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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 395 (1982), S. 75-77 
    ISSN: 1432-2013
    Keywords: Excitation-contraction coupling ; Cell calcium ; Vascular smooth muscle ; Reversibly hyperpermeable cells ; Calcium indicators ; Aequorin ; Phenylephrine ; Angiotensin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The bioluminescent calcium indicator aequor in was successfully loaded into vascular smooth muscle cells ofAmphiuma tridactylum by either microinjection or a new method which makes the cells reversibly hyperpermeable. Both gave similar results; however, the latter method produced larger signals. Vasoconstrictors produced a sustained contraction and a light (calcium) response consisting of two component: a large transient followed by a smaller, sustained response. Electrical stimulation produced a light transient that was much briefer than the contraction. These results suggest that tension can be maintained in smooth muscle in the presence of lower calcium levels than those present during force development.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2013
    Keywords: Excitation-contraction coupling ; Cell calcium ; Mammalian cardiac muscles ; Reversibly hyperpermeable cells ; Calcium indicators ; Aequorin ; Isoproterenol ; Caffeine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The bioluminescent calcium indicator aequorin was successfully loaded into mammalian working myocardium of ferrets by a chemical procedure which makes the cells reversibly hyperpermeable through exposure to Ethylenebis-(oxyethylenenitrilo) tetraacetic acid (EGTA). After undergoing the loading procedure, developed tension at Lmax was 103±26% of the control, which indicates that the muscles regained normal function. The configurations of the aequorin signals (i.e., calcium transients) and their responses to drugs were the same as reported after microinjection of aequorin. The peak of the Ca++ transient determined by the method of fractional luminescence at 3s intervals of stimulation, 2.5mM [Ca++]o, 22.5°C was 1.1μM; this value is similar to that reported for microinjection. These results indicate that the chemical loading procedure is a useful alternative to microinjection for loading aequorin into mammalian working myocardium.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2013
    Keywords: Aequorin ; Calcium indicators ; Cyanide ; Hypoxia ; Ferret ; Oxidative phosphorylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We used the bioluminescent Ca2+ indicator, aequorin to record intracellular calcium transients during reoxygenation of hypoxic ferret ventricular muscle in order to determine whether alterations in the amplitude and time course of isometric contraction are emdiated by changes in [Ca2+]i. Papillary muscles ≤1 mm in diameter were removed from the hearts of male ferrets and perfused with a bicarbonate-buffered physiologic salt solution at 30°C. Muscles were stimulated to contract isometrically at 0.33 Hz and were loaded with aequorin by a chemical procedure. Hypoxia was induced by changing the gas mixture bubbling the perfusate to 95% N2, 5% CO2; reoxygenation was accomplished by switching the gas mixture to 95% O2, 5% CO2. Hypoxia produced a decrease in peak Ca2+ and tension that was reversed by reoxygenation. However, the effects on tension of changes in oxygenation were greater than expected from the degree of change in [Ca2+]i. The time courses of the Ca2+ transient and isometric twitch moved in opposite directions and were respectively prolonged/abbreviated by hypoxia and abbreviated/prolonged by reoxygenation. These results indicate that changes in the amplitude and time course of the isometric twitch induced by hypoxia and reoxygenation cannot be attributed alone to changes in intracellular Ca2+ availability and are caused in part by a significant decrease in the calcium sensitivity of the contractile apparatus.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 8 (1962), S. 593-598 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the course of research the authors have collected a number of transfer functions for various types of heat exchangers. For the convenience of analysis the heat exchangers may be classified into several basic types described in subsequent pages. In each case certain assumptions are made when one writes down the differential equations of the heat exchanger, which constitute the so-called mathematical model of the exchanger. If a particular heat exchanger is being classified, it is important to know the nature of temperature variation and the relative directions of flow of the exchanging fluid streams. If the heat exchanger in question matches one of the types described, then the transfer functions listed may be used to obtain its theoretical frequency and transient responses.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 3 (1957), S. 313-317 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A simple expression for estimating the turbulent forced-convection heat transfer performance of liquid metals flowing through noncircular ducts is presented. This equation requires the knowledge of the slug Nusselt number evaluated for the specific geometry and for the pertinent boundary conditions. Such Nusselt values are presented herein for a number of technically important geometries. One check on the heat transfer prediction given by Equation (4) is in the case of an annular duct with constant heat flow through the outer wall with the inner wall insulated, for which experimental data exist. The prediction agrees within 20% with the experimental data.Several possible boundary conditions that may exist in noncircular cross sections are throughly discussed, and it is hoped that as a result this paper may serve to clarify some of the confusion existing in the literature.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 4 (1958), S. 211-217 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The experimental apparatus and procedures which were developed for the determination of the heterogeneous phase behavior of the methane-hydrogen sulfide system have been described in a previous paper (2). The apparatus and procedures were tested and employed at temperatures in the range of  - 300 to 300°F. and at pressures up to 2000 1b./sq. in. abs. The vapor-liquid, vapor-solid, liquid-vapor-solid, liquid-liquid-vapor and liquid-liquid-solid phase border curves were determined for six mixtures of methane and hydrogen sulfide. The phase compositions were determined at selected points along the three-phase univariant equilibrium lines. An invariant point (quadruple point) was found which involves the equilibrium of two liquid phases, a vapor phase, and a solid phase. These data are presented on P-T and T-X diagrams.The data contribute to the understanding of phase behavior of light hydrocarbons containing hydrogen sulfide.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 7 (1961), S. 514-518 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The phase behavior of the methane-n-heptane system was determined at temperatures from -200° to 340°F. at pressures up to 1,500 lb./sq. in. abs. The system was found to have a miscibility gap in the liquid-vapor region. The compositions of phases along the three phase (L1 - L2 - V) locus indicate that the L1 phase is approximately 0.64 mole fraction methane and that the L2 and V phases are substantially pure methane phases. The quadruple point (L1 - L2 - S1 - V) was found at a temperature of -154.4°F. and a pressure of 339 lb./sq. in. abs. A singular point (type k) at which the L2 phase is in critical identity with the vapor phase was found at -114.6°F. and at a pressure of 694 lb./sq. in. abs.The fugacity of methane at constant temperature as a function of the composition of dissolved methane was found to be linear in the low-temperature range. The plot of Henry's law constant expressed as fugacity mole fraction methane ratio vs. reciprocal absolute temperature was linear in the temperature range from -130° to approximately 100°F. These data indicate that the solution thermodynamics of methane-n-heptane is particularly simple in the low-temperature range.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 19 (1973), S. 1140-1149 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The stability of crystal-size distribution (CSD) in the classified product crystallizer with fines removal was investigated using spectral techniques to determine stable solutions of the linearized population balance. The model used to describe the crystallizer assumed rapid growth kinetics (high yield), magma-dependent secondary nucleation, and recycle of dissolved fines. Fines removal and classified product removal were characterized in the model by piece-wise constant removal rates (R - 1) and z times the MSMPR removal rate, respectively.Stability regions were presented as critical values of the kinetic nucleation/growth rate exponent i = d(log B°)/d(log G) versus dimensionless parameters of the system. The parameters which influence CSD stability were maximum fines size and removal rate, product classification size and removal rate, and the magama-characterizing exponent in the nucleation expression. Whether or not dissolved fines are recycled directly back to the crystal magma also influences stability.
    Additional Material: 11 Ill.
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