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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 7263-7266 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Grain boundaries in doped lanthanum manganites have been shown to have a large low-field magnetoresistance. However, the mechanism of electrical transport across grain boundaries, and the origin of the low-field magnetoresistance, are not well understood. Models based on scattering at domain walls, spin-polarized tunneling and depression of the Curie temperature due to strain near the grain boundary have all been proposed. This article reports detailed studies of the transport properties of artificial grain boundaries formed in a variety of thin films grown on bicrystal substrates. Resistance versus field sweeps on all grain boundary devices showed strong low-field magnetoresistance and the effect of individual domain motion at the grain boundary has been observed in single grain boundaries. In all cases, current versus voltage characteristics were highly non-ohmic, and reminiscent of an electron tunneling process. However, the magnetic dependence of the current–voltage characteristics implies that the magnetoresistance may be unrelated to tunneling. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 7157-7159 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We have observed a strong correlation between the degree of epitaxy and the low field resistance versus field R(H) behavior in highly textured La0.7Sr0.3MnO3 films grown by pulsed laser deposition on SrTiO3 substrates. Highly epitaxial films show a small temperature dependent low field hysteretic R(H) peak near the magnetic ordering temperature (Tc), when the applied field is parallel to the transport current (J(parallel)H). In contrast, films with reduced epitaxy show a much larger low field hysteretic R(H) behavior with a pronounced in-plane angular dependence. The magnitude of this response grows with decreasing temperature below Tc. Our data and analysis suggest that even low angle grain boundaries play a fundamental role in transport properties in colossal magnetoresistive materials. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 2038-2040 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The resistance of polycrystalline doped LaMnO3 materials has been shown to be highly sensitive to low magnetic fields. To enable direct study of the properties of isolated grain boundaries we have grown epitaxial La0.7Sr0.3MnO3 films on a series of bicrystal substrates with different misorientation angles and patterned the films into a Wheatstone bridge geometry. We show that the grain boundary resistance and its magnetic field dependence vary strongly with the misorientation angle. The temperature dependence of the grain boundary resistance is also presented. We have obtained resistance changes of over 3% in fields of 2 mT at 300 K. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    International journal of dermatology 24 (1985), S. 0 
    ISSN: 1365-4632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: Biopsy specimens from 17 Zairians with chromomycosis are described. Patients ranged in age from 20 to 50 years, with a mean of 37.2 (10.2). Chromomycosis was suspected clinically in only 3 of the 17 patients. In 14 patients the lesions were on the lower limbs and in 3 on the arms. The lesions were chronic, in one patient persisting (or 9 years. The diagnosis was established in each patient by finding typical thick-walled brown fungi within the lesions. Some fungi were in abscesses, others were in histiocytes or giant cells. The fungi and the inflammatory reaction were concentrated in the upper dermis. Acanthosis, hyperkeratosis, and parakeratosis were constant features and pseudoepithe- liomatous hyperplasia (PEH) was a feature in 10 patients. Transepithelial elimination (TEE) of fungi was a conspicuous feature in eight specimens. Microscopic features suggested TEE in an additional three. PEH and TEE were associated in all specimens. In patients with TEE, the diagnosis may he confirmed quickly by smearing surface scrapings and finding the characteristic brown fungi.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    International journal of dermatology 25 (1986), S. 0 
    ISSN: 1365-4632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: : The effects of treatment and depths of penetration of a 5–fluorouracil and salicylic acid preparation (Solcoderm) were studied in 24 patients treated for basal cell carcinoma with this compound. Two thirds of the patients in our study showed islands of residual tumor in the dermis following treatment, whereas total disappearance of the tumor was observed in one third. The depth of the fibrotic changes induced by the drug varied from 0.34 to 0.40 cm for the morphea type of basal cell carcinoma and from 0.52 to 0.88 cm for the conventional types. It is recommended that treatment with this compound be reserved only for superficial basal cell carcinomas and that it be avoided altogether in basal cell carcinoma of the morphea type.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    International journal of dermatology 25 (1986), S. 0 
    ISSN: 1365-4632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    International journal of dermatology 24 (1985), S. 0 
    ISSN: 1365-4632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: : Biopsy specimens from 17 Zairians with chromomycosis are described. Patients ranged in age from 20 to 50 years, with a mean of 37.2 (±10.2). Chromomycosis was suspected clinically in only 3 of the 17 patients. In 14 patients the lesions were on the lower limbs and in 3 on the arms. The lesions were chronic, in one patient persisting for 9 years. The diagnosis was established in each patient by finding typical thick-walled brown fungi within the lesions. Some fungi were in abscesses, others were in histiocytes or giant cells. The fungi and the inflammatory reaction were concentrated in the upper dermis. Acanthosis, hyperkeratosis, and parakeratosis were constant features and pseudoepitheliomatous hyperplasia (PEH) was a feature in 10 patients. Transepithelial elimination (TEE) of fungi was a conspicuous feature in eight specimens. Microscopic features suggested TEE in an additional three. PEH and TEE were associated in all specimens. In patients with TEE, the diagnosis may be confirmed quickly by smearing surface scrapings and finding the characteristic brown fungi.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    ISSN: 1365-3059
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Leaf spot disease of celery (Apium graveolens), caused by the fungus Septoria apiicola, is a major disease for which there is only limited host resistance. Some factors affecting the response of the fungus to essential oil components of host tissue were investigated using a susceptible blanching celery (var. Celebrity) and a more resistant green celery (var. Cutting) as hosts. After infection the time taken for pycnidia to appear on the surface was 16 days in Cutting and 13 days in Celebrity, but only limited leaf necrosis occurred in Cutting whereas the whole leaf rapidly became necrotic in Celebrity. Although the composition of the essential oil (limonene, β-pinene, terpinene, caryophyllene, sesquiterpenes and phthallides) was comparable in both varieties, Cutting contained over four times the total concentration of oil found in Celebrity. Extracts of the essential oil from Cutting were found to be more inhibitory to the growth of Septoria in culture. Of the terpenes tested (limonene, β-pinene, and caryophyllene), β-pinene was most inhibitory to the growth of hyphae on solid and liquid media. The role of the essential oil as part of a constitutive defense mechanism in host resistance to Septoria is discussed.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1520-6904
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of organic chemistry 41 (1976), S. 1146-1152 
    ISSN: 1520-6904
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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