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.

We reported a case of irreducible indirect inguinal hernia caused by sigmoid colon cancer entering the right groin.The patient complained about a right groin mass for more than 60 years with progressive enlargement for 3 years and pain for half a month.Abdominal CT examination at admission showed rectum and sigmoid colon hernia in the right inguinal area and thickening of sigmoid colon wall.Electronic colonoscopy and pathological diagnosis showed sigmoid colon cancer.Therefore,the result of preliminary diagnosis was irreducible indirect inguinal hernia caused by sigmoid colon cancer entering the right groin.We converted laparoscopic exploration to laparotomy followed by radical sigmoidectomy and employed end-to-end anastomosis of descending colon and rectum in combination with repair of right inguinal hernia.The patient recovered well after operation and was discharged.
Colon, Sigmoid/surgery* ; Groin ; Hernia, Inguinal/surgery* ; Humans ; Laparoscopy ; Sigmoid Neoplasms/surgery*

Objective: To study the output dose of external beam radiotherapy in Beijing and analyze the cause of output dose  deviation.  Guidance  is  given  on  the  selection  of  measurement  methods,  calculation  formulas  and  parameters. Methods: During 2020, the output doses of medical electron accelerators, tomotherapy, cyberknife, and γ-knife were meas- ured based on the water absorbed dose calibration factor combined with the requirements in the IAEA TRS398 and TRS483 reports, and low-energy X-rays were measured based on the air kerma calibration factor combined with the requirements in the AAPM protocal. The output dose was measured and compared with the preset irradiation value. Results　: A total of 59 external beam radiation therapy equipments’s output dose were investigated.2 of the 49 accelerators’s absolute value of relative deviation between the system indication value and the measurement exceeded 3%; the deviation of other external beam radiotherapy equipments was less than 3%. Conclusion　 A unified method and multi-party quality control can ensure the accuracy of the output dose. In the routine operation of the equipment, the hospital should strictly implement periodic inspections to ensure accurate and reliable radiotherapy.

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.

Objective To analyze the performance differences of CT scanners with different detector rows between different manufacturers,and to provide the basis for the rational allocation and use of these CT scanners.Methods According to the result from the sentinel surveillance in 2014,a total of 148 medical institutions were equipped with CT scanners in 16 districts of Beijing,including general hospital(53),cancer hospital(5),TCM hospitals(25),children′s hospitals(2),community hospitals(30)and other specialized medical institutions(33).According to the principle of simple random sampling,40 medical institutions are selected,including 14 general hospitals,1 cancer hospital,7 Chinese medicine hospitals,1 children′s hospital,8 community hospitals and 9 other specialized medical institutions.A total of 141 CT scanners are selected from all CT sets of the selected medical institutions from 2012 to 2014.According to GB 17589-2011 X-ray computed tomography device quality assurance testing status test,four parameters related closely to image quality were tested,including CT value(water),noise,high contrast resolution,and low contrast detectability.Results No significant differences were found in CT value(water),noise and low contrast detectability among CT scanners produced by different manufacturers(P＞0.05),whereas high contrast resolution was found to have a remarkable difference(χ2＝34.706,P＜0.05).Significant differences were found in noise,high contrast resolution and low resolution detectability between the CT scanners with ＜64 detector rows and ≥64 detector rows(χ2＝6.978,10.040,15.973,P＜0.05).However,there is no difference in CT value(water)(P＞0.05).For less-than-64 detector row CT scanners,no significant difference was found in CT value(water),noise and low contrast detectability among different manufacturers(P＞0.05).only high contrast resolution differed remarkably(χ2＝9.941,P＜0.05).For more-than-or equal-to-64 detector row CT scanners,CT value(water)and noise have no differences among different manufacturers(P ＞0.05),whereas,there were significant difference in high contrast resolution and low contrast detectability(χ2＝31.376,32.967,P＜0.05).Conclusions There were a few differences in the performance testing of CT scanners from different manufacturers,and the less-than-64 detector row CT scanners have advantages in noise and low contrast detectability compared with the more-than-64 detector row CT scanners,whereas the latter have advantages in high contrast resolution and scanning time,allowing its wider application in medical institutions with more special diseases.

Objective To evaluate the role of minimum apparent diffusion coefficient(MinADC) values in peritumoral edema based on magnetic resonance diffusion weighted imaging in the differential diagnosis between primary central nervous system lymphoma(PCNSL) and glioblastoma(GBM).Methods ADC values in peritumoral edema were measured in 16 patients with PCNSL(diffuse large B cell lymphoma) and 31 patients with GBM(WHO grade 4) confirmed by pathology.Regions of interests were manually drawn on ADC maps on peritumoral edema regions to obtain the MinADC value.Independent samples t-test and receiver operating characteristic analysis were performed for statistical analysis.Results The MinADC value [(1.20-1.45)×10 mm/s,mean(1.35±0.68)×10 mm/s] in PCNSL was significantly higher than that in GBM [(0.95-1.31)×10 mm/s,mean(1.12±0.09)×10 mm/s](t=9.977,P=0.000).The area under the receiver operating characteristic curve was 0.986,and the cutoff value of MinADC was 1.245×10 mm/s for the differentiation between PCNSL and GBM,with the best combination of sensitivity(94.1%) and specificity(94.1%).Conclusion MinADC value can be a simple and effective measure for the differential diagnosis between PCNSL and GBM.

AIM:To investigate the protective effect of mucin 2(MUC2)on intestinal mucosa of colitis model mice,and to explore the correlation between the expression of anti-CBir1 flagellin antibody and MUC2.METHODS:The mice were randomly divided into normal control group,2,4,6-trinitrobenzenesulfonic acid(TNBS)group,lipopolysaccha-ride(LPS)+ovalalbumin(OVA)+TNBS group and ketotifen+TNBS group.The expression of MUC2 in colon tissue was determined by PAS staining and immunohistochemistry, and the anti-CBir1 antibody level in the serum of mice in each group was measured by ELISA.RESULTS:The scores of disease activity index and histological index in TNBS group were higher than those in normal control group(P<0.05).The scores in LPS +OVA+TNBS group were much higher than those in TNBS group(P<0.05).However, the values in ketotifen +TNBS group were lower than those in TNBS group (P<0.05).PAS staining showed a decrease in goblet cells in TNBS group.Compared with TNBS group,the colonic mu-cosa integrity in LPS+OVA+TNBS group was destroyed, and the number of goblet cells in ketotifen +TNBS group in-creased significantly.Immunohistochemical staining showed that the expression of MUC 2 in the intestinal tract of each mo-del group was basically consistent with the results of PAS staining.The serum anti-CBir1 antibody level in TNBS group was higher than that in normal control group(P<0.05), and that in LPS+OVA+TNBS group was significantly higher than that in TNBS group(P<0.05),whereas that in ketotifen +TNBS group was decreased slightly(P<0.05).CONCLU-SION:MUC2 plays a protective role in the pathogenesis of colitis in mice,and there is a negative correlation between the expression of MUC2 and the bacterial flagellin in the intestinal mucosa of mice with colitis.

Objective:To investigate the role of pro-inflammatory cytokine IL-17 involved in the pathogenesis of cytomegalovirus hepatitis in vivo.Methods:First of all,disseminated infection model was established.Then,mice were randomly divided into 4 groups:normal control group,MCMV-infected control group,IL-17 blockade group,and isotype control group.Mice were sacrificed on day 7 after infection.The levels of IL-17 protein were detected by Western blot.Hematoxylin eosin (HE) staining was performed to evaluate the pathologic change of the liver.Serum ALT levels were detected by a Roche DPPI biochemical analyzer.The level of serum IL-17 was measured by double antibody sandwich ELISA.The expressions of mRNA of IL-17R,IFN-γand IL-10 in liver were detected by RT-PCR.Results:Compared with MCMV-infected mice and isotype control,the blockade of IL-17 inhibited the expression of IL-17 protein in liver (P＜0.05).The degree of liver damage reduced obviously.The serum ALT was significantly lower [(146±15)vs (102±11)vs (37±12),P＜0.05].The level of serum IL-17 was relatively reduced[(719.76±6.06)vs (722.1±4.62) vs (707.53 ±8.58),P＜0.05].The expression of IFN-γmRNA [(0.56± 0.06)vs (0.55±0.13)vs (0.96±0.2),P＜0.05] and IL-10 mRNA[(0.55±0.073) vs (0.51 ±0.07) vs (0.903 ±0.18),P＜0.05] increased significantly,while that of IL-17R did not change apparently[(0.81±0.16)vs (0.89±0.38) vs (0.87±0.23),P＞0.05].Conclusion:The increased expression of pro-inflammatory cytokine IL-17 is involved in the pathogenesis of immune injury in cytomegalovirus hepatitis.The blockade of IL-17 is helpful to relieve the liver damage and improve the liver function.

Objective To compare the effect of different intestinal loop labeling methods under single balloon enteroscopy for ERCP. Method From June 2015 to May 2017, 36 cases of single balloon enteroscopy assisted ERCP patients, according to the study period divided into A, B, C three groups, In group A, the afferent loops were confirmed by titanium clips, labeled intestinal loops, and the B group was identified by methylene blue labeling and intestinal loops, and the C group was the control group, the operation time of the 3 groups was recorded (the starting time of operation, the time of reaching the nipple of the input loop or the time of the Roux-en-Y biliary anastomosis), the incidence of complications and the success rate of operation. Results The operation time was 42.17 min in group A and 59.83 min in group C, and there was significant difference between the two groups (P < 0.01),There was no statistically significant difference between group A and group B, group B and group C (P > 0.05), the complication rate and the operation success rate were not statistically different between the three groups (P > 0.05). Conclusion The operation time of the input loop at the time of ERCP assisted by single balloon enteroscopy has a clear advantage over the examination of the intestinal loop with a titanium clip.

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL. The present study provided a basis for future evaluation of these compounds as antibacterial agents.
Anti-Bacterial Agents ; chemistry ; isolation & purification ; pharmacology ; Calycanthaceae ; chemistry ; Escherichia coli ; drug effects ; Microbial Sensitivity Tests ; Molecular Structure ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Sesquiterpenes ; chemistry ; isolation & purification ; pharmacology ; Staphylococcus aureus ; drug effects