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Aim: To investigate the effects of peripheral orexins on myoelectric activity of the sphincter of Oddi (SO) in fasted rabbits, and carry out a preliminary investigation into the mechanisms underlying these effects. Methods: Myoelectric activity of SO in fasted rabbits was recorded before and after intravenous or local application of orexins. The effects of intravenous atropine on orexin-increased myoelectric activity of SO were tested. Results: Myoelectric activity of SO was activated by both intravenous and local injection of orexin-A or orexin-B. Intravenous application of atropine completely inhibited the excitatory effect of orexins on SO. Conclusion: Peripheral application of orexins can increase myoelectric activity of SO in fasted rabbits, which is partially associated with the activation of the cholinergic pathway. [ABSTRACT FROM AUTHOR]

The influence of labyrinth seal on the stability of unbalanced rotor system was presented. Under the periodic excitation of rotor unbalance, the whirling vibration of rotor is synchronous if the rotation speed is below stability threshold, whereas the vibration becomes severe and asynchronous which is defined as unstable if the rotation speed exceeds threshold. The Muszynska model of seal force and shooting method were used to investigate synchronous solution of the dynamic equation of rotor system. Then, based on Floquet theory the stability of synchronous solution and unstable dynamic characteristic of system were analyzed. [ABSTRACT FROM AUTHOR]