TOSAR – A Topological Method for the Representation of Synthetic and Analytical Relations of Concepts

In mechanized systems used for searching in literature stores there is a steadily growing necessity not only to be able to formulate concepts as a search condition but also the characteristic connections under which these concepts appear in the inquiry. In this way the precision of the mechanized literature search is considerably increased. TOSAR has been developed in order to improve computerized literature searching in this respect.     

Versatile Computer Techniques for Searching by Structural Formulas,Partial Structures,and Classes of Compounds

The principles of the topological encoding of formulas and machine searching are briefly described. These methods have been developed to the point where it is now possible to carry out a computer search for a given structural fragment without the risk of false drops. It is also possible to carry out searches whose requirements, while well-defined and readily used by chemists, cannot be represented exclusively by element symbols and chemical bonds.     

A System for the Documentation of Chemical Reactions

The Documentation Ring of the chemical and pharmaceutical industries uses a punched card system to record chemical reactions. The starting materials and the end products are encoded with a fragmentation code, and the bonds that change during the reaction are recorded in the same way. Reaction modifiers and physical data can also be stored. In the case of multistage reactions, both the individual stages and various groups of stages are recorded.     

A Topological Approach to the Problem of Ring Structures

In the mechanized documentation of chemical literature, the definition of structural concept is very important. The usual for definitions for ring structures are inadequate. Essential ring structures are sometimes not recognized on the basis of these definitions and are therefore missed in a literature search. This is particularly true of bridged ring systems. The ring concept and ring condensation types are now redefined on a topological basis in the closest possible analogy to the intuitive approach of the chemist. In complicated molecular structures, these “fundamental rings” can be easily determined, either manually or by means of a programmed computer. The concept of the “ring complex” is defined and suggested as a preliminary screen in literature searches for ring structures. This will save machine time, and so reduce the cost of searches.     

Chemical information services

The definition of information services derives from the demarcation between documentation and information. The main criteria for information services are up-to-dateness, clarity, manageability, relevance, and flexibility. In addition to the printed information media (tables of contents, lists of titles, abstract journals) services have been offered in recent years which are prepared with the aid of data processing machines and which operate on the basis of data tapes (SDI, profile searches).     

Natural versus Indexing Language in Chemical Documentation

In any literature searh one must be able to predict which modes of expression have been used to represent the concepts of interest in the search file. It is these lingual expressions which will be looked up or will constitute the search parameters in a mechanized search. In the case of general concepts and statements, uncontrolled natural language lacks the required representational predictability, as is demonstrated, for example, for classes of chemical compounds and for types of reactions. Hence, considerable loss of relevant information is bound to occur in searches for these concepts in free text files, regardless of how advanced a computer program may be. By restricting the modes of expression as is achieved by means of an indexing language and its reliable employment, predicability is increased and, consequently, information loss is drastically reduced.—In contrast, the modes of expression for individual concepts (e.g. individual chemical substances, authors, institutions) are, by their vary nature, often sufficiently predictable in uncontrolled natural language. In these cases, the value of translating them into indexing-language expressions is often questionable. This holds true in particular if an indexing language does not (yet) provide adequate expressions to represent the concepts, and also in the case of ambiguous natural language expressions. Here, preserving the original, uncontrolled terms in the search file is advisable, at least in addition to an attempted translation into the indexing language.—The weaknesses of uncontrolled natural language files become apparent only at a rather late stage in the continual expansion of an information system. In its early stages the necessity of predictability is reduced through the effectiveness of human memory and the—initially—relatively high homogeneity of the experts' linguistic usage during that short period of time. Furthermore, loss of relevant information as a consequence of the lack of predictability will at first be minimal and will not yet be noticed as a steadily increasing source of search failure. Nor does the steady rise in costs for excogitating and phrasing queries with more and more alternatives become apparent at this stage. It is largely for these reasons that uncontrolled natural language systems have unjustifiably frequently been preferred. The typical weakness and strengths of both kinds of language suggest combining them so that their inherent strengths are retained and utilized as far as possible.     

Possibilities and limitations of delegated literature searches by computer

The present-day chemist is constantly on the lookout for information which may be useful to his work. If he is able to define his interests precisely enough then he can avail himself of information scientists and of specialized literature stores. However, retaining access to such information, which only he himself can subjectively judge for relevance to his work, and which most often constitutes a powerful incentive to his creative thinking, will always require his own “browsing” literature studies or personal contacts. These are the limitations of any delegated literature search.     

Quantitative color analysis of laryngeal erythemain chronic posterior laryngitis

The purpose of this study was to quantitatively analyze the degree of erythema visible in the larynges of normal subjects and of patients with symptoms of chronic posterior laryngitis. Video-documented examinations of laryngoscopy were digitized and then analyzed using computer image analysis software that allowed quantification of average color values, hue, saturation, and brightness from digitized color images. Documented laryngoscopic images from 7 normal subjects and 64 patients complaining of chronic laryngitis symptoms were examined, and additional patient examinations which were obtained and documented during treatment for reflux laryngitis were analyzed. Analysis was made of five different areas of each laryngeal image: the right and left vocal folds, the right and left vocal processes, and the posterior arytenoid mucosa. Data analysis showed that average color value ratings of redness for the patients with chronic laryngitis were significantly (p <0 .0561) greater than the average values for normal subjects for the vocal folds. Color values for redness of the posterior laryngeal structures and vocal folds in the patients who were treated for reflux laryngitis were significantly (p < 0.05) reduced over time and correlated with the clinical response to treatment. The data suggest that computer color analysis of documented video-laryngoscopy examinations can provide quantitative data on degree of erythema and may be useful as a quantitative means of diagnosis and documentation of treatment outcome for reflux laryngitis.