Superconductivity in the Sn-Ba-Sr-Y-Cu-O system

Since Bednorz and Muller discovered high-T(sub c) superconductivity in the La-Ba-Cu-O compound, several families of superconducting oxides have been synthesized. Here, researchers report the results of search for superconductivity in the compounds based on tin, which has a lone electron pair like Bi, Tl, Pb. The following compounds were synthesized: Sn1Ba1Sr1Cu3Ox, Sn1Ba1Ca1Cu3Ox, Sn1Ba1Mg1Cu3Ox, Sn1Sr1Ca1Cu3Ox, Sn1Sr1Mg1Cu3Ox, Sn1Ca1Mg1Cu3Ox. The initial components were oxides and carbonates of the appropriate elements. Standard firing-grinding procedure was used. Final heating was carried out at 960 C during 12 hours. Then the samples were cooled inside the furnace. All the synthesis cycles were carried out in air atmosphere. Among the synthesized compounds only Sn1Ba1Sr1Cu3Ox showed remarkable conductivity. Other compounds were practically dielectrics. Presence of a possible superconductivity in Sn1Ba1Sr1Cu3Ox was defined by using the Meissner effect. At low temperature a deviation from paramagnetic behavior is observed. The hysteresis loops obtained at lower temperatures undoubtly testify to the presence of a superconductive phase in the sample. However, the part of the superconductive phase in the Sn1Ba1Sr1Cu3Ox ceramic turned out to be small, less than 2 percent, which agrees with the estimation from magnetic data. In order to increase the content of the superconductive phase two-valent cations Ba, Sr were partially substituted by univalent (K) and three-valent ones (Y)

A green chemical method for synthesis of bromine-containing “building blocks” for the production of photovoltaic polymers

Bromine-containing derivatives of aromatic and heteroaromatic compounds are the most important "building blocks" in the assembly of modern Photovoltaic Polymers (PV). While PV is being developed to produce "green" energy, converting sunlight to electricity, the reactions for producing brominated derivatives of building blocks described in the literature are examples of obsolete and environmentally dirty technologies. More environmentally harmful than bromination with molecular bromine [1] can only be bromination by molecular bromine in a concentrated hydrobromic acid medium [2]. Using 1,1'-diphenyl (1), 9H-diphenylcarbazole (2) and thiophene (3) as examples, we successfully tested the bromination of the above objects with a mixture of potassium bromide and bromate in acetic acid as outlined in the diagram

Эффективный поиск научных разработок с инновационным потенциалом в медицине

Medicine is one of the most important and rapidly developing branches of science. Research and developments projects run by scientific organizations and universities in this field are ultimately aimed at preserving the public health; these projects are expected to be rapidly implemented and become available to consumers. Yet in the area of medicine, the process of implementation can take many years. There is a gap between the developers (scientific organization, university), investors, and manufacturers due to the difficulty in assessing the innovation potential of the scientific results in medicine. The aim of this study was to determine the inclusion criteria for research conducted in medical universities to be incorporated in the innovation process; such criteria were supposed to be based on other (indirect) indicators ranking the medical universities. Material and methods. The study included twenty medical universities in Russia, largest in terms of the scientific and teaching staff. These universities were ranked according to the number of citations in the Web of Science over the period 2013-2017. Also, using the SciVal module developed by Elsevier, the number of publications with the participation of industrial partners was estimated. The assessment of the invention activity of medical universities was found in the materials published by the Russian Analytical Center “Expert”. Results. According to the scientometric analysis, medical universities with the most promising scientific products and scientific developments, have been in low demand by Russian and foreign companies. Conclusion. Due to the low activity of medical universities in implementing their intellectual production, potential investors and manufacturers should pay more attention to those medical universities, which produce a greater number of high-quality scientific results.Разработки, проводимые научными организациями и вузами в области медицины, направлены в конечном итоге на сохранение здоровья граждан, что должно подразумевать их быстрое внедрение в производство и распространение среди потребителей. Тем не менее процесс внедрения инноваций именно в области медицины может затягиваться на многие годы. Наблюдается разрыв между разработчиками (научная организация, вуз), инвесторами, производителями, основанный на сложности оценки инновационного потенциала результатов научной работы в области медицины. Цель – определение критериев поиска оригинальных результатов научной деятельности медицинских вузов для их включения в инновационный процесс на основании других показателей деятельности медицинских вузов. Материалы и методы. В исследование были включены двадцать крупнейших по числу научно-педагогических сотрудников (НПС) медицинских вузов России. Было проведено ранжирование этих вузов по числу цитирований в Web of Science за период 2013-2017 гг. Также с использованием модуля SciVal, разработанного компанией Elsevier, было оценено число публикаций, подготовленных с участием индустриальных партнеров. Произведена оценка изобретательской деятельности медицинских вузов на основании рейтинга изобретательской активности университетов России аналитического центра «Эксперт». Результаты. Медицинские вузы с наиболее перспективной научной продукцией и научными разработками по наукометрическим данным показали низкую на сегодняшний день востребованность этих разработок российскими и зарубежными компаниями. Выводы. В связи с невысоким уровнем активности медицинских вузов по внедрению результатов интеллектуальной деятельности потенциальным инвесторам и производителям при отборе следует уделить больше внимания разработкам медицинских вузов, выпускающих большее количество качественной научной продукции

A New Method for the Synthesis of Bromine-Containing Heterocyclic Compounds for Photovoltaic Polymers

With the development and improvement of systems for converting sunlight into electric and thermal energy, more and more work is emerging on the development of the newest and most promising direction in solar energy, namely the creation of solar cells based on photosensitive polymers. Recently the power conversion efficiency of organic photovoltaic (OPV) devices has overcome the barrier of 17%, and thus we can expect a new wave of scientific interest in the development of new, more efficient OPV devices. Unfortunately, during searching for highly efficient chemical structures of OPV polymers, the researchers missed an important point: all photovoltaic polymers consist of aromatic and heteroaromatic «building blocks», which, in turn, are synthesized based on outdated techniques using highly toxic, dangerous for life and environment precursors. The development of «green», environmentally friendly, economically viable methods for the synthesis of photovoltaic polymers and building blocks for their production, will make the energy obtained from OPV truly «green». In this work, we present an alternative, «green» method for synthesizing halogen-containing aromatic and heteroaromatic, expensive building blocks most commonly used in the synthesis of photovoltaic polymers, which can be used to obtain photovoltaic polymers of various structures. We present the original methods for the synthesis of 4,4-dibromo-1,1- biphenyl (1), 4,7-dibromo-2,1,3-benzothiadiazole (2), 2-bromothiophene (3) and 2,5-dibromothiophene (4). All these methods differ from the previously described routes by their simplicity and convenience of their implementation, the absence of corrosive and irritant reagents, good yield and compliance with the principles of «Green Chemistry»

Protic Ionic Liquid as Reagent, Catalyst, and Solvent: 1-Methylimidazolium Thiocyanate

We propose a new concept of the triple role of protic ionic liquids with nucleophilic anions: a) a regenerable solvent, b) a Brønsted acid inducing diverse transformations via general acid catalysis, and c) a source of a nucleophile. The efficiency of this strategy was demonstrated using thiocyanate-based protic ionic liquids for the ring-opening of donor-acceptor cyclopropanes. A wide variety of activated cyclopropanes were found to react with 1-methylimidazolium thiocyanate under mild metal-free conditions via unusual nitrogen attack of the ambident thiocyanate ion on the electrophilic center of the three-membered ring affording pyrrolidine-2-thiones bearing donor and acceptor substituents at the C(5) and C(3) atoms, respectively, in a single time-efficient step. The ability of 1-methylimidazolium thiocyanate to serve as a triplex reagent was exemplarily illustrated by (4+2)-annulation with 1-acyl-2-(2-hydroxyphenyl)cyclopropane, epoxide ring-opening and other organic transformations

Microstructure and biodegradation performance of Mg–4Ca–1Zn based alloys after ultrasonic treatment and doping with nanodiamonds for biomedical applications

This work aims to study microstructural features, phase composition, topology, surface potential, and the biodegradation performance of Mg–4Zn–1Ca-based alloys whose melts were ultrasonically (US) treated and doped with nanodiamonds (ND). The findings show a correlation between the ratio of the secondary phase segregated along the grain boundaries and the biodegradation rate in the RPMI-1640 synthetic culture medium. The fewer Ca2Mg6Zn3 phase fraction, the lower the biodegradation rate. Also, ND doping does not significantly affect the biodegradation rate. Intriguingly, the latter in the US-treated alloy was found to be noticeably inhibited due to a smoother topography and the presence of the fewest Ca2Mg6Zn3 phase fraction segregated along the grain boundaries. Further studies are needed to assess the biodegradable potential of the ND doped alloy, which melt was ultrasonically treated

МЕДИЦИНСКИЕ ВУЗЫ РОССИИ В МЕЖДУНАРОДНЫХ РЕЙТИНГАХ: СРАВНЕНИЕ НАУКОМЕТРИЧЕСКИХ КРИТЕРИЕВ

Introduction. Currently, globalization and market economy have led to the necessary improving competitiveness of the universities. The parameters of academic efficiency along with reputation indicators become the main criteria for inclusion in international and domestic rankings and thus affect the financial well-being of the university.The objective of this study is to compare the indicators of scientific activity of the largest Russian medical universities and the foreign non-English speaking university that conducts training in medicine, according to data obtained from scientometric databases and to determine the prospects for including Russian medical universities into the leading international rankings.Material and methods. The publication activity of 9 largest Russian medical universities for 5 years was analyzed: the number of articles and the number of citations. For comparison, we used data from a similar number of employees of a foreign university that trains students in medicine, included in international rankings. The sources were the Scopus database, as well as international rankings: Times Higher Education, Academic Ranking of World Universities and QS World University Rankings.Results. Only two Russian medical universities are mentioned in the bottom lines (1000+) in the THE ranking and none of them fall into the QS WUR ranking. However, while maintaining the current trends of increasing the number of publications in Scopus, in the next 2–3 years there are prospects for inclusion in the THE ranking of «Pavlov First Saint Petersburg State Medical University» and «A. I. Yevdokimov Moscow State University of Medicine and Dentistry». Conclusion. Based on the analysis of publication activity of the largest medical universities in Russia, it can be noted that it is necessary to develop international scientific cooperation and develop strategies for improving self citation in universities, and also need to work more actively with graduates and their employers.Введение. В настоящее время глобализация и рыночная экономика привели к необходимости повышения конкурентоспособности вуза. Параметры академической эффективности, наряду с репутационными показателями, становятся основными критериями для включения в международные и отечественные рейтинги и влияют, таким образом, на финансовое благополучие вуза.Цель – сравнение показателей научной деятельности крупнейших медицинских вузов РФ и крупного зарубежного неанглоязычного университета, проводящего подготовку по медицине, по данным, полученным из наукометрических ресурсов, и определение перспектив включения медицинских вузов России в ведущие международные рейтинги.Материал и методы. Была проанализирована публикационная активность 9 крупнейших медицинских вузов России за 5 лет: количество статей и количество цитирований. Для сравнения использованы данные подобного по числу сотрудников зарубежного университета, ведущего подготовку студентов по медицине, включенного в международные рейтинги. Источниками стали база данных Scopus, а также данные международных рейтингов Times Higher Education, Academic Ranking of World Universities и QS World University Rankings. Результаты. Лишь два российских медицинских университета занимают нижние строчки (1000+) в рейтинге THE, и ни один из них не попадает в рейтинг QS WUR. Однако при сохранении существующих тенденций к росту числа публикаций в Scopus в ближайшие 2–3 года есть перспективы включения в рейтинг THE у ПСПбГМУ им. И. П. Павлова и МГСМУ им. А. И. Евдокимова. Выводы. На основании анализа публикационной активности крупнейших медицинских вузов России можно отметить, что необходимо развивать международное научное сотрудничество и разработать стратегии повышения цитируемости в самих вузах, а также необходимо проводить более активную работу со своими выпускниками и их работодателями.

Experience of eradicating parasites of laboratory rats in conventional vivarium

The purpose of the research is to test different dehelminthization schemes of laboratory rats infected with cestodes Rodentolepis nana and nematodes Syphacia muris and evaluate the significance of combined environment disinfection measures. The practical experience of eradication (helminth eradication) in animals in a conventional vivarium was described.Materials and methods. Experiments were conducted to study the efficacy of anthelmintics and administration schemes against cestode and nematode infections in laboratory rats. In the first experiment, praziquantel was used at a dose of 10 mg/kg to treat rats infected with R. nana. In the second experiment, the comparative efficacy of fenbendazole, albendazole, and pyrantel was evaluated against syphaciosis at the recommended dosages of 20, 10, and 12.5 mg/kg, respectively. Each drug was given orally, individually, twice with an interval of 7 days. The third experiment tested different schemes for treating syphaciosis with fenbendazole. One group of rats was given the drug orally individually using an esophageal tube at a dose of 20 mg/kg once a day for 7 consecutive days. Other groups were given fenbendazole daily with food for 7 days (150 mg fenbendazole per 1 kg of food). In all three experiments, all animals were divided into groups, and their cells underwent a complex of additional disinfection measures, and those kept in cages without disinfection.Results and discussion. Praziquantel showed 100% efficacy at a single dose of 10 mg/kg in R. nana therapy. In animals without additional disinfection procedures, cestode eggs were again recorded starting from day 14 after the drug administration. In the group of animals with disinfection measures, pathogens were not detected during the experiment. Double administration of fenbendazole, albendazole and pyrantel in the recommended dosages against syphaciosis did not result in eradicated nematodes in the animals. The disinfection did not affect the obtained results. Fenbendazole administered daily for 7 days ensured helminth eradication in animals. However, on day 7 after the therapy, Syphacia sp. eggs were again found in the groups that received the drug individually intragastrically through a tube, regardless of whether their cells were disinfected. The animals that received fenbendazole with food and were regularly disinfested remained free from nematodes throughout the experiment until the additional disinfection measures were cancelled. In the absence of disinfection, released helminth eggs were recorded on day 14 after therapy

Does the Increase of the Scientific Achievements Lead to Decrease in the Quality of Education?

This research article is devoted to the problem of training personnel with higher medical education during the transition to an independent assessment of the graduates’ qualifications and new requirements for the effectiveness of scientific work of universities. The aim of this work was to study the correspondence between the quality of graduate training and the scientific productivity of medical universities. The authors analyzed the results of the accreditation examination of graduates of medical universities as an indicator of the quality of specialists’ training and scientometric indicators in the relevant specialty. As a result of the data analysis, the problem of discrepancy between high scientific productivity of universities and successful completion of accreditation by young specialists was revealed. The authors believe that a possible reason for this discrepancy is the high load on the teaching staff. Furthermore, detailed study of this problem is needed and, most likely, a revision of the approach to the work organization of medical universities’ teaching staff.Эта исследовательская статья посвящена проблеме подготовки кадров с высшим медицинским образованием в период перехода к независимой оценке квалификации выпускников вузов и новых требований к результативности научной работы данных организаций. Цель проведенной авторами работы – изучение связи между качеством подготовки выпускников и научной продуктивностью медицинских высших учебных заведений. В ходе анализа результатов аккредитационного экзамена выпускников медицинских вузов как показателя качества подготовки специалистов и наукометрических показателей по соответствующей специальности выявлена проблема несоответствия между высокой научной продуктивностью вузов и успешным прохождением аккредитации молодыми специалистами. Авторы проведенного исследования полагают, что возможной причиной такого несоответствия является высокая нагрузка на профессорско-преподавательский состав. Необходимо дальнейшее более детальное изучение данной проблемы и, вероятно, потребуется пересмотр подхода к организации работы преподавательского состава медицинских вузов

Экологобезопасные технологии применения отходов промышленности при регенерации асфальтобетонных покрытий

The development of a technology for the regeneration of used asphalt concrete coatings is presented, provided that industrial wastes are used and environmentally friendly asphalt concrete coatings are obtained. For research, the technology of dispersing and mixing the waste was chosen to achieve its homogeneity and activation of the mixture in order to increase the physicochemical interaction with binders. It was shown that heavy metals contained in waste and in asphalt granulate are reliably blocked in materials based on organohydraulic binders (OHB), their migration to the environment is significantly reduced. With the optimum content of bitumen emulsion and cement, the effect of maximum structural strength of the road building material and maximum fixation of heavy metal ions is observed. The proposed technical solutions are supported with theoretical calculations and allow environmental-friendly regeneration of asphalt concrete pavements.Представлена разработка технологии регенерации отработанных асфальтобетонных покрытий при условии применения отходов промышленности и получения экологически безопасных асфальтобетонных покрытий. Для исследований выбрана технология диспергирования и перемешивания отходов для достижения их однородности и активации смеси с целью повышения физико-химического взаимодействия с вяжущими веществами. Показано, что в материалах на органогидравлических вяжущих тяжелые металлы, содержащиеся в отходах и в асфальтогрануляте, надежно блокируются, их миграция в окружающую среду существенно снижается. При оптимальном содержании битумной эмульсии и цемента наблюдается эффект максимальной структурной прочности дорожностроительного материала и максимальной фиксации ионов тяжелых металлов. Предложенные технические решения обоснованы теоретическими расчетами и позволяют осуществлять экологобезопасную регенерацию асфальтобетонных покрытий