Information retrieval searches

A good nomenclature scheme should accomplish two tasks (1) accurately name all of the existing known compositions and (2) provide a present and future base for making systematic information retrieval searches for known, missing, unsynthesized, or unrecognized materials included within the nomenclature scheme. 

Citation Searching. In the scholarly Hterature, authors cite earHer pubHcations that relate to the work being reported, thus a subject relationship exists between the citing and cited Hterature. This relationship has formed the basis for the Science Citation Index and related products, developed by the Institute for Scientific Information. Known as Scisearch in its on-line version, the Science Citation Index has become an important information retrieval tool in the second half of the twentieth century. It has been used for straightforward subject searching, in which mode it complements traditional indexed databases and indexes. It has also become a popular tool for hihliometric studies of various sorts, such as attempts to measure the relative impact of research carried out by different individuals or organizations, or the relative impact of pubHcations in different journals. 

Provides access to textual and numeric data in its databases for information retrieval and reporting needs. Features word proximity and phrase searching thesaurus and index. 

The current version of eChemPortal offers the possibility to retrieve information by searching on chemical names or CAS Registry numbers. The second phase will incorporate additional search options to retrieve and compile specific hazard or other effects data (e.g., toxicity endpoints) from the participating databases. 

Validity describes accuracy and reflects the soundness of the information. The information retrieved is valid if it is accurate, precise, unbiased, and provides a true picture of what is in the literature. The usefulness of the information is directly related to relevance and validity and inversely related to the work needed to access the information. While the work expended is under the direct control of the searcher, it is not unlimited. Therefore, given the limited amount of work time that is available to the information searcher, the most useful information resources will be those that are easy and quick to use and provide relevant, valid information. Skillful searchers can control work time, but relevance and validity are intrinsic characteristics of the resources themselves. A knowledgeable searcher will not only choose resources that are known to be relevant and valid, but will also use search techniques and filters that winnow out the irrelevant and invalid. 

Chemithon film sulfonating-sulfating systems, 23 544-547 Chemithon reactor, 23 544 Chemoinformatics, 6 1-25 chemical databases, 6 19-20 chemical information retrieval, 6 6—19 chemical information storage, 6 2-6 chemical library design, 6 17-18 clustering techniques, 6 16-17 conformational flexibility, 6 10-11 conformational searches, 6 10-11 data analysis and preparation, 6 20-21 data searching, 6 6-19 diversity searches, 6 14-18... 

As mentioned earlier, chemical composition and identification information should already have been obtained before the chemical is to be searched. With most information retrieval systems this is a relatively straightforward procedure. Citations on a given subject may be retrieved by entering the desired free text terms as they... 

In what follows, we shall adopt ideas and terminology from that part of computer science that is normally referred to as information retrieval (8-10). The measurement of search effectiveness has played a large part in the development of information retrieval (or IR) systems, whose principal aim is to identify as many documents as possible that are relevant to a user s query while simulta-... 

MAECIS contains five major sections that are integrated into a single system. At its center is a database management system that handles the storage and updating of data and chemical structures. Associated with this section is an information retrieval section that allows one to search the database for specific information composed of any combination of data and/or substructures. Once information is retrieved, it can be displayed on a computer terminal or sent to a printer for hardcopy output using the display section of MAECIS which includes the ability to display chemical structures in various formats. The final two sections of MAECIS allow for the manipulation of chemical structures and the calculation of various molecular properties that are related to chemical structures. 

The information retrieval in MAECIS is accomplished using one of three available commands SHOW, FIND, or SEARCH. The SHOW command is the simplest one to use and requires only a code number or registry number. It allows the user to retrieve all chemical structures and associated information stored under a particular code number. In most cases this fulfills the user s needs. The FIND command is used for complex searches involving various combinations of multiple data fields, handles substructure searching. Queries such structures with a molecular weight between 200 and 250 containing an ester substructure" are handled by the FIND command. Finally, the SEARCH command is used for chemical structure searches. This search takes only seconds and allows the chemist to determine if a particular molecule is already in the database. 

Other variations of Memory subsystem functioning occur in various d ASCs. The ease with which desired information can be retrieved from memory varies so that in some d-ASCs it seems hard to remember what you want, in others it seems easier than usual. The richness of the information retrieved varies in different d-ASCs, so that sometimes you remember only sketchily, and at other times in great detail. The search pattern for retrieving memories also varies. If you have to go through a fairly complex research procedure to find a particular memory, you may end up with the wrong memories or associated memories rather than what you were looking for. if you want to remember an old friend s name, for example, you may fail to recall the name but remember his bi rthday. 

PubChem is organized as three linked databases within the NC8I s Entrez information retrieval system. These are PubChem Substance. PubChem Compound, and PubChem BioAssay. Pubchem also provides a fast chemical structure similarity search tool. More information about using each component database may be found using the links above. 

The basic ILLINET Online Network (Illinois Online Network) was used as the major computer-assisted information retrieval program. Within this network IBIS (Illinois Bibliographic Information Service), which provides abstracts taken from journal articles published from 1991 through December 1993, and CARL UnCover (Colorado Alliance of Research Libraries), which provides titles to journal articles published in 1988 through December 1993, afforded much of the current and recent information reported on here. Abstracts of the pertinent literature published from 1982 through mid-1993 were also obtained directly from CA (Chemical Abstracts). It is hoped that the overlap provided this way assures the broadest retrieval of published results. All of these sources were searched by means of the following key words ... 

Information retrieval From statistical analysis of full text indices to semantic search based on entity classes defined by NER... 

Information-retrieval systems engineered to serve the various levels of literature searching may be drastically different from one another. Appraisal of the potential information-retrieval requirements of the foreseeable future may be a critical consideration in engineering a new system. 

KENT AND GEER Mechanical Searching for Information Retrieval... 

The first stage in practicing EBM is to define the precise question to which an evidence-based answer is required. A carefully focused question will inform the search for relevant evidence, and should (hopefully) avoid excessive retrieval of irrelevant publications and other information sources. For example, a clinician who wishes to know whether it is best to use oral or topical antifungals for the treatment of vaginal candidiasis could articulate the question as What is the relative effectiveness of oral versus intra-vaginal antifungals for the treatment of uncomplicated vulvovaginal candidiasis ... 

---