ChEBI: a database and ontology for chemical entities of biological interest.

Chemical Entities of Biological Interest (ChEBI) is a freely available dictionary of molecular entities focused on 'small' chemical compounds. The molecular entities in question are either natural products or synthetic products used to intervene in the processes of living organisms. Genome-encoded macromolecules (nucleic acids, proteins and peptides derived from proteins by cleavage) are not as a rule included in ChEBI. In addition to molecular entities, ChEBI contains groups (parts of molecular entities) and classes of entities. ChEBI includes an ontological classification, whereby the relationships between molecular entities or classes of entities and their parents and/or children are specified. ChEBI is available online at http://www.ebi.ac.uk/chebi/

The Camden Schizophrenia Surveys. III: Five-year outcome of a sample of individuals from a prevalence survey and the importance of social relationships.

BACKGROUND: Most studies of outcome in schizophrenia have focused on incidence cohorts or samples identified through specialist mental health services; population-based samples provide a more complete picture of the effectiveness of community services. AIMS: To examine whether outcome predictors, derived from studies of selected patients with prolonged schizophrenia, would emerge in a largely community-dwelling population sample. METHODS: A follow-up sample of 114 adults with schizophrenia was identified via two censuses of key informants conducted for two prevalence surveys in North London, five years apart. Symptomatic, clinical and functional outcomes were assessed after five years. A composite score was derived for each individual. Multiple Linear Regression analyses were conducted in two phases to derive a best subset of predictors for global outcome. RESULTS: After five years, 33% were worse and 62% were better overall. The four best predictors (social isolation, living apart from relatives, longer illness and being an inpatient at first census) accounted for 32% of the variance in outcome of those with schizophrenia and related diagnoses. CONCLUSIONS: Social relationships during the course of illness are an important predictor of overall outcome and relationships with friends and family each seem to make a positive contribution. Policy and service developments should focus on improving participation in community life for people with schizophrenia, particularly their social connectedness.

InChI, the IUPAC International Chemical Identifier.

This paper documents the design, layout and algorithms of the IUPAC International Chemical Identifier, InChI.

InChI - the worldwide chemical structure identifier standard.

Since its public introduction in 2005 the IUPAC InChI chemical structure identifier standard has become the international, worldwide standard for defined chemical structures. This article will describe the extensive use and dissemination of the InChI and InChIKey structure representations by and for the world-wide chemistry community, the chemical information community, and major publishers and disseminators of chemical and related scientific offerings in manuscripts and databases.

InChIKey collision resistance: an experimental testing.

InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be a nearly unique substitute for the parent InChI. However, a single InChIKey may occasionally map to two or more InChI strings (collision). The appearance of collision itself does not compromise the signature as collision-free hashing is impossible; the only viable approach is to set and keep a reasonable level of collision resistance which is sufficient for typical applications.We tested, in computational experiments, how well the real-life InChIKey collision resistance corresponds to the theoretical estimates expected by design. For this purpose, we analyzed the statistical characteristics of InChIKey for datasets of variable size in comparison to the theoretical statistical frequencies. For the relatively short second block, an exhaustive direct testing was performed. We computed and compared to theory the numbers of collisions for the stereoisomers of Spongistatin I (using the whole set of 67,108,864 isomers and its subsets). For the longer first block, we generated, using custom-made software, InChIKeys for more than 3 × 1010 chemical structures. The statistical behavior of this block was tested by comparison of experimental and theoretical frequencies for the various four-letter sequences which may appear in the first block body.From the results of our computational experiments we conclude that the observed characteristics of InChIKey collision resistance are in good agreement with theoretical expectations.