Structures Dissimilar

If the surfactants have a more dissimilar structure or if the counterion is different with the same surfactant ion (e.g., sodium dodecyl sulfate and calcium dodecyl sulfate), the Krafft temperature of the mixture can be much less than either pure component (87—89) These systems show the classical eutectic type behavior and the crystals contain only one kind of surfactant or counterion in substantial amounts (87-89). 

One of the most important practical aspects of protein binding is the fact that drugs of similar or markedly dissimilar structure may compete for the same binding sites on the protein (7). Hence, multidrug therapy may lead to alteration in the plasma concentration and the rate of elimination of drugs, because of multiple competition for the plasma protein-binding sites. 

In cases in which drugs exert their actions by interacting with specific receptors, structural modification dramatically alters the expected effects. However, not all drugs act by interacting with specific receptors. For example, general anesthetics such as thiopental, halothane, cyclopropane, and nitrous oxide have vastly dissimilar structures. 

Holliday JD, Ranade SS, Willett P, A fast algorithm for selecting sets of dissimilar structures from large chemical databases, Quant. Struct-Act. Relat., 15 285-289, 1996. 

Holliday, J.D., Ranade S.S. and Willett, P. A Fast Algorithm for Selecting Sets of Dissimilar Structures from Large Chemical Databases. QSAR, 1996,15,285-289. 

Table 12 shows the relative retention time date for the separation of a five-component mixture containing dissimilar structures. 

Sello, G. (1998). Similarity Measures Is it Possible to Compare Dissimilar Structures J.Chem. Inf.Comput.Sci.,38,691-701. 

Chemical Structure Aminoglycosides are antimicrobial agents with dissimilar structures it is impossible to represent aminoglycosides with a single general structure. The following is the structure of streptomycin ... 

Crystallography of two cationic complexes which result from substitution of chloride in (30) with triphenylphosphine were found to have dissimilar structures. The structure of the hexa-fluorophosphinate is similar to the neutral complexes (C—S bond = 177 pm) while the perchlorate is unusual (C—S bond =168 pm). This shortening of the C—S bond in the perchlorate is accompanied by a lengthening of the M—C bond (15 pm) and is probably due to the influence of the perchlorate ion on crystal packing. The M—S bonds of both types of sulfur compounds are significantly longer than the M—C bonds (9-33 pm) which is consistent with sulfur s longer covalent radius. 

Note that diamond and a metal like copper have quite dissimilar structures, although both are based on a face-centered cubic Bravais lattice. To distinguish between these two, the terms diamond cubic and face-centered cubic are usually used. The industrially important semiconductors, silicon and germanium, have the diamond cubic structure. 

However, when the two pendant groups are of dissimilar structure, amorphous fluoroelastomers are realized (4). 

Nonuniform Surface Temperature. The previous section was devoted to uniform-temperature plates. In practice, however, this ideal condition seldom occurs, and it is necessary to account for the effects of surface temperature variations along the plate on the local and average convective heat transfer rates. TTiis is required especially in the regions directly downstream of surface temperature discontinuities, e.g., at seams between dissimilar structural elements in poor thermal contact. These effects cannot be accounted for by merely utilizing heat transfer coefficients corresponding to a uniform surface temperature coupled with the local enthalpy or temperature potentials. Such an approach not only leads to serious errors in magnitude of the local heat flux, but can yield the wrong direction, i.e., whether the heat flow is into or out of the surface. 

The manner in which these moieties occur within the asphaltene fraction must, for the present, remain largely speculative. The asphaltenes are a solubility class (12, 35) and, as such, may be an accumulation of thousands of (similar/dissimilar) structural entities. Hence, caution is advised against combining a range of identified products into one (albeit hypothetical) structure. For example, it would be presumptuous (if not ludicrous) to suggest... 

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