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An Improved Approximation for DIPPR-Based Predicting Speed of Sound in Long-Chained n-Alkanes

100%

Postnikov E. B. , Nedyalkov Y. V. , Polishuk I.

Densities, Viscosities and Speeds of Sound of Binary Mixtures of Stereoisomeric Decalins

100%

Siporska A. , Szydłowski L.

2007

tom Vol. 81, nr 4

599-605

Densities, viscosities and speeds of sound for the binary mixture of cis- and transdecalins have been measured over the whole composition range at 293.15 K and 305.15 K. The limiting partial volumes, excess volumes, deviations in viscosity and isentropic compressibilitywere calculated. It appeared that the mixture of stereoisomeric decalins is characterized by a moderate excess volume and relatively small deviations in viscosity and isentropic compressibility. The results were fitted to the Redlich – Kister equation.

Accuracy of quantitative ultrasound parameters in the diagnosis of osteoporosis

75%

Pais R. , Campean R. , Simon S.-P. , Bolosiu C. , Muntean L. , Bolosiu H.

Open Medicine

2010

tom 5

nr 4

478-485

Quantitative ultrasound (QUS) is of increasing interest for evaluation of osteoporosis because, compared with dual-energy X-ray absorptiometry (DXA), it is portable, less expensive, and radiation-free. The aim of our study was to determine the sensitivity, specificity, and cut-off values of quantitative ultrasound parameters in identifying patients with osteoporosis compared to the World Health Organization (WHO) standard definition. We performed a cross-sectional investigational study of 73 subjects, and determined total hip and lumbar spine T-scores by dual-energy X-ray absorptiometry (DXA) (Prodigy Advance Lunar-GE). The QUS parameters (broadband ultrasound attenuation [BUA], speed of sound, bone mineral density, the stiffness index, and QUS T-score) were determined with Sahara Hologic equipment. The AUC was 0.81 (95% CI 0.67–0.95, p<0.05) for speed of sound (SOS) and 0.76 (95% CI 0.62–0.90, p<0.05) for BUA for the patients with DXA T-scores ≥ −1 DS; the cut-off values were 1542.2 meters per second for SOS and 63.3 dB/MHz for BUA. In patients with DXA T-scores ≤ − 2.5 DS, AUC was 0.80 (95% CI 0.70–0.90, p<0.05) for SOS, and 0.76 (95% CI 0.65–0.87, p<0.05) for BUA. The cut-off values were 1504.95 meters per second for SOS and 49.5 dB/MHz for BUA. Pearson correlation coefficients were positive and statistically significant (> 50%) for all QUS parameters in both groups, (2-tailed, p<0.05). QUS parameters correctly identified normal patients (false negative 34.21% and false positive 2.53%) and those with osteoporosis (false negative 8.55% and false positive 7.82%). The patients with QUS parameters between the cut-off values corresponding to DXA T-scores of −1 SD and − 2.5 SD should be further evaluated by DXA.

Application of Ultrasonic Methods for Evaluation of High-Pressure Physicochemical Parameters of Liquids

75%

Kiełczyński P. , Ptasznik S. , Szalewski M. , Balcerzak A. , Wieja K. , Rostocki A. J. , Kiełczyński P. , Ptasznik S. , Szalewski M. , Balcerzak A. , Wieja K. , Rostocki A. J.

nr 2