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Introduction: The human voice is generated by the oscillation of the vocal folds induced by exhalation airflow. Consequently, the characteristics of these oscillations and the primary sound signal are controlled by the longitudinal tension of the vocal folds, the flow rate, and their prephonatoric position. To facilitate independent control of these parameters, a synthetic larynx model was developed, as detailed in a previous publication.
Methods: This study aims to statistically analyze the influence of airflow and fiber tension on phonation characteristics, such as periodicity and symmetry, glottis closure during vocal fold oscillations, as well as tissue elasticity and generated sound. A total of 76 experiments were conducted and statistically analyzed with a systematic variation of flow rate and longitudinal tension within the vocal folds.During these experiments, vocal fold motion, subglottal pressure, and emitted sound were meticulously measured and analyzed.
Results: Groupwise statistical testing identified the flow rate as the main influencing parameter on nearly all phonation characteristics. However, the fundamental frequency, stiffness parameters, and quality parameters of the primary sound signal are predominantly controlled by the longitudinal tension within the vocal folds.
Discussion: The results demonstrated a complex interplay between the flow rate and tension, resulting in different characteristics of the produced sound signal.
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http://dx.doi.org/10.3389/fphys.2024.1455360 | DOI Listing |
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Univ. Savoie Mont Blanc, CNRS. EDYTEM.
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Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan.
The effect of shape and size of embolic agents on embolization phenomena has been discussed clinically for transcatheter arterial chemoembolization (TACE). We numerically discussed the unique embolization behavior of new deformable toroidal microparticles in blood vessels by computational fluid dynamics simulations. We employed an Eulerian-Eulerian (full Eulerian) fluid-structure interaction (FSI) method to analyze the flow and deformation behaviors of a deformable torus in a cylindrical pipe.
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Department of Pharmaceutics, ShriRam College of Pharmacy, Banmore, Morena-476444, Madhya Pradesh, India.
Tuberculosis (TB) continues to cause significant global mortality, highlighting the need for improved drug delivery systems. The objective of this paper focuses in describing the formulation, optimization and in vivo assessment of rifampicin encapsulated PLGA microparticles for site-specific inhalation therapy. Microparticles for inhalation were produced by spray drying, and the DoE methodology was applied to reach the most suitable aerodynamic properties (mass median aerodynamics diameter (MMAD) 2.
View Article and Find Full Text PDFCochrane Database Syst Rev
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Division of Gastroenterology, Hepatology, and Nutrition, SickKids Research Institute and SickKids Learning Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.
Background: Training in endoscopy has traditionally been based upon an apprenticeship model, where novices develop their skills on real patients under the supervision of experienced endoscopists. In an effort to prioritise patient safety, simulation training has emerged as a means to allow novices to practice in a risk-free environment. This is the second update of the review, which was first published in 2012 and updated in 2018.
View Article and Find Full Text PDFJ Agric Food Chem
September 2025
Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, Athens 15771, Greece.
An innovative 4D targeted method was developed for the determination of 61 bioactive compounds in royal jelly (RJ) related to their health-promoting properties. The method, apart from high-resolution mass spectrometry, exploits the advantages of vacuum-insulated probe-heated electrospray ionization source (VIP-HESI), reducing thermal degradation, and trapped ion mobility spectrometry (TIMS), improving selectivity and compound identification. The optimization of VIP-HESI ionization parameters using experimental designs showed that the critical parameters were the capillary voltage as well as the probe gas flow rate and temperature.
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