scholarly journals Modelling fluid deformable surfaces with an emphasis on biological interfaces

2019 ◽  
Vol 872 ◽  
pp. 218-271 ◽  
Author(s):  
Alejandro Torres-Sánchez ◽  
Daniel Millán ◽  
Marino Arroyo
Keyword(s):  
Lipid Bilayers ◽  
Three Dimensional ◽  
Power Input ◽  
Cell Cortex ◽  
Stiff System ◽  
Cell Sheets ◽  
Deformable Surfaces ◽  
Ale Formulation ◽  
Eulerian Descriptions ◽  
Treat All

Fluid deformable surfaces are ubiquitous in cell and tissue biology, including lipid bilayers, the actomyosin cortex or epithelial cell sheets. These interfaces exhibit a complex interplay between elasticity, low Reynolds number interfacial hydrodynamics, chemistry and geometry, and govern important biological processes such as cellular traffic, division, migration or tissue morphogenesis. To address the modelling challenges posed by this class of problems, in which interfacial phenomena tightly interact with the shape and dynamics of the surface, we develop a general continuum mechanics and computational framework for fluid deformable surfaces. The dual solid–fluid nature of fluid deformable surfaces challenges classical Lagrangian or Eulerian descriptions of deforming bodies. Here, we extend the notion of arbitrarily Lagrangian–Eulerian (ALE) formulations, well-established for bulk media, to deforming surfaces. To systematically develop models for fluid deformable surfaces, which consistently treat all couplings between fields and geometry, we follow a nonlinear Onsager formalism according to which the dynamics minimizes a Rayleighian functional where dissipation, power input and energy release rate compete. Finally, we propose new computational methods, which build on Onsager’s formalism and our ALE formulation, to deal with the resulting stiff system of higher-order partial differential equations. We apply our theoretical and computational methodology to classical models for lipid bilayers and the cell cortex. The methods developed here allow us to formulate/simulate these models in their full three-dimensional generality, accounting for finite curvatures and finite shape changes.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

An Update on Recent Advances in Cubosome: A Novel Drug Delivery System

2021 ◽  
Vol 21 ◽  
Author(s):  
Madhukar Garg ◽  
Anju Goyal ◽  
Sapna Kumari
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Lipid Bilayers ◽  
Delivery System ◽  
Liquid Crystalline ◽  
Three Dimensional ◽  
Biologically Active ◽  
Potential Applications ◽  
Health Related ◽  
Novel Drug

: Cubosomes are highly stable nanostructured liquid crystalline dosage delivery form derived from amphiphilic lipids and polymer-based stabilizers converting it in a form of effective biocompatible carrier for the drug delivery. The delivery form comprised of bicontinuous lipid bilayers arranged in three dimensional honeycombs like structure provided with two internal aqueous channels for incorporation of number of biologically active ingredients. In contrast liposomes they provide large surface area for incorporation of different types of ingredients. Due to the distinct advantages of biocompatibility and thermodynamic stability, cubosomes have remained the first preference as method of choice in the sustained release, controlled release and targeted release dosage forms as new drug delivery system for the better release of the drugs. As lot of advancement in the new form of dosage form has bring the novel avenues in drug delivery mechanisms so it was matter of worth to compile the latest updates on the various aspects of mentioned therapeutic delivery system including its structure, routes of applications along with the potential applications to encapsulate variety drugs to serve health related benefits.

Fabrication of three-dimensional tissues with multilayer mesenchymal stem cell sheets: overcoming the diffusion limit

2008 ◽  
Vol 9 (2) ◽  
pp. 110 ◽  
Author(s):  
W Matsuda ◽  
Y Haraguchi ◽  
T Shimizu ◽  
S Miyoshi ◽  
A Umezawa ◽  
...  
Keyword(s):  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Three Dimensional ◽  
Diffusion Limit ◽  
Cell Sheets

Abstract 020: Cell-sheet-based Bioengineered Human Cardiac Tissue Using Pluripotent Stem Cells For Heart Repair And Disease Models

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Katsuhisa Matsuura ◽  
Tatsuya Shimizu ◽  
Nobuhisa Hagiwara ◽  
Teruo Okano
Keyword(s):  
Cardiac Tissue ◽  
Subcutaneous Tissue ◽  
Cell Sheet ◽  
Three Dimensional ◽  
Embryoid Bodies ◽  
Cardiac Differentiation ◽  
Cardiac Cell ◽  
Cell Sheets ◽  
High Efficient ◽  
Human Cardiac Tissue

We have developed an original scaffold-free tissue engineering approach, “cell sheet engineering”, and this technology has been already applied to regenerative medicine of various organs including heart. As the bioengineered three-dimensional cardiac tissue is expected to not only function for repairing the broad injured heart but also to be the practicable heart tissue models, we have developed the cell sheet-based perfusable bioengineered three-dimensional cardiac tissue. Recently we have also developed the unique suspension cultivation system for the high-efficient cardiac differentiation of human iPS cells. Fourteen-day culture with the serial treatments of suitable growth factors and a small compound in this stirring system with the suitable dissolved oxygen concentration produced robust embryoid bodies that showed the spontaneous beating and were mainly composed of cardiomyocytes (~80%). When these differentiated cells were cultured on temperature-responsive culture dishes after the enzymatic dissociation, the spontaneous and synchronous beating was observed accompanied with the intracellular calcium influx all over the area even after cell were detached from culture dishes as cell sheets by lowering the culture temperature. The cardiac cell sheets were mainly composed of cardiomyocytes (~80%) and partially mural cells (~20%). Furthermore, extracellular action potential propagation was observed between cell sheets when two cardiac cell sheets were partially overlaid, and this propagation was inhibited by the treatment with some anti-arrhythmic drugs. When the triple layered cardiac tissue was transplanted onto the subcutaneous tissue of nude rats, the spontaneous pulsation was observed over 2 months and engrafted cardiomyocytes were vascularized with the host tissue-derived endothelial cells. These findings suggest that cardiac cell sheets formed by hiPSC-derived cardiomyocytes might have sufficient properties for the creation of thickened cardiac tissue. Now we are developing the vascularized thickened human cardiac tissue by the repeated layering of cardiac cell sheets on the artificial vascular bed in vitro.

scholarly journals A Useful Manufacturing Guide for Rotary Piercing Seamless Pipe by ALE Method

2020 ◽  
Vol 8 (10) ◽  
pp. 756
Author(s):  
Ameen Topa ◽  
Burak Can Cerik ◽  
Do Kyun Kim
Keyword(s):  
Numerical Simulations ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Material Model ◽  
Manufacturing Processes ◽  
Arbitrary Lagrangian Eulerian ◽  
Analysis Method ◽  
Seamless Pipe ◽  
Ale Formulation ◽  
Good Agreement

The development of numerical simulations is potentially useful in predicting the most suitable manufacturing processes and ultimately improving product quality. Seamless pipes are manufactured by a rotary piercing process in which round billets (workpiece) are fed between two rolls and pierced by a stationary plug. During this process, the material undergoes severe deformation which renders it impractical to be modelled and analysed with conventional finite element methods. In this paper, three-dimensional numerical simulations of the piercing process are performed with an arbitrary Lagrangian–Eulerian (ALE) formulation in LS-DYNA software. Details about the material model as well as the elements’ formulations are elaborated here, and mesh sensitivity analysis was performed. The results of the numerical simulations are in good agreement with experimental data found in the literature and the validity of the analysis method is confirmed. The effects of varying workpiece velocity, process temperature, and wall thickness on the maximum stress levels of the product material/pipes are investigated by performing simulations of sixty scenarios. Three-dimensional surface plots are generated which can be utilized to predict the maximum stress value at any given combination of the three parameters.

scholarly journals Nanogold as a Specific Marker for Electron Cryotomography

2009 ◽  
Vol 15 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Yongning He ◽  
Grant J. Jensen ◽  
Pamela J. Bjorkman
Keyword(s):  
Lipid Bilayers ◽  
Outer Surface ◽  
Three Dimensional ◽  
Fc Receptor ◽  
Specific Marker ◽  
Neonatal Fc Receptor ◽  
Membrane Bound ◽  
Nanogold Particles ◽  
Intracellular Vesicles ◽  
Electron Cryotomography

AbstractWhile electron cryotomography (ECT) provides “molecular” resolution, three-dimensional images of unique biological specimens, sample crowdedness, and/or resolution limitations can make it difficult to identify specific macromolecular components. Here we used a 1.4 nm Nanogold® cluster specifically attached to the Fc fragment of IgG to monitor its interaction with the neonatal Fc receptor (FcRn), a membrane-bound receptor that transports IgG across cells in acidic intracellular vesicles. ECT was used to image complexes formed by Nanogold-labeled Fc bound to FcRn attached to the outer surface of synthetic liposomes. In the resulting three-dimensional reconstructions, 1.4 nm Nanogold particles were distributed predominantly along the interfaces where 2:1 FcRn-Fc complexes bridged adjacent lipid bilayers. These results demonstrate that the 1.4 nm Nanogold cluster is visible in tomograms of typically thick samples (∼250 nm) recorded with defocuses appropriate for large macromolecules and is thus an effective marker.

Effect of system compliance on weld power in ultrasonic additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gowtham Venkatraman ◽  
Adam Hehr ◽  
Leon M. Headings ◽  
Marcelo J. Dapino
Keyword(s):  
Additive Manufacturing ◽  
Electrical Power ◽  
Three Dimensional ◽  
Power Input ◽  
Material Strength ◽  
Content Type ◽  
Ultrasonic Additive Manufacturing ◽  
Linear Elastic ◽  
Mechanical Compliance ◽  
The Relationship

Purpose Ultrasonic additive manufacturing (UAM) is a solid-state joining technology used for three-dimensional printing of metal foilstock. The electrical power input to the ultrasonic welder is a key driver of part quality in UAM, but under the same process parameters, it can vary widely for different build geometries and material combinations because of mechanical compliance in the system. This study aims to model the relationship between UAM weld power and system compliance considering the workpiece (geometry and materials) and the fixture on which the build is fabricated. Design/methodology/approach Linear elastic finite element modeling and experimental modal analysis are used to characterize the system’s mechanical compliance, and linear system dynamics theory is used to understand the relationship between weld power and compliance. In-situ measurements of the weld power are presented for various build stiffnesses to compare model predictions with experiments. Findings Weld power in UAM is found to be largely determined by the mechanical compliance of the build and insensitive to foil material strength. Originality/value This is the first research paper to develop a predictive model relating UAM weld power and the mechanical compliance of the build over a range of foil combinations. This model is used to develop a tool to determine the process settings required to achieve a consistent weld power in builds with different stiffnesses.

scholarly journals 3D Numerical Simulation of Seamless Pipe Piercing Process by Fluid-Structure Interaction Method

2018 ◽  
Vol 203 ◽  
pp. 06016 ◽  
Author(s):  
Ameen Topa ◽  
Do Kyun Kim ◽  
Youngtae Kim
Keyword(s):  
Numerical Simulations ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Rolling Process ◽  
Arbitrary Lagrangian Eulerian ◽  
Analysis Method ◽  
Seamless Pipe ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Ale Formulation

Seamless pipes are produced using piercing rolling process in which round bars are fed between two rolls and pierced by stationary plug. During this process, the material undergoes severe deformation which renders it impractical to perform the numerical simulations with conventional finite element methods. In this paper, three dimensional numerical simulations of the piercing process are performed with Fluid-Structure Interaction (FSI) Method using Arbitrary Lagrangian-Eulerian (ALE) Formulation with LS DYNA software. The results of numerical simulations agree with experimental data of Plasticine workpiece and the validity of the analysis method is confirmed.

scholarly journals A fully consistent and conservative vertically adaptive coordinate system for SLIM 3D v0.4, a DG finite element hydrodynamic model, with an application to the thermocline oscillations of Lake Tanganyika

2017 ◽  
Author(s):  
Philippe Delandmeter ◽  
Jonathan Lambrechts ◽  
Vincent Legat ◽  
Valentin Vallaeys ◽  
Jaya Naithani ◽  
...  
Keyword(s):  
Finite Element ◽  
Lake Tanganyika ◽  
Three Dimensional ◽  
Adaptive Mesh ◽  
Vertical Movement ◽  
Finite Difference Schemes ◽  
Arbitrary Lagrangian Eulerian ◽  
Vertical Diffusion ◽  
Continuity Equations ◽  
Ale Formulation

Abstract. The discontinuous Galerkin (DG) finite element method is well suited to the modelling, with a relatively small number of elements, of three-dimensional flows exhibiting strong velocity or density gradients. Its performance can be highly enhanced by having recourse to r-adaptivity. Here, a vertical adaptive mesh method is developed for DG finite elements. This method, originally designed for finite difference schemes, is based on the vertical diffusion of the mesh nodes, with the diffusivity controlled by the density jumps at the mesh element interfaces. The mesh vertical movement is determined by means of a conservative Arbitrary Lagrangian–Eulerian (ALE) formulation. Though conservativity is naturally achieved, tracer consistency is obtained by a suitable construction of the mesh vertical velocity field, which is defined in such a way that it is fully compatible with the tracer and continuity equations at a discrete level. The vertically adaptive mesh approach is implemented in the geophysical and environmental flow model SLIM 3D (www.climate.be/slim). Idealised benchmarks, aimed at simulating the oscillations of a sharp thermocline, are dealt with. Then, the relevance of the vertical adaptivity technique is assessed by simulating thermocline oscillations of Lake Tanganyika. The results are compared to measured vertical profiles of temperature, showing similar stratification and outcropping events.

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