Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Dimensions and position of the Eustachian tube in Humans.

Eustachian tube (ET) dysfunction is one of the causes for chronic otitis media. To develop new therapies such as stents to facilitate middle ear ventilation, a better knowledge on dimensions and positions of the ET in individual patients is necessary. Cone beam CT scans of 143 patients were retrospectively investigated. Parameters such as lengths of the ET and its cartilaginous and bony parts, diameters, angles as well as distance of the ostium from the nasal conchae were determined and evaluated for side, gender and age specific differences. The average length of the cartilaginous and bony tubes was smaller in women than men. The average deviation from the horizontal plane was 1.7° larger on the left side (35.4°) compared to the right side (33.7°). Tools to manipulate the ET or to insert stents into the ET should cover angles from at least 42° to 64°. The distance of the pharyngeal orifices from the conchae nasalis inferior increased with age, becoming most prominent above 70 years of age. This investigation provides necessary information to develop stents for human application and tools for safe positioning of the stents