The periodic time modulations, found recently in the two-body orbital electron capture (EC) decay of both, hydrogen-like Pr-140(58+) and Pm-142(60+) ions, with periods near to 7 s and amplitudes of ...about 20%, were re-investigated for the case of Pm-142(60+) by using a 245 MHz resonator cavity with a much improved sensitivity and time resolution. We observed that the exponential EC decay is modulated with a period T = 7.11(11) s, in accordance with a modulation period T = 7.12(11) s as obtained from simultaneous observations with a capacitive pick-up, employed also in the previous experiments. The modulation amplitudes amount to a(R) = 0.107(24) and a(P) = 0.134(27) for the 245 MHz resonator and the capacitive pick-up, respectively. These new results corroborate for both detectors exactly our previous findings of modulation periods near to 7 s, though with distinctly smaller amplitudes. Also the three-body beta(+) decays have been analyzed. For a supposed modulation period near to 7 s we found an amplitude a = 0.027(27), compatible with a = 0 and in agreement with the preliminary result a = 0.030(30) of our previous experiment. These observations could point at weak interaction as origin of the observed 7 s-modulation of the EC decay. Furthermore, the data suggest that interference terms occur in the two-body EC decay, although the neutrinos are not directly observed. (C) 2013 Elsevier B.V. All rights reserved.
Ischemic brain damage has been reported in healthy patients after beach chair position for surgery due to cerebral hypoperfusion. Near-infrared spectroscopy has been described as a non-invasive, ...continuous method to monitor cerebral oxygen saturation. However, its impact on neurobehavioral outcome comparing different anesthesia regimens has been poorly described.
In this prospective, assessor-blinded study, 90 patients undergoing shoulder surgery in beach chair position following general (G-group, n=45) or regional anesthesia (R-group; n=45) were enrolled to assess the prevalence of cerebral desaturation events comparing anesthesia regimens and their impact on neurobehavioral and neurological outcome. Anesthesiologists were blinded to regional cerebral oxygen saturation values. Baseline data assessed the day before surgery included neurological and neurobehavioral tests, which were repeated the day after surgery. The baseline data for regional cerebral oxygen saturation/bispectral index and invasive blood pressure both at heart and auditory meatus levels were taken prior to anesthesia, 5 min after induction of anesthesia, 5 min after beach chair positioning, after skin incision and thereafter all 20 min until discharge.
Patients in the R-group showed significantly less cerebral desaturation events (p<0.001), drops in regional cerebral oxygen saturation values (p<0.001), significantly better neurobehavioral test results the day after surgery (p<0.001) and showed a greater hemodynamic stability in the beach chair position compared to patients in the G-group.
The incidence of regional cerebral oxygen desaturations seems to influence the neurobehavioral outcome. Regional anesthesia offers more stable cardiovascular conditions for shoulder surgery in beach chair position influencing neurobehavioral test results at 24h.
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