Command-Line Searching (Syntax)
- Boolean operators (AND / OR / NOT/NEAR/NEXT)
- Phrase searching
- Proximity operators
- Wildcards (truncation)
- Searchable fields and field labels
Embase allows you to conduct “deep searching” of the biomedical literature with a sophisticated command-line search syntax. This option offers great flexibility and control in query-building, and is a powerful alternative for experienced searchers who prefer this style of searching to “point-and-click.”
Search queries in the Session Results page appear in command-line format, letting you see exactly how your search was executed.
Combination searches can be used to manipulate search sets; use the search set numbers with a hash mark (#). Search sets can also be nested with parentheses.
#3 OR #5
(#1 and #2) NOT #3
Free text searches can done without field labels, mapping or quotes. This is a “broad” way to search and is often helpful for a first look at an unfamiliar concept. If no quote marks are used in a multi-word phrase, Embase searches it with AND, and finds the words anywhere in a database record:
gene therapy retrieves gene AND therapy
Restriction to specific fields is done with a colon (:) and a two-letter field label. You can search individual fields, or combine several (separated with commas):
Exact search in designated fields is done with an Emtree term folllowed with a slash (/) and two-letter field label:
Fields available for exact phrases:
de Index (Emtree) term
dd Drug index term
dm Medical index term
au Author name
jt Journal title
ta Abbreviated journal title
exp Explosion search
mj Major index term
Exact searches retrieve only the term specified; ‘heart’/de only finds record indexed with heart, not heart disease, heart valve, etc.
These fields and codes can be combined with slashes:
Map to preferred terminology refers to matching of synonyms to Emtree preferred index terms (Emtree thesaurus terms); it automatically runs exact searches (above) using de, dd, dm, mj, exp and subheading searches (e.g., dm_su).
Subheadings are searched as two-letter qualifier codes with drug terms (dd) or medical terms (dm). See drug subheadings, routes of drug administration and disease subheadings. They can be searched alone or in groups (separated with commas); major or explosion can also be added. They are all done as exact searches, as noted above.
Subheadings can also be searched alone as “free-floating” or "floating" subheadings; e.g., not attached to a specific index term, with lnk.
‘adverse drug reaction’:lnk
prevention:lnk and /py
Explosion searches are mapped searches of index terms that automatically capture all narrower (more specific) terms within their hierarchical Emtree thesaurus structure.
‘eye injury’/exp finds cornea injury, eye burn, traumatic cataract, etc.
Limits are indicated with square brackets ([ ]) instead of quotes, and usually /lim. They are used with dates and with qualifiers from the More Limits sections of the Drug, Disease and Advanced Search forms; they include publication types, areas of focus, languages, patient age groups, gender, etc.
Date limits use /py (publication year range), /sd (‘since date’) and /wd (‘within date’). Formats for /sd and /wd and YYYY/MM/DD.
Reviews on AIDS published within the last 5 years
‘aids’mj AND [review]/lim and [2005-2009]/py
Papers by oncologist J.C. Smith indexed since mid-2002
‘smith j.c.’ AND [cancer]/lim and [01/07/2002]/sd
Articles from the last 14 days from the journal Cell
‘cell’/jt AND /wd