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Objective To investigate the radiation dose to operators in the process of 241Am-Be neutron source logging, and discuss neutron source management and protective measures for operators in well logging. Methods Through on-site observation and measurement of 241Am-Be neutron source logging in a company, we obtained the surface γ dose rate and neutron dose rate of the neutron source, as well as the operating time and distance of various processes including source taking, transfer, and loading, calculated the radiation dose to operators in various processes, and analyzed the source and proportion of the personal effective dose to operators. Results The effective doses of neutron irradiation and γ irradiation were 94.17 μSv and 2.72 μSv, respectively, for the combined processes of source tank inspection, transfer, and detection; 36.66 μSv and 24.08 μSv, respectively, for source loading and unloading; and 130.83 μSv and 26.80 μSv, respectively, for the whole neutron source logging process. The total annual effective dose of neutron source logging was 15.78 mSv, as estimated by logging 100 times per year. Conclusion In the process of 241Am-Be neutron source logging in the company, the effective dose to operators mainly arises from neutron irradiation. Therefore, it is necessary to strengthen neutron source management and take effective protective measures against neutron radiation.
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Objective To determine the median effective dose (ED50) of oxycodone inhibiting responses to laryngeal mask airway (LMA) insertion when combined with propofol in the adult female patients.Methods Female patients,aged 18-60 yr,with body mass index of 18-24 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective gynecologic surgery,were included.ED50 of oxycodone was determined by up-and-down sequential technique.Anesthesia was induced by target-controlled infusion of propofol at target plasma concentration of 3.0 μg/ml.Oxycodone was injected at the initial dose of 0.11 mg/kg after the target effect-site and plasma concentrations were balanced.LMA was inserted at 5 min following injection.When the response to LMA insertion was positive,the concentration of oxycodone was increased/decreased in the next patient.The difference between the two successive doses was 0.02 mg/kg.LMA insertion response was defined as occurrence of swallowing,biting on the LMA and bucking and/or body movement during insertion.Probit analysis was used to calculate the ED50 and 95％ confidence interval of oxycodone inhibiting responses to LMA insertion when combined with propofol.Results The ED50 (95％ confidence interval) of oxycodone inhibiting responses to LMA insertion was 0.095 (0.080-0.108) mg/kg when combined with propofol.Conclusion The ED50 of oxycodone inhibiting responses to LMA insertion is 0.095 mg/kg when combined with propofol in the adult female patients.
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Objective To investigate the safety and effectiveness of different intravenous anesthesia methods for pediatric ERCP . Methods Data of 45 children undergoing ERCP at the Affiliated Hangzhou Hospital of Nanjing Medical University from August 2013 to July 2016, including intravenous anesthesia,the procedure of ERCP, adverse reactions and the waking time were retrospectively studied. Results A total of 45 patients in two groups under intravenous anesthesia successfully underwent ERCP . Seventeen patients ( 37. 8%) whose body weights were over 20 kg and the duration of surgery was predicted less than 30 minutes received deep sedation without airway intubation. Twenty?eight patients ( 62. 2%) with an initial weight of less than 20 kg and the duration of surgery was predicted more than 30 minutes received general anesthesia with airway intubation. In patients with deep sedation, the mean time of waking was 7. 2±6. 3 minutes, body movement reaction occurred in 1 case ( 5. 9%) and with transient decreasing of pulse blood oxygen ( beyond 95%) occurred in 2 cases ( 11. 8%) . In patients receiving endotracheal anesthesia with intubation, the mean waking time was 10. 5±8. 7 minutes without adverse reactions associated with anesthesia. Conclusion Both deep sedation and general anesthesia with airway intubation are safe for pediatric ERCP. However, general anesthesia with airway intubation is an ideal method ensuring the airway safety and oxygen supply for children less than 20 kg undergoing first?time ERCP or the duration of surgery lasting over 30 minutes.