Hit list

If the query provides thousands of hits, the analyze features are particularly advantageous. One method is to analyze the results by any of the criteria that arc listed, c.g., by language (default), author names, journals, puhlication year, and so on. If one specification is selected and the choice is modified, the hit list will be updated. A more specific analysis is available with the Refine" option. where the user has the opportunity to choose one of eight criteria (including the search topics above) with further individual input. Several refinements of the hit list can reduce the result to a concise list of literature. To read the abstract of an article, the microscope button (to the right of the citation) has to be pressed (Figure 5-15). 

With this query 1 16 hits were found in the CIRX databases. The first hit of this hit list is shown in Figure 5-25. 

Figure 5-25. First record of the hit list of the reaction substructure search (MDC number RXCI91107130).

To obtain more information on each reaction of the hit list, it is possible to browse through the hit list, classify it (sec Section 5.13.4), print it, and export all the references on the hit list or save the reactions in different file formats for documentation purposes. 

By applying the BROAD classification feature to the hit list of the first example, described in Section 5.13.2, 18 clusters arc found, llic second reaction instance of the first cluster is shown in figure 5-30. 

The next example shows how different search queries can be combined to shed more light onto a series of related reactions. A reaction substructure search for reactions that break a P-O bond provided 304 reactions as hits. Figure 10.3-27 shows one of the reactions in this hit list. 

The four queries were examined against a list of samples tested on Whelk CSP that constitutes our search domain. Search results are summarized in Table 4-3. Of the 616 3D structures in this database list, 370 fit at least one of the query (one sample may fit more than one query) and 335 are given as resolved according to chromatographic data or information reported in the field comment. Query 2 retrieved the largest number of compounds with a high percentage of resolved samples in the hit list. While the number of hits retrieved with Query 1 is lower, this query provided a similar proportion of resolved samples (93 %). 

When the user clicks on an identified concept the UltraLink creation process is called and displays a menu of possible links. Figure 31.2C shows the list of links that are generated at run time when the user clicks on Psoriasis (second document in the hit list in Fig. 31.2A), which has been classified as a disease. It can clearly be seen how the internal logical structures from the previous section are exposed to the user when calling the UltraLink (Fig. 31.2, B and C). 

An searchable element-concentration-criteria may consist of a minimum concentration, a maximum concentration or a concentration range. After searching is complete, a hit list is displayed, from which more information about any listed CRM can be selected. For further information contact referens )telia.com... 

As seen from the case studies described in the previous sections, many investigators use multiple complementary methods to reduce and refine their hit lists to manageable numbers. Often, an inspection step is included, which places a de facto upper bound to the size of the hitlists that are reviewed. 

Test a substantial number of compounds. VS methods generally offer enrichment, but most ranked hit lists contain a significant proportion of false positives. Hitlists should be scaled to 1-5% of the compounds in the virtual library screened. In many real world situations, the computational chemist is being asked to choose lists of compounds representing 0.1% or less of the compounds screened (e.g., the best 100 of 100,000 compounds). Typically, VS methods have been validated considering 1%, 5%, or 10% of the total number of compounds in the VS collection. By following up on more compounds, one increases the probability of impact from VS. 

Automate. Much of the human effort in VS arises at the point of combining various hit lists, followed by scoring and selection. The more this can be automated, the more efficient the VS experiment becomes. 

Number of hits Number of resolved samples % of resolved samples in the hit list... 

Hit rate = (number of true actives in hit list)/(number of compounds in hit list) X100. Yield = (number of true actives in hit list)/(number of true actives in full database) X100. 

Risk ratio greater than 1.0 among hits at all hit levels. Risk ratio equals the percent of hits listing the ADR divided by the baseline percentage. 

Giiner, O. F. and Henry, D. R. Formula for determining the goodness of hit lists in 3D database searches. At URL http //www.netsci.orp/Science/Cheminform/ feature09.html. 

Reprioritizing compounds rather than eliminating some of them completely from hit-lists. 

January 15 Colombia extradites four drug traffickers to the United States. The Medellm cartel responds by creating a hit list of U.S. diplomats, businesspersons, and journalists. 

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