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The dynamic characteristics of air-conditioning in the human nasal cavity during a respiratory cycle were investigated using unsteady numerical simulations to assess whether inhaled air is sufficiently conditioned by the nasal cavity. Variations in the epithelial surface temperature, surface heat, and water vapor fluxes were found to vary significantly during inspiration while providing substantial air conditioning to the inhaled air, but variations and magnitudes were significantly reduced during the expiration period. Air temperature (31.3-35.3 °C) and relative humidity (85.1-100 %) in the nasopharynx exhibited significant variations during inspiration. Flow rate-weighted average values of the air temperature and relative humidity during inspiration were estimated to be 32.0 °C and 89.1 %, respectively. Inhaled air did not attain alveolar conditions before reaching the nasopharynx, and was therefore thought to be insufficiently conditioned by the nasal cavity alone. A steady flow of approximately 250 mL/s appears to be useful for evaluating the accumulated thermal state of air in the nasopharynx during inspiration., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In the presence of nasal septal deviation, the airflow can be skewed to the convex side of the airway. Asymmetry of the airflow partition can be aggravated if the decongestion phase of the nasal cycle occurs on the same side. This numerical study investigates the variation in the airflow partition over time during inspiration and the corresponding changes in relative humidity when septal deviation is combined with the nasal cycle. In the nasal cavities with a decongested convex side, the variation in the airflow partition ratio observed over time was larger than that in the nasal cavities not influenced by the nasal cycle. In addition, the decrease in the relative humidity of the convex side was larger, resulting in a relative humidity of as low as 76.3 %. Therefore, the convex side of the deviated cavity was more prone to nasal dryness under the influence of the nasal cycle. [ABSTRACT FROM AUTHOR]

Septoturbinoplasty is a surgical procedure that can improve nasal congestion symptoms in patients with nasal septal deviation and inferior turbinate hypertrophy. However, it is unclear which physical domains of nasal airflow after septoturbinoplasty are related to symptomatic improvement. This work employs computational fluid dynamics modeling to identify the physical variables and domains associated with symptomatic improvement. Sixteen numerical models were generated using eight patients' pre- and postoperative computed tomography scans. Changes in unilateral nasal resistance, surface heat flux, relative humidity, and air temperature and their correlations with improvement in the Nasal Obstruction Symptom Evaluation (NOSE) score were analyzed. The NOSE score significantly improved after septoturbinoplasty, from 14.4 ± 3.6 to 4.0 ± 4.2 (p < 0.001). The surgery not only increased the airflow partition on the more obstructed side (MOS) from 31.6 ± 9.6 to 41.9 ± 4.7% (p = 0.043), but also reduced the unilateral nasal resistance in the MOS from 0.200 ± 0.095 to 0.066 ± 0.055 Pa/(mL·s) (p = 0.004). Improvement in the NOSE score correlated significantly with the reduction in unilateral nasal resistance in the preoperative MOS (r = 0.81). Also, improvement in the NOSE score correlated better with the increase in surface heat flux in the preoperative MOS region from the nasal valve to the choanae (r = 0.87) than in the vestibule area (r = 0.63). Therefore, unilateral nasal resistance and mucous cooling in the preoperative MOS can explain the perceived improvement in symptoms after septoturbinoplasty. Moreover, the physical domain between the nasal valve and the choanae might be more relevant to patient-reported patency than the vestibule area. [ABSTRACT FROM AUTHOR]

The Global Climate Observing System Reference Upper-Air Network (GRUAN) with high-verticalresolution radiosonde data at three Arctic stations and European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data (ERA5) were used to investigate the characteristics of multiple temperature inversions (TI) and humidity inversions (HI) in this study. It is found that surface-based inversion (SBI) at two coastal stations exists throughout the whole year, mainly due to the surface cooling in cold months, advection warm months, and the orography of the stations. The seasonal variation of surfaced-based HI (SBHI) frequency is similar to that of SBI, and its intensity is greater in summer because of the larger air moisture content. The frequency of the first elevated TI (EI1) and HI (EHI1) are both higher than that of the surface-based ones. The second elevated TI/HI layer (EI2/EHI2) is shallower and weaker than that of the EI1/EHI1. At two coastal stations, EI1 caused by warm advection is thicker and stronger than that caused by subsidence. At the station farther from the coast, EI1 caused by subsidence is higher, thinner, and stronger. The top height and depth of the EHI2 both show seasonal variations, with larger values in the cold months. EHI1 tends to be formed by the TI, whereas EHI2 is dominant by humidity advection at all studied stations. HI under the influence of TI is usually thicker and stronger than that formed by humidity advection. The coexistence of EI and EHI is the most frequent inversion structure at these stations. [ABSTRACT FROM AUTHOR]

Calyx-end browning in ‘Fuyu’ persimmon (Diospyros kakiThumb.) fruits was investigated to learn how meteorological factors and calcium (Ca) concentrations in soil, fruiting shoot, and fruit were related to the symptom occurrences, how longitudinal sections in fruits and fruiting height contribute nutrient partitioning of fruits, and how Ca soaking into fruits affects the cell structure in the flesh. Low humidity with extended radiation reduced fruit browning. Fruiting shoots without browning fruits had greater Ca and lower potassium (K) concentrations than the shoots with browning fruits. Proximal flesh had a greater Ca concentration than middle and distal end parts in calyx-end browning fruits that had lower ratios of Ca:K, Ca:magnesium (Mg), and Ca:K+Mg. Nutrient concentrations were similar to the fruiting height within a canopy, except for manganese, and boron. Calcium dipping into fruit under a vacuum increased Ca concentration in flesh and core parts, which had apparent cell wall strength. [ABSTRACT FROM PUBLISHER]

The air-conditioning characteristics in nasal cavity models obtained from two subjects exhibiting different degrees of the nasal cycle states in terms of the airflow partition were investigated using computational fluid dynamics. A constant inspiratory flow rate of approximately 250 mL/s was considered, and the air temperature and relative humidity at the inlet were assumed to be 25 °C and 35%, respectively. The air-conditioning capacities of the congested and decongested sides were assessed by the amounts of epithelial heat and water vapor transferred to the inhaled air through the airway from the nostrils to the end of the septum. The results revealed that the air temperature and relative humidity near the end of the septum, respectively, reached approximately 31.4–32.5 °C and 81.4–88.0% in the decongested sides and 34.0–35.9 °C and 95.3–100% in the congested sides. The differences seen in the air temperatures and relative humidity between the congested and decongested sides were found to be larger in the cavity model that showed a larger degree of reciprocal change in the airflow rate. From a fluid mechanics perspective, while the congested side is in a rest period during the nasal cycle such that a lower amount of airflow is transported through it, this side, in effect, works to provide assistive air-conditioning capacity to the nasal cavity and aids when insufficiently conditioned airflow passes through the decongested side so that the inhaled air merging after the septum can approach the alveolar condition favorably through the nasopharynx. • Air-Conditioning characteristics were investigated in presence of nasal cycle states. • Air temperature and relative humidity distributions were examined. • Air temperature and relative humidity were higher in the congested side. • The decongested side is not able to properly condition increased airflow rate. [ABSTRACT FROM AUTHOR]