Objective:To explore the relations among screen-based sedentary behaviors ( SSB) , family factors and body mass index ( BMI) of children, and to study how family factors have effect on BMI through influencing SSB. Methods:A total of 1 846 students aged 7-11 years from 12 primary schools in one district of Beijing were included. Their body weight and height were measured to calculate the BMI. The time of SSB and family factors were investigated by using questionnaires. The time of SSB was the total time of watching TV and videos, playing computer games and iPad each day during the past 7 days recalled by children. The family factors included the parents’ education, occupation, the parents’ time of SSB, whether the parents told their child the harm of SSB, the parents’ time limit for the children’ s SSB. The parents’ education and occupation were used for calculating the family socioeconomic score. Results:The median time of SSB for children was 1 hour/day, and the interquartile range was 1 hour/day. The BMI of the children with the parents’ time limit for the children’ s SSB less than 120 min/day were smaller than the children with the parents’ time limit not less than 120 min/day, in both the boys (1. 63 kg/m2,P<0. 001) and the girls (0. 85 kg/m2, P=0. 004). The family socioeconomic score, the parents’ SSB time, whether the parents told their children the harm of SSB were not related to the children’ s BMI . The mediation effects of SSB time for children on the association between the parents’ time limit for the children’s SSB and BMI were-0. 222 kg/m2(95%CI:-0. 432, -0. 095) for boys and-0. 187 kg/m2 (95%CI: -0. 507, -0. 049) for girls , which accounted for 13. 67% of the total effects for boys and 22. 11% for girls. Conclusion:The parents’ time limit for the children’ s SSB has effect on their BMI through influencing their SSB time. Parents’ supervision on the behaviors of children produces larger benefit for BMI than health education conveyed by parents. Therefore, parents’ participation in su-pervising the behaviors of children are indispensable for preventing and controlling childhood obesity.

Objective To retrospectively study the quantitative features and diagnostic value of 3-dimensional shear wave elastography (3D-SWE) in breast lesions.Methods A total of 198 consecutive women with 198 breast lesions (125 malignant,73 benign) were included,who underwent conventional ultrasound (US) and 3D-SWE before surgical excision.Quantitative parameters of transverse planes,sagittal planes and coronal planes were calculated,including maximum elasticity (Emax-w),mean elasticity (Emean-w),standard deviation (Esd) of the whole lesion and ratio between the stiffest elasticity (Emean-s)in the lesion and the fatty tissue (Eratio).Area under ROC curve(AUC) for combination of quantitative parameters and US were calculated.Results The AUC,sensitivity and specificity for US were 0.919,88.0％ and 78.1 ％,respectively.In the total 198 lesions,Emax-w,Emean-w,Esd,Eratio and Emean s were significantly lower in coronal planes than those in transverse and sagittal planes (all P ＜0.001).AUC for combination of each quantitative parameter and US were significantly higher than those of US (all P ＜0.05),except Emean-w of transverse plane,while there was no significant difference among the three orthogonal plane (P＞0.05).Sensitivity significantly increased by combining US with Emean-s,Eratio (transverse,sagittal and coronal planes),Emean-w (coronal and sagittal planes) or Esd (coronal and transverse planes) (all P＜0.05).Combination of US and Emean w of coronal plane yielded significantly higher sensitivity than those of transverse and sagittal planes.Conclusions Combination of quantitative features of 3D-SWE and US can significantly increase diagnostic accuracy and sensitivity in breast lesions.Emean-w of coronal plane yields the highest sensitivity.

Objective To retrospectively study the anisotropy of shear wave elastography (SWE)quantitative parameters of breast lesions,and the correlation with histopathology.Methods A total of 281 consecutive women with 281 breast lesions (179 malignant,102 benign) were included,who underwent conventional ultrasound (US) and 2D SWE before surgical excision.Three acquisitions each for transverse and longitudinal planes were obtained,and maximum elasticity (Emax),mean elasticity (Emean),standard deviation (Esd) of the whole lesion and ratio between the elasticity in the mass and the fatty tissue (Eratio)were recorded.Anisotropic difference (AD) and anisotropy factors (AF) were calculated,and correlation with histopathology was analyzed.Results The average Emax,Emean and Esd of transverse planes were significantly higher than those of longitudinal planes.AF showed positive correlation with quantitative elasticity (Emax,Emean,Esd and Eratio) (P =0.000),and was significantly higher in malignant lesions than that in benign besions (P =0.000).AUC of AF was significantly higher than that of AD (P ＜0.001).AF was significantly higher in invasive ductal carcinoma than that in ductal carcinoma in situ.Higher AF was associated with higher histopathological grades of invasive ductal carcinoma (P =0.000),and correlated with ER/PR(+).Conclusions Anisotropy of SWE is an indicator of malignancy of breast lesions,and is of predictive value for prognosis in breast cancer.

Objective To investigate the influence of breast pure mucinous carcinoma size on sonographic characteristics and diagnostic accuracy.Methods Sonographic characteristics of 101 breast pure mucinous carcinoma in 1 00 patients were analyzed retrospectively.All lesions were divided into three groups according to maximum diameter at ultrasound.These were group Ⅰ with lesions less than 20 mm,group Ⅱwith lesions greater than or equal 20 mm,less than 40 mm,and group Ⅲ with lesions greater than or equal 40 mm.The relationship between lesions size and ultrasound parameters were analyzed.Results There were 38 lesions in group Ⅰ,52 lesions in group Ⅱ and 1 1 lesions in group Ⅲ.The patients age in group Ⅲwere older than that in group Ⅰ(F=3.442,P =0.036).Among these sonographic appearances,only shape (χ2=9.813,P =0.005)and blood flow (χ2=27.952,P =0.000)indicated significant differences.The accuracy of ultrasound diagnosis of breast cancer was 85.1%,the smaller the lesions were,the higher misdiagnosis rate the lesions were.Conclusions With lesions size increased,the lobular and internal blood flow of pure mucinous carcinoma increased.More smaller the lesions were,more higher misdiagnosis rate of lesions were.

Objective To investigate the value of ultrasound-guided diffuse optical tomography (US-guided DOT) to predict clinical efficacy of breast cancer neoadjuvant chemotherapy (NAC).Methods Eighty-eight breast cancer patients with 93 lesions were included.Pre-and post-last chemotherapy,the size,total hemoglobin concentration (THC) of each lesion were measured by ultrasonography (US) and US-guided DOT.Based on the guidelines to evaluate the response to treatment in solid tumors,the lesions of treated breast cancer patients were divided into 4 types of responses to NAC:complete response (CR),partial response (PR),stable disease (SD),and progressive disease (PD).Efficient groups include CR and PR groups.Results As expected,no significant difference was found in size and THC for untreated lesions (all P ＞0.05).However,for the treated lesions(P =0.001),THC,pre-vs post-treatment size changes (△Size％) (P =0.002) and THC changes (△THC％) (P ＜0.001) were significantly varied among CR,PR,SD,PD groups.When compared with pre-treated,tumor sizes after treatment were changed significantly in all CR(P ＜0.001),PR(P ＜0.001),SD (P =0.023) and PD (P =0.001),while significant change of THC was only found in CR(P ＜0.001),PR(P ＜0.001) and SD (P =0.002).When △THC％ =23.9％ as the threshold for prediction of NAC efficiency,the area under the curve of ROC was 0.75,and the sensitivity was 73.7％,specificity was 76.5 ％,positive predictive value was 93.3 ％,negative predictive value was 39.4％,accuracy was 74.2％.Conclusions △size％ changes in consistent with △THC％ among the intergroups,but their changes levels are different,the highest change percent appears in CR,gradually decreased in PR,SD groups.△THC％ will contribute to predict preoperative clinical NAC efficacy.

Objective: To evaluate the effectiveness of a comprehensive intervention for childhood obesity on self-efficacy, weight perception, and stage of behavior change, and to provide a scientific evidence for childhood obesity interventions. Methods: The study was a cluster randomized controlled trial. Twelve primary schools and 1 889 children (aged 7-11 years) from Dongcheng District in Beijing were recruited in September, 2013, and were administered a comprehensive intervention for childhood obesity. Six schools (930) were randomly allocated to the intervention group, and six schools (959) were randomly allocated to the control group. A face-to-face questionnaire survey was carried out, R 4.0.3 software was used to analyze the data, and multiple linear regression model was used to analyze the intervention effect. Results: After the intervention, mean (standard deviation) scores of self-efficacy among children in the intervention and control groups were (4.4±0.9) and (4.2±1.1), respectively. After the intervention, the proportion of children in the intervention group who underestimated or overestimated their body weight was 28.4% and 11.3 %, respectively, while the figures in the control were 37.1% and 6.9%; compared with the control, the risk of underestimating body weight decreased among children in the intervention group( OR=0.64, 95%CI=0.52-0.80, P <0.01), while the risk of weight overestimation increased( OR=1.79, 95%CI=1.26-2.54, P <0.01). After the intervention, the proportion of children in the contemplation or action stage of behaviour change was 65.3% and 83.6%, while the figures in the control group were 59.8% and 69.8 %, respectively; in comparison with the control group, more children in the intervention group were in comtemplation ( OR= 1.28 , 95%CI=1.03-1.59, P =0.02) or action stage of behaviour change( OR=2.59, 95%CI=2.04-3.27, P <0.01). Conclusion The comprehensive intervention for childhood obesity improved self-efficacy, weight perception, and facilitated behavior change, but may increase the risk of weight overestimation.

Objective: To study the relationship between nutrition status and physical fitness in 8-10 year-old children in 3 cities, and to provide a scientific reference for improving physical condition of chidren of pre-school age. Methods: To investigate the weight, height and physical fitness (standing long jump, endurance running, rope skipping in one minute and sit-ups in one minute) of 1 384 children in grade four from 24 primary schools in Beijing, Changzhi, Urumchi in 2018. Evaluated overweight and obesity by using the standard of “Screening for Overweight and Obesity among School-age Children”. Then used mixed linear model to compare the physical fitness of students with different nutritional status and to analyze the relationship between BMI and physical fitness. Results: The prevalence of overweight and obesity were 17.41% and 23.48%, respectively. And the prevalence in boys was both more than that in girls(χ2=9.84，47.68，P<0.01). The increase in BMI of children from the same age and the same gender was related with the decrease in physical fitness by correlation analysis(P<0.05). In comparison method, the performance of the students of normal weight was better than obese students, but the male and female students had got the same results in their physical fitness test(P<0.05). Conclusion There is a negative correlation between nutrition status and physical fitness and the physical fitness in normal weight and obese children are better than the overweight children or obese children.

Objective: To observe the joint effect of school and family tobacco control on middle school students, and to explore its effectiveness in reducing second-hand smoke exposure in middle school students’ families, as so asto provide a new way of thinking for controlling smoking among middle school sudents. Methods: A questionnaire survey was conducted on the study of 2 125 primary and high school students in four middle schools in the Dongcheng District of Beijing by means of a stratified group sampling method. Personal information of students, tobacco control environment around the family, school and surrounding ares, as well as the knowledge, attitude and behavior of students related to tobacco control was collected. Results: The exposure rate of second-hand smoke in the families of middle and high school students in Dongcheng District of Beijing was 33.41%. Smoking by at least one parent was positively correlated with second-hand smoke exposure in the student’s home (OR=22.88, P<0.05). Among the students who saw the "clear no-smoking label" on campus, the exposure rate (4.92%) when the smoking restriction was set on the home was lower than that of those who did not have a regulation in the home (58.94%) (χ2=452.57, P<0.01). The results of Logistic regression showed that there was a combination of family smoking restrictions and second-hand smoke exposure in middle and high school students who had seen the smoking ban on campus (OR=0.08) and had the school’s tobacco control education (OR=0.08). Conclusion The joint tobacco control measures between school and family can effectively reduce the exposure rate of second-hand smoke in middle school students’ families, which is better than the effect of tobacco control alone.

Objective: To describe the baseline characteristics of School-based Cardiovascular and Bone Health Promotion Program(SCVBH) in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method. 15 391 students in grade 1 to 4 from primary schools, grade 1 from junior and senior high schools were enrolled in the investigation with an exclusion of students who were not able to participate due to trauma or other uncomfortable physical conditions. The baseline survey including a questionnaire survey, physical examination and blood biochemical test was conducted from September 2017 to January 2018. Obesity, blood pressure, fasting blood glucose, lipid, bone density and grip were evaluated. Results: The prevalence of obesity, hypertension, hyperglycemia (impaired fasting glucose and diabetes), dyslipidemia, lower bone density were 22.3%(3 394), 14.8%(2 248), 10.4%(1 490), 20.3%(2 919) and 2.1%(316) in total respectively, and 27.2%(2 081), 16.3%(1 244), 12.8%(922), 22.2%(1 595) and 1.2%(94) for boys, 17.3%(1 313), 13.3% (1 004), 7.9%(568), 18.4%(1 324) and 2.9%(229) for girls. Boys had higher prevalence of obesity, hypertension, hyperglycemia, and dyslipidemia and lower prevalence of low bone density than girls (all P values <0.05) The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05).The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05), the mean of fat mass percentage, total cholesterol, triglyceride, high density lipoprotein-cholesterol and low density lipoprotein-cholesterol of boys were significantly lower than those of girls (all P values <0.05). Conclusion The prevalence of risk factors of chronic cardiovascular disease was high and the low bone density was appearing in children and adolescents in this study. The promotion of cardiovascular and bone health should be implemented in children and adolescents.

Objective: To describe the status of cardiovascular health (CVH) of children and adolescents aged 6-16 years in Beijing during 2017-2018. Methods: The school-based Cardiovascular and Bone Health Promotion Program(SCVBH) was conducted from November 2017 to January 2018. 15 391 children and adolescents aged 6-16 years were selected from grade 1 to 4 in 8 primary schools, grade 1 in 21 middle schools and senior grade 1 in one twelve-year education school in Dongcheng, Fangshan, Miyun and Haidian Districts of Beijing by using a cluster sampling method. Seven cardiovascular health indicators, including smoking, body mass index, dietary intake, physical activity, blood pressure, blood glucose, and total cholesterol, were categorized as poor, intermediate, and ideal according to American Heart Association (AHA) criteria. The status of CVH was evaluated according to the criteria of the ideal CVH related behaviors and factors defined by AHA. Results: The proportion of children and adolescents with an ideal smoking, dietary intake and physical activity indicators reached 99.2%(4 982/15 108), 19.7%(2 921/14 805), 17.8% (2 499/14 056), respectively. The proportion of children and adolescents with 7 and 4-5 ideal cardiovascular health indicators was 1.7%(209/12 560) and 65.1%(8 176/12 560). The proportion of children and adolescents with 4-7 ideal cardiovascular health indicators, 2-4 ideal health behavior indicators and 2-3 ideal health factors was significantly higher in urban than that in rural all P values<0.001. The proportion of females with 4-7 ideal cardiovascular health indicators, 2-4 ideal health behavior indicators and 2-3 ideal health factors was significantly higher than that in males (all P values<0.001). Conclusion The prevalence of ideal cardiovascular health of children and adolescents aged 6-16 years in Beijing during 2017-2018 was very low, particularly for healthy dietary intake and physical activity. Effective public health interventions should be implemented to improve the status of cardiovascular health of them.