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  • 1
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 539-543 (Mar. 2007), p. 1309-1314 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The SOFC technology under development at Risø National Laboratory (RISØ) andTopsoe Fuel Cell A/S (TOFC) is based on an integrated approach ranging from basic materialsresearch on single component level over development of cell and stack manufacturing technology tosystem studies and modelling. The effort also comprises an extensive cell and stack testingprogram. Systems design, development and test is pursued by TOFC in collaboration with variouspartners. The standard cells are thin and robust with dimensions of 12 x 12 cm2 and cell stacks arebased on internal manifolding. Production of cells is being up-scaled continuously. The durabilityof the standard stack design with standard cells has been tested for more than 13000 hours includingnine full thermal cycles with an overall voltage degradation rate of about 1% per 1000 hours.Recently, the degradation rate has been significantly reduced by introduction of improved stackcomponent materials. 75-cell stacks in the 1+ kW power range have been tested successfully. Stackshave been delivered in a pre-reduced state to partners and tested successfully in test systems withnatural gas as fuel. The consortium of TOFC and RISØ has an extended program to develop theSOFC technology all the way to a marketable product. Stack and system modelling including costoptimisation analysis is used to develop multi kW stack modules for operation in the temperaturerange 700-850oC. To ensure the emergence of cost-competitive solutions, a special effort is focusedon larger anode-supported cells as well as a new generation of SOFCs based on porous metalsupports and new electrode and electrolyte materials. The SOFC program comprises developmentof next generation of cells and multi stack modules for operation at lower temperature withincreased durability and mechanical robustness in order to ensure long-term competitiveness
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 30 (1989), S. 0 
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The relationship between free cytoplasmic calcium, activation of protein kinase C (PKC) and expression of high-affinity interleukin 2 receptors (HA-IL-2R) on human T lymphocytes was studied. Induction of HA-IL-2R by phytohaemagglutinin (PHA) was associated with an increase in free cytoplasmic calcium and a transient increase in membrane-associated PKC. However, whereas addition of EGTA inhibited induction of receptors by PHA, addition of the PKC-inhibitor H7 did not. 12-o-tetradecanoyl-phorbol-13-acetate (PMA) and 1-oleoyl-2-acetyl-racglycerol (OAG) were both found to activate and translocate PKC. However, only PMA induced expression of HA-IL-2R. Not surprisingly, the effect of PMA was independent of extracellular calcium, but was inhibited by H7. Furthermore, a correlation between the number of HA-IL-2R and free cytoplasmic calcium upon stimulation with ionomycin was observed. Associated with the rise in intracellular calcium, the ionophore caused a slight increase in membrane-associat4ed PKC. Also, addition of 117 inhibited expression of HA-IL-2R. Finally, OAG and ionomycin acted synergistically on expression of HA-IL-2R. In conclusion, induction of HA-IL-2R requires at least two different signals and neither activation of PKC nor an increase in free cytoplasmic calcium is sufficient. However, these two signals may act synergistically. There is evidence for both a PKC- and calcium-independent pathway.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 29 (1989), S. 0 
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The subcellular localization of protein kinase C in unstimulated human neutrophils and neutrophils stimulated by phorbol-myristate-acetate (PMA), 1-oleoyl-2-acetyl-rac-glycerol (OAG), and ionomycin was investigated in subcellular tractions obtained by nitrogen cavitation and Percoll density gradient centrifugation. Protein kinase C was found to he localized mainly in the cytosol in unstimulated cells, whereas significant translocation to fractions containing the plasma membrane was observed after stimulation by PMA, OAG, and ionomycin. At the same time, phospholipid-insensitive protein kinase activity appeared in the cytosol and the plasma membrane fractions. To determine whether binding of protein kinase C occurred to the plasma membrane or to intracellular membranes that had translocated to the plasma membrane, we investigated the ability of isolated azurophil, specific and secretory granules, and plasma membrane vesicles to bind protein kinase C in response to addition of PMA and OAG. Only fractions containing plasma membranes and secretory granules were able to bind protein kinase C. The observation explains the selective activation of plasma membrane structures by protein kinase C.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/General Subjects 884 (1986), S. 54-59 
    ISSN: 0304-4165
    Keywords: (Leukocyte membrane) ; Phorbol ester ; Phospholipid ; Protein kinase C
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 28 (1988), S. 0 
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Phorbol myristate acetate (PMA) and 1-oleoyl-2-acetyl-rac-glycerol (OAG) are shown to induce a rapid (within 30 min) down-regulation of the capacity of activated human T lymphocytes to bind interleukin 2. This was associated with a manifold increase in membrane-associated protein kinase C, whereas no change in free cytoplasmic calcium was observed. In contrast, a 10-fold increase in free cytoplasmic calcium by ionomycin had no effect on interleukin 2 binding or sub-cellular distribution of protein kinase C. The reduction of interleukin 2 binding was caused by a decreased number of high-affinity interleukin 2 receptors, whereas the affinity of the remaining receptors was unchanged. However, PMA and OAG had no effect on the rate of initialization of the interleukin receptor. These data suggest that activation of protein kinase C. but not an increase in free cytoplasmic calcium, leads to a rapid decrease in the number of high-affinity interleukin 2 receptors on activated human T lymphocytes. However, the mechanism and biological importance of this phenomenon have to be further elucidated.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Experiments in fluids 15 (1993), S. 380-384 
    ISSN: 1432-1114
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A two-component, hot-film probe has been developed, to measure the wall shear stress as a vector quantity in time-dependent flows. The probe has been applied for the measurements of the bottom shear stress in a flow generated by combined waves and current in a water basin where the magnitude and the direction of the bottom shear stress varied periodically with respect to time. The probe has also been used to measure the bottom shear stress around a vertical cylinder exposed to water waves generated in a wave flume.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1433-0423
    Keywords: Schlüsselwörter: Applanationstonometrie ; Mackay- Marg-Prinzip ; Manometrie ; Key words: Applanation tonometry ; Mackay-Marg principle ; Manometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: In a randomised clinical study two new microprocessor-controlled tonometers working according to the Mackay-Marg principle (Tono-Pen and ProTon, two samples of each) and two established applanation tonometers [hand-held applanation tonometer, Draeger (HAT) and Goldmann tonometer] were compared with respect to accuracy, precision, examiner dependence and internal measurement differences (Tono-Pen I vs II, ProTon I vs II). The four tonometers were used by two examiners six times on each of 193 eyes of 100 patients of the university eye department. The same measuring procedure was performed on four cadaver eyes in situ, using a manometer system. The correlation coefficient between Tono-Pen and HAT and between ProTon and HAT was 0.9, with a high standard deviation, about ±3.1 mmHg. HAT gave the best results in repetitive measurements in the same eye (precision: r = 0.92, SD = ±1.41 mmHg). In applanation tonometers but not in Mackay-Marg tonometers measurement values depended significantly on the physician. There was a significantly higher standard deviation between Tono-Pen I and II than between ProTon I and II. Concerning in vitro calibration series on human bulbs (manometry), accuracy was high with each tonometer. The regression line of HAT is similar to that of ProTon. Tono-Pen overestimates the manometrically determined intraocular pressure. Because of their lack of precision the two new tonometers are not suitable for clinical use.
    Notes: In einer randomisierten klinischen Kalibrationsstudie wurden 2 neu-artige mikroprozessorgesteuerte Tonometer vom Mackay-Marg-Prinzip (Tono-Pen, ProTon; pro Tonometer je 2 Exemplare) und 2 herkömmliche Applanationstonometer (Handapplanationstonometer nach Draeger-, HAT-, Goldmann-Tonometer) von 2 Untersuchern an 193 Augen von 100 Patienten der Universitäts-Augenklinik sowie in vitro (Manometrie am Humanbulbus) angewandt. Die Meßergebnisse wurden hinsichtlich ihrer Reproduzierbarkeit, Genauigkeit, Untersucherabhängigkeit und geräteinterner meßtechnischer Differenzen statistisch ausgewertet. Die Korrelation der Tono-Pen- und ProTon-Meßwerte mit denen des HAT (Meßgenauigkeit) zeigt hohe Standardabweichungen (SD um ±3,1 mmHg) bei einem Korrelationskoeffizienten r um 0,9. Die Reproduzierbarkeit von Wiederholungsmessungen eines Tonometers an einem Auge ergibt beim HAT mit r = 0,92 und SD ± 1,41 mmHg das beste Resultat. Die Applanationstonometermeßwerte zeigen gegenüber denjenigen der Mackay-Marg-Tonometer eine statistisch signifikante Untersucherabhängigkeit. Beim internen Tonometervergleich liegt die Streuung zwischen den Tono-Pen-Geräten signifikant über derjenigen der ProTon-Tonometer. Die Reproduzierbarkeit von Einzelmessungen ist in vitro bei allen 4 Instrumenten hoch. Die Regressionsgeraden von HAT und ProTon sind ähnlich konfiguriert. Das Tono-Pen überschätzt den vorgegebenen Manometerdruck. Bei mangelnder Präzision sind die beiden neuartigen Tonometer Tono-Pen und ProTon in der vorliegenden Ausführung für den klinischen Gebrauch ungeeignet.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Inflammation research 28 (1989), S. 121-129 
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Auranofin (AF), a lipophilic chrysotherapeutic agent, was investigated for its effect on the formation of lipoxygenase products and the activity of protein kinase C in human neutrophils. We have previously shown that inhibition of LTB4 formation by 5-lipoxygenase (5-LO) inhibitors is intimately associated with a marked increased in 15-HETE in excess of arachidonic acid. The calcium- and phospholipiddependent protein kinase, protein kinase C, is activated in FMLP- and A23187-stimulated neutrophils, is hypothesized to stimulate superoxide generation, and plays an essential role in eicosanoid production. AF dose-dependently inhibited the generation of leukotriene B4 (LTB4) in FMLP-stimulated neutrophils, the ID50 was approximately 4.5 μg/ml. Unlike known 5-LO inhibitors, AF did not enhance the production of 15-HETE. In neutrophils stimulated with the calcium ionophore, A23187, AF did not inhibit the generation of LTB4 nor did AF change the 15-HETE levels. AF inhibited superoxide generation in FMLP-stimulated neutrophils dose-dependently, but did not change the activation of protein kinase C in the cells. We therefore conclude, that AF inhibition of LTB4 production in neutrophils is different from 5-lipoxygenase inhibitors and is elicited at a step distal to protein kinase C activation.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Applied microbiology and biotechnology 47 (1997), S. 91-94 
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract   Reductive dechlorination of tetrachloroethene was studied in a mesophilic upflow anaerobic sludge blanket reactor. Operating the reactor in batch mode the dynamic transformation of tetrachloroethene, trichloroethene and dichloroethene (DCE) was monitored. Tetrachloroethene was reductively dechlorinated to trichloroethene, which again was dechlorinated at the same rate as DCE was produced. DCE showed a lag period of 40 h before transformation was observed. During normal reactor operation trans-1,2-DCE was the major DCE isomer, followed by cis-1,2-DCE. Small amounts of 1,1-DCE but no vinyl chloride were detected. When the influent tetrachloroethene concentration was increased from 4.6 μM to 27 μM, the transformation rate increased, indicating that the system was not saturated with tetrachloroethene. The main organic component in the effluent was acetate, indicating that the aceticlastic methane-producing bacteria were inhibited by the chlorinated ethenes.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 30 (1995), S. 1053-1058 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Lanthanum-transition metal mixed oxides, with the general formula La1−x M x BO3, have been prepared, whereinM stands for Ca and Sr, andB stands for one or more transition metals selected from the group consisting of Cr, Mn, Fe, Co and Ni, where 0⩽x⩽0.50. A drip pyrolysis method has been developed to synthesize the mixed oxides at low temperature (550
    Type of Medium: Electronic Resource
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