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 explore the effects of leonurine on growth arrest-specific protein-6 （GAS6）/Axl signaling pathway， and clarify its mechanism of alleviating myocardial injury in rats with coronary heart disease. METHODS The rat model of coronary heart disease was constructed； successfully modeled rats were randomly separated into model group， leonurine low- dose and high-dose groups （intragastric administration of leonurine 25， 100 mg/kg+intraperitoneal injection of normal saline 75 mg/kg）， and leonurine high-dose+GAS6/Axl signaling pathway inhibitor group （intragastric administration of leonurine 100 mg/kg+ intraperitoneal injection of R428 75 mg/kg）， with 12 rats in each group. Additional 12 normal rats were selected as control group. Each administration group was given relevant medicine； control group and model group were given a constant volume of normal saline intragastrically and intraperitoneally， once a day， for 48 consecutive days. After administration， the heart function of rats， and serum levels of inflammatory factors and myocardial injury markers were detected； the pathological morphology of myocardial tissue was observed； the myocardial cell apoptosis rate， the expressions of apoptosis and GAS6/Axl signaling pathway-related proteins were determined. RESULTS Compared with control group， model group showed disorders in the arrangement of myocardial cells and myocardial fibers， hypertrophy of myocardial cells， and nuclear condensation； left ventricular ejection fraction， left ventricular fractional shortening， ratio of early-diastolic and late-diastolic motion velocity of the mitral ring， the protein expression of GAS6， B-cell lymphoma 2/B-cell lymphoma 2 associated X protein and phosphorylated Axl/Axl ratios were decreased significantly （P＜0.05）. The levels of tumor necrosis factor-α， interleukin-1β， interleukin-6， creatine kinase isoenzyme， troponin Ⅰ and myoglobin， the cell apoptosis rate， and cleaved caspase-3/caspase-3 ratio were increased significantly （P＜0.05）. Leonurine could obviously improve the above pathological conditions and detection indicators （P＜0.05）， and the effect of leonurine high-dose group was more significant than that of leonurine low-dose group （P＜0.05）； R428 treatment could reverse the ameliorating effect of high-dose of leonurine on myocardial injury in rats with coronary heart disease （P＜0.05）. CONCLUSIONS Leonurine can alleviate myocardial injury in rats with coronary heart disease， and its mechanism of action is related to the activation of the GAS6/Axl signaling pathway.

It is believed that patients with cirrhotic ascites exhibit a pathological mechanism characterized by the decline of healthy qi and the accumulation of pathogenic factors. Clinically， treatment should be based on the theory of tonification and purging， with a staged approach distinguishing between the active phase and the remission phase. The balance between tonification and purging should be adjusted according to the progression of pathogenic and healthy actors. In the acute phase， purging should take precedence over tonification， using purging as a means of tonification to facilitate the flow of water and qi through the triple energizer. The severity of water retention， dampness， blood stasis， and heat should be carefully assessed to ensure thorough elimination of pathogenic factors while avoiding harm to healthy qi. Medication adjustments should be made once the pathogenic factors are significantly weakened. In the remission phase， an integrated approach combining both tonification and purging should be adopted， incorporating purging within tonification to clear residual pathogens and prevent recurrence. Concurrently， proactive treatment of the underlying disease is essential to achieve complete recovery and prevent the recurrence of ascites.

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 understand the home reading-writing levels among children and adolescents in Shanghai after school, and to explore its association with screening myopia, so as to provide a scientific basis for the prevention and control of myopia. Methods: From April to December 2024, 641 primary and middle school students were recruited from 2 urban schools and 1 rural school in Shanghai to participate in the survey. An illuminance meter was used to measure the illuminance of home reading-writing activities after school. Screening myopia was determined through visual acuity examination and refractive detection under non ciliary muscle paralysis conditions among children and adolescents. A binary Logistic regression model was used to analyze the association between home reading-writing illuminance and screening myopia. Results: The detection rate of screening myopia among children and adolescents in Shanghai was 59.9%. The median home reading-writing illuminance after school was 340.9(112.2, 753.5) lx, and 45.4% was found of less than 300 lx. The family illuminance in the primary school stage [432.0 (136.9, 837.0) lx] was higher than that in the junior high school stage [113.1(53.7, 375.1) lx], and main urban area group [503.9 (212.6, 969.5) lx] was higher than that in the rural group [141.6 (53.7, 416.9) lx], the differences were statistically significant (Z=-7.56, -9.95,both P<0.05). The results of Logistic regression analysis showed that compared with the family illuminance of 150-500 lx, children and adolescents with family illuminance<150 and >500 lx had increased risks of screening myopia detection[OR(95%CI)=1.56(1.01-2.42), 1.74(1.15-2.62),both P<0.05]. Conclusions The home reading-writing illuminance after school is suboptimal. Both excessively low and high home reading-writing illuminance levels are associated with screen-detected myopia. It is necessary for children and adolescents to improve lighting conditions during evening reading-writing activities, and strengthen health education according to different regions and school stages.

Objective: To understand the indoor light at night (LAN) exposure intensity during sleep among children and adolescents in Shanghai, so as to provide a basis for exploring potential health risks and formulating effective interventions. Methods: From April to December in 2024, a total of 628 students in grades 4-7 were recruited from three schools in Shanghai. A portable illuminance meter was used to measure LAN for one week, and participants recorded their sleep time. The Kruskal-Wallis H- test was used for comparison between groups, and the error bar chart was used to show the trend and variation range of average LAN exposure intensity in different sleep periods. Results: The indoor LAN exposure intensity of children and adolescents in Shanghai was [2.4(0.8, 5.9)lx] during sleep, and 28.8% of children and adolescents were exposed to indoor LAN≥5 lx. There was no significant differences in indoor LAN exposure intensity between boys [2.4(1.0, 5.9)lx] and girls [2.3(0.7, 5.9)lx] ( Z=-0.86, P > 0.05 ). The indoor LAN exposure intensity of primary school students [2.9(1.1, 6.6)lx] was higher than that of junior high school students [1.0(0.3, 3.1)lx] ( Z =-5.87), and indoor LAN exposure intensity of students in the main urban area [3.2(1.1, 7.8)lx] was higher than that of rural students [1.6(0.5, 4.3)lx] ( Z =-5.23)(both P <0.05). The indoor LAN exposure intensity showed an overall decreasing trend during sleep of children and adolescents ( tau=-0.81, P =0.02), with a slight increase before waking up. Conclusions Indoor LAN exposure intensity among children and adolescents in Shanghai is generally high, especially among primary school students and students living in the main urban area. Health policy and education should be strengthened to reduce the impact of LAN on children and adolescent health.