Ultrafast time domain demonstration of bulk magnetization precession at zero magnetic field ferromagnetic resonance induced by terahertz magnetic field.

We report the first observation of sub-terahertz bulk-magnetization precession, using terahertz time-domain spectroscopy. The magnetization precession in gallium-substituted epsilon-iron oxide nano-ferromagnets under zero magnetic field is induced by the impulsive magnetic field of the THz wave through the gyromagnetic effect. Just at the resonance frequency, the linear to circular polarized wave conversion is realized. This is understood as the free induction decay signal radiated from a rotating magnetic dipole corresponding to the natural resonance. Furthermore, this demonstration reveals that the series of gallium-substituted epsilon-iron oxide nano-ferromagnets is very prospective for magneto-optic devices, which work at room temperature without external magnetic field, in next-generation wireless communication.

Postoperative treatment of carvedilol following low dose landiolol has preventive effect for atrial fibrillation after coronary artery bypass grafting.

BACKGROUND: Postoperative atrial fibrillation (AF) is the most common complication after coronary artery bypass grafting (CABG). We have reported that the intra- and perioperative administration of landiolol has a preventive effect on postoperative AF in the early postoperative period after CABG surgery. The purpose of this study was to investigate the prophylactic effect of postoperative treatment with carvedilol following landiolol against postoperative AF. METHODS: We reviewed all patients who underwent CABG from December 2005 and February 2009. Fifty-three patients underwent scheduled isolated CABG and were divided two groups; carvedilol group (n = 31), and control group (n = 22). Incidences of postoperative AF were noted. RESULTS: There was no statistical difference between the two groups with regard to the occurrence of AF after CABG. The maximum ventricular rate of AF was significantly lower in the carvedilol group than in the control group. All patients with AF in the control group needed treatment for tachycardia, but this was not necessary in the carvedilol group. CONCLUSIONS: Postoperative treatment with carvedilol following landiolol has the effect of preventing tachycardia during AF after coronary artery bypass grafting.