Detailed molecular characterization

The present study provides another example (11) of the importance of detailed molecular characterization in understanding and controlling the chemical/physical phenomena involved in... 

Structural and thermodynamical aspects of the phase separation, domain theory, were presented in 1967 to the International Rubber Conference (21) in the United Kingdom and to a symposium (18) at the California Institute of Technology later in the year. Network properties of the A-B-A polymers were also described (18). Following the commercial announcement in 1965 and the meetings in 1967, there was an explosion of requests for samples of S-B-S and S-I-S products. We then prepared laboratory samples and offered these along with detailed molecular characterization data to outside research workers for study. 

A detailed molecular characterization of the human NAPRT was reported only recently, and it was shown that the activity of this enzyme (in contrast to NMPRT) is not a subject of feedback inhibition by the physiological levels of NAD. This finding may provide a rationale for the observation that the increased levels of Na, but not Nm, in circulation leads to the increase in the NAD cellular pool, emphasizing the different roles of these two forms of niacin in nutrition and signaling in mammals (for a review, see Bogan and Brenner ). 

The cDNA and corresponding primary amino acid sequences of several CPRs including rat , rabbit- , and human were obtained by the mid-1980s, and the development of Escherichia coli expression systems paved the way for detailed molecular characterization of the polypeptide through site-directed mutagenesis. The three-dimensional structure of rat CPR was determined by X-ray crystallography in 1997 by Kim and coworkers -, providing the structural prototype for dual flavin oxidoreductases. 

Our most recent work on fatty acids in Conception Bay [117] has provided additional details to the overall observations made for bulk carbon and individual hydrocarbons discussed above. We combined detailed molecular characterization with carbon isotopic measurements to describe both the temporal and depth variations of primary production during the spring bloom. The isotopic compositions of the fatty acids are summarized in Fig. 9. Bulk spring bloom particulate organic matter in Conception Bay has a 6 C value between -24%o and -26%o [116]. Since lipids are normally expected to be depleted relative to... 

In this study we have characterized a 20 kDa polypeptide by a combination of biochemical and molecular genetical approaches and demonstrated that it is the chlorophyll binding apo-polypeptide of CP24. In addition we have isolated cDNA clones for the entire precursor protein which has allowed a detailed molecular characterization of the chlorophyll-protein and its biogenesis. 

Torri C, Garcia Alba L, Samori C, Fabbri D, Brilman DW. Hydrothermal treatment (HTT) of microal-gae detailed molecular characterization of HTT oil in view of HTT mechanism elucidation. Energy Fuels 2012 26 658. 

This book is divided up into sections. The first three chapters provide a background sections that follow contain chapters dealing with polymer chain analysis, polymer morphology and structure, polymer degradation, polymer product analysis and support techniques. These are listed in more detail in Chapter 1, which also expands more fully on our industrial perception of the requirements for competence and appreciation in all techniques and methods for polymer molecular characterization and analysis. We hope you find this book of value and its approach both unique and technically informative and useful. 

A vital activity of the chemical sciences is the determination of structure. Detailed molecular structure determinations require identifying the spatial locations of all of the atoms in molecules, that is, the atomic distances and bond angles of a species. It is important to realize that the three-dimensional architecture of molecules very much defines their reactivity and function. However, molecules are dynamic, a feature that is not reflected by static pictures. This last point requires further explanation. Because the atoms in all molecules move, even in the limit of the lowest temperatures obtainable, molecular structures really describe the average position about some equilibrium arrangement. In addition, rotations about certain bonds occur freely at common temperatures. Consequently, some molecules exist in more than one structure (conformation). Some molecules are so floppy that structural characterizations really refer to averages among several structures. Yet other molecules are sufficiently rigid that molecular structures can be quite precisely determined. 

The chemical and physical properties of ribosomes are well characterized (for reviews see The exact understanding of their function, however, still lacks a detailed molecular model. Appropriate methods such as image reconstruction from electron micrographs of two-dimensional sheets, or X-ray structure analysis, all depend on the crystallizability of the material. 

Professor Ubbelohde s suggestions are certainly worthwhile. But there are many directions that we are trying to pursue more detailed studies of the conformation of the polymers, introduction of new functional groups, macro molecular characterization by hydrodynamic methods, and so on. If I were a professor at Imperial College, I could assign all these problems, and those you suggest, to members of the staff but I am constrained by a smaller research group. 

Surface and interfacial phenomena of importance in mineral processing are reviewed. Examples of a fundamental and an applied nature are taken from the recent literature to illustrate how the use of several different surface characterization techniques makes it possible to delineate a detailed molecular-scale picture of interfaces. Lack of... 

While important for the quantitative characterization of adsorption processes, adsorption studies provide only a phenomenological description of the process and do not generally reveal much in the way of a detailed molecular picture of the resulting organo-mineral composite. 

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