TOXNET
HELP TEXT - -LactMed
Contents
HOW THE SYSTEM SEARCHES FOR AND DISPLAYS RECORDS
LACTMED CONTENT AND FIELD MNEMONICS
In the query
box, enter one or more terms (e.g., phenobarbital)
which describe your search topic. These may be any combination of words,
chemical names, brand names, and numbers, including Chemical Abstracts Services
(CAS) Registry Numbers (RN). Common "stop words" such as
"a," "an," "for," "the," and
"it," although you may enter them, will not be searched.
Examples of
search terms:
The term(s)
entered will be searched for in all LACTMED fields.
The search
will be initiated when you click the Search button. To erase your search
term(s) and start over with a blank query box, click on the Clear
button.
If your
query consists of chemicals/drugs, TOXNET will, by default (i.e., the radio button
"Yes" is selected), expand your search by adding synonyms and
CAS Registry Numbers. Thus, if you enter "chlorpromazine," the system
will add the CAS RN 50-53-3 and synonyms such as "Fenactil"
and "Thorazine." You have the option to
turn off this feature by selecting the button "No." This will
result in a search only for the exact word(s) you entered. In the example
above, the system would then look only for the word "chlorpromazine."
For typical
queries, it is suggested that you leave the synonym searching feature on
("Yes" button selected) in order to maximize retrieval. On the
other hand, if you were searching specifically for a brand name product, e.g.,
"Tylenol," and were interested only in records that mentioned the
chemical with that name, you might want to turn off synonym searching ("No"
button selected).
Clicking on
the Browse the Index button will display a segment of the LactMed index, beginning with the term you enter (e.g., amoxicillin),
and let you scan the index alphabetically (or numerically) above or below the
original display by clicking on the Up or Down button. For each
index term, the system displays the number of LactMed
records containing that term. By checking the "Check to Select" box(es) corresponding to the index
term(s) of interest and clicking on the Select button, you can search on
the selected term(s). You may browse the index to all words, CAS Registry
Numbers, or chemical names.
Databases (The Left Column of the Screen)
Clicking on
any of the cells in this column will take you directly to the search screen for
the database selected. "Multi-databases" offers simultaneous
searching of LACTMED, (LactMed listed twice) CCRIS,
IRIS, ITER, LactMed, and GENE-TOX. The question mark
symbol ("?") next to each database provides a brief description of
it, with links to a more detailed Fact Sheet and a sample record.
Support Pages (The Right Column of the Screen) � Other
tools to help with the database or its interpretation.
Your initial
retrieval is displayed as a list of chemical names, highlighted in blue and
underlined, and their CAS Registry Numbers. If your search was for a chemical
or drug (e.g., codeine) and there is a match for it in the database, the record
for this chemical, referred to as the primary chemical record, will display
first, followed by a list of other chemical records which also contain some
mention of the chemical you entered. This latter list of chemicals is displayed
according to a Relevancy Ranking algorithm. Clicking directly on any of
the items will provide a display of the Selected Record Screen, containing all
the data, for that item.
If your
query consists of words that are not chemical or drug terms, this same Relevancy
Ranking algorithm determines the order of display of all your search
results.
By checking
one or more of the numbered boxes to the left of the list of records, you can
perform operations, such as downloading, on these selections at a later time.
You can
alter your search, if you choose, directly in the query box which reappears on
this page with your search terms. Alternately, you can use the Modify Search
button, described below.
The vertical
series of buttons on the left side of the Search Results page offers a variety
of options:
Save Checked Items - This is used to create a subset of
your search results. First check the records you want to save, then click on Save Checked Items. The system confirms
the number of items you saved and lets you display just these references by
clicking on a new button - Display Saved Items - which is added to the
series of buttons.
Sort - Sort all or some of the records
alphabetically (in ascending or descending order) by substance name.
Details - Summarizes the strategy used by
TOXNET to perform your search. This will include your query terms plus any
synonyms or CAS Registry Numbers added by the system.
History - Reviews your search session by
itemizing your search statements, numbering them sequentially, and listing the
number of records retrieved. Clicking on History allows you to view
earlier search result sets or combine these sets provided they are within the
same database.
Download - You can download all or some of the
records in "brief" or "full" formats and select particular
categories of information (custom formats).
Modify Search - Return to the Basic Search screen
with your search strategy retained. You can make changes or perform a new
search at this point.
Basic Search - Return to the Basic Search screen
with the query box cleared. You can now enter a new search.
Browse Index - This feature displays a segment of
the LactMed index, beginning with the term you enter,
and lets you scan the index alphabetically (or numerically) above or below the
original display by clicking on the Up or Down button. For each
index term, the system displays the number of LactMed
records containing that term. By checking the "Check to Select" box(es) corresponding to the index
term(s) of interest and clicking on the Select button, you can search on
the selected term(s). You may browse the index to all words, CAS Registry
Numbers, or chemical names.
TOXNET Home - Return to the TOXNET Home Page.
Page Navigation - The
top and bottom of each Search Results page displays the total number of pages,
the current page number, the total number of items, and the items displayed on
the current page. You can navigate through multi-page search results by
specifying a page number and clicking on the "Go" button or by using
the blue arrows to go to the following or preceding page(s).
About the Selected Record Screen
This screen
displays the record for whichever item you selected on the Results Screen. If
you searched for a chemical/drug (e.g., codeine) and clicked on the
"Primary Record" of the Search Results Screen, you will see the Human
Health Effects data displayed, along with a Table of Contents frame on the
left. If you clicked on a different chemical/drug record, the sections of the
record best matching your query terms will be displayed (see Best Sections),
again with an accompanying Table of Contents. From the Table of Contents, you
can choose to view the entire LactMed record or
portions thereof (by expanding and contracting categories, and checking
categories and/or fields) for the chemical you selected.
If your
original search was for a term other than a chemical, any chemical record you
click on from the Search Results Screen will result in a "Best
Sections" display.
The search
term(s) you entered, as well as synonyms (if you selected to search for them),
will all be highlighted in red wherever they appear in the text of the selected
chemical/drug record.
Across the
top of the screen is a series of buttons with more options:
Next Item - Move forward for a display of the
next item (if there is one) in your search retrieval or saved items set.
Previous Item - Move backward for a display of the
previous item (if there is one) in your search retrieval or saved items set.
Search Results - Return to the Search Results
display.
Basic Search - Return to the Basic Search screen
with the query box cleared so that you can enter a new search.
Details - Displays a summary of the strategy
you specified for your search and synonyms added by the system.
Other Files - Link directly to records in other
TOXNET data or bibliographic files (e.g., HSDB, CCRIS, IRIS, ITER, TOXLINE)
containing information on your selected chemical.
Modify Search - Return to the Basic Search screen
with your search strategy retained. You can make changes or perform a new
search at this point.
Download - You can download the selected
record in "full" format and select particular categories of
information (custom formats).
Limits - Boosts search precision over the
Basic Search interface by allowing you to specify a particular field or
category of fields in which you want your search term to appear.
Browse Index - This feature displays a segment of
the LactMed index, beginning with the term you enter,
and lets you scan the index alphabetically (or numerically) above or below the
original display by clicking on the Up or Down button. For each
index term, the system displays the number of LactMed
records containing that term. By checking the "Check to Select" box(es) corresponding to the index
term(s) of interest and clicking on the Select button, you can search on
the selected term(s). You may browse the index to all words, CAS Registry
Numbers, or chemical names.
TOXNET Home - Return to the TOXNET Home Page.
HOW THE SYSTEM SEARCHES FOR AND DISPLAYS RECORDS
TOXNET
searches for your terms, in singular and plural form,
throughout all records unless you specify particular fields or restrict
the form of your terms via the "Limits" interface. The system will
automatically look for synonyms and CAS Registry Numbers of chemicals unless
you choose to disable this feature.
If you
search on multiple terms, and each record retrieved contains all the terms you
entered, the system will first display those records in which all the terms
appear in the same section of the record. These records will be followed by
records in which the terms appear in different sections of the record. If a
multiple-term search fails to retrieve any records containing all the terms
entered, the system will display the following message: "No records were
found which contain all of the search words. The following records contain at
least one of the words."
Relevancy
ranking attempts to determine which documents are most pertinent to the search,
and to place the most relevant documents first in the list of returned
documents. The ranking is based upon the number of individual search terms
occurring in a document, the number of times each search term occurs in a
document, its rarity within the database, and the nearness of search terms to
each other. Documents containing combinations of search words tend to be ranked
higher than documents having isolated occurrences of the words.
In searching
for a particular chemical, e.g., "codeine," your retrieval may
include chemical or drug records in addition to the initial matching chemical
or drug record, called the "primary" record. These additional records
appear if they contain the word "codeine." This might occur, for
example, if the chemical is a metabolite of codeine, interacts with codeine, or
has been tested along with codeine in a toxicity study.
Clicking on
any of these non-primary chemicals on the Search Results screen will display
the Best Sections, those where the chemical search term appears with greatest
frequency. The term searched appears highlighted in red.
Another
situation in which Best Sections would occur is in searching for a subject, say
"prolactin secretion." In this case,
clicking on any of the chemicals/drugs in the Search Results screen will
display the Best Sections - i.e., the sections of the records where the words
"prolactin" or �secretion� appear with the
greatest frequency.
LactMed CONTENT
AND FIELD MNEMONICS
LactMed
contains over 440 chemical records, each of which can have as many as a dozen
or so fields of data, and continues to grow. Its scope covers important aspects
of drug use during breastfeeding. LactMed data
undergo a high level of peer review � see Database
Creation and Peer Review Process. Not every chemical will contain
data in each field. A list of database fields and corresponding mnemonics may
be found at LactMed Field Descriptions.
Users seeking a finer degree
of precision in retrieval than available through either TOXNET's
standard Basic Search screen or Limits option may want to consider formulating
searches through the use of field qualifiers and/or Boolean logic.
Users seeking a finer degree
of precision in retrieval than available through TOXNET's
standard relevancy ranking methodology may want to consider formulating searches
through the use of field qualifiers and/or Boolean logic.
Field
Qualifying is a method whereby you can specify
the particular field in which you want your term searched. Thus, if you are
searching LactMed specifically for information about colustrum drug levels, you might want to limit (or qualify)
your search by specifying that only the Drug Levels field (dlev)
be searched for the word "colustrum."
The format for field qualifying consists of the search term followed by the
field mnemonic in brackets. Thus, continuing with this example, to look for
records where "colustrum" appears in the
"dlev" field, you would enter "colustrum [dlev]." The
Substance Name field mnemonic is "na." A
search for the exact chemical name "morphine" in the LactMed file, for example, would be formulated as
"morphine [na]." Be advised that when you
qualify a search by data field mnemonic, you are instructing the TOXNET system
to search precisely the field you have specified. If the search term does not
appear in the qualified field, an error message stating that "No records
were found for the search" will be generated. A list of database fields
and corresponding mnemonics for LactMed may be found
at LactMed
Fields Description.
Boolean
Searching utilizes the logical operators OR,
AND, NOT. It is a means of limiting your search of two or more terms to
criteria you specify, and is often used in conjunction with field qualifying,
described above. Logical operators must appear in upper case. Searches
containing combinations of these operators are processed with ANDs taking precedence, followed by NOTs,
and then followed by ORs. This default precedence may
be overridden with the use of parentheses, which may also be nested (i.e.,
parentheses within parentheses).
Phrase
Searching - In phrase searching, quotation
marks (" ") are included as part of the search strategy and are used
to search for two or more terms exactly the way they are entered. In LactMed, you might want to search for records containing
the phrase "partially breastfed" in the Drug Levels field. This would
be accomplished by entering the phrase and the appropriate field designator as
follows: "partially breastfed" [dlev].
Phrase searching may be used with or without field qualifying/Boolean
searching.
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