Abstract The study examines the development and application of microclimate standards for primary and secondary school classrooms, so as to ensure and promote the healthy growth of primary and secondary school students. The paper systematically reviews relevant domestic and international standards, analyzes the problems and shortcomings arising from their practical application and proposes effective countermeasures, in order to provide robust references aimed at optimizing the classroom environment in primary and secondary schools for student health, as well as offering practical support to advance the construction of a healthy China.

Objective: To understand the microclimate in primary and secondary school classrooms for the study period during the winter heating season, so as to provide a reference for the revision and improvement of relevant health standards. Methods: In December 2024, stratified random sampling was used to select 30 primary and secondary schools and 180 classrooms from the northern regions with centralized heating (Liaoning Province, Tianjin City) and the southern regions without centralized heating (Shanghai City, Anhui Province, and Jiangxi Province). Indoor temperature, relative humidity, wind speed, CO 2 and other indicators were measured on site. Variance analysis, t-test, Mann-Whitney U test and Kruskal-Wallis H test were used to analyze the differences in the microclimate of classrooms among regions and urban and rural differences. Results: The average temperature in the middle of the classrooms tested on site was (16.47±4.72)℃, and the variance analysis showed that the difference between the regions was statistically significant ( F=27.80, P <0.01). Among them, Tianjin had the highest average temperature of (20.43± 2.12 )℃, followed by Liaoning (19.03±2.23)℃, Shanghai (15.33±5.32)℃, Anhui (12.79±1.74)℃, and Jiangxi (11.69± 1.68 )℃. Horizontal temperature difference was 0.90 (0.50, 1.60)℃, the vertical temperature difference was 0.20 (0.10,0.60)℃, the average relative humidity was (44.39±16.16)%, the wind speed was 0.03(0.01,0.11)m/s, and the differences among different provinces and cities were statistically significant ( H/F =40.62, 82.69, 95.06, 55.28, all P <0.01). The average CO 2 volume concentration in urban areas of Tianjin, Liaoning, and Shanghai was 0.21(0.16,0.30)%, and there was no statistically significant difference ( H=4.65, P =0.10). There were grade differences in relative humidity ( F =3.71, 6.21) and CO 2 ( H =14.72, 12.92) in the north and the south (all P <0.05). In addition, the temperature, relative humidity, wind speed and CO 2 in the middle of the classroom were 42.8%, 67.8%, 100.0% and 22.2% respectively. Conclusions The temperature in the middle of the classroom in the non centralized heating area is lower than the standard, the relative humidity of classroom in the centralized heating area is lower than the standard，and the CO 2 in the classroom in winter is lower than the standard. It is recommended to install heating facilities in schools with low temperatures to increase the temperature and increase the frequency of ventilation in classrooms or adopt mechanical ventilation strategies to reduce CO 2 volume concentration.

Objective: To evaluate the classroom environmental management and CO 2 volume concentration in primary and secondary schools from Liaoning, Tianjin, and Shanghai, thereby providing a scientific basis for developing targeted strategies to improve classroom air quality. Methods: From December 16 to 26, 2024, by using stratified random cluster sampling method, the questionnaire survey was conducted in 72 primary and secondary schools (24 each of primary, junior high, and regular high schools) across Liaoning, Tianjin and Shanghai. Information on heating, ventilation and other classroom environmental management was collected. Additionally, 108 classrooms were selected for on site microclimate measurements, including temperature, humidity, wind speed and CO 2 volume concentration. Univariate analysis and multiple linear regression models were employed to explore related factors of classroom CO 2 volume concentration. Results: Among the three provinces/municipalities, 20.8% of schools regularly monitored the microclimate. The overall compliance rate for classroom CO 2 volume concentration was 17.6%. Multiple linear regression analysis showed that CO 2 volume concentration in regular and junior high school classrooms were higher than in primary school classrooms ( β=0.067, 0.046, 95%CI =0.036-0.099, 0.013-0.080); classrooms ventilated regularly in the morning and afternoon had higher CO 2 volume concentration than those ventilated during every break between classes ( β=0.043, 95%CI = 0.007- 0.080); both temperature ( β=0.010, 95%CI =0.004-0.016) and humidity ( β=0.003, 95%CI =0.002-0.004) were positively correlated with CO 2 volume concentration (all P <0.05). Conclusions Excessive CO 2 volume concentration in primary and secondary school classrooms is a prominent issue, and ventilation frequency is a key intervenable factor for controlling CO 2 levels. It is recommended to promote ventilation during every break between classes as a core management measure and to emphasize air quality supervision in regular high school classrooms.

Objective: To evaluate the current situation of thermal environment in primary and secondary school classrooms during winter, and to analyze students thermal comfort needs, so as to provide a basis for improving classroom thermal environment. Methods: From December 16 to 26, 2024, a stratified cluster random sampling method was used to select 90 classrooms from 15 primary and secondary schools in centralized/air conditioned heating areas(Liaoning Province, Tianjin City, Shanghai City) and naturally ventilated areas(Anhui Province and Jiangxi Province)for on site environmental measurement. A questionnaire survey was conducted among 743 students. The differences between groups using the χ 2 test were compared. Based on actual measurement data, a predicted mean vote prepared percentage of dissatisfied (PMV-PPD) model for centralized/air conditioned classrooms and an adaptive model for naturally ventilated classrooms were established, and the thermal neutral temperature and comfort interval were calculated. Results: The average outdoor temperature during on site measurement was 4.00(0.20，7.00)℃. In classrooms with centralized or air conditioned heating systems, the measured average temperature was (19.33±2.59)℃, with a thermal comfort range of 20.35-25.35 ℃ and a thermal neutral temperature of 22.85 ℃. And 13.92% of students reported feeling cold, while 80.80% felt comfortable. In classrooms with natural ventilation, the measured average temperature was (12.26±1.83)℃, with a thermal neutral temperature of 19.67 ℃ and a thermal comfort range of 16.17-23.17 ℃. About 48.33% of students reported feeling cold, and 49.81 % felt comfortable.The results of univariate analysis showed that there were statistically significant differences in shoe thickness, temperature sensation, relative humidity sensation and wind speed sensation between centralized/air conditioned heating areas ( χ 2= 7.01 , 31.47, 13.57, 13.80,all P <0.05). There were also statistically significant differences in school stage for primary and secondary school students, body mass index, classroom location for seat, temperature sensation, relative humidity sensation and wind speed sensation between naturally ventilated areas ( χ 2=42.13, 11.13, 11.04, 60.39, 29.27, 38.46,all P <0.05). Conclusions There are differences in thermal environment and students subjective thermal comfort in primary and secondary schools under different ventilation modes in winter. The temperature standards for heated classrooms should be revised, and differentiated environmental regulation strategies should be adopted based on different ventilation methods to improve students health and comfort levels.

Objective: To understand the subjective and objective comfort evaluations of students from different age groups on desks and chairs, so as to provide reference for standardized allocation and use of desks and chairs. Methods: From January to April 2024, a total of 2 446 students were selected from 26 schools in 13 districts (counties/cities) in Shanghai, Tianjin, and Wuxi from Jiangsu Province by using cluster random method, including students in kindergartens, primary schools, junior high schools,senior high schools, colleges and universities. Standardized procedures were used to measure the height and weight of participants, and the matching desks and chairs models were selected according to the height. The subjective comfort of students on matching desks and chairs was investigated, and their objective comfort was evaluated by using a self designed questionnaire. The χ 2 test was used to analyze the differences of subjective perception and objective evaluation in comfort between different types of desks and chairs. Results: About 84.1% of the students subjectively thought that large desks and small chairs were very comfortable or relatively comfortable, followed by large desks and chairs (75.7%), and the proportion of small desks and chairs was the lowest among the three types (46.2%), and the difference was statistically significant ( χ 2=722.46, P <0.01). The reporting rates of primary school, junior high school and senior high school students who subjectively considered large desks and chairs to be very comfortable/relatively comfortable were higher than that of other types of desks and chairs, and the differences were statistically significant ( χ 2=297.49, 252.82, 343.67, P <0.01). However, there was no significant difference in the subjective comfort evaluation of different types of desks and chairs among kindergarten children ( χ 2=3.21, P >0.05), and 66.3% of the students in colleges and universities felt very comfortable/relatively comfortable when they used the matching standard desks and chairs. The objective evaluation results of the comfort for the three types of desks and chairs were consistent with the subjective evaluation, but the proportions of the objective evaluation as very comfortable/relatively comfortable were higher than that of the subjective evaluation ( χ 2=20.76- 813.47, P <0.01). Conclusions Large desks and chairs, as well as large desks with small chairs are perceived comfortable, while small desks and chairs are perceived less comfortable. It is recommended to match the large desks and chairs or large desks and small chairs that are suitable for them according to the "standard", to promote physical and mental health of students.

Objective: To investigate the differences in the comfort of desks and chairs furniture among students with different body types according to the standard, so as to provide a reference for guiding students with overweight and obesity to choose the correct study furniture and revising the standards. Methods: From January to April 2024, 2 443 students from 26 schools in 13 districts (counties/cities) in Shanghai, Tianjin, and Jiangsu Province were selected by the cluster random sampling method to conduct physical examination. The subjective and objective evaluations of the comfort of height matched desks and chairs were investigated. The students were divided into non overweight, overweight, and obesity groups according to relevant criteria, and stratified analysis was performed. The χ 2 test was used to analyze differences in the comfort evaluations of desks and chairs among students with different body types. Results: Among the 2 443 students surveyed, 16.7% and 12.6% were respectively classified as overweight and obese. All students assigned the highest comfort ratings to large desks and small chairs (84.1%), and consistency was observed between students subjective and objective evaluations. The reporting rate of samll desks and chairs of obesity students subjective evaluation was lower (36.8%) than that of overweight and non overweight/obesity students (52.1%, 48.0%) ( χ 2=14.63, P <0.01). The overweight and obese group of primary school students had a worse evaluation of the comfort of large desks and chairs and small desks and chairs than those of the non overweight and obese groups( χ 2=15.78, 7.63, P <0.05). Among high school students, the overweight and obese group had worse evaluation of the comfort of large desks and chairs, as well as large desks and small chairs, than those of the non-overweight and obese groups( χ 2=9.62, 11.77, P <0.05). The objective evaluations revealed low compliance ratings on the posture of the thighs and calves for naturally forming an angle greater than 90° (55.6%), and headroom height under the table (50.3%) with small desks and chairs ( χ 2=94.05, 166.47, P <0.05). Conclusions Compared with non overweight/obese students, students with overweight and obese students report poor comfort evaluations of height matched desks and chairs. Revision of the standard should consider the body types of students, and evaluations of the comfort of desks and chairs furniture by students with overweight and obesity should be improved.

Objective To investigate the effect of pramlintide,a pancreatic amyloid peptide analog,on learning and memory of Alzheimer's disease(AD)mice through antioxidant stress,and to determine the expression of phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway.Methods The APP/PS1 mice were divided into a pramlintide treatment group(intraperitoneal injection of 0.5 μmol/L per day for 10 weeks)and an AD group(same dose of PBS),with 5 mice in each group.The learning and memory abilities were detected with water maze test,the pathological changes of the hippocampus were observed with HE staining and immunohistochemistry,the morphological characteristics of dendritic spines in hippocampus were observed after Golgi staining,and the ultrastructure of hippocampal neurons was observed through transmission electron microscopy(TEM).The content of malondialdehyde(MDA)and the level of superoxide dismutase(SOD)in the hippocampal tissue were detected by biochemical assay,and the levels of inflammatory factors IL-6,TNF-α and IL-1β were determined with ELISA.Western blotting was applied to measure the expression of PI3K/Akt signaling pathway related proteins in the hippocampus.In the cell experiment,SH-SY5Y cells were added with Aβ 1-42 to establish a cell model of AD.After the cells were treated with pramlintide,the levels of oxidative stress and inflammatory response were detected,and cell apoptosis was detected by immunofluorescence.Results The animal experiments showed that pramlintide treatment resulted in significantly shortened escape latency(P<0.01),increased platform crossings(P<0.01),and prolonged time to exploring hidden platform(P<0.01).In the hippocampal tissue of the pramlintide treatment group,HE staining displayed hippocampal neurons in high density and neat arrangement(P<0.05),immunohistochemical results showed significantly reduced Aβ protein(P<0.01),Golgi staining results demonstrated more dendritic spines(P<0.05),TEM revealed almost intact neuronal mitochondrial structure,with reduced vacuolization and clear and identifiable morphology.When compared with the AD group,the levels of oxidative stress and inflammatory response were decreased(P<0.01),and the relative expression of p-PI3K/PI3K and p-Akt/Akt proteins was increased(P<0.01)in the treatment group.In cell experiments,the levels of oxidative stress and inflammatory response were decreased in AD cell model after pramlintide treatment(P<0.01),and the results of immunofluorescence showed that cell apoptosis was declined(P<0.01).Conclusion Pramlintide can improve the cognitive function,reduce the hippocampal deposition of Aβ,reduce oxidative stress and inflammatory response,alleviate the pathological changes of neuronal ultrastructure,and enhance the expression of PI3K/Akt signaling pathway in AD mice.

OBJECTIVE To analyze the manager post competency evaluation scale in central sterile supply depart-ment based on the iceberg model and test its reliability and validity.METHODS A pool of items was constructed based on literature research and semi-structured interviews.The scale was further refined through expert meetings and a pilot survey.A convenience sampling method was used to select 362 managers from central sterile supply de-partments in medical institutions at various levels in Hunan Province in Jan.2024 as survey subjects.Question-naires were administered,and the reliability and validity of the scale were tested.RESULTS The final version of the scale encompassed five dimensions:personal traits,management abilities,professional abilities,other abili-ties,professional knowledge and skills,with a total of 39 items.The item-level validity coefficients of the scale ranged from 0.83 to 1.00,and the content validity index was 0.93.Exploratory factor analysis revealed a Bartlett's test value of 4 723.828(P＜0.001),a KMO test coefficient of 0.937 and a cumulative variance explanation rate of 74.34％for the five common factors.Confirmatory factor analysis results indicated that the root mean square error of approximation(RSEMA)was＜0.08,the root mean square residual(RMR)was＜0.05,and both the incre-mental fit index(IFI)and comparative fit index(CFI)were＞0.9.The Cronbach's α coefficient of the scale was 0.977,the split-half reliability was 0.955,and the test-retest reliability was 0.952.CONCLUSIONS The manager post competency evaluation scale in central sterile supply departments developed in this study demonstrates rela-tively good reliability and validity.It can effectively evaluate manager post competency and provide references for improving related evaluation systems and optimizing training programs.

Objective:To investigate the efficacy and prognosis of biliary drainage via endoscopic retrograde cholangiopancreatography (ERCP) before steroid therapy in treating autoimmune pancreatitis (AIP) complicated with obstructive jaundice.Methods:A retrospective analysis was performed on clinical data of patients with AIP complicated with obstructive jaundice who received steroid therapy at the First Affiliated Hospital of Naval Medical University from 2010 to 2023. Patients were divided into a drainage group (receiving ERCP biliary drainage before steroid therapy) and a steroid group (receiving only steroid therapy). Short-term efficacy, long-term efficacy, hospitalization costs and postoperative complications of ERCP biliary drainage were compared between the two groups.Results:A total of 69 patients were included, with 32 in the drainage group, aged 62.78±11.21 years, which demonstrated significantly higher costs (34 816.57±11 688.85 yuan VS 16 518.50±6 544.37 yuan, t=7.0, P<0.001), with 25.00% (8/32) experiencing ERCP-related complications, compared with 37 patients in the steroid group, aged 55.41±2.15 years. There was no significant difference in hospitalization duration between the drainage group (10.38±4.56 days) and the steroid group (8.95±4.99 days, t=1.2, P=0.219). After 1 month of treatment, total bilirubin [118.5 (76.2, 309.3) μmol/L VS 48.7 (30.5, 148.4) μmol/L, U=1 728.5, P<0.001] and direct bilirubin [84.5 (47.7, 236.3) μmol/L VS 37.7 (18.3, 105.7) μmol/L, U=1 588.5, P=0.001] levels in the drainage group remained higher than those in the steroid group, while alanine aminotransferase levels were lower [74.0 (46.5,110.5) U/L VS 143.0 (51.0,253.5) U/L, U=769.0, P=0.006]. No significant differences were observed in these biochemical indices between the two groups at 4-month and 12-month follow-ups ( P>0.05). The recurrence rates were 28.1% (9/32) in the drainage group and 21.6% (8/37) in the steroid group, with no significant difference in recurrence rate between groups ( χ2=0.4, P=0.266). Conclusion:ERCP biliary drainage does not significantly improve long-term efficacy or reduce recurrence rates in AIP patients with obstructive jaundice. Instead, it increases the risk of postoperative complications and medical costs. Direct steroid therapy is safe and feasible for confirmed AIP with obstructive jaundice.

OBJECTIVE:To systematically evaluate the correlation between phase angle and sarcopenia and its diagnostic indexes.METHODS:The PubMed,EMbase,Cochrane Library,Web of Science,CNKI,WanFang Data,VIP and SinoMed databases were electronically searched to collect studies on the correlation between phase angle and sarcopenia and its diagnostic indexes from database inception to May 8,2024. Two reviewers independently screened literature,extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.3 and Stata 14.0 software. RESULTS:A total of 50 eligible articles were included. Meta-analysis results showed that compared with the non-sarcopenic population,the phase angle was significantly reduced in sarcopenic patients[standardized mean difference (SMD)=-0.99,95％ confidence interval (CI) (-1.09,-0.90),P<0.00001]. The results of subgroup analysis indicated that the difference of phase angle was more significant in patients with severe sarcopenia and Asian sarcopenia. Moreover,reduction in the phase angle was more obvious in patients with malignant tumors and respiratory diseases with sarcopenia. And skeletal muscle mass index (Pearson's r=0.565,P<0.00001),grip strength (Pearson's r=0.446,P<0.00001),and gait speed (Pearson's r=0.405,P<0.00001) all showed a moderate positive correlation with phase angle. However,appendicular skeletal muscle mass index showed a very weak positive correlation with phase angle (Pearson's r=0.139,P=0.02). CONCLUSION:Phase angle has a significant difference between sarcopenia and non-sarcopenia population,and it is correlated with the diagnostic indexes of sarcopenia to different extents. It suggests that phase angle has some clinical values in the objective diagnosis of sarcopenia. However,the results may be influenced by some factors such as sarcopenia severity and detection instruments of phase angle. Due to the limited quality and quantity of the included studies,more high-quality studies are needed to verify the above conclusion.