Male guinea pigs were exposed to 750ppm or l000ppm or 1 500ppm toluene (8h/d, for 14d), and their hearing thresholds were tested by means of Madsen ERA 2250 system 3d and 14d after exposure. Hearing impairment was observed in all groups. The degree of impairment was related to the exposure concentration and had a tendency to further damage in two weeks. The results indicate that toluene can cause acute hearing impairment even if its concentration is as low as 750ppm and the impairment develops from bad to worse at least in two weeks.

Objective To explore the mechanism of HIF-1α promoting malignant development of nasopharyngeal carcinoma by upregulating PD-L1 expression under hypoxic conditions. Methods CNE2 cells were divided into normoxia (20%O₂), hypoxia (1%O₂), HIF-1α-siRNA+hypoxia and NC-siRNA+hypoxia groups. Cell proliferation, apoptosis, the mRNA levels of HIF-1α, STAT3 and PD-L1, the protein levels of HIF-1α, PD-L1, STAT3 and STAT3 phosphorylation were detected by MTT assay, flow cytometry, RT-PCR and Western blot, respectively. Results Cell proliferation of hypoxia group was significantly higher than that of normoxia group (P=0.000). The cell proliferation rate of HIF-1α-siRNA+hypoxia group was significantly lower than those in other groups (P=0.000). The apoptosis rate of HIF-1α-siRNA+hypoxia group was remarkably higher than those in other groups (P=0.001). RT-PCR detection showed that the mRNA levels of HIF-1α, PD-L1 and STAT3 in the HIF-1α-siRNA+hypoxia group were significantly lower than those in hypoxia group and NC-siRNA+hypoxia group. The protein expression of HIF-1α, PD-L1 and STAT3 showed similar tendency in Western blot assays compared with the mRNA levels. The pSTAT3 protein expression level in HIF-1α-siRNA+hypoxia group was significantly lower than those in hypoxia group and HIF-1α-siRNA+hypoxia group (P=0.001). Conclusion Under hypoxic microenvironment, HIF-1α may up-regulate the expression of PD-L1 through STAT3, thereby promoting the immune escape of cancer cells, leading to the malignant development of nasopharyngeal carcinoma.

Objective To investigate the epidemiological features of out-of-hospital patients with ventricular fibrillation (VF) in Shanghai and to analysis factors associated with outcomes, and to provide evidence for improving the success rate of VF.Methods The data of patients with VF admitted to Shanghai Medical Emergency Center from January 2013 to December 2016 were analyzed retrospectively. All the data were recorded including the clinical data, medical service time, return of spontaneous circulation (ROSC) at scene/en route, survival to hospital discharge. Factors that associated with successful resuscitation were analyzed by Logistic regression.Results From 2013 to 2016, 21096 patients with suspected cardiac arrest were admitted to the Shanghai Medical Emergency Center. After excluding ventricular tachycardia (13 cases) and ventricular asystole (20995 cases), 88 patients with VF were enrolled, with 62 male and 26 female; the average age was (63.22±16.15) years old. While bystander cardiopulmonary resuscitation (CPR) was performed in only 21 cases (23.86％). Fifty-seven cases occurred during the day (08:00-20:00), while 31 cases occurred in the night. And the average emergency response time was (6.47±4.13) minutes; the average on-site time was (14.76±10.88) minutes; the average transport to hospital time was (5.95±4.00) minutes. There were no significant differences in response time, on-site time and transport to hospital time each year, and there were no significant differences in emergency medical service time between day and night either. From 2013 to 2016, prehospital successful resuscitation rate was decreased by years [95.65％ (22/23), 87.50％ (14/16), 83.33％ (20/24) vs. 80.00％(20/25), respectively,χ2 = 1.895,P = 0.595]. Survival to hospital discharge rate was increased by years [21.74％ (5/23), 31.25％ (5/16), 37.50％ (9/24), 40.00％ (10/25), respectively,χ2 = 2.862,P = 0.413]. The success rate of prehospital resuscitation for patients with 1, 2, ≥3 defibrillation was 35.23％ (31/88), 23.08％ (12/52), 89.19％ (33/37), respectively (χ2 = 42.811,P = 0.000). The on-site time in successful final resuscitation group was shorter than that in final resuscitation failure group (minutes: 10.85±8.83 vs. 16.79±11.36,t = 2.367,P = 0.020), the ROSC time in successful final resuscitation group was shorter than that of final resuscitation failure group (minutes: 3.24±3.17 vs. 7.43±6.64, t = 3.175,P = 0.002). It was shown by Logistic regression that long ROSC time was the risk factor for final resuscitation failure [odds ratio (OR) = 0.771,P = 0.024]. Gender, age, availability of witnesses CPR, call time, emergency response time, on-site time and transport to hospital time had no significant impact on the prehospital successful resuscitation and final successful resuscitation. In prehospital successful resuscitation group, there was significant difference in survival to hospital discharge rate among different defibrillation times group [48.39％ (15/31), 58.33％ (7/12) vs. 21.21％ (7/33),χ2 = 7.460,P = 0.024].Conclusions From 2013 to 2016, there were no significant changes in the emergency response time, prehospital successful resuscitation rate and survival to hospital discharge rate of patients with VF in Shanghai. Though, repeated defibrillation could significantly increased prehospital successful resuscitation rate, multiple defibrillation indicated decline of survival to hospital discharge rate in prehospital successful resuscitation group. Additionally, long on-site time and long ROSC time indicated poor prognosis.

Objective: To develop a new solid sorbent tube for capturing glycidyl methacrylate (GMA) in workplace air, and establish a complete set of method. Methods: GMA in workplace air was captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 50% (V/V) dimethylformamide-carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear range of GMA was 0.38-604.80 mg/L, and the related coefficient was 0.999 82. The within-run and the between-run precision were 1.11%-2.80% and 2.53%-4.84% respectively. The average desorption efficiency was 93.20%-94.97%. The minimum quantification concentration and The minimum quantification concentration were 0.02 and 0.07 mg/m³ respectively (3.00 L sample) . Samples could be stored for at least 8 days at room temperature. Conclusion The newly developed solid sorbent tube and its complete set of gas chromatography method is simple, and has high sensitivity and precision, so it can be used for sampling and quantitative detection of GMA in workplace air.

Objective:The aim of the study was to investigate the correlation between blood pressure response to cold pressor test (CPT) and follow-up blood pressure after 8 years in subjects, and to evaluate the predictive value of CPT for long-term blood pressure levels.Methods:A total of 365 individuals from eight natural villages were enrolled by stratified cluster sampling from Mei County, Shaanxi Province in 2004. Baseline characteristics of subjects were collected and CPTs were conducted. Subjects were followed up in 2009 and 2012, respectively. According to the maximal change of systolic response (SR), the area under the curve (AUC) of systolic blood pressure change (AUC-SBP), the maximal change of diastolic response (DR) and the AUC of diastolic blood pressure change (AUC-DBP) in CPT, the individuals were divided into four quartile groups by above parameters, respectively: group Ⅰ ( P25), group Ⅱ ( P50), group Ⅲ ( P75) and group Ⅳ ( P100). The correlation between blood pressure response to CPT and the follow-up blood pressure was analyzed. Results:(1) There were no significant differences in baseline blood pressure levels and prevalence of hypertension among four quartile groups no matter it was grouped on SR, DR, AUC-SBP or AUC-DBP. (2) The prevalence of hypertension in each group from lowest ( P25) to highest ( P100) in 2012 was 25.64%, 30.67%, 38.03%, 55.74% on SR grouping ( P<0.01), and 27.5%, 29.17%, 38.46%, 57.35% on AUC-SBP grouping ( P<0.05), respectively. (3) There were no significant differences in the prevalence of hypertension among four groups in 2012 ( P>0.05) either on DR or on AUC-DBP grouping. (4) The random effects model analysis showed that the correlation coefficient between SR, AUC-SBP and long-term systolic blood pressure increase were 1.91 ( P<0.05) and 1.44 ( P<0.05), respectively, and the correlation coefficient between DR, AUC-DBP and long-term diastolic blood pressure increase were 0.82 ( P<0.05) and 0.78 ( P>0.05), respectively. Age, male, body mass index, and fasting blood glucose were independent risk factors for long-term blood pressure elevation, and age, body mass index and fasting blood glucose positively correlated with changes in long-term blood pressure (all P<0.05). Conclusion:Individual systolic blood pressure response to CPT can be used as a predictor of long-term hypertension.

OBJECTIVE: To develop a solvent desorption-gas chromatography method for detecting ethylene glycol monopropyl ether( EGME) in workplace air. METHODS: EGME in workplace air was captured by charcoal tubes and desorbed by methanol-methylene chloride(5∶ 95,V/V),separated by capillary chromatographic column,and detected by flame ionization detector. RESULTS: The good linear range of EGME was 1. 37-1 913. 80 mg/L,and the correlation coefficient was 0. 999 90. The detection limit was 0. 06 mg/L. The minimum detectable concentration was 0. 02 mg/m3.The average desorption efficiency was 97. 81%-104. 70%. The within-run relative standard deviation( RSD) was 1. 94%-2. 99%,and the between-run RSD was 3. 24%-4. 53%. The samples could be stored at room temperature for at least 14 days. CONCLUSION: This method could be used for detection of EGME in workplace air.

Objective: To establish a solvent desorption-gas chromatography method for determination of dimethyl carbonate (DMC) in workplace air. Methods: The air samples were collected using activated carbon tubes, desorbed by carbon disulfide, separated by dimethylpolysiloxane capillary columns, and detected by a flame ionization detector. Results: The linear range of DMC was 2.14 to 1.07×10⁴ mg/L, and the correlation coefficient was greater than 0.999. The detection limit was 0.14 mg/L, the lower limit of quantification was 0.47 mg/L, the minimum detection concentration was 0.10 mg/m³, and the minimum quantification concentration was 0.32 mg/m³ (based on 1.5 L workplace air). The average desorption efficiency of the method was 96.2% to 102.0%. Both the within-run and between-run relative standard deviations were 0.9% to 2.3%. The samples could be stored for at least seven days at four celsius degree. Conclusion: This method shows high desorption efficiency, high sensitivity, good precision and is simple in using. It can be used for the determination of DMC in workplace air.

ObjectiveTo understand the monitoring result of occupational hazard in the workplace of key industries in Guangdong Province from 2020 to 2023. Methods The data of occupational hazards in the workplace of 20 key industries in Guangdong Province from 2020 to 2023 were collected from the “Workplace Occupational Hazard Monitoring System” of the Chinese Disease Prevention and Control System subsystem. The monitoring result of occupational hazard factors, occupational health training, occupational health examination, occupational protection, detection of occupational hazardous agents such as dust, chemical substances and noise were analyzed. Results A total of 13 058 enterprises from key industries were recruited as the monitoring subjects in Guangdong Province. There were 290 large-, 1 342 medium-, 7 635 small-, and 3 791 micro-enterprises, with small and micro-enterprises accounting for 58.5% and 29.0% of the total, respectively. A total of 7 542 enterprises exceeded the national standard in the detection of occupational hazards, with a rate of 57.8%. A total of 1 942 517 workers from 13 058 enterprises were recruited, with 835 567 workers were exposed to occupational hazards, with a rate of 43.0%. The rate of occupational health training for enterprise leaders, occupational health management personnel, and workers was 71.9%, 73.8%, and 86.5%, respectively. The abnormal rate of occupational health examinations for workers exposed to noise, dust, and chemical agents was 2.0%, 0.6%, and 1.0%, respectively. The distribution rate of dust masks, anti-poisoning masks or face masks, and noise prevention earplugs or earmuffs was 83.3%, 71.3%, and 77.8%, respectively. The rate of installation of dust prevention facilities, anti-poisoning facilities, and noise prevention facilities was 85.6%, 81.2%, and 50.1%, respectively. The rate of exceeded the national standard of dust, noise in the worksites/types and workplaces showed a decreasing trend year by year (all P<0.01), while the rate of exceeded the national standard of chemical agents in worksites/types and workplaces showed an increasing trend year by year in various occupational hazards (all P<0.01). Conclusion Occupational hazards in the workplace of key industries in Guangdong Province are relatively common. The proportion of workers exposed to occupational hazards is relatively high. It is necessary to further improve the use of noise prevention facilities and protective equipment, strengthen occupational health training for enterprises throughout the province and regularly monitor occupational hazards to reduce the risk of occupational diseases.

OBJECTIVE: To establish a solvent desorption-gas chromatography method for simultaneous determination of 2-methoxyethyl acetate(2-MEA) and 2-ethoxyethyl acetate(2-EEA) in the workplace air. METHODS: 2-MEA and 2-EEA in workplace air were captured by charcoal tubes and desorbed with solution of 5. 00%(V/V) methanol-methylene chloride,separated through capillary chromatographic column,and then analyzed by gas chromatography-flameionization detector. RESULTS: The linear ranges of 2-MEA and 2-EEA were 1. 50-2 403. 84 and 1. 79-2 871. 20 mg/L,respectively.The correlation coefficient were 0. 999 8. The minimum quantification concentrations were 0. 20 and 0. 09 mg/m~3,respectively(3. 00 L sample). The average desorption efficiencies were 98. 08%-99. 67% and 94. 34%-99. 79%,respectively. The within-run relative standard deviations(RSD) were 1. 77%-3. 51% and 1. 72%-3. 01%,respectively.The between-run RSD were 2. 27%-4. 44% and 2. 31%-4. 19%,respectively. The samples could be stored at room temperature for at least 14 days. CONCLUSION: This method could be used for simultaneous sampling and quantitative detection of 2-MEA and 2-EEA in workplace air.

OBJECTIVE: To establish a method for simultaneous determination of 1,1,1-trichloroethane(TCA) and 1,1,2-TCA in the workplace air by solvent desorption-gas chromatography. METHODS: The 1,1,1-TCA and 1,1,2-TCA in the workplace air were collected by activated carbon tube and desorbed with carbon disulfide. They were separated with DB-1(100.0% dimethyl polysiloxane) capillary column and detected by flame ionization detector. RESULTS: The good linear ranges of 1,1,1-TCA and 1,1,2-TCA were 1.340-1.338×10~4 and 1.440-1.442×10~4 mg/L, respectively. The correlation coefficients were greater than 0.999, with the detection limits of 0.100 and 0.140 mg/L, respectively. The average desorption efficiencies of 1,1,1-TCA and 1,1,2-TCA were 98.6%-99.6% and 94.9%-96.2%. The within-run and between-run relative standard deviations were 0.4%-0.9% and 0.5%-1.1%, respectively. The samples could be stored at room temperature for at least 14 days. CONCLUSION: This method has high desorption efficiency and sensitivity, good precision and simple operation, which is suitable for simultaneous detection of 1,1,1-TCA and 1,1,2-TCA in the workplace air.