ABSTRACT
Searches for the lepton number violating K^{+}âπ^{-}µ^{+}e^{+} decay and the lepton flavor violating K^{+}âπ^{+}µ^{-}e^{+} and π^{0}âµ^{-}e^{+} decays are reported using data collected by the NA62 experiment at CERN in 2017-2018. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: B(K^{+}âπ^{-}µ^{+}e^{+})<4.2×10^{-11}, B(K^{+}âπ^{+}µ^{-}e^{+})<6.6×10^{-11} and B(π^{0}âµ^{-}e^{+})<3.2×10^{-10}. These results improve by 1 order of magnitude over previous results for these decay modes.
ABSTRACT
The aim of the study was to investigate if epidural analgesia may affect the operative vaginal birth rate. An observational study was carried out on 1,158 in low-risk patients who delivered vaginally; 46.9% of these patients underwent epidural analgesia using different doses and drugs. Overall, epidural analgesia enhanced the probability of vacuum delivery (OR 2.70 95% CI 1.88-3.89, p < 0.001). Vacuum application was increased about seven times by administration of fentanyl alone at the first dose, while it was reduced if ropivacaine was added to fentanyl. In patients undergoing epidural analgesia, increasing the amount of ropivacaine at the first dose reduced the probability of vacuum delivery (OR 0.82; 95% CI 0.67-1.00, p = 0.05). Moreover, increasing the number of top-ups reduced the probability of vacuum delivery (OR 0.49 95% CI 0.27-0.93, p = 0.029) and the time of the second stage of labor. On the other hand, increasing time from the first dose of epidural to the last top-up increased the risk of operative vaginal delivery (OR 1.33 95% CI 1.03-1.72, p = 0.031) and the time of the second stage of labor. Epidural analgesia seems to favor spontaneous delivery when it is properly carried on.
