Mass distributions of the system 136Xe + 208Pb at lab energies around the Coulomb barrier: a candidate reactions for production neutron-rich nuclei at N=126

Reaction products from the system 136Xe+208Pb at 136Xe ions laboratory energies of 700, 870, and 1020 MeV were studied by two-body kinematics and by a catcher-foil activity analysis to explore the theoretically proposed suitability of such reaction as a means to produce neutron-rich nuclei in the neutron shell closure N=126. Cross sections for products heavier than 208Pb were measured and were found sensibly larger than new theoretical predictions. Transfers of up to 16 nucleons from Xe to Pb were observed.peerReviewe

Rearrangement in the local, electronic and crystal structure of europium titanates under reduction and oxidation

We studied powder samples of europium titanates Eu1−x2+Eux3+TiO3+x/2 prepared by sol-gel and coprecipitation methods with subsequent thermal treatment of precursors at different conditions (reducing or oxidizing atmosphere, temperature, exposure time). We have revealed a radical rearrangement in the local, electronic and crystal structure of europium titanates depending on synthesis conditions. The combination of synchrotron X-ray diffraction (s-XRD), X-ray absorption (XANES and EXAFS), infrared and Raman spectroscopies supplemented by photoluminescence and simultaneous thermal analysis was used in our study. It is shown that the combined XANES and thermogravimetric analysis gives clear evidence of a change in the oxidation state of europium cations from Eu2+ to Eu3+. The comparison of s-XRD, XANES, and EXAFS data allowed us to explain the local structure rearrangement during the phase transition from cubic perovskite Eu2+TiO3 (space group Pm3¯m) to pyrochlore phase Eu23+Ti2O7 (space group Fd3¯m) through intermediate layered perovskite Eu23+Ti2O7 with monoclinic structure (space group P21) under annealing in oxidizing atmosphere. The Raman spectroscopy study pointed to significant changes in the local structure of the anionic sublattice upon the observed phase transitions. The analysis of luminescence spectra has shown that Eu3+ cations occupy positions with low local site symmetry in all synthesized compounds regardless of the type of the crystal structure. © 2020 Elsevier B.V

Analysis of 19.9 million publications from the PubMed/MEDLINE database using artificial intelligence methods: Approaches to the generalizations of accumulated data and the phenomenon of “fake news” [Анализ 19,9 млн публикаций базы данных PubMed/MEDLINE методами искусственного интеллекта: подходы к обобщению накопленных данных и феномен “fake news”]

Introduction. The English-language databases PubMed/MEDLINE and Embase are valuable information resources for finding original publications in basic and clinical medicine. Currently, there are no artificial intelligence systems to evaluate the quality of these publications. Aim. Development and testing of a system for sentiment analysis (i.e. analysis of emotional modality) of biomedical publications. Materials and methods. The technique of analysis of the “Big data” of biomedical publications was formulated on the basis of the topological theory of sentiment analysis. Algorithms have been developed that allow for the classification of texts from 16 sentiment classes with 90% accuracy (manipulative speech, research without positive results, propaganda, falsification of results, negative personal attitude, aggressive text, negative emotional background, etc.). Based on the algorithms, a scale for assessing the sentiment quality of research (β-score) is proposed. Results. Abstracts of 19.9 million publications registered in PubMed/MEDLINE over the past 50 years (1970–2019) were analyzed. It was shown that publications with low sentiment quality (the value of the β-score of the text is less than zero, which corresponds to the prevalence of manipulative and negative sentiments in the text) comprise only 18.5% (3.68 out of 19.9 million). The greatest values of the β-score were characterized by publications on sports medicine, systems biology, nutrition, on the use of applied mathematics and data mining in medicine. The rubrication of the entire array of publications by 27,840 headings (MESH-system of PubMed/MEDLINE) indicated an increase in the β-score by years (i.e., the positive dynamics of sentiment quality of the texts of publications) for 27,090 of the studied headings. The most intense positive dynamics was found for research in genetics, physiology, pharmacology, and gerontology. 249 headings with sharply negative dynamics of sentiment quality and with a pronounced increase in the manipulative sentiments characteristic of the tabloid press were highlighted. Separate assessments of international experts are presented that confirm the patterns identified. Conclusion. The proposed artificial intelligence system allows a researcher to make an effective assessment of the sentiment quality of biomedical research papers, filtering out potentially inappropriate publications disguised as “evidence-based”. Copyright © 2020, Farmakoekonomika. All rights reserved