scholarly journals Matching material and cellular timescales maximizes cell spreading on viscoelastic substrates

2018 ◽  
Vol 115 (12) ◽  
pp. E2686-E2695 ◽  
Author(s):  
Ze Gong ◽  
Spencer E. Szczesny ◽  
Steven R. Caliari ◽  
Elisabeth E. Charrier ◽  
Ovijit Chaudhuri ◽  
...  
Keyword(s):  
Focal Adhesions ◽  
Cell Spreading ◽  
Optimal Level ◽  
Cellular Adhesion ◽  
Direct Monte Carlo Simulation ◽  
Material Parameters ◽  
Wide Range ◽  
Maximum Cell ◽  
And Function ◽  
Characteristic Binding

Recent evidence has shown that, in addition to rigidity, the viscous response of the extracellular matrix (ECM) significantly affects the behavior and function of cells. However, the mechanism behind such mechanosensitivity toward viscoelasticity remains unclear. In this study, we systematically examined the dynamics of motor clutches (i.e., focal adhesions) formed between the cell and a viscoelastic substrate using analytical methods and direct Monte Carlo simulation. Interestingly, we observe that, for low ECM rigidity, maximum cell spreading is achieved at an optimal level of viscosity in which the substrate relaxation time falls between the timescale for clutch binding and its characteristic binding lifetime. That is, viscosity serves to stiffen soft substrates on a timescale faster than the clutch off-rate, which enhances cell−ECM adhesion and cell spreading. On the other hand, for substrates that are stiff, our model predicts that viscosity will not influence cell spreading, since the bound clutches are saturated by the elevated stiffness. The model was tested and validated using experimental measurements on three different material systems and explained the different observed effects of viscosity on each substrate. By capturing the mechanism by which substrate viscoelasticity affects cell spreading across a wide range of material parameters, our analytical model provides a useful tool for designing biomaterials that optimize cellular adhesion and mechanosensing.

Chaperonin as the normal controls and pathological anti-stress response in the human reproductive system

2016 ◽  
pp. 126-129
Author(s):  
M. Makarenko ◽  
◽  
D. Hovsyeyev ◽  
L. Sydoryk ◽  
◽  
...  
Keyword(s):  
Reproductive System ◽  
Stress Proteins ◽  
Physiological Stress ◽  
Protein Complexes ◽  
Reproductive Function ◽  
Intercellular Signaling ◽  
Toll Like Receptors ◽  
Wide Range ◽  
Protein Functions ◽  
And Function

Different kinds of physiological stress cause mass changes in the cells, including the changes in the structure and function of the protein complexes and in separate molecules. The protein functions is determined by its folding (the spatial conclusion), which depends on the functioning of proteins of thermal shock- molecular chaperons (HSPs) or depends on the stress proteins, that are high-conservative; specialized proteins that are responsible for the correct proteinaceous folding. The family of the molecular chaperones/ chaperonins/ Hsp60 has a special place due to the its unique properties of activating the signaling cascades through the system of Toll-like receptors; it also stimulates the cells to produce anti- inflammatory cytokines, defensins, molecules of cell adhesion and the molecules of MHC; it functions as the intercellular signaling molecule. The pathological role of Hsp60 is established in a wide range of illnesses, from diabetes to atherosclerosis, where Hsp60 takes part in the regulation of both apoptosis and the autoimmune processes. The presence of the HSPs was found in different tissues that are related to the reproductive system. Key words: molecular chaperons (HSPs), Toll-like receptors, reproductive function, natural auto antibody.

Possession and Repetition

2012 ◽  
Vol 6 (1-3) ◽  
pp. 243-259 ◽  
Author(s):  
Yohan Yoo
Keyword(s):  
First Century ◽  
Daily Lives ◽  
Modern Times ◽  
Sacred Texts ◽  
New Methods ◽  
Wide Range ◽  
Lay Buddhists ◽  
Iconic Status ◽  
And Function ◽  
To Receive

This article demonstrates the need for the iconic status and function of Buddhist scripture to receive more attention by illuminating how lay Korean Buddhists try to appropriate the power of sutras. The oral and aural aspects of scripture, explained by Wilfred Cantwell Smith, provide only a limited understanding of the characteristics of scripture. It should be noted that, before modern times, most lay people, not only in Buddhist cultures but also in Christian and other traditions, neither had the chance to recite scriptures nor to listen to their recitations regularly. Several clear examples demonstrate contemporary Korean Buddhists’ acceptance of the iconic status of sutras and their attempt to appropriate the power and status of those sacred texts. In contemporary Korea, lay Buddhists try to claim the power of scriptures in their daily lives by repeating and possessing them. Twenty-first century lay believers who cannot read or recite in a traditional style have found new methods of repetition, such as internet programs for copying sacred texts and for playing recordings of their recitations. In addition, many Korean Buddhists consider the act of having sutras in one’s possession to be an effective way of accessing the sacred status and power of these texts. Hence, various ways of possessing them have been developed in a wide range of products, from fancy gilded sutras to sneakers embroidered with mantras.

The Art of Love Poetry

2018 ◽  
Author(s):  
Erik Gray
Keyword(s):  
Popular Culture ◽  
Cultural History ◽  
Literary Tradition ◽  
Love Poetry ◽  
Erotic Love ◽  
Wide Range ◽  
History Of ◽  
And Function ◽  
Meaning And Function ◽  
Comprehensive History

Love begets poetry; poetry begets love. These two propositions have seemed evident to thinkers and poets across the Western literary tradition. Plato writes that “anyone that love touches instantly becomes a poet.” And even today, when poetry has largely disappeared from the mainstream of popular culture, it retains its romantic associations. But why should this be so—what are the connections between poetry and erotic love that lead us to associate them so strongly with one another? An examination of different theories of both love and poetry across the centuries reveals that the connection between them is not merely an accident of cultural history—the result of our having grown up hearing, or hearing about, love poetry—but something more intrinsic. Even as definitions of them have changed, the two phenomena have consistently been described in parallel terms. Love is characterized by paradox. Above all, it is both necessarily public, because interpersonal, and intensely private; hence it both requires expression and resists it. In poetry, especially lyric poetry, which features its own characteristic paradoxes and silences, love finds a natural outlet. This study considers both the theories and the love poems themselves, bringing together a wide range of examples from different eras in order to examine the major structures that love and poetry share. It does not aim to be a comprehensive history of Western love poetry, but an investigation into the meaning and function of recurrent tropes, forms, and images employed by poets to express and describe erotic love.

scholarly journals TOWARDS FUNCTIONAL ARCHITECTURAL DECOMPOSITION OF CONSTRAINED LAYER INFLATABLE SYSTEMS

2021 ◽  
Vol 1 ◽  
pp. 3219-3228
Author(s):  
Koray Benli ◽  
Jonathan Luntz ◽  
Diann Brei ◽  
Wonhee Kim ◽  
Paul Alexander ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Form And Function ◽  
New Concepts ◽  
Wide Range ◽  
Systematic Understanding ◽  
And Function

AbstractPneumatically activated systems enable myriad types of highly functional inflatables employing a wide range of architectural approaches affecting their form and function, making systematic conceptual design difficult. A new architectural class of pneumatically activated systems, constrained layer inflatable systems, consists of hierarchically architected flat layers of thin airtight bladders that are internally and/or externally constrained to generate a variety of functionalities. The highly hierarchical architectural structure of constrained layer inflatable systems coincides with the hierarchy of produced functions, providing an opportunity for the development of a functional architectural decomposition, capturing the inherent relationship between architectural and functional hierarchies. The basis of the approach is conveyed through the design of an example constrained layer inflatable system. This approach empowers the systematic understanding of the interrelated architectural and functional breakdown of constrained layer inflatable systems, enabling designers to iteratively analyze, synthesize, and re-synthesize the components of the system improving existing designs and exploring new concepts.

scholarly journals Raman Spectroscopy Investigation of Graphene Oxide Reduction by Laser Scribing

2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Vittorio Scardaci ◽  
Giuseppe Compagnini
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Reduce Graphene Oxide ◽  
Oxide Reduction ◽  
Material Parameters ◽  
Laser Scribing ◽  
Wide Range ◽  
Scan Speed ◽  
Laser Reduction

Laser scribing has been proposed as a fast and easy tool to reduce graphene oxide (GO) for a wide range of applications. Here, we investigate laser reduction of GO under a range of processing and material parameters, such as laser scan speed, number of laser passes, and material coverage. We use Raman spectroscopy for the characterization of the obtained materials. We demonstrate that laser scan speed is the most influential parameter, as a slower scan speed yields poor GO reduction. The number of laser passes is influential where the material coverage is higher, producing a significant improvement of GO reduction on a second pass. Material coverage is the least influential parameter, as it affects GO reduction only under restricted conditions.

Calibration of Mobility and Interface Trap Parameters for High Temperature TCAD Simulation of 4H-SiC VDMOSFETs

2012 ◽  
Vol 717-720 ◽  
pp. 1101-1104 ◽  
Author(s):  
M.G. Jaikumar ◽  
Shreepad Karmalkar
Keyword(s):  
Surface Roughness ◽  
Measured Data ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Material Parameters ◽  
Velocity Saturation ◽  
Physical Mechanisms ◽  
Surface Roughness Scattering ◽  
Wide Range ◽  
Tcad Simulation

4H-Silicon Carbide VDMOSFET is simulated using the Sentaurus TCAD package of Synopsys. The simulator is calibrated against measured data for a wide range of bias conditions and temperature. Material parameters of 4H-SiC are taken from literature and used in the available silicon models of the simulator. The empirical parameters are adjusted to get a good fit between the simulated curves and measured data. The simulation incorporates the bias and temperature dependence of important physical mechanisms like interface trap density, coulombic interface trap scattering, surface roughness scattering and velocity saturation.

Myocilin binding to Hep II domain of fibronectin inhibits cell spreading and incorporation of paxillin into focal adhesions

2005 ◽  
Vol 303 (2) ◽  
pp. 218-228 ◽  
Author(s):  
Donna M. Peters ◽  
Kathleen Herbert ◽  
Brenda Biddick ◽  
Jennifer A. Peterson
Keyword(s):  
Focal Adhesions ◽  
Cell Spreading

TETRASPORE is required for male meiotic cytokinesis in Arabidopsis thaliana

Development ◽  
1997 ◽  
Vol 124 (13) ◽  
pp. 2645-2657 ◽  
Author(s):  
M. Spielman ◽  
D. Preuss ◽  
F.L. Li ◽  
W.E. Browne ◽  
R.J. Scott ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Development ◽  
Male Meiosis ◽  
Pollen Grain ◽  
Flowering Plants ◽  
External Wall ◽  
Normal Pollen ◽  
Wide Range ◽  
Asymmetric Divisions ◽  
And Function

In flowering plants, male meiosis occurs in the microsporocyte to produce four microspores, each of which develops into a pollen grain. Here we describe four mutant alleles of TETRASPORE (TES), a gene essential for microsporocyte cytokinesis in Arabidopsis thaliana. Following failure of male meiotic cytokinesis in tes mutants, all four microspore nuclei remain within the same cytoplasm, with some completing their developmental programmes to form functional pollen nuclei. Both of the mitotic divisions seen in normal pollen development take place in tes mutants, including the asymmetric division required for the differentiation of gametes; some tes grains perform multiple asymmetric divisions in the same cytoplasm. tes pollen shows a variety of abnormalities subsequent to the cytokinetic defect, including fusion of nuclei, formation of ectopic internal walls, and disruptions to external wall patterning. In addition, ovules fertilized by tes pollen often abort, possibly because of excess paternal genomes in the endosperm. Thus tes mutants not only reveal a gene specific to male meiosis, but aid investigation of a wide range of processes in pollen development and function.

Syndesmos, a protein that interacts with the cytoplasmic domain of syndecan-4, mediates cell spreading and actin cytoskeletal organization

2000 ◽  
Vol 113 (2) ◽  
pp. 315-324 ◽  
Author(s):  
P.C. Baciu ◽  
S. Saoncella ◽  
S.H. Lee ◽  
F. Denhez ◽  
D. Leuthardt ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Cytoplasmic Domain ◽  
Cellular Protein ◽  
Actin Stress Fiber ◽  
Independent Manner ◽  
Intracellular Proteins ◽  
Central Regions ◽  
A Cell

Syndecan-4 is a cell surface heparan sulfate proteoglycan which, in cooperation with integrins, transduces signals for the assembly of focal adhesions and actin stress fibers in cells plated on fibronectin. The regulation of these cellular events is proposed to occur, in part, through the interaction of the cytoplasmic domains of these transmembrane receptors with intracellular proteins. To identify potential intracellular proteins that interact with the cytoplasmic domain of syndecan-4, we carried out a yeast two-hybrid screen in which the cytoplasmic domain of syndecan-4 was used as bait. As a result of this screen, we have identified a novel cellular protein that interacts with the cytoplasmic domain of syndecan-4 but not with those of the other three syndecan family members. The interaction involves both the membrane proximal and variable central regions of the cytoplasmic domain. We have named this cDNA and encoded protein syndesmos. Syndesmos is ubiquitously expressed and can be myristylated. Consistent with its myristylation and syndecan-4 association, syndesmos colocalizes with syndecan-4 in the ventral plasma membranes of cells plated on fibronectin. When overexpressed in NIH 3T3 cells, syndesmos enhances cell spreading, actin stress fiber and focal contact formation in a serum-independent manner.

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