Objective: To investigate the prevalence and associated factors of depressive symptoms among junior and senior high school students in Beijing from 2019 to 2023, in order to provide a scientific basis for interventions targeting high risk groups. Methods: From 2019 to 2023, a stratified cluster random sampling method was used to select 88 927 junior and senior high school students from 16 districts in Beijing. The Center for Epidemiologic Studies Depression Scale(CES-D) was conducted to assess depressive symptoms. The Chi square test was used to compare the detection rates of depressive symptoms among different student groups, and the trend Chi square test was employed for trend analysis of detection rates across the years. Multivariate Logistic regression analysis was applied to examine the association between the detection of depressive symptoms and related factors among junior and senior high school students. Results: From 2019 to 2023, the prevalence rates of depressive symptoms among junior and senior high school students in Beijing were 20.45%, 18.19%, 16.64%, 17.89% and 18.17%, respectively, with an overall downward trend ( χ 2 trend =27.51, P <0.01). Multivariate Logistic regression analysis revealed that after adjusting for gender, monitoring year, educational stage,family structure,boarding status and has taken a medical leave of absence in the past year unhealthy dietary behaviors ( OR=1.80, 95%CI =1.73-1.87), physical inactivity ( OR=1.24, 95%CI =1.19-1.29), try smoking ( OR=1.46, 95%CI =1.35-1.58), try alcohol( OR=1.96, 95%CI =1.88-2.05), Internet addiction ( OR=3.88, 95%CI =3.57-4.22), and adverse ear related behavior ( OR=1.82, 95%CI =1.71-1.93) were all associated with an increased risk of depressive symptoms among junior and senior high school students (all P <0.05). Conclusions The prevalence depression symptoms among middle school students in Beijing showed a fluctuating downward trend from 2019 to 2023. Targeted interventions should be adopted to reduce the occurrence of depression symptoms among junior and senior high school students.

Objective: To understand the trends of classroom lighting and illumination of primary and secondary schools in Beijing from 2016 to 2023, so as to provide a scientific basis for targeted improvement measures. Methods: A sampling survey was conducted on the lighting and illumination indicators of 8 390 classrooms in primary and secondary schools in Beijing from 2016 to 2023. The survey included classroom daylight factor, window to floor area ratio, average illuminance and illuminance uniformity on the desks, average illuminance and illuminance uniformity on blackboards, as well as classroom lighting and blackboard illumination sources. Intergroup comparisons were performed using the Kruskal-Wallis H test and the Chi square test, and Spearman correlation analysis was used to examine the trend of classroom lighting and illumination changes. Results: Except the window to floor area ratio, the measured values and compliance rates of all lighting and illumination indicators showed an overall upward trend from 2016 to 2023 (daylight factor r = 0.27, χ 2 trend =206.80, average illuminance on the desk surface r =0.30, χ 2 trend =87.97, illuminance uniformity on the desk surface r =0.14, χ 2 trend =73.59, average illuminance on the blackboard r =0.33, χ 2 trend =477.43, illuminance uniformity on the blackboard r = 0.09, χ 2 trend =50.76) (all P ＜0.01). The lighting and illumination indicators of classrooms (included classroom daylight factor, average illuminance and illuminance uniformity on the desks, average illuminance and illuminance uniformity on blackboards) in urban schools, primary schools, and secondary schools from 2016 to 2023 showed an upward trend (urban r =0.23-0.40, χ 2 trend =88.66-392.18; primary school r =0.12-0.36, χ 2 trend =39.50-281.44; secondary schools r =0.06-0.31, χ 2 trend =11.79-213.73) (all P ＜ 0.01 ). The illuminance uniformity on the blackboard in suburban schools showed a downward trend ( r = -0.09, χ 2 trend =31.53, both P ＜0.01). The illuminance uniformity on the desk surface in suburban schools showed no significant change ( r =0.03, χ 2 trend =1.23, both P ＞0.05). The other indicators showed an upward trend (daylight factor r =0.28, χ 2 trend =40.69, average illuminance on the desk surface r =0.24, χ 2 trend =16.35, average illuminance on the blackboard r =0.25, χ 2 trend =118.05, all P ＜0.01). The trends of classroom and blackboard illumination sources were that fluorescent lamps decreased year by year and LED lamps increased by year (classroom illumination sources χ 2 trend =1 059.82, blackboard illumination sources χ 2 trend =1 070.25, both P ＜0.01). Conclusions The classroom lighting and illumination in primary and secondary schools in Beijing has shown an overall improving trend from 2016 to 2023. However, problems remain, such as limited improvement of illuminance uniformity indicators, late start and poor effect of reconstruction in suburban schools. Further improvements are still needed.

The C 2-C 7 sagittal vertical axis (SVA) is an essential biomechanical parameter for evaluating cervical spine alignment, and it is integral to the pathogenesis, progression, and prognosis of cervical spine disorders. This parameter is widely used in evaluating cervical sagittal balance and functional status. Internationally, a C 2-C 7 SVA of less than 25 mm is considered within the cervical range for sagittal balance, while values exceeding 40 mm indicate cervical sagittal imbalance or deformity. An increased C 2-C 7 SVA disrupts cervical spine biomechanics, leading to heightened static and dynamic loads on the cervical musculature. This, in turn, results in muscle fatigue and discomfort. In the short term, patients may experience axial neck symptoms, while a sustained elevation in SVA over time significantly raises the risk of cervical disc degeneration, radiculopathy, and myelopathy. Additionally, a higher C 2-C 7 SVA postoperatively places excessive stress on adjacent spinal segments, which can accelerate degeneration of intervertebral discs and facet joints, contributing to adjacent segment degeneration. Both short-term and long-term postoperative evaluations have shown that an increase in C 2-C 7 SVA is typically associated with poorer surgical outcomes, whereas effective control of SVA values is closely linked to better functional recovery. Therefore, in clinical practice, maintaining C 2-C 7 SVA within the normal range (<25 mm) is critical not only for optimizing treatment results but also for significantly reducing postoperative complications and improving overall patient quality of life.

Objective:To describe the prevalence of myopia and pre-myopia among preschool children aged 5-6 years in ten provinces or municipalities(hereinafter referred to as province)of China,and to provide a reference for the prevention and control of myopia,and the allocation of related health re-sources.Methods:Convenience sampling was used to select preschool children aged 5-6 years from 21 cities in 10 provinces(including 8 provinces and 2 municipalities)in China.Cycloplegic autorefraction was conducted.The distribution of myopia and pre-myopia was described using frequencies and percenta-ges.The Chi-square test was used to compare the differences in the prevalence of myopia and pre-myopia between regions with different varying economic development levels and between boys and girls,with a significance level of α=0.05.Results:A total of 12 926 preschool children aged 5-6 years were sur-veyed.The myopia prevalence was 5.5％,and the overall prevalence of myopia and pre-myopia was 43.4％.Boys had higher rates of myopia and overall prevalence of myopia and pre-myopia than girls(5.7％vs.5.2％,46.4％vs.40.1％),though the difference in myopia prevalence was not statistical-ly significant.Stratified analysis by the province,there was no statistically significant differences in the prevalence of myopia between boys and girls in any province(P＞0.05),but in 8 provinces,the preva-lence of myopia in boys was slightly higher than in girls.The overall prevalence of myopia and pre-myopia in boys was higher than in girls across all the 10 provinces,with 5 provinces showing statistically signifi-cant differences(P＜0.05).The investigated areas were divided into two categories,relatively more-developed areas and relatively less-developed areas,based on per capita gross domestic product(GDP).In 6 provinces,there was no statistically significant difference in the prevalence of myopia between the two categories of areas.In 2 provinces,the prevalence was higher in relatively more-developed areas,and in 2 provinces,it was higher in relatively less-developed areas.In 4 provinces,there was no statisti-cally significant difference in the overall prevalence of myopia and pre-myopia between the two categories of areas with relatively more-developed and relatively less-developed areas.In 3 provinces,the preva-lence was higher in relatively more-developed areas,and in 3 provinces,it was higher in relatively less-developed areas.Conclusion:The prevalence of myopia and pre-myopia among preschool children aged 5-6 years is relatively high.Boys show higher overall prevalence of myopia and pre-myopia than girls,but there is no significant difference in the prevalence of myopia.There is no consistent association be-tween the level of economic development and the incidence of myopia and pre-myopia in each province.

Aim To investigate the pharmacological mechanism of Ebselenin(Ebselen,EbSe)in the treat-ment of Escherichia coli(E.coli)infection,which had no significant inhibitory effect on Gram-negative bacte-ria,based on previous studies.Methods After EbSe intervention in E.coli infected Raw264.7 cells,the via-bility of Raw264.7 cells was determined by CCK-8 method,the morphology and structure of Raw264.7 cells were observed by electron microscope,and the in-tracellular bacterial load of Raw264.7 cells was calcu-lated by coated plate method.Polarization status of peritoneal macrophages,Raw264.7 intracellular NO and ROS content and intracellular HO-1 expression in Raw264.7 and E.coli acutely infected mice after E.co-li infection by flow cytometry.qPCR was used to detect the expression of related mRNAs in Raw264.7 cells.qPCR was used to detect the intracellular GSH content in Raw264.7 cells by spectrophotometric assay,and the state of cytoskeletal proteins was observed by immuno-fluorescence.Western blot assay was performed to de-tect the intracellular Txnrd1 expression level.Results Microtiter method,CCK-8,and electron microscopy observations showed that EbSe had no effect on the growth of E.coli and Raw264.7 cells in vitro.The re-sults of smear plate counting showed that EbSe reduced the intracellular bacterial load of Raw264.7 in the in-fected group.Flow cytometry results showed that EbSe upregulated the number of M2-type macrophages.The EbSe-treated infected group had reduced intracellular NO and ROS levels and increased GSH levels.The qPCR results showed that the expression of IL-6,IL-1β,and iNOS was decreased,and the expression of HO-1,Txnrd1,and Glut1 was increased in DHB4-in-fected Raw264.7 cells after EbSe treatment.Cytoskel-etal staining showed that the morphology of the EbSe-treated infected cells was similar to that of oxPAPC-in-duced cells.Western blot results showed the expres-sion of Txnrd1 protein in EbSe-treated infected cells in-creased.Conclusion EbSe exerts anti-E.coli acute infection effect by regulating macrophage polarization and inhibiting macrophage excessive inflammatory state.

BACKGROUND:The biomechanical stability of basal femoral neck fracture is poor,and the treatment plan is different from the traditional femoral neck fracture. At present,there is still no consensus on the surgical plan for the treatment of basal femoral neck fracture in young adults. OBJECTIVE:To compare the biomechanical characteristics of proximal femoral nail antirotation and femoral neck system in the treatment of basal femoral neck fractures by finite element analysis.METHODS:First,Mimics Medical 21.0 software was used to extract the right femur CT data of healthy young female volunteers to establish a preliminary model. Secondly,the model was imported into Geomagic Wrap 2021 software for further smoothing. SOLIDWORKS 2021 software was used to establish and assemble the femoral neck base fracture model,proximal femoral nail antirotation model,and femoral neck system model. Finally,the assembled model was imported into Workbench 2021 R1 software for biomechanical analysis.RESULTS AND CONCLUSION:(1) Stress distribution:the stress distribution of the proximal femoral nail antirotation group was mainly near the fracture line and the medial side of the femur,and the peak stress was 151.90 Mpa. In the femoral neck system group,the stress distribution of the femoral model was mainly near the fracture line,and the peak stress was 290.74 Mpa. The proximal femoral nail antirotation internal fixation stress was mainly distributed at the proximal end of the helical blade and the main nail,and the peak stress was 102.95 Mpa. The stress distribution of internal fixation in femoral neck system mainly extended to both sides of the support rod,and the peak stress was 184.69 Mpa. (2) Total displacement:the maximum displacement of the femoral model in the proximal femoral nail antirotation group was 4.0323 mm,and the maximum displacement of the femoral model in the femoral neck system group was 4.6489 mm. The maximum displacement was located in the femoral head. The peak displacement of internal fixation in the proximal femoral nail antirotation group and the femoral neck system group was 2.7094 mm and 3.1303 mm,respectively. The displacement of internal fixation in the two groups was mainly concentrated in the proximal end of internal fixation,and gradually decreased to the distal end. (3) It is concluded that in the femoral neck base fracture model,whether it is the femoral model or the internal fixation model,the proximal femoral nail antirotation group has more dispersed stress distribution,lower stress peak,smaller femoral head displacement,and better biomechanical stability than the femoral neck system group.

BACKGROUND:The treatment of Pauwels type Ⅲ femoral neck fractures in young adults is extremely difficult.When treating Pauwels type Ⅲ femoral neck fractures with internal fixation,it is not only necessary to ensure the mechanical stability of the internal fixation,but also to ensure that it can resist the impact of shear,compression and tension,so as to prevent the internal fixation from breaking or loosening due to fatigue during the fracture healing process.However,existing internal fixation methods do not fully meet our requirements for the treatment of this fracture.OBJECTIVE:To provide a more reasonable and effective choice of internal fixation mode for clinicians in the treatment of young adults with Pauwels type Ⅲfemoral neck fracture,so as to optimize the treatment effect,reduce the occurrence of complications,and improve the recovery speed and quality of life of patients.METHODS:A femoral neck fracture model with Pauwels angle of 70° was constructed using CT data extracted from volunteers,and three placement modes were set up:(1)femoral neck system group:the main nail of femoral neck system was located in the center of the femoral neck axis.(2)Combination group:The main nail of femoral neck system was located in the lower third of the femoral neck axis,and a cannulated compression screw was located in the upper third of the femoral neck axis.(3)Cannulated compression screw group:The arrangement of three cannulated compression screws was arranged in the classic inverted triangle shape to ensure the maximum fixed effect.Stress distribution and displacement of proximal femoral fracture fragments and internal fixation devices were analyzed under three different internal fixation methods.RESULTS AND CONCLUSION:(1)The stress of the proximal femur models in the three groups was concentrated near the fracture line:combination group(201.10 MPa)＜femoral neck system group(222.25 MPa)＜cannulated compression screw group(271.25 MPa).(2)The peak value of proximal femur displacement was located at the top:combination group(6.33 mm)＜femoral neck system group(9.37 mm)＜cannulated compression screw group(9.92 mm).(3)The internal fixation stress was concentrated on the screw surface at the broken end of the fracture and gradually extended from there to both sides;cannulated compression screw group(136.67 MPa)＜combination group(201.10 MPa)＜femoral neck system group(222.25 MPa).(4)The maximum displacement of the internal fixation device model was located at the very top of the internal fixation.The three groups gradually decreased from the top to the far end.The peak displacement values of combination group(6.21 mm)＜femoral neck system group(9.19 mm)＜cannulated compression screw group(9.51 mm).(5)The stress of proximal bone mass in the three models was mainly concentrated in the fracture end,especially in the lower part of the fracture end.This indicates that these regions were subjected to greater stress and strain during mechanical transfer;combination group(24.96 MPa)＜femoral neck system group(39.69 MPa)＜cannulated compression screw group(44.47 MPa).(6)The results indicate that the internal fixation strategy of femoral neck system combined with cannulated compression screw arranged in parallel coronal surface shows higher biomechanical stability than single femoral neck system fixation or cannulated compression screw in inverted triangle arrangement fixation,and provides a more reliable and effective solution for the treatment of Pauwels type Ⅲ femoral neck fracture in young adults.

Objective:To investigate the association of the interaction and combined effect of renal function and body mass index (BMI) with the risk for all-cause death in patients with type 2 diabetes mellitus (T2DM) in communities of Jiangsu Province.Methods:The study subjects were from the Comprehensive Research Project of Diabetes Prevention and Control conducted in Jiangsu from December 2013 to January 2014, and follow up was conducted for them until September 30, 2023. A total of 20 025 subjects were included in the study. Cox proportional hazards regression model was used to analyze the association of renal function with risk for death in T2DM patients, and the association of interaction between renal function and BMI and their combined effect with all-cause death risk in T2DM patients.Results:In the follow up for 198 370 person-years, a total of 4 459 deaths were recorded. Cox proportional hazards regression model analysis showed that renal dysfunction was associated with 71% risk of all-cause mortality in all T2DM patients [hazard ratio ( HR) =1.71, 95% CI: 1.59-1.84], as well as in all BMI subgroups. Likelihood ratio test indicated an interaction between renal function and BMI (interaction for P=0.030). Compared with patients with normal renal function and normal BMI, those with normal renal function and over weight or obesity had a lower risk of all-cause mortality, and those with renal dysfunction and low weight had the highest risk for death ( HR=2.78, 95% CI: 1.87-4.14). Conclusions:There is association of interaction between renal function and BMI with all-cause mortality in T2DM patients. T2DM patients with renal dysfunction and low body weight had significant higher risk for death.

The C 2-C 7 sagittal vertical axis (SVA) is an essential biomechanical parameter for evaluating cervical spine alignment, and it is integral to the pathogenesis, progression, and prognosis of cervical spine disorders. This parameter is widely used in evaluating cervical sagittal balance and functional status. Internationally, a C 2-C 7 SVA of less than 25 mm is considered within the cervical range for sagittal balance, while values exceeding 40 mm indicate cervical sagittal imbalance or deformity. An increased C 2-C 7 SVA disrupts cervical spine biomechanics, leading to heightened static and dynamic loads on the cervical musculature. This, in turn, results in muscle fatigue and discomfort. In the short term, patients may experience axial neck symptoms, while a sustained elevation in SVA over time significantly raises the risk of cervical disc degeneration, radiculopathy, and myelopathy. Additionally, a higher C 2-C 7 SVA postoperatively places excessive stress on adjacent spinal segments, which can accelerate degeneration of intervertebral discs and facet joints, contributing to adjacent segment degeneration. Both short-term and long-term postoperative evaluations have shown that an increase in C 2-C 7 SVA is typically associated with poorer surgical outcomes, whereas effective control of SVA values is closely linked to better functional recovery. Therefore, in clinical practice, maintaining C 2-C 7 SVA within the normal range (<25 mm) is critical not only for optimizing treatment results but also for significantly reducing postoperative complications and improving overall patient quality of life.

BACKGROUND:The biomechanical stability of basal femoral neck fracture is poor,and the treatment plan is different from the traditional femoral neck fracture. At present,there is still no consensus on the surgical plan for the treatment of basal femoral neck fracture in young adults. OBJECTIVE:To compare the biomechanical characteristics of proximal femoral nail antirotation and femoral neck system in the treatment of basal femoral neck fractures by finite element analysis.METHODS:First,Mimics Medical 21.0 software was used to extract the right femur CT data of healthy young female volunteers to establish a preliminary model. Secondly,the model was imported into Geomagic Wrap 2021 software for further smoothing. SOLIDWORKS 2021 software was used to establish and assemble the femoral neck base fracture model,proximal femoral nail antirotation model,and femoral neck system model. Finally,the assembled model was imported into Workbench 2021 R1 software for biomechanical analysis.RESULTS AND CONCLUSION:(1) Stress distribution:the stress distribution of the proximal femoral nail antirotation group was mainly near the fracture line and the medial side of the femur,and the peak stress was 151.90 Mpa. In the femoral neck system group,the stress distribution of the femoral model was mainly near the fracture line,and the peak stress was 290.74 Mpa. The proximal femoral nail antirotation internal fixation stress was mainly distributed at the proximal end of the helical blade and the main nail,and the peak stress was 102.95 Mpa. The stress distribution of internal fixation in femoral neck system mainly extended to both sides of the support rod,and the peak stress was 184.69 Mpa. (2) Total displacement:the maximum displacement of the femoral model in the proximal femoral nail antirotation group was 4.0323 mm,and the maximum displacement of the femoral model in the femoral neck system group was 4.6489 mm. The maximum displacement was located in the femoral head. The peak displacement of internal fixation in the proximal femoral nail antirotation group and the femoral neck system group was 2.7094 mm and 3.1303 mm,respectively. The displacement of internal fixation in the two groups was mainly concentrated in the proximal end of internal fixation,and gradually decreased to the distal end. (3) It is concluded that in the femoral neck base fracture model,whether it is the femoral model or the internal fixation model,the proximal femoral nail antirotation group has more dispersed stress distribution,lower stress peak,smaller femoral head displacement,and better biomechanical stability than the femoral neck system group.