1,720,962 research outputs found
THE RESPONSE OF ENDOTHELIAL CELLS TO ANGIOGENIC STIMULI: EXPERIMENTS, MODELING, AND SIMULATIONS
Full text linkTHE RESPONSE OF ENDOTHELIAL CELLS TO ANGIOGENIC STIMULI: EXPERIMENTS, MODELING, AND SIMULATIONSTHE RESPONSE OF ENDOTHELIAL CELLS TO ANGIOGENIC STIMULI: EXPERIMENTS, MODELING, AND SIMULATION
A Comparative Review of Models for All-Solid-State Li-Ion Batteries
Full text linkIn recent times, there has been significant enthusiasm for the development of all-solid-state Li-ion batteries. This interest stems from a dual focus on safety—addressing concerns related to toxic and flammable organic liquid electrolytes—and the pursuit of high energy density. While liquid electrolyte batteries currently constitute the vast majority of commercial cells, solid electrolyte batteries show great promise. In parallel with experimental research, computational models clarify several fundamental physics that take place throughout battery operations. Giving up on reviewing a broad screening of the existing literature, we set out to select here a few highly relevant models, emphasizing some fundamental conceptual advancements and offering an in-depth and critical insight into the current state of the art. The papers we selected aim at providing the reader with a tangible and quantitative understanding of how all-solid-state Li-ion batteries operate, including the different mechanisms at play and the mathematical tools required to model the pertinent physics and mechanics
Modeling Receptor Motility along Advecting Lipid Membranes
No full textThis work aims to overview multiphysics mechanobiological computational models for receptor dynamics along advecting cell membranes. Continuum and statistical models of receptor motility are the two main modeling methodologies identified in reviewing the state of the art. Within the former modeling class, a further subdivision based on different biological purposes and processes of proteins’ motion is recognized; cell adhesion, cell contractility, endocytosis, and receptor relocations on advecting membranes are the most relevant biological processes identified in which receptor motility is pivotal. Numerical and/or experimental methods and approaches are highlighted in the exposure of the reviewed works provided by the literature, pertinent to the topic of the present manuscript. With a main focus on the continuum models of receptor motility, we discuss appropriate multiphyisics laws to model the mass flux of receptor proteins in the reproduction of receptor relocation and recruitment along cell membranes to describe receptor–ligand chemical interactions, and the cell’s structural response. The mass flux of receptor modeling is further supported by a discussion on the methodology utilized to evaluate the protein diffusion coefficient developed over the years
On the generation of force required for actin-based motility
Full text linkAbstract The fundamental question of how forces are generated in a motile cell, a lamellipodium, and a comet tail is the subject of this note. It is now well established that cellular motility results from the polymerization of actin, the most abundant protein in eukaryotic cells, into an interconnected set of filaments. We portray this process in a continuum mechanics framework, claiming that polymerization promotes a mechanical swelling in a narrow zone around the nucleation loci, which ultimately results in cellular or bacterial motility. To this aim, a new paradigm in continuum multi-physics has been designed, departing from the well-known theory of Larché–Cahn chemo-transport-mechanics. In this note, we set up the theory of network growth and compare the outcomes of numerical simulations with experimental evidence
Insights on the receptor dynamics during the spreading of endothelial cells
No full textMulti-physics interactions preside the ligand-dependent relocation of the vascular endothelial
cell (VEGFR2) receptor in the lipid membrane of endothelial cells (ECs) [1–
3]. In spite using a surrogated mechanics allowed identifying limiting factors of the
evolution in time of quantities of interest with significant accuracy, the quantification
of mechanical measures remained questionable.
In the present work, VEGFR2 receptor dynamics is coupled to large strain mechanics
to simulate the relocation of proteins on endothelial cells. Fully coupled mass and momentum
balance laws, accompanied by thermodynamically derived constitutive laws,
are written in weak form and discretized via the finite element method. High performance
computations are carried out afterwards, making use of the open-source library
deal.ii (dealii.org).
In vitro ECs adhesion assay on a Poly-Lysine substrate validated the numerical simulations.
Poly-Lysine is a positively charged amino acid polymer. Poly-Lysine promotes
cell adhesion to solid substrates by enhancing electrostatic interaction between negatively
charged ions of the cell membrane in the absence of the cytoskeleton assembly.
We developed a mechanical models for the geometrical evolution of the cell membrane
in the absence of cytoskeleton reorganization, accounting for the passive mechanical
response of the cell only. This selective, co-designed approach in experiments and
modeling allows shading new insights on both the receptor dynamics and the physical
mechanisms that govern cell adhesion and spreading
Mechanics of Batteries
No full textThis chapter centers on the modeling of materials for energy storage, with a specific focus on Li-ion and Na-ion batteries. Theoretical and computational analyses not only enhance our understanding of how actual batteries behave under various conditions but also have the potential to guide the development of new materials and innovative architectures in conjunction with experimental approaches. Thus, modeling can significantly contribute to the design and prediction of the lifespan of energy storage materials and devices. Batteries exhibit inherent multi-physics and multi-scale characteristics in both space and time. We aim to investigate the mechanical aspects encompassed by multi-physics modeling concepts, methodologies, and simulations at varying scales. In this chapter, we will review the fundamental components of a state-of-the-art electrolytic cell, define their purpose, operational functioning, and mechanical response accounting for various classes of materials
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A coupled model of transport-reaction-mechanics with trapping, Part II: Large strain analysis
Full text linkA coupled finite strain chemo-transport-mechanical formulation with trapping is here proposed to extend a previous work set in the realm of small strain theory in continuum mechanics. The theory is rooted in non-equilibrium rational thermodynamics. The kinematics is based on a multiplicative decomposition of the deformation gradient to account for swelling and shrinking, thermal, elastic and inelastic contributions. Mass balance laws and balance of linear and angular momentum, as well as the laws of thermodynamics for a convecting body, are directly formulated in their material description, after specifications of some standard transformation rules between current and reference configuration. Thermodynamic restrictions are identified based on the functional dependence of the referential Helmholtz free energy density, which is chosen as the thermodynamic potential, and further subjected to a constitutive additive decomposition. Constitutive prescriptions for the chemical potentials, referential heat and mass fluxes, chemical kinetics and the generalized heat equation lead to the establishment of the governing equations. The theoretical framework is complemented by numerical simulations, highlighting the potential of the proposed formulation in multi-physics applications
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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