Aerosol removal using flame-retardant atomized fixatives, as a major means of aerosol control, has achieved remarkable results in the field of nuclear facility decommissioning and decontamination. Traditional atomized fixatives for aerosol removal have deficiencies in high-temperature resistance and flame retardancy, rendering them inadequate for operational scenarios involving high temperatures and flammability encountered during nuclear decommissioning. This paper investigates the current development of flame-retardant atomized fixatives for aerosol removal both domestically and internationally and presents a preliminary exploration of this technology. The experiments showed that atomized fixatives modified with flame-retardant properties not only maintained excellent aerosol capture efficiency, but also exhibited significantly improved flame-retardant performance. This confirmed the technical feasibility of the proposed approach. Finally, suggestions and reflections are proposed for the development of this technology and its application in nuclear facility decommissioning.

Objective To investigate the imaging features of Langerhans cell histiocytosis(LCH)in the long bones of the limbs in children.Methods The clinical and imaging data of 23 children with long bones of the limbs were analyzed retrospectively.X-ray examinations were performed in 21 cases,CT scans in 16 cases,and MRI scans in 19 cases.Results The lesions were located in femur in 14 cases,tibia in 3 cases,fibula in 2 cases,humerus in 1 case,ulna in 2 cases,and both tibia and fibula in 1 case.Lesions were found in the diaphysis in 16 cases and the metaphysis in 7 cases(involving the epiphysis in 2 cases).Bone destruction appeared as oval,irregular,or eccentric shapes,with clear boundaries in 17 cases,blurred boundaries in 6 cases,and sclerosis in 6 cases.The average CT value was(48.27±8.20)HU,with"gear-like"changes in the axial view in 10 cases."Sleeve-like"periosteal reaction was observed in 14 cases,localized periosteal reaction in 5 cases,and no periosteal reaction in 4 cases.The lesions showed iso-or slightly hypointense signals on T1 WI,hyperintense signals on T2 WI,and hyperintense signals on diffusion weighted imaging(DWI),with an average apparent diffusion coefficient(ADC)value of(1.26±0.17)×10-3 mm2/s.Soft tissue masses were found in 7 cases.After enhancement,moderate to marked enhancement was observed in 9 cases,with lace-like enhancement in 6 cases.Among the 17 cases followed up,13 cases returned to normal or had only residual bone cortical thickening,3 cases showed a reduction in lesion size,and 1 case died.Conclusion The imaging features of LCH in the long bones in children have certain characteristics,but can still be easily confused with infections or malignant bone tumors.A comprehensive analysis combining clinical and imaging features is necessary to improve diagnostic accuracy.

This report described the multidisciplinary management of a preterm infant with congenital tracheal agenesis (TA). The infant, delivered via cesarean section at 32 +5 weeks' gestation, had Apgar scores of 6 and 8 at 1 and 5 minutes, respectively. Although skin color improved after 30 seconds of bag-mask ventilation, the infant exhibited no cry, weak spontaneous breathing, and failed multiple intubation attempts. The patient was transferred to Anhui Children's Hospital of Fudan University under continuous bag-mask positive-pressure ventilation at 3 hours after birth (September 10, 2024). Combined imaging and fiberoptic bronchoscopy confirmed TA (Floyd type Ⅱ/Faro type C) with multiple anomalies, including duodenal atresia, aortic coarctation, and butterfly vertebrae. Whole-genome sequencing revealed a suspected mosaic SCN2A c.5317G>A variant (wild-type parents) and an ERCC5 c.2974C>T heterozygous variant inherited from the mother (homozygous). Following esophageal intubation, invasive mechanical ventilation, and continuous gastrointestinal decompression, respiratory distress significantly improved with a stabilized condition. The infant died 30 hours after birth following treatment withdrawal.

Objective To investigate the imaging features of Langerhans cell histiocytosis(LCH)in the long bones of the limbs in children.Methods The clinical and imaging data of 23 children with long bones of the limbs were analyzed retrospectively.X-ray examinations were performed in 21 cases,CT scans in 16 cases,and MRI scans in 19 cases.Results The lesions were located in femur in 14 cases,tibia in 3 cases,fibula in 2 cases,humerus in 1 case,ulna in 2 cases,and both tibia and fibula in 1 case.Lesions were found in the diaphysis in 16 cases and the metaphysis in 7 cases(involving the epiphysis in 2 cases).Bone destruction appeared as oval,irregular,or eccentric shapes,with clear boundaries in 17 cases,blurred boundaries in 6 cases,and sclerosis in 6 cases.The average CT value was(48.27±8.20)HU,with"gear-like"changes in the axial view in 10 cases."Sleeve-like"periosteal reaction was observed in 14 cases,localized periosteal reaction in 5 cases,and no periosteal reaction in 4 cases.The lesions showed iso-or slightly hypointense signals on T1 WI,hyperintense signals on T2 WI,and hyperintense signals on diffusion weighted imaging(DWI),with an average apparent diffusion coefficient(ADC)value of(1.26±0.17)×10-3 mm2/s.Soft tissue masses were found in 7 cases.After enhancement,moderate to marked enhancement was observed in 9 cases,with lace-like enhancement in 6 cases.Among the 17 cases followed up,13 cases returned to normal or had only residual bone cortical thickening,3 cases showed a reduction in lesion size,and 1 case died.Conclusion The imaging features of LCH in the long bones in children have certain characteristics,but can still be easily confused with infections or malignant bone tumors.A comprehensive analysis combining clinical and imaging features is necessary to improve diagnostic accuracy.

This report described the multidisciplinary management of a preterm infant with congenital tracheal agenesis (TA). The infant, delivered via cesarean section at 32 +5 weeks' gestation, had Apgar scores of 6 and 8 at 1 and 5 minutes, respectively. Although skin color improved after 30 seconds of bag-mask ventilation, the infant exhibited no cry, weak spontaneous breathing, and failed multiple intubation attempts. The patient was transferred to Anhui Children's Hospital of Fudan University under continuous bag-mask positive-pressure ventilation at 3 hours after birth (September 10, 2024). Combined imaging and fiberoptic bronchoscopy confirmed TA (Floyd type Ⅱ/Faro type C) with multiple anomalies, including duodenal atresia, aortic coarctation, and butterfly vertebrae. Whole-genome sequencing revealed a suspected mosaic SCN2A c.5317G>A variant (wild-type parents) and an ERCC5 c.2974C>T heterozygous variant inherited from the mother (homozygous). Following esophageal intubation, invasive mechanical ventilation, and continuous gastrointestinal decompression, respiratory distress significantly improved with a stabilized condition. The infant died 30 hours after birth following treatment withdrawal.

Objective To calculate the absorbed dose of ⁹⁰Y TheraSphere in the pancreas and the surrounding sensitive organs after the administration in the treatment of pancreatic cancer through the establishment of an individual voxel model, and to provide technical support for the clinical application of ⁹⁰Y TheraSphere in the treatment of pancreatic cancer. Methods An individualized voxel model was constructed in Geant4 software based on the CT images of the patient. 12 monoenergetic electron specific absorption fractions (SAFs) in the range of 0.01 to 1 MeV were calculated and validated against the ICRP data. The model and method were used to calculate the absorbed doses in the target organs under uniform and nonuniform distribution of ⁹⁰Y microspheres in the pancreas. Results The relative errors between the SAF values calculated based on the individualized voxel model and the ICRP data after mass calibration were less than 3.89%. When ⁹⁰Y was uniformly distributed in the pancreas, the absorbed dose in the pancreas was 4.69 × 10⁻⁷ Gy/Bq; the absorbed doses in the liver, kidneys, and spleen were 6.15 × 10⁻¹², 6 × 10⁻¹², and 1.65 × 10⁻¹¹ Gy/Bq, respectively. When ⁹⁰Y was distributed within the tumor, the absorbed dose in the tumor was 6.69 × 10⁻⁶ Gy/Bq and the absorbed dose in normal pancreas was 5.72 × 10⁻⁸ Gy/Bq. The fitted relationship between tumor volume V and administered activity A at the prescribed dose of 120 Gy was quadratic, with relatively low activity required for concentrated administration in the center of the tumor. Conclusion The Monte Carlo dose calculation method based on individual voxel model accurately predicted the absorbed doses in the surrounding sensitive organs (liver, kidneys, and spleen) when ⁹⁰Y TheraSphere was used to treat pancreatic cancer. These results and the analysis of the factors affecting the drug delivery activity will provide data support for the clinical research of ⁹⁰Y TheraSphere in pancreatic cancer.

Objective To address the radioactive contamination of wounds caused by transuranic nuclides, wound radiation imaging based on coded aperture imaging technology was investigated. Methods By simulating multiple source terms using Monte Carlo method, the differences in imaging performance between two image reconstruction algorithms under near-field conditions were compared. The effects of detector pixels and detection plane pixels on image resolution were investigated. Results The imaging system was simulated based on the designed dimensions. The simulated imaging field of view was 89.4 mm × 89.4 mm and the simulated angular resolution was 1.98°. Based on the comparison of the average width at half height of the reconstructed point sources under different conditions, it was found that increasing the number of pixels in the detector and detection plane optimized the angular resolution but significantly prolonged the Monte Carlo simulation time. Conclusion According to the simulation results, the parameters of the imaging system can be used to effectively image radioactive contamination. Our results provide methodological support for the measurement of wound contamination caused by transuranic nuclides, and lay the foundation for the development of wound contamination imaging detection systems in the future.

Objective To investigate the natural penetrating radiation levels along the Qinghai-Tibet Railway, and to preliminarily evaluate the doses received by the railway employees and passengers. Methods Natural penetrating radiation was measured at 15 typical locations with different altitudes along the railway and in the carriages of a train from Lhasa to Xining using high-pressure ionization chamber RSS131, sodium iodide radiation dose rate meter MARS1561, and neutron ambient dose equivalent rate meter LB6411. Results The levels of terrestrial gamma radiation, cosmic ray ionization components, and neutron radiation were 21.5-246.6 nGy/h, 79.8-225.5 nGy/h, and 24.5-101 nSv/h, respectively. The effective dose of natural penetrating radiation received by passengers and crew on a train from Lhasa to Xining was 4.82 μSv. Conclusion Comparison with the empirical formula and verification of method reliability confirm the accuracy of the measurement. Our results provide a primary understanding of the radiation levels along the Qinghai-Tibet Railway and the radiation doses received by passengers, which can be used as a basis for the regulatory authorities.

Objective Nowadays, radioactive xenon isotopes, including ^131mXe, ^133mXe, ¹³³Xe, and ¹³⁵Xe, are primarily released into the atmosphere through various reactor operation and major accidents of reactors. To improve the online monitoring capability of xenon in nuclear facilities and their gaseous effluents, a highly sensitive online xenon monitoring system was developed to monitor, warn, and alarm the activity concentration of radioactive xenon. Methods The online monitoring system for radioactive xenon gas in nuclear facilities was established using xenon membrane separation and concentration, xenon high-efficiency selective adsorption, and low-background gamma-ray spectrometry analysis methods. Results Under the operation mode of one-hour sampling and one-hour measuring, the minimum detectable activity concentration of the radioactive xenon online monitoring system for ¹³³Xe was approximately (1.43 ± 0.03) Bq/m³. Conclusion This system can be effectively used for online monitoring of xenon activity concentration in nuclear facilities such as nuclear power plants and isotope production reactors, as well as in gaseous effluents. It helps improve the safety level of personnel, the environment, and nuclear facilities.

Objective To establishment a process of monitoring waste resin clearance in nuclear power plants, and to meet clearance requirements and simplify the monitoring work. Methods In accordance with the requirements specified in current laws, regulations, and standards in China, as well as the practice of slightly polluted waste resins generated during the operation of nuclear power plants, in-depth discussion was conducted on sampling methods, sample uniformity and representativeness tests, radiation monitoring contents and methods, and simplified monitoring processes, in order to accurately monitor the radionuclide activity of waste resins to be cleared. Results A process was established to monitor waste resin clearance in nuclear power plants. A total of 55 barrels of waste resins were cleared and the radiation levels met the requirements. Conclusion An effective clearance process can facilitate the sampling of representative resins, improve the accuracy of monitoring data, differentiate radioactive waste from cleared waste, and simplify the monitoring process. Our results provide a basis and reference for future waste resin clearance.