TY - JOUR A1 - Kellis, Eleftherios A1 - Ellinoudis, Athanasios A1 - Intziegianni, Konstantina T1 - Reliability of sonographic assessment of biceps femoris distal tendon strain during passive stretching JF - Ultrasound in Medicine & Biology N2 - The purpose of this study was to determine the intra-rater, inter-examiner and inter-observer reliability of biceps femoris long head (BFlh) tendon strain using ultrasound imaging. Nineteen patients (age: 20.4 +/- 0.35 y) were tested twice with a 1-wk interval. Each session included passive stretching from three different hip positions. Tests were performed independently by two examiners while BFlh tendon displacement (mm) and strain (%) were manually extracted from ultrasound video footages by two observers. Intra-rater comparisons revealed an intra-class correlation coefficient (ICC2,1) range of 0.87 to 0.98 and a variability less than 4.74%. Interexaminer comparisons revealed an ICC2,1 range of 0.83 to 0.99 and less than 4.69% variability. Inter-observer ICCs ranged from 0.93 to 0.97 with variability less than 4.89%. Using a well-defined scanning protocol, two experienced examiners attained high levels of intra-rater agreement, with similarly excellent results for inter-rater and inter-observer reliability for BFlh tendon displacement and strain. (E-mail: ekellis@phed-sr.auth.gr) (C) 2017 World Federation for Ultrasound in Medicine & Biology. KW - Hamstring KW - Tendon KW - Strain injury KW - Ultrasound KW - Imaging KW - Muscle Y1 - 2017 U6 - https://doi.org/10.1016/j.ultrasmedbio.2017.04.018 SN - 0301-5629 SN - 1879-291X VL - 43 SP - 1769 EP - 1779 PB - Elsevier CY - New York ER - TY - JOUR A1 - Zühlke, Martin A1 - Zenichowski, Karl A1 - Riebe, Daniel A1 - Beitz, Toralf A1 - Löhmannsröben, Hans-Gerd T1 - Subambient pressure electrospray ionization ion mobility spectrometry JF - International journal for ion mobility spectrometry : official publication of the International Society for Ion Mobility Spectrometry N2 - The pressure dependence of sheath gas assisted electrospray ionization (ESI) was investigated based on two complementary experimental setups, namely an ESI-ion mobility (IM) spectrometer and an ESI capillary - Faraday plate setup housed in an optically accessible vacuum chamber. The ESI-IM spectrometer is capable of working in the pressure range between 300 and 1000 mbar. Another aim was the assessment of the analytical capabilities of a subambient pressure ESI-IM spectrometer. The pressure dependence of ESI was characterized by imaging the electrospray and recording current-voltage (I-U) curves. Qualitatively different behavior was observed in both setups. While the current rises continuously with the voltage in the capillary-plate setup, a sharp increase of the current was measured in the IM spectrometer above a pressure-dependent threshold voltage. The different character can be attributed to the detection of different species in both experiments. In the capillary-plate experiment, a multitude of charged species are detected while only desolvated ions attribute to the IM spectrometer signal. This finding demonstrates the utility of IM spectrometry for the characterization of ESI, since in contrast to the capillary-plate setup, the release of ions from the electrospray droplets can be observed. The I-U curves change significantly with pressure. An important result is the reduction of the maximum current with decreasing pressure. The connected loss of ionization efficiency can be compensated by a more efficient transfer of ions in the IM spectrometer at increased E/N. Thus, similar limits of detection could be obtained at 500 mbar and 1 bar. KW - Ion mobility spectrometry KW - Electrospray ionization KW - Subambient pressure KW - Imaging Y1 - 2017 U6 - https://doi.org/10.1007/s12127-017-0215-x SN - 1435-6163 SN - 1865-4584 VL - 20 SP - 47 EP - 56 PB - Springer CY - Heidelberg ER -