Background: Several multiphase flow analyses have been developed to predict the fate of particles used in inhalation drug delivery; however, the collapse of droplets during their passage through respiratory tract has not been investigated. Objective: To assess the probability of droplet collapse in the upper respiratory tract.Methods: A 3D model of mouth-to-second generation airway after the tr...

background: several multiphase flow analyses have been developed to predict the fate of particles used in inhalation drug delivery; however, the collapse of droplets during their passage through respiratory tract has not been investigated. objective: to assess the probability of droplet collapse in the upper respiratory tract. methods: a 3d model of mouth-to-second generation airway after the t...

A substantial proportion of patients with chronic obstructive pulmonary disease (COPD) develops various degree of intrathoracic tracheal collapsibility. We studied whether the magnitude of intrathoracic tracheal collapsibility could be different across clinical phenotypes and sex in COPD. Intrathoracic tracheal collapsibility measured at paired inspiratory-expiratory low dose computed tomograph...

Maximal expiratory flow in chronic obstructive pulmonary disease (COPD) could be reduced by three different mechanisms; loss of lung elastic recoil, decreased airway conductance upstream of flow-limiting segments; and increased collapsibility of airways. We hypothesized that decreased upstream conductance would be related to inflammation and thickening of the airway walls, increased collapsibil...

Folded states of single domain globular proteins are compact with high packing density. The radius of gyration, Rg, of both the folded and unfolded states increase as Nν where N is the number of amino acids in the protein. The values of the Flory exponent ν are, respectively, ≈⅓ and ≈0.6 in the folded and unfolded states, coinciding with those for homopolymers. However, the extent of compaction...

Increased upper airway collapsibility has been suspected of being involved in the pathogenesis of sleep-related diseases. It is assumed that patients with severe obstructive sleep apnea syndrome (OSAS) show a stronger collapse of the upper airway compared with habitual snorers. It was the objective of this study to analyze the patterns of upper airway collapse in habitual snorers and patients w...

In this paper, we discuss several concepts in causal inference in terms of causal diagrams proposed by Pearl (1993, 1995a, b), and we give conditions for non-confounding, homogeneity and collapsibility for causal e€ects without knowledge of a completely constructed causal diagram. We ®rst introduce the concepts of non-confounding, conditional non-confounding, uniform non-confounding, homogeneit...

BACKGROUND We investigated correlations between lung volume collapsibility indices and pulmonary function test (PFT) results and assessed lobar differences in chronic obstructive pulmonary disease (COPD) patients, using paired inspiratory and expiratory three dimensional (3D) computed tomography (CT) images. METHODS We retrospectively assessed 28 COPD patients who underwent paired inspiratory...

We hypothesized that upper airway collapsibility is modulated dynamically throughout the respiratory cycle in sleeping humans by alterations in respiratory phase and/or airflow regimen. To test this hypothesis, critical pressures were derived from upper airway pressure-flow relationships in six tracheostomized patients with obstructive sleep apnea. Pressure-flow relationships were generated by ...

In many regions in China there is a wide distribution of dead-weight collapsible loess that experience frequent disasters resulting in enormous losses to national property. Loess collapsibility is the leading cause of disasters in loess areas. Many international scholars are working collaboratively to avoid property losses and human casualties caused by the collapsible loess. Loess collapsibili...