Synergistic enhancement

As another example, a synergistic enhancement of tensile strength has been reached in blends of a sulfo-nated polyacrylonitrile terpolymer (SPAN) with a polyurethane (PU) cationomer [23]. Maximum enhancement was achieved at a blend composition of 30/70 (PU/ SPAN). At this blend composition, the tensile strength was raised from an initial value of 78.5 MPa to 196 MPa and the strain-to-fracture was at its highest. The en-... 

The efficiency of the antioxidant will depend on the ratio of the rates of Reaaion 2.10 to those for Reactions 2.11 and 2.12. A compound that is capable of reducing the antioxidant radical (A ) back to the parent compound (AH) will compete with Reactions 2.11 and 2.12, and so increase the efficiency of peroxyl radical scavenging (Reaction 2.10). In addition, the steady-state concentration of the antioxidant wiU be maintained at its initial concentration for a longer period and this should also result in more efficient suppression of the peroxidation reaction. The net result of these effects will be a synergistic enhancement of antioxidant activity. 

Further synergistic enhancement of amide resonance and H-bonding occurs when both monomers can participate in two complementary H-bonds, once as a Lewis base and once as a Lewis acid. Such concerted (cooperative) pairs of H-bonds occur in the cyclic formamide dimer, as illustrated in Fig. 5.20. In this case the strength of each H-bond is further enhanced (to 6.61 kcalmol-1, about 4.7 times that of the prototype (5.31c)), the bond orders ben and bco are further shifted (to 1.384 and 1.655, respectively), and the bond lengths undergo further shifts in the... 

J. Liang, Y. Jiao, M. Jaroniec, S. Z. Qiao, Sulfur and nitrogen dual-doped mesoporous graphene electrocatalyst for oxygen reduction with synergistically enhanced performance, Angew. Chem. Int. Ed., vol. 51, pp. 1-6, 2012. 

Ahmmad, B. Kusumoto, Y. Somekawa, S. Ikeda, M., Carbon nanotubes synergistically enhance photocatalytic activity of Ti02. Catal. Comm. 2008,9 1410-1413. 

The 114 Kd protein PARP, exclusively found as a mixture with DNA-PK has been implicated in repair after DNA damage. Evidences show that PARP and Ku 70/86 interact together and synergistically enhance their binding to DNA (IgH MARs)... 

A recent work by Lavon et al. [74] suggests that the synergistic effect of SLS and ultrasound when applied simultaneously can also be attributed to the modification of the stratum corneum pH profile when exposed to ultrasound. The altered pH profile that results in improved SLS lipophylic solubility, together with improved SLS penetration and dispersion, can explain the synergistic enhancing effect on transdermal transport (see Figure 16.4). 

Wang L, MacDonald RC (2004) New strategy for transfection mixtures of medium-chain and long-chain cationic lipids synergistically enhance transfection. GeneTher 11 1358-1362... 

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