Unsolved basic problems

Concept The basic concept is to study cell biological phenomena with an approach originating from organic chemistry. Based on structural information available for a given biological phenomenon unsolved chemical problems are identified and new synthetic pathways and methods are developed. This new chemistry then is used to synthesize tools for subsequent biological investigations. If... 

To understand the biological function of proteins we would therefore like to be able to deduce or predict the three-dimensional structure from the amino acid sequence. This we cannot do. In spite of considerable efforts over the past 25 years, this folding problem is still unsolved and remains one of the most basic intellectual challenges in molecular biology. 

How much detail does a student need to know and how much detail should a textbook then contain This is an almost unsolvable problem because of the diversity of students and their analytical needs. The majority of students will eventually move on into special fields in (bio)chemistry, molecular or systems biology or polymer chemistry. For them mass spectrometry will only be one of the commodities to help them solve their problems, which are defined by their field of activity, not the analytical technique. How much of the basics in mass spectrometry will they need to know Again, this depends on the problem at hand. For many a routine application of commercial instalments and the manufacturers manuals will suffice. However, if the problem is not routine the analytical technique cannot be either. Mass spectrometry is and, most probably, will remain a rather complex technique. To fully exploit its tremendous potential, but, equally important, to avoid its many pitfalls, a deeper understanding of the mechanisms and the technology will be mandatory. This book will, hopefully, help students to lay the basis for this expertise and, once the need arises, allow them to go back to the more specialized literature at a later time. It is in this sense that I hope this book will be a real help to many of them. 

Theoretical considerations based upon a molecular approach to solvation are not yet very sophisticated. As in the case of ionic solvation, but even more markedly, the connection between properties of liquid mixtures and models on the level of molecular colculations is, despite all the progress made, an essentially unsolved problem. Even very crude approximative approaches utilizing for example the concept of pairwise additivity of intermolecular forces are not yet tractable, simply because extended potential hypersurfaces of dimeric molecular associations are lacking. A complete hypersurface describing the potential of two diatomics has already a dimensionality of six In this light, it is clear that advanced calculations are limited to very basic aspects of intermolecular interactions,... 

Basically, however. Ihe problem of w arm fog clearing remains unsolved. 

Some of the unsolved problems in contemporary electrodynamics draw attention to deeper (more profound) evidence, new ideas and new theories or equations. The aim of this historical introduction is to find the deeper evidence and new basic concepts and connections. The guiding principle is the investigation of light propagation. 

The IPCC (2005) report gives a general characteristic of various aspects of the GCC emphasizing the special features of individual regions and highlighting unsolved problems. The report notes that at the present state of humankind development the basic anthropogenic C02 sources are ... 

To meet this demand I compiled in this supplement additional problems with detailed solutions, problems that are quite similar to those in the text. In addition, I have added numerous unsolved problems with answers (a frequent request for homework problem assignments). Each set of problems conforms to the arrangement in my book "Basic Principles and Calculations in Chemical Engineering, 6th edition, published by Prentice Hall, Englewood Cliffs, N.J. The notation used in the problems and solutions is the same as in the textbook. 

The synthesis of primary alkenylphosphines has been accomplished utilizing the same rDA method that was used to synthesize primary enamines. The synthesis of primary alkenylphosphines had been an unsolved problem owing to the high reactivity of the phosphine group under acidic, basic and neutral conditions. The preparation of vinylphosphine (38a) and isopropenylphosphine (38b) by FVP of the apprc riate anthracene (37) or 1,3-diphenylbenzofuran (39) adduct has been accomplished as shown in equation (26). ( )-Prop-l-enylphosphine was synthesized by a similar rDA route. These phosphines were found to be surprisingly stable, with a half-life of approximately 8 d for (38a). 

This molecule is structurally more flexible than DNA. The database of resolved three-dimensional RNA structures is much smaller than that for proteins it contains only a few hundred molecules. Modeling three-dimensional structures of RNA is basically an unsolved problem, however, there are effective methods for modeling two-dimensional RNA structures. We do not discuss modeling RNA structures in this book and refer the reader to [6],... 

C3 cyclopolymerization has not yet been finished and has still some interesting unsolved problems as mentioned in this paper. A few of initial objects, however, have been accomplished. That is, it gave the new material which has high n-basicity due to cyclophane units. The future progress is hoped to present further more novel materials produced by the principle of C3 cyclopolymerization where the attractive interaction between cationic site and aromatic n-system functions during the polymerization. 

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