Retrieval criteria

Substructure searching, whether in 2D or in 3D, provides an invaluable tool for accessing databases of chemical structures. It does, however, have several limitations that are inherent in the retrieval criterion that is being used, which is that a database record must contain the entire query substructure in precisely the form that it has been specified by the user (subjea to any variations that have been specified, e.g., a distance tolerance or a range of acceptable substituent types for a specific position on a ring system). 

It is necessary to estabUsh a criterion for microbial death when considering a sterilization process. With respect to the individual cell, the irreversible cessation of all vital functions such as growth, reproduction, and in the case of vimses, inabiUty to attach and infect, is a most suitable criterion. On a practical level, it is necessary to estabUsh test criteria that permit a conclusion without having to observe individual microbial cells. The failure to reproduce in a suitable medium after incubation at optimum conditions for some acceptable time period is traditionally accepted as satisfactory proof of microbial death and, consequentiy, stetihty. The appHcation of such a testing method is, for practical purposes, however, not considered possible. The cultured article caimot be retrieved for subsequent use and the size of many items totally precludes practical culturing techniques. In order to design acceptable test procedures, the kinetics and thermodynamics of the sterilization process must be understood. 

A clear and explicit measure of the quality of the signal, obtained after retrieval, should be available, to be used as a criterion for guiding the compression. 

A. The certified poison center or system shall keep records of all cases handled by the center in a form that is acceptable as a medical record. This criterion will be considered to be met if the Center completes a record that contains data elements and sufficient narrative to allow for peer review and medical and/or legal audit, and such records are retrievable. 

Request. Initially, the developer requests the reuse interface for support. The interface is embedded inside PRIME and, is thus able to retrieve the actual situation of the developer s work that is an important criterion for the identification of the relevant stored traces. 

After an initial model is retrieved, the molecule is manipulated by addition, removal, and changing of the atom type. The decision for the sequence of optimization steps is dynamically adapted to the properties of the RDF descriptor, the chosen atomic properties, and the similarity criterion. The following properties are altered ... 

Diverse sets of inhibitors were compiled manually for eleven well-established pharmaceutical targets. The main - subjective - selection criterion was to cover as many different compound classes as possible for each target. Compounds were retrieved from the WDI and from available complex crystal structures in the PDB [75]. Where patent literature was consulted in addition, references are given in the following list. The final data set consisted of ... 

The computer program ELBT of the CD version of this book permits the retrieval of data tables using any single or combined search criterion based on chemical system (a single component or the binary mixture), the vapor-liquid equilibrium property type, and/or the reference (authors, original source of data, and/or year range)... 

The identified articles were screened by date, titles and abstracts of all retrieved references. The search was limited to articles, written in English, since 2004 to present. Electronic copies of articles were also identified. The articles retrieved for this review of the electronic databases were comphed with the following inclusion criterion relationship between sound levels and hearing loss. 

Another fundamental problem following the molecular formation determination from the constituent atoms is the individuality combined with the universality of the constituent species being combined in the molecular assembly, i.e., the transferability of the atomic species properties from one molecule to another. For example, how are they retrieved or how much properties of the atomic species are retrieved in the series of hydrocarbon One needs to create a methodology to find a criterion on... 

Two types of distance criterion can be used in options 1 and 3. The first of these is used when the pattern is known to contain secondary structural elements that are separated by large distances, i.e., greater than 10 A in this case, the user can specify a distance error for the distance between the mid-points of the axes fines. Alternatively, if the distances between the elements are small, i.e., less than 10 A, the distance error can be specified for the closest approach distance. The tolerances can be expressed as absolute quantities, e.g., a certain number of A, or as a proportion of the the distance concerned, e.g., 10%. In practice, the closest approach distance has been found to be more effective for retrieving secondary structures that interact with each other in some sense, e.g., neighbouring pairs of P-strands in a sheet, or helices in van der Waals contact with each other. However, the mid-point distance appears more appropriate for the case where the secondary structure elements are more remote from one another in the structure. The user can also specify whether or not the order that the secondary structure elements occur along the protein chain is important in the search for a particular query motif... 

An infinite number of different similarity measures for matching two mass spectra is possible. In reality, about a dozen similarity criteria have been described and tested however, full details of the algorithms that are actually implemented in commercial software are seldom described. Some similarity criteria are purely mathematically oriented, others are influenced by spectroscopic ideas. A single criterion cannot fit all requirements on the one hand, a compound which is contained in the library should be retrieved even if the spectrum deviates in some parts from the reference spectrum on the other hand, the user expects hits with chemical structures similar to the unknown even though they exhibit different spectra. In the ideal case the similarity criterion has a practicable sensitivity to chemical structures identical compounds measured under different spectroscopic conditions appear more... 

If the creep behavior of an adhesive or adhesive joint meets this criterion, the -l/a and b parameters can easily be retrieved by linear regression. The factor b is proportional to the initial load applied to the specimen (elastic properties of the adhesive) and the slope parameter a relates to the relaxation properties of the adhesive. 

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