1. The accuracy of measurements of flow rate and concentrations of O2 and CO2 in expiratory gas by indirect calorimetry (IC) using paediatric and adult circuits were assessed by mass spectrometry and a pneumotachogram, which have been proven as the most reliable instruments for these purposes. 2. In the paediatric circuit, all measurements were demonstrated to be reliable: error rates for flow rate, O2 concentration and CO2 concentration were +3.13, +2.66 and -6.63%, respectively. All were within the 10%, which is acceptable as a biological error. 3. However, in the adult circuit of IC, all measurements were reliable except for measurements of CO2 concentration: error rates for flow rate, O2 concentration and CO2 concentration were +2.82, +1.64 and +11.42%, respectively. 4. A fluctuation phenomenon of expiratory gas concentration was observed only in IC. Mass spectrometry did not show this phenomenon. This phenomenon seems to be derived from the IC machine itself.
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J Assist Reprod Genet
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Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, School of Clinical Medicine, The University of Hong Kong, Hong Kong, China.
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Department of Plant and Environmental Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Denmark.
Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) is commonly used for identification of compounds in complex samples due to the high chromatographic and mass spectral resolution provided. In subsequent data processing workflows, it is imperative to preserve this resolution to fully exploit the data. "Region of interest" (ROI) algorithms were introduced as a better alternative to equidistant binning for compressing HRMS data because they better preserve the mass spectral resolution.
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Novel psychoactive substances (NPS) have historically been difficult compounds to analyze in forensic toxicology. The identification, detection and quantitation of these analytes and their metabolites has been difficult due to their rapid emergence, short life span and various potencies. Advancements in analytical instrumentation are fundamental to mitigating these NPS challenges by providing reliable identification and sensitivity.
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School of Earth, Environment & Society, McMaster University, Hamilton, Ontario, Canada.
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