Activation Mechanisms

Subsequent studies (63,64) suggested that the nature of the chemical activation process was a one-electron oxidation of the fluorescer by (27) followed by decomposition of the dioxetanedione radical anion to a carbon dioxide radical anion. Back electron transfer to the radical cation of the fluorescer produced the excited state which emitted the luminescence characteristic of the fluorescent state of the emitter. The chemical activation mechanism was patterned after the CIEEL mechanism proposed for dioxetanones and dioxetanes discussed earher (65). Additional support for the CIEEL mechanism, was furnished by demonstration (66) that a linear correlation existed between the singlet excitation energy of the fluorescer and the chemiluminescence intensity which had been shown earher with dimethyl dioxetanone (67). 

Carboximide, trichloromethylthio-biocidal activity mechanism, 1, 400-401 fungicide, 1, 399 Carboximides... 

Copper(II), di-/Lt-bromobis[bromo(pyridine)-structure, 2, 108 Copper 8-hydroxyquinolinate biocidal activity mechanism, 1, 401 fungicide, 1, 399 Copper nitrotetrazole as propellants, 5, 837 Copper phthalocyanine, 1, 333-334 colour and constitution, 1, 345 Coproporphyrin, 4, 382 Coproporphyrin, dehydro-, 4, 382... 

Quaternary ammonium compounds biocidal activity mechanism, 1, 401 toxicity, 1, 124 Quaternization heterocyclic compounds reviews, 1, 73 ( )-Quebrach amine synthesis, 1, 490 Queen substance synthesis, 1, 439 4, 777 Quercetin occurrence, 3, 878 pentamethyl ether photolysis, 3, 696 photooxidation, 3, 695 Quercetrin hydrolysis, 3, 878 Quinacetol sulfate as fungicide, 2, 514 Quinacridone, 2,9-dimethyl-, 1, 336 Quinacridone pigments, 1, 335-336 Quinacrine... 

Sigler, P.B., et al. Structure of crystalline a-chymotrypsin II. A preliminary report including a hypothesis for the activation mechanism. /. Mol. Biol. 35 143-164, 1968. 

Studies on the oxygen activation mechanisms by new heme enzymes using hemoprotein mutants and synthetic heme models 96YGK1046. 

The aim of heat recovery is to avoid wastage of any quantity of heat or cold energy which has been generated within a system. Methods of recovery may be passive or active. Mechanical heat recovery systems will generally be found under the description of Heat Pumps. 

Original Strnctnre and Activation Mechanism of mGIn Receptors... 

Inside the typical smooth muscle cell, the cytoplasmic filaments course around the nuclei filling most of the cytoplasm between the nuclei and the plasma membrane. There are two filamentous systems in the smooth muscle cell which run lengthwise through the cell. The first is the more intensively studied actin-myosin sliding filament system. This is the system to which a consensus of investigators attribute most of the active mechanical properties of smooth muscle. It will be discussed in detail below. The second system is the intermediate filament system which to an unknown degree runs in parallel to the actin-myosin system and whose functional role has not yet been completely agreed upon. The intermediate filaments are so named because their diameters are intermediate between those of myosin and actin. These very stable filaments are functionally associated with various protein cytoarchitectural structures, microtubular systems, and desmosomes. Various proteins may participate in the formation of intermediate filaments, e.g., vimentin. 

Finally, if the phosphorylation of myosin is the activation mechanism, then dephosphorylation is likely to be the deactivation mechanism, and so it seems. However, there are several myosin phosphatases in smooth muscle cells and they have some range of substrate specificities. Thus, there are several possible candidates for a regulatory role. 

Study of the action of AR on . coli precA luxCDABE-Anvp has confirmed it photoprotective effects and has shown features of such activity in live systems. Surprising was the interrelation between preservation of viability of AR-processed bacterial cells in the conditions of a long and intensive UV-irradiation and depression of activity their reparing SOS-systems. It has assumed AR action and the SOS-answer as alternative "passive" and "active" mechanisms for protection of bacterial cells DNA at various intensivity of UV-irradiation. 

This chapter highlights the mechanisms responsible for mast cell activation during anaphylactic responses to environmental substances. In addition to discussing in detail the activation of mast cells and basophils by IgE and antigen, we also will describe how mouse models have been used to analyze the importance of various proteins, cells, mediators and activation mechanisms in the expression of anaphylaxis in that species. 

Various passive and active mechanisms are employed to maintain gradients of such molecules across different membranes. 

Firstly, the difference between ethane and higher alkanes cannot be readily explained by mechanisms such as those proposed by Gault (Scheme 38) or 1,2-carbon-carbon activation mechanisms (Scheme 39), while the mechanism involving y-H activation does fully account for this observation. Given... 

Viscoelastics Certain silicone elastomers undergo changes in shear modulus under the influence of electric fields, which might be useful in active mechanical damping applications. 

Antioxidant Activities of Synthetic Indole Derivatives and Possible Activity Mechanisms... 

The Ar-O-R aromatic ethers can give rise to reactions of electrophilic substitution that can be dangerous not only because of the reagents nature but also the activation effect due to the active oxygen. The activation mechanism can be described in the same way as for phenols. 

In the lattice-gas model, as treated in Section IV.D above, ion transfer is viewed as an activated process. In an alternative view it is considered as a transport governed by the Nernst-Planck or the Langevin equation. These two models are not necessarily contra-dictive for high ionic concentrations the space-charge regions and the interface have similar widths, and then the barrier for ion transfer may vanish. So the activated mechanism may operate at low and the transport mechanism at high ionic concentrations. 

The fair agreement of expressions (2.67) and (2.71) with experimental data as well as agreement of independently obtained experimental data concerning kinetics of the change of a with the data on equilibrium enabled the author of paper [89] to conclude that the proposed mechanism of effect of hydrogen on electric conductivity of semiconductors can be one of active mechanisms. The heat of total reaction (2.63) calculated from the values found was about 4.6 kcal. 

Charging by contact electrification is an active mechanism whenever dissimilar particles make and break contact with each other, or whenever they slide over a chute or an electrode. This charging mechanism is most frequently used to charge selectively and obtain an electrostatic separation of two species of dielectric materials as realized in a free fall electrostatic separator. 

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