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 ensure the accuracy of gamma spectrometer in our laboratory for the analysis of radionuclides in samples and to improve the laboratory personnel’s ability to perform analyses of radionuclides. Methods Our laboratory had continuously participated in the national assessments of gamma spectrometry of radionuclides organized by the Chinese Center for Disease Control and Prevention. The samples were measured by a high-purity germanium gamma spectrometer (GEM-MX7080P4). An analysis was performed on the results of the gamma spectrometry assessments from 2014 to 2021. Results Our laboratory had an overall qualified rate of 100% (8/8) and an overall excellent rate of 39% (3/8) in the gamma spectrometry assessments from 2014 to 2021. The distribution ranges of RD, Z, U, and U_rel for 28 measurements involving radionuclides ²⁰⁸Tl, ²²⁸Ac, ²³²Th, ⁴⁰K, ²³⁸U, and ¹³⁷Cs were −11.82% to 5.97%, −0.59 to 0.30, 0.02 to 0.92, and 4.33% to 10.49%, respectively. Conclusion The methods used in our laboratory for gamma spectrometry of radionuclides are accurate and the testing reports issued by our laboratory are reliable.

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 establish a disease risk prediction model for the newborn screening system of inherited metabolic diseases by artificial intelligence technology.Methods:This was a retrospectively study. Newborn screening data ( n=5 907 547) from February 2010 to May 2019 from 31 hospitals in China and verified data ( n=3 028) from 34 hospitals of the same period were collected to establish the artificial intelligence model for the prediction of inherited metabolic diseases in neonates. The validity of the artificial intelligence disease risk prediction model was verified by 360 814 newborns ' screening data from January 2018 to September 2018 through a single-blind experiment. The effectiveness of the artificial intelligence disease risk prediction model was verified by comparing the detection rate of clinically confirmed cases, the positive rate of initial screening and the positive predictive value between the clinicians and the artificial intelligence prediction model of inherited metabolic diseases. Results:A total of 3 665 697 newborns ' screening data were collected including 3 019 cases ' positive data to establish the 16 artificial intelligence models for 32 inherited metabolic diseases. The single-blind experiment ( n=360 814) showed that 45 clinically diagnosed infants were detected by both artificial intelligence model and clinicians. A total of 2 684 cases were positive in tandem mass spectrometry screening and 1 694 cases were with high risk in artificial intelligence prediction model of inherited metabolic diseases, with the positive rates of tandem 0.74% (2 684/360 814)and 0.46% (1 694/360 814), respectively. Compared to clinicians, the positive rate of newborns was reduced by 36.89% (990/2 684) after the application of the artificial intelligence model, and the positive predictive values of clinicians and artificial intelligence prediction model of inherited metabolic diseases were 1.68% (45/2 684) and 2.66% (45/1 694) respectively. Conclusion:An accurate, fast, and the lower false positive rate auxiliary diagnosis system for neonatal inherited metabolic diseases by artificial intelligence technology has been established, which may have an important clinical value.

Objective:To investigate radionuclide content in soil at 19 spots in Beijing, in order to provide scientific basis for the accurate evaluation of the levels of radioactive contamination.Methods:GEM-MX7080P4 HPGe γ spectrometer was used to analyse the activity concentrations of radionuclide 226Ra, 232Th, 40K and 137Cs in all 38 soil samples from 16 districts of Beijing from 2017 to 2018. Results:The mean activity concentration of 226Ra, 232Th and 40K were 23.9 and 24.1 Bq/kg, 31.2 and 31.7 Bq/kg, 600 and 578 Bq/kg respectively for the two consecutive years. The mean activity concentration of 137Cs in the two years was 1.21 Bq/kg, with the highest values of 5.48 and 6.18 Bq/kg, about 4.5 times and 5.1 times the average values in those years. Conclusions:All the result are within the range of the values from previous Beijing municipal and countrywide survey of environmental background, with 137Cs in soil arising almost from the previous nuclear activities or nuclear incidents.

From July to August 2018, a survey on the awareness of diabetic foot screening was conducted using the online questionnaires posted on the WeChat group. From 107 trainees in General Practitioner Teacher Training Program of Beijing Xicheng District and 50 general practitioners working in Chinese Academy of Sciences, 145 valid questionnaires were received. All 145 participants worked in community health care settings, including 105 general practitioners, 76 had 10 to 20 years of service, and 98 had undergraduate degree. The survey showed that 75.9% (110/145) heard the diabetic foot screening and knew that screening should be done for all diabetic patients; 98.6% (142/145) knew that the screening should include medical history, foot skin, neuropathy, vascular status, and 73.1% (106/145) also knew that screening should include the foot bone, joint deformities and footwear selection; 21.4% (31/145) had participated in training related to diabetic foot screening. It is suggested that the awareness and knowledge of diabetic foot screening among Beijing community medical personnelare not sufficient, and more training opportunity is necessary for them.

A well - established residency standardized training system is crucial for cultivating qualified general practitioners(GPs). The syllabus has regulated the goals, objectives, contents and forms of training, but not proposed the concrete and effective teaching and assessment models. This article reflects the existing problems in GP training regarding teaching faculty,rotation plan, outpatient teaching, feedback and evaluation mechanisms as well as the assessment methods and contents,the article also gives specific suggestions for future improvement in order to train competent GPs.

Objective: To investigate the application value of Information-Motivation-Behavioral Skill Model (IMB)-based continuing care on the recovery of nerve function and life quality in patients with stroke after thrombolytic therapy. Methods: Stroke patients who underwent thrombolytic therapy were randomly assigned to IMB group(35 cases) and control group(35 cases) according to the method of random number table. The control group recieved routine thrombolysis nursing, IMB group was given IMB-based continuing care. After six months of intervention, nerve function was evaluated by National Institute of Health Stroke Scale(NIHSS) and Modified Rankin Scale(MRS), the active ability was performed by Fugl-Meyer Assessment Scale(FMA) and Barthel Index(BI), the quality of life was assessed by the item short from health survey(SF-36), respectively. Results: Before intervention, the scores of NIHSS, MRS, FMA, BI, SF-36 between two groups was no significant difference (P>0.05). After three and six months of nursing, the NIHSS, MRS was (7.84±2.20), (5.00±1.60) points and (3.48±0.84), (3.07±0.69) points in IMB group, and (9.75±1.82), (8.21±1.37) points and (4.06±1.08), (3.91±0.71) points in control group, there was significant difference between two groups (t =2.417-8.647, P<0.01 or 0.05). After one, three and six months of intervention, FMA was (65.86±5.67), (76.41±8.47), (78.79±8.58) points, BI was (46.29±7.29), (58.09±10.20), (67.50±9.44) points, SF-36 was (33.13±4.64), (43.09±6.70), (49.83±8.56) points in IMB group, (58.53±8.92), (64.47±7.56), (71.81±8.90) points, (42.47±5.67), (48.74±5.39), (56.03±6.55) points and (29.63±4.06), (35.91±5.93), (41.02±9.05) points in control group, there was significant difference between two groups (t =2.333-5.972, P< 0.05). Moreover, in the repeated measures ANOVA showed the differences of NIHSS, MRS, FMA, BI, SF-36 were statistically significant for the group by time interaction(F=13.556-133.994, P<0.05). Conclusions IMB-based continuing care can promotes the recovery of nerve function and improves the quality of life in patients with stroke after thrombolytic therapy.

OBJECTIVE: To explore the prevalence and characteristics of chromosomal abnormalities in abortuses during early pregnancy with single nucleotide polymorphism microarray (SNP-array). METHODS: For 520 abortuses, copy number variations (CNVs) in chorionic villi were analyzed with SNP-array. RESULTS: In 510 (98.1%) of the samples, the analysis was successful. Among these, 57.6% (294/510) of the samples were found to harbor clinically significant chromosomal abnormalities. 38.8% of the samples (198/510) had a normal result. 2.4% (12/510) of the samples harbored benign CNVs, and 1.2% (6/510) harbored variants of uncertain significance (VOUS). Aneuploidies, polyploidies, pathogenic CNVs and uniparental disomies (UPD) had accounted for 75.2% (221/294), 13.9% (41/294), 8.2% (24/294), and 2.7% (8/294) of the samples, respectively. 45,XO was the most common finding, which was followed by trisomy 16 and trisomy 22. 69,XXY was the most common polyploidy. CONCLUSION Chromosomal abnormalities are the main cause for early miscarriage, among which aneuploidies are most common. The prevalence of aneuploidies is significantly increased among women over 35. SNP-array analysis has the advantage of high success rate, high resolution and great accuracy, but the clinical significance of microdeletions/microduplications found by SNP-array can be difficult for interpretation.
Chorionic Villi ; Chromosome Aberrations ; Chromosome Disorders ; DNA Copy Number Variations ; Female ; Genetic Testing ; Humans ; Karyotyping ; Polymorphism, Single Nucleotide ; Pregnancy

This research summarized the exploration of English salon teaching on students in Department of General Practice,Peking University Health Science Center,illustrating thatthis teaching method was helpful to improve the students' English proficiency and theory of medicine,to promote communication and cohesion of the department,and to enhance the GP concept and competency.Based on the existing problems of English salon teaching,this research put forward the corresponding countermeasures so as to provide optimizing reference for teaching of GP,which included:(1)To encourage students to be active to participate inEnglish salon,correct the students' learning attitude and improve their learning methods,pay attention toteaching skills and take advantage of situational dialogue training methods;(2)To cultivate students' clinical thinking of diagnosis and treatment,urge the students to refer toliterature in time,takenotes and solve problemsas appropriate,as well as to promote supervisors' participation;(3)To recommend English salon teaching as an extension for thedelayed case-sharing.