Human Upper Respiratory System Research Articles

Towards understanding of inhalation exposure of pilots in the control cabin environment

Transport characteristics of TVOC in cockpits of commercial airliners have not been carefully studied relative to passenger cabins, and VOC emissions are currently not well regulated by the standards (e.g. ASHRAE, FAA, etc.). This study numerically performed a comprehensive assessment of cockpit environment using the developed all-in-one model, for the first time, integrating a full-scale A320 cockpit model and detailed manikins with 3D-rebuilt nasal cavity models. A generalised total volatile organic compound (TVOC) was selected as one representative gaseous contaminant and two representative emission scenarios in the cabin environment (aged and new aircraft) were analysed. Potential risky regions of the nasal system after inhaling the given contaminants were further evaluated. The outcomes demonstrated that windshield inlets were the key determinant of yielding the strong local vortex in the pilot’s near field, which could potentially promote the contaminant lock-up. For aged aircraft, the average contaminant concentration in the pilots’ breathing zone was nearly half of that in a brand-new aircraft, while TVOC concentrations were significantly higher in the human upper respiratory system than those detected in the breathing zones for both cases, particularly for vestibule, olfactory, sinus and nasopharynx regions. Olfactory regions were the most affected region in two cases, with an approximately 20% increase in the case of brand-new aircraft compared to an aged one. This study enlightened a novel pathway to assess indoor environment, from tracing the pollutants from the release source to ultimately quantifying the contaminant distribution characteristics in human upper respiratory system.

Development of a mathematical correlation for polydisperse non-spherical drug particle deposition in the human upper respiratory system

Development of a mathematical correlation for polydisperse non-spherical drug particle deposition in the human upper respiratory system

Development of a mathematical correlation for polydisperse non-spherical drug particle deposition in the human upper respiratory system

Development of a mathematical correlation for polydisperse non-spherical drug particle deposition in the human upper respiratory system

Study of the Airflow Patterns in Human Upper Respiratory System Under Circular Breathing

Study of the Airflow Patterns in Human Upper Respiratory System Under Circular Breathing

Distribution of two VIP-related peptides, helospectin and pituitary adenylate cyclase activating peptide (PACAP), in the human upper respiratory system

Helospectin (HS) and pituitary adenylate cyclase activating peptide (PACAP) are newly discovered peptides isolated from the salivary gland venom of the lizard Heloderma horridum and the ovine hypothalamus, respectively. They show chemical similarities to vasoactive intestinal polypeptide (VIP), appear to have similar functions and are present in gut, brain, lung, male and female genitourinary tract. In the present study, the distribution of the helospectin and PACAP-27 in the human upper respiratory system was investigated using indirect immunofluorescence and electron-microscopical ABC-pre-embedding methods. Immunohistochemistry revealed helospectin-like (HS-LI) and PACAP-like (PACAP-LI) immunoreactivity in nerve fibers in human nasal, the larynx (vocal cord, ventricular fold, epiglottis), the tongue and the soft palate mucosa. Helospectin-LI and PACAP-LI containing nerve fibers were mainly found in close association to blood vessels and glandular structures. Colocalization studies carried out by application of double immunofluorescence showed that HS and/(or) PACAP-LI coexist with VIP in apparently the same nerve fibers in the upper respiratory system, although single nerve fibers seem to exclusively express helospectin. The localization patterns of helospectin and PACAP-LI in the human upper respiratory system suggests their possible involvement in the regulation of secretory activities and local blood flow.