Bundled actin structures play an essential role in the mechanical response of the actin cytoskeleton in eukaryotic cells. Although responsible for crucial cellular processes, they are rarely investigated in comparison to single filaments and isotropic networks. Presenting a highly anisotropic structure, the determination of the mechanical properties of individual bundles was previously achieved through passive approaches observing bending deformations induced by thermal fluctuations. We present a new method to determine the bending stiffness of individual bundles, by measuring the decay of an actively induced oscillation. This approach allows us to systematically test anisotropic, bundled structures. Our experiments revealed that thin, depletion force-induced bundles behave as semiflexible polymers and obey the theoretical predictions determined by the wormlike chain model. Thickening an individual bundle by merging it with other bundles enabled us to study effects that are solely based on the number of involved filaments. These thicker bundles showed a frequency-dependent bending stiffness, a behavior that is inconsistent with the predictions of the wormlike chain model. We attribute this effect to internal processes and give a possible explanation with regard to the wormlike bundle theory.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5860748 | PMC |
http://dx.doi.org/10.3390/molecules22101804 | DOI Listing |
Eur J Trauma Emerg Surg
January 2025
Department of Surgical Science, University of Cagliari, Cagliari, Italy.
Background: The current standard of care for mild acute biliary pancreatitis (MABP) involves early laparoscopic cholecystectomy (ELC) to reduce the risk of recurrence. The MANCTRA-1 project revealed a knowledge-to-action gap and higher recurrence rates in patients admitted to medical wards, attributable to fewer ELCs being performed. The project estimated a 35% to 70% probability of narrowing this gap by 2025.
View Article and Find Full Text PDFJ Am Acad Orthop Surg Glob Res Rev
January 2025
From the Department of Orthopaedic Surgery, BronxCare Health System, Bronx, NY.
Background: Rates of emergency department (ED) visits and readmissions after total joint arthroplasty (TJA) have been cited as indicators of TJA quality. Understanding the incidence and nature of these events is critical for prevention. The purpose of this study was to analyze readmission rates 30 and 90 days after TJA at a safety-net hospital in an urban setting and to compare this readmission rate with that for non-safety-net hospitals found in the current literature.
View Article and Find Full Text PDFCurr Med Imaging
January 2025
Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95, Yong An Road, Xicheng District, Beijing 100050, China.
Background: The neuroanatomical basis of white matter fiber tracts in gait impairments in individuals suffering from Parkinson's Disease (PD) is unclear.
Methods: Twenty-four individuals living with PD and 29 Healthy Controls (HCs) were included. For each participant, two-shell High Angular Resolution Diffusion Imaging (HARDI) and high-resolution 3D structural images were acquired using the 3T MRI.
Hum Brain Mapp
January 2025
Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada.
A fundamental issue in neuroscience is a lack of understanding regarding the relationship between brain function and the white matter architecture that supports it. Individuals with chronic neuropathic pain (NP) exhibit functional abnormalities throughout brain networks collectively termed the "dynamic pain connectome" (DPC), including the default mode network (DMN), salience network, and ascending nociceptive and descending pain modulation systems. These functional abnormalities are often observed in a sex-dependent fashion.
View Article and Find Full Text PDFCogn Neurodyn
December 2025
PIT Bioinformatics Group, Eötvös University, Budapest, H-1117 Hungary.
The correlations of several fundamental properties of human brain connections are investigated in a consensus connectome, constructed from 1064 braingraphs, each on 1015 vertices, corresponding to 1015 anatomical brain areas. The properties examined include the edge length, the fiber count, or edge width, meaning the number of discovered axon bundles forming the edge and the occurrence number of the edge, meaning the number of individual braingraphs where the edge exists. By using our previously published robust braingraphs at https://braingraph.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!