Objective To investigate the longitudinal relationship between sleep duration(SD)and positive youth development(PYD)among primary and secondary school students in Chengdu city using a cross-lagged model,and to provide scientific evidence for enhancing sleep management practices for students.Methods A total of 4061 students of grades 3 through 9 from the Chengdu Child Positive Development Cohort were included in this three-wave longitudinal study.There was a one-year interval between one survey and the following round of survey,and the time points for the baseline,12-month follow-up,and 24-month follow-up surveys were designated T0,T1,and T2.The PYD of the participants was assessed using the Chinese version of the Positive Youth Development Scale.The demographic data and the average daily SD over the past month were collected.Spearman correlation analysis was performed to examine the associations between SD and PYD,and a cross-lagged model was used to investigate the longitudinal relationship between them.Results The average daily SD for the 3 rounds of surveys conducted at T0,T1,and T2 was 9.00(8.04,10.00)hours,10.44(9.67,11.11)hours,and 10.39(9.83,11.00)hours,respectively,while the PYD scores were 5.30(4.73,5.71),5.27(4.73,5.73),and 5.39(4.89,5.77),respectively.Statistical significance was found in the differences of SD and PYD scores across the 3 rounds(P＜0.05).Spearman correlation analysis revealed synchronous correlations between SD and PYD at all three time points(r=0.10 at T0,r=0.18 at T1,and r=0.21 at T2,P＜0.05)and significant lagged correlations(e.g.,r=0.10 for T1-PYD and T2-SD,and likewise,significant correlation was found for the 3 other cross-lagged paths).The cross-lagged model demonstrated that PYD at T0 and T1 positively predicted SD at T1 and T2,respectively(β0-1=0.116[95％CI,0.083-0.150],β1-2=0.097(95％CI,0.067-0.127),P＜0.05),and that SD at T0 and T1 also positively predicted PYD at T1 and T2(β0-1=0.028[95％CI,0-0.056],β1-2=0.042[95％CI,0.010-0.074],P＜0.05).According to these findings,a bidirectional predictive relationship between SD and PYD across different time points was observed in primary and secondary school students.Furthermore,PYD demonstrated better performance for predicting SD than SD did for PYD.Subgroup analysis by sex confirmed the robustness of the predictive power of PYD for SD.Conclusion This study reveals a positive bidirectional predictive relationship between SD and PYD among primary and secondary school students,suggesting that higher levels of PYD may contribute to adequate sleep.These findings provide critical scientific evidence for schools and families to strengthen sleep management and promote the holistic development and well-being of adolescents.

Abstract Diabetic ketoacidosis (DKA) is a serious complication of diabetes in children. A small number of children with DKA can be complicated by cerebral edema, leading to acute brain dysfunction, which is the main cause of death in children with diabetes. Because of unclear pathogenesis and non-specific clinical manifestations, DKA complicated with brain edema is easy to be missed or misdiagnosed. The identification and management of risk factors of DKA complicated with brain edema and early identification of brain edema are of great importance for improving the prognosis. This article reviewed the literature about the pathogenesis, clinical manifestations, risk factors, treatment and prevention of DKA complicated with brain edema, so as to provide reference for its early clinical identification and intervention.

Objective To investigate the cost-effect of tele-wound treatment platform with cellular phone terminator and traditional outpatient treatment on chronic lower limb ulcers in remote district.Methods Thirty seven cases with chronic lower limb ulcers from the key hospitals in the district of west Hunan Province were collected by cluster sampling,and randomly divided into the intervention group (25 cases)and the control group (12 cases).They chose remote wound treatment platform intervention with cellular phone terminator and traditional dressing change in clinic.All patients received a 1.5-year follow-up,or cure and amputations were set as the endpoint of the study.The cost-effect,including the incidence of complications in the course of treatment,number of switches,treatment time,the cost of treatment,as well as medical human resources consumption was analyzed and compared between the two groups.Results The incidence of complications in the course of treatment in the intervention was (76.0％) significantly lower than the control group(91.7％).There was a significant increase in the dressing times and the duration of treatment; and there was no significant difference in the cost of treatment and medical human resources consumption between two groups.Conclusions Compared to the traditional outpatients wound treatment,the multimedia message-based tele-wound treatment platform unlikely increased medical human resources consumption and the cost of treatment,and may reduce the incidence of complications and the treatment time.