Background ¹³⁷Cs in atmospheric aerosol is the product of past nuclear weapon tests and nuclear accidents. When ¹³⁷Cs is released into the atmosphere, it will deposit in dry land and marine environment, causing pollution of soil surface, water, agricultural products, and animal byproducts, and affecting public health. Objective To identify the variation pattern of ¹³⁷Cs activity concentration in aerosol and its correlation with dust concentration in Beijing area from 2017 to 2020. Methods A total of 958 aerosol samples were collected from November 1, 2017 to June 30, 2020 in Beijing with a high volume air sampler at a sampling flow rate about 600 m³·h⁻¹ and a collection time for each sample about 24 h. The activity concentration of ¹³⁷Cs in the aerosol samples was determined with a low-background high-purity germanium γ spectrometer. The dust concentration was calculated using the difference in the mass of the aerosol filter before and after sampling. The detection rate of ¹³⁷Cs and dust concentration in different seasons were compared. Spearman rank correlation test was used to analyze the correlation between ¹³⁷Cs activity concentration and dust concentration. Results From 2017 to 2020, the ¹³⁷Cs activity concentrations of 33 from 958 aerosol samples in Beijing were above the minimum detectable activityconcentration, the overall detection rate of ¹³⁷Cs was 3.4%, and the activity concentration ranged from 1.86 to 45.53 μBq·m⁻³, with a median value of 4.85 μBq·m⁻³. The detection rate of ¹³⁷Cs was highest in spring, followed by autumn, and lowest in winter and summer (8.4%, 3.0%, 1.1%, and 0.5%, respectively). The dust concentration ranged from 0.03 to 1.55 mg·m⁻³, with an average value of 0.18 mg·m⁻³. There was a statistically significant difference in the dust concentrations in spring, summer, autumn, and winter (F=45.51, P<0.05), and the highest value was 0.24 mg·m⁻³ in spring (P<0.05). The ¹³⁷Cs activity concentration was positively correlated with the dust concentration (P<0.05). Conclusion The ¹³⁷Cs activity concentration in aerosol in Beijing from 2017 to 2020 fluctuates within the range of background level, and its activity concentration is highest in spring, followed autumn, and lowest in summer and winter.

Objective To explore the role of zinc finger protein 36 (ZFP36) in regulating osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and preosteoblasts. Methods ZFP36 expression was observed in primary mouse BMSCs and mouse preosteoblasts (MC3T3-E1 cells) during induced osteogenic differentiation. Zfp36-deficient cell models were constructed in the two cells using RNA interference technique and the changes in differentiation capacities of the transfected cells into osteoblasts were observed. Transcriptome sequencing was used to investigate the potential mechanisms of ZFP36 for regulating osteoblast differentiation of the two cells. U0126, a ERK/MAPK signal suppressor, was used to verify the regulatory mechanism of Zfp36 in osteogenic differentiation of Zfp36-deficient cells. Results During the 14-day induction of osteogenic differentiation, both mouse BMSCs and MC3T3-E1 cells exhibited increased expression of ZFP36, and its mRNA expression reached the peak level on Day 7 (P<0.0001). The Zfp36-deficient cell models showed reduced intensity of alkaline phosphatase (ALP) staining and alizarin red staining with significantly lowered expressions of the osteogenic marker genes including Alpl, Sp7, Bglap and Ibsp (P<0.01). Transcriptome sequencing verified the reduction of bone mineralization-related gene expressions in Zfp36-deficient cells and indicated the involvement of ERK signaling in the potential regulatory mechanism of Zfp36. Immunoblotting showed that pERK protein expression increased significantly in Zfp36-deficient cells compared with the control cells. In Zfp36-deficient MC3T3-E1 cells, inhibition of activated ERK/MAPK signaling with U0126 resulted in obviously enhanced ALP staining and significantly increased expressions of osteoblast differentiation markers Runx2 and Bglap (P<0.05). Conclusions ZFP36 is involved in the regulation of osteoblast differentiation of mouse BMSCs and preosteoblasts, and ZFP36 deficiency causes inhibition of osteoblast differentiation of the cells by activating the ERK/MAPK signaling pathway.

Objective:To investigate the application value of modified multivisceral trans-plantation (MMT) in chronic intestinal pseudo-obstruction (CIPO) secondary to autoimmune enteril leiomyositis (AEL).Methods:The retrospective and descriptive study was conducted. The clinico-pathological data of a recipient who was admitted to Beijing Tsinghua Changgung Hospital Affiliated to Tsinghua University on February 2022 and underwent MTT for CIPO secondary to AEL were collected. The recipient was a male, aged 29 years old. Results of preoperative histopathological examination showed that there were muscle plexus and ganglion cells in the rectum, sigmoid colon, ascending colon, intrinsic muscle layer of ileum, and a small amount of submucosal layer. There was also a small amount of chronic inflammatory cell infiltration in the muscle, indicating a high possi-bility of diagnosis of neurogenic CIPO.Results:(1) Surgical situations. The operation time was 14 hours and 30 minutes, and the cold ischemia time was 9 hours and 30 minutes. The intra-operative blood product dosage included 14 U of red blood cells, 1 400 mL of fresh frozen plasma, and two therapeutic doses of platelets. (2) Postoperative histopathological examination. Results of postoperative histopathological examination showed chronic inflammation and local erosion of the small intestine and duodenal mucosa, with scattered disappearance of the focal mucosal muscle layer; There is a large infiltration of CD3 + and CD8 + lymphocytes in the lamina propria, especially in the muscularis propria. In severe lesions, there is infiltration of ribbon lymphocytes in the subserosal and muscular layers; Muscle fiber degeneration, reduction, and fibrosis. Deposition of pigment granules in the cytoplasm of smooth muscle cells; No abnormalities were found in the intermuscular, submu-cosal ganglia, and Cajal cells; Fibrosis of the serosal layer with local cellulose exudation; Chronic inflammation of the colonic mucosa, scattered and focal lymphocyte infiltration in the local muscle layer, and myositis related changes. Pathological diagnosis was secondary CIPO induced by AEL. (3) Postoperative immune rejection, recurrence and treatment. Results of colonoscopy and histopatholo-gical examination at postoperative 8 days showed acute cellular rejection. The cell count of reci-pient′s B lymphocytes, CD3 + lymphocytes, CD4 + lymphocytes, and CD8 + lymphocytes were 27.00×10 3, 373.00×10 3, 179.00×10 3 and 142.00×10 3 cell/mL, respectively. Anti-immune rejection treatment was performed using tacrolimus, rabbit anti-human thymocyte immunoglobulin, methylprednisolone mycophenolate mofetil, and monoclonal antibodies against basil. The cell count of recipient′s B lymphocytes, CD3 + lymphocytes, CD4 + lymphocytes, and CD8 + lymphocytes at postoperative 57 days were 0.72×10 3, 239.59×10 3, 89.28×10 3 and 91.53×10 3 cell/mL, respectively. Results of colonoscopy and histopathological examination at postoperative 79 days showed the recurrence of AEL. The cell count of recipient′s B lymphocytes, CD3 + lymphocytes, CD4 + lymphocytes, and CD8 + lymphocytes were 0.32×10 3, 264.92×10 3, 46.95×10 3 and 169.54×10 3 cell/mL, respectively. The tacrolimus and methylprednisolone were used for treatment. Results of colonoscopy and histopathological examina-tion at postoperative 89 days showed AEL recurrence without remission. The cell count of recipient′s B lymphocytes, CD3 + lymphocytes, CD4 + lympho-cytes, and CD8 + lymphocytes were 0.28×10 3, 187.00×10 3, 55.52×10 3 and 92.45×10 3 cell/mL, respec-tively. The tacrolimus and methylprednisolone were used for treatment. Results of colonoscopy and histopathological examination at postoperative 92 days showed the intestinal mucosa had returned to a normal state. (4) Postoperative oral feeding time and time to get rid of parenteral nutrition. The recipient began oral feeding at postoperative 28 days and eliminated parenteral nutrition at postoperative 35 days. (5) Follow-up. The recipient was discharged 114 days after surgery and as of the follow-up deadline, the graft function was good. The recipient maintained a low-fat, high sugar, and high protein diet, completely consumed orally, with a body mass index of 22 kg/m 2, and has returned to normal work. Conclusion:MMT can be used for the treatment of CIPO secondary to AEL.

Objective To explore the role of zinc finger protein 36 (ZFP36) in regulating osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and preosteoblasts. Methods ZFP36 expression was observed in primary mouse BMSCs and mouse preosteoblasts (MC3T3-E1 cells) during induced osteogenic differentiation. Zfp36-deficient cell models were constructed in the two cells using RNA interference technique and the changes in differentiation capacities of the transfected cells into osteoblasts were observed. Transcriptome sequencing was used to investigate the potential mechanisms of ZFP36 for regulating osteoblast differentiation of the two cells. U0126, a ERK/MAPK signal suppressor, was used to verify the regulatory mechanism of Zfp36 in osteogenic differentiation of Zfp36-deficient cells. Results During the 14-day induction of osteogenic differentiation, both mouse BMSCs and MC3T3-E1 cells exhibited increased expression of ZFP36, and its mRNA expression reached the peak level on Day 7 (P<0.0001). The Zfp36-deficient cell models showed reduced intensity of alkaline phosphatase (ALP) staining and alizarin red staining with significantly lowered expressions of the osteogenic marker genes including Alpl, Sp7, Bglap and Ibsp (P<0.01). Transcriptome sequencing verified the reduction of bone mineralization-related gene expressions in Zfp36-deficient cells and indicated the involvement of ERK signaling in the potential regulatory mechanism of Zfp36. Immunoblotting showed that pERK protein expression increased significantly in Zfp36-deficient cells compared with the control cells. In Zfp36-deficient MC3T3-E1 cells, inhibition of activated ERK/MAPK signaling with U0126 resulted in obviously enhanced ALP staining and significantly increased expressions of osteoblast differentiation markers Runx2 and Bglap (P<0.05). Conclusions ZFP36 is involved in the regulation of osteoblast differentiation of mouse BMSCs and preosteoblasts, and ZFP36 deficiency causes inhibition of osteoblast differentiation of the cells by activating the ERK/MAPK signaling pathway.

Objective To investigate the awareness of the Radiation Shielding Requirements for Radiotherapy Room–Part 2: Radiotherapy Room of Electron Linear Accelerators (GBZ/T 201.2—2011) among relevant practitioners in medical institutions as well as its implementation and application situation and collect relevant problems and suggestions for an evaluation of the scientificalness, standardization, and timeliness of the standard, and to provide a scientific basis for the further revision and implementation of the standard. Methods An online questionnaire survey was conducted among relevant employees in medical institutions providing medical linear accelerator radiotherapy across 22 provinces of China, which investigated the awareness, training, application, and revision suggestions related to GBZ/T 201.2—2011. The questionnaires were collected and analyzed. Results A total of 340 relevant practitioners filled out the questionnaire. Of the participants, 66.80% were physicists; 79.11% had an awareness of the standard; 56.18% ever participated in the standard-related training; but the survey results showed that the practitioners did not have a good knowledge of the standard’s content, and the training and promotion were not enough; 83.24% thought that the standard had been widely used; 17.60% thought that the standard needed to be revised; 76.76% thought that there was a need to add calculation examples; 88.82% thought that neutron shielding needed to be considered for the 10 MV X-ray accelerator room. Conclusion The standard has been widely known in the field of radiotherapy protection. With the development of radiotherapy technology, the standard should be revised to add calculation examples and consider neutron shielding in the 10 MV X-ray accelerator room. The standard is highly technical and difficult to grasp, so the promotion and implementation goals should be appropriate for different personnel groups, the training for employees at key posts should be strengthened, and the methods recommended in the standard should be uniformly used throughout the country.

Objective To analyze the clinical features of children with EV71 positive hand,foot,and mouth disease(HFMD)and EV71 vaccination,and to explore the relationship between the occurrence of severe disease and the preventive effect of EV71 vaccine.Methods From January 1,2020 to December 31,2022,the clinical data of 131 children with HFMD diagnosed with EV71 infection in Kunming Children's Hospital were retrospectively analyzed.The stool samples of patients with clinically confirmed HFMD were selected for enterovirus nucleic acid detection.The clinical data and EV71 vaccination status of children with universal enterovirus positive and EV71 positive HFMD were analyzed.Results Among the 131 positive cases detected,there were 116 mild cases and 15 severe cases.Among the 80 children who received phone consultations about their EV71 vaccine status,17 were vaccinated,and 63 were not vaccinated.The vaccinated children were all mild cases,while among the unvaccinated children,6 were severe cases.From 2020 to 2022,the period from April to September each year is the peak period for detecting EV71-positive hand,foot,and mouth disease(χ2 = 125.705,P = 0.000).The positive detection rate for children under 1 year old and over 5 years old was higher than that for children aged 1 to 5 years(χ2 = 8.765,P = 0.033),and there was no significant difference in the positive detection rate between boys and girls(χ2 = 1.221,P = 0.269).Conclusion EV71 vaccine is of great significance in reducing the occurrence of severe cases.Combined with the current low vaccination rate in Kunming,Yunnan Province,it is suggested that relevant institutions should continue to increase the publicity of EV71 vaccination.

Objective:To explore the present state of radiation protection in an operational large-sized irradiation facility and the distribution of incurred radiation doses in the controlled area under abnormal conditions, and to analyze the acompanied radiation risk.Methods:With an irradiation facility in operation as the research object, the radiation doses were measured using AT1121 X and gamma dose rate meters for the soruce both in working and storage. Thermoluminescent dosimeters (TLDs) were used to measure the dose distribution in an irradiation field under abnormal conditions. The radiation safety features were checked against the several relevant national standards, with the radiation risks evaluated.Results:The radiation dose rates were in the range of 0.09-0.11 μSv/h, lower than the environmental background level whether in storage or working. Under abnormal working conditions, the radiation dose values from high to low were 1.0-101.3 Sv, 32.7-514.0 mSv and 8.7-183.2 μSv in the irradiation field, respectively. At the outside maze, the doses were close to the background level.Conclusions:The protection features of the irradiation facility meet the requirements of the relevant national standards. Under abnormal conditions, radiation could cause serious damages to the persons staying in the irradiation field. These persons were suggested to access to maze as soon as possible to reduce the exposure time, and activate the emergency protection equipments to deescalate the 60Co source onto the well.

Objective : To analyze the expression and immune infiltration levels of the BMP7 gene ( BMP7) in e- sophageal squamous cell carcinoma(ESCC) ． Methods : Initially，in 274 cases of ESCC and 242 cases of normal tissues，the level of BMP7 was verified by immunohistochemistry ，and the relationship between the expression difference and the survival cycle and clinical pathological characteristics of patients with ESCC was explored，and BMP7 overexpression plasmid transfection of ESCC cells was established，and the effect of BMP7 on the biological behavior of ESCC cells was examined by CCK-8，Clone，and Transwell. Results : BMP7 expression in normal e- sophageal tissues was higher than that of ESCC(P＜0. 001) ，the expression level of BMP7 was correlated with the degree of differentiation of patients(P = 0. 006) and TNM staging(P ＜0. 001) ，and the survival of patients with high expression of BMP7 exceeded that of patients with low BMP7 (P = 0. 041) ，and the experiments of CCK-8 and Clone showed that the proliferation effect of cells in the overexpressed BMP7 group was lower than that of the control group．Transwell experiments confirmed that the cell invasion migration capacity of the overexpressed BMP7 group was less than that of the control one．The immune infiltration results showed that BMP7 was positively correlated with macrophages(P = 0. 008) and negatively correlated with γ-δT cells(P = 0. 028) ． Conclusion BMP7 is low in ESCC and associated with poor prognosis and immune infiltration levels in patients.

OBJECTIVE To establish a comprehensive and rapid m ethod for the a nalysis of chemical constituents as phthalides and organic acids in Angelica sinensis ，and to provide scientific reference for the quality evaluation and pharmacodynamic substance research of A. sinensis . METHODS The 70％ ethanol extract of A. sinensis was analyzed by ultra high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry （UPLC-Q-TOF/MS）. The determination was performed on ACQUITY UPLC BEH-C 18 column with mobile phase consisted of 0.1％ formic acid solution- acetonitrile（gradient elution ）at the flow rate of 0.3 mL/min. The column temperature was set at 30 ℃，and sample size was 2 µL. The ion source was an electrospray ion source ，using positive ion scanning mode ，and the mass scanning range was m/z 50-1 000. Capillary voltage was 4 000 V； atomizer pressure was 35 psi；cracking voltage was 135 V and the taper hole voltage was 65 V；the temperature of dry gas was 320 ℃；the flow of dry gas was 10 L/min and the flow of sheath gas was 11 L/min；collision energy were 20 and 40 V. Qualitative Analysis 10.0 software was used to obtain the retention time of compounds ，the accurate mass number of excimer ion peaks and secondary fragments. The compounds were analyzed by comparing with the mass spectra of the reference substance ，combined with relevant literature ，mass spectrometry cleavage law and database such as Chemspider ，MassBank，PubChem. RESULTS A total of 72 compounds were identified or deduced from A. sinensis ，including 55 phthalides，13 organic acids and 4 other constituents. CONCLUSIONS The established method is rapid and accurate for the identification of chemical constituents from A. sinensis ，such as organic acids and phthalides ，which provides an efficient and rapid analytical method for the comprehensive characterization of its chemical constituents.

Objective:To monitor and analyze the activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020. Methods:Totally 1 074 atmospheric aerosol samples were collected by high flow air sampler (SnowWhite) including 275 in spring, 266 in summer, 262 in autumn and 271 in winter and subjected to analysis by low background high-purity germanium gamma-ray spectrometery (ORTEC) to determine the activity concentrations of 7Be and 210Pb. Results:The activity concentrations of 7Be in atmospheric aerosol were from 0.56 to 14.84 mBq/m 3, with an avearage of 6.84 mBq/m 3, and from 0.01 to 9.37 mBq/m 3 for 210Pb, with an avearage 3.19 mBq/m 3. The differences in activity concentrations of 7Be and 210Pb in atmospheric aerosol among differernt seasons were statistically significant ( F=32.66, 93.93, P<0.05). Activity concentration of 7Be was highest in spring, followed by autumn, and lowest in summer and winter. Activity concentration of 210Pb ranged from winter, autumn, spring to summer in descending order. Conclusions:The activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020 fluctated within the range of normal level.