Hey JedKampe, There are numerous drugs and conditions that can cause a false positive for cocaine not to mention human error. Substances that can cause a false positive drug test result: Amoxicillin is an antibiotic in the penicillin group of drugs. It fights bacteria in your body. Ampicillin is another antibiotic similar to amoxicillin.
When the nerve is damaged,the action potential remains between the electrodes and doesn't reach the second electrode (i.e potential difference remains positive and doesn't go into negative phase) , the biphasic action potential changes into monophasic action potential i.e with single phase. Source(s):E: biphasic action potential change into the monophasic action? Why does the biphasic action potential change into the monophasic action potential after nerve injury between the two recording electrodes?
A cyclic nucleotide, adenosine 3',5'-cyclic monophosphate, that serves as an intracellular and, in some cases, extracellular second messenger  mediating the action of many peptide or amine hormones. The nucleotide binds to cAMP-dependent kinases and releases free (catalytically active) subunits.