The literature review usually precedes a research proposal and results section. Its goals are to situate the current study within the body of literature and to provide context for the particular reader. Literature reviews are important for research in nearly every academic field.

1. Doing Literature
Search

2. Records, Files, Data

4. To Know:
Value of research
What to search
How to search

20. Baguio Gen Hosp

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National Library of Medicine
 The world’s largest biomedical library
 NLM is the producer of:
 MEDLINE
 PubMed
 MedlinePlus.gov
 Visit the National Library’s Home Page at:
 http://www.nlm.nih.gov

22. PUBMED
 Provides free access to medical database
 Links to full-text articles
 Provides Advanced search
 Links to related articles and provides
discovery tools for other data that may be
of interest.

23. PubMed’s Sponsor
 Introduction to the U.S. National Library of Medicine (NLM)
 The National Network of Libraries of Medicine®
 NN/LM Web site: http://nnlm.gov

24. What’s in PubMed
 Most PubMed records are MEDLINE citations.
 Other records include those in different stages of
processing (including records provided directly
from the journal publisher) but destined to be
MEDLINE citations.
 A relatively small number of records that are
included in PubMed but not selected for MEDLINE.

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What is MEDLINE?
 The world’s largest biomedical database
 MEDLINE covers:
 Medicine
 Dentistry
 Veterinary Science
 Nursing
 Other Biological Sciences

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What is MEDLINE?
 4,800 journals are indexed
 Covers all aspects of biosciences and
healthcare
 Database of 14+ million journal citations

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What is MEDLINE?
 Covers 1966 to the present
 Coverage worldwide, 85% are in English
 76% have abstracts

28. MEDLINE
 MEDLINE is NLM's bibliographic
database of citations and abstracts,
currently
 > 5,600 biomedical journals
All citations in MEDLINE are
assigned

29. MEDLINE Citations
 PubMed provides access to MEDLINE
 Scope of MEDLINE includes such diverse topics
as microbiology, delivery of health care, nutrition,
pharmacology and environmental health. The
categories covered in MEDLINE include
everything from anatomy, organisms, diseases,
psychiatry, and psychology to the physical
sciences.
 contains over 17 million references dating back to
1948.
 New material is added Tuesday through Saturday.

32. MeSH
 National Library of Medicine's
controlled vocabulary thesaurus.
 consists of sets of terms naming
descriptors in a hierarchical structure
that permits searching at various
levels of specificity.

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What is MeSH?
 MeSH – Medical Subject Headings
 Controlled vocabulary terms
○ Brain Edema, Otitis Media, Myocardial Infarction

34. Practice Exercises
Introduction to
MeSH

35. 1.If you search the term
“phytotherapy” in PubMed,
what terms are you also
searching?

36. ANSWER
1. If you search the term
“phytotherapy” in PubMed, what terms
are you also searching?
 Aromatherapy and
Eclecticism

37. 2.How far back can you
search with the MeSH term,
“Proteomics?”

38. ANSWER
2. How far back can you search with
the MeSH term, “Proteomics?”
 To 2003. For 2000-2002, use
Proteome.

39.  3. What ages are included
by the term, “Child?”

40. ANSWER
3. What ages are included by
the term, “Child?”
 6 to 12 years.

41. 4. What is the preferred
MeSH term for “chewing?”

42. ANSWER
4. What is the preferred MeSH term
for “chewing?”
 Mastication.

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How do I access PubMed?
 Directly at: http://pubmed.gov
 Or, National Library of Medicine’s homepage:
http://www.nlm.nih.gov

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PubMed Screen Layout
Feature Tabs
Query Box aka
Search Box
Blue
Sidebar

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PubMed.gov
 Translates lay terms into medical subject
headings
 Heart Attack into Myocardial Infarction
 Links to selected free articles through
publishers’ web sites
 Most articles are written for health
professionals

47. BOOLEAN

48. Boolean Strategies
- If you are retrieving too many records on
your topic, try adding another search term
with the connector AND.

49. Boolean Strategies
If you are retrieving too few records on
your topic, try adding another search term
with the connector OR.

50. Boolean Strategies
If you are retrieving too many records on an
unrelated topic, try eliminating a word with the
connector NOT.

53. Truncation & Wildcards
 To increase the number of hits retrieved, you might
consider using a truncation symbol. Truncation will
pick up variations of a word stem. Truncation
symbols vary, depending on the database.
 e.g., critic* will find critic, critics, criticism, critical,
etc.
 The wildcard symbol can be used to replace one
letter in a word. This will instruct the computer to do
a search and match all letters in the word and use
any letter to replace the wildcard symbol.
 e.g., Wom?n will retrieve records with woman and
women.

54. Basic Searching
Quotation Marks
“ “
Requires words to searched as a phrase, in the exact order you
type them.
Common Words
Usually Ignored + or “ ”
to search them
Search which versus that.
Only versus is searched on. Which and that are ignored.
To require common words to be searched:
+which versus +that ”which versus that”
Excluding
-word -“phrase in
quotes”
“acute pancreatitis” diet –cat –dog –“pancreatic cancer”

55. Basic Searching
OR allows more than one term
allows pages with at least one of
the terms
OR requires at least one of the terms joined by it to
appear somewhere in the document, in any order.
“abdominal pain” OR blacks ear OR nose OR
throat
The more words you enter connected by OR, the
more documents you get. Broadens the search..
USES:
o The OR operator is generally used to join similar,
equivalent, or
synonymous concepts.
"global warming" OR "greenhouse effect"
Abdomen Pain

56. Basic Searching
AND (default)
is the small overlap where both
terms occur
AND is the default and only needs to be typed if you
are using other Boolean operators with ( ).
Ex.
infopeople training is logically the same as
infopeople and training
The more words you enter connected by AND, the
fewer documents you get. All your words will be
searched on
USES:
o The AND operator is generally used to join
different kinds of
concepts, different aspects of the question.
o "global warming" AND "sea level rise" AND
california
Abdomen Pain

57. Basic Searching
AND NOT
excludes pages that mention
PAIN, even if they also mention
ABDOMINAL
Excludes documents containing whatever follows it.
The AND NOT operator is generally used after you
have performed a search, looked at the results, and
determined that you do not want to see pages
containing some word or phrase.
USES:
• The AND NOT operator should be used with
extreme caution, because it eliminates the entire
page, and some pages may be of value to you
for other information they contain. I almost never
use and not for this reason.
o "global warming" AND "sea level rise" AND
NOT california - The first two terms must be
somewhere and any page containing california will
be thrown out.
Abdomen Pain

58. Basic Searching
NEAR
dogs NEAR cats
requires both terms,
like AND, with the
added requirement
that they be within 16
words of each other
Requires the term following it to occur within a
certain proximity of the preceding word in the
search. In Exalead.com, NEAR requires the terms
to be within 16 words of each other in either
direction.
Joining words by NEAR gives you fewer documents
than AND, because it requires the words to be
closer together.
USES:
o The NEAR operator is used when you want to
require that certain terms appear in the same
sentence or paragraph of the document. o "global
warming" NEAR "sea level rise" - Requires the
two phrases to occur within 16 words of each other,
in either direction.

59. Basic Searching
( )
parentheses:
"Nesting"
Require the terms and operations that occur
inside them to be searched first. This is called
"nesting."
Parentheses MUST BE USED to group terms joined
by OR when there is any other Boolean operator in
the search.
o "global warming" AND "sea level rise" AND
(california OR "pacific coast*") - Requires first
two terms somewhere in all documents, and either
california or pacific coast.
• Parentheses also MUST BE USED with NEAR:
o ("global warming" NEAR "sea level rise") AND
(california OR "pacific coast*") - Requires sea
level rise to be within 16 words of global warming;
the rest can be anywhere in the pages. The
parentheses guarantee that the effect of near stops
with sea level rise.

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Searching PubMed
 Let us use this search:
“I was exposed to asbestos for years in
school. Can that cause gastrointestinal
cancer?”

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Entering Your Search Terms
 Enter terms: asbestos gastrointestinal cancer

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How Does PubMed Interpret What You
Type in the Box?
 PubMed uses Automatic Term Mapping
and maps to:
 Medical Subject Headings – medical terms
 Phrases
 Author Name – lastname initial(s), e.g., smith j,
smith ja
 Journal Titles – full journal title, MEDLINE
abbreviation, ISSN
How do you think PubMed searched your terms?

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The Details tab
The Details tab

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When to Limit?
 There are many reasons for refining a
search strategy. You may want to:
 Exclude foreign language titles
 Look for articles published within a certain
timeframe
 Retrieve articles that focus on women or
perhaps just children

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A quick glance at the results….
Square brackets

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The Limits tab
Limits
tab

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Working with Results
 Citations display in batches of 20 with
most recent additions on top.
 Use the check boxes to select multiple
citations to view
 Click on icons for more information,
such as the abstract

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A Closer Look at Starting a Search
Enter search terms here
and then click on Go.
Add Limits like date, language,
publication type, and more.

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Related Articles
Related Articles

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Links to LinkOut
LinkOut

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The Clipboard tab
 Lets you keep track of the good ones while
you are still searching
 How to:
 #1: Check the citations to keep
 #2: Use the Send pull-down menu to select
Clipboard
 #3:Click on Send.
 Will keep up to 500 records for 8 hours!

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Are there other
ways to limit your search?
 Add additional terms to query box
 copd air pollution
 Use Boolean Connectors
 AND, OR, NOT

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Combination Searching
 Let us use the search:
“I am looking for an article from a few years
ago (maybe 4-5 years ago) by Dr. Keys
about cervical cancer treatment.
It was published in the New England
Journal of Medicine.”

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Combination Searching
 PubMed uses Automatic Term Mapping
and maps the search terms as:
 keys  keys[All Fields]
 cervical cancer  "cervix neoplasms" [MeSH
Terms]
 new england journal of medicine  "N Engl J
Med"[Journal]

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Advanced Searching
 Let us use this search:
“My neighbor had a stroke.
I understand that Dr. Chin has done
research on the neurological aspects
of this and it was published in the
journal Neurology.”

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Preview/Index tab
 Preview the number of search results
before displaying the citations
 Refine searches by adding one or more
terms one at a time
 Add terms to a strategy from specific
search fields

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Preview/Index tab

79. To Know:
Value of research
What to search
How to search

80. Doing Literature
Search