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Objective:To explore the feasibility of chemical exchange saturation transfer (CEST) imaging at 3.0 T MRI in quantifying renal redox metabolism in vitro models and experimental animals.Methods:Redox metabolites in vitro models with physiological concentrations were prepared, including reduced metabolites (glutamate, alanine, glutathione) and oxidized metabolites (2-ketoglutarate, pyruvate, glutathione disulfide, ammonium hydroxide). CEST examinations were performed at 3.0 T MRI. The imaging parameters were as follows: CEST images with different saturation pulse intensity (B 1) (1, 2, 3, 4 μT) and a fixed radio frequency (RF) duration of 2 000 ms; CEST images with different RF durations (1 500 and 2 000 ms) were acquired with a fixed B 1 value of 2 μT to obtain the optimal scanning parameters. CEST examinations with optimized parameters were performed on the left kidneys of seven healthy rabbits, and the differences in magnetic resonance ratio asymmetry (MTR asym) between rabbit renal cortex and outer medulla were measured. A paired t-test was used to compare the differences. Results:The optimal B 1 for CEST examination of redox metabolites was 2 μT, and the optimal RF duration was 2 000 ms. The MTR asym peaks of glutathione disulfide, glutathione, glutamic acid, and alanine were at 3.75, 3.5, 3, and 1.5 ppm, respectively. The MTR asym peaks of pyruvate, 2-ketoglutarate, and ammonium hydroxide were at 1 ppm. The MTR asym peak values of reduced metabolites were higher than those of oxidized metabolites. When the B 1 value was 2 μT and the RF duration was 2 000 ms, the MTR asym signal of the renal cortex was (2.60±1.10) %, (2.86±1.32) %, (3.04±1.06) %, and (2.98±0.91) % at 1, 3, 3.5, and 3.75 ppm, respectively. The MTR asym signal of the outer medulla was (1.00±0.56) %, (2.43±0.94) %, (2.29±0.88) % and (1.98±0.58) %, respectively. The MTR asym signal of the renal cortex was higher than that of the outer medulla, and the differences were statistically significant ( t=3.04, P=0.023; t=2.56, P=0.043; t=3.50, P=0.013; t=3.45, P=0.014). Conclusion:CEST imaging at 3.0 T MRI can be used to quantitatively evaluate redox metabolism of healthy rabbit kidneys in vitro model and normal experimental rabbits.
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Objective@#To investigate the changes in mass spectrometry of proteins in patients with 1-bromopropane (1-BP) poisoning after treatment and their biological functions.@*Methods@#From May 2016 to December 2017, 3 male patients aged 31-47 years with 1-BP poisoning in Bao'an District of Shenzhen, China were enrolled in this study. The whole blood sample (2 ml) was collected before and after treatment. Label-free mass spectrometry-based proteomics was used for protein identification and quantification. The differentially expressed proteins after treatment were analyzed. Bioinformatics tools were used to analyze the functions of the identified proteins and the biological processes they were involved in.@*Results@#Proteomic analysis showed that there were 47 proteins that were differentially expressed more than 2-fold (P<0.05) after treatment in the patients with 1-BP poisoning; of them, 27 were up-regulated and 20 were down-regulated in the serum of treated patients. The identified proteins were mainly involved in proteolysis, protein modification, immune response, complement activation, lipoprotein metabolism, signal transduction, and coagulation.@*Conclusion@#The differentially expressed proteins after treatment can help with the diagnosis, treatment, and prognosis monitoring of 1-BP poisoning and provide potential therapeutic and prognostic markers for 1-BP poisoning treatment.
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Objective@#To investigate the current status and influencing factors of occupational stress among couriers.@*Methods@#Couriers (n=925) were selected on this study used cluster sampling method from January to March 2018. They were from SF and Zhongtong Express Co., Ltd., on the Wechat platform, and surveyed by a job stress questionnaire based on a job demand-control model.Valid questionnaires(n=617) were obtained.@*Results@#A total of 418 workers were occupational stress positive (67.7%). The results of Chi-square analysis showed that there were significant differences in occupational stress among workers categorized by job position, working years, mealtime, sleeping time, and weekly work time (P<0.05). The multivariate logistic analysis indicated that non-regular meals, short-term sleep and less than 0.5 working years were risk factors for occupational stress(P<0.05).@*Conclusion@#Couriers generally have occupational stress. The main influencing factors are job position, working years mealtime, sleeping time, and weekly work time. It is necessary to guide healthy lifestyle, rationally organize labor and assign tasks, and improve working environment to relieve their occupational stress.
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Objective@#This study focused on the proteomicchanges between workers exposed to methylbenzene (WMB) and healthy individuals (HI) .@*Methods@#The serum of WMB and HI was collected and the unmarked label free mass spectrometry was utilized for protein identification and quantitative comparison. The differentlyexpressed proteins in WMB and the HI were screened, followed by the analysis of protein and biological functions by bioinformatics tools.@*Results@#Thirty nine proteins were differently expressed between WMB and HI. Compared with HI, 24 proteins were up regulated and 15 proteins were down regulated over 2 fold change in WMB. Theseproteins were mainly involved in signal transduction, serine endopeptidase activity, inflammatory response, protein modification, stress reaction, coagulation reaction and so on.@*Conclusion@#The differently expressed proteins provide a potential protein marker for the health assessment of WMB and early diagnosis of methylbenzene poisioning and expand our understanding of the molecular mechanism of methylbenzene intoxication.
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<p><b>OBJECTIVE</b>To analyze the literature on power frequency electric field testing data and to propose views and suggestions for current testing.</p><p><b>METHODS</b>The literature on power frequency electric field testing data published in the previous years was searched to identify 306 articles involving 193 valid testing data. Mann-Whitney test and Wilcoxon W test were used for analyzing the testing data.</p><p><b>RESULTS</b>The classification of data was carried out according to one quarter of occupational exposure limit (1.25 kV/m), one half of the exposure limit (2.5 kV/m), and the exposure limit (5 kV/m). The structure of testing data showed a significant difference between the non-power facility group and the power facility group (P<0.05).</p><p><b>CONCLUSION</b>As occupational hazard factors, the radiation exposure from power frequency electric field is extensive. However, the power frequency electric field testing data in actual workplaces except high-voltage power facilities are far less than the occupational exposure limit with little harmfulness. There is a phenomenon of excessive testing at present.</p>
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Humanos , Eletricidade , Campos Eletromagnéticos , Exposição Ocupacional , Padrões de Referência , Local de TrabalhoRESUMO
<p><b>OBJECTIVE</b>To study the economic burden caused by occupational chronic n-hexane poisoning.</p><p><b>METHODS</b>Information about the cost of treatment, compensation, board, wage, diagnosis, escorts, transportation and the days off work were collected in a 34 cases of occupational chronic n-hexane poisoning accident to estimate the economic burden.</p><p><b>RESULTS</b>There were 4 mild, 19 moderate, 11 severe in the 34 cases and the total cost was 6 084 809 yuan. The hospitalization days was respectively (204.0 ± 3.7) d, (226.6 ± 78.3) d and (417.6 ± 94.1) d, averaging (285.8 ± 96.3) d. The treatment cost was respectively 62 525.8, 69 409.7 and 128 155.6 yuan. The compensation was respectively 20 000.0, 20 052.6 and 30 290.9 yuan. The wage was respectively 23 460.0, 26 062.6 and 47 644.0 yuan. The board was respectively 17 566.5, 19 499.8 and 36 230.1 yuan. The days of work was respectively (176.8 ± 3.2) d, (196.4 ± 67.9) d and (361.4 ± 81.6) d, averaging (247.7 ± 83.5). The lost productivity was respectively 1 809 724.8, 2 010 350.4 and 3 699 290.4 yuan.</p><p><b>CONCLUSION</b>The economic burden of occupational chronic n-hexane poisoning was so heavy that prevention measures should be strengthened.</p>