Objective:To conduct an occupational hygiene investigation and simulated sampling and testing on welding positions in a company in a certain province, and to perform a simulated analysis of the concentration of occupational hazard factors in workers suspected of occupational asthma.Methods:In November 2023, the investigation and analysis of workers' exposure to occupational hazard factors were carried out through occupational hygiene surveys, laboratory simulated sampling and testing, and a combination of qualitative and quantitative detection methods.Results:Toluene diisocyanate (TDI) was present in the workplace air of the employer. TDI was detected in the raw materials provided by the workers. Laboratory simulations of the production process and working conditions at the position were conducted with sampling at different distances, revealing a maximum TDI concentration of 0.49 mg/m 3 and a minimum concentration of 0.01 mg/m 3. The results showed that the closer the sampling distance was to the breathing zone, the more significantly the TDI concentration increased. The laboratory simulated sampling and testing results were highly consistent with the on-site sampling and testing results from a testing agency in Beijing. Conclusion:The occupational hazard factor TDI is present in the workers' workplace, and TDI may be the cause of the suspected occupational asthma in the workers.

Objective:To conduct an occupational hygiene investigation and simulated sampling and testing on welding positions in a company in a certain province, and to perform a simulated analysis of the concentration of occupational hazard factors in workers suspected of occupational asthma.Methods:In November 2023, the investigation and analysis of workers' exposure to occupational hazard factors were carried out through occupational hygiene surveys, laboratory simulated sampling and testing, and a combination of qualitative and quantitative detection methods.Results:Toluene diisocyanate (TDI) was present in the workplace air of the employer. TDI was detected in the raw materials provided by the workers. Laboratory simulations of the production process and working conditions at the position were conducted with sampling at different distances, revealing a maximum TDI concentration of 0.49 mg/m 3 and a minimum concentration of 0.01 mg/m 3. The results showed that the closer the sampling distance was to the breathing zone, the more significantly the TDI concentration increased. The laboratory simulated sampling and testing results were highly consistent with the on-site sampling and testing results from a testing agency in Beijing. Conclusion:The occupational hazard factor TDI is present in the workers' workplace, and TDI may be the cause of the suspected occupational asthma in the workers.

Objective To investigate the feasibility of amplitude of intraoperative nerve action potentials (NAP) for early quantitative diagnosis of peripheral nerve injury. Methods The sciatic nerve injury model were established in 16 rabbits. Intraoperative NAP were recorded after 4 weeks. According to amplitude of NAP, the injuried nerve were divided into 3 groups: NAP ＜ 100 μV in A group, 100 μV ≤NAP ＜ 500 μV in B group, NAP ≥ 500 μV in C group. Nerve specimen 1cm distal to injuried point were resected that received glycine silver stain and image analysis including number, diameter and cross section area of regenerative axons. Footprint parameter and ulcer area were measured and contrasted between each two groups. Results The number, diameter and cross section area of A group regenerative axons have significant difference with B and C group, no significant difference between B and C group; Footprint parameter and ulcer area have significant difference in each two groups. Conclusion Amplitude of intraoperative NAP can be a quantitative criteria to diagnose the degree of peripheral nerve injury that provides experiment evidence for guide intraoperative decision-making in clinical practice.