237 research outputs found
Foreign Language Translation of Chemical Nomenclature by Computer
Chemical compound names remain the primary method for conveying molecular structures between chemists and researchers. In research articles, patents, chemical catalogues, government legislation, and textbooks, the use of IUPAC and traditional compound names is universal, despite efforts to introduce more machine-friendly representations such as identifiers and line notations. Fortunately, advances in computing power now allow chemical names to be parsed and generated (read and written) with almost the same ease as conventional connection tables. A significant complication, however, is that although the vast majority of chemistry uses English nomenclature, a significant fraction is in other languages. This complicates the task of filing and analyzing chemical patents, purchasing from compound vendors, and text mining research articles or Web pages. We describe some issues with manipulating chemical names in various languages, including British, American, German, Japanese, Chinese, Spanish, Swedish, Polish, and Hungarian, and describe the current state-of-the-art in software tools to simplify the process
Information retrieval and text mining technologies for chemistry
Efficient access to chemical information contained in scientific literature, patents, technical reports, or the web is a pressing need shared by researchers and patent attorneys from different chemical disciplines. Retrieval of important chemical information in most cases starts with finding relevant documents for a particular chemical compound or family. Targeted retrieval of chemical documents is closely connected to the automatic recognition of chemical entities in the text, which commonly involves the extraction of the entire list of chemicals mentioned in a document, including any associated information. In this Review, we provide a comprehensive and in-depth description of fundamental concepts, technical implementations, and current technologies for meeting these information demands. A strong focus is placed on community challenges addressing systems performance, more particularly CHEMDNER and CHEMDNER patents tasks of BioCreative IV and V, respectively. Considering the growing interest in the construction of automatically annotated chemical knowledge bases that integrate chemical information and biological data, cheminformatics approaches for mapping the extracted chemical names into chemical structures and their subsequent annotation together with text mining applications for linking chemistry with biological information are also presented. Finally, future trends and current challenges are highlighted as a roadmap proposal for research in this emerging field.A.V. and M.K. acknowledge funding from the European
Community’s Horizon 2020 Program (project reference:
654021 - OpenMinted). M.K. additionally acknowledges the
Encomienda MINETAD-CNIO as part of the Plan for the
Advancement of Language Technology. O.R. and J.O. thank
the Foundation for Applied Medical Research (FIMA),
University of Navarra (Pamplona, Spain). This work was
partially funded by Consellería
de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia), and FEDER (European Union), and the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic
funding of UID/BIO/04469/2013 unit and COMPETE 2020
(POCI-01-0145-FEDER-006684). We thank Iñigo Garciá -Yoldi
for useful feedback and discussions during the preparation of
the manuscript.info:eu-repo/semantics/publishedVersio
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Extraction of chemical structures and reactions from the literature
The ever increasing quantity of chemical literature necessitates
the creation of automated techniques for extracting relevant information.
This work focuses on two aspects: the conversion of chemical names to
computer readable structure representations and the extraction of chemical
reactions from text.
Chemical names are a common way of communicating chemical structure
information. OPSIN (Open Parser for Systematic IUPAC Nomenclature), an
open source, freely available algorithm for converting chemical names to
structures was developed. OPSIN employs a regular grammar to direct
tokenisation and parsing leading to the generation of an XML parse tree.
Nomenclature operations are applied successively to the tree with many
requiring the manipulation of an in-memory connection table representation
of the structure under construction. Areas of nomenclature supported are
described with attention being drawn to difficulties that may be
encountered in name to structure conversion. Results on sets of generated
names and names extracted from patents are presented. On generated names,
recall of between 96.2% and 99.0% was achieved with a lower bound of 97.9%
on precision with all results either being comparable or superior to the
tested commercial solutions. On the patent names OPSIN s recall was 2-10%
higher than the tested solutions when the patent names were processed as
found in the patents. The uses of OPSIN as a web service and as a tool for
identifying chemical names in text are shown to demonstrate the direct
utility of this algorithm.
A software system for extracting chemical reactions from the text of
chemical patents was developed. The system relies on the output of
ChemicalTagger, a tool for tagging words and identifying phrases of
importance in experimental chemistry text. Improvements to this tool
required to facilitate this task are documented. The structure of chemical
entities are where possible determined using OPSIN in conjunction with a
dictionary of name to structure relationships. Extracted reactions are
atom mapped to confirm that they are chemically consistent. 424,621 atom
mapped reactions were extracted from 65,034 organic chemistry USPTO
patents. On a sample of 100 of these extracted reactions chemical entities
were identified with 96.4% recall and 88.9% precision. Quantities could be
associated with reagents in 98.8% of cases and 64.9% of cases for products
whilst the correct role was assigned to chemical entities in 91.8% of
cases. Qualitatively the system captured the essence of the reaction in
95% of cases. This system is expected to be useful in the creation of
searchable databases of reactions from chemical patents and in
facilitating analysis of the properties of large populations of reactions
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Automatic Analysis and Validation of the Chemical Literature
ThesisMethods to automatically extract and validate data from the chemical literature in legacy formats to machine-understandable forms are examined. The work focuses of three types of data: analytical data reported in articles, computational chemistry output files and crystallographic information files (CIFs). It is shown that machines are capable of reading and extracting analytical data from the current legacy formats with high recall and precision. Regular expressions cannot identify chemical names with high precision or recall but non-deterministic methods perform significantly better. The lack of machine-understandable connection tables in the literature has been identified as the major issue preventing molecule-based data-driven science being performed in the area. The extraction of data from computational chemistry output files using parser-like approaches is shown to be not generally possible although such methods work well for input files. A hierarchical regular expression based approach can parse > 99:9% of the output files correctly although significant human input is required to prepare the templates. CIFs may be parsed with extremely high recall and precision, contain connection tables and the data is of high quality. The comparison of bond lengths calculated by two computational chemistry programs show good agreement in general but structures containing specific moieties cause discrepancies. An initial protocol for the high-throughput geometry optimisation of molecules extracted from the CIFs is presented and the refinement of this protocol is discussed. Differences in bond length between calculated and experimentally determined values from the CIFs of less than 0.03 Angstrom are shown to be expected by random error. The final protocol is used to find high-quality structures from crystallography which can be reused for further science.Unilever Centre for Molecular Science Informatic
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Chemical Information Bulletin
Periodic supplement for "the regular journals of the American Chemical Society," containing annotated bibliographies of chemical documentation literature as well as information about meetings, conferences, awards, scholarships, and other news from the American Chemical Society (ACS) Division of Chemical Literature
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Chemical Information Bulletin
Periodic supplement for "the regular journals of the American Chemical Society," containing annotated bibliographies of chemical documentation literature as well as information about meetings, conferences, awards, scholarships, and other news from the American Chemical Society (ACS) Division of Chemical Literature
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Automated analysis and validation of open chemical data
Methods to automatically extract Open Data from the chemical literature,
validate it, and use it to validate theory are examined.
Chemical identifiers which assist the automatic location of chemical structures
using commercial Web search engines are investigated. The IUPAC
International Chemical Idenfitifer (InChI) gives almost 100% recall and precision,
though is shown to be too long for present search engines. A combination
of InChI and InChIKey, a shorter, fixed-length hash of the InChI
string, is concluded to be the best current method of identifying structures.
The proportion of published, Open Crystallographic Information Files
(CIFs) that are valid with respect to the specification is shown to be improving,
and is around 99% in 2007. The error rate in the conversion of valid
CIFs to Chemical Markup Language (CML) is less than 0.2%. The machine
generation of connection tables from CIFs requires many heuristics, and in
some cases it is impossible to deduce the exact connection table.
CrystalEye, a fully-automated system for the reformulation of the fragmented
crystallographic Web into a structured XML-based repository is described.
Published, Open CIFs can be located and aggregated programmatically
with almost 100% recall. It is shown that, by converting CIF data
to CML, software can be created to use the latest Web standards and technologies
to enhance the ability of Web users to browse, find, keep updated,
download and reuse the latest published crystallography.
A workflow for the high-throughput calculation of solid-state geometry
using a semi-empirical method is described. A wide-range of organic and
inorganic systems provided by CrystalEye are used to test both the data and
the method. Several errors in the method are discovered, many of which can
be attributed to the parameterization process.
An Open NMR experiment to perform high-throughput prediction of 13C
chemical shifts using a GIAO protocol is described. The data and analysis
were provided on publicly-available webpages to enable crowdsourcing, which
assisted in discovering an error rate of 6.1% in the starting data. The protocol
was refined during the work and shown to have an average unsigned error
of 2.24ppm for 13C nuclei of small, rigid molecules; comparable to the errors
observed elsewhere for general structures using HOSE and Neural Network
methods
Development of deep learning applications for the automated extraction of chemical information from scientific literature
This dissertation focuses on developing deep learning applications for extracting chemical information from scientific literature, particularly targeting the automated recognition of molecular structures in images. DECIMER Segmentation, a novel application, employs a Mask Region-based Convolutional Neural Network (MRCNN) model to segment chemical structures in documents, aided by a mask expansion algorithm, marking a significant advancement in processing chemical literature. The Optical Chemical Structure Recognition (OCSR) tool DECIMER Image Transformer uses an encoder-decoder architecture to convert chemical structure depictions into the machine-readable SMILES format. The model has been trained on over 450 million pairs of images and SMILES representations. Its ability to interpret various depiction styles, including hand-drawn structures, sets a new standard in OCSR. To artificially generate large and diverse OCSR training datasets using multiple cheminformatics toolkits, RanDepict was developed. The diversification of training data ensures robust model generalisation across different chemical structure depictions. A unique dataset of hand-drawn molecule images was created to evaluate the model's performance in interpreting these challenging depictions. This dataset further contributes to the understanding of automated structure recognition from diverse styles. The integration of these technologies led to the creation of DECIMER.ai, an open-source web application that combines segmentation and interpretation tools, allowing users to extract and process chemical information from literature efficiently. The work concludes with a discussion on the significance of open data in advancing molecular informatics, highlighting the potential to broader chemical research domains. By adhering to FAIR data standards and open-source principles, the tools developed for this dissertation are designed for adaptability and future development within the community
Theory and Applications for Advanced Text Mining
Due to the growth of computer technologies and web technologies, we can easily collect and store large amounts of text data. We can believe that the data include useful knowledge. Text mining techniques have been studied aggressively in order to extract the knowledge from the data since late 1990s. Even if many important techniques have been developed, the text mining research field continues to expand for the needs arising from various application fields. This book is composed of 9 chapters introducing advanced text mining techniques. They are various techniques from relation extraction to under or less resourced language. I believe that this book will give new knowledge in the text mining field and help many readers open their new research fields
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