Effect of CT manifestations of cholesteatomatous otitis media on matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and interleukin-6 (IL-6) in the serum of patients was investigated. A total of 176 patients with cholesteatomatous otitis media were enrolled as the study group and 181 patients with simple otitis media were enrolled as the control group. Patients were admitted to the Changxing People's Hospital from January 2010 to December 2016. The patients in the study group were classified according to the 64-row spiral CT diagnosis. The expression levels of MMP-2, MMP-9 and IL-6 in the serum of the selected patients were detected by ELISA. MMP-2, MMP-9 and IL-6 expression levels in the study group were higher than those in the control group (P<0.05). MMP-2, MMP-9 and IL-6 expression levels in the serum of the patients with injured ossicular chain were significantly higher than those in the serum of patients with injured malleus or incus (P<0.05), and significantly higher than those in the serum of patients with intact ossicular chain (P<0.05). The levels of MMP-2, MMP-9 and IL-6 in the serum of the patients whose malleus or incus was injured were higher than those in the serum of the patients with intact ossicular chain (P<0.05). There was an obvious positive correlation between the injury degree of different sclerotins in CT manifestations of the patients in the study group and MMP-2, MMP-9, and IL-6 (P<0.05). The high expression levels of MMP-2, MMP-9 and IL-6 in the serum of patients with cholesteatomatous otitis media were positively correlated with the injury degree of ossicle, which may be a sign of poor prognosis of cholesteatomatous otitis media.

To enhance the working efficiency and aerodynamic performance of the centrifugal fan in the air system of a cotton picker, a new type of centrifugal fan blade was designed by extracting the mid-arc section from the prototype blade and integrating an airfoil, which was transplanted and coupled to the mid-arc section. The design aimed to improve the airflow characteristics and performance of the centrifugal fan. By combining experimental data from centrifugal fans used in existing cotton-picker air systems and employing computational fluid dynamics (CFD) methods, the internal flow field structure of the centrifugal fan was simulated. This study focused on investigating the aerodynamic performance of the new centrifugal fan blade and its impact on improving the internal flow patterns within the centrifugal fan. The results of the flow field visualization analysis indicate that the new blade design exhibits excellent aerodynamic performance, improving the flow distribution within the centrifugal fan. It enhances the uniformity of the outlet airflow, reduces the occurrence of localized “jet-wake” phenomena at the impeller’s outlet, suppresses the generation and development of vortices in the flow channel, and reduces local energy losses within the impeller. These improvements contribute to an increase in the fan’s efficiency. Under rated operating conditions, the efficiency of the prototype fan was measured at 60.3%, while the optimized fan achieved an efficiency of 64.8%. This signifies a significant improvement in the efficiency of the centrifugal fan.