There are two models of protein folding that are currently being confirmed: 1  The diffusion collision model, in which a nucleus is formed, then the secondary structure is formed, and finally these secondary structures are collided together and pack tightly together.
ATT Validity Dates. 1  Each ATT is valid for a period of time specified by the BON/RB (the average length of an ATT is 90 days). 2  Once the BON/RB has declared you eligible to test and you receive your ATT, you must test within the validity dates on the ATT.
1 You should plan to arrive at the test center at least 30 minutes before your testing time. If you are more than 30 minutes late, you may be required to forfeit your NCLEX appointment and will be required to reregister and pay another exam fee.  Occasionally, technical problems may require rescheduling of your exam.