Amale client is diagnosed with heart failure. the health care provider orders a loading dose of digoxin. loading doses are necessary for what reason?

a) digoxin's long half-life makes therapeutic serum levels difficult to obtain without loading.
b) the client is at risk for dysthymia with titrated doses.
c) oral digoxin is ineffective for the treatment of heart failure.
d) digoxin's short half-life increases the risk for toxicity.

Investigator a has biological specimens that are coded and linked to identifiers of the source individuals. investigator a provides the specimens to investigator b but does not provide the individual identifiers. investigator b agrees not to re-identify the source individuals. is investigator b's research using the biospecimens human subjects research according to the definition of human subjects research in the federal regulations?