Structure-based chemical data systems development

Source characterization results are not located in a centralized facility which is constantly updated. The Environmental Protection Agency has established the Environmental Assessment Data System (EADS) (31) which contains chemical compositions of particulate matter emissions tests. This existing computerized structure can provide the centralized location for receptor model source characterization information. Procedures such as those described for ambient data in the previous section need to be developed in order to allow receptor model users access to this data base over telephone lines. The data required of receptor model source tests should be incorporated into the EADS, and source characterization results should report this information in an EADS compatible format. 

CE and for developing methods based on chemical structures and retained chromatographic knowledge. Package is integrated with ACD/Spec Manager (MS, NMR, IR, UV-Vis) and with ACD database for log P, log D, and pKa. Able to import data from major chromatography data systems. HPLC system for automated method development ... 

Because the program is still under development, final decisions have not been made as to the content, type, and structure of the data bases to be developed. Preliminary information indicates that the implementation strategy is to develop a network of on-line information systems concerning chemical substances. This network, called Chemical Substances Information Network (CSIN), will have seven subsystems ... 

This article provides a survey of quantum chemical studies on the structure and properties of isolated DNA bases and their hydrogen-bonded and stacked pairs. Recent developments of computer hardware and software have allowed electron correlation to be considered even for very large systems, leading to a qualitative improvement in the accuracy of calculated properties. Experimental characterization of isolated bases and base pairs is very difficult, and only a limited number of reliable studies are available. There is still only one published gas phase experiment on the energetics of H-bonded nucleic acid bases, from the end of the 1970s, and experimental data on base stacking are absent the same is true for the structure of bases and base pairs. High-level quantum chemical calculations thus represent the only tool to obtain reference data on the structure, properties, and interactions of nucleic acid bases. These data help to properly understand the function and properties of nucleic acids and are exceptionally important for verification and/or parametrization of empirical potentials... 

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