Inhibition interface

Specific formulation strategies need to be employed for macromolecule compounds. An excellent review of protein stability in aqueous solutions has been published by Chi et al. (92). In addition to solution stability of proteins and peptides, aerosolization may result in significant surface interfacial destabilization of these compounds if no additional stabilization excipients are added. This is due to the fact that protein molecules are also surface active and adsorb at interfaces. The surface tension forces at interfaces perturb protein structure and often result in aggregation (92). Surfactants inhibit interface-induced aggregation by limiting the extent of protein adsorption (92). 

It was pointed out in Section XIII-4A that if the contact angle between a solid particle and two liquid phases is finite, a stable position for the particle is at the liquid-liquid interface. Coalescence is inhibited because it takes work to displace the particle from the interface. In addition, one can account for the type of emulsion that is formed, 0/W or W/O, simply in terms of the contact angle value. As illustrated in Fig. XIV-7, the bulk of the particle will lie in that liquid that most nearly wets it, and by what seems to be a correct application of the early oriented wedge" principle (see Ref. 48), this liquid should then constitute the outer phase. Furthermore, the action of surfactants should be predictable in terms of their effect on the contact angle. This was, indeed, found to be the case in a study by Schulman and Leja [49] on the stabilization of emulsions by barium sulfate. 

Fig. 8 shows a primer formulated with a corrosion-inhibiting pigment such as a chromate. As discussed previously, some permeability to moisture is necessary for these pigments to dissolve and be transported to the interface where passivation of the substrate can occur. Optimum performance is generally found at PVC/CPVC Just below 1 [71]. 

The molecular structure and dynamics of the ice/water interface are of interest, for example, in understanding phenomena like frost heaving, freezing (and the inhibition of freezing) in biological systems, and the growth mechanisms of ice crystals. In a series of simulations, Haymet and coworkers (see Refs. 193-196) studied the density variation, the orientational order and the layer-dependence of the mobilitity of water molecules. The ice/water basal interface is found to be a relatively broad interface of about... 

Chemical reaction This involves the formation of distinct compounds by reaction between the solid metal and the fused metal or salt. If such compounds form an adherent, continuous layer at the interface they tend to inhibit continuation of the reaction. If, however, they are non-adherent or soluble in the molten phase, no protection will be offered. In some instances, the compounds form in the matrix of the alloy, for example as grain-boundary intermetallic compound, and result in harmful liquid metal embrittlement (LME) although no corrosion loss can be observed. 

Na+-dependent inactivation. There is a sequence of 20-aminoacids (219-23 8), located in the intracellular f loop near the membrane lipid interface, that seems to be involved in the Na+-dependent inactivation. This autoinhibitory 20-aminoacid sequence might interact with another portion of the f loop (562-679) producing NCX inhibition. In accordance with this view, the synthetic peptide provided with the same sequence of XIP region blocks NCX activity. 

Oxazolidinones are a new class of synthetic antimicrobial agents, which have activity against many important pathogens, including methicillin-resistant Staphylococcus aureus and others. Oxazolidinones (e.g. linezolid or eperezolid) inhibit bacterial protein synthesis by inhibiting the formation of the 70S initiation complex by binding to the 50S ribosomal subunit close to the interface with the 3OS subunit. 

The catalytic activity of doped nickel oxide on the solid state decomposition of CsN3 decreased [714] in the sequence NiO(l% Li) > NiO > NiO(l% Cr) > uncatalyzed reaction. While these results are in qualitative accordance with the assumption that the additive provided electron traps, further observations, showing that ZnO (an rc-type semi-conductor) inhibited the reaction and that CdO (also an rc-type semi-conductor) catalyzed the reaction, were not consistent with this explanation. It was noted, however, that both NiO and CdO could be reduced by the product caesium metal, whereas ZnO is not, and that the reaction with NiO yielded caesium oxide, which is identified as the active catalyst. Detailed kinetic data for these rate processes are not available but the pattern of behaviour described clearly demonstrates that the interface reactions were more complicated than had been anticipated. 

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