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  • 1
    Electronic Resource
    Electronic Resource
    Activation of Zn and Cd acceptors in InP grown by metalorganic vapor phase epitaxy (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 2411-2413 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated the activation by post-deposition annealing of Zn and Cd acceptors incorporated in InP during epitaxial growth using metalorganic vapor phase epitaxy. Growth was carried out at 20 mbar and atmospheric pressure for Zn- and Cd-doped samples, respectively, using TMI, PH3, DEZn, and DMCd as sources. Post-epitaxial annealing in a N2 atmosphere at temperatures in the range of 370–470 °C leads to complete activation of the acceptors. This process is strongly temperature dependent and a distinct effect of a GaInAs overlayer was observed. The activation energy is the same for Zn- and Cd-doped samples. It is suggested that the diffusion of vacancies plays a determining role in activating the dopant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.101091
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  • 2
    Electronic Resource
    Electronic Resource
    Structure of electron-cyclotron ordinary mode damping (1989)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 1 (1989), S. 1937-1939 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The ordinary mode damping near the electron-cyclotron frequency is investigated using the relativistic dispersion relation. It is shown that the Doppler splitting of the absorption spectrum claimed by Arunasalam et al. [Phys. Rev. A 36, 3909 (1987); 37, 2063 (1988)] is an erroneous result obtained from an oversimplified dispersion relation and assuming an infinite speed of light in the resonance condition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.859113
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  • 3
    Electronic Resource
    Electronic Resource
    Properties of the two-dimensional electron gas in modulation-doped GaInAs(P)/InP structures grown by low-pressure metalorganic vapor-phase epitaxy (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 697-703 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This paper is concerned with the characteristics of the two-dimensional electron gas (2DEG) at modulation-doped GaInAs/InP and GaInAsP/InP heterojunctions and GaInAs/InP single-quantum-well structures grown by low-pressure metalorganic vapor-phase epitaxy (LP-MOVPE) at 20 hPa. Using trimethyl-In, trimethyl-Ga, AsH3, and PH3 as source materials, this process permits the deposition of very uniform films with abrupt interfaces and doping profiles. We give the first detailed analysis of modulation-doped structures by classical Hall effect, Shubnikov–de Haas, and quantum Hall-effect measurements. Study of the scattering mechanisms of the 2DEG in modulation-doped GaInAs/InP and GaInAsP/InP structures reveals a small interface roughness and a low impurity content at the interfaces. Electron mobilities at 4.2 K up to 189 000 cm2/V s for a GaInAs/InP and 72 000 cm2/V s for a GaInAsP/InP heterojunction as well as values as high as 170 000 cm2/V s for a GaInAs/InP quantum well structure demonstrate the excellent control of the growth process and the quality of the material attainable by LP-MOVPE.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.343540
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  • 4
    Electronic Resource
    Electronic Resource
    Immature rat epididymal epithelial cells grown in static primary monolayer culture on permeable supports (1989)
    Springer
    Cell & tissue research 256 (1989), S. 567-572 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Monolayer culture ; Directed secretion ; Phosphatases ; Glucosaminidase ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A cell culture system is characterised for monolayers of immature rat epididymal epithelial cells grown on permeable supports. Cover of the filters was achieved by days 4–5 and was maintained for 9–12 days. The secretion of acid phosphatase (ACP), alkaline phosphatase (AKP) and N-acetylglucosaminidase (NAG) into apical and basal compartments of culture chambers was monitored with time in culture for cells from the proximal and distal epididymis of 37-day-old animals. There was independent secretion of the three enzymes: secretion of NAG and AKP was mainly apical, that of ACP basal; daily secretion of ACP and AKP was constant throughout culture, that of NAG declined; there was greater secretion of NAG and AKP by cells from the proximal than the distal region. The initial high apical secretion of NAG is thought to reflect loss of enzyme from unattached cells, whereas the later AKP secretion is truly directional. Secretion was not influenced by the enzymes used in cell preparation. The cytotoxic agent Thimerosal inhibited secretion of all enzymes when placed beneath the cultures, indicating that secretion depended on viable cells, but initially stimulated release of AKP when applied above the cells possibly reflecting release from the cell membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225605
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  • 5
    Electronic Resource
    Electronic Resource
    Immature rat epididymal epithelial cells grown in static primary monolayer culture on permeable supports (1989)
    Springer
    Cell & tissue research 256 (1989), S. 573-580 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Epithelium ; Monolayer culture ; Histochemistry ; Electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary N-acetylglucosaminidase (NAG), acid phosphatase (ACP) and alkaline phosphatase (AKP) were localised histochemically in fixed cells from the 37-day-old rat epididymis grown in static monolayer culture for 2–8 days. ACP and NAG were cytosolic enzymes found in perinuclear positions, whereas staining of AKP was consistent with a membranous position. These enzymes were also examined in frozen tissue sections of the epididymis, from rats of the equivalent age, where NAG had intense activity in both supra- and infra-nuclear cytoplasm and ACP was more active apically. For the first time AKP was localised along basolateral membranes of the epithelium and in the lumen of the mid-caput region. The monolayer in culture was of principal cells only and they maintained their polarity and ultrastructural characteristics, but the height of the cells was reduced compared to that obtained in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225606
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  • 6
    Electronic Resource
    Electronic Resource
    Excitation-contraction coupling in voltage-clamped cardiac myocytes (1989)
    Springer
    Basic research in cardiology 84 (1989), S. 136-148 
    Details
    ISSN: 1435-1803
    Keywords: cardiac myocytes ; excitation-contraction coupling ; calcium current ; Na+−Ca2+ exchange ; Ca2+-induced Ca2+ release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Myocytes isolated from guinea pig ventricles were voltage-clamped using patch pipettes in the whole-cell configuration. For proper voltage control fast Na+ current was blocked by TTX or inactivated by an appropriate prepulse. Zero-load cell shortening was monitored by a photoelectric device. The mechanical response to a short depolarizing clamp was mainly a phasic (transient) contraction. Long-lasting depolarizations caused a tonic (sustained) shortening of a cell. Different clamp patterns were used to study the mode of activation of phasic contraction. 1) With a constant Ca2+ preload established by a train of conditioning pulses, the shortening-voltage relation measured with test pulses of varying height was a bell-shaped curve reflecting the slow inward current (ICa)-voltage relation. The test pulse had a striking influence on the first contraction of the following conditioning series, resulting in an S-shaped relation between post-test contraction and test potential. 2) With series of identical clamps of varying height, steady-state contraction was maximal around 40 mV and not in proportion to ICa. In these measurements Ca2+ preload was likely to increase with increasing potential. It is concluded that ICa initiates phasic contraction by inducing a release of Ca2+ from internal stores while replenishment of the stores is largely determined by an electrogenic transsarcolemmal Na+−Ca2+ exchange. The data suggest that Na+−Ca2+ exchange is not only involved in long-term changes of cardiac contractility but also in beat-to-beat regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01907923
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  • 7
    Electronic Resource
    Electronic Resource
    Partial and total reconstruction of the nose (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 357-361 
    Details
    ISSN: 1434-4726
    Keywords: Reconstruction ; Nose ; Forehead flap ; Temporal flap
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary For partial reconstruction of the nose we use an original forehead compound-island flap and the frontotemporal flap of Schmid-Meyer. In repairing the lower two-thirds of the nose we apply our fronto-parieto-auricular flap, which was modified by Orticochea and by Washio. For total reconstruction of the nose, we have abandoned the scalp flap of Converse and substitute in its place the fronto-parieto-occipital flap of Galvao.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00463594
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  • 8
    Electronic Resource
    Electronic Resource
    Decay of the 21/2− isomer in211Bi and structure of thevg 9 2/2 πh 9/2 levels (1989)
    Springer
    The European physical journal 332 (1989), S. 263-268 
    Details
    ISSN: 1434-601X
    Keywords: 21.60.Cs ; 23.2.0.-g ; 27.80.+w
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Gamma rays and conversion electrons have been measured in211Bi populated by the209Bi(t,p) reaction, and the near yrast levels were observed up to 21/2−. The 21/2− state is isomeric withT 1/2=70(5) ns. No alpha decaying isomer was found in211Bi. ObservedM1 transitions reveal mixing of the210Pb parent states in the levels of211Bi. The levels and transitions are well reproduced by the shell model with experimental matrix elements and pure configurations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01295455
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