Reversible and irreversible alterations of the optical thickness of PQ/PMMA volume recording media samples. Part 2: mathematical modeling.

A theoretical study of phenanthrenequinone-doped polymethyl methacrylate (PQ/PMMA) samples parameter changes during irradiation is presented. The research has been carried out on the basis of the experimental study (Part 1, [Appl. Opt.

Reversible and irreversible alterations of the optical thickness of PQ/PMMA volume recording media samples. Part I: Experiment.

Experimental research into changes of the optical thickness of phenanthrenequinone-doped polymethyl methacrylate samples in the process of irradiation by a 473 nm laser is presented. It was demonstrated that heating-induced reversible changes lead to a decrease in the optical thickness. The temperature coefficient of the relative changes of the optical thickness was measured to be -1.

[Allosteric effect of serotonin and mianserin on the kinetics of specific [3H]-ligand binding to adrenergic and muscarinic receptors in the rat cerebral cortex membranes].

The effects of serotonin receptor activation (by serotonin) and inhibition (by mianserin) on the properties of the α1-, α2-adrenoreceptors, and muscarinic cholinergic receptors in subcellular membrane fractions from the rat cerebral cortex were studied. Experimental data on the kinetics of specific antagonists binding to adrenergic and muscarinic receptors were analyzed by graphical and mathematical methods. The results suggest the presence of allosteric (cross-talk) interaction.

[Intracellular transmission of the cholinergic signal in the chick amnion].

The role of the system of deposited calcium in the mediation of contractile reactions to carbachol in an isolated amnion of 11-13 day old chicken embryo was studied. It was found that thapsigargin (2 microM, 20 min), an inhibitor of the endoplasmic reticulum Ca2+ -ATPases, decreases the tonic reaction to carbachol by 40 +/- 2%. In the presence of U73122 (5-10 microM, 10 min), a phosphoinositide-specific phospholipase C inhibitor, the rhythmic contractile reaction of the amnion to carbachol is blocked, whereas the tonic reactiondecreases to 47 +/- 9% of the initial one.

[Similarities and differences in the effect of cocaine on alpha-adrenergic and muscarinic response].

Similarities and differences in the effect of cocaine on alpha-adrenergic and muscarinic receptors were shown in three experimental models. The postsynaptic stimulating effect of cocaine through activation of alpha-adrenergic receptors was found in a chicken embryo without innervation and in an innervated rat vas deferens. Cocaine caused an increase of the amount of activated alpha-adrenergic receptors and the appearance of an additional receptor pool and changed their dimerization level.