An Improved Method for Determining Urease Activity from Electrical Conductivity Measurements.

We present an improved approach to evaluating the activity of urease from electrical conductivity (EC) measurements. In this approach, chemical equilibrium modeling via PHREEQC is used in conjunction with empirical equations for computing EC to develop a function that relates the increase in EC during urea hydrolysis in a closed reactor to the concentration of ammonium species present (and concentration of urea remaining) in the reaction solution. By applying this function to data from continuous measurement of EC during urea hydrolysis, we obtain a profile of the concentration of the urea substrate with time, which is then used to determine the urease activity.

Imaging volumes during COVID-19: A Victorian health service experience.

Background: The World Health Organisation declared the coronavirus disease 2019 (COVID-19) a pandemic on March 11, 2020. While globally, the relative caseload has been high, Australia's has been relatively low. During the pandemic, radiology services have seen significant changes in workflow across modalities and a reduction in imaging volumes.