Results 211 to 220 of about 248,354 (262)
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Infusion at constant rate in vivo
Experientia, 1978Infusion can be maintained at a constant rate over an extended period of time in vivo by the use of an implanted diffusion chamber. Plasma 59Fe was maintained at a constant level for 10 days when infused from a s.c. implant. Injected isotope was cleared exponentially with a half-clearance time of about 8 h.
J K, Gong, C, DeLuca
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On the Fallacy of Constant Extinction Rates
Evolution, 1982Van Valen's "new evolutionary law" (Van Valen, 1973) has provoked considerable discussion of taxonomic survivorship curves (for a review, see Van Valen, 1976; Hallam, 1976) and of the Red Queen hypothesis (Maynard Smith, 1976; Stensith, 1979). Despite allegations that the linearity of Van Valen's curves may be an artifact of his method of survivorship ...
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When Rate Constants Are Not Enough
The Journal of Physical Chemistry A, 2015Real-world chemical systems consisting of multiple isomers and multiple reaction channels often react significantly prior to attaining a steady state energy distribution (SED). Detailed elementary reaction models, which implicitly require SED conditions, may be invalid when non-steady-state energy distributions (NSED) exist.
John R, Barker +2 more
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Fluorodeoxyglucose rate constants, lumped constant, and glucose metabolic rate in rabbit heart
American Journal of Physiology-Heart and Circulatory Physiology, 1987The isolated arterially perfused rabbit interventricular septum was used to measure myocardial metabolic rate for glucose (MMRGlc) and rate constants and lumped constant (LC) for the glucose analogue [18F]fluorodeoxyglucose (FDG) using a tracer kinetic model.
J, Krivokapich +3 more
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On reaction rate constants and rate kernels
Chemical Physics Letters, 1978Abstract A simple model for a reversible isomerization reaction A ⇋ B is used to show how rate constants and their time-dependent generalizations can be related to microscopic reactive steps and nonreactive internal dynamics (e.g., vibrational relaxation).
Scott H. Northrup, James T. Hynes
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2023
This chapter considers the properties of rate constants. First, it distinguishes between the rate at which reactants encounter each other from the rate at which they undergo change once they have met. The very important feature of the latter step is the dependence of the relevant rate constant on temperature, which is found in most cases to obey an ...
Peter Atkins +3 more
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This chapter considers the properties of rate constants. First, it distinguishes between the rate at which reactants encounter each other from the rate at which they undergo change once they have met. The very important feature of the latter step is the dependence of the relevant rate constant on temperature, which is found in most cases to obey an ...
Peter Atkins +3 more
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The load dependence of rate constants
The Journal of Chemical Physics, 2008As experimental techniques in biophysics have progressed at the single molecule level, there has been considerable interest in understanding how external mechanical influences (such as load) affect chemical reactions. The majority of biophysical studies investigating load-dependent kinetics use an equation where the rate constant exponentially depends ...
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2018
This chapter assesses the methods used to study the thermodynamics and kinetics of chemical reactions based on quantum chemistry, molecular mechanics and statistical mechanics. Statistical thermodynamics can be used to calculate thermodynamic properties such as relative free energies based on properties of the potential energy surface V(R).
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This chapter assesses the methods used to study the thermodynamics and kinetics of chemical reactions based on quantum chemistry, molecular mechanics and statistical mechanics. Statistical thermodynamics can be used to calculate thermodynamic properties such as relative free energies based on properties of the potential energy surface V(R).
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CODATA Recommended Values of the Fundamental Physical Constants: 2018
Reviews of Modern Physics, 2021David B. Newell +2 more
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