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

Vibrational analysis of 1,8-dichlorooctane

696-702 Fourier transform infrared (FT-IR) and Raman spectra of the organic compound 1,8-dichlorooctane (1,8-DCO) have been recorded in the range 4000-400cm-1 and 3500-100 cm-1, respectively. A detailed vibrational analysis in terms of assignment of observed frequencies of this molecule for its four most probable conformations in liquid state, having all its carbon atoms in the same plane, with symmetries C2h, Ci, C2 and C1 has been done. A systematic set of symmetry coordinates has been constructed for this molecule and normal coordinate calculations are carried out using the computer program MOLVIB. The force-field transferred from already studied lower chain chloro-alkanes is subjected to refinement so as to fit the observed frequencies with that of calculated ones. The potential energy distribution (PED) has been calculated for each mode of vibration of the molecule for the assumed conformations. </smarttagtype

Vibrational analysis of 1-chlorononane

679-685Fourier transform infrared and Raman spectra of the organic compound 1-chlorononane have been recorded in its liquid state at ambient temperature in the ranges 4000-400 cm-1 and 3200-150 cm-1, respectively. A detailed vibrational analysis in terms of assignment of the observed vibrational bands of 1-chlorononane has been done to different modes of vibrations for its four most probable conformations with symmetries Cs and C1 in its liquid phase with the aid of normal co-ordinate calculations. The normal co-ordinate calculations have been carried out utilizing the computer program MOLVIB. The potential energy distribution has also been calculated for each mode of vibration

Higher-Order Amplitude Squeezing in Six-Wave Mixing Process

We investigate theoretically the generation of squeezed states in spontaneous and stimulated six-wave mixing process quantum mechanically. It has been found that squeezing occurs in field amplitude, amplitude-squared, amplitude-cubed, and fourth power of field amplitude of fundamental mode in the process. It is found to be dependent on coupling parameter “g” (characteristics of higher-order susceptibility tensor) and phase values of the field amplitude under short-time approximation. Six-wave mixing is a process which involves absorption of three pump photons and emission of two probe photons of the same frequency and a signal photon of different frequency. It is shown that squeezing is greater in a stimulated interaction than the corresponding squeezing in spontaneous process. The degree of squeezing depends upon the photon number in first and higher orders of field amplitude. We study the statistical behaviour of quantum field in the fundamental mode and found it to be sub-Poissonian in nature. The signal-to-noise ratio has been studied in different orders. It is found that signal-to-noise ratio is higher in lower orders. This study when supplemented with experimental observations offers possibility of improving performance of many optical devices and optical communication networks

Vibrational analysis of 1-bromooctane

172-182Fourier transform infrared and Raman spectra of the organic compound 1-bromooctane have been recorded in the range 4000-400 cm-1 and 3500-100 cm-1, respectively. A detailed vibrational analysis in terms of assignment of the observed frequencies of this molecule for its four most probable conformations in liquid phase, having symmetries Cs and C1, has been done using normal co-ordinate calculations. The force-field transferred from already studied lower chain bromo-alkanes is subjected to refinement so as to fit the observed infrared and Raman frequencies with those of the calculated ones. The potential energy distribution has also been calculated for each mode of vibration of the molecule for the most probable conformations present in its liquid phase

THERMOLUMINESCENCE CHARACTERISTICS OF CaS: Ce NANOPHOSPHORS

The thermoluminescence characteristics of cerium doped calcium sulphide nanoparticles under UV radiations have been studied. The average grain size of the nanoparticles is found to be 53nm which is confirmed by TEM micrograph. The TL glow curve shows a single peak at 376K. TL intensity increases linearly unto 2hr UV exposure. Further increase in the dose results into a decrease of TL intensity. Variation in TL intensity as a function of cerium concentration is studied and 0.4mol% is found to be the optimum concentration for TL. The trap parameters namely, activation energy (E), order of kinetics (b) and frequency factor (s) of CaS: Ce (0.4 mole %) sample have been determined using Chen&apos;s method. The order of Kinetics is found to be 2 indicating retrapping of charge carriers in CaS: Ce nanoparticles. The effect of different heating rates has also been studied. The PL emission spectrum shows two peaks at 506nm and 565nm when excited at 450nm

Thermoluminescence Characteristics of CaS: Ce Nanophosphors

The thermoluminescence characteristics of cerium doped calcium sulphide nanoparticles under UV radiations have been studied. The average grain size of the nanoparticles is found to be 53nm which is confirmed by TEM micrograph. The TL glow curve shows a single peak at 376K. TL intensity increases linearly unto 2hr UV exposure. Further increase in the dose results into a decrease of TL intensity. Variation in TL intensity as a function of cerium concentration is studied and 0.4mol% is found to be the optimum concentration for TL. The trap parameters namely, activation energy (E), order of kinetics (b) and frequency factor (s) of CaS: Ce (0.4 mole %) sample have been determined using Chen&apos;s method. The order of Kinetics is found to be 2 indicating retrapping of charge carriers in CaS: Ce nanoparticles. The effect of different heating rates has also been studied. The PL emission spectrum shows two peaks at 506nm and 565nm when excited at 450nm

Bandgap modification of TiO2 sol-gel films by Fe and Ni doping

Nickle and iron doped TiO2 thin films were prepared on glass substrates by sol–gel dip coating process. Indirect and direct optical energy gaps were calculated with the incorporation of different concentrations of both the ions. Indirect bandgap was found to be a strong function of the dopant concentration, whereas direct energy gap has negligible dependence on the nature of dopant and its concentration. Direct energy gap has always been found to retain a value higher than the indirect energy gap. Variation of observed energy gap properties shows a trend similar to that reported on the basis of numerical calculations or the samples obtained by other techniques. Increase in refractive index and corresponding density of the film sample does not support the change in turn over frequency. The influence of crystalline phase change is also ruled out by XRD investigations. It is concluded that red shift of band edge absorption takes place by incorporation of dopant and sol–gel dip coating technique offers an effective low cost route to the production of these coatings