A Rational Approach for the

Pilkington, Melanie, A Rational Approach for the Self-Assembly of Molecular Building Blocks in the Field of Molecule-Based Magnetism, 7, 275. 

A quantitative understanding of certain primary combustion phenomena, e.g., liquid fuel-droplet vaporization and burning, gas phase chemical reaction kinetics, radiation heat transfer from combustion products, and mixing of reactants and combustion products, is required to develop a rational approach for the effective utilization of synfuels in industrial boiler/furnace systems. Those processes are defined by the interaction of a number of mechanisms which are conveniently described in terms of physical and chemical related processes. The physical processes are ... 

Rist, B., Wieland, H.A., Willim, K.D. Beck-Sickinger, A.G. (1995) A rational approach for the development of reduced-size analogues of neuropeptide Y with high affinity to the Yi receptor. J. Pept. Sci. 1, 341-348. 

A rational approach for the decision-making process for the selection of an appropriate treatment of a flexible pavement with asphalt base is shown in the flow chart in Figure 15.30. 

Industrial scale polymer forming operations are usually based on the combination of various types of individual processes. Therefore in the computer-aided design of these operations a section-by-section approach can be adopted, in which each section of a larger process is modelled separately. An important requirement in this approach is the imposition of realistic boundary conditions at the limits of the sub-sections of a complicated process. The division of a complex operation into simpler sections should therefore be based on a systematic procedure that can provide the necessary boundary conditions at the limits of its sub-processes. A rational method for the identification of the subprocesses of common types of polymer forming operations is described by Tadmor and Gogos (1979). 

The system is regarded as commensurate if there is a rational value for the ratio a=al2iT=L/N, where a denotes the mean space of the particles, 27t is the potential period, and L indicates the number of potential periods within the calculation window. By using different combinations of L and N, one may be able to alter the commensurability of the system, which will become incommensurate when a approaches an irrational value. The golden mean, a=( /5- l)/2 144/233, for example, is usually chosen to characterize a typical incommensurate case. 

Neurotransmitter receptors have evolved as one of the key components in the ability of the central nervous system to coordinate the behaviour of the whole animal, to process and respond to sensory input, and to adapt to change in the environment. These same receptors are therefore ideal targets for drug action because of their central role in the activity of the nervous system. A rational approach to the development of new therapeutic strategies involving the action of drugs at receptors in the nervous system is based on knowledge of receptor structure, distribution and function. 

The resulting coumarin derivatives were isolated with >99% purity using the automated LC/MS purification system. Although there were neither rational explanation nor deduced structure-photophysical property relationships, this study successfully demonstrated the application of a combinatorial approach for the development of novel fluorescent compounds. The systematic transformation of... 

It is hoped that this volume will contribute toward the ultimate elucidation of the molecular mechanism of induction of cancer by PAH. This knowledge will provide a rational basis for the design of approaches for the prevention and cure of this dread disease. 

Cross [19] advocates a rational approach in the design process. He described in his book the seven steps procedure for the rational method for new design shown in Fig. 12.8-1 and listed in Table 12.8-1. The method covers every aspects of the design process from problem clarification to detailed design. It also facilitates better teamwork and enables better task subdivision. The project team employed this method to guide the design of the indoor air quality control appliance. 

A rational approach in the development of drug targeting carriers for endothelial cells in inflamed tissue is to identify disease-induced target epitopes in these cells [54,55]. As discussed in Sections 7.2.1 and 7.3, in this respect E- and P-selectin, VCAM-1 and ICAM-1 are considered candidate target epitopes. 

The toxicology of a solvent is determined by many factors, such as bioavailabihty, metabolism, and the presence of structural features that may attenuate or enhance the reactivity of the parent molecule. Despite the structure-activity data available for many classes of commercial chemical substances, chemists have not recognized the use of structure-activity relations as a rational approach for choosing or designing new, less toxic commercial chemical substances. With qualitative structure-activity relationships, comparing the structures of the substances in the series with corresponding effects on the toxicity makes the correlation between toxic effect and structure. Through these, it may then be possible to predict a relationship between structure and toxicity... 

Successful scale-up of the tableting process also requires control of the raw materials used in compaction. Typically, pharmaceutical excipients vary in their physicochemical properties, which result in batch-to-batch variations. The tableting process, especially direct compression processes where there is limited raw material alteration before compaction, is susceptible to raw material variation, which may be magnified upon scale-up. Compaction science affords the ability to fingerprint raw materials, including the drug substance, to determine if the same compaction properties will be observed from batch to batch. This also allows for a rational approach for determining alternate vendor sources of the same materials. 

With a basic mechanism at hand, a rational approach for designing catalysts with desired properties becomes possible. However, despite progress in the direct observation of surface intermediates using high pressure, realistic in situ spectroscopic methods and deeper insight into basic reaction processes, the capability of rationally designing an electrocatalytic surface with a set of desired properties has not yet fully been achieved. 

SARs have been used for decades by medicinal chemists in the design of highly efficacious drug substances [47] and by the US Environmental Protection Agency (EPA) for assessing the toxicity of new, untested commercial chemicals prior to commercialization [i.e., chemicals submitted to the EPA in the form of Premanufacture Notifications (PMNs)] [48]. However, despite the structure-activity data available for many classes of commercial chemical substances, the use of SARs has been given much less attention by chemists as a rational approach for designing new, less toxic, commercial chemical substances. 

A search for antimetabolites, i.e. analogues of essential metabolites that might displace the latter in vital processes, was proposed as a rational approach to the discovery of antibacterial agents, but it has had little success other than the achievements in the folic acid field (Section 1.06.6). Substances that resemble the components of nucleic acids have, however, had considerable success in the chemotherapy of cancer and of some virus diseases and in the suppression of the immune response. They may act by becoming incorporated in false nucleic acids or by blocking the synthesis of nucleic acids, nucleotides, nucleosides or of the pyrimidine and purine bases cytosine (88), thymine (89 R = Me), adenine (90) and guanine (91 X = CH). The simplest antimetabolites are analogues of these bases. 

Another way was used to synthesize pentathiepinoindoles <2001T7185>. Thus, the reactions of 2-lithiated indole and 1-methylindole with elemental sulfur were studied, leading, for example, to a rational approach to the corresponding pentathiepino[6,7-A]indoles 126 and 127. Treatment of the anions of the corresponding indoline-2-thiones with sulfur also gave both pentathiepinoindoles (Scheme 27). Pentathiepino[6,7-A]indole 126 can be isolated from reaction of P4S10 with isatin in pyridine (Scheme 27) <1994TL5279>. 

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