About this Review

To retain coherence with the more detailed descriptions found in the references, the equations and descriptions in this chapter closely follow the referenced works whenever possible. In particular, this means that the variable definitions are not uniform throughout the chapter but are defined with respect to each specific coupling methodology. Also, since it is expected that many readers will refer primarily to individual sections, several commonly used acronyms are defined more than once and a table of acronyms is included at the end of this chapter. 

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Since entropy plays the determining role in the elasticity of an ideal elastomer, let us review a couple of ideas about this important thermodynamic variable ... 

Since about 1955, a considerable number of new developments of wide synthetic, structural, and mechanistic interest have been described. It is the purpose of this review to discuss the significant features of these new advances. 

This review includes most of the published articles from the defined area and excludes only imidazoquinolines, which were reviewed in Weissberger-Taylor s series The Chemistry of Heterocyclic Compounds (81MI1). Comprehensive Heterocyclic Chemistry II (96MI1) mentioned only some of the azoloquinolines in the first edition the authors omitted citations about this type of compounds. The trend toward interest in these compounds can be illustrated by the number of citations in Chemical Abstract as shown in Table I. Besides Chemical Abstracts Substance/Subject (Collective) Indexes, the MDL database search has been used. 

To date little is known about the chemistry of triazocines. Only three of the five possible isomeric structures are relevant in the context of this review as there are no reported syntheses of the 1,2,3- (I) and 1,3,6-triazo (5) compounds. A special review on triazocines is available.1... 

The present review deals with polymerization systems where the furan ring is present in the monomer(s) either as the reactive entity or as a side group to the function responsible for the growth. It covers, therefore, a wide variety of situations, many of them not yet fully understood. In fact, as will become apparent later, there is still a great deal of controversy about the interpretation of experimental results obtained with most of these systems and sometimes even disagreement among authors as to the data obtained. Particular emphasis has therefore been placed in this review on a critical reinterpretation of previous work in view of the recent experience gathered by... 

Within the broad spectrum of systems described, only few can be considered well understood. Unfortunately, many past investigations were superficial and more involved studies have been avoided because of the inherent complex phenomenology. This has been harmful, and misleading conclusions have been reached about the real potential of furan monomers. It is hoped that this review has shown the fallacy of this approach and will therefore stimulate further skilled work in this field. 

In this review the nature of the various oxidation species in solution are reviewed and generalizations drawn about their complexing behavior. 

The number of reports about hemicelluloses that have been covered by this review indicates the significantly increased importance of all types of hemicelluloses as plant constituents and isolated polymers during the last decade. Attention has been paid not only to known hemicelluloses but also to the primary structure, physicochemical, physical, and various functional properties of hemicelluloses isolated from hitherto uninvestigated plants. The efforts to exploit a variety of plant as potential sources of hemicelluloses were pointed out particularly for agricultural crops, wood wastes, as well as for by-products of pulp and rayon fiber technologies. Many studies were devoted to characterize seed-storage hemicelluloses from plants that have been traditionally applied in food and medicine of many underdeveloped countries to find substitutes for imported commercial food giuns. 

The publishers of SCI also produce another publication, called Index to Scientific Reviews, that appears semiannually. This publication, which began in 1974, is very similar to SCI, but confines itself to listing citations to review articles. The citations come from 2500 journals in the same general areas as are covered by SCI. The review articles cited appeared in about 215 review journals and books, as well as in those journals that publish occasional review articles. Like SCI, the Index to Scientific Reviews contains citation, source, corporate, and Permuterm indexes. It also contains a Research Front Specialty Index , which classifies reviews by subject. 

Several doubts about the correctness of the usual statistical treatment were expressed already in the older literature (31), and later, attention was called to large experimental errors (142) in AH and AS and their mutual dependence (143-145). The possibility of an apparent correlation due only to experimental error also was recognized and discussed (1, 2, 4, 6, 115, 116, 119, 146). However, the full danger of an improper statistical treatment was shown only by this reviewer (147) and by Petersen (148). The first correct statistical treatment of a special case followed (149) and provoked a brisk discussion in which Malawski (150, 151), Leffler (152, 153), Palm (3, 154, 155) and others (156-161) took part. Recently, the necessary formulas for a statistical treatment in common cases have been derived (162-164). The heart of the problem lies not in experimental errors, but in the a priori dependence of the correlated quantities, AH and AS. It is to be stressed in advance that in most cases, the correct statistical treatment has not invalidated the existence of an approximate isokinetic relationship however, the slopes and especially the correlation coefficients reported previously are almost always wrong. 

The Auger effect is analogous to the internal conversion in that an atomic electron is emitted instead of the expected X-ray. Very little is well known about Auger yields in these transitions out beyond the K shell, and a more detailed discussion is outside the scope of this review. 

Most of the other silylation-activation-substitution reactions reported in this review are mechanistically related. Several new reactions (such as those discussed in Sections 7.1, 7.2, and 7.4) have been discovered by following these hnes of thinking about activation of functional groups by O-silylation and subsequent or concomitant reaction with nucleophiles giving the expected products and hexamethyldisiloxane 7. It can thus be expected that current and new silylation-activation reactions will be more commonly used in preparative chemistry in the future. 

Many reviews have been written about the antioxidant activities of carotenoids. Some also describe prooxidant activities. - In consequence, only selected points about this very broad subject will be presented in the first part of this chapter. Linked to these properties and important for food nutritional value is the stability of caro-... 

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