As part of development of performance standards, the International Organization for Standardization (ISO) technical committee, ISO/TC 94/SC 15 Respiratory protective devices (RPD), adopted work of breathing (WOB) to evaluate airflow resistance for all designs (classes) of respiratory protective devices. The interests of the National Institute for Occupational Safety and Health's (NIOSH) National Personal Protective Technology Laboratory (NPPTL) are to compare the proposed WOB method and results for current RPD with those for present resistance methods. The objectives here were to assemble a method to meet the ISO SC15 standards, validate operation and conformance, and assess repeatability of WOB measurements for RPD. WOB method implementation and use followed standards ISO 16900-5:2016 and ISO 16900-12:2016. Volume-averaged total work of breathing (WOB/V where V is tidal volume) determined for standard orifices was analyzed for variation and bias. After fabrication and assembly, the method gave preliminary verification orifice results that met ISO requirements and were equivalent to those from other laboratories. Evaluation of additional results from RPD testing showed tidal volume and frequency determined compliance. Appropriate adjustments reduced average absolute bias to 1.7%. Average coefficient of variation for WOB/V was 2.3%. Over 97% of results obtained during significant use over time met specifications. WOB/V for as-received air-purifying and supplied-air RPD were repeatable (p<0.05). WOB/V for unsealed half mask air-purifying RPD was an average of 31% lower compared to sealed. When experimental parameters were appropriately adjusted, the ISO WOB method implemented by NIOSH NPPTL consistently provided ISO-compliant verification WOB/V. Results for appropriately sealed RPD were reproducible.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10273392 | PMC |
Infect Immun
December 2024
Laboratory of Applied Immunology, Institute of Biology Sciences, University of Brasília, Brasília, Brazil.
Dormancy is an adaptation in which cells reduce their metabolism, transcription, and translation to stay alive under stressful conditions, preserving the capacity to reactivate once the environment reverts to favorable conditions. Dormancy and reactivation of () are closely linked to intracellular residency within macrophages. Our previous work showed that murine macrophages rely on the viable but not cultivable (VBNC-a dormancy phenotype) fungus from active , with striking differences in immunometabolic gene expression.
View Article and Find Full Text PDFPediatr Pulmonol
December 2024
Department of Emergency Medicine, Ajou University School of Medicine, Suwon, Republic of Korea.
Objectives: To investigate the clinical implications of the obstructive pattern on plain chest radiography, defined as peribronchial cuffing or hyperinflation, in young children with severe lower respiratory tract infections (LRTIs).
Methods: We reviewed all children aged 3‒59 months with LRTIs who underwent radiography and polymerase chain reaction in a Korean emergency department from 2016 through 2020. The radiographs were read as consolidation, peribronchial cuffing, or hyperinflation, with each interrater reliability computed.
Int J Cardiol Congenit Heart Dis
December 2024
Royal Brompton Hospital, London, United Kingdom.
Nat Sci Sleep
December 2024
Department of Pulmonary and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, 610064, People's Republic of China.
Objective: To investigate whether self-reported symptoms of obstructive sleep apnea (OSA), including snoring, snorting/stopping breathing, and sleepiness, are associated with increased risk of kidney stones.
Methods: This cross-sectional study was conducted based on the 2015-2020 National Health and Nutrition Examination Survey (NHANES). Self-reported symptoms of OSA and history of kidney stones were diagnosed via questionnaires.
Cureus
November 2024
Internal Medicine, Johnston Memorial Hospital, Abingdon, USA.
Ludwig's angina (LA) is a rapidly progressive cellulitis-causing airway obstruction that can spread through fascial planes to the floor of the mouth and into the mediastinum. Early recognition and treatment are essential for preventing potentially fatal complications. Diagnosis is based on clinical suspicion and confirmed through CT and ultrasound (US).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!