Objective: To investigate the association between bedtime screen use and sleep health among fourth and fifthgrade primary school students, so as to provide evidence to support interventions for improving sleep quality. Methods: From April to June 2024, a survey was conducted among 4 232 fourth and fifthgrade students from nine primary schools in a district of Beijing. A selfdesigned questionnaire assessed bedtime screen use behavior and sleep health indicators. Generalized linear models and Logistic regression were used to analyze the associations. Results: Among the surveyed students, 28.3% reported bedtime screen use. Mean sleep duration every day was (9.31±0.90) hours on school days and (10.08±1.36) hours on weekends. Compared to nonusers, students with bedtime screen use exhibited every day: later bedtimes on school days (10.18 min delay, 95%CI=6.88-13.47) and weekends (22.09 min delay, 95%CI=17.33-26.85) (P<0.05); later weekend wake times (7.97 min delay, 95%CI=1.78-14.16, P<0.05); reduced sleep duration on school days (-9.82 min, 95%CI=-13.62 to -6.03) and weekends (-14.12 min, 95%CI=-20.24 to -8.00) (P<0.05); greater weekend-school day bedtime discrepancy (β=1.15, 95%CI=1.08-1.23, P<0.01). Additionally, they had lower odds of falling asleep within 20 minutes (OR=0.62, 95%CI=0.54-0.72), daytime alertness (OR=0.66, 95%CI=0.56-0.77), and subjective sleep satisfaction (OR=0.57, 95%CI=0.49-0.66)(P<0.01). Conclusions Bedtime screen use is associated with adverse effects on multiple dimensions of sleep health in primary school students. Reducing screen exposure before bed may help improve their sleep quality.

Objective: To develop a health literacy evaluation scale for Chinese high school students, providing a tool for dynamic monitoring of health literacy among high school students and evaluating the effectiveness of health school construction. Methods: Through theoretical research, an evaluation index system for health literacy of Chinese high school students was constructed. Two rounds of Delphi expert consultations were conducted to quantitatively screen the items, and the item pool was revised based on expert opinions to compile the health literacy evaluation scale for Chinese students. Two focus group interviews were held to collect suggestions from health educators, high school teachers, and high school students regarding optimized scale length, question types, difficulty and wording of the scale. The scale was revised accordingly. A pilot survey was conducted in Beijing and Tianjin in November 2024, and the reliability and validity of the scale were evaluated based on the pilot survey data. Results: The response rate in both rounds of Delphi expert consultations was over 80%, and the expert authority coefficient was over 0.70. The expert opinions were highly concentrated, and the dispersion was small. The revised item pool based on expert opinions contained 39 items. The revised scale based on the suggestions and opinions collected from the focus group interviews had a moderate number of questions and difficulty level. The pilot survey obtained 800 valid responses, with the response rate of 89.39%. The Cronbach α coefficient of the scale was 0.911, χ 2/df =3.321, the root mean square error of approximation was 0.054, the adjusted goodness-of-fit index was 0.991 , and the factor loadings of some items were less than 0.40. Conclusion The health literacy evaluation scale for Chinese high school students demonstrates scientific rigor and practical applicability, with good internal consistency and structural validity.

Objective: To develop and validate a health literacy assessment scale for junior high school students, providing an effective tool for evaluating and monitoring health literacy among Chinese adolescents. Methods: Based on school health education policy documents, a health literacy assessment framework was constructed, comprising five horizontal and four vertical dimensions. From May to June and August to September in 2024, the framework was refined through Delphi expert consultations and focus group discussions, leading to the development of the Health Literacy Assessment Scale for Junior High School Students. In September 2024, a convenience sample of 625 students from three junior high schools in Beijing and Tianjin completed the questionnaire. Item analysis, reliability, and validity tests were conducted to evaluate the scale. Results: The recovery rate for two rounds of expert consultation questionnaires was 100%. The expert authority coefficients ( Cr ) were 0.86 and 0.87 respectively (both >0.70), with Kendall W values of 0.34 and 0.27 ( P <0.05). The focus group discussions followed a rigorous structure, and after multiple rounds of item screening and revision, the version 3.0 of the junior high school students health literacy assessment scale was developed, comprising 57 items. Three items that failed to meet the comprehensive screening criteria were preliminarily removed, and the final scale contained 54 items. The scale demonstrated excellent reliability, with an overall Cronbach s α coefficient of 0.92 and split half reliability of 0.93. Confirmatory factor analysis [ χ 2/df =2.094, root mean square error of approximation ( RMSEA )=0.042, comparative fit index ( CFI )=0.911, Tucker Lewis index ( TLI )=0.907] indicated good model fit indices. Conclusions The preliminary development of the health literacy assessment scale for junior high school students follows a rigorous item screening process with well designed dimensions, demonstrating good reliability and validity, thus serving as an appropriate evaluation tool for adolescent health literacy.

Objective:To detect itching,anxiety,depression behaviors in chronic itch models of mice and observe the activation of γ-aminobutiric acid(GABA)neurons in the ventral sector of the zona incerta(ZIv),and provide mor-phological evidence for their involvement in the modulation of itch information.Methods:Diphenylcyclopropenone(DCP)was used in glutamic acid decarboxylase 67-green fluorescent protein(GAD67-GFP)knock-in mice to establish chronic itch model.Itch behaviors were detected by video tracking system to verify whether the models were successfully established.The anxiety,depression behaviors of chronic itch model mice were detected by using elevated plus maze test(EPM)and tail suspention test(TST).By using GAD67-GFP mice,the distribution of GABAergic neurons in va-rious sectors of the zona incerta(ZI)was observed.And combined with immunofluorescence staining method,double labeling of GABAergic neurons with FOS in ZIv were observed respectively in control and DCP group mice.Results:In brain slices of GAD67-GFP mice,GABAergic neurons can be observed within all sectors of ZI and are more concentrat-ed in ZIv.Compared with control group mice,DCP group mice showed a significant increase in the bouts of scratching(P＜0.001).The time of immobility in TST was significantly higher in DCP group mice than in control group mice,which displayed depression-like behavior.The EPM test showed that the numbers of entries and proportion of time in the cross region in DCP group mice were less than in control group mice.EPM test revealed that DCP group mice exhibited anxiety-like behavior.The results of immunofluorescence staining showed that the number of FOS-positive cells in ZIv was significantly higher in DCP group mice than in control group mice,and abundant co-labeled neurons of FOS and GABAergic neurons were observed in ZIv.Conclusion:GABAergic neurons were predominantly distributed in ZI,and were more concentrated in ZIv.The activation of GABAergic neurons in ZIv of DCP group mice provides morphological evidence on the involvement of GABAergic neurons in chronic itch and associated negative emotions.

Objective: To understand the association of healthrelated quality of life of middle school students with parental companionship, so as to provide a reference for school and family health education. Methods: From September to November 2023, 4 594 middle school students were selected through convenient sampling from four economic zones in China (Liaoning Province, Beijing City, Sichuan Province, Shanxi Province). Structured questionnaires were used to evaluate healthrelated quality of life among middle school students. The ttest, variance analysis and linear regression were used to analyze the relationship between healthrelated quality of life with parental companionship among middle school students. Results: The average score of healthrelated quality of life among middle school students was (140.99±21.38). There were statistically significant differences in the scores of healthrelated quality life among middle school students in different regions, genders, educational stages, grades, whether they live on campus and parental companionship(F/t=20.73, 8.62,16.71,105.70, -9.51, 52.29, P<0.01). Linear regression analysis showed that students who were living in eastern region, boys, with higher selfevaluation of academic performance, with higher subjective family socioeconomic status, with parental companionship (β=3.19, 4.96, 2.19, 6.11, 3.19), and older students had lower healthrelated quality of life levels (β=-2.34)(P<0.01). Conclusions There are significant regional differences in the healthrelated quality of life levels among middle school students. It is necessary to strengthen the popularization of school health education and focus on students who do not live with their parents on a daily basis to provide more psychological support for them.

Objective: To analyze and evaluate the comprehensiveness and reliability of the content related to comprehensive sexuality education in 16 subject curriculum standards in the current compulsory education system, and the feasibility and effectiveness of comprehensive sexuality education teaching practice. Methods: Based on the textbook analysis model, a curriculum standard analysis model was established, and the interpretive structure model was used to analyze and evaluate the content related to comprehensive sexual education in the curriculum standards of 16 subjects in the current compulsory education system, including Ethics and Rule of Law, Chinese, History, Mathematics, English, Japanese, Russian, Geography, Science, Physics, Chemistry, Biology, Information Technology, Physical Education and Health, Arts, Labor. Results: There were 7 subject curriculum standards including Ethics and Rule of Law, Chinese, English, Science, Biology, Information Technology, Physical Education and Health reflecting 5 core concepts and 12 themes of comprehensive sexuality education, and the most frequent core concept was Violence and Staying Safe and the Human Body and Development,as well as the most frequent theme was "Puberty". History, Mathematics, Japanese, Russian, Geography, Physics, Chemistry, Art and Labor didn t include content related to comprehensive sexuality education. The content related to comprehensive sexuality education in the curriculum standard of compulsory education presented three characteristics:it was closely related to the subject content, partial content was consistent with the teaching goal of the subject, and the content depth increased with the growth of grade. The comprehensiveness and reliability of comprehensive sexual education in the current compulsory education curriculum standards of China needed to be improved. Conclusion The comprehensiveness, reliability, feasibility and effectiveness of teaching practice of comprehensive sexuality education in 16 subject curriculum standards in the current compulsory education stage need to be improved.

Objective The study aimed to explore the main forms of double minute chromosomes(DMs)in the cell cycle of colorectal cancer at different phases,and to clarify the replication and separation phases of DMs.Methods After using serum-free starvation to block the progression of cell cycle in colorectal cancer COLO 320DM cells,Calyculin-A was used to induce interphase cells to prepare karyotype samples through advanced chromatin condensation.COLO 320DM cells were treated with colchicine to ob-tain mitosis(M)phase cells for karyotype analysis.The karyotypes of cells at the early stage of DNA synthesis(G1 phase),the late stage of DNA synthesis(G2 phase),metaphase(M-mid),anaphase(M-late),and telophase(M-ter)of mitosis were observed and photographed under a regular optical microscope,and counted the number of DMs.Results DMs mainly existed in monotypic form at the G1 phase,M-late phase and M-ter phase of cells.In the G2 and M-mid phases of cells,DMs mainly existed in a diploid form.Conclusion Monomeric DMs undergo replication in the S phase and transform from monomers to diploids,while diploid DMs in the M-late phase complete separation and transition from diploids to monomers.

Objective: To preliminarily develop Health Literacy Scale for pupils, providing a tool for dynamic monitoring and related health literacy research among pupils. Methods: Through policy and literature review, the health literacy evaluation index system of pupils was established. Through two rounds of expert consultation, the evaluation index system and scale item pool of three levels in primary school were formed, and "Evaluation Scale 1.0" was developed. Through two panel discussions, health education experts, teachers and students were invited to provide advices on the content, expression and structure of scale 1.0, turning it into "Evaluation Scale 2.0", and completing the preliminary development of the scale. Results: The health literacy assessment index system of primary school students includes three levels，including level-1 was Grade 1-2, level-2 was Grade 3-4,level-3 was Grade 5-6, covering two level indexes. The scale for primary school students contained five horizontal dimensions and four vertical dimensions. In the Delphi consultation, the response rate was 100%, and the authority coefficient was 0.85. After item selection and modification, the final version of level-1, level-2 and level-3 scales contained 36, 44 and 50 items respectively. Conclusion The development of Health Literacy Evaluation Scale for pupils has high applicability and practical value.

Organic acids are organic compounds that can be synthesized using biological systems. They often contain one or more low molecular weight acidic groups, such as carboxyl group and sulphonic group. Organic acids are widely used in food, agriculture, medicine, bio-based materials industry and other fields. Yeast has unique advantages of biosafety, strong stress resistance, wide substrate spectrum, convenient genetic transformation, and mature large-scale culture technology. Therefore, it is appealing to produce organic acids by yeast. However, challenges such as low concentration, many by-products and low fermentation efficiency still exist. With the development of yeast metabolic engineering and synthetic biology technology, rapid progress has been made in this field recently. Here we summarize the progress of biosynthesis of 11 organic acids by yeast. These organic acids include bulk carboxylic acids and high-value organic acids that can be produced naturally or heterologously. Finally, future prospects in this field were proposed.
Saccharomyces cerevisiae/metabolism* ; Organic Chemicals ; Carboxylic Acids/metabolism* ; Metabolic Engineering ; Fermentation ; Acids

Objective:To evaluate the association between arterial lactate levels and complications within 30 days postoperatively in elderly patients undergoing pancreaticoduodenectomy.Methods:Elderly patients undergoing pancreaticoduodenectomy under selective general anesthesia in Beijing Hospital from July 2019 to December 2021 were enrolled.According to whether complications occurred within 30 days after operation, the patients were divided into complication group(C Group)and no complication group(N Group). General clinical data and lactic acid level before and after surgery were compared between the two groups.And the association between lactic acid level and complications within 30 days postoperatively was evaluated.Results:A total of 70 elderly patients were included in this study, of whom 22 patients had complications with proportion of 31.4%(22/70), including 2 cases of hemorrhage(2.9%, 2/70), one case of infection(1.4%, 1/70), 1 case of pneumonedema(1.4%, 1/70), 13 cases of pancreatic fistula(18.6%, 13/70), 5 cases of all-cause death postoperatively(7.1%, 5/70). There was no significant difference in baseline of arterial lactate level between two groups[0.70(0.50, 0.80)mmol/L vs.0.70(0.50, 1.20)mmol/L, Z=-1.150, P=0.250], while the lactate level at the end of the surgery was significantly higher in group C[1.60(0.90, 2.25)mmol/L]than in group N[1.00(0.80, 1.38)mmol/L]( Z=-2.396, P=0.017). The arterial lactate level at the end of the surgery was a risk factor for postoperative complications by multivariate analyses( OR=2.501, 95% CI: 1.154~5.418, P=0.020). Conclusions:Lactate level at the end of the surgery is related to early postoperative complications(within 30 days postoperatively)in elderly patients undergoing pancreaticoduodenectomy.Paying great attention to lactate monitoring at the end of the surgery may reduce the occurrence of perioperative complications in elderly patients undergoing pancreaticoduodenectomy.