Objective: To explore the correlation between blind box consumption and non-suicidal self-injury(NSSI) among middle school students, so as to provide new theoretical insights for the prevention of NSSI. Methods: Using stratified random cluster sampling method, 2 807 middle school students aged 11-19 years old were selected from Hunan and Gansu provinces from November 2024 to March 2025. The blind box consumption questionnaire and Functional Assessment of Self mutilation Scale were administered to collect data on students blind box consumption frequency, as well as NSSI behavior. The χ 2 test was used to compare differences in the distribution of NSSI across different groups. Multivariate Logistic regression analysis was performed to infer the correlation and gender differences. Results: A total of 15.3% of middle school students reported having at least one NSSI incident in the past year, among which the reported rates of occasional NSSI (1-4 times) and repeated NSSI (≥5 times) were 5.5% and 9.8% respectively. The results of univariate analysis showed that there was statistically significant different in NSSI distribution among groups with different blind box consumption frequencies ( χ 2=55.72, P <0.05). After adjusting for confounding factors such as age, gender, school stage, family type, discipline style, pocket money, impulsiveness and emotion management, the results of multiple Logistic regression models showed that compared with the group without blind box consumption, the risks of "occasional NSSI" and "repeated NSSI" were higher in the group with blind box consumption ( OR =1.54, 1.66), and the frequency of blind box consumption(continous variable) was positively correlated with the risks of "occasional NSSI" and "repeated NSSI" among middle school students ( OR =1.26, 1.34)(all P <0.05).After gender stratification, the consumption behavior of blind boxes and the frequency of blind box consumption (continuous variable) of boys and girls were associated with "repeated NSSI"(boys: OR =1.61, 1.32, girls: OR =1.65, 1.35), and only in the male group was a correlation between blind box consumption and "occasional NSSI" observed ( OR =2.27) (all P <0.05). Conclusion Blind box consumption may be related to NSSI among middle school students, and there are gender differences in its correlation with NSSI among middle school students.

Objective:To explore the relationship between respiratory mechanics and right heart function during ARDS mechanical ventilation through the establishment of Beagle dogs acute respiratory distress syndrome (ARDS) animal model and the application of different levels of mechanical ventilation, which will provide theoretical basis for right heart protective ventilation strategy of ARDS.Methods:Beagle dogs were anesthetized successfully and then pulmonary artery floating catheter, esophageal manometric catheter and femoral artery catheter were inserted. Under the pressure control mode, the driving pressure was fixed. After adjustment, PEEP gradually increased from 2 cmH 2O to 14 cmH 2O. The changes of respiratory mechanics, hemodynamics and right heart function were observed. ARDS model was established by injecting oleic acid into central vein, and mechanical ventilation with the same parameters was given after the model was established successfully. In contrast to itself, the changes of respiratory mechanics, hemodynamics and right heart function indexes of experimental dogs before and after modeling were analyzed. In the group, the indexes of different PEEP were compared by ANOVA, and then compared by Student-Newman-Keuls. The difference was statistically significant at a P value <0.05. Results:Before modeling, the peak airway pressure (P peak) and plateau pressure (P plat) increased with the increase of PEEP ( F=232.733,196.33, P<0.05). However, P trans-I, P trans-E, C stat and Vt decreased significantly ( F=4.524, 6.499, 64.803, 2.31, P<0.05). The area of change of right ventricle (FAC) became smaller ( F=3.09, P<0.05); SV first increased and then decreased ( F=3.24, P<0.05), and CVP and MPAP increased ( F=19.07,14.81, P<0.05). There was no significant difference in TAPSE, MAP, HR and SpO 2 ( P>0.05). After modeling, as PEEP increased, P peak, P plat, P ES-I and P ES-E increased significantly ( F=24.829, 41.95, 9.78, 87.86, P<0.05). Vt, P trans-I, P trans-E, C stat and Vt first increased and then decreased ( F=2.91, 4.29, 5.84, 48.890, P<0.05). TAPSE and SV first increased and then decreased ( F=6.22,6.54, P<0.05). CVP and MPAP increased ( F=5.23, 19.24, P<0.05). MAP increased first and then decreased ( F=5.02, P<0.05). SpO 2 increased ( F=2.77, P<0.05). FAC and HR had no statistical significance ( P>0.05). Conclusions:Trans pulmonary pressure and lung compliance can reflect the effectiveness of ARDS lung recruitment, and have good synergy; with the increase of PEEP, the right ventricular systolic function TAPSE is first affected, and SV compensatory increase, but with the increase of PEEP, TAPSE and SV decrease; pulmonary blood flow distribution is more important in improving alveolar oxygenation. Therefore, real-time monitoring of trans pulmonary pressure, TAPSE and intrapulmonary blood flow should be performed in ARDS treatment.

OBJECTIVE: To establish a method for determination of N-methyl-2-pyrrolidone(NMP) in workplace air by solvent desorption-gas chromatography. METHODS: NMP in the workplace air was collected with activated carbon tube and desorbed with methanol ∶dichloromethane(5 ∶95, V/V). After desorption, it was separated by capillary column separation, and detected by flame ionization detector. RESULTS: The good linear concentration of NMP was 0.51-4 108.00 mg/L. The correlation coefficient was 0.999 9. The detection limit was 0.08 mg/L(calculated by 3 times of standard deviation). The average desorption efficiency was 101.68%-103.44%. The within-run and between-run relative standard deviations were 1.94%-3.97% and 0.97%-2.26%, respectively. The sample could be stored at room temperature for at least 14 days. CONCLUSION: The developed method is suitable for the determination of NMP in workplace air.