ABSTRACT
Objective@#To investigate the current situation of hearing health among college students and associated factors, and to provide a basis for universities and relevant departments to carry out hearing health work.@*Methods@#By using stratified random sampling method, 1306 students from 4 universities in Taiyuan were screened for hearing loss and were investigated with a questionnaire from March to November 2021. Data were analyzed by using the SPSS 19.0 statistical.@*Results@#The detection rate of hearing loss was 31.70%. The majority (51.91%) failed to pass the 4 000 Hz hearing screening. The total awareness rate of hearing problems was 58.96%. Logistic regression analysis showed that the total daily usage time of earphones >4 h/d, the duration of using earphones >1 h/time were positively correlated with positive screening for hearing loss among college students( OR=1.23, 1.14, P < 0.01), and good awareness of hearing health care and highest education of parents were negatively correlated with positive screening for hearing loss among coollege students( OR =0.54, 0.76, 0.37, P <0.05).@*Conclusion@#The awareness of hearing health care among college students is low. Universities and relevant departments should take targeted measures to provide the best hearing health care services.
ABSTRACT
Objective: To detect the thickness of silicon coating film for glass injection bottles by focused ion beam (FIB) emission scanning electron microscopy and investigate the stability and uniformity of the film.Methods: The boron silicon coating injection bottles were selected as the experimental samples and treated with such stability experiments as ultrasonic cleaning, high temperature resistance, heat resistance, water resistance, acid resistance and alkali resistance.The samples were vertically cut by the ion beam from an FIB field emission scanning electron microscope, and the thickness of the cutting face was measured by the built-in measuring module of the scanning electron microscope.Results: The thickness of silicon film was stable and uniform.Conclusion: The film thickness of glass bottles can be accurately detected, and the film stability and uniformity can be reflected directly and objectively by using an FIB double beam field emission scanning electron microscope.
ABSTRACT
Collagen is a kind of natural biomedical material and collagen based three-dimensional porous scaffolds have been widely used in skin tissue engineering. However, these scaffolds do not meet the requirements for artificial skin substitutes in terms of their poor mechanical properties, short supply, and rejection in the bodies. All of these factors limit their further application in skin tissue engineering. A variety of methods have been chosen to meliorate the situation, such as cross linking and blending other substance for improving mechanical properties. The highly biomimetic scaffolds either in structure or in function can be prepared through culturing cells and loading growth factors. To avoid the drawbacks of unsafety attributing to animals, investigators have fixed their eyes on the recombinant collagen. This paper reviews the the progress of research and application of collagen-based 3-dimensional porous scaffolds in skin tissue engineering.