scholarly journals Effect of loading conditions on the dissociation behaviour of catch bond clusters

2011 ◽  
Vol 9 (70) ◽  
pp. 928-937 ◽  
Author(s):  
L. Sun ◽  
Q. H. Cheng ◽  
H. J. Gao ◽  
Y. W. Zhang
Keyword(s):  
Multiple Bond ◽  
Tensile Load ◽  
Load Sharing ◽  
Loading Conditions ◽  
Bond Behaviour ◽  
Catch Bond ◽  
Linear Load ◽  
Bond System ◽  
Bond Mechanism ◽  
Catch Bonds

Under increasing tensile load, the lifetime of a single catch bond counterintuitively increases up to a maximum and then decreases exponentially like a slip bond. So far, the characteristics of single catch bond dissociation have been extensively studied. However, it remains unclear how a cluster of catch bonds behaves under tensile load. We perform computational analysis on the following models to examine the characteristics of clustered catch bonds: (i) clusters of catch bonds with equal load sharing, (ii) clusters of catch bonds with linear load sharing, and (iii) clusters of catch bonds in micropipette-manipulated cell detachment. We focus on the differences between the slip and catch bond clusters, identifying the critical factors for exhibiting the characteristics of catch bond mechanism for the multiple-bond system. Our computation reveals that for a multiple-bond cluster, the catch bond behaviour could only manifest itself under relatively uniform loading conditions and at certain stages of decohesion, explaining the difficulties in observing the catch bond mechanism under real biological conditions.

scholarly journals High force catch bond mechanism of bacterial adhesion in the human gut

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhaowei Liu ◽  
Haipei Liu ◽  
Andrés M. Vera ◽  
Rafael C. Bernardi ◽  
Philip Tinnefeld ◽  
...  
Keyword(s):  
Bacterial Adhesion ◽  
Human Gut ◽  
Catch Bond ◽  
Bond Mechanism

Asymptotic bounds on the time to fatigue failure of bundles of fibers under local load sharing

1982 ◽  
Vol 14 (01) ◽  
pp. 95-121 ◽  
Author(s):  
Luke Tierney
Keyword(s):  
Fatigue Failure ◽  
General Framework ◽  
Applied Load ◽  
Tensile Load ◽  
Load Sharing ◽  
Local Load ◽  
Fiber Bundles ◽  
Asymptotic Bounds ◽  
Parallel Arrangement ◽  
A Chain

A fiber bundle is a parallel arrangement of fibers. Under a steady tensile load, fibers fail randomly in time in a manner that depends on how they share the applied load. The bundle fails when all its fibers have failed in a specified region.In this paper we consider the fatigue failure of such a bundle in a fiber load-sharing setting appropriate for composite materials, that is, to bundles impregnated with a flexible matrix. The bundle is actually modelled as a chain of short bundles, and local load sharing is assumed for the fibers within each short bundle. The chain of bundles fails once all the fibers in one of the short bundles have failed.Reasonable assumptions are made on the stochastic failure of individual fibers. A general framework for describing fiber bundles is developed and is used to derive the limiting distribution of the time to the first appearance of a set ofkor more adjacent failed fibers as the number of fibers in the bundle grows large. These results provide useful bounds on the distribution of the time to total bundle failure. Some implications and extensions of these results are discussed.

The Load Sharing Contribution of Spinal Facet Joint During Impact Loading: A Porcine Biomechanical Model

2003 ◽  
Author(s):  
Cheng-Chuan Lai ◽  
Jaw-Lin Wang ◽  
Guan-Liang Chang ◽  
Cheng-Hsien Chung
Keyword(s):  
Impact Energy ◽  
Impact Loading ◽  
Facet Joint ◽  
Biomechanical Model ◽  
Load Sharing ◽  
Loading Conditions ◽  
Vertical Loading ◽  
Motion Segment ◽  
The Impact

The components that share the loading of motion segment include the facet joint and disc. Nachemson [1] reported the facet joint share 18% of vertical loading in a motion segment; while many other researchers reported the load sharing percentage of facet joint ranges from 1% to 57% [2,3]. The current study developed a unique apparatus using an in vitro porcine spine model to quantify the alteration of loading in the facet joint under impact compressive loading at different loading conditions. A drop tower type impact apparatus was used to produce the impact energy for the motion segment. A 6-D load cell was placed under the specimen to detect the force and moment responses. The pressure sensor was inserted into the facet joint to find the contact force. The pointed axial compresive forces were applied at 8 locations from anterior to posterior of upper vertebrae to mimic different impact loading conditions. The impact energy was fixed at 1.2 J. We found that; when the loading was applied anteriorly, the facet joint sustained very small percentages of the loading; while the location of the loading moved posteriorly, the facet joint sharing percentages increased. The largest sharing percentages of facet joint reached 30% in the current study.

scholarly journals Catch-Bond Mechanism of Force-Enhanced Adhesion: Counterintuitive, Elusive, but … Widespread?

2008 ◽  
Vol 4 (4) ◽  
pp. 314-323 ◽  
Author(s):  
Evgeni V. Sokurenko ◽  
Viola Vogel ◽  
Wendy E. Thomas
Keyword(s):  
Catch Bond ◽  
Bond Mechanism

scholarly journals Catch-bond behaviour facilitates membrane tubulation by non-processive myosin 1b

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Ayako Yamada ◽  
Alexandre Mamane ◽  
Jonathan Lee-Tin-Wah ◽  
Aurélie Di Cicco ◽  
Coline Prévost ◽  
...  
Keyword(s):  
Bond Behaviour ◽  
Catch Bond ◽  
Membrane Tubulation

Effects of Tooth Indexing Errors on Load Distribution and Tooth Load Sharing of Splines Under Combined Loading Conditions

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
J. Hong ◽  
D. Talbot ◽  
A. Kahraman
Keyword(s):  
Load Distribution ◽  
Probability Distributions ◽  
Random Sequence ◽  
Load Sharing ◽  
Spur Gear ◽  
Combined Loading ◽  
Distribution Model ◽  
Loading Conditions ◽  
Manufacturing Tolerance ◽  
Single Tooth

In this paper, influences of tooth indexing errors on load distribution and tooth load sharing of spline joints are investigated by modifying an existing semi-analytical load distribution model for side-fit involute splines. Two commonly observed loading conditions, namely (i) combined torsion and radial loads representative of a spline joint of a spur gear with shaft and (ii) combined torsion, radial loads, and tilting moment representative of a spline joint of a helical gear with shaft are considered in this study. Numerical results of an example spline having (i) no tooth indexing error, (ii) a single tooth with indexing error, and (iii) a random sequence of tooth indexing errors under these two loading conditions are presented to demonstrate the effects of tooth indexing errors. In addition, a practical study of the robustness to manufacturing tolerances is also presented where probability distributions of load sharing factor of the critical tooth of an example spline designed to certain manufacturing tolerance classes are obtained with a large number of randomly generated indexing error sequences.

scholarly journals Demonstration of catch bonds between an integrin and its ligand

2009 ◽  
Vol 185 (7) ◽  
pp. 1275-1284 ◽  
Author(s):  
Fang Kong ◽  
Andrés J. García ◽  
A. Paul Mould ◽  
Martin J. Humphries ◽  
Cheng Zhu
Keyword(s):  
Active Conformation ◽  
Integrin Α5β1 ◽  
Catch Bond ◽  
Force Microscopy ◽  
Atomic Force ◽  
Force Range ◽  
Integrin Ligand ◽  
Single Bonds ◽  
Catch Bonds ◽  
Bond Region

Binding of integrins to ligands provides anchorage and signals for the cell, making them prime candidates for mechanosensing molecules. How force regulates integrin–ligand dissociation is unclear. We used atomic force microscopy to measure the force-dependent lifetimes of single bonds between a fibronectin fragment and an integrin α5β1-Fc fusion protein or membrane α5β1. Force prolonged bond lifetimes in the 10–30-pN range, a counterintuitive behavior called catch bonds. Changing cations from Ca2+/Mg2+ to Mg2+/EGTA and to Mn2+ caused longer lifetime in the same 10–30-pN catch bond region. A truncated α5β1 construct containing the headpiece but not the legs formed longer-lived catch bonds that were not affected by cation changes at forces <30 pN. Binding of monoclonal antibodies that induce the active conformation of the integrin headpiece shifted catch bonds to a lower force range. Thus, catch bond formation appears to involve force-assisted activation of the headpiece but not integrin extension.

scholarly journals Plasma fibronectin stabilizes Borrelia burgdorferi–endothelial interactions under vascular shear stress by a catch-bond mechanism

2017 ◽  
Vol 114 (17) ◽  
pp. E3490-E3498 ◽  
Author(s):  
Alexandra F. Niddam ◽  
Rhodaba Ebady ◽  
Anil Bansal ◽  
Anne Koehler ◽  
Boris Hinz ◽  
...  
Keyword(s):  
Shear Stress ◽  
Borrelia Burgdorferi ◽  
Live Cell Imaging ◽  
Host Cells ◽  
Catch Bond ◽  
Bacterial Dissemination ◽  
Bacterial Interaction ◽  
Blood Constituent ◽  
Formed Part ◽  
Bond Mechanism

Bacterial dissemination via the cardiovascular system is the most common cause of infection mortality. A key step in dissemination is bacterial interaction with endothelia lining blood vessels, which is physically challenging because of the shear stress generated by blood flow. Association of host cells such as leukocytes and platelets with endothelia under vascular shear stress requires mechanically specialized interaction mechanisms, including force-strengthened catch bonds. However, the biomechanical mechanisms supporting vascular interactions of most bacterial pathogens are undefined. Fibronectin (Fn), a ubiquitous host molecule targeted by many pathogens, promotes vascular interactions of the Lyme disease spirochete Borrelia burgdorferi. Here, we investigated how B. burgdorferi exploits Fn to interact with endothelia under physiological shear stress, using recently developed live cell imaging and particle-tracking methods for studying bacterial–endothelial interaction biomechanics. We found that B. burgdorferi does not primarily target insoluble matrix Fn deposited on endothelial surfaces but, instead, recruits and induces polymerization of soluble plasma Fn (pFn), an abundant protein in blood plasma that is normally soluble and nonadhesive. Under physiological shear stress, caps of polymerized pFn at bacterial poles formed part of mechanically loaded adhesion complexes, and pFn strengthened and stabilized interactions by a catch-bond mechanism. These results show that B. burgdorferi can transform a ubiquitous but normally nonadhesive blood constituent to increase the efficiency, strength, and stability of bacterial interactions with vascular surfaces. Similar mechanisms may promote dissemination of other Fn-binding pathogens.

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