Kinetics of activation

One of the most important parameters of an immobilized-carrier complex is stability of its activity. Catalytic activity of the complex diminishes with time because of leakage, desorption, deactivation, and the like. The half-life of the complex is often used to describe the activity stabihty. Even though there may be frequent exceptions, hn-ear decay is often assumed in treating the kinetics of activity decay of an immobilized complex. 

In deriving the kinetics of activation-energy controlled charge transfer it was emphasised that a simple one-step electron-transfer process would be considered to eliminate the complications that arise in multistep reactions. The h.e.r. in acid solutions can be represented by the overall equation ... 

Tankersley DL, Finlayson JS Kinetics of activation and autoactivation of human factor XII. Biochemistry 1984 23 273-279. 

The molecular species responsible for lucigenin chemiluminescence are not fully defined. Because this probe does not permeate the cell, only secreted oxidants are detected. Several reports have suggested that this probe measures O2 secretion or else H2O2 secretion on the other hand, some evidence indicates that this cannot be so. Certainly, the oxidant(s) detected by lucigenin is dependent on O2 formation, but the kinetics of activated 02" and H2O2 formation by neutrophils do not parallel those of lucigenin chemiluminescence. Thus, this probe is at least an indirect measure of O2 secretion. 

Bockris JOM (1956) Kinetics of activation controlled consecutive electrochemical reactions anodic evolution of oxygen. J Chem Phys 24 817-827... 

Lamb, T.D. Gain and kinetics of activation in the G-protein cascade of phototransduction (1996) Proc. Natl. Acad. Sd. U.S.A. 93, 566-570... 

Aharoni, C, and Ungarish, M. (1976). Kinetics of activated chemisorption. I. The non-Elovichian part of the isotherm. J. Chem. Soc., Faraday Trans. 72, 400-408. 

C. Kinetics of Active Metal Electrodes Covered by Surface Films Current-Potential Relationship... 

The energetic nonuniformity of catalytically active nickel oxide was investigated by Refer (161). The kinetics of activated adsorption was studied under constant pressure at several temperatures and the data were described by the expression... 

A model for the redox chemistry of the Ni site based on redox titrations of H2ase is summarized in Figure 1. Ni,Fe H2ases are generally isolated in air as a combination of two fully oxidized and inactive forms that can be distinguished by their Ni EPR spectra and their kinetics of activation. Form A (g = 2.31, 2.23, and 2.02) requires extensive incu-... 

The hysteresis loop is considered a dynamic property because the kinetics of activated processes should depend on the observation time. The limit of long observation times is important in geophysics for simulating processes occurring over geological time scales. Kinetics experiments are the most important tool in this respect because the study of hysteretic transitions is otherwise limited to measurements taken under nonequilibrium conditions. 

Kinetics of Activation Analysis. The time scale of the measurement is determined by the half-life of the radionuclides produced it is often nearly optimal to irradiate for one half-life, wait one half-life, and count for one half-life. 

Gubitosi-Klug RA, Gross RW. Fatty acid ethyl esters, nonoxidative metabolites of ethanol, accelerate the kinetics of activation of the human brain delayed rectifier K channel, Kv 1.1. J Biol Chem 1996 271 32,519-32,522. 

Barone FE, Tansey MR. Isolation, purification, identification, synthesis, and kinetics of activity of the anticandidal component of Allium sativum and a hypothesis for its mode of action. Mycologia 1977 69 793-825. 

Those catalysts whose kinetics of activation are to be studied have to display time-on-stream-dependent kinetics of activation if these are to be studied in a TS-PFR. At this time no other kinetics of activation can be unraveled using available TS-PFR theory. The procedures to be used are similar to those described below in the section on catalyst decay. 

Two approaches are mainly responsible for the discovery of the rich diversity of voltage-dependent Ca channels. On the one hand, the characterization of the biophysical properties of Ca channels (kinetics of activation, inactivation and deactivation, voltage-range for activation, and conductance), both at the single-channel and at the whole-cell level has been possible, thanks to the improvement of the patch-clamp techniques [32], On the other hand, the isolation, purification, and synthesis of different neurotoxins have provided ligands with remarkable discrimination for different subtypes of high-threshold DHP-resistant Ca " channels [2],... 

Vergote J, Moretti J, de Vries EGE and Gamier-Suillerot A. Comparison of the kinetics of active efflux of 99mTc-MIBI in cells with P-glycoprotein-mediated and multidrug- resistance protein-associated multidrug-resistance phenotypes. Eur J Biochem 1998 252 140-146. 

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