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  • 1
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 109-111 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Subpicosecond wavelength-degenerate differential transmission optical spectroscopy was used to characterize the electron capture time in a 10-period InxGa1−xN multiple-quantum-well (MQW) structure. Photoluminescence and photoluminescence excitation spectroscopies demonstrated enhanced MQW emission for injection within ±50 meV of the barrier energy. Time-resolved differential transmission measurements for excitation in this region reveal efficient electron capture in the quantum wells with a time constant between 310 and 540 fs. A slower exponential relaxation, with strongly wavelength-dependent subnanosecond decay constants, is also observed. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Journal of fish biology 63 (2003), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The concept of habitat selection based on ‘Ideal Free Distribution’ theory suggests that areas of high suitability may attract larger quantities of fishes than less suitable or unsuitable areas. Catch data were used from groundfish surveys to identify areas of consistently high densities of whiting Merlangius merlangus, cod Gadus morhua and haddock Melanogrammus aeglefinus in the Irish Sea and plaice Pleuronectes platessa, sole Solea solea, lemon sole Microstomus kitt in the English Channel over a period of 10 and 9 years respectively. A method was introduced to delineate areas of the seabed that held consistently high numbers of fishes objectively from large datasets. These areas may constitute important habitat characteristics which may merit further scientific investigations in respect to ‘Essential Fish Habitats’(EFH). In addition, the number of stations with consistently high abundances of fishes and the number of stations where no fishes were caught gave an indication of the site specificity of the fish species analysed. For the gadoids, whiting was found to be less site specific than cod and haddock, while for the flatfishes, plaice and sole were less site specific than lemon sole. The findings are discussed in the context of previously published studies on dietary specializm. The site specificity of demersal fishes has implications for the siting process for marine protected areas as fish species with a strong habitat affinity can be expected to benefit more from such management schemes.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Science Ltd/Inc.
    Journal of fish biology 64 (2004), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Given a choice of habitats in a laboratory experiment, whiting Merlangius merlangus preferentially spent most time over sand, then gravel and least time over a habitat with emergent structures. The introduction of a predator stimulus increased the preference for the sand habitat for large whiting, whereas small whiting had an increased preference for the habitat with emergent structures.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 513 (1987), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    International orthopaedics 13 (1989), S. 13-16 
    ISSN: 1432-5195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les ligaments croisés du genou ont été réséqués avec leurs insertions osseuses au cours d'arthroplasties totales du genou réalisées sur douze sujets atteints de graves lésions d'arthrose ou de polyarthrite rhumatoïde. Les ligaments ont été étudiés sur le plan histologique et biomécanique, et dix spécimens provenant d'adultes sains ont été utilisés comme contrôle. On a mis en évidence des différences significatives de la résistance et des propriétés visco-élastiques des ligaments entre ceux des patients arthrosiques et les autres. Les ligaments des genoux rhumatoïdes présentaient une résistance nettement plus faible comparativement à ceux des genoux arthrosiques. L'arthroplastie totale du genou qui remplace également la fonction ligamentaire, peut donc être efficace dans les genoux rhumatoïdes, grandement endommagés.
    Notes: Summary The cruciate ligaments were resected with their bony insertions during total knee arthroplasty carried out in 12 patients with severe rheumatoid or osteoarthritis. The ligaments were examined histologically and biomechanically, using ten specimens from healthy adults as a control. A significant difference was found in the tensile stiffness and viscoelastic properties of the ligaments between the arthritic and the control group. The ligaments in the rheumatoid knees had a distinctly inferior tensile strength compared with the osteoarthritic knees. Total knee replacement, which also replaces ligament function, should therefore be considered in severely damaged rheumatoid knees.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-0827
    Keywords: Key words: Ultrasound densitometry — Body composition — Fat mass — Lean body mass — Epidemiology.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. Body mass is known to be related to measures of bone mineral density (BMD) as well as to parameters of quantitative ultrasound (US). To examine the effect of the body compartment's fat mass and lean body mass on quantitative ultrasonic bone parameters, data from a sample of 3241 German women were analyzed. Anthropometric measures, including skinfold thickness, were obtained from standardized measurements, and fat and lean body mass were derived from classical regression formulas based on skinfold measurements. Ultrasonic bone measurements were performed on the right os calcis, and speed of sound (SOS) and broadband ultrasound attenuation (BUA) were determined. Women were grouped into pre- and postmenopausal status; postmenopausal women were further stratified into ever and never hormone-replacement user. Correlation analysis indicated lean body mass to be stronger correlated with BUA than fat mass in both pre- (r = 0.23; P= 0.0001) and postmenopausal women with (r = 0.19; P= 0.0001) and without hormone replacement therapy (HRT) (r = 0.26; p = 0.0001). SOS demonstrated very small or no associations with body mass or its components. Multiple linear regression models were used to describe the relationship among body weight, fat mass, and lean body mass on BUA after adjustment for confounding variables. Both in pre- and postmenopausal women lean body mass was more strongly related to BUA than fat mass. However, body mass measures explained only small amounts of the overall variance in BUA (R2= 1–3% in premenopausal women; R2= 1% postmenopausal with HRT; R2= 4–5% in postmenopausal women without HRT). In conclusion, the strong influence of body mass and its components previously reported for BMD was not observed for quantitative ultrasonic bone parameters.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 73 (1987), S. 349-356 
    ISSN: 1432-0533
    Keywords: Blood-brain barrier ; Cortex ; Lanthanum tracer ; Potassium ; Ion-selective micro-electrode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using lanthanum nitrate as a tracer, the permeability of rat cortical blood vessels was investigated during regional hypothermia of the cerebral cortex by electron microscopy. The concentration of K+ ions in the extracellular space of the cortex was determined using an ion-selective micro-electrode. Only at temperatures below about 7°C was an extravasation of tracer observed in a number of cortical capillaries and arterioles, where some of the tight junctions became widened and permeable. In a few cases penetration of the tracer into vacuoles of phagocytosing pericytes or macrophages was found. The extravasation of the tracer could mainly be observed in vessels on and below the cortical surface, less often in deeper cortical parts. At the same degree of hypothermia, the K+ concentration in the extracellular space increased, reaching a maximal value of ca. 6 mmol/l at a depth of about 200 μm. As could be shown in one previous experiment, the K+ concentration reached normal values again after rewarming to 37°C for 15 min, but an extravasation of the tracer was still observed. The role of the endothelial tight junctions and of the astrocytes together with the pericytes (or macrophages) is discussed regarding their importance for the effectiveness of the blood-brain barrier system.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1435-1536
    Keywords: Polymer adsorption ; IR spectrometry ; fraction of adhered segments ; silica
    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 The adsorption of N-ethylpyrrolidone (NEP), oligomeric and polymeric vinylpyrrolidone (OVP, PVP) on silica (Aerosil 200) from CHCl3 solution is investigated by IR spectrometry. The influence of the annealing temperature of the silica on the adsorbed amount and on the fraction of adhered segments was studied. The dependences of the amount adsorbed on solution concentration result for NEP in a Langmuir isotherm for OVP and PVP in high affinity isotherms. The fraction of adhered H-bridged carbonyl groups determined by compensation procedures, the fraction of surface SiOH groups occupied and the multiple interaction quotientQ show different dependences on the amount adsorbed for the measured adsorptives, indicating different interactions of the monomeric segments with the surface groups. This behaviour is explained by comparing the amount adsorbed in saturation with monolayer capacities, surface concentration of SiOH groups and frequency shifts. A splitting of the band of the bound carbonyl groups in a double peak was observed with OVP and PVP, referring to an additional interaction of polymer segments neighboured to specifically bound segments.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 263 (1985), S. 381-387 
    ISSN: 1435-1536
    Keywords: polymer adsorption ; microcalorimetry ; enthalpy of adsorption ; fraction of adhered segments ; silica
    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 Adsorption enthalpies of N-ethylpyrrolidone, oligomeric and polymeric vinylpyrrolidone from CHCl3 solution on silica interfaces (Aerosil 200) have been measured at 25 °C by microcalorimetry. The dependence on surface coverage has been examined using measured adsorption isotherms. Binding enthalpies are calculated with fractions of adhered segments obtained by IR spectrometry and wetting enthalpies received from calorimetry. Fractions of adhered segments are derived from the adsorption enthalpies assuming equal binding enthalpies of monomers and polymer segments and considering desorption enthalpies of the solvent depending on the surface area of the polymer segments. The resulting enthalpies are compared with literature values from other solvents and the incongruity of the fraction of adhered segments obtained by IR, ESR, NMR and microcalorimetry is explained.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical microbiology & infectious diseases 7 (1988), S. 190-193 
    ISSN: 1435-4373
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A fosfomycin disk (200 µg) placed on blood agar was used to select diphtheroids from clinical specimens. AllCorynebacterium type strains tested, representing ten different groups of diphtheroids, and 150 toxigenic strains ofCorynebacterium diphtheriae from different outbreaks, overgrew the fosfomycin disk, while other aerobic gram-positive rods had a large inhibition zone. The method increased the rate of isolation of diphtheroids in 1267 clinical specimens fivefold, from 1.4 % to 7.6 %, especially when the diphtheroids were found concomitantly with other bacteria. Overgrowth of the disk by other microorganisms occurred in 11 % of the samples tested, but such microorganisms could easily be distinguished by culture morphology or Gram stain. Fosfomycin disks provide a simple, highly sensitive but not very specific aid for isolation ofCorynebacterium diphtheriae and diphtheroids from clinical specimens.
    Type of Medium: Electronic Resource
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