[Incidence and risk factors of acute mountain sickness in grid construction personnel working at plateau]

Objective: To analyze the incidence and risk factors of acute mountain sickness (AMS) in grid construction personnel working at plateau. Methods: A total of 10 956 plateau construction personnel of Ali Network Project from January 1, 2019 to December 31, 2020 were included. Baseline information (including age, sex, body mass index, developmental and nutritional status, relevant clinical indicators, etc.) and follow-up data of AMS were obtained from the medical record of Ali Internet engineering staff medical station. The altitude of the residence place in early life and the working environment were obtained from the website (https://zh-cn.topographic-map.com/legal/). The incidences of overall AMS and its subgroups were calculated, and the Cox proportional hazards model was used to explore the risk factors for AMS. Results: The age of the participants was (36.1±10.5) years old at baseline, and 95.27% (10 438) of them were males. The follow-up time was (17.46±4.23) months. The altitude of the residence place in early-life and working environment were (1 959±937) m and (4 533±233) m, respectively. During the follow-up period, the incidence of AMS was 15.58% (1 707 cases), and the incidence for acute mountain sickness and high altitude pulmonary edema were 15.53% (1 702 cases) and 0.05% (5 cases), respectively. No high altitude cerebral edema patients were found. Cox proportional hazards model showed that the risk of AMS increased by 45% for every 100 m elevation in the altitude of working environment [HR (95%CI): 1.45 (1.41-1.51)]. The higher the altitude for the residence place in early-life, the lower the risk of AMS [HR (95%CI): 0.84 (0.80-0.88)]. Compared with the group with oxygen saturation during 90%-94%, the participants with oxygen saturation<75% [HR (95%CI): 1.67 (1.24-2.23)] at baseline was also associated with increased risk of AMS. Conclusions: The incidence of AMS is relatively low in grid construction workers working on plateau. The risk factors of AMS included higher working altitude, lower altitude of the residence place in early-life and oxygen saturation<75%.

[Investigation and analysis of occupational hazards in construction of power transmission and transformation project]

Objective: To investigate the occupational hazard factors and exposure levels of workers during the construction of power transmission and transformation projects. Methods: Analysis and identification of occupational hazard factors were carried out for typical construction process of 6 power transmission projects and 3 substation projects in September 2018. The on-site occupational health investigation was carried out to detect and analyze the exposure levels of workers to occupational hazard factors. Results: The time weighted average concentration (C(TWA)) of crushing workers exposed to silica dust and welders exposed to welding fume in substation projects were 2.72 and 14.03 mg/m(3), respectively. The 8 h equivalent sound level results of exposure noise of carpenters in power transmission projects and crushing workers, reinforcement workers, carpenters, scaffolders, road builders in substation projects were 87.9, 92.5, 87.1, 92.5, 93.0 and 90.2 dB (A) , respectively. The 4-hour time equal energy frequency weighted vibration acceleration of hand-transmitted vibration of bricklayer in power transmission projects, bricklayer, general worker 3, road builder 1 and road builder 2 of substation projects were 5.36, 5.21, 5.28, 10.71 and 5.22 m/s(2), respectively. The effective irradiance of electric welding arc light of welders' limbs in power transmission projects and substation projects were 401.19, 319.68 μW/cm(2), respectively. All of the above exceeded the requirements of occupational exposure limits. The occupational radiation levels and exposure limits of hazardous chemical factors met the requirements of each post. Conclusion: During the construction of power transmission and transformation projects, the exposure levels of occupational hazard factors in multiple posts exceed the standard. The main responsibility of employers for occupational disease prevention and control should be implemented, and targeted comprehensive measures should be taken to reduce the exposure levels of occupational hazard factors of workers.

Functional recognition of the neuronal tyrosine hydroxylase cAMP regulatory element in different cell types

Transient transfection of pLB2CAT constructs bearing short synthetic oligonucleotides derived either from the tyrosine hydroxylase (TH) promoter or other sources was used to examine functional cAMP regulatory element (CRE) activity in a variety of cell lines. The region containing only the putative TH CRE was found to be as or more effective in conferring cAMP responsiveness onto pLB2CAT (which employs the TK promoter) than the immediate 272 bp region of the TH promoter. Increases in CAT activity of 10- to 20-fold were observed in JEG-3 cells with a single insert of the TH CRE region (-31 to -54) in pLB2CAT, and the presence of a second insert generated only a modest further increase. This construct also responded to cAMP in 4 other cell lines tested but the degree of increase was less dramatic. Inserts containing the consensus 8 bp CRE motif embedded in other natural or artificial contexts served generally as weak functional CREs in all cell lines tested. In vitro analysis revealed that a specific protein-DNA complex apparently containing a single protein with a MW of 45-50 kDa was formed equally well with JEG-3 cell nuclear extract and CRE-bearing-TH and other fragments which produced dramatically different cAMP effects in vivo. These results suggest specificity in the effects of cAMP on different CREs which are dictated by contextual differences.