Specific Molecular Interaction

The redox reaction between the polyelectrolytes in PEM films and specific molecules in solutions has been used to induce responsive film swelhng. To name a few, multilayer films containing a ferrocene-derivatized polyaUylamine hydrochloride (PAH-Fc) [185] and an osmium complex-derivatized polyaUylamine hydrochlorides (PAHOs) [186] can swell by 10% of initial film thickness upon oxidation of the Os(II). Multilayer capsules with layered anionic and cationic polyferrocenylsilanes to form multilayer capsules expand and increase their per-meabihty upon chemical oxidation of the ferrocene units [187]. Additionally, a poly(L-glutamic acid)/PAH multilayer film is reported to take up ferrocyanide ions from solutions and can expand and contract by 5-10% in response to electrochemical oxidation and reduction of the ferrocyanide species [188]. 

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Levy R, Maaloum M. 2005. Specific molecular interactions by force spectroscopy From single bonds to collective properties. Biophys Chem 117 233-237. 

In summary, the apparent redox modulation of lycopene certainly affects two important redox sensitive transcription factors at higher concentrations of lycopene. However, electrophilic lycopene oxidation products cannot be ruled out as the major activators and the activation may be due to specific molecular interactions. 

All the methodology just described requires that the solubilities of the analyte and its impurities be totally additive, which implies that the solubility of any given species cannot be affected by the presence of any other dissolved substance. Such a lack of independence is most commonly indicated by the existence of curved lines when the data are plotted in the conventional manner, and it has been discussed in great detail [38]. In the presence of specific molecular interactions, the phase solubility method cannot be used without the benefit of detailed knowledge of the nature and magnitude of the interactions. Such interactions can either increase or decrease the overall solubility, and the outcome is difficult to predict a priori. A thorough investigation is required to deduce the nature of the interactions if the phase solubility method is to be used. 

Specific Molecular Interactions (Jardetzky) Nuclear Paramagnetic (Spin-Spin) Relaxation in Solids 7 499... 

Study of Specific Molecular Interactions by Nuclear Magnetic Relaxation Methods (Jardetzky). ... 

Thus, the process of olfaction in humans begins with more-or-less specific molecular interactions between the small odorant molecules, say the 200-300 in... 

The direct detection of a complex from an equilibrium mixture is certainly the most obvious evidence of specific molecular interactions between components. Electrophoresis of an equilibrium mixture is an easily performed experiment, enabling the determination of complex formation parameters. When the dissociation kinetics of the complex is slow, the complex gives rise to a new peak in the electropherogram, in addition to the peaks of the free component molecules. Since the separation of the free components prevents the reformation of the complex inside the capillary, the complex peak should decrease in size during electrophoresis. The extent of this decrease depends on dissociation kinetics and separation time. In view of that fact, short analysis times, as obtained in CE, are required to detect less stable complexes, which would hardly be detected using previous formats of electrophoresis with longer separation times. 

Polymer-mediated self-assembly of nanoparticles provides a versatile and effective approach for the fabrication of new materials. This bottom-up strategy builds up nanocomposite materials from diverse nanosized building blocks by incorporation of molecular-level recognition sites. The flexibility and reversibUity of self-assembly processes imparted by specific molecular interactions facilitates the formation of defect-free superstmctures, and it can be further explored in fields ranging from electronics to molecular biology. 

The conformational entropies of copolymer chains are calculated through utilization of semiempirical potential energy functions and adoption of the RIS model of polymers. It is assumed that the glass transition temperature, Tg, is inversely related to the intramolecular, equilibrium flexibility of a copolymer chain as manifested by its conformational entropy. This approach is applied to the vinyl copolymers of vinyl chloride and vinylidene chloride with methyl acrylate, where the stereoregularity of each copolymer is explicitly considered, and correctly predicts the observed deviations from the Fox relation when they occur. It therefore appears that the sequence distribution - Tg effects observed in many copolymers may have an intramolecular origin in the form of specific molecular interactions between adjacent monomer units, which can be characterized by estimating the resultant conformational entropy. 

Thus, although substitution generally increases the proportion of amorphous phase and leads to more disordered crystalline phases, the reverse effect can be obtained using specific molecular interactions between side groups and conjugated chains. This suggests that interaction of a CP chain with another, nonconjugated polymer could be used to orient the former. In a sense, this is what is achieved in blends (see Section II.E). 

As Paleg (lj stated, there is merit in applying different connotations to two terms, "mechanism" and "mode" of action, which often are used synonymously. When a hormone acts upon a responsive plant system, it of course enters into some direct and specific molecular interaction which results, eventually, in the manifestation of a... 

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