What’s MeSH?
MeSH is the abbreviation of Medical Subject Headings, which aims at describing bio-medical concepts with standardized terms. It is manually edited by NIH which determines a MeSH heading for each article after reading its full text. Among that, topic headings describing the main idea of an article are called Major Topic Headings while those describing an aspect of the topic are called subheadings.
Why we need MeSH?
There may be different descriptions for the same concept. For example, the two terms of Tumor and Neoplasm exactly have the same meaning. Therefore, when an inquirer wants to search articles about the relations between tumor and diet, he may input Tumor or Neoplasm as keyword, and actually there is no different between the two terms. Sometimes a retrieval system doesn’t recognize that, but except PubMed which can accurately recognize that with MeSH so as to avoid any omission of retrieval results. Formulating MeSH is to adopt fixed expressions for the same concept so as to control the vocabulary and to facilitate the communication between bio-medical scholars.
MeSH Homepage
You can find the latest MeSH vocabulary on its homepage http://www.nlm.nih.gov/mesh/. RefNavigator also includes a local MeSH vocabulary browser. It’s more fast since all words are loaded from local file instead of from network.
Here are two small but useful Pubmed tips:
(1) How to locate Pubmed website
At first I always use URL http://www.ncbi.nlm.nih.gov/pubmed/ to access Pubmed. It’s a little difficult to remember- actually sometimes I need to google “Pubmed” to find the URL address.
Tips: there is another simple URL: www.pubmed.org. Obviously it’s much easier to remember.
(2) “AND” is different to “and”
On Pubmed website, all search terms will be converted to lower cases by default. In other words, it’s same to search “cdna” or “CDNA”. But it does apply to logic operators.
For example, the following two queries will return different results:
- “cdna and mrna”
- “adna AND mrna”
The first query, “cdna and mrna”, actually will search in all fields for three words “adna”, “and” and “mrna. While the second query, “adna AND mrna” is really what you want. Pubmed will look for those articles that all fields include “adna” and “mrna”.
Yes, what I want to say is, always use upper cases “AND” “OR” when you try to connect different search terms.
What’s the difference between Pubmed and MEDLINE? It’s really a tricky and frequently asked question from biomedical researchers.
MEDLINE (Medical Literature Analysis and Retrieval System Online) is a literature database of life sciences and biomedical information. It is the world’s most comprehensive source for that area - the database has more than 18 million records from approximately 5,200 selected publications from 1950 to the present. MEDLINE is maintained by the National Library of Medicine (NLM). Each record in MEDLINE is manually indexed with NLM’s controlled vocabulary, the Medical Subject Headings (known as MeSH).
Pubmed is a web-based literature retrieval service and it is also provided by NLM. Pubmed provides access to lots of biomedical literature databases, and MEDLINE is the largest one among those databases. By default, Pubmed will search your terms in all of those databases. But you can also limit your search to MEDLINE only - just select MEDLINE from the Subsets menu on the Limits screen of Pubmed search interface.
According to NLM’s fact sheet, Pubmed provides following supplements in addition to MEDLINE records:
- In-process citations which provide a record for an article before it is indexed with MeSH and added to MEDLINE or converted to out-of-scope status.
- Citations that precede the date that a journal was selected for MEDLINE indexing (when supplied electronically by the publisher).
- Some OLDMEDLINE citations that have not yet been updated with current vocabulary and converted to MEDLINE status.
- Citations to articles that are out-of-scope (e.g., covering plate tectonics or astrophysics) from certain MEDLINE journals, primarily general science and general chemistry journals, for which the life sciences articles are indexed with MeSH for MEDLINE.
- Some life science journals that submit full text to PubMed Central® and may not yet have been recommended for inclusion in MEDLINE although they have undergone a review by NLM, and some physics journals that were part of a prototype PubMed in the early to mid-1990’s.
- Citations to author manuscripts of articles published by NIH-funded researchers.
Pubmed is not the only way to search MEDLINE. You can also access MEDLINE via some third-part websites or software tools. For example, you can access MEDLINE through website EBSCO (http://www.EBSCO.com), which offers an optional graphic display of your search results.
And please don’t forget to try our product RefNavigator. RefNavigator can automatically group MEDLINE search results, show SCI Impact Factor for each record and download full-text PDF files. Furthermore, it can directly insert records into Microsoft Word and automatically generate bibliographies with different journal styles. You can view our Pubmed tutorial for RefNavigator here.
Now we can draw a conclusion. PubMed is just a gateway service to access MEDLINE. It provides lots of additional resources, but it’s not the only way to access MEDLINE.