Objective: To explore the association between breastfeeding and the type of obesity in children and adolescents, and to provide a theoretical basis for the identification and intervention of influential factors of different types of childhood obesity. Methods: Using stratified cluster sampling method, 93 primary and secondary schools in 7 provinces and cities in China were selected for physical examination and questionnaire surveys. Totally, 30 437 primary and middle school students aged 7-17, with completed information, were selected. A multivariable Logistic regression model was used to analyze the association between breastfeeding and different types of obesity. Results: The breastfeeding rate of students was 69.8%. The rates of general obesity, simple abdominal obesity, and combined obesity in the breastfeeding group were 7.1%, 3.9%, and 18.7%, the non-breastfeeding group were 7.0%, 4.7%, and 19.5%. The differences were statistically significant(χ2=14.04,P<0.01). Univariate analysis found that breastfeeding significantly reduced the risk of simple abdominal obesity in children and adolescents(OR=0.81,95%CI=0.72-0.92,P<0.01) with normal(BMI non-overweight and obesity and waist Conclusion Breastfeeding is a protective factor for children with simple abdominal obesity and combined obesity, and the rate of breastfeeding in China should be further improved.

Objective: To explore the relationship between one-child and low height level classification among children and adolescents, and the effects of fruits, vegetables and physical activities on this association, and to provide as cientific reference for probing into and improving the differences of their height level between one child and child with siblings. Methods: Using stratified cluster sampling method, 93 primary and secondary schools in 7 provinces and cities in China were selected for physical examination and questionnaire surveys. A total of 40 978 primary and middle school students aged 7-17 were selected. A multilevel Logistic regression model was used to analyze. Results: Univariate analysis found that being one-child was less likely to be classified as low height level(OR=0.63, 95%CI=0.58-0.67); the multilevel model also found that the probability that one-child being at low height level was still lower(OR=0.78, 95%CI=0.73-0.85), and daily vigorous-intensity physical activities ≥1 h (OR=0.92, 95%CI=0.85-0.99) and daily vegetables and fruits intake ≥5 servings (OR=0.83, 95%CI=0.75-0.92) could also reduce the probability of being at low height level. Hierarchical analysis found that when vegetables and fruits intake and physical activities time were sufficient, there was no longer a significant difference in the height level classification between one-child and child with siblings(P>0.05). Conclusion Being one-child could be a protective factor for the height level classification of children and adolescents. Adequate intake of vegetables and fruits and time of vigorous-intensity physical activities could fill the gap of height level classification between of being one-child and child with siblings. Effective behavioral intervention measures should be taken to protect the healthy growth of height among children and adolescences.

Objective: To evaluate the association of short-term fine particulate matters (PM2.5) exposure and blood pressure in children and adolescents. Methods: A total of 144 813 junior and senior middle school students who participated in the physical examination in the 2017-2018 academic year in a northern city of China, with complete record of demographic characteristics, blood pressure and no history of heart and other important organ diseases were selected as the study subjects. Data on PM2.5 and other pollutants and meteorological data were obtained from the nearest air quality and meteorological monitoring stations of each schools. A generalized linear mixed effect model was used to analyze the association between short-term exposure of PM2.5 and blood pressure. Results: The 6 day average concentration of PM2.5 (lag05) increased by 10 μg/m 3 was associated with an increase of 0.177(95%CI=0.148-0.207)mm Hg (1 mm Hg=0.133 kPa) in systolic blood pressure and 4.4%(OR=1.044, 95%CI=1.030-1.058) increase of the prevalence of high systolic blood pressure. And it was also associated with -0.021(95%CI=-0.040--0.002)mm Hg decrease in diastolic blood pressure, but had no significant correlation with the prevalence of high diastolic blood pressure. In general, a 10 μg/m 3 increase of PM2.5 was associated with 3.3% increase in the prevalence of high blood pressure (OR=1.03, 95%CI=1.02-1.05), and difference of boys and girls were found in different lagged days (P<0.05). Conclusion Short-term exposure of PM2.5 is associated with increased systolic blood pressure and prevalence of high blood pressure among children and adolescents. Attention should be paid to the prevention of short-term exposure of PM2.5 to protect the health of children and adolescents.

Objective: To analyze the association between short term PM 2.5 exposure and high blood pressure in adolescents and its modification effect of overweight and obesity, and to provide a reference for the refined management of students physical health and the scientific prevention and controlling of air pollution. Methods: A total of 148 956 junior high school students and senior high school students who passed the annual physical examination data of middle school students in Beijing from 2017 to 2018 were selected; The inverse distance weighted interpolation method was used to get the meteorological elements and air quality of the research area; Linear mixed effect model was used to estimate the cumulative lag effect of short term PM 2.5 exposure on systolic and diastolic blood pressure within 7 days, and analyze the modification effect of overweight and obesity on the association between short term PM 2.5 exposure and high blood pressure in adolescents. Results: From September 1, 2017 to June 30, 2018, the average concentration of PM 2.5 was (56.53±45.85)μg/m 3; The detection rate of overweight and obesity was 34.22%, and the detection rate of high blood pressure was 8.03%. The cumulative lag effect of PM 2.5 on systolic blood pressure in overweight and obesity group was the largest at lag07, that is, the daily average concentration of PM 2.5 increased by 10 μg/m 3 was significantly correlated with higher systolic blood pressure ( OR =1.05,95% CI =1.03-1.07); the cumulative lag effect of PM 2.5 on systolic blood pressure in non overweight and obese group was the largest at lag05, that is, the daily average concentration of PM 2.5 increased by 10 μg/m 3 was significantly correlated with higher systolic blood pressure ( OR =1.04,95% CI =1.02-1.06). Short term exposure to PM 2.5 did not affect the high diastolic blood pressure in adolescents. Overweight and obese adolescents were more susceptible to high blood pressure caused by short term PM 2.5 exposure within 3 days of cumulative lag (lag01-lag03). Conclusion The short term exposure of PM 2.5 has a significant positive correlation with adolescent blood pressure, and shows a lag effect. Overweight and obese adolescents have higher blood pressure after PM 2.5 short term exposure.

Objective: To analyze the relationship between short term exposure of PM 2.5 and the vital capacity of children and adolescents and the modification effect of overweight and obesity, and to provide a scientific reference for appropriate outdoor activities and strengthening prevention of air pollution. Methods: A total of 1 036 273 students who qualified in the annual health examination data of primary and secondary school students in a city from 2017 to 2018 were selected; the meteorological factors and air quality of the study area were obtained by inverse distance weighted interpolation method; the generalized linear mixed model was used to estimate the individual lag effect and average lag effect of PM 2.5 short term exposure on lung capacity with in 7 days, and to analyze the modification effect of overweight and obesity on the relationship between short term PM 2.5 exposure and vital capacity in children and adolescents. Results: From September 1, 2017 to June 30, 2018, the average PM 2.5 concentration in this city was 66.36 μg/m 3, the detection rate of overweight and obesity was 33.38%, and the average lung capacity was (2 286.72±956.77)mL. The single lag effect of PM 2.5 on vital capacity was the biggest when lag6, the average daily PM 2.5 concentration increased by 10 μg/m 3 and the decrease of vital capacity of children and adolescents by 2.81(95% CI =2.60-3.03)mL. The average lag effect of PM 2.5 on lung capacity was the largest when lag07, the average concentration of PM 2.5 sliding was significantly correlated with the decrease of lung capacity of children and adolescents by 5.82(95% CI =5.37-6.27)mL every 10 μg/m 3 increase. The prevalence of PM 2.5 short term exposure to pulmonary capacity decreased in overweight and obese children and adolescents was higher ( P ＜0.01). Conclusion The short term exposure of PM 2.5 has a significant negative correlation with the lung capacity of children and adolescents, and there is a lag effect. The decrease of the vital capacity of overweight and obese children and adolescents after PM 2.5 short term exposure is more significant.

The national health industry standard (WS/T 610-2018), 'the reference of screening for elevated blood pressure among children and adolescents aged 7-to 18-years-old’, plays a significant role in the standardization of the blood pressure evaluation, the early detection of high blood pressure, and the early intervention of hypertension and other chronic non-communicable diseases among Chinese children and adolescents. This standard gives screening thresholds for blood pressure assessment of children and adolescents in different genders, ages, and heights. Given the complexity of applying this standard, it is error-prone and less efficient to evaluate blood pressure one by one or program this procedure. Therefore, this study provides a SPSS package based on the standard for researchers to download and use, combined with specific cases to guide the use of this package to evaluate the blood pressure of children and adolescents step by step, which could empower researchers to accurately and efficiently conduct blood pressure screening for children and adolescents in China.

Plastic pollution has become a global environmental issue, making it necessary to explore the environmental disposal technology for plastic waste. Recently, we and other researchers have individually found microorganisms or enzymes from nature that can degrade synthetic plastic. These findings indicated that the capability of these microorganisms or enzymes to degrade plastic could be used for the disposal of plastic waste. Polyurethane (PUR) was one of the most used general plastic and its plastic waste occupied 30% of the total volume of different plastic waste. This review tried to provide a comprehensive summary of the researches on microbial degradation of PUR plastic in the past 70 years since its invention, and focused on the PUR-degrading fungi, bacteria, genes or enzymes, degradation products and the corresponding biological disposal technologies. We finally proposed the key scientific challenges on the development of high efficient biological disposal for PUR waste in the perspective researches.