Plastic deformation down to 4.2 K of CoO single crystals and T.E.M. observation of dislocations

Plastic deformation of CoO has been performed at 4.2 K by compression of single crystals along . The influence of thermodynamic conditions of specimen preparation has been shown. The dislocation structure observed by transmission electron microscopy (TEM) is not directly related to the one existing during deformation at very low temperature.On a déformé plastiquement CoO à 4,2 K par compression de monocristaux le long de . L'influence des conditions thermodynamiques de préparation des échantillons a été montrée. La structure des dislocations observée en microscopie électronique en transmission (TEM) n'est pas directement reliée à celle existant pendant la déformation à très basse température

Quantitaton of rate of gastrointestinal and buccal absorption of acidic and basic drugs based on extraction theory

Equations have been derived which quantitatively describe the rate of gastrointestinal and buccal absorption of acidic and basic drugs as a function of pH of aqueous lumenal contents and time. The equations have been used to fit observed data in the literature, and the estimated parameters are reported. An equation which describes the renal clearance of an acidic or basic drug as a function of urinary pH is also derived. In essence, the equations quantitate the pH-partition hypothesis and explain most, if not all, related observed data in the literature. The results suggest that the aqueous diffusion layer may not rate-limit absorption of monomeric drug molecules but that absorption is rate-limited by transfer of drug out of the membrane in vivo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45024/1/10928_2005_Article_BF01060026.pd