Objective: To analyze the epidemiological characteristics and influencing factors of norovirus aggregation in primary and secondary schools in Haidian District of Beijing from 2015 to 2018,and to provide scientific basis for the prevention and control of school aggregation epidemic situation. Methods: An epidemiological method was used to analyze the epidemic characteristics of norovirus aggregation in the primary and secondary schools in Haidian District of Beijing from January 2015 to December 2018. Multivariate Logistic was used to analyze the influencing factors of norovirus aggregation. Results: A total of 74 cases of norovirus aggregation in primary and secondary schools in Haidian District of Beijing from 2015 to 2018 were reported, involving 52 primary and secondary schools. Totally 1 291 suspected cases and a median of 12.5 cases of single epidemic were reported. Winter and spring were high incidence season. There was significant difference in the incidence rate of epidemic situation in primary and secondary schools(χ2=98.82, P<0.01). There was significant difference in the incidence rate between men and women(χ2=55.56, P<0.01). A total of 648 samples and 486 positive samples were collected, with a positive rate of 75.00%, mainly GⅡ virus, accounting for 87.45%. Multivariate Logistic regression showed that the scale of school(>2 000，1 000~2 000), student’s hand hygiene habit,requirement for medical care after the outbreak is the influence factor of the outbreak(OR=3.78，2.95，8.25，2.88). Conclusion Poor hand hygiene habits are the most important risk factors for the outbreak, so schools and parents should cultivate children to develop good hygiene habits of washing hands before and after meals, and timely isolation of cases found in schools is also an important measure to prevent and control the epidemic.

Objective To investigate the preliminary clinical application of anterior pedicle screws in treatment of the lower cervical spine injuries. Methods The study involved 22 patients with lower cervical spine injuries treated with anterior pedicle screw technique from January 2009 to December 2011.X-ray and CT images of the patients were taken postoperatively to evaluate whether the position,orientation and length of the screws were appropriate and whether there involved pedicle cortex perforation,transverse foramen or spinal canal invasion.MRI was also performed to ascertain the situation of decompression,the formation of epidural hematoma and the degeneration of cervical spinal cord.The improvement of JOA score was compared statistically. Results All the patients were followed up for 3-36 months ( mean,15.5 months).A total of 44 anterior lower cervical screws were implanted and all screws were inserted smoothly.All the patients had bone healing after average 4.5 months,which showed no loosening,prolapse or breakage of the screws or no loosening of the plate.One patient showed hoarseness postoperatively,which was probably due to the long-term distraction of recurrent laryngeal nerve.The symptom disappeared at around three weeks after neurotrophic support.Two patients complained of dysphagia postoperatively,and were informed of keeping a soft diet.The symptom was remarkably alleviated after three months or so.The X-ray films indicated satisfactory position of the implanted screws.Before discharge,the transaxial CT images showed that two screws perforated the medial pedicle cortex ( 1 ° ) and that two screws perforated the lateral cortex (1 °) and affected the medial margin of the transverse foramen.Before discharge,the MRI indicated obvious alleviation of the anterior spinal cord compression in all patients and a small amount of anterior epidural hematoma in four patients,with no obvious spinal cord compression.At 12 months after operation,the MRI showed significant improvement of spinal cord degeneration in three patients.JOA score was increased from preoperative (8.5 ± 0.7) to ( 14.5 ± 0.8 ) before discharge (P ＜0.01 ).JOA score was (15.7 ±0.7) at six months postoperatively,which was significantly improved as compared with that before discharge. Conclusions Anterior pedicle screw fixation is a reliable and safe method for reconstruction of the anterior lower cervical injuries.Surgical indications should be strictly controlled in its clinical application.

Objective: To understand the prevalence and associated factors of school bullying among primary and secondary school students in Haidian District, and to provide scientific basis for intervention plan. Methods: From September to October 2021, 1 906 primary and secondary school students in Haidian District were selected by stratified cluster random sampling for electronic questionnaire survey,an electronic questionnaire survey was conducted on students by using the questionnaire of the Student Health Status and Influencing Factors Questionnaire. Results: The prevalence of campus bullying among primary and secondary school students in Haidian District was 4.3%, of which primary school (7.6%) > junior middle school (4.1%) > vocational high school (2.5%) > senior high school (1.9%) ( χ 2=23.49, P ＜0.01), boys (5.5%) were more than girls (3.0%) ( χ 2=7.44, P ＜ 0.01 ), students from abnormal families (6.9%) were higher than students from normal families (3.9%) ( χ 2=4.24, P =0.04). Multivariate Logistic regression analysis showed that students in primary school had a higher risk of being bullied in school ( OR =2.13). Abnormal family ( OR = 1.07 ), smoking experience ( OR =2.28), experience of being beaten and scolded by parents( OR =2.49) and fighting behavior ( OR =1.84) were positively correlated with school bullying ( P <0.05). Conclusion Campus bullying is prevalent in primary and secondary schools in Haidian District, which warrents further attention of schools and education departments. Family school partnership and targeted prevention and intervention measures for key populations are expected.

Objective: To evaluated the application of General Provisions of Safety and Health for Writing Boards(GB 28231-2011), and to provide basis for the revision and improvement of the standard. Methods: From June to October 2018, a questionnaire survey was conducted among 852 people engaged in the evaluation, use and production of writing boards in 8 districts of Beijing, Liaoning and Jiangsu. The contents of the survey include the awareness, implementation of the standard and evaluating the use of various parameters in the standard by personnel from different institutions. Results: The overall awareness ratio of the standard among staffs from health, education and enter prise was 78.26%. For the nominal size of the writing board and the vertical distance between the lower edge and the platform, the reasonableness considered lower by health professionals(62.50%, 37.50%) than that of education professionals(90.00%, 90.00%) and enterprise staffs(90.00%, 90.00%)(P<0.05); For the frequency and reasonableness of the nine parameters such as gloss and adhesion, the perception of each institution were significantly different(P<0.05), with proportion of professionals in health lower than experts in education and enterprise. For the two parameters of color and light resistance, each institution considered the maneuverability was not strong(P>0.05). Conclusion Propagation and implement is still needed to strengthen comprehension, because different institutions have different understandings towards the standard. There are still some problems waiting to be solved, such as different standard limits, poor enforceability of two parameters which are writing board color and light resistance.

Objective: The objective was to identify the incidence of influenza-like syndromes and related health behavior factors among Beijing residents. Methods: From December 6, 2013 to January 16, 2014, we selected 150 villages or communities from 30 towns or streets as survey locations using a multi-stage random sampling method, and then conducted a cross-sectional study among 7 354 residents who aged 18 years or above and had live in Beijing for more than a half year using self-administered anonymous questionnaires, and totally 7 327 valid questionnaires are collected. The questionnaire consisted of demographic information, self-reported influenza-like syndromes in the past two weeks, and health behaviors. Multiple logistic regression models were used to identify the factors associated with self-reported influenza-like syndromes. Results: The mean (SD) age of the partcipants was 44.6 (15.2) years. Among them, 6.9% (506 cases) reported having influenza like illness during the past two weeks. The multiple logistic regression analysis indicated that regular physical exercise, optimal hand hygiene, and avoidance of going to the crowded places during respiratory infectious disease epidemics were significantly associated with a lower likelihood of reporting influenza-like syndromes, compared with those without regular physical exercises, without optimal hand hygiene, and not avoiding going to the crowded places, and the OR(95%CI) were 0.80 (0.66-0.97), 0.75 (0.57-0.99) and 0.80 (0.65-0.98), respectively. Conclusion Personal health behaviors were associated with the incidence of respiratory infectious diseases such as influenza in Beijing, and future interventions to improve personal hygiene behaviors are needed to prevent the spread of respiratory infectious diseases.

Objective To study the epidemiological characteristics of an outbreak caused by norovirus infection in a school in Haidian district,Beijing.Methods Basic information of the school and data related to patients in the fields survey were collected and analyzed descriptively.Laboratory tests were performed to test the stool and anal swab specimens of both patients and cooks as well as the environmental specimens.Risk factors related to the incidence were analyzed through a case-control study.Results A total number of 119 patients were identified in the school.Clinical symptoms were mild,mainly involving vomiting (94.1％,112/119),abdominal pain (46.2％,55/119),but no need of hospitalization.The average age of the student patients was 6.38,with minimum and maximum between 5 and 11.Patients were found in 22 classes,but mainly in grade 1 and class 7 where 35 patients were found (30.17％).A total of 134 specimens of rectal swabs and stool were collected,with 7 positive for norovirus and 6 for sappovirus.Salmonella,Shigella,lapactic Escherichia coli and Vibrio parahaemolyticus were not found in on dinner sets,residual foods,bottled water or in drinking fountains.Index on water hygiene was unsatisfactory in classrooms or dormitories where more cases were found.Accommodation,north-facing-classrooms,abnormal water hygiene indexes were found related to the occurance of the disease (P＜0.05).Conclusions The outbreak was identified a gastroenteritis infection,caused by norovirus with symptoms as vomiting and abdominal pain.This event reached the reporting standards of public health emergencies-level Ⅳ.Discovery and isolation of the first case was not timely while transmission of the disease might be water-borne.Surveillance programs on symptoms,disinfection of vomit and stool in places like nurseries and schools should be strengthened to prevent the norovirus outbreak.

Objective To investigate human exposure to live poultry (poultry feeding and purchasing) in the residents in Beijing and related factors during the second wave of avian influenza A (H7N9) epidemic during 2013-2014, and provide scientific evidence for avian influenza prevention and control. Methods A total of 7366 adults aged ≥18 years were selected through multi-stage stratified sampling in Beijing for a questionnaire survey. Logistic regression model was used to analyze the influence factors of human exposure to live poultry. Results The live poultry feeding rate and live poultry purchasing rate in residents in Beijing in the past year were 5.3%(95%CI:4.8%-5.8%) and 6.0% (95%CI: 5.5%-6.5%) respectively. Logistic regression analysis indicated that lower educational level of primary school and below, (OR=1.82, 95%CI:1.22-2.72);being farmer (OR=2.49, 95%CI:1.89-3.29) or being unemployed (OR=1.65, 95%CI:1.08-2.52);being non local resident (OR=1.54, 95%CI:1.10-2.16);living in suburban area (OR=2.36, 95%CI:1.77-3.16);having one child (OR=1.76, 95%CI: 1.42-2.17) or ≥2 children (OR=2.15, 95%CI: 1.43-3.22) in the family were the risk factors associated with feeding poultry compared with higher educational level of college and above, being employed, being local resident, living in urban area and having no child. And being farmer (OR=1.61, 95%CI:1.27-2.02);being non local resident (OR=1.76, 95%CI:1.31-2.35);living in suburban area (OR=2.05, 95%CI:1.61-2.61);having one child (OR=1.24, 95%CI:1.02-1.52) or ≥2 children (OR=1.78, 95%CI: 1.21-2.63) were the risk factors for purchasing live poultry. Conclusion Some residents living in Beijing still have exposure to live poultry, and targeted measures should be taken to reduce the exposure to poultry.

The application of artificial intelligence （AI） in medical diagnosis and treatment is becoming increasingly widespread， providing doctors and patients with more high-quality， efficient and personalized medical services. However， it also raised a series of ethical issues such as data security， algorithm transparency， responsibility definition， fairness and justice， doctor-patient relationships， and other aspects. Based on the combing of existing research results， this paper analyzed the research status of medical ethics in the application of AI in diagnosis and treatment， as well as expected that future medical ethics research can further explore the ethical issues of AI technology in medical treatment in greater depth， thus ensuring the rational application of AI in the medical field and maximizing the protection of patients’ rights and interests.