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Objective To investigate the effect of gaseous effluent from the six generator sets on the radiation level of the surrounding terrestrial environment in Daya Bay Nuclear Power Base after the operation of Ling’ao Nuclear Power plant. Methods The radiation level in the peripheral environment of the Base was monitored using the thermoluminescence dosimeter （TLD）. Twenty-five monitoring sites were set around the Base to investigate the variation of radiation level over a long period of time by collecting the TLDs every three months. Results From 2011 to 2020, the annual γ dose rate of the 25 sites ranged from 76.7 to 207.1 nGy/h, with an average value of (123.3 ± 5.7) nGy/h and a relative deviation of 2%-12%. The TLD monitoring and instantaneous measuring results of γ dose rate were consistent with the survey of the State Environmental Protection Administration in the 20th century and the baseline level prior to the operation of the nuclear power plant. Conclusion There are great differences in natural environmental radiation level across the TLD monitoring sites. The overall environmental γ radiation level within 50 km of the nuclear power base remains unchanged. The emission of gaseous effluent from the operation of the nuclear power plant does not have a cumulative impact on the radiation level of surrounding environment.
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Objective:To evaluate the radiation dose to the injured persons in a radiological accident, provide the guidance on the diagnosis and treatment of radiation injury, and provide the basis for determination of the level of radiological accident.Method:Firstly, the air-absorbed dose rates at 206 locations surrounding a X-ray device were measured by using LiF (Mg, Cu, P) thermoluminescence detectors and self-made radiation field measuring frames. Secondly, the spatial distribution of radiation level was obtained by fitting the inverse square law between absorbed dose rate and distance, which is used as the basis of dose estimation. Finally, based on the actual working conditions of injured operators, a parameter calculation method was proposed for estimating hand skin absorbed dose.Results:The air-absorbed dose rate surrounding X-ray beam outlet was higher than 1.0 mGy/h. The maximum air-absorbed dose rate value in the space of within 200 cm outside X-ray beam outlet was 262 μGy/h and the minimum value was 2.1 μGy/h, 2 orders of magnitude higher than environmental background level. During normal operation, the total absorbed doses to the hand skin of two injured female operators were 36.9 and 16.9 Gy, respectively. During extreme operation, the hand skin-received total absorbed doses to the two operators were 85.2 and 38.9 Gy, respectively. Under the occupational health standard GBZ 106-2020, the two persons had acute radiation skin injury of grade Ⅲ or Ⅳ on their hands.Conclusions:The results of hand skin exposure doses provide effective support for diagnosis and treatment of radiation injuries and for the determination of radiological accident level. The method used in radiation field reconstruction and dose estimation mentioned in this study can provide reference for the treatment in the similar radiological accident.
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<p><b>OBJECTIVE</b>To evaluate the diagnostic value of salivary and plasma miR-21 in patients with esophageal cancer (EC).</p><p><b>METHODS</b>Total RNA was extracted from saliva and plasma samples from 50 stage I and 50 stage II patients with EC and 50 healthy controls for measurement of miR-21 levels using qPCR. The diagnostic values of salivary and plasma miR-21 levels were assessed for stage I, stage II, and stage I+II EC.</p><p><b>RESULTS</b>Salivary and plasma miR-21 were significantly higher in the EC patients than in the control group. The diagnostic sensitivities of plasma miR-21 for stage I, stage II, and stage I+II EC were 96%, 64% and 97%, with specificities of 44%, 84%, and 56%, respectively; the sensitivities of salivary miR-21 were 90%, 88%, and 89%, respectively, with the same specificities of 64%. Regardless of EC staging, the expression of plasma miR-21 showed a significant positive correlation with that of salivary miR-21, and their diagnostic values were comparable.</p><p><b>CONCLUSION</b>Both salivary and plasmatic miR-21 can be sensitive biomarkers for EC, and salivary miR-21 detection has the potential to replace plasma detection for EC diagnosis.</p>