Data computerized searching

In searching for data on a particular system, a computerized search of Chemical Ah.stract.s, Tngineering Index, and National Technical Information Service (NTIS) data bases should seriously be considered. Although the NTIS computer contains only information published after 1970, one normally can assume that most pre-1970 pubhcations of merit hkely will be referenced in the bibhographies of current articles on the subject. 

A system, shown in Table I, has been devised consisting of nine categories, each with a number of keywords for a computerized search for multiple identical features from a data bank of international FFB literature. The so-called categories are represented by digit numbers ... 

Syndromic surveillance systems have developed in tandem with advances in information technology. A major component of many syndromic systems is the use of available electronic databases to capture health indicator data. With such computerized data, automated search algorithms can he applied to detect unusual patterns that may signal an outbreak and can provide that signal earlier than is feasible using traditional surveillance methods (CDC, 2000 Lazarus et al., 2002 Polyak, Elbert, Pavlin, Kelley, 2002 Teich et al., 2002). 

Chain transfer to the aluminium alkyl was also deserved. Using the method of moments the authors obtained an equation for the first three moments of active, temporarily deactivated, and dead chains. As a result of a computerized search for the values of constants, based on the model and on the experimental data obtained in a batch reactor (volume = 131), some of the values were found to differ considerably from those published in the literature. 

These are very simple examples, but provide a plan of attack for the problems at the end of the chapter. It is highly unlikely that an analyst can identify a complete unknown by its IR spectrum alone (especially without the help of a spectral library database and computerized search). For most molecules, not only the molecular weight, but also the elemental composition (empirical formula) from combustion analysis and other classical analysis methods, the mass spectrum, proton and C NMR spectra, possibly heteroatom NMR spectra (P, Si, and F), the UV spectrum, and other pieces of information may be required for identification. From this data and calculations such as the unsaturation index, likely possible structures can be worked out. 

Latter et al have recently published the results of a study in which cells growing in culture were labelled with 20 radioactive amino acids, each in a different experiment, and analyzed by 2D6EL (S4). The resulting autoradiographs were studied with an image analysis system so that amino acid compositional data could be extracted. This information was then compared to the amino acid composition data resident in two large data bases, using computerized search methods. Out of the 122 spots studied in this manner, tentative identifications could be made on 17 of them based on the amino acid composition alone. 

The methods discussed for searching the literature use mainly printed materials. Modern search methods also make use of computerized databases and are discussed in Section 29.11. These are vast collections of data and bibliographic materials that can be scanned rapidly from remote computer terminals. Although computerized searching is widely available, it may not be readily accessible to undergraduate students. The following references provide excellent introductions to the literature of organic chemistry ... 

In recent years, computer automation has greatly reduced the amount of work required for x-ray analysis of structure and composition so that much of the data analysis is now commonly performed by software and computerized search programs. Structural analysis involves the measurement of the lattice parameters of the crystal (the unit cell dimensions) and the structural model of the crystal (the crystal structure). While the use of single crystals is the preferred... 

The literature survey pertaining to this chapter covers publications from 1975 to 2001, based on computerized search. CD data before 1975 have been compiled by Yang et al. [76Y2] elsewhere. With a voluminous amount of publications, it is unavoidable that some interesting CD data might have been overlooked. 

Since published CD data of proteins are usually concentrated in the far-UV region, Table IV presents the intensities of CD at extrema for data below 250 nm, which constitute the major part of this chapter. Usually the earliest values are listed and occasionally additional references are given when there are serious discrepancies among different laboratories. Most numerical values were read from the published CD figures. Thus, usually only one or two significant figures are listed for the mean residue ellipticities unless the authors have provided the numerical values. The positions of the CD extrema can also vary by 1 or 2 nm. The objective of the table is not to compile a complete set of available CD data of proteins but to familiarize the reader with the source of the selected proteins. With the aid of computerized search or other means, the reader can use the table as a quick starting point for a literature survey. 

With the availability of computerized data acquisition and storage it is possible to build database libraries of standard reference spectra. When a spectrum of an unknown compound is obtained, its identity can often be determined by searching through a library of reference spectra. This process is known as spectral searching. Comparisons are made by an algorithm that calculates the cumulative difference between the absorbances of the sample and reference spectra. For example, one simple algorithm uses the following equation... 

Offers direct access to virtually all of the world s scientific and data bases for toxicology and related information. Covers chemicals, pesticides, food additives, industrial chemicals, heavy metals, environmental pollutants, and pharmaceuticals. The Center is online to more than 400 computerized databases, including DIALOG, MEDLARS, STN International, ITIS, and DROLS. It performs searches for outside users for a fee. 

Today, analytical evaluation is done on a large scale in a computerized way by means of data bases and expert systems (Sect. 8.3.6). In particular, a library search is a useful tool to identify pure compounds, confirm them and characterize constituents in mixtures. Additionally, unknown new substances may be classified by similarity analysis (Zupan [1986], Hippe [1991], Warr [1993], Hobert [1995]). The library search has its main application in such fields where a large number of components has to be related with large sets of data such as environmental and toxicological analysis (Scott [1995], Pellizarri et al. [1985]). 

Computerized data-base versions of RTECS give the capability of extracting substance lists by "Classification Codes." For example, one might ask the system to search for all compounds with classification Code of TUMORIGEN. How many users will have read the user s guide carefully enough to know that this means only that these compounds may have been reviewed by IARC or NTP but NOT that they have been indicted as tumorigenic ... 

Toxnet (Toxicology Data Network) is a computerized network of toxicologi-cally oriented data banks. Toxnet offers a sophisticated search and retrieval package that accesses the following three subfiles ... 

Computerized Information System. The Project SEARCH Criminalistics Laboratory Information System (CLIS) Committee is another LEAA funded project. Approximately fifteen criminalists are serving on the CLIS Committee which is conducting a requirements analysis for a nationwide computerized crime laboratory information system. With the assistance of a technical subcontractor, PRC Public Management Services, Inc., the committee has determined the "user needs" for such a data system, a conceptual design of a computer system to meet these requirements, and an assessment of different organizational and equipment alternatives for the system. The most recent task reports and implementation plan have been completed and submitted to the advisory committee for final review. Copies of the final reports should be ready for dissemination in the very near future. 

VERIFY is a computerized database designed for the storage, management, and search of chemical and analytical reference data (44). Properties and contents of the NMR part of VERIFY are ... 

The VERIFY is designed to work in the PC environment. The advantages of the computerized version relative to the paper version of the NMR library are easier access to the spectra and data search routines. 

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