Objective To investigate the effect of subchronic inhalation of toluene diisocyanate (TDI) on oxidative stress damage in rat lung tissue. Methods SPF-grade Sprague-Dawley male rats were randomly divided into 4 groups,the rats were placed in a HOPE-MED 8050A movable poison cabinet in a cage.To observe the ultrastructural and histopathology changes of lung tissue in rats.The levels of reduced glutathione (GSH), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in lung tissue were detected. The ultrastructural and histopathological changes were examined. The expression levels of HO-1 mRNA and protein were detected by Real-time PCR and Western Blot, respectively. Results The body mass, lung tissue mass, and lung organ coefficient of rats in each dose group were lower than those in the control group (P<0.05), and the body mass of rats in each group increased with the increase of exposure time (P<0.05); The results of lung histopathological examination showed that after TDI exposure,in the high-dose group, pulmonary alveolar wall hyperemia and edema were observed in the lung tissue of rats, alveolar wall thickening was observed, alveolar septa widening, and a large number of red blood cells were seen in the alveolar cavity. The results of ultrastructural examination of lung tissue showed that after TDI exposure, while in the high-dose group, the number of alveolar cells decreased, with unclear cell boundaries and irregular morphology. The levels of MDA in the lung tissue of rats exposed to TDI at various doses were higher than those in the control group (P<0.05), while the levels of GSH, GSH-Px, SOD, and CAT were lower than those in the control group (P<0.05); There was no significant difference in HO-1 gene and protein levels among rats in each group (P>0.05). Conclusion Subchronic inhalation of TDI can cause changes in the pathology and ultrastructure of rat lung tissue, leading to abnormal levels of metabolic enzymes in lung function, thereby inducing oxidative stress damage to the lungs. However, but HO-1 is involved in oxidative stress damage in the lungs induced by TDI.

Objective To analyze the applicability of different risk assessment methods in assessing laboratory benzenes exposure. Methods The work positions exposed to benzenes (benzene, toluene, xylenes) of a chemical catalyst research and development company were selected as the research subjects. An occupational health field survey was conducted, and the benzenes exposure levels of the lab personnel were measured. Qualitative assessment method, comprehensive index method, quantitative assessment method, and occupational hazards classification method were used to evaluate the occupational health risk on benzenes exposure in the laboratory personnel. The applicability of different assessment methods was compared. Results The occupational health engineering protection measures and management system of the company need to be further implemented. The benzene exposure level of benzene hydrogenation laboratory personnel exceeded the national standard, with the exposure concentration of time weighted average (C_TWA) of 5.00 mg/m³ and short term exposure concentration (C_STE) of 10.50 mg/m³. The C_TWA and C_STE of toluene and xylenes exposure were both lower than the minimum quantitative concentrations. The results of different risk assessment methods varied. The qualitative assessment method indicated higher level of occupational health risk of benzenes, while the comprehensive index and hazard classification methods indicated consistent result on lower level of benzenes. For occupational health risk of benzene, the standardized risk ratio (RR) levels corresponding to the qualitative and quantitative assessment methods were both extremely high risk. The RR levels of benzene exposure assessment using the comprehensive index method and the occupational hazards classification method were high, while the corresponding RR levels of exposure to toluene and xylenes were both low. Conclusion Attention should be paid on the health risks of benzene exposure to benzene hydrogenation laboratory personnel. When benzene exposure level is below the national occupational exposure limit, occupational hazards classification method is not recommended for health risk assessment for benzenes. The comprehensive index method is preferable when more comprehensive occupational health information is available, as it provides a more objective and comprehensive evaluation on occupational health risks of benzenes.

Objective To construct a Cox proportional hazards prediction model for secondary intracranial hypertension in patients with acute subdural hematoma (ASDH) during the perioperative period and validate its effectiveness. Methods Clinical data of 78 patients with ASDH were retrospectively collected and divided into secondary group (25 cases with secondary intracranial hypertension during perioperation) and control group (53 cases without secondary intracranial hypertension during perioperation). Differences in demographic indicators, comorbidities, clinical biochemical indicators, and imaging data between the two groups were compared. The Cox proportional hazards model was used to perform a multivariate analysis of independent risk factors that may affect secondary intracranial hypertension in ASDH patients during the perioperative period. A prediction model for secondary intracranial hypertension in ASDH patients during the perioperative period was established, and Harrell′s C index was calculated to assess the predictive accuracy of the model. The degree of agreement between the model prediction and actual risks was evaluated through a nomogram and calibration curve. Results The six-month follow-up rate was 89.74% (70/78). Age, smoking history, hypertension, diabetes, preoperative Glasgow Coma Scale (GCS) score, Glasgow Outcome Scale (GOS) score, complex hematoma, intracranial hematoma volume, mean arterial pressure, glycated hemoglobin (HbA1c), international normalized ratio (INR), interleukin-6 (IL-6), and procalcitonin (PCT) in the secondary group showed statistically significant differences compared with the control group (P < 0.05). Age(OR=2.895; 95%CI, 1.264 to 6.633; P=0.022), smoking history (OR=2.146; 95%CI, 1.029 to 4.475; P=0.036), GOS score (OR=0.288; 95%CI, 0.112 to 0.741; P=0.015), HbA1c (OR=3.325; 95%CI, 1.243 to 8.894; P=0.028), INR (OR=2.746; 95%CI, 1.203 to 6.267; P=0.027), and PCT (OR=3.426; 95%CI, 1.335 to 8.795; P=0.019) were independent influencing factors for secondary intracranial hypertension in ASDH patients during the perioperative period. Harrell′s C index was 0.812 (95%CI, 0.789 to 0.872). The nomogram and calibration curve showed good consistency between the actual risk and the model prediction. Conclusion Cox proportional hazards model for patients with acute subdural hematoma has high accuracy in predicting the risk of secondary intracranial hypertension during the perioperative period and is suitable for clinical promotion.

Objective To understand the occupational health status of gas station workers, to analyze the characteristics of early health damage, and to provide a reference for the occupational health monitoring of workers in this industry. Methods The gas station workers who underwent occupational health examination in an occupational health examination institution in Tianjin in 2021were selected as the research subjects. The examination results were statistically analyzed. Results A total of 381 gas station workers were included in this study, with a sex ratio of male to female of 1.40:1. The top three tests with abnormal results from high to low were abdominal color Doppler ultrasound (39.63%), urine routine (29.13%), and blood pressure (23.62%). The detected fatty liver accounted for 74.83% of abnormal abdominal color Doppler ultrasound. Analysis of abnormal results of different genders showed that the detection rate of abnormal blood pressure, fatty liver and liver function in males was higher than that in females (χ²=16.40, 25.40, 15.98，P＜0.05), the detection rate of high GGT in males was significantly higher than that in females (χ²=16.04，P＜0.05）. The detection rate of abnormal urine routine in females was higher than that in males (χ²=12.85，P＜0.05), and the positive rate of urine white blood cells and blood in urine were significantly higher I women than those in men (χ² =16.80, 11.66，P＜0.05). The abnormal detection rate of electrocardiogram of gas station workers increased with age (χ²=28.02，P＜0.05), and the abnormality of high blood pressure showed an increasing trend with age and working years（χ²=25.00, 15.26，P＜0.05). Conclusion The long-term exposure of gas station workers to chemical toxic substances such as organic solvents and benzene series and physical factors such as high temperature in summer and low temperature in winter will have a certain impact on health. It is suggested that employers should reasonably arrange their work systems and carry out occupational health monitoring in a targeted manner.

Objective To analyze the diagnosis cases of occupational benzene poisoning in gas station industry, and to explore the application of GC-MS technology in occupational disease diagnosis.   Methods The epidemiological method was used to describe and analyze the occupational disease diagnosis of 15 gas station workers , and qualitative screening of occupational hazard factors was performed by GC-MS.   Results All the 15 workers had more than one year's occupation history of oil refueling and unloading.  The clinical manifestations were consistent with the characteristics of chronic benzene poisoning in diagnosis of occupational benzene poisoning.  However, due to lack of evidence of occupational exposure to benzene and incomplete diagnostic data, occupational chronic benzene poisoning was not diagnosed. GC-MS technology was used to screen the occupational hazard factors in the gas station workplace, and benzene, n-pentane, n-hexane and so on were found.  Conclusion GC-MS is recommended for qualitative screening of organic solvents such as benzene when diagnosing occupational diseases for gas station workers , so as to accurately identify occupational hazard factors in workplaces and provide reliable basis for diagnosis of occupational diseases.

Objective To understand the occurrence characteristics of occupational chemical incidents in China by media surveillance, to provide scientific evidences for formulating effective prevention and control strategies, and to provide new ideas for public surveillance and early warning of chemical incidents. Methods Occupational chemical incidents were collected and sorted through the Internet every day. The statistical analysis was conducted from time, region, industry, and causes of the collected incidents. Results A total of 99 occupational chemical incidents were collected in 2021, involving 356 peoples and 186 deaths. April to July was the high incidence period of events, mainly limited space poisoning and asphyxiation events. Majority of the incidents were general grade events, mainly occurring in small and medium enterprises. Guangdong Province had the most incident reporting areas. Incidents mainly occurred in chemical raw material and chemical product manufacturing industry as well as in water production and supply industry, mainly in manufacturing, cleaning and maintenance positions. The main types of poisons were asphyxiating gases and organic solvents, mainly involving hydrogen sulfide and benzene. The incidents could have been caused by lack of safety awareness, leakage of equipment, and lack of protective measures. Conclusion Occupational chemical incidents still occur frequently and cause serious harm. It is suggested that the relevant departments and employers should strengthen supervision and management, effectively manage and control operational risks, and increase supervision of key industries and positions, to ensure the health and safety of workers.

ObjectiveTo explore the mental health status and its influencing factors among middle school students in Xide County， Liangshan Yi Autonomous Prefecture， and to provide references for mental health interventions for local middle school students. MethodsUsing a cross-sectional study design， one junior middle school and one senior middle school in Xide County， Liangshan Prefecture， Sichuan Province， were randomly selected on September 16， 2021， and two classes per grade in each school involving 288 students were recruited. Subjects were assessed using Patients' Health Questionnaire Depression Scale-9 item （PHQ-9）， Generalized Anxiety Disorder Scale-7 item （GAD-7）， PTSD Checklist for DSM-5 （PCL-5）， Multidimensional Scale of Perceived Social Support （MSPSS） and UCLA Loneliness Scale （ULS-3）. Then the scores of above scales were compared among middle school students with different demographic characteristics， and binary Logistic regression analysis was conducted to screen the influencing factors of post-traumatic stress disorder (PTSD） symptoms. ResultsAmong the respondents， 17.71% （95% CI： 0.133~0.221）， 8.68% （95% CI： 0.054~0.120）， 2.78% （95% CI： 0.009~0.047） and 45.83% （95% CI： 0.400~0.516） were reported to have symptoms of depression， anxiety， PTSD and loneliness， respectively. Students in senior middle school scored lower on PCL-5 and ULS-3 than those in junior middle school ［（6.46±8.91） vs. （8.87±9.42）， t=2.202， P<0.05； （4.67±1.65） vs. （5.60±1.88）， t=4.431， P<0.01］. Regression analysis denoted that depressive symptoms （OR=7.630， P<0.05） and anxiety symptoms （OR=3.789， P<0.01） were risk factors for PTSD symptoms among middle school students. ConclusionThe middle school students in Xide County， Liangshan Yi Autonomous Prefecture suffer a high prevalence rate of depressive symptoms and loneliness， and those in junior middle school are more likely to feel a sense of strong loneliness， furthermore， depressive symptoms and anxiety symptoms are risk factors for PTSD symptoms.

Objective:To investigate the application value of joint friction sounds in diagnosing meniscus injury of the knee based on machine learning models.Methods:A case-control study was conducted to analyze the clinical data of 17 patients with meniscus injury of the knee (meniscus injury group) admitted to Sir Run Run Shaw Hospital Affiliated to Nanjing Medical University from August 2020 to October 2022, as well as 75 recruited healthy subjects without knee joint diseases (healthy group). The knee joint friction sounds of the subjects were collected in a relatively quiet environment (peak value below 40 dB). The sounds collected in a flexion-extension-flexion mode of exercise were split and divided randomly with a ratio of 4∶1 into the training set (125 segments from the meniscal injury group and 187 segments from the healthy group) and the test set (33 segments from the meniscal injury group and 47 segments from the healthy group). The sounds obtained in a sit-stand-sit mode of exercise were split and divided randomly with a ratio of 4∶1 into the training set (81 segments from the meniscal injury group and 164 segments from the healthy group) and the test set (20 segments from the meniscal injury group and 40 segments from the healthy group). Four machine learning models were built, including support vector machine with linear kernels, radial basis function support vector machine, random forest, and extremely randomized trees. The learning training of the model was performed on the training set, and its model performance was verified with the test set. The time required in a single collection of joint friction sound from the subjects and the interpretation of data analysis was recorded. Knee function of the subjects were scored according to the Lysholm Score before and at 1 day after the test. The accuracy rates of diagnosis of meniscus injury with friction sounds under the two modes of exercise were compared based on the test results to yield an optimal one. The effectiveness of the four models was compared to find the best machine learning model fitting the data frame of this study according to the test results such as accuracy, sensitivity, specificity, F1 score, and area under the receiver operating characteristic curve (AUC) obtained with the optimal mode of exercise. The diagnostic accuracy, misdiagnosis rate and missed diagnosis rate of joint friction sound for meniscal injury under the optimal machine learning model with the optimal mode of exercise were observed.Results:The time required in a single collection of joint friction sound ranged from 5 to 10 minutes [(7.1±1.3)minutes], when the time required for interpretation of data analysis was approximately 1 minute. The Lysholm Score before and after the test was (75.6±4.0)points and (77.7±3.7)points respectively in the meniscal injury group ( P>0.05), and (99.6±0.9)points and (99.5±1.0)points respectively in the healthy group ( P>0.05). The diagnosing accuracy rates for flexion-extension-flexion of exercise and sit-stand-sit modes of exercise were 0.775 and 0.817 under the support vector machine model with linear kernels; 0.813 and 0.900 under the radial basis function support vector machine model; 0.800 and 0.867 under the random forest model; 0.800 and 0.900 under the extremely randomized tree model. The accuracy rates for sit-stand-sit mode of exercise were all higher than those for flexion-extension-flexion mode of exercise. In the sit-stand-sit mode of exercise, the extremely randomized tree model had an accuracy rate of 0.900, sensitivity of 0.900, specificity of 0.950, F1 score of 0.900, and AUC of 0.942, which were higher than those under the remaining 3 models, showing better machine learning efficacy. Under the extremely randomized tree model in the sit-stand-sit mode of exercise, 22 (18 true positive and 4 false positive) were diagnosed as meniscal injury and 38 (36 true negative and 2 false negative) as healthy out of 60 segments in the test set (20 from the meniscal injury group and 40 from the healthy group). The diagnostic accuracy of joint friction sounds in diagnosing meniscus injury of the knee was 0.900, with the misdiagnosis rate of 0.100 and the missed diagnosis rate of 0.100. Conclusion:Diagnosis of meniscus injury of the knee with joint friction sounds can shorten time and enhance safety during the examination process. The diagnostic model using machine learning-based artificial intelligence is faster and more stable, which can be used as a diagnostic marker for such injury.

Objective To investigate the effect of subchronic inhalation of toluene diisocyanate (TDI) on the pathological changes, oxidative stress damage, and HO-1 expression levels in rat liver tissues. Methods Forty healthy 3-week-old SPF-grade Sprague-Dawley male rats were randomly divided into 4 groups (control group, low-dose group, medium-dose group, and high-dose group), each with 10 rats. The rats were placed in a HOPE-MED 8050A movable poison cabinet in a cage. TDI was administered to animals by inhalation at doses of 0, 3.06 mg/m³, 12.25 mg/m³, and 49.00 mg/m³, respectively, for 6 hours a day and 5 days a week, and continuously for 13 weeks. The control group was exposed to fresh air. The effect of TDI on pathological changes, oxidative stress damage and HO-1 expression in rat liver tissues was examined. Results Compared with the control group, the rats in the medium and high-dose TDI-exposed groups exhibited vacuolar changes, hepatocyte swelling, steatosis and other pathological changes. With the increase of the TDI dose, the gap between hepatocytes was widened, mitochondria were swollen and vacuolated, and mitochondrial cristae disappeared. The expression levels of HO-1 gene and protein in the liver tissues of the low, medium, and high dose groups were significantly higher than those in the control group (P<0.05). Compared with the control group, the number of HO-1 positive cells in the low, medium and high dose groups increased and the staining increased gradually, and the difference was statistically significant (P<0.05). Conclusion TDI exposure can cause oxidative damage to rat liver tissues and induce the expression levels of HO-1 gene and protein expression.

Objective: To investigate the cause of an incident of occupational contact dermatitis in a farm in Tianjin Prefecture, so as to provide insights into occupational safety. Methods: The disinfection process, use of disinfectants and individual protective measures in this farm were collected, and a field epidemiological investigation was conducted to collect the demographic characteristics, history of occupational contact, clinical symptoms, diagnosis and treatment data, and onset of disease among individuals with the same type of job. The cause of this incident was analyzed. Results: There were ten interns exposed to potassium hydrogen sulfate compounds simultaneously in this farm, and then, nine interns developed skin flushing across the body, and swelling and itching of the skin. Among these ten interns, five individuals were admitted to hospitals because of severe symptoms and were then clinically diagnosed as systemic contact dermatitis. All five individuals were cured following treatments. Epidemiological survey showed that all cases had a definite history of occupational contact with potassium hydrogen sulfate compounds but without use of any protective agents. In addition, there were thirty-five individuals with the same type of job in this farm that developed similar symptoms when they joined in the disinfection for the first time, and these individuals were self-cured following cessation to contact; however, recurrence of symptoms was found following contacts again. Conclusion This is a cluster of occupational contact dermatitis caused by exposure to potassium hydrogen sulfate compound.