Stability force

Jarvis S P, Durig U, Lantz M A, Yamada H and Tokumoto H 1998 Feedback stabilized force-sensors a gateway to the direct measurement of interaction potentials Appl. Phys. A 66 S211... 

Pigment dispersions are stabilized by charge repulsion and entropic, ie, steric or osmotic, repulsion. Although both types of stabilization force may be present in most cases, for pigment dispersions in solvent-bome coatings entropic repulsion is usually the most important mechanism for stabilization. 

To avoid the instabilities of wedge-shaped oils films, a lubricating film can be maintained by the application of pressurized oil (or, occasionally, air) to the bearing. The hydrostatic bearing maintains a continuous film of oil even at zero speed, and induces a strong stabilizing force towards the center that counteracts any displacement of the shaft or spindle. Disadvantages include the power... 

It follows from Eqs. (73) and (74) that the only stabilizing force for a-modes at long X is the membrane tension, and critical voltage vanishes as cr 0. In experiments with black lipid membranes the surface tension a arises from the contact of the bilayer with the bulk phase contained in the surrounding rim and is typically < 0.002 N/m. Then choosing... 

For saturated pool boiling on vertical surfaces, the Weber number (a ratio of dynamic force to the stabilizing force) alone determines the stability of a rising bubble ... 

Upon biosynthesis, a polypeptide folds into its native conformation, which is structurally stable and functionally active. The conformation adopted ultimately depends upon the polypeptide s amino acid sequence, explaining why different polypeptide types have different characteristic conformations. We have previously noted that stretches of secondary structure are stabilized by short-range interactions between adjacent amino acid residues. Tertiary structure, on the other hand, is stabilized by interactions between amino acid residues that may be far apart from each other in terms of amino acid sequence, but which are brought into close proximity by protein folding. The major stabilizing forces of a polypeptide s overall conformation are ... 

What is the main stabilizing force in the secondary structure of proteins ... 

The third class of host defense peptides, the extended peptide class, is defined by the relative absence of a defined secondary structure. These peptides normally contain high proportions of amino acids such as histidine, tryptophan, or proline and tend to adopt an overall extended conformation upon interaction with hydrophobic environments. Examples of peptides belonging to the extended class include indolicidin, a bovine neutrophil peptide, and the porcine peptide fragment, tritpticin. These structures are stabilized by hydrogen bonding and van der Waals forces as a result of contact with lipids in contrast to the intramolecular stabilization forces found in the former peptide classes. 

Alternative stabilizing forces (Z) include (i) complexation with metal alkyls (or hydrides), forming hetero-and homodinuclear complexes such as [Cp 2M-(/i-Me)2AlMe2] Y and [(Gp 2M-Me)2(/i-Me)] Y (Figure... 

Woodward, P. (19976). Octahedral tilting in perovskites II. Structure stabilizing forces. Acta Cryst. B53, 44-66. 

Matrix metalloproteinase structural studies of the P -side inhibitors to date show a common set of inhibitor-enzyme interactions. This can be attributed primarily to the strong directional zinc-binding forces. Further stabilizing forces from the backbone hydrogen-bonding patterns common to a (3 sheet allow for minor adjustments due to the zinc interactions to be made while maintaining a common pharmacophore. 

About 200 to 460 kJ/mol are required to break a single covalent bond, whereas weak interactions can be disrupted by a mere 4 to 30 kJ/mol. Individual covalent bonds that contribute to the native conformations of proteins, such as disulfide bonds linking separate parts of a single polypeptide chain, are clearly much stronger than individual weak interactions. Yet, because they are so numerous, it is weak interactions that predominate as a stabilizing force in protein structure. In general, the protein conformation with the lowest free energy (that is, the most stable conformation) is the one with the maximum number of weak interactions. 

Overturn Couple or Lever Arm. The distance between the center of gravity and the center of pressure is known as the overturning couple or the lever arm, and thru this the stabilizing forces deriving from spin operate. Since neither of these two centers lies exactly on the axis (due to normal manufg errors) the result is yaw. The... 

This study, therefore, presents a novel method for enhancement of hydrophobic forces and a sensitive method for detecting this effect. A properly constructed experiment using D20 and H20 solutions may also be used to measure the relative contribution of the several stabilizing forces in systems of biological interest. 

Amide resonance is a powerful stabilizing force and gives rise to a number of structural effects. Unlike the pyramidal arrangement of bonds in ammonia and amines, the bonds to nitrogen in amides lie in the same plane. The carbon-nitrogen bond has considerable double-bond character and, at 135 pm, is substantially shorter than the normal 147-pm carbon-nitrogen single-bond distance observed in amines. 

Base-stacking interactions are an important stabilizing force in nucleic acid structures. Describe how base stacking contributes to the tertiary structure of the tRNA molecule. 

The observed equilibrium thickness represents the film dimensions where the attractive and repulsive forces within the film are balanced. This parameter is very dependent upon the ionic composition of the solution as a major stabilizing force arizes from the ionic double layer interactions between any charged adsorbed layers confining the film. Increasing the ionic strength can reduce the repulsion between layers and at a critical concentration can induce a transition from the primary or common black film to a secondary or Newton black film. These latter films are very thin and contain little or no free interlamellar liquid. Such a transition is observed with SDS films in 0.5 M NaCl and results in a film that is only 5 nm thick. The drainage properties of these films follows that described above but the first black spot spreads instantly and almost explosively to occupy the whole film. This latter process occurs in the millisecond timescale. 

Enzymes are a class of macromolecules with the ability both to bind small molecules and to effect reaction. Stabilizing forces such as hydrophobic effects only slightly dominate destabilizing forces such as Coulombic forces of equal polarity thus the Gibbs free enthalpy of formation of proteins, AGformation, is only weakly negative. 

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