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Prior to the COVID-19 pandemic, our research group initiated a pediatric practice-based randomized trial for the treatment of childhood obesity in rural communities. Approximately 6 weeks into the originally planned 10-week enrollment period, the trial was forced to pause all study activity due to the COVID-19 pandemic. This pause necessitated a substantial revision in recruitment, enrollment, and other study methods in order to complete the trial using virtual procedures. This descriptive paper outlines methods used to recruit, enroll, and manage clinical trial participants with technology to obtain informed consent, obtain height and weight measurements by video, and maintain participant engagement throughout the duration of the trial.
The study team reviewed the IRB records, protocol team meeting minutes and records, and surveyed the site teams to document the impact of the COVID-19 shift to virtual procedures on the study. The IRB approved study changes allowed for flexibility between clinical sites given variations in site resources, which was key to success of the implementation.
All study sites faced a variety of logistical challenges unique to their location yet successfully recruited the required number of patients for the trial. Ultimately, virtual procedures enhanced our ability to establish relationships with participants who were previously beyond our reach, but presented several challenges and required additional resources.
Lessons learned from this study can assist other study groups in navigating challenges, especially when recruiting and implementing studies with rural and underserved populations or during challenging events like the pandemic.
Radon gas is a serious contaminant in radiocarbon dating by radiometry. The low specific ionizations associated with the α-particle emitting radon and its β-particle emitting daughters overlap within the 14C counting window. Elimination of radon is therefore imperative for precise 14C age determinations. This paper deals with the sources and mechanism of incorporation of radon affecting 14C dating by liquid scintillation (LS) counting, and reviews conventional radon elimination practices in 14C laboratories. It demonstrates, based on rigorous multichannel and multiparameter α- and β-particle spectral analyses of some 1000 benzene samples, that parent radium is not present and that its daughter radon is quantitatively eliminated during dynamic vacuum recovery of benzene at −78°C. However, the radon-free benzene can be recontaminated by exposure to air containing traces of radon, such as is common in concrete or low-lying laboratories. The use of radon-free air, when exposing the benzene to the atmosphere, and the monitoring of radon counts from the environment and sample benzene in a fixed ‘radon window', are essential prerequisites to the quality control of 14C age determinations in very low background systems.
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