A long-standing issue in the area of granular media is the tail of the force distribution, in particular, whether this is exponential, Gaussian, or even some other form. Here we resolve the issue for the case of the force network ensemble in two dimensions. We demonstrate that conservation of the total area of a reciprocal tiling, a direct consequence of local force balance, is crucial for predicting the local stress distribution. Maximizing entropy while conserving the tiling area and total pressure leads to a distribution of local pressures with a generically Gaussian tail that is in excellent agreement with numerics, both with and without friction and for two different contact networks.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.100.238001 | DOI Listing |
Metabolomics
January 2025
Laboratory of Applied Mass Spectrometry, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
Introduction: Hemodynamic forces play a crucial role in modulating endothelial cell (EC) behavior, significantly influencing blood vessel responses. While traditional in vitro studies often explore ECs under static conditions, ECs are exposed to various hemodynamic forces in vivo. This study investigates how wall shear stress (WSS) influences EC metabolism, focusing on the interplay between WSS and key metabolic pathways.
View Article and Find Full Text PDFAlchemical free energy methods using molecular mechanics (MM) force fields are essential tools for predicting thermodynamic properties of small molecules, especially via free energy calculations that can estimate quantities relevant for drug discovery such as affinities, selectivities, the impact of target mutations, and ADMET properties. While traditional MM forcefields rely on hand-crafted, discrete atom types and parameters, modern approaches based on graph neural networks (GNNs) learn continuous embedding vectors that represent chemical environments from which MM parameters can be generated. Excitingly, GNN parameterization approaches provide a fully end-to-end differentiable model that offers the possibility of systematically improving these models using experimental data.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 30050, Taiwan, ROC.
Here, we report the design, synthesis, and comprehensive characterization of the bis-cholesterol supramolecular gelator, which contains photochromic stiff-stilbene as a bridging unit. The -isomer of stiff-stilbene bridged bis-cholesterol (-) was first synthesized with a systematic design, which can be further converted into its -isomer (-) with a high degree of efficiency (ca. 100%) upon exposure to 385 nm UV light.
View Article and Find Full Text PDFBiomaterials
January 2025
Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA. Electronic address:
The mechanical properties of the extracellular matrix critically regulate stem cell differentiation in 3D. Alginate hydrogels with tunable bulk stiffness and viscoelasticity can modulate differentiation in 3D through mechanotransduction. Such enhanced differentiation is correlated with changes in the local matrix compliance- the extent of matrix deformation under applied load.
View Article and Find Full Text PDFNucleus
December 2025
Department of Physiology and Biophysics, The University of Illinois at Chicago - College of Medicine, Chicago, IL, USA.
The vascular network, uniquely sensitive to mechanical changes, translates biophysical forces into biochemical signals for vessel function. This process relies on the cell's architectural integrity, enabling uniform responses to physical stimuli. Recently, the nuclear envelope (NE) has emerged as a key regulator of vascular cell function.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!