Role of Substrate

The substrate has long been known to play a role in the excitation of localized particle plasmons, shifting the resonant frequencies due to a change in the permittivity of the medium on which the metal nanostructures are located [28]. In addition, recent work has shown that certain substrates play an active role in light-plasmon coupling [24,27,43]. 

This effect is even more striking when compared to the field intensity which results from a more conventional, passive substrate, Si02. Simulations by Guo et al. showed that in that case the substrate perturbs the field much less strongly, resulting in a conventional dipole-like distribution for smaller particles. 

Large enhancements due to the effect of a high-permittivity substrate were also reported by D Agostino et al. [27] they studied fluorescence from CdSe/ZnS core/shell nanocrystals in proximity to silver nanospheres on an Ag-coated substrate. D Agostino demonstrated the role of this substrate in the observed enhancement by calculating the local field-enhancement factor using a Green s function refinement of the discrete dipole approximation this allowed retardation effects to be taken into account. 

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Hurst, J.L., Fang, J. and Barnard, C. (1993) The role of substrate odours in maintaining social tolerance between male house mice, Mus musculus domesticus relatedness, incidental kinship effects and the establishment of social status. Anim. Behav. 48, 157-167. 

It is interesting to note that there is no complete symmetry between the role of substrate diffusion and electron transport in their combination with the catalytic reaction, as can be seen in the structures compared in the equations and also in the fact that linear Koutecky-Levich plots are not obtained in all cases, as noted in Table 4.1. 

A final advantage of the cosputtered CCS approach is that rf bias, typically 10 W, under independent control can be supplied to the substrate as indicated in the schematic diagram (Fig. 10.2). We speculate that the role of substrate bias is to increase surface mobility during film growth. This changes the microstructure and decreases the defect density of the as-grown film, which is related to the leakage behavior of... 

T. Sooknoi and J. Dwyer, Role of Substrate s Electrophilicity in Base Catalysis by Zeolites, to be published. 

The more recent structural evidence supports the role of substrate distortion. A trisaccharide in the BCD sites of crystalline hen egg white lysozyme is distorted to the half-chair,229 as is a substrate bound to the Asp-52 — Ser mutant studied in solution by NMR.230 Protein engineering studies on the residues involved support the conclusions.231 A chitobiose bound to a crystalline chitobiase has the equivalent sugar distorted to a sofa.232... 

Kocgozlu L, Lavalle P, Koenig G et al (2010) Selective and uncoupled role of substrate elasticity in the regulation of replication and transcription in epithelial cells. J Cell Sci 123 29-39... 

Different solvents have been used, such as chlorobenzene[314] or dichloroethane,191 but very often the arene plays the dual role of substrate and solvent.191115 173... 

P. Favia, R. Lamendola, R. d Agostino The role of substrate temperature and bias in the plasma deposition from tetramethylsilane. Plasma Sources Sci. Technol. 1, 59 (1992)... 

Reid and Schey studied the role of substrate composition and other factors in the formation and performance of films on various metal substrates, including copper, aluminium, titanium and mild steel, tested against themselves and against an alloy steel. They used a twist-compression test to assess performance, and concluded that substrate hardness and composition had the greatest influence on film formation and life. They believed that film formation and especially durability are improved by chemical reaction if a substrate, such as copper or iron, has a strong tendency to react to form a sulphide, provided that the reaction kinetics are favourable. However, they found no direct evidence of reaction or of sulphide formation. Their conclusions were based on the fact that the durability of the films was found to be in the sequence aluminium, titanium, iron, copper, which is the same as the order of the free energies of formation of their sulphides. 

This decrease, observed in CPGs, is somewhat limited even for material domains as big as 100 nm. However, it must be noted that most studies on radiolytic hydrogen production at the surface of nanoporous material have been conducted on silica-based systems, and the exact role of substrate chemistry has still to be deciphered. 

Note that 5 is directly proportional to and and inversely proportional to and These dependencies of 5 clearly emphasize the role of substrate diameter and slurry viscosity, density, and velocity. It is also noted that these concepts apply in the absence of the abrasive particles which can penetrate the boundary layer and change the above formulaism. Abrasive-slurry fluid interface, on the other hand, will also suffer from similar boundary layer issues. Applied pressure, usually transmitted to the substrate or pad via the abrasive particles that separate the two, will also affect the boundary layer stability. 

Benzofuroxan reacts with benzo[6]furan-3(2//)-oncs to give a product at an oxidation level lower than the expected di-lV-oxide in a process where benzo[A]furan-3(2//)-one plays the dual role of substrate as well as reductant during the reaction, and redox processes determine the structure of the products,This is a general, one-step synthesis of 2-(2-hydroxyaryl)-quinoxaline 4-oxidcs, c.g. formation of 3. ... 

The calculated barrier to reaction in chorismate mutase was 17.8 kcal/mol, compared to 42 kcal/mol in the gas phase. Factors other than substrate distortion also play an important part in reducing the barrier to reaction in the enzyme important interactions were identified by a simple decomposition analysis (as described in sections 6.1 and 6.2 above). It was found that Glu78 and Arg90 specifically stabilize the transition state, relative to the bound substrate [8]. Overall, therefore, catalysis in chorismate mutase can be rationalized in terms of a combination of substrate strain and transition state stabilization. While it is possible to analyse all these catalytic effects as arising from maximal binding in the enzyme being achieved at the transition state, it appears useful to separate the different types of contribution. The possible role of substrate destabilization/distortion or strain in lowering the barrier to reaction in enzyme reactions, as put forward by Haldane [219], and invoked in... 

Barlow, P. N., Lister, M. D., Sigler, P. B., and Dennis, E. A. (1988). Probing the role of substrate conformation in phospholipase A2 action on aggregated phospholipids using constrained phosphatidylcholine analogues, y. Biol. Chem. 263, 12954—12958. 

Schiros T, Takahashi O, Andersson K, Ostrom H, Pettersson LGM, Nilsson A, and Ogasawara H (2008) The role of substrate electrons in the wetting of a metal surface. J Chem Phys (submitted)... 

Many studies in the realm of microbiology (B36, M6, N26, R25) have emphasized the role of substrate and hormone induction of enzymes. It is not surprising, therefore, that similar mechanisms have been searched for, have been found, and are being studied in mammalian systems. 

There has been considerable interest in recent years in the formation of condensed films of purine and pyrimidine bases at the solid-liquid interface. It is well recognised that non-covalent affinities between base pairs play a prevalent role in determining nucleic acid conformation and functionality. Likewise, there has been interest in the role of substrate and non-covalent intermolecular interactions in the configuration of ordered monolayers of purine and pyrimidine bases. There is also more general interest in the interaction of bases with metal surfaces and metal complexes. In the latter case it is noted that the biological role of nucleic acids and certain nucleotides are dependent on metal ions, particularly Mg, Ca, Zn, Mn, Cu and Ni. " Also certain metal complexes, notably of platinum, have the anti-tumour activity, which is linked to their ability to bind to bases on DNA. On a different note, the possibility that purine-pyrimidine arrays assembled on naturally occurring mineral surfaces might act as possible templates for biomolecular assembly has been discussed by Sowerby et al. 

Large kinetic isotope effects in enzymatic proton transfer and the role of substrate oscillations, Proc. Natl. Acad. Sci. USA 1997, 94, 12360-12365. 

Morphology of the Metal-Organic Semiconductor Contacts The Role of Substrate Surface Treatment... 

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