The objective of this study was to evaluate how the vehicles of choice affect the pharmacokinetics of orally administered Fluoranthene [FLA] in rats. Fluoranthene is a member of the family of Polycyclic Aromatic Hydrocarbon chemicals. Fluoranthene exposure to humans may occur as a result of cigarette smoking, consumption of contaminated food and water, heating woods in stoves and boilers, indus...

Despite the broad use of enzymes in electroanalytical biosensors, the influence of enzyme kinetics on the function of prototype sensors is often overlooked or neglected. In the present study, we employ amperometry as an alternative or complementary method to study the kinetics of tyrosinase, whose catalytic activity results in o-quinone products. We further compare our results for four monophen...

The interaction of RNAs and their ligands strongly depends on folding kinetics and thus requires explanations that go beyond thermodynamic effects. Whereas the computational prediction of minimum energy secondary structures, and even RNA–RNA and RNA–ligand interactions, are well established, the analysis of their kinetics is still in its infancy. Due to enormous conformation spaces, the exact a...

One of the most recent applications of classical linear response theory is to Lecture 7 10/13/09 the theory of chemical reaction rate constants, although this is one of the more important and interesting applications of time dependent statistical mechanics, from a chemistry point of view. At first glance it looks like an unusual and unphysical way of constructing a theory, but in fact it is valid.

Although senescence is a defining property of euploid mammalian cells, its physiologic basis remains obscure. Previously, cell kinetics properties of normal tissue cells have not been considered in models for senescence. We now provide evidence that senescence is in fact the natural consequence of normal in vivo somatic stem cell kinetics extended in culture. This concept of senescence is based...

For decades the interaction of the anticholinesterase organophosphorus compounds with acetylcholinesterase has been characterized as a straightforward phosphylation of the active site serine (Ser-203) which can be described kinetically by the inhibitory rate constant k(i). However, more recently certain kinetic complexities in the inhibition of acetylcholinesterase by organophosphates such as p...

We have studied the effect of Rb+ on K channel closing kinetics in toadfish pancreatic islet cells. These channels are voltage dependent, activating at voltages positive to -10 mV. The channels also inactivate upon prolonged depolarizations, and the inactivation time course is best fit by the sum of two exponentials. Instantaneous current-voltage relationships show that external Rb+ enters the ...

Experiments were carried out in which the dependence of the fractional softening on temperature, time and strain rate was determined in a 304H stainless steel. Three prestrain ranges were identified pertaining to three different post-deformation softening behaviors: 1) prestraining to below the DRX critical strain: strongly strain dependent softening by SRX alone with softening kinetics control...

The adsorption properties and mechanics of selected endocrine disrupting compounds; 17 β-estradiol, 17 α – ethinylestradiol and bisphenol A on locally available black tea leaves waste and granular activated carbon were investigated. The results obtained indicated that the kinetics of adsorption were pH, adsorbent dose, contact time and temperature dependent with equilibrium being reached at 20 ...

In the present work, the drying of calcium carbonate in a batch spouted bed dryer with inert particles has been investigated experimentally. The effect of several operating parameters including air temperature (90, 100, and 110 ˚C), air velocity (Ums, 1.2 Ums, and 1.5 Ums), and dry solid mass (5, 10, 20 g) has been studied. The Taguchi method has been applied to determine the optimal parameters...