BACKGROUND Δ(9)-Tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), and cannabinol (CBN) were measured in breath following controlled cannabis smoking to characterize the time course and windows of detection of breath cannabinoids. METHODS Exhaled breath was collected from chronic (≥4 times per week) and occasional (<twice per week) smokers before and after smoking a 6.8% THC cigarett...

Breath monitoring is a non-invasive, safe, and repeatable approach to determining the respiratory, gastrointestinal, and general health status of humans and other mammals. Breath samples could be detected in two ways—directly sensing exhaled breath (EB) or chilling the EB to obtaining the exhaled breath condensate (EBC). Each has its advantages and disadvantages but they are both affected by di...

This paper presents a dual approach to the study of breath sounds in singing, consisting of an acoustic analysis of breath sounds, and development of an automatic breath detection system. Previouswork on automatic breath detection were based on relatively simple features that were postulated to be relevant to the detection. In contrast, this study starts with a detailed acoustic analysis of bre...

BACKGROUND Vigorous outdoors exercise during an episode of air pollution might cause airway inflammation. The purpose of this study was to examine the effects of vigorous outdoor exercise during peak smog season on breath pH, a biomarker of airway inflammation, in adolescent athletes. METHODS We measured breath pH both pre- and post-exercise on ten days during peak smog season in 16 high scho...

Measuring the concentration of alcohol in body fluids represents a large part of the workload at forensic science and toxicology laboratories. In traffic-law enforcement, breath-alcohol testing is used worldwide for roadside screening and for evidential purposes. Many jurisdictions have adopted per se laws which make it a crime to drive with a blood- or breath-alcohol concentration above a pres...

Breath hydrogen and methane are specific end products of colonic fermentation, a process which may play a protective role against colon cancer. To assess the possibility of using these markers in epidemiological studies, we characterized the intra- and intersubject variability of breath hydrogen and methane excretion over 15 consecutive days among 32 men and women of various ethnic backgrounds ...

Accepting that the evaluation of the aerobic energy system contribution is very important for swimming training diagnostics purposes and that oxygen uptake kinetics (VO2) is one of the most used parameters in that task, we purposed to assess the variability of the peak VO2 and VO2max values obtained in a 200 m front crawl effort, using five different presentation intervals: breath-by-breath and...

Background Breath-holding spells (BHS) are brief periods when young children stop breathing for up to 1 minute and are widely recognized types of non-epileptic severe occasions in early stages of childhood. This study aimed to evaluate QTd and QTc changes in children with breath-holding spells compared with healthy children. <stron...