Considering participants' compliance, none response and withdraw, a sample size of 100 per arm is needed.
The diagnosis of meningitis is made by analyzing a sample of cerebrospinal fluid withdrawn by needle from the spinal canal (i.e., by lumbar puncture).
The course of the reaction and the products were monitored by periodically withdrawing a small sample (20 μl) of the reaction mixture, which was analyzed by liquid chromatography.
At various times, a sample of the culture is withdrawn and its optical density (OD) is determined.
A sample of 1 mL was withdrawn at different time intervals and the absorbance was measured at 427 nm.
To measure the amount of sulphur contained in a known volume of gas, a sample of saturated gas is withdrawn from the equilibrium cell by the way of a flash and pass through a trapping solution.
Mixture quality is often assessed by withdrawing a number of samples of proscribed size and calculating the variance of the compositions.
Core needle biopsy (CNB): This procedure uses a wide-diameter needle to withdraw samples of tissue up to.5 inches (1.27 cm) long.
Upon circulation of the transcripts, one participant withdrew leaving a final sample of 14 interviews for analysis.
After withdrawing an arterial blood sample, the ratio of alveolar dead space (VDA) to VT was calculated as: VDA/VT = 1 – (PETCO2/PaCO2) where PETCO2 is end-tidal CO2 measured at the plateau of the expired CO2 curve.
