[Objective]To evaluate the feasibility of the minic microgravity as a method and the layered cylindric collagen-chitosan-?-tricalcium phosphate composite as a scaffold for the cartilage tissue engineering after an observation of how it absorbs the chondrocytes and affects the cell behavior.[Method]The chondrocytes were isolated and multiplied in vitro,and then the chondrocytes were seeded onto the porous collagen-chitosan-?-tricalcium phosphate composite scaffold and were cultured in both minic microgravity and ordinary environment for 3 weeks.The effects of the composite scaffold on the cell adhesivity,proliferation,morphological changes and synthesis of the extracellularmatrix were observed by the growth curve,phase-contrast microscopy,histology,scanning electron microscopy and immunohistochemistry.[Result]The chondrocytes that adhered to the scaffold increased significantly and secreted extracellular matrix in the center of the porous scaffold around the chondrocytes under minic microgravity compared with ordinary environment.Immunohistochemistry of type Ⅱ collagen was positive.[Conclusion]The minic microgravity environment will be a good method for the cartilage tissue engineering.And the layered cylindric collagen-chitosan-?-tricalcium phosphate composite scaffold has a good cellular compatibility.It will be an ideal scaffold for the cartilage tissue engineering.

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: 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 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.

The rearrangement reaction of benzyl phenyl ethers (BPE) plays an important role in the organic chemistry and drug synthesis .This paper briefly reviewed the rearrangement reaction and its possible mechanism in various catalytic sys-tems ,such as trifluoroacetic acid ,phosphotungstic acid ,cyclodextrin ,molten tin and aluminium bromide .

Objective:To evaluate the therapeutic effect of electroacupuncture on acute gastrointestinal injury (AGI) in patients with severe traumatic brain injury (sTBI).Methods:A prospective randomized controlled trial was conducted. 126 consecutively hospitalized patients with AGI after sTBI admitted to intensive care unit (ICU) of the First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from January 2018 to December 2019 were enrolled. The patients were divided into observation group and control group by random number table. All the patients of two groups were given conventional treatment of western medicine for consecutive 7 days, including the treatments of primary diseases, indwelling nasogastric tube to extract gastric contents every 6 hours to determine gastric residual volume (GRV). When vital signs were basically stable, enteral nutrition (EN) was implemented and EN feeding amount and speed were adjusted according to GRV. On the basis of conventional western medicine treatment, the observation group was treated with electroacupuncture at Zusanli, Tianshu, Shangjuxu, Xiajuxu and Zhongwan, once in the morning and once in the evening, 30 minutes each time. The gastrointestinal function parameters including intra-abdominal pressure (IAP), serum diamine oxidase (DAO) and gastrointestinal failure (GIF) scores were observed before treatment and at day 3 and day 7 of treatment. The incidence of ICU hospital-acquired pneumonia (HAP-ICU), duration of mechanical ventilation (MV), length of ICU stay, 28-day mortality and adverse reactions of electroacupuncture were also observed in the two groups. Kaplan-Meier method was used for 28-day survival analysis.Results:During the 7-day treatment and observation, 26 cases of 126 patients withdrew from the study, and 100 cases were actually enrolled, 50 cases in the observation group and 50 cases in the control group. IAP and DAO at day 3 of treatment in both groups were significantly lower than those before treatment [control group: IAP (cmH 2O, 1 cmH 2O = 0.098 kPa) was 13.75±2.76 vs. 18.11±3.97, DAO (U/L) was 129.88±24.81 vs. 158.01±22.64; observation group: IAP (cmH 2O) was 13.56±2.19 vs. 18.50±3.54, DAO (U/L) was 129.11±29.32 vs. 159.36±28.65; all P < 0.01]. The gastrointestinal function parameters of the two groups improved gradually with the extension of treatment time, and the IAP, DAO and GIF scores at day 7 of treatment in the observation group were significantly lower than those in the control group [IAP (cmH 2O): 11.28±3.61 vs. 12.68±3.23, DAO (U/L): 49.69±17.56 vs. 57.27±20.15, GIF score: 2.02±0.74 vs. 2.40±0.70, all P < 0.05). The duration of MV and the length of ICU stay in the observation group were significantly shorter than those in the control group [duration of MV (days): 15.72±4.60 vs. 18.08±4.54, length of ICU stay (days): 16.76±4.68 vs. 19.26±5.42, both P < 0.05], and the incidence of ICU-HAP and 28-day mortality were significantly lowered (12.0% vs. 30.0%, 22.0% vs. 32.0%, both P < 0.05). Survival analysis showed that the 28-day cumulative survival rate in the observation group was significantly higher than that in the control group (86.4% vs. 76.1%; Log-Rank test: χ 2 = 37.954, P < 0.001). The patients in the observation group had no significant adverse reaction of electroacupuncture treatment. Conclusion:Electroacupuncture at corresponding acupoints can effectively improve gastrointestinal function in patients with AGI after sTBI, which is beneficial to shortening the length of ICU stay, promoting the recovery of the patients, and reducing the 28-day mortality.

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.

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 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.

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.