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TOXNET HELP TEXT - ITER

 

Contents

 

SEARCH SCREEN

 

 

SEARCH RESULTS

 

 

SELECTED RECORD SCREEN

 

 

HOW THE SYSTEM SEARCHES FOR AND DISPLAYS RECORDS

 

 

ITER CONTENT

 

 

ADVANCED SEARCHING FEATURES

 

 

RECOMMENDED BROWSERS

 

 

 

 

SEARCH SCREEN

 

ITER Search for Benzene

 

Entering a Search Query

In the query box, enter one or more terms (e.g., benzene), which describe your search topic. These may be any combination of words, chemical 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 ITER 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.

Synonym Searching

If your query consists of chemicals, 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 "perchloroethylene," the system will add the CAS RN 127-18-4 and synonyms such as "tetrachloroethylene" and "tetrachloroethene." 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 "perchloroethylene."

Browse the Index

 

[Screen Shot 2 � Browse for Hexachlorobenzene]

[Screen Shot 3 � Results of Browse for Hexachlorobenzene]

 

Clicking on the Browse the Index button will display a segment of ITER, beginning with the term you enter (e.g., hexachlorobenzene), 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 ITER 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 HSDB, CCRIS, IRIS, ITER, and GENE-TOX. The information icon ("i") next to each database provides a brief description of it, with links to a more detailed Fact Sheet and a sample record.

 

Other NLM Resources, Support Pages� (The Right Column of the Screen)

 

You may also visit additional NLM Web-Based Resources:

Or Support Pages:

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SEARCH RESULTS

 

About Your Search Results

 

ITER Search Results for Benzene

 

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 (e.g., benzene) 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 terms, this same Relevancy Ranking algorithm determines the order of display of all your search results, with the most relevant results displaying first.

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 .

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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 HSDB 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 HSDB 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).

 

SELECTED RECORD SCREEN

 

About the Selected Record Screen

 

ITER Record for Benzene

 

This screen displays the record for whichever item you selected on the Results Screen. If you searched for a chemical (e.g., benzene) and clicked on the "Primary Record" of the Search Results Screen, you will see the full ITER record, along with a Table of Contents frame on the left. If you clicked on a chemical record other than the primary one, 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 ITER 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 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., CCRIS, IRIS, 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 a particular category of information (custom format).

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 HSDB 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 HSDB 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. The system will automatically look for synonyms and CAS Registry Numbers of chemicals unless you choose to disable this feature.

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����������� Multiple Terms

 

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."

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Relevancy Ranking

 

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.

 

����������� Best Sections

 

In searching for a particular chemical, say "benzene," your retrieval may include chemical records in addition to the initial matching chemical record, called the "primary" record. These additional records appear if they contain the word "benzene." This might occur, for example, if the chemical is a metabolite of benzene, interacts with benzene, or has been tested along with benzene 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. In addition, if you search for a chemical, such as �arsenic�, which appears in ITER as �arsenic, inorganic,� then a Best Sections display will result for �arsenic, inorganic.��

Another situation in which Best Sections would occur is in searching for a subject, say "teratogenicity." In this case, clicking on any of the chemicals in the Search Results screen will display the Best Sections - i.e., the sections of the records where the word "teratogenicity" appears with the greatest frequency.

ITER CONTENT

 

ITER contains over 620 chemical records, each of which has four sections of data:� noncancer oral, cancer oral, noncancer inhalation, and cancer inhalation.� Each of these sections provides a summary table of risk data, a synopsis explaining the table and differences in risk values derived by different organizations, and a further information section providing additional details and links to each organization�s Web Site.� ITER provides both risk data and cancer classifications.� Definitions and abbreviations can be found in the ITER Glossary.

 

Summary Table

A green check indicates there is data available, while a double dash indicates that data is not available.

Clicking on an organization name or acronym (e.g. ATSDR) will take you to that organization's home page on the Web.

Clicking on the "i" next to the organization name or acronym will take you to a brief description of the organization in the "ITER Definitions" list.

 

Risk Data

Risk data includes a table representing the particular type of risk (noncancer oral; cancer oral; noncancer inhalation; cancer inhalation) under discussion, followed by a synopsis summarizing the results therein, and then followed by specifics related to values derived by each organization.

 

 

ADVANCED SEARCHING FEATURES

 

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.

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.� 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).

 

Truncation � The asterisk (*) may be freely used as a truncation symbol standing for any number of characters. Searching in ITER for "spin* � will retrieve records with words such as spine, spinal, spino, and spinally in the Human Toxicity Excerpts field. Truncation may be used with or without Boolean searching.

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 HSDB, you might want to search for records containing the phrase "liver failure.�� It would be entered just that way, within parentheses.� Phrase searching may be used with or without Boolean searching..

 

RECOMMENDED BROWSERS��

 

TOXNET is best viewed with Internet Explorer 4.0 or Netscape 4.0 or higher versions, for either PC or Mac.