Baoan District Research Articles

Comparison of the Workday and Non-Workday Carbon Emission Reduction Benefits of Bikeshare as a Feeder Mode of Metro Stations

Bikeshare, as a convenient transport mode, can address the first- and last-mile travel needs of metro trips while generating many environmental benefits, such as reducing the use of environmentally unfriendly transport modes and lowering the carbon emissions of the urban transportation system. This paper takes bikeshare as a feeder mode of metro stations (BS-FMMS) as the research object and compares the spatial and temporal differences in the carbon emission reduction benefits of BS-FMMS on workdays and non-workdays by using the framework of BS-FMMS carbon reduction benefit analysis and the methods of time-series analysis, spatial aggregation analysis, and box plot analysis. The results show that the carbon emission reduction benefit of bikeshare has obvious morning and evening peaks on workdays, while it tends to be stable without obvious peaks during the day on non-workdays. From the perspective of spatial distribution, the carbon emission reduction benefits of BS-FMMS are more significant in the metro station areas in the south of Baoan district, the west of Nanshan district, the central of Longhua district, and the south of Futian district in Shenzhen city, and the metro stations where the carbon emission reduction benefits of the non-workday are greater than those of the workday are mainly concentrated in Nanshan district, Futian district, and Luohu district. There is a significant positive correlation between BS-FMMS ridership and carbon emission reduction. These findings can provide clear policy implications for the decarbonization development of urban transportation systems.

Value of cardiodynamicsgram in early diagnosis of patients with acute coronary syndrome

To explore the value of cardiodynamicsgram (CDG) obtained from electrocardiogram (ECG) data by radial basis functionradial basis function (RBF) neural network in early diagnosis of patients with acute coronary syndrome (ACS). Retrospective analysis method was used. Patients with chest pain as the main initial symptom in the emergency department of Baoan District People's Hospital of Shenzhen from October 2021 to September 2022 were enrolled. Baseline data were collected, including gender, age, smoking history, family history of coronary heart disease and history of hypertension, diabetes, hyperlipidemia, and atherosclerosis. The first 12-lead ECG was recorded after admission to the emergency department, and electrocardiodynamics analysis was performed to generate CDG. Receiver operator characteristic curve (ROC curve) was plotted to analyze the value of CDG and ECG in the early diagnosis of ACS and non-ST segment elevation ACS (NSTE-ACS). Sensitivity, specificity, area under the ROC curve (AUC), and 95% confidence interval (95%CI) were calculated. CDG and coronary angiography results of 3 patients with ACS with normal ECG were observed and analyzed. Non-ACS patients with normal ECG but positive CDG were followed for 30 days for adverse cardiovascular events. A total of 384 patients with chest pain were included, including 169 patients with ACS and 215 patients without ACS. The proportion of male (87.0% vs. 53.0%), smoking history (37.9% vs. 12.1%), hypertension (46.2% vs. 22.3%), diabetes (24.3% vs. 7.9%), hyperlipidemia (55.0% vs. 14.0%) and history of atherosclerosis (22.5% vs. 2.3%) in ACS group were significantly higher than those in non-ACS group (all P < 0.05). The ROC curve showed that the AUC of CDG diagnosis of ACS was higher than that of ECG [AUC (95%CI): 0.88 (0.66-0.76) vs. 0.71 (0.84-0.92)], the sensitivity was 92.8%, 78.6%, and the specificity was 83.3%, 64.2%, respectively. The AUC of CDG diagnosis of NSTE-ACS was higher than that of ECG [AUC (95%CI): 0.85 (0.80-0.90) vs. 0.63 (0.56-0.69)], the sensitivity was 87.1%, 61.3%, and the specificity was 83.3%, 64.2%, respectively. CDG of 3 patients with ACS with normal ECG showed disordered state, and coronary angiography showed ≥70% stenosis of major coronary branches. Of 215 non-ACS patients, 20 had a normal ECG but positive CDG, and 3 developed ST segment elevation myocardial infarction (STEMI) within 30 days, and 2 developed unstable angina (UA) within 30 days. CDG has high value in early diagnosis of ACS patients and is expected to become an important means of early diagnosis of ACS in emergency.

Eliminating mother-to-child transmission of hepatitis B virus: practice and progress in Baoan, a national pilot district of China

BackgroundWhile mother-to-child transmission (MTCT) of hepatitis B virus (HBV) remains a significant challenge in China, research investigating the effectiveness of the September 2017 pilot program to eliminate MTCT of HIV, syphilis, and HBV is limited. Baoan district, which has a higher-than-average rate of hepatitis B infection among pregnant women and strong support from the government, was one of six national pilot districts selected for the program. Therefore, this study aims to assess the progress and implementation of the elimination of MTCT of HBV in Baoan district over a period of 5 years.MethodsData was collected from the national information system for the prevention of MTCT, registration forms, and follow-up forms of pregnant women and their live births from 2018 to 2022. Joinpoint models were used to analyze changing trends over time, calculating annual percentage change (APC) and the corresponding 95% confidence interval (95%CI). Multivariate logistic regression models were used to analyze risk factors for HBV MTCT.ResultsFrom 2018 to 2022, the coverage of HBV screening during pregnancy increased from 98.29 to 99.55% (APC = 0.30, P = 0.012). The coverage of HBV early screening within 13 gestational weeks increased from 40.76 to 86.42% (APC = 18.88, P = 0.033). The prevalence of maternal HBV infection declined by an APC of − 3.50 (95% CI -6.28 ~ − 0.63). The coverage of antiviral therapy among high-risk pregnant women increased from 63.59 to 90.04% (APC = 11.90, P = 0.031). Coverage for timely administration of hepatitis B immunoglobulin, hepatitis B birth dose vaccine, and three-dose hepatitis B vaccination remained consistently above 97.50%. The coverage of post-vaccination serological testing (PVST) in high-risk infants was 56.15% (1352/2408), and the MTCT rate of HBV was 0.18%. Mothers with high-school education or below (OR = 3.76, 95% CI 1.04 ~ 13.60, P = 0.04) and hepatitis B e antigen (HBeAg) positivity (OR = 18.89, 95% CI 1.98 ~ 18.50, P = 0.01) had increased MTCT risk.ConclusionsThe implementation of comprehensive prevention strategies in Baoan district, including screening, treatment, and immunoprophylaxis, has proven effective in maintaining the MTCT of HBV at an extremely low level. However, it remains crucial to raise public awareness, specifically on the importance of improving the coverage of PVST for infants exposed to HBV.

The Development of Physical Education Curriculum Martial Arts Sports for the Nine Years Compulsory Education Stage of Guangdong Province

Background and Aim: Based on the lack of existing teaching materials. The objective of this research was to construct the Wushu physical education curriculum in the nine-year compulsory education stage. Materials and Methods: This study is a survey study. The population samples of this study are five nine-year compulsory education schools in Guangdong Province, namely Bayi Experimental School in Guangzhou, Xiaode School in Baoan District, Shenzhen, Zhongte Wenwu School in Zhuhai, Affiliated School of Foshan No. 4 Middle School, and Shantou Jinhua Overseas Chinese Pilot School. There are 369 students, 21 teachers, and 23 experts in the field of martial arts. Results: 1) The selection of martial arts teaching content in the teacher's book of the Cantonese Education Edition is better than that of the People's Education Edition, but there are still lack of martial arts etiquette content, lack of boxing characteristics, too single theoretical content, insufficient evaluation content and content system issues still need to be improved; 2) During the implementation of teaching, there are problems such as the teaching content in the teacher's book cannot meet the needs of the class hours, the difficulty of the teaching content is not appropriate, and the sequence of the teaching content is not properly arranged, which leads to certain influences on the selection of the actual teaching content by teachers; 3) In the actual teaching implementation, teachers should make full use of lesson preparation resources in the setting of teaching content, deeply understand the new curriculum standards; they should fully analyze the academic situation, and consider the sensitive period of students' physical fitness and students' psychology. The characteristics and learning basis; should fully reflect the integrity of the content, rationally set the theoretical content, and appropriately increase the traditional boxing types, to make the teaching content system more complete. Conclusion: In the first stage of the level, the study of theoretical knowledge such as martial arts is added. The second stage of the level emphasizes the connection between the past and the next. For the consolidation and improvement of the content of the previous stage, the practice of prescribed routines is added to strengthen the basic skills exercises. Level three adds to the learning of martial arts equipment. The fourth stage of the level enriches the theoretical knowledge and increases the practice of characteristic boxing and equipment at the level of movement technology.

Levels and trends of maternal death in Baoan district, Shenzhen, China, 1999–2022

China had achieved impressive success in improving maternal health, while the progress of reducing maternal mortality ratio (MMR) varied across regions. Some studies had reported maternal mortality from national or provincial perspective, but researches of the MMR on long-term period at the city or county level rare been reported. Shenzhen has experienced significant socioeconomic and health changes, reflecting the typical development of China's coastal city. This study mainly introduced the levels and trends of maternal death in Baoan district, Shenzhen from 1999 to 2022. Maternal mortality data were extracted from registration forms and the Shenzhen Maternal and Child Health Management System. Linear-by-Linear Association tests were used to evaluate the trends of MMR among different groups. The study periods were divided into three stages by 8-year interval and χ2 test or Fisher's test was used to test the difference in maternal deaths of different periods. During 1999-2022, a total of 137 maternal deaths occurred in Baoan, the overall MMR was 15.91 per 100,000 live births, declined by 89.31% with an annualized rate of 9.26%. The MMR declined by 68.15% in migrant population, with an annualized rate of 5.07%, faster than that in permanent population (48.73%, 2.86%). The MMR due to direct and indirect obstetric causes shown a downward trend (P<0.001) and the gap between them narrowed to 14.29% during 2015-2022. The major causes of maternal deaths were obstetric hemorrhage (4.41 per 100,000 live births), amniotic fluid embolism (3.37 per 100,000 live births), medical complications (2.44 per 100,000 live births) and pregnancy-induced hypertension (1.97 per 100,000 live births), the MMR due to the above causes all shown decreasing trends (P < 0.01), pregnancy-induced hypertension became the leading cause of deaths during 2015-2022. The constituent ratio of maternal deaths with advanced age significantly increased by 57.78% in 2015-2022 compared with in 1999-2006. Baoan district had made encouraging progress in improving maternal survival, especially in migrant population. To further reduce the MMR, strengthening professional training to improve the capacity of obstetricians and physicians, increasing the awareness and ability of self-help health care among elderly pregnant women were in urgent need.

Association between sleep-wake schedules and myopia among Chinese school-aged children and adolescents: a cross-sectional study

BackgroundThis study aimed to investigate the relationship between sleep-wake schedules and self-reported myopia in the pediatric population.MethodsIn this cross-sectional study in 2019, school-aged children and adolescents in the Baoan District of Shenzhen City were sampled using a stratified cluster sampling approach. Sleep-wake schedules of children were determined by a self-administered questionnaire. The age that participants first reported using myopia correction glasses or contact lenses was used to identify those with myopia. Pearson χ2 test was used to examine differences in myopia prevalence among participants with different characteristics. Multivariate logistic regression, adjusted for potential confounding variables, was applied to examine the relationship between sleep-wake schedule and risk of self-reported myopia, and a stratification analysis by school grade was also performed.ResultsA total of 30,188 students were recruited. In this study, the overall prevalence of myopia was 49.8%, with prevalence rates of 25.6%, 62.4%, and 75.7% for primary, junior high, and senior high school students, respectively. Students with irregular sleep-wake times reported a higher prevalence of myopia than those with regular sleep-wake times. Nighttime sleep duration of < 7 hours/day (h/d) (OR = 1.27, 95%CI: 1.17–1.38), no daytime nap (OR = 1.10, 95%CI: 1.03–1.18), irregular weekday bedtime (OR = 1.11, 95%CI: 1.05–1.17), irregular weekday wake time (OR = 1.21, 95%CI: 1.12–1.30), weekend bedtime delayed > = 1 h/d (OR = 1.20, 95%CI: 1.11–1.29, P < 0.001), weekend wake time delayed > = 1 h/d (OR = 1.11, 95%CI: 1.03–1.19), irregular sleep-wake time on weekdays (OR = 1.13, 95%CI: 1.07–1.19), and social jetlag > = 1 h (OR = 1.08, 95%CI: 1.03–1.14) were likely to be associated with increased risks of self-reported myopia after adjusting age, sex, grade, parental education level, family income, parental myopia, academic record, and academic workload. When stratified by school grade, we observed that nighttime sleep duration < 7 h/d, no daytime naps, and irregular sleep-wake time on weekdays were significantly associated with self-reported myopia in primary school students.ConclusionInsufficient sleep and irregular sleep-wake schedules can increase the risk of self-reported myopia in children and adolescents.

Research on the Innovative Mode of Promoting "Internet+" Grassroots Governance

The rapid development of information technology has brought the whole society into the information era of "Internet+", and the level of development of grassroots governance, as an important element of China's basic democratic political construction, is in a sense a manifestation of the overall level of social development. Shenzhen, as a special economic zone, is at the forefront of China's development in all aspects, and Baoan District in Shenzhen, the largest district in the city, has 3030 national high-tech enterprises and has become the district with the most national high-tech enterprises in Guangdong Province, and has been at the forefront of exploration and reform in grassroots governance. Therefore, this paper takes Baoan District of Shenzhen as an example to study the innovative mode of promoting Internet+ grassroots governance. This paper expounds the theoretical knowledge about "Internet+" grassroots governance, conducts a survey and research around the mode innovation of Internet+ grassroots governance in Shenzhen, and summarizes some of the problems of promoting "Internet+" grassroots governance in Baoan District. The paper summarizes some problems of promoting "Internet+" grassroots governance in Baoan District, and puts forward suggestions for promoting the innovative model of Internet+ grassroots governance.

Analysis of volatile organic components of organic solvents used in Bao'an District of Shenzhen

Objective: To understand the volatile organic components in the organic solvents used by enterprises in Baoan District, Shenzhen. Methods: From January to December 2020, a total of 541 organic solvent samples used by 86 companies were collected for volatile organic component analysis, and the main volatile components and high-risk occupational hazards in organic solvents used in different industries were analyzed. Results: A total of 201 volatile organic components were detected in 541 organic solvents. The top 5 components detected include xylene (29.76%, 116/541), toluene (21.81%, 118/541), methanol (20.70%, 112/541), n-hexane (14.79%, 80/541) and ethylbenzene (14.23%, 77/541). The detection rates of benzene, trichloroethylene, n-hexane, and 1, 2-dichloroethane, which were high-risk occupational hazards, were 2.40% (13/541), 3.70% (20/541), 14.79% (80/541), and 1.66% (9/541), respectively. The volatile components in organic solvents used in different industries was different. Benzene is more frequently detected in organic solvents used in the printing industry, trichloroethylene was more frequently detected in organic solvents used in the electronics industry, and n-hexane was more commonly found in organic solvents used in the electronics industry, printing and other industries, and 1, 2-dichloroethane has been more frequently detected in organic solvents used in the machinery industry. Conclusion: There are many types of organic solvents used by enterprises in Bao'an District, with complex components and differences in different industries.

Epidemiological Characteristics of COVID-19 and Effective Public Health Interventions in Shenzhen, China.

Objectives:This study aims to analyze and summarize the epidemic characteristics of coronavirus disease 2019 (COVID-19), and the public heath interventions in Shenzhen from 1 January 2022 to 4 April 2022, hoping to provide useful reference for resurgence.MethodsData were extracted from the website of Shenzhen Municipal Health Commission from 1 January 2022 to 4 April 2022. The number of new indigenous patients, imported patients, symptomatic and asymptomatic patients, age, gender, regional distribution, screening routes, and clinical subtype were analyzed. The public health interventions were summarized and described.ResultsThere have been 1,215 new indigenous cases and 1,447 imported cases in Shenzhen from 1 January 2022 to 4 April 2022. The age group of the indigenous cases range from 2 months to 92 years. The median age was 35.0. The male-to-female ratio was 1.13 (623:551). The number of symptomatic and asymptomatic patients were 930 (76.5%) and 285 (23.5%), respectively, without death. Shenzhen has experienced three outbreaks. Futian District has the large proportion of confirmed cases (55.8%), followed by Nanshan (13.5%), and Baoan District (13.5%). The indigenous confirmed cases were mainly screened from close contacts under quarantine observation (632 cases, 53.8%), key areas (304 cases, 25.9%), key crowds (93 cases, 7.9%), and communities (145, 12.4%). Among the imported cases outside the Chinses Mainland, China's Hong Kong had the largest number of confirmed cases (n = 1,368), followed by Singapore (n = 18), South Korea (n = 18), and Japan (n = 14). The Shenzhen government quickly implemented effective measures, including citywide screening, quarantine, tracking, classified management for different groups and the dividing epidemic-hit communities, villages into three regions (sealed area, controlled area, and prevention area), and expand the capacity of designated hospitals, etc., which effectively controlled the outbreaks. By 4 April 2022, no new local cases had been reported.ConclusionsThree novel COVID-19 outbreaks occurred in Shenzhen between 1 January to 4 April 2022, linked to importation from outside the Chinese Mainland and subsequently caused the local transmission. The measures of citywide testing–tracking–classified management by risk level have effectively controlled the epidemic and should be continued to prevent resurgence.

Correlation analysis of TCM syndrome characteristics and high risk factors of patients with colorectal polyps in Shenzhen: A case retrospective study

Objective: To analyze the characteristics of Traditional Chinese Medicine (TCM) asthenia- and sthenia-syndrome and its correlation with high-risk factors in patients with colorectal polyps in Shenzhen through case retrospective study Methods: 296 eligible patients hospitalized were collected in the Department of TCM in People’s Hospital of Shenzhen Baoan District from January 2016 to June 2021, and diagnosed with intestinal polyps, and divided into deficiency-syndrome, sthenia-syndrome and Asthenia-Syndrome Accompanied With Sthenia-Syndrome (ASASS). In addition, the correlation between syndromes and hyperglycemia, hypertension, hyperlipidemia and hyperuricemia was also analyzed. Results: There were 37 patients with ASASS, among which deficiency of vital energy and blood stasis accounted for the highest proportion. For patients with ASASS, the age difference among different syndromes was statistically significant (P&lt;0.05). The proportion of patients with hypertension and sthenia of liver yang was significantly higher than that of other syndromes (P&lt;0.05). Conclusion: Patients with colorectal polyps in Shenzhen area are mainly deficiency of vital energy and phlegm-wetness, and the pathological factors involve phlegm-dampness, blood stasis and stagnation of vital energy. Age and hypertension should be considered in the treatment of ASASS. Keywords: colorectal polyps; TCM syndrome; asthenia-syndrome accompanied with sthenia-syndrome; deficiency of vital energy; Shenzhen.

Hierarchical first aid training scheme for elementary and middle school students: the practices from the construction of "Baoan Model" social emergency medicine training

To share the implementation experience of hierarchical first aid training scheme for elementary and middle school students in Baoan District of Shenzhen City and evaluate its effect of training. During August 2018 and August 2019, elementary and middle schools students who participated in the first aid training held by emergency rescue training center of Baoan District were enrolled. Baseline information including the number of students, the number of attending tutors, the number of cardiopulmonary resuscitation (CPR) training models, automated external defibrillator (AED) models were recorded. According to hierarchical levels of three age, students received different courses with content from simple to hard: the course of elementary school students was consisting of dialing 120, smart animation on how to identify accidental damage, demonstration of AED and Hemlick techniques, CPR practise (40 minutes). The course of junior high school students was consisted of how to dial 120, how to identify accidental damage and simple disposal, application of CPR and AED, practice CPR and AED and Hemlick techniques (90 minutes). The course of high school students was consisted of how to dial 120, identify accidental damage and right disposal, identification of out-of-hospital cardiac arrest, the key-point of CPR and AED, practice CPR and AED, Hemlick techniques and hemostatic bandage (120 minutes). At the end of course, elementary school students were voluntary for skill assessment; junior high school students only were compulsory for skill assessment in small classes but not required in large classes, just for demonstration; additionally, the whole high school students were compulsory for skill assessment. The characteristics of first aid training students at different levels were collected in order to compare the differences on the usage of CPR training model and AED training model, the distribution of emergency resource, the ratio for passing examination. A total of 12 896 students and 2 086 training instructors took parted in 200 lists of first aid training courses, 8 557 CPR models and 8 493 AED models were used. On average, there are 65.27±5.61 students in each session, and 10.52±10.43 training instructors. There are 43.09±19.06 CPR training models and 42.77±18.61 AED training models. The mean ratio of student to tutor was 6.07±1.47, student to CPR model was 1.54±1.02, and student to AED model was 1.54±1.03. In the end of course, 10 494 students participated in the examination with the participation rate of 81.37%; 10 114 students passed the examination with the passing rate of 96.38%. Hierarchical analysis showed: compare to elementary school students, the average number of junior high school students in every training session significantly increased (cases: 69.94±8.77 vs. 58.69±6.12, P < 0.05), but the average number of high school students in every training session significantly decreased (cases: 57.35±5.79 vs. 58.69±6.12, P < 0.05). The proportion of instructors in junior high school students' training significantly reduced (5.94±1.39 vs. 6.48±2.02, P < 0.05). The examination ratio of junior high school students and high school students was increased significantly [81.07% (6 667/8 224), 100% (2 313/2 313) vs. 64.18% (1 514/2 359), both P < 0.05], but the ratio of passing the examination was significantly reduced [95.47% (6 365/6 667), 96.88% (2 241/2 313) vs. 99.60%(1 508/1 514), both P < 0.01]. This might be related to the low difficulty of elementary school students' assessment and the low proportion of compulsory examination. Hierarchical scheme is feasible for first aid training in elementary and middle school students, the content of course should be desighed from easy to hard. Synchronously, sufficient training instructors and training models should be equipped to ensure the quality.

Sleep status associated with psychological and behavioral problems in adolescents and children

Objective: To examine whether sleep status and social jet lag are related to the mental health behaviors in children and adolescents, providing a reference for preventing and improving children and adolescents' mental health behaviors. Methods: A large cross-section was conducted in Baoan District, Shenzhen, from April to May 2019. A total of 30 188 adolescents and children in grades 1-12 in 14 schools were included. The growth trajectory and health index questionnaire of primary and secondary school students were designed to evaluate the sleep status. Mental health behavior problems among students were accessed using the parents' and students' versions of the Strengths and Difficulties Questionnaire. After controlling for confounding factors of demographic variables, including gender, age, parental education level, academic performance, learning burden, and noise impact, a multivariate logistic regression model was used for statistical analyses. Results: The sleep duration of four grades students were 90.4％,90.1％, 98.2％, and 98.4％, respectively. 19.9％ did not have a post-lunch nap. 19.6％ had a wake-up delay of more than or equal to 2 h weekend morning. 35.1％ had an inconsistent bedtime and 15.5％ had an inconsistent awakening time. The multivariate logistic regression model showed that compared with 8-9 h, the sleep duration of elementary school juniors at night less than or equal to 7 h, 7-8 h increased the risk of psychological behavior problems. The sleep time more than 9 h was negatively correlated with psychological behavior problems. The sleep duration of elementary school seniors less than or equal to 7 h increased the risk of psychological behavior problems. The sleep duration of middle school and high school students less than or equal to 6 h increased psychological behavior problems. The ORs (95％CI) appeared as 2.53(1.85-3.47), 2.41(1.11-5.25), respectively. The ones with a sleep time more than 9 h also increased the risk, and ORs (95％CI) appeared as 2.37(1.40-4.01), 5.38 (1.79-16.1), respectively. Both the absence of post-lunch nap and the nap time less than 0.5 h were risk factors for psychological behavior problems in primary and middle school students. The nap time over 1-2 h was also a risk factor for high school students' psychological behavior problems. Waking up at irregular times in the morning, going to bed at varying times in the evening, and delaying getting up for more than or equal to 2 h on weekends were all risk factors for psychological and behavioral problems among primary and middle school students. The ORs (95％CI) of psychological behavior problems of elementary school juniors and seniors, middle school and high school students were 2.07 (1.45-2.97), 1.57 (1.09-2.26), 2.66 (2.06-3.44), 2.48 (1.96-3.15), respectively. Conclusions: Sleep duration, no post-lunch sleep, and daily intraindividual variability of sleep is positively associated with poor mental health. Additionally, social jet lag is associated with mental health problems in students. It is noted that delaying sleep within half an hour on the weekends of elementary school juniors is significantly associated with an increase in bad mental behavior.

The relationship between migration time and the prevalence of myopia of children and adolescents aged 6-18 years old in Shenzhen

Objective: To analyze the relationship between migration time and the prevalence of myopia of children and adolescents aged between 6 and 18 years old in Shenzhen. Methods: From April to May 2019, 26 618 children and adolescents from 14 schools in six streets of Baoan District, including Fuyong, Shajing, Xin'an, Xixiang, Songgang and Shiyan, were included in the study by using random cluster sampling method. The demographic characteristics, migration status, self-reported myopia, screen time in the last seven days, outdoor activities in the last one month and other information were collected through the questionnaire. The differences of myopia among children and adolescents with different characteristics were compared by χ2 test, and the relationship between migration time and the prevalence of myopia was analyzed by multivariate unconditional logistic regression model. Results: The age of 26 618 study participants was (12.37±3.49) years old, and the overall prevalence of myopia was 49.4%. Multivariate logistic regression analysis showed that after controlling for relevant confounding factors, compared with migrant children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for more than 6 years had a higher risk of myopia [OR (95%CI): 1.48 (1.14-1.92)]. After being grouped by phase of school, in the lower grade group of primary school, the children and adolescents of migrant workers who had migrated for more than 6 years had a higher risk of myopia compared with those of migrant workers who migrated for 1-2 years [OR (95%CI): 1.96 (1.20-2.74)]. In the high school group, compared with the children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for 3-5 years and ≥6 years had a higher risk of myopia [OR (95%CI): 6.03 (1.29-28.15) and 6.52 (1.51-28.11), respectively]. Conclusion: The migration time is related to the prevalence of myopia of the children and adolescents of migrant workers.

Epidemiology and pathogen study of an outbreak in clusters caused by human adenovirus type 4 in Shenzhen

Objective To analyze the epidemiological and pathogenetic characteristics of a community outbreak of acute respiratory tract infection by Human adenovirus serotype 4 (HAdV-4) at a primary school in Baoan district, Shenzhen, Feb.22-28, 2019. Methods All epidemiological and clinical information of these cases was collected through field interviews and medical records. Throat swabs samples were collected and tested for influenza virus in quantitative fluorescence PCR. Influenza virus negative samples were then PCR tested for 6 other common respiratory virus. HAdV-4 positive samples were further tested using hexon gene sequencing of adenovirus. The sequences were aligned with the GenBank data to determine the genotypes and draw the phylogenetic tree. Results The epidemic occurred in Class 1, Grade 2, with a total of 54 students, including 29 boys and 25 girls. After investigation, there were no cases of similar symptoms in other classes of the school. Totally 13 patients were diagnosed, including 7 boys and 6 girls, the incidence rate was 24.1%(7 / 29) and 24.0% (6/25), respectively. The clinical symptoms included fever (13 cases, 100.0%), sore throat (8, 61.5%), muscular ache (8, 61.5%) and cough (5, 38.5%). All the symptoms were mild, and there were no severe cases. All 5 throat swabs samples were adenovirus positive by PCR, and these positive samples were confirmed to be HAdV-4 subgroups E by DNA sequence analysis. Conclusion The acute respiratory infection outbreak was caused by HAdV-4. The sequence of the strain is highly homologous with sequences from other districts of Shenzhen and Chinese cities. 摘要：目的 分析2019年2月22—28日深圳市宝安区某小学一起急性呼吸道病毒感染聚集性疫情的流行病学及 病原学特点。 方法 采用流行病学个案调査表对疫情进行现场调査, 使用荧光定量 PCR 方法对采集的咽拭子标本进 行流感样病例病原学筛査, 筛査阴性标本进行6种常见呼吸道病毒核酸检测。对腺病毒核酸阳性的标本, 用腺病毒六 邻体基因作为靶基因进行序列扩增及测定, 测序结果在GenBank上进行序列比较, 确定其病毒亚型并进行系统进化分 析。 结果 疫情发生在二年级(1)班, 全班共54名学生, 男29名, 女25名。经调査该学校其他班级其余年级未出现相 同症状病例。该起疫情共发现病例13例, 其中男生7例, 女生6例, 男女学生罹患率分别为24.1%( 7 /29)和24.0% ( 6 /25)。临床特征为发热13例(100.0%), 咽痛8例(61.5%), 全身肌肉酸痛8例(61.5%), 咳嗽5例(38.5%), 症状均较轻, 无重 症病例。共采集5份咽拭子标本 , 经荧光定量PCR检测均为腺病毒核酸阳性 , 5份标本用分型引物检测并分析序列确 定均为腺病毒E亚属4型。 结论 此次急性呼吸道感染聚集性疫情由腺病毒4型引起, 毒株序列与深圳其他区、国内 其他城市分离的腺病毒4型毒株序列具有髙度同源性。

街区尺度城市内部动态度的量化——以深圳市为例

城市动态度反应城市土地利用/土地覆盖动态变化的剧烈程度，对其进行量化是理解城市景观变化和进行城市生态空间监管的基础。现有研究主要聚焦城市扩张引起的特定地类（如人工表面、植被等）的动态变化，缺乏对城市内部精细尺度上（如街区尺度）景观动态的研究。以深圳市为例，首先利用多等级道路数据划分街区，进而基于高分辨率卫星影像解译的土地覆盖数据，利用土地利用动态度和土地利用强度指数量化街区尺度城市内部动态度。研究结果表明：（1）深圳市城市内部动态度较高，2017-2018年期间，14.93%的街区发生了不同程度的变化，热点区域主要分布在南山区、宝安区、盐田区等。（2）街区的变化包括多种地类的转变，其中，林地转变为裸土最为常见，占比为12.59%。由城市更新引起的地类变化也较普遍，如其他不透水地表向裸土的转移和建筑到裸地的转变分别为6.20%、5.59%。此外，深圳市街区的土地利用强度也存在较大差异，表现为土地利用强度增加的街区多分布在城市外围，而土地利用强度降低的街区则多分布在城市内部。（3）街区动态度与街区大小之间呈现非线性关系，街区动态度随着街区面积的增大，先急剧下降，后趋于平缓。本研究揭示了深圳市城市内部街区尺度上土地覆盖的动态变化特征，可为城市规划和生态空间管理提供科学支撑。;Urban landscapes are highly dynamic. Understanding the within-city dynamics in land cover and land use is important. Previous studies have largely focused on the changes of specific land use type (impervious surface, urban vegetation etc.) resulted from urban sprawl on large or medium scales. However, research on quantifying the urban dynamics on block scale is lacking. Taking Shenzhen as a case study area, this paper aims to use the land cover thematic maps interpreted from very high-resolution remote sensing images to quantify the urban dynamics within city at street block level. The results showed that: (1) there was high dynamics at street block level in Shenzhen, which was manifested as that the blocks with dynamic changes account for 14.93%. The hotspots of degree of urban dynamics were distributed in Nanshan, Baoan and Yantian district. (2) The contribution of dynamic changes (CDC) was significantly different between different land use changes on block scale. For all blocks, the CDC of change from woodland to bare soil was the highest (12.59%). In addition, CDC of land use and land cover changes which mainly resulted from urban renewal was high. For example, CDC of changes from other impervious surface and building to bare soil were 6.20% and 5.59%, respectively. In addition, the land use intensity of different block was obviously different. The blocks with increased land-use intensity were mostly distributed in the periphery of the city, while the blocks with decreased land-use intensity were mostly distributed in the interior of the city. (3) The relationship between dynamics of block and block size was nonlinear. With the block size increasing, the dynamics of block decreased sharply and then the decreasing trend became flat. Our study revealed the characteristics of the land use dynamics at street block level in Shenzhen, and it would provide a reference for urban planning and ecological space management.

Childhood disability and its associated perinatal characteristics in Bao\u2019an district of Shenzhen, China

BackgroundDisability has become a public health issues in China and around the world. This study aimed to report prevalence of children with disability by gender, delivery mode, birth weight, gestational age, birth defect and impairment type in the past 15 years in Baoan District, Shenzhen.MethodsData of children with all types of disability from year 2004 to 2018 was obtained from the registry database of Baoan Disabled Persons Federation. Their perinatal information, including gender, delivery mode, birth weight, gestational age, birth defect were traced from Shenzhen Maternal and Child Health Management System and compared with the whole registered population live births information in this district. Data of children with disabilities were included to calculate the prevalence (%).ResultsAn overall prevalence of children disability was 1.02% in Baoan district, Shenzhen, in the past 15 years. The overall as well as mental disability prevalence rose from the first 5 years period (2004 to 2008) to the second 5 years of 2009 to 2013, and then dropped to the lowest level in the third 5 year of 2014–2018. Mental disability and intelligent disability accounted for the highest proportion. More than 70% of all kinds of the disabilities except mental disability were detected before 1 year old, 87% of the mental and intelligent disabilities were found before 3 years old. The Percentages of male, premature, low birth weight infants and children with cesarean, birth defect in disable children were higher than in whole population live birth children.ConclusionsThe overall prevalence of disability declined in the district after specific policy engagement. Mental and intelligent disabilities were still the most common disability in the district. The age of 0–3 years was an important period for early childhood detection and intervention.

Risk factors for severe hand, foot, and mouth disease infected with Coxsackievirus A6: A hospital-based case-control study.

Coxsackievirus 6 (CV-A6) has been emerging as another predominant serotype for severe hand, foot, and mouth disease (HFMD) in China, after the introduction of enterovirus 71 inactivated vaccine (EV71 vaccine) for 3 years. Data on the risk factors for severe HFMD infected with CV-A6 are limited. We interviewed the caregivers to collected data on HFMD patients who sought medical care in the People's Hospital of Baoan district, Shenzhen, from 2015 to 2017. Totally, 131 severe patients were frequency-matched by age and gender with 174 mild patients infected with CV-A6. Univariable and multivariable logistic regression analyses were conducted to analyze the risk factors for severe CV-A6 HFMD. The average age was 20.62 ± 14.18 months and 20.52 ± 12.76 months for severe and mild patients, respectively. Multivariate analyses indicated complications at birth (odds ratio [OR], 4.18; 95% confidence interval [CI]: 1.64-10.63), peak body temperature over 39°C (OR, 4.04; 95% CI: 2.29-7.10) and first-born child (OR, 2.17; 95% CI: 1.27-3.70) increased the risk of severe HFMD infected with CV-A6. Breastfeeding (OR, 0.52; 95% CI: 0.32-0.87), and washing hands after playing frequently (OR, 0.58; 95% CI: 0.34-0.97) were negatively associated with severe illness. Compared with HFMD with infection of EV-A71, complications at birth and first-born child were newly found to be associated with severe illness in HFMD patients infected with CV-A6.

Using a Bayesian spatiotemporal model to identify the influencing factors and high-risk areas of hand, foot and mouth disease (HFMD) in Shenzhen.

BackgroundThe epidemic of hand, foot, and mouth disease (HFMD) has become a severe public health problem in the world and has also brought a high economic and health burden. Furthermore, the prevalence of HFMD varies significantly among different locations. However, there have been few investigations of the effects of socioeconomic factors and air pollution factors on the incidence of HFMD.MethodsThis study collected data on HFMD in Shenzhen, China, from 2012 to 2015. We selected eleven factors as potential risk factors for HFMD. A Bayesian spatiotemporal model was used to quantify the influence of the factors on HFMD and to identify the relative risks in different districts.ResultsThe risk factors of HFMD were the population, population density, concentration of SO2, and concentration of NO2. The relative risks (RRs) were 1.00473 (95% CI: 1.00059–1.00761), 1.00010 (95% CI: 1.00002–1.00016), 1.00215 (95% CI: 1.00170–1.00232) and 1.00058 (95% CI: 1.00028–1.00078), respectively. The protective factors against HFMD were the per capita GDP, the number of public kindergartens, the concentration of PM10, and the concentration of O3. The RRs were 0.98840 (95% CI: 0.98660–0.99026), 0.97686 (95% CI: 0.96946–0.98403), 0.99108 (95% CI: 0.98551–0.99840) and 0.99587 (95% CI: 0.99534–0.99610), respectively. The risk of incidence in Longgang district and Pingshan district decreased, while the risk of incidence in Baoan district increased.ConclusionsStudies have confirmed that socioeconomic factors and air pollution factors have an impact on the incidence of HFMD in Shenzhen, China. The results will be of great practical significance to local authorities, which is conducive to accurate prevention and can be used to formulate HFMD early warning systems.

Spatial Distribution of Heavy Metals and Associated Risks in Sediment of the Urban River Flowing into the Pearl River Estuary, China.

Twenty-eight transects in six urban rivers located in the Qianhai area of Baoan District, Shenzhen, China, were selected to study the contamination of heavy metals in its sediment, reveal the spatial distribution of heavy metals in these rivers, and assess the ecological risk of heavy metals in the urban river sediment. The result showed that the concentration of heavy metals displayed considerable variation in the study area. The results showed that southern airport drainage river had exposure to high concentrations of Cu, Nanchang Chung exposure to high concentrations of Zn, Cr, and Pb, Gongle Chung exposure to high concentrations of Ni, and Xixiang River exposure to high concentrations of Hg. The results of correlation analysis and cluster analysis indicated that Cu had significant correlations with Zn and Cr respectively (P < 0.05). There was significant correlation, and the same cluster existed among Zn, Cr, and Pb (P < 0.01), whereas Hg was not significantly correlated with other metals. The potential risk of the six rivers could be sorted as Gushu Chung < Gongle Chung < Tiegang reservoir flood discharge river < Xixiang River (a), Nanchang Chung < and Southern Airport drainage river.

THREE-DIMENSIONAL SUBSIDENCE MONITORING OF RECLAMATION AREA BASED ON TS-INSAR TECHNOLOGY

Abstract. This study used the Time Series Interferometric Synthetic Aperture Radar (TS-InSAR) technology and the ENVISAT ASAR dataset obtained between 2007 and 2010 and the Sentinel-1A dataset from 2017 to 2019 to determine the subsidence in the Shenzhen reclamation area, and used ASTER GDEM V2 to remove the phase jump caused by spectral decorrelation between bursts. Based on the time series of land subsidence of the reclamation area, a three-dimensional subsidence model of the reclamation area was established. By comparing and analyzing the subsidence results of two sets of satellite time series in the reclamation area, the temporal and spatial evolution of land subsidence and the cause of land subsidence in the reclamation area were analyzed. The results show that the test results of time series ENVISAT ASAR and Sentinel-1A have good continuity in subsidence spatialtemporal variation: From 2007 to 2010, the land subsidence in most areas of Shenzhen reclamation area is relatively stable, and the area where subsidence occurs is mainly distributed in Baoan District, the maximum subsidence rate in Baoan District is −23.12 mm/year. From 2017 to 2019, land subsidence in the reclamation area showed a tendency to spread and spread from west to east. The subsidence characteristics of Nanshan District are the most obvious, and the maximum subsidence rate is −17.52 mm/year.