Establishment of a nomogram for predicting the high frequency hearing loss of workers exposed to noise / 中华劳动卫生职业病杂志

Objective@#To explore the related influencing factors of high frequency hearing loss (HFHL) in workers exposed to noise and establish a prediction nomogram for HFHL.@*Methods@#A total of 822 workers exposed to noise from 46 enterprises were included. A questionnaire survey and a pure-tone hearing test were conducted for the workers. The data of noise level of the workers exposed was also collected. After single factor analysis of related influencing factors, the multivariate Logistic regression analysis was performed to identify the final independent influencing factors of HFHL. Finally, a nomogram model was established by R software to achieve individual prediction of HFHL.@*Results@#Among the 822 workers exposed to noise, 166 (20.2%) workers had HFHL. In multivariate Logistic regression analysis, increasing age, men, increasing wearing earphone time, less wearing earplugs, and high noise level were the independent risk factors for HFHL. The C-index of the nomogram model for predicting HFHL was 0.834 (95%CI: 0.748~0.903) . The area under the predictive power curve of nomogram model was 0.834 (95%CI: 0.799~0.869, P<0.001) .@*Conclusion@#Age, sex, wearing earphone time, wearing earplugs, and noise level are independent influence factors for HFHL. The nomogram model is successfully established as a accurate and visible tool for individually predicting the HFHL risk in workers exposed to noise.

Constitutive display of Candida antarctica lipase B on the cell surface of Aspergillus niger and regulation of its fermentation / 生物工程学报

Displaying Candida antarctica lipase B (CALB) on the cell surface of Aspergillus niger is effectively applied for the industries of food, cosmetics, pharmaceutical and so on. Displaying CALB using induced promoter of glucoamylase on the cell surface of A. niger SH-1 has some problems such as inhibiting its expression under high concentration of glucose, mycelium cleavage and decreasing enzyme activity in the later period of fermentation process. Displaying CALB manipulated by constitutive promoter from glyceraldehyde-3-phosphate dehydrogenase instead of glucoamylase on the cell surface of A. niger SH-1, called AN-GpdA, could solve the above problems effectively. Furthermore, it can not only use glucose, but also xylose as a sole carbon source. Enzyme activity of AN-GpdA using xylose for fermentation reached 1 100.28 U/g of dry cell. We also used lignocellulose such as the hydrolysate of bagasse for fermentation with good performance. The result would provide a novel strategy for the utilization of bagasse.