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CHEM6611: Scientific Communication in Chemistry


3c.CAS Lexicon Building Blocks in SciFinderⁿ [SciFinder-n]

Overview of library resources supporting graduate research

CAS Lexicon

Use the CAS Lexicon when you design a "building blocks" search in SciFindern. The Lexicon, an updated version of the Chemical Abstracts Index Guide, lists descriptive terms assigned to references:

  • Concepts
  • General Subject terms
  • Biological organism genus and species names
  • Substances (those most frequently indexed by CAS) and alternative names

You can add up to 1,000 terms from the Lexicon to a search query.

Note: Although SciFindern includes references from the PubMed database, the CAS Lexicon does not include PubMed's Medical Subject Headings (MeSH) or Supplementary Concepts. Find those terms in the MeSH Database and enter them directly into the SciFindern References search box.

Find Terms in CAS Lexicon

Within SciFindern, click the Search CAS Lexicon button to open the Lexicon in a new tab.

Search CAS Lexicon button

Type in a search term and click the "Search Concept" button.

Photoredox catalysis entered in the CAS Lexicon search box. Search Concept button outlined in red.

CAS Lexicon Thesaurus

The CAS Lexicon displays results in order:

  1. Exact match to a "Preferred Term" (current descriptive term)
  2. Partial matches to Preferred Terms
  3. Exact and partial matches to synonyms, alternative names, and superseded descriptive terms

Thesaurus display, described below

In this example, CAS Lexicon displays the Preferred Term “Photochemical redox catalysis” followed by a link to synonyms. Users can select two Broader Terms in the thesaurus hierarchy:

  • Photocatalysis
  • Redox reaction catalysis

Users can select two Related Terms from the thesaurus:

  • Photochemical redox reaction
  • Photochemical redox reaction catalysts

Combine Terms with OR

The CAS Lexicon doesn't "explode" terms. In other words, it will not expand Preferred Terms to include associated Narrower Terms in your search. You can click the "Select All" option or examine Narrower Terms and select your choice of terms. You can also select Related Terms. Once selected, click the "Add Term(s)" button Add Term(s) button and use the default OR operator to move selections over to Your Query, .

SciFinder-n Your Query box combines photochemical redox catalysis with multiple terms about photochemical redox catalysts, using the OR operator. Further description below.

In the thesaurus structure underlying this example, more specific (narrower) terms are indented .

  • Photochemical redox reaction catalysts [hierarchy branch 1]
    • Photochemical reduction catalysts
      • Photoelectrochemical reduction catalysts
  • Photochemical redox reaction catalysts [hierarchy branch 2]
    • Photooxidation catalysts
      • Photochemical autoxidation catalysts

Add Another "Building Block" with AND

To add another "building block" to your search, you can work directly within the CAS Lexicon, or create multiple query sets to combine in a References search.

Within the CAS Lexicon

Use this approach when you don't need to include terms from every level of the thesaurus. Select multiple terms from a single Preferred Term entry. Click the AND operator in the pull-down menu.

Thesaurus display, described below. AND operator outlined in red.In this example, "Photochemical redox catalysis" is already part of Your Query. The new terms selected are:

  • Preferred Term: Amines
  • 781 Narrower Terms
  • All 3 Related Terms. Amination, Amino group, and Aminolysis

Click Add Term(s), and run your search.

Your Query box. AND operator precedes newly added Preferred Term and counts of the Narrower Terms and Related Terms selected.

Create Multiple Query Sets

Use this approach when you need to include multiple Preferred Terms as well as their Narrower Terms from multiple levels of the thesaurus. In the example above, this technique captures results of fully expanding the list of Narrower Terms for "Amination" and for "Amino group."

Create separate queries for each Preferred Term and its Narrower Terms, using the OR operator each time. Save each set of search results. Combine the saved sets from the SciFindern search page, using the "References" search option.