Objective: The Great East Japan Earthquake (magnitude, 9.0) followed by a large-scale tsunami caused a severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant (Tokyo Electric Company). This study aimed to...Objective: The Great East Japan Earthquake (magnitude, 9.0) followed by a large-scale tsunami caused a severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant (Tokyo Electric Company). This study aimed to evaluate the obstetric outcomes in women in Fukushima prefecture during and after the Great East Japan Earthquake and Fukushima nuclear power plant accident. Methods: We collected information for 12,300 pregnant women who conceived during the 9 months before and after the disaster in Fukushima prefecture. The data of the subjects were analyzed according to the conception date for each pregnancy. Results: Among the women who conceived within 9 months before the disaster, adverse obstetric outcomes were not observed. In contrast, in the case of women who conceived within 6 months after the disaster, an increase in the incidence of preterm birth (less than 37 weeks) and low birth weight (less than 1500 g and less than 2500 g) was observed. Moreover, these women showed an increased incidence of medical complications, such as respiratory diseases and mental disorders. Conclusion: The results of the present study show that the occurrence of adverse obstetric outcomes was higher in the women who conceived within 6 months after the disaster than in those who were pregnant at the time of the disaster. The results may be related to emotional stress such as anxiety about the disaster and emphasize the need for continued investigations and careful management of pregnant woman in disaster areas in the future.展开更多
In this study,large-area(6-cm diameter)Teflon polytetrafluoroethylene(PTFE)discs of different thicknesses(0.2-,0.5-and 1-mm)were negatively and positively charged by using the“modified single point-to-plane corona po...In this study,large-area(6-cm diameter)Teflon polytetrafluoroethylene(PTFE)discs of different thicknesses(0.2-,0.5-and 1-mm)were negatively and positively charged by using the“modified single point-to-plane corona poling rotating system”.The effects of some crucial parameters of the PTFE disc as well as the modified corona poling rotating system on the PTFE surface potential uniformity such as.(a)PTFE disc thickness,(b)PTFE disc polarity and(c)needle-to-PTFE disc distance were successfully reported.Accordingly,closer needle-to-PTFE disc distance,positive charging mode and thinner PTFE disc provided a better PTFE surface potential uniformity.However,the effects of PTFE charge polarity and needle distance on the electrostatic charge potential uniformity were much more remarkable in comparison with the effects of PTFE thickness.Additionally,the surface potential distribution profiles of charged PTFE discs were totally flat and independent of the PTFE thickness at 5-and 13-mm needle distances for the negative and positive charging modes,respectively.At the optimized charging conditions,large-area PTFE electret disc(0.5-mm-thick)with positive uniform surface charge potential especially at the edges up to1.8 kV with stability up to 77 days studied was produced by applying a new multiple heat treatment protocol to the PTFE disc for radon dosimetry.As also observed in this study,the sensitivity of PTFE electret dosimeters to a defined radon gas concentration increases as the PTFE thickness increases.Meanwhile,0.5-mm-thick PTFE electret disc produced was selected to be used as a high quality electret dosimeter with acceptable and superior parameters for different applications in particular medium-term radiation dosimetry in both low and high dose rate ionizing radiation fields.展开更多
文摘Objective: The Great East Japan Earthquake (magnitude, 9.0) followed by a large-scale tsunami caused a severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant (Tokyo Electric Company). This study aimed to evaluate the obstetric outcomes in women in Fukushima prefecture during and after the Great East Japan Earthquake and Fukushima nuclear power plant accident. Methods: We collected information for 12,300 pregnant women who conceived during the 9 months before and after the disaster in Fukushima prefecture. The data of the subjects were analyzed according to the conception date for each pregnancy. Results: Among the women who conceived within 9 months before the disaster, adverse obstetric outcomes were not observed. In contrast, in the case of women who conceived within 6 months after the disaster, an increase in the incidence of preterm birth (less than 37 weeks) and low birth weight (less than 1500 g and less than 2500 g) was observed. Moreover, these women showed an increased incidence of medical complications, such as respiratory diseases and mental disorders. Conclusion: The results of the present study show that the occurrence of adverse obstetric outcomes was higher in the women who conceived within 6 months after the disaster than in those who were pregnant at the time of the disaster. The results may be related to emotional stress such as anxiety about the disaster and emphasize the need for continued investigations and careful management of pregnant woman in disaster areas in the future.
文摘In this study,large-area(6-cm diameter)Teflon polytetrafluoroethylene(PTFE)discs of different thicknesses(0.2-,0.5-and 1-mm)were negatively and positively charged by using the“modified single point-to-plane corona poling rotating system”.The effects of some crucial parameters of the PTFE disc as well as the modified corona poling rotating system on the PTFE surface potential uniformity such as.(a)PTFE disc thickness,(b)PTFE disc polarity and(c)needle-to-PTFE disc distance were successfully reported.Accordingly,closer needle-to-PTFE disc distance,positive charging mode and thinner PTFE disc provided a better PTFE surface potential uniformity.However,the effects of PTFE charge polarity and needle distance on the electrostatic charge potential uniformity were much more remarkable in comparison with the effects of PTFE thickness.Additionally,the surface potential distribution profiles of charged PTFE discs were totally flat and independent of the PTFE thickness at 5-and 13-mm needle distances for the negative and positive charging modes,respectively.At the optimized charging conditions,large-area PTFE electret disc(0.5-mm-thick)with positive uniform surface charge potential especially at the edges up to1.8 kV with stability up to 77 days studied was produced by applying a new multiple heat treatment protocol to the PTFE disc for radon dosimetry.As also observed in this study,the sensitivity of PTFE electret dosimeters to a defined radon gas concentration increases as the PTFE thickness increases.Meanwhile,0.5-mm-thick PTFE electret disc produced was selected to be used as a high quality electret dosimeter with acceptable and superior parameters for different applications in particular medium-term radiation dosimetry in both low and high dose rate ionizing radiation fields.
