Scintigraphic data are provided for 20 normal control subjects, 39-65 years of age. Each subject swallowed 10 cc of water and 10 cc of a more viscous material (1,100 centipoise) consisting of apple juice thickened with Thick-It, a commercial food thickener. The test substances were combined with 2.5 mCi Tc-99m sulfur colloid. Scintigraphic data were acquired in dynamic mode for 10 sec at 25 frames/sec as the subject swallowed. Time-activity (TA) data were used to compute transit times, percentage residues in the mouth and pharynx, percent ingested, and a derived swallow efficiency score. The liquid was ingested in a single swallow by all subjects, and 9 cc was actually transferred to the esophagus. In contrast, for the viscous material, 11/20 subjects performed a second clearing swallow within the 10-sec interval. On the first swallow with the viscous substance, an average of 7 cc was transferred to the esophagus. Scintigraphy offers an excellent technique for determining natural and preferred volumes for swallowing a variety of bolus consistencies, since it can quantify the volume of each swallow or partial swallow. In this group of subjects the oral discharge time was shorter with the viscous material than with the water, but the pharyngeal transit times were not significantly different for the two bolus consistencies. Numerical efficiency scores were lower for the viscous material, indicating that such a measure is bolus dependent.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/BF00385799 | DOI Listing |
J Nonlinear Sci
January 2025
Robotics and Mechatronics Department, University of Twente, Enschede, The Netherlands.
In this paper, we present a novel approach to the geometric formulation of solid and fluid mechanics within the port-Hamiltonian framework, which extends the standard Hamiltonian formulation to non-conservative and open dynamical systems. Leveraging Dirac structures, instead of symplectic or Poisson structures, this formalism allows the incorporation of energy exchange within the spatial domain or through its boundary, which allows for a more comprehensive description of continuum mechanics. Building upon our recent work in describing nonlinear elasticity using exterior calculus and bundle-valued differential forms, this paper focuses on the systematic derivation of port-Hamiltonian models for solid and fluid mechanics in the material, spatial, and convective representations using Hamiltonian reduction theory.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, Research Institute of Aero-Engine, Beihang University, Beijing 100191, China. Electronic address:
Hypothesis: Complex emulsions usually consist of aqueous phases, like oil-in-water-in-oil (o/w/o) and water-in-oil-in-water (w/o/w), serving foundational roles in colloid science. Oil-in-oil-oil (o/o/o) emulsions offer new avenues for non-aqueous reagents but face challenges in balancing the forces between multiple organic phases.
Experiments: In this work, we generate o/o/o emulsions by integrating an AC electric field with a double cross-junction microchannel.
ACS Appl Mater Interfaces
January 2025
Department of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Developing damping materials that are both optically transparent and mechanically robust, while offering broad frequency damping capacity, is a significant challenge─particularly for devices that require protection without compromising visual clarity. Conventional methods often either fail to maintain transparency or involve complex designs that are difficult to implement. Here, we present an ionogel system that integrates a physically cross-linked elastic copolymer network with a viscous ionic liquid.
View Article and Find Full Text PDFIn Vitro Model
June 2024
Department of Pharmacy, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH UK.
Unlabelled: Wound debridement is commonplace in expediting wound healing in the clinic. Despite this, there are limited resources available for simulation training for practitioners prior to facing real-life patients. Typically, citrus peels or porcine skin are employed in a vain attempt to improve debridement proficiency, yet these fail to provide a realistic experience of the textures and consistencies of wounds.
View Article and Find Full Text PDFPRX Life
June 2024
Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Biomolecular condensates are dynamic intracellular entities defined by their sequence- and composition-encoded material properties. During aging, these properties can change dramatically, potentially leading to pathological solidlike states, the mechanisms of which remain poorly understood. Recent experiments reveal that the aging of condensates involves a complex interplay of solvent depletion, strengthening of sticker links, and the formation of rigid structural segments such as beta fibrils.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!