Animal models are commonly used to test the efficacy of impact loading regimens on bone strength. We designed an inexpensive force platform to concurrently measure the separate peak vertical impact forces produced by the fore and hindfeet of immature F-344 rats when dropped onto the platform. The force platform consisted of three load cells placed in a triangular pattern under a flat plate. Rats were dropped from heights of 30, 45 and 60 cm onto the platform so that they landed on all four feet concurrently. The peak vertical impact forces produced by the feet of the rats were measured using a sampling frequency of 100 kHz. The location of each foot at landing relative to the load cells, and the force received by each load cell were combined in a series of static equations to solve for the vertical impact forces produced by the fore and hindfeet. The forces produced by feet when rats stood on the single platform were similarly determined. The forces exerted separately by the fore and hindfeet of young rats when landing on the plate as a ratio to standing forces were then calculated. Rats when standing bore more weight on their hindfeet but landed with more weight on their forefeet, which provides rationale for the greater response to landing forces of bones in the forelimbs than those in the hindlimbs. This system provided a useful method to simultaneously measure peak vertical impact forces in fore and hindfeet in rats.
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http://dx.doi.org/10.1016/j.jbiomech.2009.08.002 | DOI Listing |
Polymers (Basel)
January 2025
Faculty of Mechanics, University Politehnica of Timisoara, Piata Victoriei 2, 300006 Timisoara, Romania.
This study investigated silicone composites with distributed boron nitride platelets and carbon microfibers that are oriented electrically. The process involved homogenizing and dispersing nano/microparticles in the liquid polymer, aligning the particles with DC and AC electric fields, and curing the composite with IR radiation to trap particles within chains. This innovative concept utilized two fields to align particles, improving the even distribution of carbon microfibers among BN in the chains.
View Article and Find Full Text PDFChildren (Basel)
January 2025
Research Laboratory, Exercise Physiology and Physiopathology: From Integrated to Molecular "Biology, Medicine and Health" (LR19ES09), Faculty of Medicine of Sousse, University of Sousse, Sousse 4000, Tunisia.
Objectives: There is a lack of studies that investigate the relationship between anthropometric profiles, biological maturity, and specific physical performances in young male basketball players. This study aimed to evaluate the development of anthropometric characteristics and physical performance across different age and maturity groups among male basketball players in Palestine, as well as to identify the anthropometric factors influencing physical performance within this population.
Methods: A total of one-hundred-fifty male basketball players, aged 12 to 16, participated in this study.
Biomedicines
January 2025
Department of Pathophysiology, Albert Szent-Györgyi Medical School, University of Szeged, Szőkefalvi-Nagy Béla str. 6., 6720 Szeged, Hungary.
Ghrelin and growth hormone-releasing peptide 6 (GHRP-6) are peptides which can stimulate GH release, acting through the same receptor. Ghrelin and its receptor have been involved in reward sensation and addiction induced by natural and artificial drugs, including nicotine. The present study aimed to investigate the impacts of ghrelin and GHRP-6 on the horizontal and vertical activity in rats exposed to chronic nicotine treatment followed by acute nicotine withdrawal.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Astronomy, Astrophysics and Space Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453552, India.
Arctic precipitation plays a crucial role in shaping the surface mass balance of Arctic sea ice and has wide-ranging impacts on local climate, ecosystems, and global sea level dynamics. With the Arctic undergoing warming trends, historical data and climate models indicate a shift from primarily snowfall to a rise in liquid and mixed forms of precipitation. This study tried to explain the microphysical characteristics and atmospheric conditions associated with different forms of precipitation and their transitions.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), College of Chemistry, Sichuan University, Chengdu 610064, China.
The development of bio-based flame retardants has garnered significant attention, however, significant challenges remain in achieving efficient flame retardancy and eco-friendly preparation methods. Herein, we propose a facile, atomic-efficient, and eco-friendly strategy for synthesizing a trinity chitosan-based flame retardant, phosphite-protonated chitosan (PCS). The chemical structure was systematically analyzed and the impact of varying degrees of protonation on the dissolution behavior and rheological properties were investigated.
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