Objective: To determine 17 types of phthalic acid esters (PAEs) in drinking water using solid-phase extraction coupled with gas chromatography-mass spectrometry (GC-MS) in multiple reaction monitoring (MRM) mode. Methods: One litre of commercially available bottled water was purified using an HLB solid-phase extraction column, and was eluted with ethyl acetate, dichloromethane and average methanol. Seventeen types of PAEs were detected using a triple quadrupole gas chromatography-mass spectrometer in MRM mode. By optimizing the temperature programming and adjusting the mass spectrometry collision energy, collection efficiency was improved and matrix interference was reduced. The precision and accuracy of this method were assessed by determining the standard curves, detection limits, quantification limits, relative standard deviations (RSD) and average spiked recovery rates for the 17 types of PAEs. Results: The 17 types of PAEs showed good linear relationships between mass concentration and chromatographic peak areas in the range of 0.02 to 1.0 mg/L, with correlation coefficients all greater than 0.999 1. The detection limits ranged from 0.002 9 to 0.009 7 mg/kg, the quantification limits ranged from 0.008 7 to 0.029 1 mg/kg, the RSD ranged from 0.8% to 3.0%, and the average spiked recovery rates ranged from 88.8% to 111.8%. Conclusion Solid-phase extraction coupled with MRM of GC-MS can better determine low concentrations of PAEs in drinking water.

Objective: To explore the prevalence of screening myopia and depressive symptom among primary and secondary school students in Xuzhou, and to explore the association of sleep and screen time on the coexistence of screening myopia and depressive symptom, so as to provide scientific references for developing intervention strategies to address the development of myopia and promote mental health in children and adolescents. Methods: From September to October 2024, a stratified cluster random sampling method was used to select 6 605 students in grade 4 to 12 in 2 urban and 2 suburban districts in Xuzhou. The students health condition and influencing factors questionnaire were used to assess students basic information, sleep time, and screen time. The Center for Epidemiological Studies Depression Scale (CES-D) was used to assess primary and secondary school students depressive symptom.Unaided distance visual acuity examination was conducted, and refractive assessment was performed using an automated refractometer without cycloplegic agents. The Chi-square test and multiple Logistic regression analysis were used to evaluate the association of sleep and screen time with the coexistence of screening myopia and depressive symptom. Results: The detection rates of screening myopia, depressive symptom, and screening myopia and depressive symptoms co morbidity among primary and secondary school students in Xuzhou were 60.35%, 4.45% and 18.61% respectively. Results from the multinomial Logistic regression analysis, using the healthy group as the reference and after adjusting for confounding factors, showed that students with insufficient sleep duration were more likely to have depressive symptom ( OR=1.57, 95%CI =1.08-2.27) and the coexistence of screening myopia and depressive symptom ( OR=1.85, 95%CI =1.45-2.36). Students with daily screen time≥2 h were more likely to have depressive symptom only ( OR=1.41, 95%CI =1.04-1.93) and the coexistence of screening myopia and depressive symptom ( OR=1.31, 95%CI =1.06-1.61). Further stratified analysis based on sufficient and insufficient sleep duration revealed that only in the insufficient sleep duration group, students with daily screen time≥2 h had an increased risk of depressive symptom only ( OR=1.49, 95%CI =1.07-2.07) and the coexistence of screening positive myopia and depressive symptom ( OR=1.40, 95%CI =1.11- 1.77 ) (all P <0.05). Conclusions Primary and secondary school students with insufficient sleep duration and daily screen time≥2 h have higher risks of depressive symptoms and the coexistence of screening myopia and depressive symptoms. It is recommended to ensure adequate sleep duration and limit screen time for children and adolescents.

Different porous structures were studied through finite element analysis and then optimal porous structure was selected for the orthopedic applications.The optimal Voronoi structure was designed and fabricated using 3D printing.The mechanical properties and osseointegration ability were both investigated.The mechanical tests showed that the tensile strength,compressive strength and bending strength of Voronoi structures were obviously higher than that of the human bone,and the modulus of Voronoi structures were similar to human bone.In addition,the animal experimental results exhibited that obvious bone ingrowth was found from Month 1 to Month 6.This study provides some theoretical references for the orthopedic application of porous structures.