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  • Articles: DFG German National Licenses  (11)
  • 1985-1989  (7)
  • 1975-1979  (4)
  • 1900-1904
  • 1987  (4)
  • 1985  (3)
  • 1979  (1)
  • 1975  (3)
Source
  • Articles: DFG German National Licenses  (11)
Material
Years
  • 1985-1989  (7)
  • 1975-1979  (4)
  • 1900-1904
Year
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 57 (1985), S. 5279-5286 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have extended the Kobayashi, Sankey, and Dow [Phys. Rev. B 25, 6367 (1982)] theory of deep levels in Hg1−xCdxTe to include (vacancy, impurity) nearest-neighbor pairs. In qualitative agreement with the results obtained by these workers for isolated point defects, we find that the composition dependences (dE/dx) of the defect energy levels associated with such complexes depend on the site occupied by the impurity atom. Furthermore, we find that the composition dependences of some of the defect levels produced by such a complex are very different than the dE/dx of levels associated with the corresponding isolated point defects. We thus suggest that this theory can often be used as an aid in the identification of the defect center producing an observed energy level. In particular, it can be used to obtain site information about an observed level and, in favorable cases, to distinguish between levels produced by isolated point defects and those produced by complexes. As an example, we compare our theoretical predictions for the dE/dx of levels associated with (vacancy, impurity) pairs to the experimental slopes of the energy levels observed in deep level transient spectroscopy by Jones, Nair, and Polla [Appl. Phys. Lett. 39, 248 (1981)] and find that the theory lends support to these workers' interpretation of their data. In addition, we present new photoluminescence data on both a previously observed and identified acceptor and on an unknown center in Hg1−xCdxTe. As a further example of the usefulness of our theory, we compare the theoretical slopes of energy levels associated with (vacancy, impurity) pairs with the composition dependences of the defect levels extracted from the photoluminescence data. The results of both of the theoretical-experimental comparisons show that the theory can be used successfully, in conjunction with experimental data, to aid in the identification of the defect center which produces an observed energy level.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 42 (1987), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Loratadine is a new non-sedating antihistamine. The present studies compared loratadine and terfenadine, another non-sedating antihistamine, for their ability to inhibit the bronchial response to histamine and other autacoids which have been implicated as contributing to the symptoms of an allergic reaction. In addition, the two antihistamines were evaluated in models of immunologically mediated allergic reactions. Loratadine is a more potent inhibitor of histamine-induced bronchospasm in guinea pigs than is terfenadine. Both antihistamines exhibit marked antiserotonin activity at doses 10 times their antihistamine ED50 values. In contrast, loratadine and terfenadine produce little or no inhibition of the bronchial responses to methacholine, leukotriene C4 or platelet-activating factor. An allergic bronchospasm in guinea pigs is inhibited by loratadine (ED50= 0.40 mg/kg, p.o.) and terfenadine (ED50= 1.7 mg/kg, p.o.). The bronchospasm associated with allergic anaphylaxis in rats is significantly inhibited by 10 mg/kg, p.o. loratadine and 30 mg/kg, p.o. terfenadine. Loratadine exhibits antiallergy activity in vitro. At micromolar concentrations, loratadine inhibits the release of histamine from Con A and A23187-stimulated rat peritoneal mast cells and the release of histamine and leukotrine C4 from a Con A-stimulated cloned murine mast cell line
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 281 (1979), S. 298-299 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] A strain of two-spotted spider mite, Tetranychus urticae Koch, resistant to an organophosphorus (OP) insecticide, was observed to be more susceptible to a synthetic pyrethroid (SP) insecticide than was a strain which had no history of exposure to insecticides. To confirm this observation ...
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The reaction64Ni(36S,34Si)66Zn atE=198 MeV has been used to measure the mass excess of34Si; a value of −19.971 −0.044 +0.037 MeV was obtained. This result which is in agreement with the previous value (−19.85±0.30 MeV) is in excellent agreement with recent shell-model mass predictions. The result is discussed within the context of the proposed region of deformation aroundZ=11,N=20.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 37 (1985), S. 306-306 
    ISSN: 1570-7458
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Solar physics 43 (1975), S. 337-350 
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The spectral composition and spatial distribution of equatorial coronal emission near 304 Å is examined. Spectral scans indicate that the predominant line is from Si xi. Comparisons of observations with calculations of intensity changes with altitude indicate that collisional excitation is important near the Sun but that photoexcitation becomes dominant beyond about 1.3 R ⊙ from the solar center. Observed and calculated intensities are in approximate agreement for abundances and electron densities that are within the range of observed values.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Solar physics 42 (1975), S. 487-496 
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The abundance of Fe relative to H is obtained by using resonantly scattered intensities of λ 284 of Fe XV that were measured with OSO-7 and resonantly scattered intensities of Lα of H I that were obtained by Gabriel (1971). Because of possible differences in electron densities along lines of sight for these non-simultaneous measurements and in relative calibrations, results are rather uncertain but still indicate that the average Fe abundance relative to H in the corona appears to be at least as large as a recent photospheric abundance. Some limitations in using this method for obtaining abundances are examined for future experiments with simultaneous measurements and well calibrated detectors.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-2048
    Keywords: Acer ; Daucus ; Cell culture ; Freeze-fracture (rapid freezing) ; Membrane recycling ; Plasma membrane ; Secretion (vesicle-mediated)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Freeze-fracture electron microscopy of propane-jet-frozen samples has been employed to investigate vesicle-mediated secretion and membrane recycling events in carrot (Daucus carota L.) and sycamore maple (Acer pseudoplatanus L.) suspension-culture cells. Stabilization of the cells by means of ultrarapid freezing has enabled us to preserve the cells in a turgid state and to visualize new intermediate membrane configurations related to these events. Indeed, many of the observed membrane configurations, such as flattened membrane vesicles with slit-shaped membrane fusion sites and horseshoe-shaped membrane infoldings, appear to result from the action of turgor forces on the plasma membrane. Individual cells exhibited great variations in numbers and types of membrane configurations postulated to be related to secretion and membrane-recycling events. In the majority of cells, the different membrane profiles displayed a patchy distribution, and within each patch the membrane configurations tended to be of the same stage. This result indicates that secretory events are triggered in domains measuring from 0.1 to about 10 μm in diameter. Based on an extensive analysis of the different membrane configurations seen in our samples, we have formulated the following model of vesicle-mediated secretion in plant cells: Fusion of a secretory vesicle with the plasma membrane leads to the formation of a single, narrow-necked pore that increases in diameter up to about 60 nm. During discharge, the vesicle is flattened, forming a disc-shaped structure perpendicular to the plane of the plasma membrane. As the vesicle is flattened, the pore is converted to a slit, the maximum length of which coincides with the diameter of the flattened vesicle. The flattened vesicle then tips over and concomitantly the plasma-membrane slit becomes curved into a horseshoe-shaped configuration as it extends along the outer margins of the tipped-over vesicle. Some coated pits are present interspersed between the above-mentioned structures, but their numbers appear insufficient to account for an exclusively endocytotic mechanism of membrane recycling. Instead, our micrographs are more consistent with a mixed mode of recycling of membrane components to the cortical endoplamic reticulum and to Golgi cisternae that involves both internalization of membrane by endocytosis and of individual lippid molecules by unknown mechanisms (lipid exchange proteins?). To this end, overall flattening out of the horseshoe-shaped membrane infoldings is accompanied by a retraction and reduction in size of their central, tongue-like structure.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1573-8868
    Keywords: data processing ; discriminant analysis ; graphics ; mapping ; sampling ; simulation ; geochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract The exploration geochemist faces a serious problem in reconciling theoretical statistics with the empirical distribution of elements in materials in the earth's crust. The results of computer-simulation experiments being conducted by the Exploration Geochemistry Group at the University of New Brunswick illustrate some of the problems of the relation between frequency distributions and spatial distributions of elements and raise some interesting questions about sampling patterns and physical size of samples. Most importantly, the simulation experiments and empirical examples support the contention that attempts to make an assumption of normality more efficient by performing log transformations on positively skewed data may defeat the purpose of statistical analysis for exploration work. New developments in computer-data presentation and interpretation, including population sorting and classification, illustrate the increasing use of the computer in exploration geochemistry.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 328 (1987), S. 379-380 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Two-dimensional γ-ray energy correlations have been measured at high spins in1800s with the TESSA2 spectrometer. The Eγ − Eγcorrelation matrix displays ridges characteristic of rotational bands with different energy separations of 96± and 72± keV for the energy regions of 660 to 840 keV and 975 to 1170 keV, respectively. The separation of these ridges remains constant in both energy regions. The dynamical moments of inertia are θ(2) =83±3 and 111±5 ħ2/MeV, respectively. The latter value suggests superdeformation in1800s with an axis ratio c/a=1.76 (β2 ≅0.64) at high spins.
    Type of Medium: Electronic Resource
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