Post-distribution half-life

In Figure 10.30 the survival rate of the total sedimentary mass for the different Phanerozoic systems is plotted and compared with survival rates for the total carbonate and dolomite mass distribution. The difference between the two latter survival rates for each system is the mass of limestone surviving per unit of time. Equation 10.1 is the log linear relationship for the total sedimentary mass, and implies a 130 million year half-life for the post-Devonian mass, and for a constant sediment mass with a constant probability of destruction, a mean sedimentation rate since post-Devonian time of about 100 x 1014 g y 1. The modem global erosional flux is 200 x 1014 g y-1, of which about 15% is particulate and dissolved carbonate. Although the data are less reliable for the survival rate of Phanerozoic carbonate sediments than for the total sedimentary mass, a best log linear fit to the post-Permian preserved mass of carbonate rocks is... 

In order to target drug delivery, it is very important to study the distribution of the drug within the body. For example radiolabelling of the anticancer complex [Ru (r 6-fhiorene)Cl(en)]PF6 with the (3-emitter 106Ru (half-life = 1.01 y) has allowed its biodistribution to be studied 0.25 h post i.v. injection at a dose of 25 mg kg-1, 106Ru is well distributed throughout the tissues of a rat [155]. 

Determination of the elimination half life (fi/a), the elimination rate constant (K oiKd) and the apparent volume of distribution (V) from post-infusion (i.e. following the cessation of infusion) concentration versus time data and from concentration versus time data obtained during infusion. 

Use of post-infusion plasma concentration data to obtain half life, elimination rate constant and the apparent volume of distribution... 

Half life, elimination rote constant and the apparent volume of distribution from the post-infusion data and by the graphical method... 

Determination of post-distribution (or slow disposition, or terminal) half life (ti/z)/ and its corresponding rate constant (/3). 

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