitation 12 (1985), S. 0 
    Details
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The anodic and cathodic polarization of five dental amalgams were determined as a function of oxygen concentration in Ringer's solution and artificial saliva. The results indicate an anodic polarization behaviour dependent on Cl ion concentration and a corrosion potential determined primarily by oxygen concentration. At high oxygen concentrations the corrosion rates of traditional and copper enriched amalgams were equivalent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2842.1985.tb00629.x
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  • 6
    Electronic Resource
    Electronic Resource
    Polyribosome metabolism, growth and water status in the growing tissues of osmotically stressed plant seedlings (1985)
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 64 (1985), S. 0 
    Details
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Relationships between growth of osmotically stressed intact seedlings and polyribosome levels and water status of growing tissues were examined. Sudden exposure of barley (Hordeum vulgare L. cv. Arivat) roots to a solution of −0.8 MPa polyethylene glycol caused leaf growth to stop almost immedately, but growth resumed at a much lower rate after 0.5–1 h. In the growing region of leaves, the polyribosome: total ribosome ratio of free (non-membrane-bound) ribosomes was significantly reduced after 15 min stress, but a decrease in the large polyribosome:total polyribosome ratio occurred only after 1–2 h. Membrane-bound and free polyribosome levels both decreased to 70% of unstressed control values after 4 h stress. Recovery of total polyribosomes occurred within 1 h after relief of 4 h stress, but required 3 h after relief of 24 h stress. Stress detectably reduced the water potential and osmotic potential of growing tissue within 0.5–1.0 h, and osmotic adjustment continued for up to 10 h. Recovery of water status was incomplete after 1 h relief of a 4 h stress. In contrast, expanded blade tissues of stressed plants underwent minor changes in water status and slow decreases in polyribosomes levels. These results confirm that growing tissues of barley leaves are selectively responsive to stress, and suggest that changes in growth, water status and polyribosome levels may be initiated by the same signal. Measurements of seedling growth, polyribosome levels and water status of growing tissues of barley and wheat (Triticum aestivum L. cv. Zaragoza) leaves, etiolated pea (Pisum sativum L. cv. Alaska) epicotyl and etiolated squash (Cucurbita pepo L. cv. Elite) hypocotyl stressed with polyethylene glycol solutions of −0.3 to −0.8 MPa for 12 h or more showed that polyribosome levels were highly correlated with seedling growth rate as well as with tissue water and osmotic potentials, while turgor remained unchanged. These results suggest that long-term growth of osmotically stressed plants may be limited by a reduced capacity for protein synthesis in growing tissues and is not dictated by turgor loss.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1399-3054.1985.tb01218.x
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  • 7
    Electronic Resource
    Electronic Resource
    Revision surgery after triple-cup arthroplasty (1999)
    Springer
    Archives of orthopaedic and trauma surgery 119 (1999), S. 380-383 
    Details
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Although various operative procedures have been applied for advanced or terminal osteoarthritis of the hip joints in relatively young patients, the long-term results are controversial. Since 1974, we have performed the triple-cup arthroplasty developed by Aoki in 110 patients who were comparatively young. The triple-cup assembly is composed of stainless-steel outer and inner cups between which a high density polyethylene cup is incorporated, so that there are basically four mobile surfaces, but the major movement is actually taking place between the outer cup and the plastic cup [8]. We have sometimes encountered migration of the cups, which caused hip joint pain and decreased the range of motion. Revision surgery was required for 25 hip joints in 21 patients (23%). The acetabulum was very thin in almost all cases, so that reaming of the cavity had to be restricted to the minimum possible. The femoral head in the cup was often covered with a layer of fibrous tissue. We could utilize the femoral head as a bone graft, even though the residual volume of bone varied in each case. The result of revision surgeries after the triple-cup arthroplasty was good clinically and radiographically at last follow-up.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004020050433
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  • 8
    Electronic Resource
    Electronic Resource
    Postbuckling behavior of circular cylindrical shells under torsion (1976)
    Springer
    Archive of applied mechanics 45 (1976), S. 79-89 
    Details
    ISSN: 1432-0681
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Übersicht Durch Anwendung des Verfahrens von Galerkin auf die Donnellschen Grundgleichungen werden praktisch genaue Lösungen für das Nachbeulverhalten von eingespannten Kreiszylinderschalen gewonnen, die einer Torsion unterworfen sind. Über detaillierte Rechnungen für einen weiten Bereich von Schalengeometrien wird geklärt, wie Verdrehung, Stauchung und Nachbeulverformung mit dem gegebenen Torsionsmoment zusammenhängen. Die Ergebnisse stimmen mit experimentell ermittelten Werten gut überein.
    Notes: Summary Applying the Galerkin procedure to the Donnell basic equations, fairly accurate solutions are obtained for the postbuckling behavior of clamped circular cylindrical shells subjected to torsion. Through detailed calculations, main postbuckling characteristics, i.e., connections of the angle of twist, axial shortening and deflection with applied torque, are clarified for a wide range of shell geometrics. The results here obtained are ascertained to be in good agreement with the corresponding experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00534361
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  • 9
    Electronic Resource
    Electronic Resource
    Correlation between culture medium pH, extracellular proteinase activity, and cell growth of Candida albicans in insoluble stratum corneum-supplemented media (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 342-345 
    Details
    ISSN: 1432-069X
    Keywords: Candida albicans ; Extracellular proteinase ; Medium pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Candida albicans produces a major extracellular proteinase whose activities are observed only in weakly acidic pH. However, in affected lesions, a variety of pH conditions exist, including neutral pH. To verify the pathological importance of the extracellular proteinase, the correlation between culture medium pH, extracellular proteinase activity, and cell growth of C. albicans was followed for 3 weeks with unbuffered and insoluble stratum corneum-supplemented liquid media. Each medium pH, initially adjusted within a range of pH 3–7 by the addition of sodium hydroxide or hydrochloric acid solution, was acidified, and a subsequent high proteolytic activity and rapid fungal growth were observed. After full fungal growth, neutralization of each medium to pH 7 and reduction of proteinase activity occurred. Results from a glucose addition experiment suggest that acidification of each medium was produced by the acid formation from glucose and neutralization by the exhaustion of glucose and increase of ammonia from denatured stratum corneum. These data suggest that extracellular proteinase from C. albicans could act as a virulence factor under a wide range of pH conditions by the acidification of the environmental pH close to the organism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00412979
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  • 10
    Electronic Resource
    Electronic Resource
    Extracellular proteinase production and the pathogenicity of Nocardiae (1989)
    Springer
    Archives of dermatological research 281 (1989), S. 78-80 
    Details
    ISSN: 1432-069X
    Keywords: Extracellular proteinase ; Nocardiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00424279
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