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. An adaptive stress response is often responsible for a biphasic response to this quantity, a phenomenon called (*) hormesis. Curves describing the relation between tissue response and this quantity typically follow the Hill equation. Phase 1 studies typically aim to establish the "maximum tolerated" (10[1])value of this quantity. (10[1])The toxicity of a xenobiotic can be expressed as the value of this quantity at which it is lethal to 50% of patients. For 10 points, name this quantity that describes how much of a drug is administered to a patient. ■END■