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  • 1
    Electronic Resource
    Electronic Resource
    Possibility of multiple tunnelling current peaks in a coupled quantum well system (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 943-947 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this work, we have numerically integrated in space and time the effective-mass nonlinear Schrödinger equation for an electron wave packet in a bilayer electron system. Considering both Hartree and exchange-correlation potentials, we have calculated the tunnelling rates between the two quantum wells when an external bias is applied in the double quantum well system. Due to the nonlinear effective-mass equation, it is found that the charge dynamically trapped in both wells produces a reaction field which modifies the system resonant condition. At different electronic sheet densities, we have shown the possibility of having multiple resonant tunnelling peaks in a bilayer electron system. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.373760
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  • 2
    Electronic Resource
    Electronic Resource
    High-performance quantum cascade lasers (λ∼11 μm) operating at high temperature (T ≥425 K) (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 416-418 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report record-low threshold current density and high output power for λ∼11 μm Al0.48In0.52As/Ga0.47In0.53As quantum cascade lasers operating up to 425 K. The threshold current density is 1.1, 3.83, and 7.08 kA/cm2 at 80, 300, and 425 K, respectively, for 5 μs pulses at a 200 Hz repetition rate. The cavity length is 3 mm with a stripe width of 20 μm. The maximum peak output power per facet is 1 W at 80 K, 0.5 W at 300 K, and more than 75 mW at 425 K. The characteristic temperature of these lasers is 174 K between 80 and 300 K and 218 K in the range of 300–425 K. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1343848
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  • 3
    Electronic Resource
    Electronic Resource
    Low-threshold and high power λ∼9.0 μm quantum cascade lasers operating at room temperature (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 1741-1743 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report a low threshold current density and high power for λ∼9 μmAlInAs/GaInAs quantum cascade lasers operating at room temperature. The threshold current density is 1.95 kA/cm2 at 300 K and 0.61 kA/cm2 at 80 K for 5 μs pulses at 200 Hz repetition rate. The peak output power is 700 mW at room temperature and 1.3 W at 80 K per two facets for cavity length is 3 mm with a stripe width of 20 μm. The characteristic temperature T0 is 185 °C. The slope efficiency is 450 and 800 mW/A at 300 and 80 K, respectively. In continuous wave operation, the output power is more than 150 mW at 80 K and 25 mW at 140 K. This high performance was achieved by improving the material growth and processing technology. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1310632
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of Soy Glycinin Addition on the Conformation and Gel Strength of Two Pork Myosin Types (2003)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 68 (2003), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The pale, soft, and exudative (PSE) condition in pork meat has been associated with protein dena-turation that leads to loss of functional properties. The effect of soy glycinin addition to model systems of actomyosin from PSE or normal meat on biophysical properties was evaluated. Although the functional properties depended on actomyosin concentration, a 75% actomyosin/25% glycinin mixture presented acceptable properties with both types of actomyosin. This combination was used to investigate protein-protein interactions. Gel strength correlated with intermediate a-helical content and protein aggregation. Changes in protein secondary structure probably added to protein denaturation appear to be necessary to improve gelation and water retention in PSE actomyosin-glycinin combinations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.2003.tb05795.x
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  • 5
    Electronic Resource
    Electronic Resource
    Development of a new disease-specific quality-of-life questionnaire to adults living with haemophilia (2004)
    Oxford, UK : Blackwell Science Ltd
    Haemophilia 10 (2004), S. 0 
    Details
    ISSN: 1365-2516
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary.  A haemophilia-specific health-related quality-of-life questionnaire (named ‘Hemofilia-QoL’) was developed to assess quality-of-life in adults with haemophilia, and was psychometrically tested. Seventy-three interviews with haemophilia patients and health care professionals were used to generate the items included in the questionnaire, and expert ratings on the items formulated were used to screen them for potential omission. This was followed by psychometric testing in a sample of 35 patients. Preliminary psychometric testing of the revised questionnaire version, which contains 10 domains (physical health, physical role, joint damage, pain, treatment satisfaction, emotional role, mental health, social support), showed acceptable reliability (α = 0.94 for the Hemofilia-QoL total score) and validity, and this will be examined in a subsequent study with a larger patient sample.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2516.2004.00918.x
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  • 6
    Electronic Resource
    Electronic Resource
    Towards a ‘Human-like’ Model of Tuberculosis: Intranasal Inoculation of LPS Induces Intragranulomatous Lung Necrosis in Mice Infected Aerogenically with Mycobacterium tuberculosis (2001)
    Oxford, UK : Blackwell Science Ltd
    Scandinavian journal of immunology 53 (2001), S. 0 
    Details
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: It is well known that one of the differences between murine and human tuberculosis is the lack of intragranulomatous necrosis in the former. The aim of this study was to create a feasible and reproducible model of an experimental model of murine tuberculosis in which this necrosis should be present. Considering the Shwartzman reaction as a possible explanation for intragranulomatous necrosis in human tuberculosis, C57Bl/6 mice, infected aerogenically with a virulent strain of Mycobacterium tuberculosis, were intranasally inoculated with lipopolysaccharide (LPS) on day 19 postinfection (p.i.). Twenty-four hours later, neutrophils infiltrated the lung parenchyma in a significant level, and 10 days after necrosis could be detected in the centres of primary granulomas, that showed scanty macrophages and large amounts of collagen on an eosinophilic background. On the other hand, a significant decrease in the concentration of colony forming units (CFU) could be appreciated 24 h after the LPS inoculation. Afterwards, nonbronchogenic spreading of granulomas increased and higher levels of interferon (IFN)-γ mRNA were detected. These results lend support to the Shwartzman reaction as the origin of the intragranulomatous necrosis in the M. tuberculosis infection, and provides a useful tool to improve experimental murine models in tuberculosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3083.2001.00842.x
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  • 7
    Electronic Resource
    Electronic Resource
    Development of the lateral line system in the sea bass (2003)
    Oxford, UK : Blackwell Science Ltd
    Journal of fish biology 62 (2003), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Using light and electron microscopy, a study of the development of the lateral line system of the sea bass Dicentrarchus labrax, from embryo to adult, revealed that the first free neuromasts appeared on the head shortly before hatching and multiplied during the larval stage. They were aligned on the head and trunk in a pattern which corresponded to the location of future canals. The transition to the juvenile stage marked the start of important anatomical changes during which head and trunk canals were formed successively. Neuromasts, with a cupula and consisting of standard sensory cells and supporting cells, were characterized by bidirectional polarity. The exact location of the first neuromast formed in the embryo was identified and its differentiation monitored from primordium to eruption. This neuromast was distinguishable from the others by its radial polarity. Correlations were made between the development of the lateral line system and the behaviour of the sea bass.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1095-8649.2003.00004.x
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  • 8
    Electronic Resource
    Electronic Resource
    Structural and antigenic differences between two types of meningococcal pili (1984)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 21 (1984), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Strains of meningococci, which were shown to be pilated by electron microscopy, could be divided into two groups on the basis of antigenicity and subunit Mr. Strains from group 1 which reacted with monoclonal antibodies directed against gonococcal pili, had pili with subunit Mr similar to that of gonococci which could be detected by radioimmune precipitation or electroblotting. Strains from group 2 failed to react with the monoclonal antibodies and had pili with lower subunit Mr which could only be detected by radioimmune precipitation using polyclonal antipilus antiserum and not by electroblotting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1984.tb00207.x
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  • 9
    Electronic Resource
    Electronic Resource
    The steady-state relationship between sodium and chloride transmembrane electrochemical potential differences inNecturus gallbladder (1980)
    Springer
    The journal of membrane biology 55 (1980), S. 213-222 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Intracellular C1, K and Na activities (a Cl i ,a k i anda Na i ) and transmucosal membrane potential (E m) in epithelial cells ofNecturus gallbladder were measured at different external Na concentrations ([Na]o), with liquid ion-exchanger and conventional microelectrodes. Bladders were mounted in a divided chamber at 23°C between identical HCO3-free Ringer solutions containing 5mm K. The pH was 7.2. Tris was substituted for Na. Measurements were made under steady-state conditions as determined by the constancy of the transepithelial potential difference. Both,a Cl i anda Na i increased in a saturable fashion with [Na]o.E m did not change significantly. Average values (±sem) under normal conditions ([Na]o=100mm) fora Cl i ,a Na i andE m were 16.8±0.8mm (n=9), 9.7±0.6mm (n=10) and −52.6±0.6 mV (n=26), respectively. In Na-free mediaa Cl i declined to its equilibrium value.a K i (96±2mm;n=7) did not change when [Na]o was varied between 100 and 10mm but decreased to 80±3mm (n=4) in Na-free media. Transmembrane electrochemical potential differences, $$\Delta \bar \mu _j $$ , for Cl and Na were calculated at four different [Na]o levels. A highly significant linear relation between $$\Delta \bar \mu _{Cl} $$ and $$\Delta \bar \mu _{Na} $$ was found, indicating that Cl and Na transport are energetically linked. The results support the view that the energy necessary for intracellular Cl accumulation is derived from the simultaneous dissipation of the chemical potential gradient of Na across the apical membrane and that the coupled entry mechanism is electroneutral.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869462
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  • 10
    Electronic Resource
    Electronic Resource
    Intracellular ionic activities in frog skin (1981)
    Springer
    The journal of membrane biology 61 (1981), S. 127-134 
    Details
    ISSN: 1432-1424
    Keywords: Frog skin ; microelectrodes ; membrane potentials ; intracellular activities ; amiloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Intracellular Na+, K+, and Cl− activities (a Na i ,a K i ,a Cl i ) and transapical membrane potentials (V o) were measured with liquid ion-exchanger and open-tip microelectrodes in isolated short-circuited frog skins (R. pipiens) incubated at 23°C in normal amphibian Ringer's solution. Under control conditionsa Na i =14±3mm,a K i =132±10mm anda Cl i =18±3mm (sd). The value ofa Cl i is 4.4 times the value corresponding to electrochemical equilibrium for this ion. Thus, Cl− is actively accumulated by epithelial cells of the frog skin. Shortly after addition of amiloride (2–5 μm) to the apical bathing medium,a K i ,a Na i , anda Cl i were essentially unchanged althoughV o had hyperpolarized by about 30–40 mV. During long-term exposure to amiloridea K i anda Cl i did not change significantly,V o depolarized by about 16 mV from the maximal value anda Na i decreased to 8±3mm. Immediately after exposure to amiloride the transmembrane driving force for Na+ increased from 124 to 154 mV. During further exposure to amiloride, despite changes in bothV o anda Na i , this driving force remained virtually constant. SinceI sc during this period was close to zero, it is suggested that the observed driving force for Na+ under these conditions approximates the maximal driving force generated by the Na+−K+ ATP-ase pump in the basolateral cell membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02007639
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