Objective To analyze the trend of changes in the ranges of body mass index(BMI)among students at a university in Tianjin from 2021 to 2024,and to propose intervention strategies based on the key influencing factors.Methods A total of 1 000 first-year students enrolled in 2021 at a university in Tianjin were randomly selected,and their physical fitness test data over the 4 years of undergraduate study were collected.Differences in physical fitness test results were compared among students with varying BMI ranges.Linear regression analysis was used to identify the key factors affecting changes in BMI ranges in the students.Results The proportion of underweight students remained relatively stable,decreasing slightly from 2.5%in the first year to 2.0%in the senior year.The proportion of students with normal weight showed a fluctuating downward trend,from 71.5%at college enrollment to 69.0%by the fourth year.In contrast,the proportion of overweight/obese students showed a fluctuating upward trend.In physical fitness tests for the first year,overweight/obese students showed the best performance in the standing long jump test([2.15±0.42]m,P=0.08),normal-weight students showed the best performance in the sit-and-reach test([20.1±7.5]cm,P=0.03),and underweight students performed best in the sit-up test(1 min[48.7±19.5]repeats,P=0.02).Simple linear regression analysis revealed that students who changed from being underweight to having normal weight by the senior year showed associations with sit-up performance(β=0.03,95%CI,0.018 to 0.041)and 1 000 m run(β=0.73,95%CI,0.601 to 0.877).Students who transitioned from having normal weight to being overweight/obese were showed negative associations with their performance in 800 m run(β=-0.08,95%CI,-0.102 to-0.047)and 1 000 m run(β=-16.9,95%CI,-19.110 to-13.826).Students who changed from being overweight/obese to having normal weight showed associations with their performance in standing long jump(β=-0.41,95%CI,-0.631 to-0.227)and 1 000 m run(β=-0.15,95%CI,-0.215 to-0.073).Conclusion Male students of different BMI ranges should focus on improving their 1 000 m run performance,and overweight/obese male students should emphasize standing long jump training as well.Underweight female students should strengthen sit-up training,normal-weight female students should focus on 800 m run training,and overweight/obese females students should strengthen standing long jump training.

Objective: To analyze the association of 24 h activity behaviors and physical health of primary school students, so as to provide a reference for promoting the physical health of children and adolescents. Methods: From May to June, 2023, by stratified random sampling method, 583 primary school students aged 7-12 were selected from Tianjin for physical health examination. ActiGraph GT3X+ was used to measure their 24 h activity behaviors for 7 d, and their mental health and 24 h activity behaviors were analyzed by gender and grade. LASSO regression was applied for assessing the impact of 24 h activity on their health. Results: The compliance rate of seated forward bending (93.12%) were higher in boys than girls (91.86%), and the differences were statistically significant ( χ 2=4.53, P <0.05). Sleep time ( β =0.06), light intensity physical activity (LPA) time ( β =0.11), and moderate to vigorous physical activity (MVPA) time ( β =0.14) were positively correlated with physical fitness, whereas sedentary behavior (SB) time ( β =-0.08) were negatively correlated with physical fitness, and MVPA time had a positive effect on physical health of children and adolescents, followed by LPA time; while sleep time also had a positive effect , and SB time had a negative effect ( P <0.05). Conclusions Primary school students are generally faced with low physical activity level and high SB time, and MVPA and LPA have a significant impact on physical health. Therefore, it is crucial to develop personalized and differentiated physical activity promotion policies and interventions for primary school students with different classmates and gender.

Objective To study the impact and mechanism of continuous venovenous hemofiltration (CVVH) in different uhrafihration rates on plasma cytokines in porcine endotoxemic shock. Methods Eighteen anesthetized mechanically ventilated pigs weighing 21-34 kg were randomly divided into three groups. In control group (n=6), the pigs received a 15.7 μg/kg endotoxin (E.coli 0111:84) infusion. In CVVH group (n=6) and high volume hemofihration (HVHF) group (n=6), the pigs received CVVH after the endotoxin infusion for 24 hours with an was taken before endotoxin infusion and at 0, 1, 6, 12, 24 h during CVVH. The plasma levels of TNF-α, IL-6, IL-10 and IL-18 were tested by ELISA. Results The survival time in control group was (15.4±5.2) h,CVVH group was (21.4±7.1) h,HVHF group was (22.4±6.7) h. The survival time in CVVH and HVHF group was significantly longer than that of control group (P< 0.05 ). Heart rate (HR), mean arterial blood pressure (MAP), central venous pressure (CVP) and cardiac output (CO) showed no significant differences among three groups. Plasma BUN and Ser increased gradually after the establishment of porcine endotoxemic shock model. BUN and Scr of CVVH and HVHF group were lower compared to control group (P<0.05), but there was no significant difference between CVVH and HVHF group (P>0.05). Plasma TNF-α and IL-6 peaked at T1, IL-10 peaked at TO, then they declined gradually. While IL-18 increased at TO and did not change after TO. A significant decrease of plasma IL-10 level was observed at T6, T12 and T24 in CVVH group compared with control group (P<0.05). HVHF group accomplished a greater decrease in plasma TNF-α (T6) and IL-10 (T6, T12, T24) levels compared with control group and CVVH group (P< 0.05). The levels of IL-6 and IL-18 showed no significant differences among three groups. There was a negative correlation between IL-6 and survival time (P<0.05). Conclusions HVHF and CVVH can prolong the survival time of porcine endotoxemic shock. IL-10 can be removed effectively with CVVH and HVHF. HVHF can also remove TNF-α effectively. CVVH and HVHF treatment can both remove BUN and Scr effectively. IL-6 is a powerful independent predictive factor for survival time of porcine endotoxemic shock.