Objective To study the correlation between the middle ear transfer function and the tympanoscle-rosis locations and severities,via idealized finite element simulations of the fixation effects of different parts of the middle ear.Methods A finite element model was developed based on human middle ear histological data,and the air-conduction sound transmission was simulated for verification.Mimicking tympanosclerosis with different loca-tions by increasing the Young's modulus of related tissues,the changes in the middle ear transfer function under tympanic membrane,ligaments,and joint fixations were calculated.Results Limited hardening of eardrum did not influence the sound transmission(＜5 dB).Ligaments hardening(including the superior mallear ligament,superior incudal ligament,and the posterior incudal ligament)induced fixations of the ossicular chain and caused low-to-mid velocity drop down of the tympanic membrane umbo and the stapes footplate.The results indicated low-to-mid fre-quency hearing loss,about 40 dB when the ligaments were fully fixed.The sound transmission was not affected by incudomalleolar joint,a slightly high frequency improvement(0～6 dB)occurred when the incudostapedial joint got hardened.Significant low-to-mid frequency drop was found for the stapes footplate velocity in the case of otosclero-sis,while the velocity of tympanic membrane umbo was not significantly affected.Conclusion Tympanosclerosis in-fluences middle ear sound transferring by increasing the stiffness of the system,the effects are sensitive to tympano-sclerosis locations and severity.Moreover,as the hardened location approaches the stapes,the variations of tympan-ic membrane and stapes footplate movement can be quite different.

Objective To study the correlation between the middle ear transfer function and the tympanoscle-rosis locations and severities,via idealized finite element simulations of the fixation effects of different parts of the middle ear.Methods A finite element model was developed based on human middle ear histological data,and the air-conduction sound transmission was simulated for verification.Mimicking tympanosclerosis with different loca-tions by increasing the Young's modulus of related tissues,the changes in the middle ear transfer function under tympanic membrane,ligaments,and joint fixations were calculated.Results Limited hardening of eardrum did not influence the sound transmission(＜5 dB).Ligaments hardening(including the superior mallear ligament,superior incudal ligament,and the posterior incudal ligament)induced fixations of the ossicular chain and caused low-to-mid velocity drop down of the tympanic membrane umbo and the stapes footplate.The results indicated low-to-mid fre-quency hearing loss,about 40 dB when the ligaments were fully fixed.The sound transmission was not affected by incudomalleolar joint,a slightly high frequency improvement(0～6 dB)occurred when the incudostapedial joint got hardened.Significant low-to-mid frequency drop was found for the stapes footplate velocity in the case of otosclero-sis,while the velocity of tympanic membrane umbo was not significantly affected.Conclusion Tympanosclerosis in-fluences middle ear sound transferring by increasing the stiffness of the system,the effects are sensitive to tympano-sclerosis locations and severity.Moreover,as the hardened location approaches the stapes,the variations of tympan-ic membrane and stapes footplate movement can be quite different.

【Objective】 To analyze the risk factors related to the number of RBCs transfusion in neonates with neonatal respiratory distress syndrome (NRDS), and to explore the complications and the predictive indicators related to the increase of RBCs transfusion frequency. 【Methods】 NRDS newborns admitted to our hospital from January 2017 to January 2019 were selected and divided into three groups according to the number of RBCs transfusion, namely, non-transfusion group, 1~ 2 times group, and ≥3 times group. The clinical data and complications of the three groups were compared, and the risk factors leading to the increase of the number of blood transfusion were analyzed. 【Results】 Such factors as maternal age ≥35 years old, gestational age, birth weight, hemoglobin(Hb) at admission, non-invasive ventilation time, hospitalization time in neonatal intensive care unit(NICU), total enteral feeding time affected the blood transfusion frequency of the three groups(χ²=14.24, F=28.44, 41.70, 60.05, 3.83, 5.97, 4.40, P<0.05). The incidence of necrotizing enterocolitis (NEC), septicemia and feeding intolerance in blood transfusion ≥3 times group was significantly higher than that in 1~2 times group and non-transfusion group (χ²=19.30, 18.68, 6.98, P<0.05). Multivariate logistic regression analysis showed that birth weight, Hb at admission, length of stay in NICU and time of reaching total enteral feeding were independent risk factors for≥ 3 times of blood transfusion (OR=-3.942, -0.186, 0.530, 0.324, P<0.05). The ROC curve showed that birth weight and Hb at admission were effective in predicting blood transfusion ≥3 times, and the area under the ROC curve were 0.846 and 0.802, respectively, and the truncation values were 2.315 kg and 157.5 g/L. 【Conclusion】 Feeding intolerance, NEC and septicemia are the complications of the increased transfusion frequency in children with NRDS, and birth weight and hemoglobin at admission are effective in predicting blood transfusion ≥ 3 times.