30 April 2014: New Emtree release includes changes in cell line terminology

The second (May) release of Emtree in 2014 is now available, with the addition of 720 preferred terms (including 87 drug terms) compared with the previous release in January 2014. This brings the total number of preferred terms in Emtree to 69,931. As with previous releases, all new Emtree terms have been backposted on Embase.com to bring the indexing of older records in line with the current terminology (as many of these new terms were previously indexed in Embase as candidate terms).

A list of the new terms will shortly become available on http://www.elsevier.com/online-tools/embase/emtree, where you can also find overviews of all Emtree terms added and changed since January 2011. The new terms in this Emtree release will be available for indexing from May 12, 2014.

This edition of Emtree contains some important hierarchical changes for cell lines, including tumor cells/cell lines. If you use these terms, take a moment to check the Emtree structure to ensure that your search is optimized for your needs. For example, "tumor cell line" is indexed in just under 34,000 records in Embase. Now, with this Emtree release, it has become an explosion term, with a hit count (when searched using an explosion search) of over 150,000 records. This example also shows that "tumor cell line" is no longer considered to be a "procedure", but is now exclusively found as an anatomical concept. It will therefore, in future, not be retrieved in explosion searches using broader terms such as "medical procedures".

Similarly, the term "tumor cells and cell lines" has been removed from the "diseases" hierarchy and is now listed (as a synonym to the new preferred term "tumor cell") as an anatomical concept. In this case the narrower terms, and therefore the results of an explosion search, are identical (just over 250,900 records). However, because "tumor cell" is now not considered to be a disease term it is no longer indexed with disease subheadings. Previous linkage to these subheadings is, however, left intact.

Additional improvements made in the April 30th release

A problem with the execution of free text searches has now been corrected. Previously, records were retrieved when the free text search terms were included within the broader terms of the Emtree terms indexed, so that in effect free text searches also functioned as explosion searches. These functionalities have now been separated, so that free text searches only search the fields indexed in Embase records — not the broader terms. As a result, some free text searches will produce lower results than before, e.g. 'age'.

We've also improved the Export function so that it now includes the option to export all Author addresses in addition to the Correspondence address and have made the Article Title search option available in the Article Search form again.