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• This study used ultrasound instantaneous frequency for evaluating the clinical severity of DMD. • Clinical measurements were performed for validations. • The accuracy to characterize the walking function of patients was 91.76%. • The proposed method benefits future DMD evaluation and management. Duchenne muscular dystrophy (DMD) results in loss of ambulation for the patients. Ultrasound attenuation correlates with fat content in muscles, resulting in changes in signal frequency. The Hilbert–Huang transform (HHT) allows time–frequency analysis with high time–frequency resolution. This study explored the feasibility of using the instantaneous frequency (IF) obtained from the HHT to diagnose the walking function of patients with DMD. Eighty-five participants (12 control and 73 patients with DMD) underwent a standard-care ultrasound examination of the gastrocnemius to acquire raw image data for ultrasound B-mode and IF calculations, which were compared with the DMD stage using Pearson correlation and receiver operating characteristic (ROC) curve analyses. With increasing DMD stage, the median IF decreased from 7.25 to 7.01 MHz (the correlation coefficient r = −0.73; the probability value p < 0.0001). The area under the ROC curve was 0.97 when using ultrasound IF to discriminate between ambulatory and nonambulatory patients (accuracy: 91.76%; sensitivity: 93.75%; and specificity: 90.57%). The study reveals that ultrasound IF has great potential in DMD evaluation and management. [ABSTRACT FROM AUTHOR]

Numerous experimental studies have shown that the interaction of ultrasound with different cell membranes can result in a wide range of non-thermal effects on different cells or their membrane, including increased membrane permeability, ultrasonic cavitation in cells, and increased gene and drug delivery. However, the molecular mechanism for the interaction between ultrasound and cell membrane remains unclear. In this study, we model ultrasonic waves as cycles of alternating positive and negative pressure, and then use atomic molecular dynamics simulation to investigate how the applied ultrasound affects the structure of cell membranes and the corresponding molecular distribution of dissolved gas. We find that ultrasound energy is concentrated more effectively on the hydrophobic core of the membrane because it causes a strong oscillation of membrane thickness while producing a much weaker response in the surrounding water. In addition, our simulations reveal a substantial effect of the ultrasonic frequency on redistribution of dissolved gas molecules, and only an ultrasound with a long period can result in a significant gas redistribution. [ABSTRACT FROM AUTHOR]

Abstract: Influence of ultrasound (US) on various unit operations in leather processing has been studied with the aim to improve the process efficiency, quality, reduce process time and achieve near-zero discharge levels in effluent streams as a cleaner option. Effect of US on substrate (skin/leather) matrix as well as substances used in different unit operations have been studied and found to be useful in the processing. Absorption of US energy by leather in process vessel at different distances from US source has been measured and found to be significant. Effect of particle-size of different substances due to sonication indicates positive influence on the diffusion through the matrix. Our experimental results suggest that US effect is better realized for the cases with pronounced diffusion hindrance. Influence of US on bioprocessing of leather has been studied and found beneficial. Attempts have also been made to improve the US aided processing using external aids. Operating US in pulse mode operation could be useful in order to reduce the electrical energy consumption. Use of US has also been studied in the preparation of leather auxiliaries involving mass-transfer resistance. Preliminary cost analysis carried out for ultrasound-assisted leather-dyeing process indicates scale-up possibility. Therefore, US application provide improvement in process efficiency as well as making cleaner production methods feasible. Hence, overall results suggest that use of US in leather industry is imminent and potential viable option in near future. [Copyright &y& Elsevier]