Chemical Information Retrieval 1. The ScienceDirect Online Database

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1 Chemical Information Retrieval The ScienceDirect Online Database ScienceDirect is a research database that offers access to over 1500 journals covering all fields of science. On the Library home page, select Find Materials and then Research Databases... Click on ScienceDirect in the Frequently Used section in the lower right corner of the screen. NOTE: You also can go directly, so to speak, to the ScienceDirect website from this URL: Searching for Information about Chemistry When you have reached the Science Direct web site, click on Search. Chemical Information Retrieval 1

2 Click on Advanced search on the right side of the screen. Then click on Expert search. On the Expert Search screen select Chemistry as the Subject. I generally look in All Sources for the information. You also can specify a range of dates within which to search if you should so desire. I usually choose All years unless I have a reason to narrow the search by date -- for instance if you wanted only recent articles. Chemical Information Retrieval 2

3 Boolean and Proximity Operators Expert searching allows you to use Boolean and Proximity Operators to conduct complex searches. The Boolean and Proximity operators available in ScienceDirect are outlined below. OR Searches for documents that contain either word1 or word2. AND Searches for documents that contain both word1 and word2. This is more restrictive than OR. AND NOT Searches for documents that do not contain a word. W/n Searches for documents that contain both word1 and word2 near each other within n words in either direction. This is more restrictive than AND. PRE/n Searches for documents in which word1 precedes word2 by n words. The PRE/n operator is more restrictive than the W/n operator. Truncating Words with Wildcard Symbols In ScienceDirect, you can use the wildcard symbols * and? to truncate words. Use an asterisk (*) to replace zero or more characters in a search word. For example, pigment* will match pigment, pigments, and pigmentation. Use a question mark (?) to replace exactly one character in a search word. For example, Wom?n would match woman and women. Transplant?? would match transplanted, but not transplantation. Using Parentheses In complicated queries, the order in which you want the Boolean operators to work may not be obvious. In this case it is best to group terms with parentheses to ensure that you obtain the desired search. Consider the following two queries: (kidneys OR renal) AND disease This query will find articles about diseases involving either the kidneys or the renal system. It will only find articles that deal with diseases that involve the kidneys, the renal system or both. It will not find articles about heart disease. It will not find recipes for dishes made from kidneys. kidneys OR (renal AND disease) This query will find articles about kidneys, renal diseases, or both. It will find articles that deal with diseases of the renal system. It will find recipes for dishes made from kidneys. It will not find articles about heart disease. Chemical Information Retrieval 3

4 Preparing for an Online Search Search Example: Suppose you are chemist interested in semiconductors. You have been told that carbon nanotubes, small tubes of carbon atoms related to buckyballs, become semiconductors when small amounts of boron are added to the carbon during the formation of the nanotubes (called "boron doping"). You would like to find literature references on this subject. Three concepts are associated with this search: semiconductor nanotube boron doping In 2012, this search query found 168 articles, which is quite a few. Still, considering the importance of the topic, we might consider broadening our search. Broadening a Search If a search query does not produce many results, consider using wildcard symbols to increase the number of articles you find. For our specific case, we might try the following search terms. semiconduct* to look for semiconductor, semiconductivity, and semiconducting nanotube* to look for nanotube and nanotubes dop* to look for dope, doped, and doping As would be expected, this finds more articles 1,779 in You can sort the articles by relevance or by date. Click on Preview under some of the titles to see an abstract of the article. Chemical Information Retrieval 4

5 You may notice that a graphical abstract is displayed for some of the articles. If you see a small green icon to the left of the article, a full-text version is available. Click on PDF, which will display the article as a PDF document that you can print out. Looking at Related Articles You can broaden a search by looking at other articles that Science Direct identifies as being related to ones you have found. Click on Related articles under one of the articles you have found to see how many there are. This sometimes broadens the search more than you might want in the example at the right 656 articles are found. It is worth checking, though. Chemical Information Retrieval 5

6 Narrowing a Search Science Direct allows you to narrow a search by limiting it to a particular journal type or year. For example, you may have found a lot of good material in the journal Chemical Physics Letters in the past, and would only like to see articles from this journal. Click on the checkbox to the left of this journal and then click on Limit To. You now will see only articles from this particular journal displayed. Note that you also can exclude a particular journal or year. Chemical Information Retrieval 6

7 Why Search Individual Databases You may wonder why we are searching in an individual database, such as Science Direct, if Wofford OneSearch searches all the Library databases. OneSearch is designed to give a relevant but not a complete set of search results. It does search all the Library databases and then returns a result set based on the databases it considers to be most relevant. A search in an individual database always is going to be more specific than a OneSearch search, though. Here is an example. I used the query below in both OneSearch and Science Direct semiconduct* AND nanotube AND (boron or B) AND dop* Wofford OneSearch: 881 results Science Direct: 8276 results The search in the individual database returns many more results, and different ones as well if you compare the two result lists. It appears to me that OneSearch is a little like Google a really good starting place for a search, but not the only one you should do. After you have used OneSearch to help you get ideas about terms to include in a search query and have saved the relevant search results you have found, it always is a good idea to move to the more specialized and specific individual databases. Search Problem You are interested in finding information on the molecular level about the activity of marijuana (cannabis, cannabinoids, etc.). You don't want to find information about the legalization of marijuana. Make such a search in ScienceDirect. Limit the search to journal articles Look only for articles published in the past five years. Include only these two subjects: Chemistry and Biochemistry, Genetics, and Molecular Biology. Formulate a search query for this subject. After you have formulated your query, you might look at the next page where I have posted a suggested initial query. Chemical Information Retrieval 7

8 Suggested Search Query activ* AND (marijuana OR cannab*) AND NOT legaliz* Chemical Information Retrieval 8