Objective To investigate the setup error in patients with spinal bone metastasis who underwent radiotherapy under the guidance of kilovoltage cone-beam CT (KV-CBCT). Methods A total of 118 patients with spinal metastasis who underwent radiotherapy, including 17 cases of cervical spine, 62 cases of thoracic spine, and 39 cases of lumbar spine, were collected. KV-CBCT scans were performed using the linear accelerators from Elekta and Varian’s EDGE system. CBCT images were registered with reference CT images in the bone window mode. A total of 973 data were collected, and 3D linear errors were recorded. Results The patients with spinal bone metastasis were grouped by site, height, weight, and BMI. The P value of the patients grouped only by site was P<0.05, which was statistically significant. Conclusion When grouped by site in the 3D direction, the positioning effect of cervical spine is better than that of thoracic and lumbar spine. The positioning effect of the thoracic spine is better in the head and foot direction but worse in the left and right direction compared with that of the lumbar spine. Instead of extending or narrowing the margin according to the BMI of patients with spinal metastasis, the margin must be changed according to the site of spinal bone metastasis.

【Objective】 To investigate the development of adaptability in children aged 2 - 6, and to explore its influencing factors, so as to provide reference for promoting the development of adaptability in young children. 【Methods】 Data were from the National Nutrition and Health Systematic Survey for Children in China, and 3 319 children aged 2 - 6 and their parents from 28 sites across 14 provinces were recruited in this study.The Development Scale for Children Aged 0 - 6 years (WS/T 580-2017) was used to measure the developmental quotient of children′s adaptive ability, and a survey questionnaire was used to collect relevant information about children and their parents. 【Results】 Among 3 319 children aged 2 - 6, the proportion of slightly low or low level of adaptability, moderate adaptability development, good and excellent adaptability development was 7.68%,66.25% and 26.06%, respectively.The proportion of children aged 5 - 6 with good and excellent adaptability was lower in 3-year-old and 4-year-old groups (χ²=59.29, P<0.05).Multiple stepwise linear regression showed that children′s gender (β=0.06), gestational age of birth (β=-0.05), only child (β=-0.04), left-behind child (β=-0.04), the main caregiver (β=-0.06), and the education level of parents (β=0.09, 0.10), whether parents actively pay attention to children′s emotions (β=-0.06) and whether children play with homemade toys (β=-0.04) were the influencing factors of children′s adaptive development quotient.Girls, full-term children, only children, non-left-behind children, children with parents as main caregivers, parents with a high level of education, parents who often take the initiative to pay attention to children′s emotions, and children who play with homemade toys had a higher level of adaptability development quotient. 【Conclusions】 The development level of adaptability in children aged 2 - 6 in China is mostly above the average level and is related to multiple factors.Targeted intervention work can be carried out on relevant factors in order to promote the development of children′s adaptability.

Objective:To describe the distribution of fat-free mass (FFM) and fat-free mass index (FFMI) in children aged 3-17 years in China.Methods:Data were collected from National Nutrition and Health Systematic Survey in 0-18 years old children in China. By using multi-stage stratified randomized cluster sampling method, the project was conducted in 28 survey points in urban and rural areas in 14 provinces (autonomous regions and municipalities) in 7 regions in China from 2019 to 2021. FFM was measured using bioelectrical impedance meter. Finally, the body composition data of 70 853 children were included in the analysis. M ( Q1, Q3) was used to describe the gender and age specific FFM and FFMI of the children in different regions. Kruskal-Wallis H rank sum test was used to compare FFM and FFMI of boys and girls in same age group, boys in different age groups, girls in different age groups, as well as boys in same age group and girls in same age group in different regions. DSCF method was used for pairwise comparisons. Results:After the age of 11 years, the difference of FFMI between boys and girls increased year by year. The FFMI was 14.2 kg/m 2 in boys and 13.8 kg/m 2 in girls at 11 years old, the difference was significant ( χ2=135.86, P<0.001). The difference of FFMI between boys and girls exceed 1.0 kg/m 2 from 12 years old, and FFMI was 15.3 kg/m 2 in boys and 14.2 kg/m 2 in girls at 12 year old, the difference was significant ( χ2=597.27, P<0.001). The FFMI was 17.5 kg/m 2 in boys and 14.7 kg/m 2 in girls at 16 years old, the difference was significant ( χ2=2 543.60, P<0.001). The FFMI was higher in boys in northeast China, while the FFMI was lower in both boys and girls in northwest China. Conclusions:Gender specific difference was observed in the increase of FFMI with age. The FFMI was significantly higher in boys than in girls after 11 years old. It is necessary to pay attention to the problem of FFM in children in northeastern and northwestern China.

Objective:To investigate the distribution characteristics of body height, body weight and body mass index (BMI) in children aged 3-17 years in China.Methods:Data were obtained from the National Nutrition and Health Systematic Survey in 0-18 years old children in China. The study selected 70 853 children aged 3-17 years from 28 urban and rural survey sites in 14 provinces (autonomous regions and municipalities) in 7 regions of China with multi-stage stratified cluster random sampling. M ( Q1, Q3) was used to describe the region, age and gender specific body height, body weight and BMI in the children aged 3-17 years. Wilcoxon rank sum test was used to compare the body height, body weight, and BMI between boys and girls in same age group. Kruskal-Wallis H rank sum test was used to compare the body height, body weight and BMI among boys in different age groups and among girls in different age groups, as well as among boys in same age group and among girls in same age group from different regions, and DSCF method was used for further pairwise comparisons. Results:In this study, the median body height and body weight were 172.0 cm and 62.9 kg in 17-year-old boys and 160.0 cm and 53.7 kg in 17-year-old girls. The median for children's body height, body weight, and BMI in most age groups were higher in northeastern and northern China than in southern China, and the differences could be observed until age 17 years. The differences in body weight and BMI in children in northeastern and northern China were greater in Q3 than in Q1 compared with southern China. Conclusions:The body height of children aged 3-17 years continues to increase in China. Northeastern and northern China have more children with higher bodyweight, showing an obvious body weight increase trend, to which close attention needs to be paid.

Objective:To describe the distribution of fat mass (FM), fat mass percentage (FMP), and fat mass index (FMI) in children aged 3-17 years in China.Methods:Data of this study were from the National Nutrition and Health Systematic Survey in 0-18 years old children in China. A total of 70 853 children aged 3-17 years old selected from seven regions of China were included in this analysis. Body composition were measured by using bioelectrical impedance meter. The region, gender and age specific FM, FMP and FMI of the subjects were described by using M ( Q1, Q3). Kruskal-Wallis H rank sum test was used for the comparison of intergroup differences. DSCF method was used for pairwise comparisons. Results:The medians of FM, FMP and FMI were 3.0 kg, 18.3% and 2.9 kg/m 2 in boys aged 3 years and 2.9 kg, 19.0% and 2.9 kg/m 2 in girls aged 3 years, respectively. The FM increased with age and the FMP and FMI decreased with age in both boys and girls aged 3-5 years. After 11 years old, the FM, FMP and FMI decreased first and then increased in boys. From 6-17 years old, the FM, FMP and FMI increased gradually in girls. The FM, FMP and FMI were higher in girls than in boys after 12 years old (all P<0.05). The FM, FMP and FMI were relatively higher in children at the age of 6-14 in northeastern and northern China than in other regions. Conclusions:The age specific FM, FMP and FMI had different changing characteristics in boys and girls aged 3-17 years in seven regions of China. The FM, FMP and FMI also differed with region.

Objective:To analyze the relationship between body mass index (BMI) and fat mass percentage (FMP) in children aged 3-17 years in China.Methods:The BMI and FMP data of children aged 3-17 years from the National Nutrition and Health Systematic Survey in 0-18 years old children in China was analyzed. BMI- Z score/BMI and FMP were used to classify the subjects, respectively. Spearman correlation was used to analyze the correlation between BMI and FMP. The consistency between BMI- Z score/BMI and FMP in classifying the subjects was measured using Kappa coefficient. Results:The FMP of malnutrition, normal and overweight/obesity in boys was higher in age group 10-13-year than in other age groups (all P<0.001). The FMP of all nutritional status in girls increased with age (all P<0.05). The BMI of boys in all the FMP levels increased with age (all P<0.05). When the FMP of girls was 25%- or ≥30%, BMI increased with age (all P<0.001). The relationship between BMI and FMP was strong ( r=0.705, P<0.001), with r of 0.618 in boys and 0.884 in girls. The consistency between BMI- Z score/BMI and FMP in classifying the subjects was found to be moderate (Kappa=0.574, P<0.001). Conclusions:There was a strong relationship between BMI and FMP. The consistency between BMI- Z score/BMI and FMP in classifying the subjects was moderate.

Objective:To evaluate the consistency between bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) in the measurement of body composition in children aged 6-17 years in China.Methods:Fat-free mass, fat mass and fat mass percentage were measured by both BIA and DXA in 1 161 children. t-test or Wilcoxon paired test was used to evaluate the different outcome of the two methods. The correlation and consistency between the methods were evaluated by Spearman correlation coefficients ( r) and Bland-Altman analysis. Results:Body compositions measured by BIA was positively correlated with those measured by DXA (fat mass r=0.95, fat-free mass r=0.98, fat mass percentage r=0.86, all P<0.05). Comparing with DXA, BIA underestimate children's fat mass [the mean difference is -3.15 kg, and the SD is 2.35 kg, 95% limits of agreement (LoA): -7.74-1.45 kg] and fat mass percentage (the mean difference is -8.45%, and the SD is 4.63%, 95% LoA: -17.53%-0.64%). Conclusions:Body compositions measured by BIA was highly positively correlated with those measured by DXA. BIA has certain application value in the measurement of body fat mass and fat-free mass of children aged 6-17 years.

Objective:Cardiac arrest (CA) represents a significant public health challenge, posing a substantial threat to individual health and survival. To enhance the survival rates of patients experiencing out-of-hospital cardiac arrest (OHCA), Baoan District in Shenzhen City has undertaken exploratory initiatives and practical interventions, yielding promising preliminary outcomes.Methods:1.Innovate emergency medical services by developing a "four-circle integration" system that connects to the hospital. This system encompasses the social emergency medical system, the out-of-hospital emergency medical system, the in-hospital emergency medical service system, and the intensive care treatment system. 2.Develop a comprehensive model for the construction of a social emergency medical training system, characterized by party leadership, government oversight, departmental coordination, professional guidance, technological support, and community involvement, termed the "Baonan Model." Additionally, establish evaluation criteria to assess the effectiveness of the social emergency medical training system in Baonan District; 3. Develop a cardiac arrest registration system and a social emergency medical training management system for Baonan District; 4. Enhance the proficiency in treatment techniques and the quality of cardiopulmonary resuscitation among emergency medical professionals; 5. Strengthen and advance the development of a "five-minute social rescue network" to address the critical "emergency window period." .Result:In Baonan District, 9.18% of the public is trained in emergency medical skills. The bystander CPR rate for OHCA is 26.11%, AED use is at 4.78%, the 30-day survival rate is 6.31%, and the discharge survival rate is 4.44%.Conclusion:The implementation of the aforementioned measures can substantially enhance the survival rate of patients experiencing OHCA at the time of discharge.

Objective:To design an improved lamina hook system and compare its biomechanical properties with traditional lamina hook system in fixation of lumbar spondylolysis.Methods:The thin layer CT data of the lumbosacral vertebrae of 20 healthy young male servicemen who underwent physical examination in the outpatient department of the 940th Hospital of Joint Logistics Support Force of PLA from January 2021 to August 2022 were collected. The age of the subjects was 20-30 years [(25.0±3.0)years]. A 3-dimensional model of the L 5 vertebral body was constructed using the 3-dimensional modeling software. The new improved lamina hook was designed according to the measurements including the thickness of the middle area, the longest longitudinal diameter, the curvature radius of the lower edge, the angle between the upper and lower tail ends, the thickness of the lower edge, and the longest diameter of the lower edge of the bilateral L 5 vertebral plates. One serviceman was selected from the aforementioned group to construct a linear finite element model of segments L 4-S using the 3-dimensional virtual software (normal model, model A), based on which, the L 5 bilateral spondylolysis model (model B), improved lamina hook model (model C) and traditional lamina hook models (model D) were designed. By constraining both sides of the sacrum and applying a longitudinal load of 400 N on the L 4 vertebral body, the upper 1/3 gravity of the body was simulated, and with a bending moment of 10 N·m along the X, Y, and Z directions, motions of forward flexion, backward extension, lateral bending, rotation, etc were simulated. The range of motion of segment L 4/5 and L 5/S 1 of model A was evaluated and compared with the findings of the previous researches to verify its effectiveness. The overall range of motion of models A, B, C, and D, the range of motion of segment L 4/5 and L 5/S 1, the maximum overall displacement, the maximum displacement and stress of the isthmus, the stress distribution and maximum stress of internal fixation of models C and D, and the stress distribution and maximum stress of the vertebral body of models C and D were compared. Results:(1) During forward flexion, backward extension, lateral bending and rotation, the range of motion of model A was 5.01°, 4.03°, 3.91° and 1.42° in segment L 4/5, and was 4.62°, 2.51°, 2.40° and 1.23° in segment L 5/S 1. (2) The overall range of motion, range of motion of segment L 4/5 and L 5/S 1 and maximum overall displacement of models A, C, and D were similar in axial compression, forward flexion, backward extension, left bending, and left rotation, while those of model B were significantly increased. (3) There was no significant difference in the maximum displacement of the isthmus of models A, C, and D under different motion modes, while the maximum displacement of model B in the isthmus was significantly larger than that of models A, C, and D, especially during rotation, increased by 295%, 277%, and 276% respectively. The maximum stress of the isthmus of model C was 0.938 MPa, 1.698 MPa, 0.410 MPa, 2.775 MPa, and 1.554 MPa respectively. The maximum stress in the isthmus of model D was 0.590 MPa, 1.297 MPa, 0.520 MPa, 3.088 MPa, and 2.072 MPa respectively. The maximum stress of the isthmus of models C and D was similar during axial compression and forward flexion, while the stress of the isthmus of model C was smaller than that of model D during backward extension, lateral bending, and rotation, decreased by 21.1%, 10.2%, and 25.0% respectively compared with model D. (4) The maximum stress of internal fixation in models C and D during forward flexion, backward extension, left bending, and left rotation was 135.220 MPa, 130.180 MPa, 200.940 MPa and 306.340 MPa respectively, and was 131.840 MPa, 112.280 MPa, 349.980 MPa and 370.140 MPa respectively. The maximum stress of internal fixation in the two models of internal fixation during forward flexion and backward extension was similar, while it was decreased by 42.6% and 17.2% in model C during left bending and left rotation, compared with model D. (5) The maximum stress of the vertebral body during forward flexion, backward extension, left bending, and left rotation was 79.787 MPa, 36.857 MPa, 37.943 MPa and 96.965 MPa respectively in model C, but was 80.104 MPa, 64.236 MPa, 196.010 MPa and 193.020 MPa respectively in model D. The maximum stress of models C and D was all distributed in the contact area with the internal fixation, and especially during backward extension, left bending, and left rotation, when it was reduced by 42.6%, 80.6%, and 49.8% of model C respectively, compared with that of model D. Conclusions:The improved laminar hook is more consistent with the Chinese anatomized structure of the lamina. Compared with the traditional lamina hook system, the improved lamina hook system can effectively reduce the displacement in all directions and range of motion of lumbar spondylolysis, therefor can significantly reduce the stress of internal fixation and vertebral body and has better biomechanical performance.

Objective:To survey the awareness status and its influencing factors among parents of preschool children.Methods:Data was collected from the National Nutrition and Health Systematic Survey for 0-18 Year Children in China. A total of 2 625 children aged 3-5 years and their parents living in northern and southern regions of China were randomly selected by multi-stage stratified cluster sampling. The physical measurements were performed for the children, including height and weight; and the body mass index (BMI) and age-for-BMI Z-score (BAZ) were calculated. The questionnaire survey was conducted for the parents, including the demographic characteristics of parents and their children, the perception of their child′s nutritional status (overweight/obesity, normal, wasting) etc. According to WHO standards, the nutritional status of the children was classified as wasting, normal and overweight/obesity. The awareness of parents on their children′s nutritional status was classified as underestimated, correct, overestimated and unclear. Parents′ inability to correctly judge children′s nutritional status was defined as cognitive bias, including underestimation bias and overestimation bias. Multivariate logistic regression model was used to analyze the influencing factors of parents′ underestimation or overestimation of children′s nutritional status.Results:Among 2 625 enrolled preschool children, there were 1 312 boys (50.0%) and 1 313 girls (50.0%); and 648 (24.7%), 944 (36.0%) and 1 033 (39.3%) children aged 3, 4 and 5 years, respectively. One parent (mother, farther or others) of each child was selected for survey, and most of them were mothers (1 998(76.1%)). The prevalence rate of overweight/obesity and wasting was 10.3% (270/2 625) and 1.4% (38/2 625), respectively; and 2 317 children (88.3%) were normal. Among all parents surveyed, 1 766 (67.3%) were correct about their children′s nutritional status (correct group), 612 (23.3%) underestimated their children′s nutritional status (underestimated group), 213 (8.1%) overestimated their children′s nutritional status (overestimated group) and 34 (1.3%) were not aware of their children′s nutritional status (unclear group). The multivariate logistic regression analysis showed that girls ( OR=0.817, 95% CI: 0.678-0.984), living in rural areas ( OR=0.801, 95% CI: 0.662-0.969), large birth weight of child ( OR=0.639, 95% CI: 0.420-0.970) were protective factors for parents underestimating children′s nutritional status. Living in the northern region ( OR=1.698, 95% CI: 1.260-2.290), large birth weight of children ( OR=1.826, 95% CI: 1.149-2.902), father with overweight/obesity ( OR=1.467, 95% CI: 1.089-1.977) and maternal overweight/obesity ( OR=1.778, 95% CI: 1.308-2.417) were the risk factors for parents to overestimate the nutritional status of children. Conclusions:The survey shows that parents of preschool children have a relatively high cognitive bias on the nutritional status of their children. Parents of girls, living in rural areas or having child with large birth weight are less likely to underestimate the nutritional status of children; parents living in northern regions, having a child with large birth weight, or with overweight/obese are likely to overestimate the nutritional status of children.