Minimal chemical distance determination

In this approach chemical reactions are first classified according to the minimal number of valence electrons that must be redistributed in order to convert the reacting molecules into the products of the given reaction. This is accomplished by determining the minimal chemical distance between the reactants and products. 

A common problem encountered in large chemical companies involves the distribution of a single product (30 manufactured at several plant locations. Generally, the product needs to be delivered to several customers located at various distances from each plant. It is, therefore, desirable to determine how much Y must be produced at each of m plants (Yv Y2,..., Ym) and how, for example, Ym should be allocated to each of n demand points (YmV Ym2,. Ymnl The cost-minimizing solution to this problem not only involves the transportation costs between each supply and demand point but also the production cost versus capacity curves for each plant. The individual plants probably vary with respect to their nominal production rate, and some plants may be more efficient than others, having been constructed at a later date. Both of these factors contribute to a unique functionality between production cost and production rate. Because of the particular distribution of transportation costs, it may be... 

Permeation of mAbs across the cells or tissues is accomplished by transcellular or paracellular transport, involving the processes of diffusion, convection, and cellular uptake. Due to their physico-chemical properties, the extent of passive diffusion of classical mAbs across cell membranes in transcellular transport is minimal. Convection as the transport of molecules within a fluid movement is the major means of paracellular passage. The driving forces of the moving fluid containing mAbs from (1) the blood to the interstitial space of tissue or (2) the interstitial space to the blood via the lymphatic system, are gradients in hydrostatic pressure and/or osmotic pressure. In addition, the size and nature of the paracellular pores determine the rate and extent of paracellular transport. The pores of the lymphatic system are larger than those in the vascular endothelium. Convection is also affected by tortuosity, which is a measure of hindrance posed to the diffusion process, and defined as the additional distance a molecule must travel in a particular human fluid (i. e., in vivo) compared to an aqueous solution (i. e., in vitro). 

The overall approach to determining the structure of a protein is to use computational power to take into account concurrently (1) the known sequence of the amino acids in the protein (2) the known molecular structure of each of those amino acid residues, including bond distances and angles (3) the known planar structure of the peptide group (4) internuclear distances and interresidue bond angles, as determined from NMR data (5) correlations of chemical shifts and structural features and (6) minimization of energy and avoidance of unreasonable atomic contacts. There are a number of ways to handle the computations and to derive the molecular structure, but all of them depend critically on the data supplied by NMR. 

The reaction distance [16,18,21,25] between two isomeric synthons Si (A) and S2(A) will be used as a proper tool for the construction of reaction graphs [29]. The reaction graph obtained corresponds to the minimal number of the so-called elementary chemical transformations, the number of which determines the reaction distance between the synthons SjfA) and S2(A). 

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