Fibre ropes - Electrostatic surface potential measuring method

2019 ◽  
Keyword(s):  
Surface Potential ◽  
Measuring Method ◽  
Electrostatic Surface Potential

scholarly journals Crystal structure of chloroplastic thioredoxin z defines a novel type-specific target recognition

2020 ◽  
Author(s):  
Théo Le Moigne ◽  
Libero Gurrieri ◽  
Pierre Crozet ◽  
Christophe H. Marchand ◽  
Mirko Zaffagnini ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Subcellular Localization ◽  
Surface Potential ◽  
Target Recognition ◽  
Chemical Mechanism ◽  
Protein Targets ◽  
Cycle Enzyme ◽  
Electrostatic Surface Potential ◽  
Trx Fold ◽  
Plant Sources

AbstractThioredoxins (TRXs) are ubiquitous disulfide oxidoreductases structured according to a highly conserved fold. TRXs are involved in a myriad of different processes through a common chemical mechanism. Plant thioredoxins evolved into seven types with diverse subcellular localization and distinct protein targets selectivity. Five TRX types coexist in the chloroplast, with yet scarcely described specificities. We solved the first crystal structure of a chloroplastic z-type TRX, revealing a conserved TRX fold with an original electrostatic surface potential surrounding the redox site. This recognition surface is distinct from all other known TRX types from plant and non-plant sources and is exclusively conserved in plant z-type TRXs. We show that this electronegative surface endows TRXz with a capacity to activate the photosynthetic Calvin-Benson cycle enzyme phosphoribulokinase. TRXz distinct electronegative surface thereby extends the repertoire of TRX-target recognitions.

scholarly journals Impact of Ciprofloxacin and Chloramphenicol on the Lipid Bilayer ofStaphylococcus aureus: Changes in Membrane Potential

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Paulina L. Páez ◽  
María C. Becerra ◽  
Inés Albesa
Keyword(s):  
Staphylococcus Aureus ◽  
Membrane Potential ◽  
Cell Membrane ◽  
Surface Potential ◽  
Binding Sites ◽  
Ofstaphylococcus Aureus ◽  
Bacterial Membranes ◽  
Electrostatic Surface Potential ◽  
Number Of Binding Sites ◽  
Resistant Strains

The present study was undertaken to explore the interaction of ciprofloxacin and chloramphenicol with bacterial membranes in a sensitive and in a resistant strains ofStaphylococcus aureusby using 1-anilino-8-naphthalene sulfonate (ANS). The binding of this probe to the cell membrane depends on the surface potential, which modulates the binding constant to the membrane. We observed that these antibiotics interacted with the bilayer, thus affecting the electrostatic surface potential. Alterations caused by antibiotics on the surface of the bacteria were accompanied by a reduction in the number of binding sites and an increase in the ANS dissociation constant in the sensitive strain, whereas in the ciprofloxacin-resistant strain no significant changes were detected. The changes seen in the electrostatic surface potential generated in the membrane ofS. aureusby the antibiotics provide new aspects concerning their action on the bacterial cell.

STABILITY OF ADSORBED HYDROGEN ON Si(100) UNDER CHANGES OF THE SURFACE POTENTIAL

1996 ◽  
Vol 03 (02) ◽  
pp. 1227-1233 ◽  
Author(s):  
P. KRATZER ◽  
B. HAMMER ◽  
F. GREY ◽  
J. K. NØRSKOV
Keyword(s):  
Charge Transfer ◽  
Simple Model ◽  
Ab Initio Calculations ◽  
Surface Potential ◽  
Space Charge Region ◽  
Adsorbed Hydrogen ◽  
Clean Surface ◽  
Important Ingredient ◽  
Electrostatic Surface Potential ◽  
Chemisorption Energy

We study the effect of an electrostatic surface potential on the chemisorption energy of H 2 on a Si (100)2×1 surface on the basis of a set of ab initio calculations. We find a sizeable destabilization of the adsorbate, because the clean surface gains in stability compared to the H-terminated surface due to charge transfer between dangling bonds and the space charge region below the surface. We rationalize our results in terms of a simple model and discuss the possibility that potential-induced destabilization is an important ingredient in understanding STM-induced nanolithography.

Quasi-one-dimensional cyano-phenylene aggregates: Uniform molecule alignment contrasts varying electrostatic surface potential

2017 ◽  
Vol 146 (13) ◽  
pp. 134704 ◽  
Author(s):  
Frank Balzer ◽  
Roland Resel ◽  
Arne Lützen ◽  
Manuela Schiek
Keyword(s):  
Surface Potential ◽  
One Dimensional ◽  
Electrostatic Surface Potential

Electrostatic surface potential and critical micelle concentration relationship for ionic micelles

Langmuir ◽  
1990 ◽  
Vol 6 (2) ◽  
pp. 506-508 ◽  
Author(s):  
Thomas W. Healy ◽  
Calum J. Drummond ◽  
Franz Grieser ◽  
Brent S. Murray
Keyword(s):  
Critical Micelle Concentration ◽  
Surface Potential ◽  
Electrostatic Surface Potential ◽  
Ionic Micelles

Effects of lactose permease of Escherichia coli on the anisotropy and electrostatic surface potential of liposomes

2006 ◽  
Vol 119 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Sandra Merino-Montero ◽  
M. Teresa Montero ◽  
Jordi Hernández-Borrell
Keyword(s):  
Escherichia Coli ◽  
Surface Potential ◽  
Lactose Permease ◽  
Electrostatic Surface Potential

scholarly journals Can Combined Electrostatic and Polarization Effects Alone Explain the F···F Negative-Negative Bonding in Simple Fluoro-Substituted Benzene Derivatives? A First-Principles Perspective

Computation ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 51 ◽  
Author(s):  
Pradeep Varadwaj ◽  
Arpita Varadwaj ◽  
Helder Marques ◽  
Koichi Yamashita
Keyword(s):  
Perturbation Theory ◽  
Charge Density ◽  
Surface Potential ◽  
First Principles ◽  
Crystal Packing ◽  
Bond Critical Point ◽  
Equilibrium Geometry ◽  
Type I ◽  
Electrostatic Surface Potential ◽  
Intermolecular Distances

The divergence of fluorine-based systems and significance of their nascent non-covalent chemistry in molecular assemblies are presented in a brief review of the field. Emphasis has been placed to show that type-I and -II halogen-centered F···F long-ranged intermolecular distances viable between the entirely negative fluorine atoms in some fluoro-substituted dimers of C6H6 can be regarded as the consequence of significant non-covalent attractive interactions. Such attractive interactions observed in the solid-state structures of C6F6 and other similar fluorine-substituted aromatic compounds have frequently been underappreciated. While these are often ascribed to crystal packing effects, we show using first-principles level calculations that these are much more fundamental in nature. The stability and reliability of these interactions are supported by their negative binding energies that emerge from a supermolecular procedure using MP2 (second-order Møller-Plesset perturbation theory), and from the Symmetry Adapted Perturbation Theory, in which the latter does not determine the interaction energy by computing the total energy of the monomers or dimer. Quantum Theory of Atoms in Molecules and Reduced Density Gradient Non-Covalent Index charge-density-based approaches confirm the F···F contacts are a consequence of attraction by their unified bond path (and bond critical point) and isosurface charge density topologies, respectively. These interactions can be explained neither by the so-called molecular electrostatic surface potential (MESP) model approach that often demonstrates attraction between sites of opposite electrostatic surface potential by means of Coulomb’s law of electrostatics, nor purely by the effect of electrostatic polarization. We provide evidence against the standalone use of this approach and the overlooking of other approaches, as the former does not allow for the calculation of the electrostatic potential on the surfaces of the overlapping atoms on the monomers as in the equilibrium geometry of a complex. This study thus provides unequivocal evidence of the limitation of the MESP approach for its use in gaining insight into the nature of reactivity of overlapped interacting atoms and the intermolecular interactions involved.

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