A mathematical model for heating and cooling during hyperthermia has been developed from an appropriate solution of a bioheat transfer equation. Predicted cooling rates obtained from the model have been compared with cooling rates obtained from experiments performed on both perfused and non-perfused normal canine brain tissue. The agreement between the predicted and observed cooling rates in non-perfused tissue is satisfactory (within 6-11 per cent) and provides confidence that the conduction process is being accurately represented. The model is then used to estimate the relative contribution of conductive and convective (blood flow) heat loss during cooling for the in vivo experiments. Estimates of blood flow dynamics are made from cooling data taken early and late in a heating course using the model to correct for conductive heat loss. Simplified forms of the bioheat transfer equation are examined. An adequate model for the observed cooling data is one that treats heat loss (both conduction and blood flow) as a heat sink (i.e. an effective perfusion model) rather than an effective thermal conductivity model.
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http://dx.doi.org/10.3109/02656738909140451 | DOI Listing |
Plant Physiol
December 2024
Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 00 Prague 6, Czech Republic.
Pollen germination and pollen tube (PT) growth are extremely sensitive to high temperatures. During heat stress (HS), global translation shuts down and favors the maintenance of the essential cellular proteome for cell viability and protection against protein misfolding. Here, we demonstrate that under normal conditions, the Arabidopsis (Arabidopsis thaliana) eukaryotic translation initiation factor subunit eif3m1/eif3m2 double mutant exhibits poor pollen germination, loss of PT integrity and an increased rate of aborted seeds.
View Article and Find Full Text PDFPLoS Biol
January 2025
Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan.
The unique architecture of the liver consists of hepatic lobules, dividing the hepatic features of metabolism into 2 distinct zones, namely the pericentral and periportal zones, the spatial characteristics of which are broadly defined as metabolic zonation. R-spondin3 (Rspo3), a bioactive protein promoting the Wnt signaling pathway, regulates metabolic features especially around hepatic central veins. However, the functional impact of hepatic metabolic zonation, regulated by the Rspo3/Wnt signaling pathway, on whole-body metabolism homeostasis remains poorly understood.
View Article and Find Full Text PDFMicrob Biotechnol
January 2025
Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain.
Sterol composition plays a crucial role in determining the ability of yeast cells to withstand high temperatures, an essential trait in biotechnology. Using a targeted evolution strategy involving fluconazole (FCNZ), an inhibitor of the sterol biosynthesis pathway, and the immunosuppressant FK506, we aimed to enhance thermotolerance in an industrial baker's yeast population by modifying their sterol composition. This approach yielded six isolates capable of proliferating in liquid YPD with μ values ranging from 0.
View Article and Find Full Text PDFIntroduction: Space agencies will embark on manned journeys to Mars on smaller vehicles than those used previously. In-flight exercise on those flights must abate the adverse effects microgravity (μG) has on humans. Due to space constraints on these vehicles, a single exercise device must address multiple fitness needs.
View Article and Find Full Text PDFFront Public Health
January 2025
Shandong Academy of Chinese Medicine, Jinan, China.
Background: Night sweats are a condition in which an individual sweats excessively during sleep without awareness, and stops when they wake up. Prolonged episodes of night sweats might result in the depletion of trace elements and nutrients, affecting the growth and development of children.
Purpose: To investigate the relationship between sweat nights and season.
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