Channel Geometry Effects on Red Blood Cell Dynamics and the Resulting ATP Release

2010 ◽  
Author(s):  
Alison M. Forsyth ◽  
Philip D. Owrutsky ◽  
Jiandi Wan ◽  
Howard A. Stone
Keyword(s):  
High Speed ◽  
Cell Tracking ◽  
Enzymatic Reaction ◽  
Atp Release ◽  
Microfluidic Channels ◽  
Dynamical Response ◽  
Functional Difference ◽  
Cell Dynamics ◽  
Dynamic Behaviors ◽  
Cell Behaviors

In shear flow, red blood cells (RBCs) exhibit a variety of dynamic behaviors such as translation, tumbling, swinging, and tank-treading. The physiological consequences of these dynamic behaviors, however, are unknown. For example, how different cell dynamics, be it translation, tumbling, or tank-treading relate to ATP release and how these dynamics are altered by pathological geometries such as constrictions and plaque formations at asymmetric bifurcations are not known. Using microfluidic channels to mimic pathological geometries and RBCs with attached carboxylate beads, to follow any relevant motion, we are able to quantify the dynamical response of red cells to specific pathological geometries with in vitro models. Further, by using an ATP-luciferase enzymatic reaction we set out to determine if there is a functional difference, via chemical release, in cell behaviors. Previously, we correlated RBC deformation and ATP release (Wan et al, PNAS 2008) which in vivo is known to stimulate nitric oxide production, leading to vasodilation. High-speed video and a probability-based cell tracking algorithm make it possible to study large numbers of cells. Preliminary experiments have shown that when cells enter a constriction, there are increased instances of tumbling along constriction wall, while cells more central in the constriction are aligned and deformed by the entrance flow. The relation between the observed cell behaviors and resulting ATP release will be reported.

scholarly journals High-speed panoramic light-sheet microscopy reveals global endodermal cell dynamics

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Benjamin Schmid ◽  
Gopi Shah ◽  
Nico Scherf ◽  
Michael Weber ◽  
Konstantin Thierbach ◽  
...  
Keyword(s):  
High Speed ◽  
Light Sheet ◽  
Endodermal Cell ◽  
Cell Dynamics ◽  
Light Sheet Microscopy

scholarly journals Data-driven modeling reveals cell behaviors controlling self-organization during Myxococcus xanthus development

2017 ◽  
Vol 114 (23) ◽  
pp. E4592-E4601 ◽  
Author(s):  
Christopher R. Cotter ◽  
Heinz-Bernd Schüttler ◽  
Oleg A. Igoshin ◽  
Lawrence J. Shimkets
Keyword(s):  
Cell Tracking ◽  
Myxococcus Xanthus ◽  
Cell Movement ◽  
Modeling Method ◽  
Data Driven ◽  
Self Organization ◽  
Emergent Properties ◽  
Developmental Cycle ◽  
Fluorescent Cell ◽  
Cell Behaviors

Collective cell movement is critical to the emergent properties of many multicellular systems, including microbial self-organization in biofilms, embryogenesis, wound healing, and cancer metastasis. However, even the best-studied systems lack a complete picture of how diverse physical and chemical cues act upon individual cells to ensure coordinated multicellular behavior. Known for its social developmental cycle, the bacterium Myxococcus xanthus uses coordinated movement to generate three-dimensional aggregates called fruiting bodies. Despite extensive progress in identifying genes controlling fruiting body development, cell behaviors and cell–cell communication mechanisms that mediate aggregation are largely unknown. We developed an approach to examine emergent behaviors that couples fluorescent cell tracking with data-driven models. A unique feature of this approach is the ability to identify cell behaviors affecting the observed aggregation dynamics without full knowledge of the underlying biological mechanisms. The fluorescent cell tracking revealed large deviations in the behavior of individual cells. Our modeling method indicated that decreased cell motility inside the aggregates, a biased walk toward aggregate centroids, and alignment among neighboring cells in a radial direction to the nearest aggregate are behaviors that enhance aggregation dynamics. Our modeling method also revealed that aggregation is generally robust to perturbations in these behaviors and identified possible compensatory mechanisms. The resulting approach of directly combining behavior quantification with data-driven simulations can be applied to more complex systems of collective cell movement without prior knowledge of the cellular machinery and behavioral cues.

Assessing the effects of subgrade frost heave on vehicle dynamic behaviors on high-speed railway

2019 ◽  
Vol 158 ◽  
pp. 95-105 ◽  
Author(s):  
Xiaopei Cai ◽  
Yanke Liang ◽  
Tao Xin ◽  
Chaozhi Ma ◽  
Haoyu Wang
Keyword(s):  
High Speed ◽  
Frost Heave ◽  
Vehicle Dynamic ◽  
High Speed Railway ◽  
Dynamic Behaviors

scholarly journals 3D Tissue elongation via ECM stiffness-cued junctional remodeling

2018 ◽  
Author(s):  
Dong-Yuan Chen ◽  
Justin Crest ◽  
Sebastian J. Streichan ◽  
David Bilder
Keyword(s):  
Basement Membrane ◽  
Cell Shape ◽  
Cell Dynamics ◽  
Src Tyrosine Kinase ◽  
Average Cell ◽  
Cellular Behavior ◽  
Cell Behaviors ◽  
Oriented Cell Division ◽  
Morphometric Analyses ◽  
Membrane Stiffness

ABSTRACTOrgans are sculpted by extracellular as well as cell-intrinsic forces, but how collective cell dynamics are orchestrated in response to microenvironmental cues is poorly understood. Here we apply advanced image analysis to reveal ECM-responsive cell behaviors that drive elongation of the Drosophila follicle, a model 3D system in which basement membrane stiffness instructs tissue morphogenesis. Through in toto morphometric analyses of WT and ‘round egg’ mutants, we find that neither changes in average cell shape nor oriented cell division are required for appropriate organ shape. Instead, a major element is a reorientation of elongated cells at the follicle anterior. Polarized reorientation is regulated by mechanical cues from the basement membrane, which are transduced by the Src tyrosine kinase to alter junctional E-cadherin trafficking. This mechanosensitive cellular behavior represents a conserved mechanism that can elongate ‘edgeless’ tubular epithelia in a process distinct from those that elongate bounded, planar epithelia.

Dynamic behaviors of coarse granular aggregates in high-speed railway subgrades

2022 ◽  
Vol 152 ◽  
pp. 107046
Author(s):  
Fei Zhang ◽  
Tianliang Wang ◽  
Jianqing Bu ◽  
Zhaoai Yin
Keyword(s):  
High Speed ◽  
High Speed Railway ◽  
Dynamic Behaviors

Dynamic behaviors of a high-speed turbocharger rotor on elliptical floating-ring bearings

2019 ◽  
Vol 233 (12) ◽  
pp. 1785-1799 ◽  
Author(s):  
Congcong Zhang ◽  
Yongliang Wang ◽  
Rixiu Men ◽  
Hong He ◽  
Wei Chen
Keyword(s):  
High Speed ◽  
Reynolds Equation ◽  
Low Cost ◽  
Dynamic Behaviors ◽  
Oil Whirl ◽  
Excited Vibration ◽  
Dynamic Performances ◽  
Simulation Results ◽  
Bearing Design ◽  
Run Up

Floating-ring bearings are commonly used in automotive turbocharger applications due to their low cost and their suitability under extreme rotation speeds. This type of bearings, however, can become a source of noise due to oil whirl-induced sub-synchronous vibrations. The scope of this paper is to examine whether the concept of a floating-ring bearing with an elliptical clearance might be a solution to suppress sub-synchronous vibrations. A very time-efficient approximate solution for the Reynolds equation to the geometry of elliptical bearings is presented. The nonlinear dynamic behaviors of a turbocharger rotor supported by two concepts of elliptical floating-ring bearings are systematically investigated using run-up simulations. For the first concept of elliptical floating-ring bearings i.e. the outer bearing of the floating-ring bearing changed in the form of elliptical pattern (see Figure 1(b) in the article), some studies have pointed out that its steady-state and dynamic performances are superior to plain cylindrical floating-ring bearings but, the nonlinear run-up simulation results shown that this type of elliptical floating-ring bearings is not conducive to reduce the self-excited vibration levels. However, for the second type of elliptical floating-ring bearings i.e. both the inner and outer films of the floating-ring bearing changed in the form of elliptical pattern (see Figure 1(c) in the article), it is shown that the sub-synchronous vibrations have been considerably suppressed. Hence, the second noncircular floating-ring bearing design is an attractive measure to suppress self-excited vibrations.[Figure: see text]

Dynamics Analysis and Vibration Isolation Design of Shared Foundation on Marine Turbo Generator Set

2013 ◽  
Vol 572 ◽  
pp. 193-196
Author(s):  
Chong Liu ◽  
Chang Hua Qiu ◽  
Lei Gao
Keyword(s):  
High Speed ◽  
Vibration Isolation ◽  
Stable Operation ◽  
Dynamical Response ◽  
Dynamics Analysis ◽  
Analysis Model ◽  
Lumped Mass ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Turbo Generator

Considering the ship's limited space, high speed and miniaturization have been design directions in marine turbo generator set. The shared foundation with steel plate welding is designed to support the marine turbo generator set. Stiffness and dynamic characteristic of the shared foundation will directly affect the stable operation of the turbo generator set. The paper established the dynamics analysis model for the shared frame of marine turbo generator set according to the 'Lumped Mass Method'. Taking account of the frequency-domain analysis operability, the operational modal analysis and dynamical response on foundation were carried out by Virtual Lab. Based on these results; the intensity and location of exciting force were ascertained. And then, we designed the shared foundation vibration isolation system, and analyzed the characteristics of the vibration isolation mounting. The result shows that the vibration isolation system can minimize output force transmissibility and reduce the effect of the marine turbo generator set vibration.

An integrated model for high-speed motorized spindles – Dynamic behaviors

2013 ◽  
Vol 227 (11) ◽  
pp. 2467-2478 ◽  
Author(s):  
Xiao-an Chen ◽  
Jun-feng Liu ◽  
Ye He ◽  
Peng Zhang ◽  
Wen-tao Shan
Keyword(s):  
Dynamic Model ◽  
Heat Generation ◽  
Thermal Model ◽  
High Speed ◽  
High Efficiency ◽  
Solution Procedure ◽  
Integrated Model ◽  
Dynamic Behaviors ◽  
Dynamic Performances ◽  
Motorized Spindles

With increasing popularity in high-speed machining due to its high efficiency, there is a vital need for more accurate prediction of dynamic behaviors for high-speed motorized spindles. The spindle units integrate tools with built-in motors hence a comprehensive model is required to include the multi-physics coupling property. This article presents an integrated model which consists of four coupled sub-models: state, shaft, bearing, and thermal model. Using the variational principle, a state model for the motor-spindle system is generated, which can describe the running state of the spindle, and provide electrical parameters to study the motor heat generation for thermal model and the unbalanced magnetic force for shaft dynamic model. The thermal model is coupled with the bearing and shaft dynamic model through bearing heat generation and thermal displacement. Thus, the entire model becomes an integrated electro-thermo-mechanical dynamic model. The proposed integrated model is investigated by a solution procedure and validated experimentally, and it shows that the model is capable of accurately predicting the dynamic behaviors of motorized spindles. The coupling relationship among the electrical, thermal, and mechanical behaviors of the system becomes clear from the simulation and experimental results, and some feasible methods to improve the dynamic performances of the system are obtained.

scholarly journals Cardiac function modulates endocardial cell dynamics to shape the cardiac outflow tract

2019 ◽  
Author(s):  
Pragya Sidhwani ◽  
Giulia L.M. Boezio ◽  
Hongbo Yang ◽  
Neil C. Chi ◽  
Beth L. Roman ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Outflow Tract ◽  
Cell Dynamics ◽  
Cell Behaviors ◽  
Cell Accumulation ◽  
Tgfβ Receptor ◽  
Heart Formation ◽  
Physical Forces ◽  
Endocardial Cell ◽  
Cardiac Outflow

ABSTRACTPhysical forces are important participants in the cellular dynamics that shape developing organs. During heart formation, for example, contractility and blood flow generate biomechanical cues that influence patterns of cell behavior. Here, we address the interplay between function and form during the assembly of the cardiac outflow tract (OFT), a crucial connection between the heart and vasculature that develops while circulation is underway. In zebrafish, we find that the OFT expands via accrual of both endocardial and myocardial cells. However, when cardiac function is disrupted, OFT endocardial growth ceases, accompanied by reduced proliferation and reduced addition of cells from adjacent vessels. The TGFβ receptor Acvrl1 is required for addition of endocardial cells, but not for their proliferation, indicating distinct regulation of these essential cell behaviors. Together, our results suggest that cardiac function modulates OFT morphogenesis by triggering endocardial cell accumulation that induces OFT lumen expansion and shapes OFT dimensions.

scholarly journals Transendothelial migration induces differential migration dynamics of leukocytes in tissue matrix

2021 ◽  
Author(s):  
Abraham C. I. van Steen ◽  
Lanette Kempers ◽  
Rouven Schoppmeyer ◽  
Max Blokker ◽  
David J. Beebe ◽  
...  
Keyword(s):  
T Cells ◽  
Real Time ◽  
High Speed ◽  
Cell Tracking ◽  
The Matrix ◽  
Migration Dynamics ◽  
Leukocyte Extravasation ◽  
Tissue Matrix ◽  
Actin Remodelling

Leukocyte extravasation into inflamed tissue is a complex process that is difficult to capture as a whole in vitro. We employed a blood-vessel-on-a-chip model in which endothelial cells were cultured in a tube-like lumen in a collagen-1 matrix. The vessels are leak-tight, creating a barrier for molecules and leukocytes. Addition of inflammatory cytokine TNF-α caused vasoconstriction, actin remodelling and upregulation of ICAM-1. Introducing leukocytes into the vessels allowed real-time visualisation of all different steps of the leukocyte transmigration cascade including migration into the extracellular matrix. Individual cell tracking over time distinguished striking differences in migratory behaviour between T-cells and neutrophils. Neutrophils cross the endothelial layer more efficiently than T-cells, but upon entering the matrix, neutrophils display high speed but low persistence, whereas T-cells migrate with low speed and rather linear migration. In conclusion, 3D imaging in real-time of leukocyte extravasation in a vessel-on-a-chip enables detailed qualitative and quantitative analysis of different stages of the full leukocyte extravasation process in a single assay.

Sign in / Sign up

Export Citation Format

Share Document