Databases strategies

The initial step is to identify which database, from a few thousands worldwide (about 10 000 in 2002), provides the requested information. The next step is to determine which subsection of the topic is of interest, and to identify typical search terms or keywords (synonyms, homonyms, different languages, or abbreviations) (Table 5-1). During the search in a database, this strategy is then executed (money is charged for spending time on some chemical databases). The resulting hits may be further refined by combining keywords or database fields, respectively, with Boolean operators (Table 5-2). The final results should be saved in electronic or printed form. 

Structure databases are databases that contain information on chemical structures and compounds. The compounds or structure diagrams are not stored as graphics but are represented as connection tables (see Section 2.4). The information about the structure includes the topological arrangement of atoms and the connection between these atoms. This strategy of storage is different from text files and allows one to search chemical structures in several ways. 

Besides structure and substructure searches, Gmclin provides a special search strategy for coordiuation compouuds which is found in no other database the ligand search system, This superior search method gives access to coordination compounds from a completely different point of view it is possible to retrieve all coordination compounds with the same ligand environment, independently of the central atom or the empirical formula of the compound. 

Most databases, e.g. the World Patents Index, provide a "Learn database" function (LWPl) to give the opportunity for training in the specific retrieval strategies for patents. 

It can be said that these three main strategies have been applied equally and very often in combination. Basically, the first approach implies the use of a faster computer or a parallel architecture. To some extent it sounds like a brute force approach but the exponential increase of the computer power observed since 1970 has made the hardware solution one of the most popular approaches. The Chemical Abstracts Service (CAS) [10] was among first to use the hardware solution by distributing the CAS database onto several machines. 

Subject-Based Retrieval Parameters. There are numerous means by which the subject content of a patent can be expressed, and which a searcher can use in developing a search strategy. Different databases offer differing subsets of these means. Effective strategies should in general not be limited to a single type of retrieval parameter rather, they should be built from different parameters and modified as needed to provide the strategy best fitted to the subject at hand. 

Patent classification codes are another subject-search parameter available in most patent databases. IPC codes are usually present and U.S. codes exist in a number of files in the case of Japan Patent Information Organization (JAPIO), Japanese codes too are available. It is possible to mimic a hand search by limiting operations to references falling within one class or group of classes. Although such strategies can in some instances be justified, it is usually wiser to treat class codes as just one of the various subject parameters that make up a search strategy. 

Databases differ in their strengths and weaknesses, as well as in their focus. As a result, dupHcate searches carried out on different databases generally produce different results. This has been demonstrated in comparative studies of retrieval results for a group of patent databases (31,32). Participants in one study (31) made an effort to develop optimal search strategies in each database tested, yet in no instance did one file produce perfect retrieval. Both investigations (31,32) found that results from the various databases complemented each other. As a result, searchers are counseled to use multiple databases whenever possible. There is no pat answer to the question of how many files to use or which files to use however, more files mean more expenditure, and searchers must develop their own cost—benefit relationship. 

Electronic marketplace/E-commerce In addition to the many databases available and person-to-person contacts, E-commerce in plastics has been conducted through suppliers web sites or the dot-commerce independent web sites that link material buyers with sellers in transactions or auction formats. During the year 2000 five plastic producers/suppliers and various elastomer producers/suppliers created a new and important business model of a joint-venture web site. It provides multiple companies to join forces to do business. This is a strategy some observers call competition and others regard as just another form of selling in. an electronic format. Regardless of how it is perceived, the model will help propel e-commerce into the mainstream of processor procurement due to the size and wealth of the companies involved. The plastic model example is the largest online business-to-business site todate. 

Ewing TJ, Makino S, Skillman AG, Kuntz ID. DOCK 4.0 search strategies for automated molecular docking of flexible molecule databases. J Comput Aided Mol Dei 2001 15 411-28. 

Hybrid systems are those systems that employ various strategies to collect data. In such systems, data may be collected on paper forms as patient self-administered questionnaires, while additional data may be downloaded from centralized databases. 

These DNA markers have been successfully employed to track specific strain-associated loci in endo- and ectomycorrhizal populations from agricultural land, forest nurseries, plantations, and natural ecosystems. The simplest strategy (digesting PCR-amplified ITS with selected endonucleases) has identified their symbionts in various ecosystems (18,36-38). Species discrimination by ITS-RFLP matching can be improved by comparing data for the targeted DNA with those on sequence databases (37). 

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