Objective: To  investigate  the  effect  of  X-ray  on  the  polarization  of  mouse  microglia  BV-2  cells. Methods: BV-2 cells at the logarithmic growth stage were randomly divided into the Sham irradiation group and 10 Gy irradiation group. The latter group was given a single X-ray irradiation at a dose of 1.28 Gy/min for 7 min 49 s. The activation rate of BV-2 cells was observed and analyzed under a microscope at 1, 3, 6, 24 h and 48 h after irradiation.The changes of cell morphology were observed by HE staining and immunofluorescence staining; The levels of M1-type activation markers (TNF-α and IL-1β) and M2-type activation marker TGF-β1 in the supernatant of BV-2 cells were detected by ELISA. The levels of polarization-related proteins of M1-type (CD86 and iNOS) and M2-type (CD206) in BV-2 cells were detected by Western blotting. Results　: Morphological results showed that BV-2 cells became larger, and their protrude became coarse and shorter, showing "amoeba" like changes after 10 Gy X-ray irradiation. Compared with the Sham group, the activation rate of BV-2 cells was significantly increased at 3 h, and reached the peak at 6 h, and began to recover at 48 h after irradiation. ELISA results showed an obvious increase in the level of TNF-α and TGF-β1 48 h after irradiation.The level of IL-1β showed a transient decrease at 3～6 h, increased at 24 h, and reached the peak 48 h after irradiation. Western blotting results showed that CD86 protein level did not change significantly at each time points after irradiation, and iNOS protein level in- creased significantly at 1, 6, 24 h and 48 h after irradiation. A fluctuating change in CD206 protein level was found after irradiation. Conclusion　 10 Gy X-ray irradiation can induce the activation of BV-2 cells in vitro, and the polarization type changes with the time after irradiation.

Objective To understand the present state of radiological diagnosis and treatment resources allocation and to provide data support for the health administrative department to further optimize the allocation of resources in Linyi. Methods All hospitals which conducted radiological diagnosis and treatment in the city were surveyed. The data were analyzed by using SPSS software. Results There were 305 radiological diagnosis and treatment institutions, with 943 sets of radiological diagnosis and treatment equipment in Linyi. There were 0.89 sets of diagnostic and therapeutic equipment per 10000 people, and the average number of diagnostic and therapeutic equipment per institution in urban areas is 1.48 times that in county areas. There were 2208 radiological diagnosis and treatment staff in the city, and each hospital had 7.24 radiation staff, among which the number ofin tertiary, secondary, primary and unrated hospitals was 89.63, 17.64, 3.37 and 2.77, respectively. Conclusion The allocation of Diagnostic Radiology equipment is out of balance in Linyi, and the large-scale Diagnostic Radiology equipment is less and distributed centrally. The number of diagnostic and therapeutic radiographers per 10000 people is insufficient and unevenly distributed. Radiological diagnosis and treatment resources should be allocated scientifically to promote balanced development among regions and optimize the allocation of resources.

Objective To further strengthen the management of radiological health technical service institutions, standardize their technical service behaviors, and explore the supervision countermeasures for radiological health and technical service institutions. Methods The radiological health technical service institutions status questionnaires s were designed to survey the basic situation, professionals and technical personnel, the equipment configuration, testing items and workload of service institutions. Results By the end of 2019, there were 23 radiological health technical service institutions in Hebei province, including 8 disease control and occupational prevention institutions (accounting for 34.8%) and 15 third-party institutions (accounting for 65.2%); The distribution of regional agencies were unbalanced; There were 223 professional and technical personnel, of which 29.6% were senior technical professionals, 29.6% were intermediate technical professionals and 40.8% were other professionals.58.8% had a bachelor's degree or above, and 41.2% had a college degree or below; The majors of professionals were relatively scattered, with only 6.44% of radiological health, 5.15% of physics-related majors, and 51.07% of medical-related majors. Other majors involve chemical pharmacy, environmental engineering, public relations planning, food, English, accounting and other majors.The professional technical responsible person had no part-time job;. The institution were totally equipped with 308 sets of radiation protection detectors and 172 sets of phantoms, basically in line with the configuration requirements; All quality control system documents such as quality management manuals, procedural documents, operating procedures, and work instructions have been established; All test items applied by laboratory measurement certification have passed;Conclusion The CDC institutions were gradually shrinking, the private institutions were gradually increasing and the nature of the institutions was gradually diversified.The allocation of regional resources was unbalanced.It is suggestedto strengthen the training on the theoretical basis and professional skills of professionals in testing and evaluation. Increasing on-site practical training is a more important and effective way.It is recommended to strengthen the training of basic-level health administrative departments and supervisory agencies and improvethe sense of responsibility of supervisors.

objective This paper analyzes the physical examination results of blood routine, chromosome deformity rate, micronucleus rate and thyroid function test of some radiation workers in Chongqing from 2018 to 2019, understands the occupational problems of radiation workers, and provide scientific basis for putting forward reasonable suggestions method:Methods 2656 cases in 2018 and 2922 cases in 2019 were selected through the information platform of physical examination system. A total of 5578 physical examination results in two years were statistically analyzed and analyzed. Results The abnormal rate of blood routine, the detection rate and abnormal rate of chromosome distortion and micronucleus, and the abnormal rate of thyroid gland function (T3, T4, TSH) between the control group and the radiation group are significant differences (P < 0.05). There were significant differences in the abnormal rate of blood routine, thyroid function (T3, T4, TSH), chromosome teratosis rate, micronucleus detection rate and abnormal rate between radiation diagnosis and treatment and industrial flaw detection, but there was no significant difference in the abnormal rate of chromosome (P > 0.05). There was significant difference between < 10 year group and 10 ～20 year group, and there was significant difference in platelet, white blood cell and hemoglobin between 10 ～20 year group and 20 year group (P < 0.05). There was no statistical significance in erythrocyte difference (P > 0.05). There was significant difference in the abnormal rate of thyroid function among the three working age segments (P < 0.05). The detection rate of chromosome distortion was significantly different between < 10 years group and 10 ～20 year group (P < 0.05), but there was no significant difference between the other two groups (P > 0.05). There was significant difference in the abnormal rate between the two groups (P < 0.05). There was no significant difference in pairwise comparison of micronucleus detection rate among groups (P > 0.05), but there was significant difference in abnormal rate among groups (P < 0.05). Conclusion The long-term low dose ionizing radiation environment will damage the hematopoietic and endocrine system of radiation sensitive human body.

Objective To analysis contraindication detection of radiological workers and explore thevariation trend. Methods Occupational health examination data of radiological workers were selected from 2014 to 2018. Contraindications were identified according to the criteria, and the detection rates and trends were described in each statistical dimension. Results A total of 17197 cases were selected. Among them 74 patients were found contraindication and the detection rate is 0.43%. The major abnormalities were in thyroid gland and crystalline lens; The detection rate of female is higher than that of male (χ² = 25.24，P < 0.01); High age andhigh working age groups showed a higherrate of contraindication detection; The abnormal rate of contraindication increased with the age; The risk of > 30 working years group is 2.541 times that of 1 ～5 working years group (95%CI: 1.32 ～4.88). The abnormal rate of thyroid grand was increased year by year, and the trend test showed statistical significance (χ² = 3.87，P < 0.05). Conclusion Low dose ionizing radiation has a great effect on thyroid gland and crystalline lens of radiation workers, whichhigh age and high working years group should be pay attention to. The contents of occupational health monitoring should be further regulated to safeguard the health of radiation workers so that we can discover the possible health effects and take intervention earlier.

Objective To investigate the effects of particle size, wind speed and dumping velocity on aerosol concentration distribution during powder dumping in a reprocessing plant. Methods CeO₂ powder was selected as the substitute material of PuO₂. FLUENT software was used to calculate the pouring process of CeO₂ powder under different operation conditions. Then the aerosol concentration distribution under different dumping speeds was measured by particle size spectrometer to verify the accuracy of simulation results. Results The particles with small particle size are more likely to be separated from the mainstream area by the drag force of the surrounding gas, and the radius of the diffusion range also increases with the decrease of the particle size. 2) When the ventilation speed is less than 1 m/s, the dust lifting can be reduced and the concentration of dust particles in the chamber can be reduced to a certain extent. 3) In the process of powder dumping, the spoon is rotated anticlockwise at a speed of 100° in 2～3 s, and less dust aerosol is produced on the right side of the tray. Conclusion When operating the powder particles with smaller particle size, more attention should be paid to the monitoring of aerosol at different positions; the change of air inlet velocity makes the flow field in glove box more complex, and the volume fraction of dust particles is related to the size and location of vortex formed by airflow. The greater the wind speed, the greater the impact on the powder dumping process. The experimental results are basically consistent with the simulation results, and the results show that the lower the dumping speed, the smaller the aerosol concentration near the tray.

Objective Based on the lanthanum bromide scintillator detector, the calculation method of G(E) function was developed to measure the air absorbed dose rate. Methods Firstly, the gamma energy spectrumof the lanthanum bromide detector were simulated and the response functions with different energies were determined with Monte Carlo simulation method. Then, the G(E) function was calculated by the least square method. Finally, the air absorbed dose rate measured by the lanthanum bromide detector using G(E) function conversion method was compared with the theoretical calculation value based on the point source experiments. Results The experimental verification results showed that the relative deviation between thecalculated value with G(E) function and the theoretical calculation value wasmostly controlled within ± 6%, which verified the accuracy of G(E) function. Conclusion The results showed that the method of G(E) function could be applied to calculate the gamma radiation dose rate based on the in-situ the gamma spectrum with LaBr₃ detector.

Objective In order to test and improve the monitoring technical level and ability of radiation environmental monitoring network in Zhejiang Province, ensure the accuracy and reliability of monitoring data and information, and obtain the cosmic ray response values of instruments and equipment in this year. Methods In September 2018，an intercomparison meeting of environmental gamma radiation air absorbed dose rate within the radiation environmental monitoring network of Zhejiang province was held in Ningbo，which was organized by Zhejiang Province Radiation Environmental Monitoring Center.A total of 33 sets of instruments from 15 member units participated in the intercomparison measurements at 5 environmental measuring points, and the comparison results were evaluated by the Z score values. Results It was found that the |Z| of all measurement results were less than or equal to 2, and the evaluation results were satisfactory and acceptable. Conclusion The measured data of scintillation counters have relatively wider dispersion，and the high pressure ionization chambers have bigger response valuetocosmic ray. The measurement results of the two kinds of instruments keep a good linearity except for the measurement points of cosmic ray response.

Objective To prove the feasibility of a Fogging Process in fixing high-concentration radioactive aerosol ¹³¹I contamination. Methods High-concentration radioactive aerosol ¹³¹I contamination in an ¹³¹I-operating glovebox for radiopharmaceutical production was disposed by using fogging and fixing process. The aerosol ¹³¹I concentrations were detected and the results were analyzed. Results After a 120 minutes fixing, the ¹³¹I contamination in this glovebox reduced from(289 ± 9) DAC and (304 ± 6) DAC to (21.7 ± 2.0) DAC and (26.2 ± 1.8) DAC. After a 180 minutes fixing, the ¹³¹I contamination in this glovebox reduced from (259 ± 10) DAC to (1.80 ± 0.18) DAC. These results showed that no aerosol ¹³¹I contamination was raised again after 24-hours finishing this task. Conclusion Aerosol ¹³¹I concentration in a limited space could be controlled by using a fogging and fixing process, which could reduce the risk of internal exposure of staff. This process could be used by radiopharmaceutical production as an emergency management for dispose high-concentration radioactive aerosol ¹³¹I contamination.

Objective To design and build a set of experimental equipment for neutron radiation irradiation by using the ²⁴¹Am-Be neutron source. Methods In the preliminary work, the spatial distribution data of the neutron energy spectrum and the gamma energy spectrum inside and outside the device were simulated by Monte Carlo method, and the changes of radiation fluence rate with spatial distribution was studied. The model of the ²⁴¹Am-Be neutron device was established, and the neutron transport process in the irradiation field was studied using the method of shadow cone, inverse square law and other data analysis methods. Results Based on the simulation results, the normalized effective does of fast neutron fluence at the measurement point is about 72.9 pSv/n, and the one of photon fluence is about 3.04 pSv/γ. The ratio of effective dose of photon fluence to neuteon is about 4.17%. Conclusion Using Monte Carlo method, a standard model of ²⁴¹Am-Be neutron source was constructed, the shadow cone design was optimized, and the feasibility of using the shadow cone conversion method to establish a standard neutron source radiation device was discussed.