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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 4928-4936 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A novel end-loss ion-energy spectrometer is designed for plasma-ion diagnostics in open-ended plasma-confinement devices. This analyzer significantly upgrades a previous slanted grid end-loss analyzer (SELA) to essentially eliminate secondary-electron current, and to provide a differential-spectrum mode of operation, in addition to the usual integral-spectrum operation of gridded ion-energy analyzers. The upgraded SELA does not perturb the ambient magnetic field due to its electrostatic operation. Either the differential or integral spectra are obtained by a time sweep of grid voltages, collecting the ion current on a single-channel plate. Because the angular alignment of the SELA is not critical, it can be used as a spatially scannable diagnostic of ion-energy distributions and plasma potentials. It is characterized using computer simulations of ion trajectories, monoenergetic ion beams, and end-loss plasma from the world's largest tandem mirror—GAMMA 10. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: For the purpose of plasma-ion-energy analyses in a wide-energy range from a few hundred eV to hundreds of keV, upgraded semiconductor detectors are newly fabricated and characterized using a test-ion-beam line from 0.3 to 12 keV. In particular, the detectable lowest-ion energy is drastically improved at least down to 0.3 keV; this energy is one to two orders-of-magnitude better than those for commercially available Si-surface-barrier diodes employed for previous plasma-ion diagnostics. A signal-to-noise ratio of two to three orders-of-magnitude better than that for usual metal-collector detectors is demonstrated for the compact-sized semiconductor along with the availability of the use under conditions of a good vacuum and a strong-magnetic field. Such characteristics are achieved due to the improving methods of the optimization of the thicknesses of a Si dead layer and a SiO2 layer, as well as the nitrogen-doping technique near the depletion layer along with minimizing impurity concentrations in Si. Such an upgraded capability of an extremely low-energy-ion detection with the low-noise characteristics enlarges research regimes of plasma-ion behavior using semiconductor detectors not only in the divertor regions of tokamaks but in wider spectra of open-field plasma devices including tandem mirrors. An application of the semiconductor ion detector for plasma-ion diagnostics is demonstrated in a specially designed ion-spectrometer structure. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 55 (1999), S. 719-722 
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Chester : International Union of Crystallography (IUCr)
    Journal of synchrotron radiation 6 (1999), S. 93-100 
    ISSN: 1600-5775
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Small-angle X-ray diffraction studies of the living anterior byssus retractor muscle (ABRM) of Mytilus edulis have been carried out using a long (2.2 m) point-focusing camera to investigate the overlap between the thin- and thick-filament reflections. While the reflections due to the cross-bridge lattice on the thick filaments in the resting ABRM are distant in the axial direction from the thin-filament layer lines, the paramyosin cores of the thick filaments produce reflections very close to the thin-filament reflections at axial spacings of 387, 59 and 51 Å. Using such a long camera it becomes possible to separate these reflections due to an improvement in the angular resolution and increase in the difference between the widths of the thin- and thick-filament reflections, and it is shown that the intensities of the 387 and 59 Å thin-filament layer lines gradually drop to zero close to the meridian. It becomes relatively easy to observe the thin-filament-based X-ray pattern by use of the long camera, making it possible to show a partial resemblance of the small-angle X-ray pattern from the contracting ABRM with the pattern from the rigorized ABRM.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 22 (1966), S. 591-593 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung 5-Oxykynuramin (Vorläufer von Mausamin aus Maushirn) wurde aus Urin von Huhn und Maus nach Verabreichung von Kynurenin durch Kombination der Ionen-Austausch-Chromatographie mit Papier-Chromatographie isoliert. Durch Vergleich mit dem synthetischen Präparat wurde es papierchromatographisch und durch Spaltung mittels Mäuseleberhomogenat in 4,6-Dioxychinolin und 6-Oxykynurensäure identifiziert.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1254
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 265 (1987), S. 911-915 
    ISSN: 1435-1536
    Keywords: Electrostatic interaction ; Ion-penetrablemembranes ; Ionic solubility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract An analytic, approximate expression for the electrostatic interaction between two membranes immersed in an electrolyte solution is derived on the basis of a simple membrane model. This model assumes that the membrane has a surface layer in which charged groups are uniformly distributed and that electrolyte ions can penetrate into the surface layer. The partition coefficients of cations and anions between the solution and the surface layer, which are related to their solubilities in the surface layer, may be different from unity. The electrostatic interaction depends on the ionic partition coefficients between the solution and the surface layer, and the relative permittivity of the surface layer, as well as on the membrane-fixed charges, the electrolyte concentration in the solution, and the surface layer thickness. It is shown, in particular, that even where the charge layer has no fixed charges, the electrostatic interaction force can be produced if the solubilities of cations and anions are different in the surface layer.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 243 (1986), S. 39-42 
    ISSN: 1434-4726
    Keywords: Epithelial migration ; Tympanic membrane ; External canal ; Pathology ; Cholesteatoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ink dot staining method was used to examine epithelial migration in normal ears, in pathologic tympanic membranes, and in external auditory canal cholesteatoma. The direction of the epithelial migration was found to coincide with that of the vessels in normal ears. This suggested that epithelial migration was controlled by the vessels which supply the epidermal layer of the tympanic membrane. In pathologic tympanic membranes and external auditory canal cholesteatomas, epithelial migration was disturbed to various degrees and depended on the local conditions. In these pathologic conditions, the tympanic membrane showed less vascularization. Based on our findings, we believe that a poor blood supply is the major etiologic factor for the epithelial migratory disturbances of the tympanic membrane.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 245 (1988), S. 224-229 
    ISSN: 1434-4726
    Keywords: Myringitis granulosa ; Pathogenesis ; Epithelial migration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Myringitis granulosa is not a rare pathologic condition of the tympanic membrane. However, the condition can be misdiagnosed as chronic suppurative otitis media, since intermittent purulent discharge is the commonest symptom in both disorders. Although the clinical features of myringitis granulosa have been well described by several authors, its pathogenesis is still obscure. In this study, 40 cases of myringitis granulosa were examined in detail to clarify the clinical features and the pathogenesis present. No drum perforations, no hearing impairments and normal X-ray findings indicated that myringitis granulosa had no relation to chronic suppurative otitis media. The other areas of the affected tympanic membrane, except for the site of granulation, showed such pathologic conditions as atrophy, clouding and calcifications. In these pathologic tympanic membranes, epithelial migration was disturbed to a high degree. We suggest that the granulation process on the tympanic membrane should be divided into two stages: (1) injury reaching the lamina propria of the tympanic membrane; and (2) disturbed epithelization of the tympanic membrane. The disturbance of epithelial migration of the tympanic membrane occurs with both stages.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1617-4623
    Keywords: Phosphate regulon ; RNA polymerase ; σ70 ; Region 4.2 ; PhoB
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transcription of the genes belonging to the phosphate (pho) regulon inEscherichia coli requires the specific activator protein PhoB, in addition to RNA polymerase containing the major sigma factor, σ70, which is encoded byrpoD. We previously isolated two mutant σ70s(D570G and E575K) that were specifically defective in transcribing thepho genes. The mutated sites were located near and within the first helix of the helix-turn-helix (HTH) motif of region 4.2 of σ70. To study further the role of the first helix of the HTH motif of σ70 in transcriptional activation by PhoB, we made a series ofrpoD mutations that alter the motif and purified the mutant σ70 proteins. RNA polymerases containing the mutant σ70s Y571A, T572L, V576T, K578E and F580V showed reduced in vitro transcription from thepstS promoter, a representativepho promoter, in the presence of PhoB, whereas RNA polymerase containing another mutant σ70 (E574 K) showed enhanced transcription from the promoter. Transcription from the activator-independenttac promoter and thepBR-P4 promoter, which is independent of PhoB and requires cAMP-CRP (cAMP receptor protein) for transcription, was affected at most only marginally by these σ70 mutations. These results provide further evidence that the first helix plays an important role in the specific interaction between RNA polymerase and PhoB protein bound to thepho promoters in transcriptional activation.
    Type of Medium: Electronic Resource
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