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Objective: To compare the mechanical properties of the supraspinatus tendon in different age groups using Supersonic Shearwave Imaging (SSI) elastography. Methods: We evaluated 38 healthy individuals of both genders, 20 being in the range of 20 to 35 years and 18 being over 60 years. The shear modulus of the supraspinatus tendon was measured by SSI elastography, always on the right side. Means between age groups were compared and statistically analyzed using the Shapiro-Wilk normality test followed by the student’s t-test and were established as a statistically significant value of p ≤ 0.05. Results: A statistically significant difference was observed when the mean values of the shear modulus of the supraspinatus tendon of young adults (23.98 ± 9.94 KpA) were compared with those of older adults (17.92 ± 6.17 KpA). Conclusion: We found a difference between the means of the shear modulus measured by the SSI elastography, showing a significant decrease of the shear modulus with the chronological age progression. Level of Evidence III, Diagnostic Studies - Investigating a Diagnostic Test.

Introduction: Currently, little attention is given to the muscle architecture reliability studies of the hamstring using a robust statistical. Our purpose was to determine the reliability of ultrasound measurements of muscle thickness, fascicle length and pennation angle of the biceps femoris and semitendinosus muscles, including heteroskedasticity and internal consistency analyses. Methods: Two images of biceps femoris and semitendinosus at 50% of the thigh length were acquired from 21 volunteers, in two visits. The parameters were measured three times in each image, and for each muscle. The reliability was analyzed by the intraclass correlation coefficient (ICC) and Cronbach's alpha (αCronbach). The relative standard error of the measurements (%SEM) were calculated and Bland-Altman plots were generated.

In recent years, an important class of new compounds, ionic liquids (ILs), has been investigated as additives for polymers. In this work, we carried out the synthesis of 4 different ILs: 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM.BF 4 ), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM.PF 6 ), and the chiral ILs acetyl-(À)menthol-1-buthylimidazole tetrafluoroborate ([amebim]BF 4 ) and acetyl-(À)menthol-1-buthylimidazole hexafluorophosphate ([amebim]PF 6 ). These ILs were added to poly(methyl methacrylate) (PMMA) in 10, 20 and 30% ratios by weight and the ILs, PMMA and the obtained materials (PMMA:ILs) were characterized by infrared, visible spectroscopy and atomic force microscope. The ILs added to PMMA did not provide significant changes in the infrared spectra, compared to pure PMMA. However, the absorption spectra in the visible region of the PMMA:ILs materials showed differences, compared to the spectrum of pure PMMA.

Purpose The purpose of this study was to investigate the variation in the Young's modulus (E) of bovine muscle samples as a function of temperature change generated by therapeutic ultrasound using ShearWave™ Elastography. Methods Initially, the bovine muscle was heated via therapeutic ultrasound with a frequency of 3 MHz, nominal intensity of 2 W•cm −2 , and application time of 2 min. Immediately following cessation of therapeutic irradiation, an E image was recorded and the stiffness was measured in circular area positioned at six depths (from 0.4 to 2.9 cm) in the center of the region of interest. Next, an E image was recorded every minute for the first 5 min. Over the next 30 min, an image was recorded every 5 min. Finally, an image was acquired 60 min after cessation of therapeutic irradiation. In the second test, the same experimental procedure was performed 60 min later with the physiotherapy equipment configured with a 10-min application time. Finally, during the ultrasonic irradiation of a new bovine muscle sample, the physiotherapeutic transducer was applied in a circular motion and with an angular velocity of 3.6 ± 0.3 rad•s −1 . Results In the first test, the bovine muscle E decreased from 212.2 ± 32.8 to 80.1 ± 13.8 kPa at 0.4-cm depth, as the temperature increased from 18.2 to 44.9 °C. This effect was reversed when the temperature decreased. In the second test, denaturation and cell death occurred, so an artifact appeared in the elastographic image and the ShearWave™ Elastography did not capture the E from the depth of 1.9 cm. Conclusion We confirmed that it is possible to use ShearWave™ Elastography to investigate heat-induced changes in the elastic modulus of biological tissue.

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