The investigation of the mechanical properties of polymer track-etched membranes (TMs) has attracted significant attention in connection with the extended region of their possible applications. In the present work, the mechanical stress fields around the pores of an elongated polyethylene terephthalate TM and around the 0.3 mm holes in model polymer specimens were studied in polarized light and with the finite element method. A break-up experiment showed the controlling role of stress field interaction in the forming of a microcrack system and the generation of a main crack with rupture of the TM (or model pattern). This interaction depended on the relative distance between the pores (holes) and their orientation. The results of the calculations of the pore distribution function over the surface of the TM via the net method and wavelet analysis are presented. The fractal character of pore distribution was established. The geometric characteristics of the TM pore system as initial defects are inherited by obtaining TM-based composites.
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http://dx.doi.org/10.3390/membranes12111168 | DOI Listing |
ACS Nano
January 2025
Department of Orthopedics, The First Affiliated Hospital of Soochow University, 899 Pinghai Road, Soochow, Jiangsu 215000, China.
The extracellular matrix (ECM) stores signaling molecules and facilitates mechanical and biochemical signaling in cells. However, the influence of biomimetic "rejuvenation" ECM structures on aging- and degeneration-related cellular activities and tissue repair is not well understood. We combined physical extrusion and precise "on-off" alternating cross-linking methods to create anisotropic biomaterial microgels (MicroRod and MicroSphere) and explored how they regulate the cell activities of the nucleus pulposus (NP) and their potential antidegenerative effects on intervertebral discs.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Department of Mechanical Engineering & Materials Science, Washington University, St. Louis, Missouri, United States of America.
Cell collectives, like other motile entities, generate and use forces to move forward. Here, we ask whether environmental configurations alter this proportional force-speed relationship, since aligned extracellular matrix fibers are known to cause directed migration. We show that aligned fibers serve as active conduits for spatial propagation of cellular mechanotransduction through matrix exoskeleton, leading to efficient directed collective cell migration.
View Article and Find Full Text PDFDrug Deliv Transl Res
January 2025
School of Pharmacy, Medical Biology Centre, Queen's University Belfast, Belfast, UK.
Glaucoma is an optic neuropathy in which progressive degeneration of retinal ganglion cells and the optic nerve leads to irreversible visual loss. Glaucoma is one of the leading causes of blindness. The pathogenesis of glaucoma is determined by different pathogenetic mechanisms, including increased intraocular pressure, mechanical stress, excitotoxicity, resistance to aqueous drainage and oxidative stress.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Institute of Hydrogen Technology, Helmholtz-Zentrum Hereon, Geesthacht, Germany.
Coherent phase transformations in interstitial solid solutions or intercalation compounds with a miscibility gap are of practical relevance for energy storage materials and specifically for metal hydride or lithium-ion compound nanoparticles. Different conclusions on the size-dependence of the transformation conditions are reached by modeling or theory focusing on the impact of either one (internal, solid-state-) critical-point wetting of the nanoparticle surface or coherency constraints from solute-saturated surface layers. We report a hybrid numerical approach, combining atomistic grand canonical Monte Carlo simulation with a continuum mechanics analysis of coherency stress and modeling simultaneously wetting and mechanical constraints.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
University of Minnesota Duluth, Duluth, MN, USA.
Background: Regulated breathing is increasingly recognized as a vital component in enhancing cognition. Scientific studies suggest that intentional and controlled breathing techniques, such as deep and rhythmic breathing, can promote relaxation, reduce stress, and improve oxygen flow to the brain [1, 2]. Consequently, this may contribute to heightened cognitive function, better concentration, and increased mental clarity, accentuating the importance of incorporating mindful breathing practices as a potential avenue for cognitive improvement [3].
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