Induced-matter theory

D. E. Koshland and J. T. Edsall have recorded their own experiences in early protein research. Koshland stresses the value of his induced fit theory,192 while Edsall describes his long career at Harvard after two years with Hopkins at Cambridge.193 Fruton has also described the work of T. B. Osborne (1859-1928), noted for his analyses of amino-acids from seed proteins.194 The idea that enzymes might be proteins was a matter of heated debate among chemists from about 1915, including arguments between Willstatter and James Sumner, who in 1926 isolated the enzyme urease and showed it to be a protein.195 However, while it is most important to emphasize protein chemistry, the contributions made to protein science by physics... 

Virtually every survey of the Scientific Revolution highlights the importance of Boyle s mechanical philosophy, but the precise relationship of this doctrine to the immediate matter theory that it replaced has until now received uniformly short shrift. Few historians have appreciated the fact that the mechanical philosophy, as formulated by Robert Boyle, was itself the capstone to a preexisting tradition employing alchemy to recast scholastic theories of mixture, an attempt at reform whose roots extended well into the Middle Ages. Nor does one find a common awareness of the fact that Boyle s most significant experimental evidence for the persistence of microlevel corpuscles and for the mechanical character of the accidental qualities induced upon and removed firom those corpuscles stemmed from the reduction to the pristine state originating in the alchemical tradition and made famous in the early seventeenth century by Daniel Sennert. 

This chapter discusses the apphcation of femtosecond lasers to the study of the dynamics of molecular motion, and attempts to portray how a synergic combination of theory and experiment enables the interaction of matter with extremely short bursts of light, and the ultrafast processes that subsequently occur, to be understood in terms of fundamental quantum theory. This is illustrated through consideration of a hierarchy of laser-induced events in molecules in the gas phase and in clusters. A speculative conclusion forecasts developments in new laser techniques, highlighting how the exploitation of ever shorter laser pulses would permit the study and possible manipulation of the nuclear and electronic dynamics in molecules. 

Lind [2] has defined radiation chemistry as the science of the chemical effects brought about by the absorption of ionizing radiation in matter. It should be distinguished from radiation damage which refers to structural transformation induced by irradiation, particularly in the solid state. The distinction is not always maintained, perhaps unconsciously, and sometimes both effects may be present simultaneously. Following a suggestion of M. Curie around 1910, that ions were responsible for the chemical effects of radioactive radiations, the symbol MjN was introduced to quantify the radiation chemical effect, where M is the number of molecules transformed (created or destroyed) and N is the number of ion pairs formed. Later, Burton [3] and others advocated the notation G for the number of species produced or destroyed per 100 eV (= 1.602 x 10 J) absorption of ionizing radiation. It was purposely defined as a purely experimental quantity independent of implied mechanism or assumed theory. 

Ionization of atoms or molecules is the main primary event induced by the interaction of radiations with condensed matter. The charged species produced by ionization, if not removed from the irradiated system, will naturally tend to recombine. The conventional theories of recombination treat the transport and reactions of charged species only after the electrons ejected from atoms or molecules become thermalized by dissipating their initially high kinetic energies to the surrounding medium and form a spatial distribution around their parent cations. The thermalization in condensed phases is fast and is usually... 

This concludes the theory of collision-induced line shapes of binary systems, that is the line shape that one might observe at gas densities that are not too high - with one exception near zero frequency the intercollisional dip will always be present, no matter how low the pressure may be. The absorption dip is a many-body effect and is not obtainable from a binary theory (Poll 1980). At low gas densities, the intercollisional process appears only over a very small frequency interval near zero, of the order of the mean collision frequency, and it can in general be readily distinguished from the binary profile which extends over a much greater range of frequencies. 

The authors of this book started working on chemical kinetics more than 10 years ago focusing on investigations of particular radiation - induced processes in solids and liquids. Condensed matter physics, however, treats point (radiation) defects as active particles whose individual characteristics define kinetics of possible processes and radiation properties of materials. A study of an ensemble of such particles (defects), especially if they are created in large concentrations under irradiation for a long time, has lead us to many-particle problems, common in statistical physics. However, the standard theory of diffusion-controlled reactions as developed by Smoluchowski... 

This book is the first attempt to summarize, probably from our subjective point of view, the state of the art in a very rapidly developing theory of many-particle effects in bimolecular reactions in condensed matter, which up to now was a subject of several review papers only [1—10]. We have focused mainly on several basic bimolecular reactions trying not to cover all possible cases (e.g., more complicated reactions, cooperative processes in alloys under irradiation [11] or initial macroscopic separation of reactants, etc.) but to compare critically results and advantages/limitations of numerous approaches developed in the last years. We focused on processes induced by point particles (defects) only the effects of dislocation self-organization are discussed in [12-16] whereas diffusion-limited particle aggregation with a special attention to fractal cluster formation has extensive literature [17-21],... 

From a more practical point of view, the major problem with the incentive-sensitization theory of drug addiction is the lack of evidence for its occurrence in the human addict. Thus, Volkow et al. (1997b) showed that in cocaine postaddicts no behavioral (as expressed by drug-induced high) or biochemical sensitization (as expressed by drug-induced increase of extracellular DA in the striatum) can be demonstrated. As a matter of fact, a decrease in these measures was observed. These observations put a major question mark on the validity of the DA sensitization theory as an explanatory framework of drug addiction. 

Previous Reviews. A general survey of the effects of molecular interactions on the optical properties of matter was recently given by Buckingham [435]. The work concerning ab initio and approximate computations of pair polarizabilities has recently been reviewed by Hunt [80] a careful comparison of the data available from various measurements reveals a high degree of consistency with the fundamental theory. Hunt has also reviewed the utility of the DID model and its limitations [79]. The results of measurements of the polarizability invariants of rare-gas pairs have been reviewed by one of the authors [271]. Substantial discussions of induced polarizabilities can be found in a number of review articles on CILS and dielectric properties [11,27, 143, 274, 343, 376]. 

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