How is Quertle different? More than simple keyword searching: Quertle goes beyond simple term matching to identify the most salient information in the literature. Using a combination of linguistic methods, Quertle finds facts defined within documents, creating its own database of nearly 200 million relationships, and is able to report the ones that are relevant to your query. Quertle's approach is based on a thorough understanding of biology and chemistry and was built from the ground up to address the unique needs of this technical literature.
Power Terms™: Quertle is able to extend its extensive biological and chemical sciences underpinnings to the definition of "Power Terms" that represent a class of entities. For example, the Power Term called $Proteins represents all protein names, thus enabling unique queries such as "what $Proteins regulate cell cycle?". Try it!
Easy exploration: Quertle provides a set of useful filters directly on the results page to help you navigate and explore the results. The "Key Concepts" filter automatically lists key concepts found in the result set so you can quickly focus in on concepts of interest. When a Power Term has been included in the query, the "Key Concepts" filter presents members of the Power Term class to answer your question. For the above example, all proteins that are involved in the regulation of cell cycle will be presented.
What content does Quertle cover?
Quertle uses MEDLINE/PubMed® as provided by the US National Library of Medicine (NLM) (see Terms) and
full-text documents from BioMed Central
and Open Access articles from PubMed Central. Quertle also searches News (as reported by FierceMarkets Life Sciences and Health Care) so that you can find late-breaking information without waiting for full publication) and scientific whitepapers and research posters submitted to Quertle (contact us about submitting yours).
Additional full-text document sources are coming. Let us know what you think we should add next.
Who is behind Quertle?
Quertle has been created by biomedical scientists, chemists, and literature informatics experts, who have many decades of experience with research and finding relevant information to support that research. Leading the effort are Jeff Saffer and Vicki Burnett.
Jeff has been involved in biomedical informatics for more than two decades and has a special interest in helping people understand large volumes of data. Following his PhD from Yale, Jeff was a fellow at the National Cancer Institute and then an Associate Staff Scientist at The Jackson Laboratory. He then was Head of the Molecular Biosciences Department at the Pacific Northwest National Laboratory. Throughout his research, Jeff used informatics approaches to make the most of data. It was during his tenure at PNNL that he founded OmniViz, which focused on the visualization of biomedical data, including literature.
Vicki also has a long history of applying informatics and data analysis. She received her doctorate in molecular toxicology from the North Carolina Integrated Toxicology Program (Duke, UNC, NC State). Vicki did research at CIIT, the National Institute for Environmental Health Sciences, and the Pacific Northwest National Laboratory prior to joining the University of Arizona as Associate faculty at the Health Sciences Center. She then joined OmniViz and became a key contributor to the design of that software.
Why the ads?
Political answer: To help you find knowledge, including products relevant to your work.
Practical answer: Without the modest proceeds, we couldn't provide this site for free.
How should queries be written?
You can enter queries just like you do on the sites you are used to. Check out the examples (the View Examples link is just under the search box). In addition, Quertle can understand phrases. So, you may want to enter a query that contains a subject, verb, and object. For example, you could write "aspirin treats headache". You can also use "what" for the subject or object as in "what treats headaches?" or "aspirin treats what?". Quertle will be learning so try entering the query you really want. If the results are not what you expected, let us know.
Are queries case-sensitive?
Yes and no. For most terms, case does not matter. Some terms, however, have very different meanings when used in a particular case. For example, consider "NO" (nitric oxide) and "no" (negative), or "AIDS" (disease) and "aids" (helps). In these cases - pun intended - it is a good idea to use proper capitalization. And, for the record, font size doesn't matter.
Can I look for a specific phrase using double quotes?
No. Quertle "conceptualizes" your query to give the most relevant, and generally increased numbers of results. Quertle takes input such as "pinocytosis inhibition" and matches that to relationships, including "fluid-phase endocytosis was inhibited by" and so on. Thus, forcing a search for specific phrases is not supported. Quertle also "knows" about most things biological and chemical and will automatically recognize phrasal entities, such as "muscle contraction". If Quertle doesn't seem to understand something, please let us know.
What Power Terms can I use?
Power Terms are query terms used to represent a class of entities, such as $Diseases (representing all diseases), not the generic term "disease". The most commonly used Power Terms can be found in the Power Terms pop-up window. This can be accessed by clicking the link below the Search box. You can also view the full list of Power Terms. If there is a Power Term you think should be included, please let us know.
How do I search for an author?
Stand up and look around the lecture hall. OK, a better answer: unlike some other sites, you should not enter the author(s) of interest in the main Search Box. Please type in the author(s) of interest in the Author Search box. As you type in an author's name, a list shows some possible matches. As you type more, the list will update accordingly. You do not have to actually pick from the suggestion list if you prefer to type the entire name. You can search for multiple authors by entering more names in the Author Search box, each separated by a comma. If more than one author is entered, the results must contain all of the names.
What if I don't see the author I am looking for in the suggestion list?
Keep typing. The list cannot show all possible matches (e.g., if you are looking for "Smith") and shows the more prolific authors that match what you have typed so far. As you type further, you should see who you're looking for. If you don't, then either that person used a pseudonym or we lost them. In the latter case, please let us know.
How do I search for a specific journal?
To limit your query results to those from a specific journal, enter the journal name in the Journal Search box. As you type in a journal name, a list shows some possible matches. As you type more, the list will update accordingly. You do not have to actually pick from the suggestion list if you prefer to type the entire name. You can search for multiple journals by entering more names in the Journal Search box, each separated by a comma. When entering multiple journals, the results will be for any of the entered publications.
What if I want to search by author or journal without any other terms?
No problem. Just enter the author(s) and/or the journal(s) and leave the main Search box empty. There will, however, not be any relationship type results listed in the "Key Concepts" filter area, but all documents by that author will show up. You can further filter to a topic of interest simply by adding a term in the "Also containing" field found on the results page.
What's the difference between relationships and keywords? Relationships are conceptual facts extracted by linguistic methods from the documents. Relationships are more than just having the terms found in the same document and are based on the context and implication of the text.
Keywords are terms identified simply by identifying words - and their synonyms - in a document, regardless of whether the words are used within the same context, or even within the same section of the document.
Why are there fewer relationship results than keyword search results?
In most cases you will find fewer results on the Relationship results than on the keyword search list.
When searching for multiple terms, the Relationship results show documents that use the multiple terms
together in a meaningful way, whereas the keyword search will find more documents because the
terms do not have to be together.
Even when your search is a single term, the Relationship results only contain documents where the
term is used in a recognizable relationship.
What is the highlighting?
The terms and phrases highlighted in yellow are your query term(s). If you have added an "Also containing" filter or have clicked on a Key Concept, those terms will be in bold. If you prefer not to have the highlighting shown, click "Turn Highlighting Off" at the top of the results. To turn it back on, click "Turn Highlighting On".
How are the results ordered?
Quertle initially orders the results list according to what is most relevant to your search.
Can I reorder by date?
Yes. Simply click on "Sort by Date" at the top of the results list. The results will now sort by date, most recent first. To go back to relevance sorting, just click on "Sort by Relevance".
What does the date "Epub" mean?
Many publishers submit accepted articles to PubMed prior to their actual publication.
These articles have a publication date sometime in the future.
Quertle shows all such future dates as "Epub" (Electronic publication ahead of print)
so you don't run off to the library and wait for several months for the article to appear.
I don't see my query term(s) in a result listing. Why?
When doing keyword searches, Quertle looks anywhere in the document, not just the abstract.
For full-text documents, this includes all the informative content fields (such as
Introduction or Discussion), but not the Bibliography or other ancillary fields.
For all MEDLINE/PubMed records, or full-text articles that have a corresponding
PubMed record, the keyword search also looks in the MeSH Headings
from the PubMed record. Thus, the abstract itself may not contain all (or, in fact, any)
of the search terms and there will be nothing highlighted.
For relationship searches, all the search terms must be within the relationship.
Also Containing: You can type in additional words to be queried for in the current results set by typing into the "Also Containing" text box, then click the >> button (or by hitting Enter). If done while viewing relationship results, this will filter the document set to present papers that contain both the query concepts and the additional term within the boundaries of the relationship defined. If done from the keyword results set, papers containing the query terms and the additional term anywhere will be presented. The "Also Containing" filter always looks for the term you enter, all of its inflected forms (such as plurals), and all of its synonyms.
Published Within: Documents can be filtered by date to show only those published within defined time intervals, such as the previous 30 days. Let us know what other date ranges would be useful.
Publication Type: Documents can be filtered to show specific types of publications. Simply click on the publication type of interest. Note that clicking more than one publication type will filter the results to ANY of the selected types. To undo your choice(s), simply delete the Publication Type from the Applied Filters or click the individual entry in the Publication Type filter. Let us know what other publication types you would like to be able to filter by.
Key Concepts: One of the most useful aspects of the filter set is to limit documents to those relevant to a concept of interest. The "Key Concepts" filter section contains terms Quertle automatically identifies as key concepts in the initial results set. And when you have used a Power Term, this section presents members of the Power Terms group that are part of the identified relationships. Click on any term in the "Key Concepts" section to show only those documents containing the specific results of interest. To undo the filtering, just delete the term in the Applied Filters section.
How do I use the Applied Filters?
When you apply a filter, a "breadcrumb" is left in the Applied Filters. You can eliminate any (not just the last) filter by clicking the corresponding or by clicking the entry again in the filter section. You can also go back to a prior set of results by clicking on a breadcrumb link, which removes all filters below it. To remove all filters, click the following the Applied Filters label.
Can I apply more than one "Key Concept" filter?
No, but you can remove the current filter and choose another one simply by clicking on the next to the term in the breadcrumb trail. Or, just click on a different term in the "Key Concepts" list and the filter will change.
I know a certain object should be on the "Key Concepts" list, but it isn't. Why?
The top concepts (or members of a Power Term class) are calculated from the most relevant documents. The term you are looking for is likely far down the list of results and may not have been included in the relevant set. You may want to use a different query.
or by clicking the entry again in the filter section. You can also go back to a prior set of results by clicking on a breadcrumb link, which removes all filters below it. To remove all filters, click the