Electrochemical aptamer-based devices are of interest in an approach in which this quantity is adjusted in a "feedback-based" manner. Studies that estimate a range for this quantity may rely on the "continual reassessment approach." In a "3+3 design," this quantity is first "escalated" then "expanded" to determine a quantity called the R2PD. This quantity has traditionally, but questionably been calculated based on a patient's body surface (*) area for chemotherapeutics. (-5[1])Curves describing the relation between tissue response and this quantity typically follow the Hill equation. (10[1])Phase 1 studies typically aim to establish the "maximum tolerated" value of this quantity. The toxicity of a xenobiotic can be expressed as the value of this quantity at which it is lethal (10[1])to 50% of patients. For 10 points, name this quantity that describes how much of a drug is administered to a patient. ■END■