scholarly journals The adhesion force of Notch with Delta and the rate of Notch signaling

2004 ◽  
Vol 167 (6) ◽  
pp. 1217-1229 ◽  
Author(s):  
Francois Ahimou ◽  
Lee-Peng Mok ◽  
Boris Bardot ◽  
Cedric Wesley
Keyword(s):  
Notch Signaling ◽  
Adhesion Force ◽  
High Rate ◽  
Live Cells ◽  
Cell Fates ◽  
Animal Development ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Adhesion ◽  
Strong Adhesion

Notch signaling is repeatedly used during animal development to specify cell fates. Using atomic force microscopy on live cells, chemical inhibitors, and conventional analyses, we show that the rate of Notch signaling is linked to the adhesion force between cells expressing Notch receptors and Delta ligand. Both the Notch extracellular and intracellular domains are required for the high adhesion force with Delta. This high adhesion force is lost within minutes, primarily due to the action of Presenilin on Notch. Reduced turnover or Delta pulling accelerate this loss. These data suggest that strong adhesion between Notch and Delta might serve as a booster for initiating Notch signaling at a high rate.

scholarly journals Assessing the Functional Properties of TiZr Nanotubular Structures for Biomedical Applications, through Nano-Scratch Tests and Adhesion Force Maps

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 900
Author(s):  
Maria Vardaki ◽  
Aida Pantazi ◽  
Ioana Demetrescu ◽  
Marius Enachescu
Keyword(s):  
Surface Roughness ◽  
Functional Properties ◽  
Bacterial Adhesion ◽  
Biomedical Applications ◽  
Adhesion Force ◽  
Roughness Parameters ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Mean ◽  
Scratch Tests

In this work we present the results of a functional properties assessment via Atomic Force Microscopy (AFM)-based surface morphology, surface roughness, nano-scratch tests and adhesion force maps of TiZr-based nanotubular structures. The nanostructures have been electrochemically prepared in a glycerin + 15 vol.% H2O + 0.2 M NH4F electrolyte. The AFM topography images confirmed the successful preparation of the nanotubular coatings. The Root Mean Square (RMS) and average (Ra) roughness parameters increased after anodizing, while the mean adhesion force value decreased. The prepared nanocoatings exhibited a smaller mean scratch hardness value compared to the un-coated TiZr. However, the mean hardness (H) values of the coatings highlight their potential in having reliable mechanical resistances, which along with the significant increase of the surface roughness parameters, which could help in improving the osseointegration, and also with the important decrease of the mean adhesion force, which could lead to a reduction in bacterial adhesion, are providing the nanostructures with a great potential to be used as a better alternative for Ti implants in dentistry.

scholarly journals An Atomic Force Microscopy Study of Live Cells and Biofilms of Rhizobium Leguminosarum

2011 ◽  
Vol 100 (3) ◽  
pp. 162a
Author(s):  
Jun Dong ◽  
Elizabeth M. Vanderlinde ◽  
Christopher K. Yost ◽  
Tanya E.S. Dahms
Keyword(s):  
Atomic Force Microscopy ◽  
Rhizobium Leguminosarum ◽  
Microscopy Study ◽  
Live Cells ◽  
Atomic Force Microscopy Study ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Carbohydrate–carbohydrate interaction provides adhesion force and specificity for cellular recognition

2004 ◽  
Vol 165 (4) ◽  
pp. 529-537 ◽  
Author(s):  
Iwona Bucior ◽  
Simon Scheuring ◽  
Andreas Engel ◽  
Max M. Burger
Keyword(s):  
Adhesion Force ◽  
Species Specificity ◽  
Live Cells ◽  
Sponge Cell ◽  
Cell Recognition ◽  
Adhesion Forces ◽  
Cellular Recognition ◽  
Strong Adhesion ◽  
Species Specific ◽  
Cell Cell

The adhesion force and specificity in the first experimental evidence for cell–cell recognition in the animal kingdom were assigned to marine sponge cell surface proteoglycans. However, the question whether the specificity resided in a protein or carbohydrate moiety could not yet be resolved. Here, the strength and species specificity of cell–cell recognition could be assigned to a direct carbohydrate–carbohydrate interaction. Atomic force microscopy measurements revealed equally strong adhesion forces between glycan molecules (190–310 piconewtons) as between proteins in antibody–antigen interactions (244 piconewtons). Quantitative measurements of adhesion forces between glycans from identical species versus glycans from different species confirmed the species specificity of the interaction. Glycan-coated beads aggregated according to their species of origin, i.e., the same way as live sponge cells did. Live cells also demonstrated species selective binding to glycans coated on surfaces. These findings confirm for the first time the existence of relatively strong and species-specific recognition between surface glycans, a process that may have significant implications in cellular recognition.

Characterization of English ivy (Hedera helix) adhesion force and imaging using atomic force microscopy

2010 ◽  
Vol 13 (3) ◽  
pp. 1029-1037 ◽  
Author(s):  
Lijin Xia ◽  
Scott C. Lenaghan ◽  
Mingjun Zhang ◽  
Yu Wu ◽  
Xiaopeng Zhao ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Adhesion Force ◽  
Hedera Helix ◽  
Force Microscopy ◽  
Atomic Force ◽  
English Ivy

Surface diagnostics for scale analysis

2004 ◽  
Vol 49 (2) ◽  
pp. 183-190 ◽  
Author(s):  
S. Dunn ◽  
S. Impey ◽  
C. Kimpton ◽  
S.A. Parsons ◽  
J. Doyle ◽  
...  
Keyword(s):  
Adhesion Force ◽  
Polymer Materials ◽  
Rapid Screening ◽  
Force Measurements ◽  
Energy Materials ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Modified ◽  
Surface Diagnostics ◽  
Microscopy Techniques

Stainless steel, polymethylmethacrylate and polytetrafluoroethylene coupons were analysed for surface topographical and adhesion force characteristics using tapping mode atomic force microscopy and force-distance microscopy techniques. The two polymer materials were surface modified by polishing with silicon carbide papers of known grade. The struvite scaling rate was determined for each coupon and related to the data gained from the surface analysis. The scaling rate correlated well with adhesion force measurements indicating that lower energy materials scale at a lower rate. The techniques outlined in the paper provide a method for the rapid screening of materials in potential scaling applications.

scholarly journals Adhesion force mapping on wood by atomic force microscopy: influence of surface roughness and tip geometry

2016 ◽  
Vol 3 (10) ◽  
pp. 160248 ◽  
Author(s):  
X. Jin ◽  
B. Kasal
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Wood Surface ◽  
Adhesion Force ◽  
Data Interpretation ◽  
Natural Fibre ◽  
Force Distribution ◽  
Adhesion Forces ◽  
Force Microscopy ◽  
Atomic Force

This study attempts to address the interpretation of atomic force microscopy (AFM) adhesion force measurements conducted on the heterogeneous rough surface of wood and natural fibre materials. The influences of wood surface roughness, tip geometry and wear on the adhesion force distribution are examined by cyclic measurements conducted on wood surface under dry inert conditions. It was found that both the variation of tip and surface roughness of wood can widen the distribution of adhesion forces, which are essential for data interpretation. When a common Si AFM tip with nanometre size is used, the influence of tip wear can be significant. Therefore, control experiments should take the sequence of measurements into consideration, e.g. repeated experiments with used tip. In comparison, colloidal tips provide highly reproducible results. Similar average values but different distributions are shown for the adhesion measured on two major components of wood surface (cell wall and lumen). Evidence supports the hypothesis that the difference of the adhesion force distribution on these two locations was mainly induced by their surface roughness.

Resonance compensating chirp mode for mapping the rheology of live cells by high-speed atomic force microscopy

2018 ◽  
Vol 113 (9) ◽  
pp. 093701 ◽  
Author(s):  
Marc Schächtele ◽  
Erik Hänel ◽  
Tilman E. Schäffer
Keyword(s):  
Atomic Force Microscopy ◽  
High Speed ◽  
Live Cells ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Molecular Recognition and Cell Surface Biochemical Response of Bacillus thuringiensis on Triphenyltin

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 358
Author(s):  
Hongling Zhang ◽  
Jinshao Ye ◽  
Huaming Qin ◽  
Xujun Liang ◽  
Yan Long
Keyword(s):  
Bacillus Thuringiensis ◽  
Molecular Recognition ◽  
Cell Surface ◽  
Adhesion Force ◽  
Tween 80 ◽  
Cell Permeability ◽  
Surface Adhesion ◽  
Force Microscopy ◽  
Growth Status ◽  
Atomic Force

Triphenyltin (TPT) has severely polluted the environment, and it often coexists with metal ions, such as Cu2+. This paper describes the cell’s molecular recognition of TPT, the interaction between TPT recognition and Cu2+ biosorption, and their effect on cell permeability. We studied the recognition of TPT by Bacillus thuringiensis cells and the effect of TPT recognition on Cu2+ biosorption by using atomic force microscopy to observe changes in cell surface mechanical properties and cellular morphology and by using flow cytometry to determine the cell growth status and cell permeability. The results show that B. thuringiensis can quickly recognize different media. The adhesion force of cells in contact with Tween 80 was significantly reduced to levels that were much lower than that of cells in contact with PBS. Conversely, the cell surface adhesion force increased as TPT became more degraded. B. thuringiensis cells maintained their original morphology after 48 h of TPT treatment. The amount of Cu2+ adsorption by TPT-treated cells was positively correlated with the surface adhesion force (r = 0.966, P = 0.01). The cell adhesion force significantly decreased after Cu2+ adsorption, and cell recognition of TPT and/or Cu2+ hindered the entrance of 2’,7’-dichlorodihydrofluorescein diacetate (DCFH-DA) into the cell. The initial diffusion time of DCFH-DA into cells treated by PBS, Cu2+, TPT, and TPT+Cu2+ was 4, 10, 30, and 30 min, respectively, and the order of the fluorescence intensity was PBS >> Cu2+ > TPT > TPT+Cu2+. We conclude that changes in the cell surface properties of the microbe during recognition of pollutants depend on the contaminant’s properties. B. thuringiensis recognized TPT and secreted intracellular substances that not only enhanced the adsorption of Cu2+, but also formed a “barrier” on the cell surface that reduced permeability. These findings provide a novel insight into the mechanism of microbial removal of pollutants.

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