Objective To explore the associations between traumatic exposure and self-harm behaviors, and the mediating effect of self-esteem in this relationship, and to provide a theoretical basis for preventing self-harm behaviours among middle school students. Methods Data were derived from the 2022 Mental Health Survey of Primary and Secondary School Students in Hunan Province, including a total of 15 105 middle school students aged 12-18 years. The traumatic events, traumatic experiences, self-harm behaviors, self-esteem, and other related factors among these students were assessed by the Hunan Mental Health Assessment Questionnaire for Primary and Secondary School Students. Considering the school-level as a random effect, binary logistic regression models were established to analyze the associations between traumatic exposure (and its subtypes) and self-harm behaviors. The stepwise testing method was employed for mediating effect analysis to examine the mediating role of self-esteem in the associations between traumatic exposure (and its subtypes) and self-harm behaviors. The proportion of the indirect effect to the total effect was calculated to determine the mediating effect size. Results The reported rate of self-harm behaviors among middle school students in Hunan Province in the past year was 7.3% (N=1 106). Middle school students who reported self-harm behavior had significantly lower self-esteem scores than those without (24.31±4.83 vs 29.26±4.96, P<0.001). Logistic regression results showed that the risk of self-harm behavior was 10.55 times higher among those with traumatic event exposure compared to those without (OR=10.55, 95%CI: 5.00-22.26, P<0.001), and 26.39 times higher among those with a traumatic experience score ≥4 points compared to those without traumatic experience (OR=26.39, 95%CI: 12.42-56.05, P<0.001). All subtypes of traumatic events and traumatic experiences were positively associated with self-harm behaviors (all P<0.001). Self-esteem partially mediated the associations between traumatic events, traumatic experiences (including all their subtypes), and self-harm behaviors, with mediation proportions ranging from 13.04% to 25.15% (all P<0.001). Among these, the mediation proportion was highest for life-threatening events/experiences, at 22.78% and 25.15%, respectively. Conclusion Traumatic exposure may increase the risk of self-harm behaviors among middle school students, and self-esteem plays a partial mediating role in this association.

Objective To explore the correlation between daily free sugar intake and Sleep Disorders (SD) among middle school students, so as to provide insights for developing measures to promote healthy diets and improve sleep quality in middle school students. Methods A total of 1 905 middle school students from the first follow-up survey of the Chinese Adolescent Health Growth Cohort in 2022 were included as study subjects. The daily free sugar intake was assessed with a semi-quantitative food frequency questionnaire, and sleep disorders were evaluated with the Pittsburgh Sleep Quality Index questionnaire. Binary logistic regression analysis was performed to find the correlation and gender differences. Results The reported rate of SD among middle school students was 22.6%. The results of Chi-square test revealed that there was a statistically significant difference in SD distribution among different free sugar intake groups (χ2=23.08, P<0.05). After adjusting for confounding factors such as gender, region, family type, discipline style, academic pressure, and social support, the results of binary logistic regression model showed that the risk of SD was higher in the group with high free sugar intake compared with the low intake group (OR=1.91, 95%CI: 1.42-2.56, P<0.01). Furthermore, high free sugar intake from both sugar-sweetened beverages and food contributed to a higher risk of SD among middle school students (OR=1.92, 95%CI: 1.41-2.61; OR=1.88, 95%CI: 1.44-2.44, both P<0.01); the results of stratified analysis by gender showed that the correlation between daily free sugar intake and the risk of SD was only observed in the male population (OR=2.22, 95%CI: 1.51-3.25, P<0.01). Conclusion Regardless of food sources, high daily sugar intake may be associated with SD and this correlation is primarily observed among male students.

Objective To explore the current prevalence of Internet addiction and depressive symptoms among middle school students in Kunming, analyze their associations and influencing factors, and to provide a reference for relevant authorities to formulate intervention measures for key groups. Methods Based on the 2024 survey data from the Common Diseases and Health Risk Factors Surveillance Project involving 12 246 middle school students in Kunming, the detection rates of Internet addiction and depressive symptoms and their group differences were compared. Logistic regression and Restricted Cubic Splines (RCS) were used to analyze the associations between Internet addiction and depressive symptoms and their influencing factors. Results The detection rate of Internet addiction among middle school students in Kunming was 4.11%, and the detection rate of depressive symptoms was 23.74%. The detection rate of depressive symptoms among females (27.84%) was higher than that of males (19.52%). The detection rates of Internet addiction and depressive symptoms among high school students and boarding students were higher than those in junior high school students and non-boarding students. Among different family structures, the detection rate of depressive symptoms was higher in intergenerational household (32.43%). There was a positive association between Internet addiction and the detection of depressive symptoms. Compared with students in the non-Internet addiction group, students in the Internet addiction group had an increased risk of depression detection. The OR values of single-factor analysis model 1, model 2, and model 3 adjusted for confounding factors were 5.92 (95%CI: 4.91-7.12), 6.11 (95%CI: 5.05-7.39), and 4.37 (95%CI: 3.57-5.36), respectively. The RCS curve exhibited an approximate J-shaped curve, indicating that the risk of depressive symptoms in students increased with the Internet duration. Female sex, boarding status, extended family structure, reconstituted family, injuries, campus bullying, smoking, drinking, and use of addictive substances were promoting factors for the comorbidity of Internet addiction and depression, while seeking help for psychological problems was a protective factor against comorbidity. Conclusions Non-linear associations exist between Internet addiction and depressive symptoms in students. Therefore, relevant measures targeting the comorbid factors of Internet addiction and depression should be formulated and implemented to curb the accelerating growth of Internet addiction and depression in children and adolescents.

Objective To explore the mediating role of depressive symptoms between family environment and unintentional injuries among middle school students, and to provide a theoretical basis and feasible intervention pathways for the prevention and control of unintentional injuries in this targeted population. Methods From August to September 2025, a stratified random cluster sampling method was employed to select 1 186 middle school students from four prefectures and cities in Yunnan Province. A questionnaire survey was conducted using a general information questionnaire, an unintentional injury survey form, the Family Belonging Scale, and the Center for Epidemiologic Studies Depression Scale (CES-D). Spearman correlation analysis was performed using SPSS 26.0, and Bootstrap mediation effect testing (with 5 000 resamples) was conducted using the PROCESS v 4.2 macro. Results The self-reported incidence rate of unintentional injuries among middle school students was 20.40%. Each dimension of the family environment was negatively correlated with the depressive symptoms and unintentional injuries (r=-0.43 to -0.47, -0.28 to -0.30), depressive symptoms were positively correlated with unintentional injuries (r=0.25, all P<0.01). Mediating effect analysis showed that depressive symptoms played a partial mediating role between family environment and unintentional injuries, with an indirect effect value of -0.01 (Boot SE=0.01), accounting for 15.73% of the total effect. After controlling for gender, educational stage, ethnicity, family economic level, and sleep duration, the mediating effect remained statistically significant, contributing 16.47% of the total effect. Dimensional comparisons revealed that the mediating effect proportion of the family support dimension through depressive symptoms (22.18%) was higher than that of family attachment (20.81%) and family belonging (19.10%). Conclusions Family environment negatively predicts unintentional injuries among middle school students, with depressive symptoms playing a partial mediating role. The emotional pathway via family support demonstrates relatively stronger indirect influence. Prevention strategies should adopt a dual-path approach—improving family functioning and identifying depressive symptoms—with particular emphasis on enhancing supportive family interactions.

Objective To explore the relationships between family economic strain awareness, smartphone dependence, and insomnia symptoms in adolescents, and to examine the mediating role of smartphone dependence. Methods A multi-stage stratified cluster random sampling method was employed. Self-administered questionnaires, including a demographic questionnaire, the Family Economic Strain Scale, the Self-rating Questionnaire for Adolescent Problematic Smartphone Use, and the Adolescent Insomnia Self-Rating Scale, were distributed to middle school students in Guangxi. Results A total of 1 729 participants were included in this study. The detection rates of mild, moderate, and severe insomnia among adolescents were 22.3%, 14.5%, and 11.1%, respectively. Family economic strain awareness was positively correlated with smartphone dependence and insomnia symptoms (P<0.01). Multiple linear regression analysis showed that when both family economic strain awareness and smartphone dependence were included in the regression model, they were positively correlated with adolescent insomnia symptoms (β=0.072, P<0.01; β=0.265, P<0.001). Mediating effect analysis revealed that smartphone dependence partially mediated the relationships between family economic strain awareness and adolescent insomnia symptoms, with an effect value of 0.083 (95%CI: 0.062-0.105), accounting for 53.5% of the total effect. Conclusions Family economic strain awareness may aggravate adolescent insomnia symptoms by increasing smartphone dependence. When assisting adolescents with financial difficulties, relevant departments should also pay attention to both material and psychological assistance, encourage them to participate in group activities, reduce their dependence on smartphones, and thereby improve insomnia symptoms to some extent.

Objective To investigate the current status of visual development among preschool children in an urban district of Beijing, and to provide data supporting for formulating effective measures to protect children’s emmetropization reserves and advance myopia prevention and control to the preschool stage. Methods In November 2025, a census-based survey was conducted to perform vision examinations on all 5 957 preschool children aged 3-6 years attending public kindergartens in the urban district of Beijing. Biological parameters including refractive status and axial length were analyzed using descriptive and correlation analyses. Pearson correlation and multiple linear regression were employed to assess correlations among ocular biometric parameters. Results The mean Spherical Equivalent (SE) refraction of preschool children was +0.96 D, and the mean Axial Length (AL) was 22.26 mm. The detection rate of suspected insufficient emmetropization reserve was 4.0%, and the detection rate of abnormal axial length was 57.8%. Pearson correlation analysis showed that SE was significantly negatively correlated with AL, corneal curvature, and the Axial Length-to-Corneal Radius ratio (AL/CR) (all P<0.001). Multiple linear regression analysis revealed the emmetropization reserve was also negatively correlated with AL/CR (β=-3.926, P=0.025), with the strongest correlation observed in the 5-year-old group (β=-6.190 6, P=0.038). Conclusion Preschool children across all age groups face a certain risk of insufficient emmetropization reserve. In the absence of cycloplegia, AL/CR serves as the optimal indicator for predicting the risk of insufficient emmetropization reserve.

Objective To analyze changes in the disease burden of tumors among adolescents aged 10-24 years in China from 1990 to 2021, and to provide a scientific basis for formulating tumor prevention and control strategies for adolescents. Methods In March 2025, disease burden data of tumors among adolescents aged 10-24 years in China from 1990 to 2021, including incidence, mortality, Disability-Adjusted Life Years (DALY), Years of Life Lost (YLL), and Years Lived with Disability (YLD), were extracted from the Global Burden of Disease (GBD) 2021 database. Joinpoint software was used to analyze the temporal changing trends in disease burden, and the Bayesian Age-Period-Cohort (BAPC) model was applied to predict the age-standardized incidence rate, mortality rate, DALY rate, YLL rate, and YLD rate of tumors among adolescents in China from 2022 to 2040. Results Compared with 1990, in 2021, the mortality, DALY rate, and YLL rate of tumors among adolescents aged 10-24 years in China decreased by 42.92%, 42.21%, and 42.93%, respectively, with age-standardized rates decreasing by 41.37%, 41.22%, and 41.96%, respectively. The incidence and YLD rate of tumors among adolescents in China increased by 20.71% and 51.27%, respectively, with age-standardized rates increasing by 24.72% and 56.68%, respectively. In 2021, the incidence of tumors among male adolescents in China increased by 23.16% compared to 1990, while the incidence among females increased by 17.53%. Joinpoint regression analysis showed that during 1990-2021, the age-standardized mortality, DALY rate, and YLL rate of tumors among adolescents aged 20-24 years in China exhibited an overall downward trend (AAPCmortality=-1.71%, AAPCDALY=-1.70%, AAPCYLL=-1.74%, all P<0.05), whereas the age-standardized incidence and YLD rate showed an overall upward trend (AAPCincidence =0.68%, AAPCYLD =1.47%, both P<0.05). The BAPC model indicated that from 2022 to 2040, the age-standardized incidence and YLD rate of tumors among adolescents aged 10-24 years in China would continue to rise, reaching 17.55/100 000 and 9.02/100 000, respectively, representing increases of 11.85% and 16.54% compared to 2021. The age-standardized mortality, DALY rate, and YLL rate were projected to increase slightly, reaching 5.50/100 000, 397.65/100 000, and 388.37/100 000 by 2040, representing increases of 3.77%, 2.90%, and 2.55% compared to 2021. From 2022 to 2040, the disease burden of tumors among male adolescents was expected to remain higher compared to females. Conclusions From 1990 to 2021, the age-standardized mortality rate, DALY rate, and YLL rate of tumors among adolescents aged 10-24 years in China decreased, while the age-standardized incidence and YLD rate increased. Predictions show that the disease burden of tumors among adolescents in China will continue to increase from 2022 to 2040. The situation for tumor prevention and control among adolescents in China is difficult. It is necessary to further strengthen science popularization related to adolescents’ tumor prevention and treatment, enhance the monitoring and intervention of risk factors for tumors, and especially focus on male adolescents to improve their awareness and capacity in tumor prevention and treatment, thereby reducing the incidence of tumors among adolescents.

Objective To investigate and analyze the current status of tableware cleaning and disinfection in school canteens in Hunan Province, identify weak links and major potential risks in the cleaning and disinfection process, and to provide a reference for formulating corresponding food safety management requirements. Methods A multi-stage stratified random sampling method was adopted. In 2024, 364 schools in Hunan Province were selected for on-site investigation. The surveyed items included the setup of cleaning and disinfection areas, floor area of cleaning and disinfection areas, maximum number of diners, and configuration of equipment and facilities across different regions and types of schools. The χ2 test, Fisher’s exact test or Fisher-Freeman-Halton exact test were used to compare differences among different regions, school types, and urban/rural areas, so as to understand the current management status of tableware cleaning and disinfection in school canteens. Results The survey found that the overall installation rate of independent cleaning and disinfection areas reached 99.0%; however, the overall compliance rate of floor area for cleaning and disinfection areas was only 60.7%, indicating generally insufficient area. Schools at the basic education stage were identified as the priority for improvement. Only about 75.8% of canteens considered their disinfection equipment adequate, and the compliance rate for sanitation facilities was merely 63.5%, with significant differences across educational levels—universities had the highest rates, while junior high schools and kindergartens were relatively weak. Conclusions Currently, the primary contradiction regarding tableware safety in school canteens has shifted from the “presence or absence” of basic infrastructure to issues such as the rationality of functional area layout, adequacy of equipment and facilities, and balance of financial support. These factors may increase the risk of food safety hazards. It is recommended to systematically promote improvements from aspects including optimizing infrastructure configuration, strengthening supervision and accountability mechanisms, refining regulations, and enhancing personnel management.

Objective To analyze the current situation and influencing factors of e-cigarette trial use among adolescents in Chaoyang District, Beijing, and to provide a basis for comprehensive prevention and control of e-cigarette use among adolescents in the district. Methods In September to October 2023, a stratified random cluster sampling method was used to select 2 vocational high schools, 4 senior-high schools, and 6 middle schools in Chaoyang District. The “China Adolescent Tobacco Use Survey Questionnaire” was used to investigate e-cigarette trial use and the awareness of e-cigarette harm among adolescents. Logistic regression was used to analyze the factors influencing adolescents’ e-cigarette trial use. Results A total of 1 810 middle school students were included, with an e-cigarette trial use rate of 5.25%. Multivariate analysis results showed that attending vocational high school (OR=2.414, 95%CI: 1.313-4.439), having pocket money (OR=3.036, 95%CI: 1.399-6.588), believing that smoking makes young people more attractive (OR=2.393, 95%CI: 1.134-5.052), having at least one parent who smokes (OR=1.686, 95%CI: 1.029-2.762), having friends who smoke (OR=5.814, 95%CI: 3.492-9.679), and seeing people smoke in e-cigarette media (OR=2.101, 95%CI: 1.051-4.202) were risk factors for e-cigarette trial use. Believing that e-cigarette use is addictive (OR=0.263, 95%CI: 0.140-0.496) was a protective factor against e-cigarette trial use. Conclusions The e-cigarette trial use rate among adolescents in Chaoyang District is at a relatively low level, but health risks persist. Future efforts could focus on key populations such as vocational high school students and adolescents with disposable pocket money, strengthen health education regarding the harms of e-cigarettes, promote school-family collaboration, and advance smoke-free environment construction to further reduce e-cigarette use.

Objective To investigate the current status of first-aid knowledge among freshmen at Chongqing University in 2024, and to evaluate the effect of students’ first-aid knowledge levels of the training conducted during military training among freshmen in higher education institutions. Methods In September 2024, a stratified cluster random sampling method was adopted during the freshman military training period at Chongqing University. A self-designed online questionnaire was administered before and after first-aid training to 1 077 freshmen. The questionnaire primarily covered first-aid knowledge related to Cardiopulmonary Resuscitation (CPR)hemostasis, and bandaging. Paired chi-square tests and paired t-tests were used to compare the awareness rates of relevant first-aid knowledge before and after training, as well as willingness to perform CPR. Results A total of 1 028 matched valid questionnaires were collected, with an effective response rate of 95.45%. Before training, the average CPR knowledge scores were only 58.05±22.63, and the average hemostasis and bandaging knowledge scores were 29.96±12.93. Only 25.70% of students expressed willingness to perform CPR on a cardiac arrest victim. After training, the average CPR knowledge scores increased to 89.33±10.82, and the average hemostasis and bandaging knowledge scores rose to 43.24±8.90. Post-training scores were significantly higher than pre-training scores (all P<0.05). The proportion of students willing to perform CPR increased to 91.90% (95%CI: 90.30%-93.60%), representing a significant improvement in willingness to perform CPR (P<0.05). Conclusions The first-aid knowledge among freshmen is relatively limited. The first-aid knowledge training delivered during the military training period significantly improve their mastery of first-aid knowledge and enhance their willingness to act in emergencies.

Objective To analyze the epidemiological characteristics of infectious disease outbreaks in schools in Shuyang County from 2015 to 2024, and to provide a scientific basis for the effective response to school infectious diseases. Methods Data about infectious disease outbreaks in schools of Shuyang County from 2015 to 2024 were collected from the national “Public Health Emergency Management Information System” and the “China Influenza Surveillance Information System”. Descriptive epidemiological methods were used to analyze the temporal, spatial, and population distributions, as well as the disease types involved. Results Over the 10-year period, Shuyang County reported a total of 29 infectious disease outbreaks in school settings. The number of outbreaks first increased and then decreased, peaking in 2017 with 11 outbreaks. Among these outbreaks, 20 (68.97%) were legally notifiable infectious diseases, and 9 (31.03%) were other categories. A cumulative total of 768 cases were reported, affecting 84 575 individuals, with an attack rate of 0.91%, and no deaths occurred. The epidemic peak was mainly concentrated in November and December. Outbreaks occurred in kindergartens (5 outbreaks), primary schools (16 outbreaks), and secondary schools (8 outbreaks), with incidence rates of 3.85%, 24.62%, and 12.70%, respectively, showing statistically significant differences (χ2=18.92, P<0.001). Respiratory infectious diseases constituted the majority of events, primarily influenza and varicella. Among the 29 school outbreaks, 9 occurred in urban schools and 20 in township schools, with incidence rates of 0.58% and 1.29%, respectively, with no statistically significant differences (χ2=1.08, P=0.300). The primary mode of outbreak detection was active reporting by schools (21 outbreaks, 72.41%). Conclusions From 2015 to 2024, the number of infectious disease outbreaks in schools in Shuyang County shows a trend of initial increase followed by decline. The regional distribution indicates a higher outbreak burden in primary and secondary schools compared to kindergartens. These findings suggest that primary and secondary schools should be prioritized as key settings, with strengthened symptom surveillance and outbreak reporting systems, promotion of vaccination, comprehensive enhancement of early detection and rapid response capabilities, and implementation of integrated prevention and control measures.

Objective To investigate the current prevalence of overweight and obesity among primary and secondary school students in a district of Beijing, and to provide data support for formulating targeted intervention measures. Methods From 2022 to 2024, a stratified cluster random sampling method was employed to investigate the current status of overweight and obesity among 7 615 primary and secondary school students in a district of Beijing. Statistical analysis was performed using SPSS 20.0 software. The trend χ2 test was used for comparisons between groups, and the trend chi-square test was used to analyze the changing trend of rates. Results From 2022 to 2024, the overall overweight and obesity rates among primary and secondary school students in a district of Beijing were 18.58% and 22.80%, respectively. The overweight rates (21.30%) and obesity rates (28.76%) in boys were higher than those in girls (15.75% and 16.58%, respectively), with statistically significant differences (χ2=38.692, 160.225, both P<0.001). The overweight rates showed an upward trend with the advancement of school stages, showing statistically significant differences (χ2trend=35.311, P<0.001). There were significant differences in obesity rates across different school stages (χ2=11.177, P=0.004). The obesity rates of primary schools and senior high schools were higher than those of junior high schools (χ2=11.038, 6.185, both P<0.017). From 2022 to 2024, the obesity rates among primary and secondary school students were 24.99%, 23.29%, and 20.23%, respectively, showing a year-by-year downward trend, with statistically significant differences (χ2trend=16.584, P<0.001). The obesity rates of primary schools and senior high schools/vocational high schools also showed a year-by-year downward trend (all P<0.05). Conclusions From 2022 to 2024, the prevention and control of overweight and obesity in a district of Beijing remains challenging, with a year-by-year downward trend in obesity rates. Priority should be given to addressing the issues of overweight and obesity rates among boys and senior high school students, as well as the obesity rates among primary school students. Prevention and control strategies should be further optimized based on gender and school stage differences, and the implementation of a coordinated “government-school-family-society” approach, along with personalized interventions, should be strengthened.

Objective To analyze the distribution characteristics of growth, development levels, and nutritional status among primary and secondary school students in Wuxi County, and to provide a scientific basis for formulating regional student health intervention strategies. Methods Based on the Chongqing Student Common Diseases and Health Influencing Factors Monitoring Project, a total of 28 283 primary and secondary school students from 2019, 2021, and 2023 were included as the study subjects. Physical measurements (height and weight) were conducted. Linear regression analysis was used to analyze growth and development trends, while the rank-sum test and trend test were employed to analyze differences in nutritional status distribution and changing trends among groups. Results Height and weight of primary and secondary school students in Wuxi County showed a significant increase with age (P<0.001). The rates of undernutrition and overweight/obesity were 4.36% and 23.63%, respectively, with the latter showing a significant upward trend (χ2trend=24.324, P<0.001). Boys had higher rates of both overweight/obesity (26.68%) and undernutrition (5.66%) compared with girls (20.46% and 3.00%, respectively). In most age groups, the height and weight of urban students were higher than those of township students. The overweight/obesity rate in urban students (25.19%) was higher than that in township students (20.23%), while the undernutrition rate (3.66%) was lower than in township students (5.89%). Conclusions Primary and secondary school students in Wuxi County face coexisting challenges of uneven growth development and a double burden of malnutrition, which are most prominent among boys. There is a need to establish a multi-tiered and targeted intervention strategy.

Objective To construct a rat model of acute exacerbation of pulmonary fibrosis and investigate the pathogenesis of Acute Exacerbation of Idiopathic Pulmonary Fibrosis (AE-IPF). Methods A rat model of acute exacerbation of pulmonary fibrosis was constructed using Bleomycin (BLM) combined with Lipopolysaccharide (LPS), along with Phosphate-Buffered Saline (PBS). Rats were randomly divided into the following four groups: control group (PBS + PBS), BLM (4 mg/kg) +LPS (2 mg/kg) group, BLM (5 mg/kg) + LPS (1 mg/kg) group, and BLM (5 mg/kg) + LPS (2 mg/kg) group. On day 0, 100 μL of 4 mg/kg and 5 mg/kg BLM, or an equal volume of PBS, was administered intratracheally. On day 14, 50 μL of 1 mg/kg and 2 mg/kg LPS, or an equal volume of PBS, was administered intratracheally. On day 15, the modeling procedure was completed. The lung tissues from rats were collected for Hematoxylin-Eosin (HE) staining and Masson staining. Bronchoalveolar Lavage Fluid (BALF) was collected, and the pelleted cells were subjected to total cell counting to evaluate the modeling effect of acute exacerbation of pulmonary fibrosis. Results Compared with the control group, varying degrees of damage were observed in the lung tissue of the model groups, among which the BLM (5 mg/kg) + LPS (2 mg/kg) group exhibited the most severe lung injury and pulmonary fibrosis. HE staining and Masson staining results showed that the alveolar structure was normal in the control group, with no inflammatory cell infiltration and only a small amount of collagen fiber deposition. In the BLM (5 mg/kg) + LPS (2 mg/kg) group, extensive destruction of alveolar structures, thickening and collapse of alveolar walls, widespread inflammatory cell infiltration, and massive collagen fiber deposition were observed. Compared with the BLM (4 mg/kg) + LPS (2 mg/kg) group and the BLM (5 mg/kg) + LPS (1 mg/kg) group, the lung tissue damage was the most severe. Cell counting results also showed that the total number of BALF cells in the BLM (5 mg/kg) + LPS (2 mg/kg) group was the highest among the three model groups, indicating the most pronounced inflammatory response in this group. Conclusions In this experiment, the combination of BLM and LPS can successfully construct a rat model of acute exacerbation of pulmonary fibrosis. The optimal dosage is BLM (5 mg/kg) + LPS (2 mg/kg).