Giant Room-Temperature Power Factor in p-Type Thermoelectric SnSe under High Pressure

Materials that can efficiently convert heat into electricity are widely utilized in energy conversion technologies. The existing thermoelectrics demonstrate rather limited performance characteristics at room temperature, and hence, alternative materials and approaches are very much in demand. Here, it is experimentally shown that manipulating an applied stress can greatly improve a thermoelectric power factor of layered p‐type SnSe single crystals up to ≈180 µW K(−2) cm(−1) at room temperature. This giant enhancement is explained by a synergetic effect of three factors, such as: band‐gap narrowing, Lifshitz transition, and strong sample deformation. Under applied pressure above 1 GPa, the SnSe crystals become more ductile, which can be related to changes in the prevailing chemical bonding type inside the layers, from covalent toward metavalent. Thus, the SnSe single crystals transform into a highly unconventional crystalline state in which their layered crystal stacking is largely preserved, while the layers themselves are strongly deformed. This results in a dramatic narrowing in a band gap, from E (g) = 0.83 to 0.50 eV (at ambient conditions). Thus, the work demonstrates a novel strategy of improving the performance parameters of chalcogenide thermoelectrics via tuning their chemical bonding type, stimulating a sample deformation and a band‐structure reconstruction

Sсandium(III) Beta-diketonate Derivatives as Precursors for Oxide Film Deposition by CVD

AbstractComplexes with acetylacetone Sc(acac)3, dipivaloylmethane Sc(thd)3, 2,2,6,6–tetramethyl-4-fluoro-3,5-heptanedione Sc(tfhd)3, pivaloyltrifluoroacetone Sc(ptac)3, trifluoroacetylacetone Sc(tfac)3, and hexafluoroacetylacetone Sc(hfac)3 were synthesized, purified and identified by elemental analysis, m.p., IR and NMR spectroscopy, and mass spectrometry. The thermal behaviour of the synthesized compounds in the solid state was investigated by the method of difference-scanning calorimetry in vacuum. As a result the thermodynamic characteristics of the melting processes were determined. The temperature dependences of saturated and unsaturated vapour pressure of complexes under study were measured by static method with membrane-gauge manometers. The average molecular weight of gas calculated from the experimental data on unsaturated vapours using ideal gas law was close to the molecular weight of monomer for all investigated compounds. Decomposition temperatures of compounds under study were defined as the temperature above that pressure changes became irreversible. The information about melting and decomposition processes were taken into account at measuring saturated vapour pressure of complexes. The row of volatility Sc(hfac)3 > Sc(ptac)3 > Sc(tfac)3 > Sc(thd)3 ≥ Sc(tfhd)3 > Sc(acac)3 was determined from the p–T dependences obtained. Above information about thermal behaviour of complexes enabled one to use it as a guide for CVD experiments aimed at achieving oxide films with high optical properties. Precursor chosen for film deposition was Sc(thd)3 The Sc2O3 film deposition conditions were following: the gas-carrier rate 1 l/h, He gas-reagent rate 10 l/h, total pressure 10 Torr, evaporator temperature 105-110̊С, substrate temperature 450- 650̊С, substrate Si(100). Ellipsometry was applied to characterize the film thickness and refractive index. The morphology and the composition of the films were determined with XPS and SEM

V. N. Vinogradov Faculty Therapy Clinic of Sechenov University: the flagship of the therapeutic service of the Russian Federation. A review

The history of the Faculty Therapy Clinic of Sechenov University is presented. The stages of the formation of its therapeutic school are discussed. Diagnostic and therapeutic methods first developed and implemented in the clinic are described in detail

Hydrogen permeability of the Pd–Pb system foil of various composition

The purpose of the study was identification of the role of the chemical composition of Pd, Pb-alloys based of palladium in the processes of injection and extraction of atomic hydrogen. The objects of study were Pd-Pb alloy foils with a lead content of 3, 5, 7, 9, and 11 at. %, representing the b-phase of the solid solution. Samples with a thickness of 40 to 62 µm were obtained by cold rolling. Hydrogen permeability was studied by cyclic voltammetry and two-stage cathode-anode chronoamperometry in deaerated solutions of 0.1 M H2SO4. The obtained results were processed according to a mathematical model developed for electrodes of semi-infinite thickness. The dependence of the hydrogen permeability coefficient, as well as the rate constants of the processes of injection and extraction of atomic hydrogen, on the chemical composition of the alloy has been revealed. It was found that the Pd–Pb alloy with a lead content of 5 at.% demonstrates the highest values of hydrogen permeability compared with samples of the same crystal structure, since the rate constant of atomic hydrogen injection is very sensitive to the alloy structure. The latter confirms that the phase-limiting transition of atomic hydrogen into the alloy is the rate-determining stage, at least in the initial period of time

Cytotoxicity of albebetin oligomers depends on cross-β-sheet formation

AbstractPrefibrillar cytotoxicity was suggested as a common amyloid characteristic. We showed two types of albebetin prefibrillar oligomers are formed during incubation at pH 7.3. Initial round-shaped oligomers consist of 10–15 molecules determined by atomic force microscopy, do not bind thioflavin-T and do not affect viability of granular neurons and SH-SY5Y cells. They are converted into ca. 30–40-mers possessing cross-β-sheet and reducing viability of neuronal cells. Neither monomers nor fibrils possess cytotoxicity. We suggest that oligomeric size is important for stabilising cross-β-sheet core critical for cytotoxicity. As albebetin was used as a carrier-protein for drug delivery, examination of amyloidogenicity is required prior polypeptide biomedical applications

Personalizing the Way of Teaching LSP

Introduction. The problem of effective teaching language for special purposes (LSP) to the students of non-linguistic professions has been discussed for a long time and in full details by academicians both in Russia and foreign countries. As the result of multiple and thorough surveys general problems of the given situation have been revealed, the way out being defined as special training/retraining of LSP teachers. But in language education publications it is hardly possible to find the description of the program aiming at the training of the above mentioned teachers. The aim of the article is to present effective approaches to teaching LSP and offer the developed master program “Methods of teaching LSP” as a means to solve the problems mentioned above. Materials and Methods. The research methods used are a combination of analytical review of studies by Russian and foreign researchers and interpretation of the results obtained by interviewing university teachers specializing in teaching foreign languages to students completing Bachelorʼs or Masterʼs degree programs. The survey was conducted to assess the level of readiness of professional educators to design the structure and content of programs for teaching LSP, and actually conduct classes within the specified language-teaching area, 81 teachers being responders. Results. As a result of the undertaken review of theoretical works and analysis of the conducted survey a master program “Methods of teaching LSP” was designed for training graduates who will then teach English or Russian as a foreign language at industry-specific higher schools. The developed program focuses on instructing future LSP educators to work out a personalized educational route adjusted to the level of foreign language skills of a student and their prospective professional activities. Discussion and Conclusion. The master program developed by the authors as well as the content of the subjects suggested as its integral part are expected to become a productive way of training LSP educators who are supposed to acquire a number of special skills and competences described in the article. Distant learning and e-learning technologies are also engaged in the program to facilitate learners’ more efficient independent activities. The master program is seen as one of the means of modernizing LSP teachers’ professional training which meets the long-term needs of the Russian education system

Tickborne Pathogen Detection, Western Siberia, Russia

Ixodes and Dermacentor ticks harbor Borrelia, Anaplasma/Ehrlichia, Bartonella, and Babesia species

Study Protocol for an Online Questionnaire Survey on Symptoms/Signs, Protective Measures, Level of Awareness and Perception Regarding COVID-19 Outbreak among Dentists. A Global Survey

The Centres for Disease Control and Prevention and the World Health Organization have developed preparedness and prevention checklists for healthcare professionals regarding the containment of COVID-19. The aim of the present protocol is to evaluate the impact of the COVID-19 outbreak among dentists in different countries where various prevalence of the epidemic has been reported. Several research groups around the world were contacted by the central management team. The online anonymous survey will be conducted on a convenience sample of dentists working both in national health systems and in private or public clinics. In each country/area, a high (~5–20%) proportion of dentists working there will be invited to participate. The questionnaire, developed and standardized previously in Italy, has four domains: (1) personal data; (2) symptoms/signs relative to COVID-19; (3) working conditions and PPE (personal protective equipment) adopted after the infection’s outbreak; (4) knowledge and self-perceived risk of infection. The methodology of this international survey will include translation, pilot testing, and semantic adjustment of the questionnaire. The data will be entered on an Excel spreadsheet and quality checked. Completely anonymous data analyses will be performed by the central management team. This survey will give an insight into the dental profession during COVID-19 pandemic globally

Antitumor Activity of Auger Electron Emitter 111In Delivered by Modular Nanotransporter for Treatment of Bladder Cancer With EGFR Overexpression

Gamma-ray emitting 111In, which is extensively used for imaging, is also a source of short-range Auger electrons (AE). While exhibiting negligible effect outside cells, these AE become highly toxic near DNA within the cell nucleus. Therefore, these radionuclides can be used as a therapeutic anticancer agent if delivered precisely into the nuclei of tumor target cells. Modular nanotransporters (MNTs) designed to provide receptor-targeted delivery of short-range therapeutic cargoes into the nuclei of target cells are perspective candidates for specific intracellular delivery of AE emitters. The objective of this study was to evaluate the in vitro and in vivo efficacy of 111In attached MNTs to kill human bladder cancer cells overexpressing epidermal growth factor receptor (EGFR). The cytotoxicity of 111In delivered by the EGFR-targeted MNT (111In-MNT) was greatly enhanced on EJ-, HT-1376-, and 5637-expressing EGFR bladder cancer cell lines compared with 111In non-targeted control. In vivo microSPECT/CT imaging and antitumor efficacy studies revealed prolonged intratumoral retention of 111In-MNT with t½ = 4.1 ± 0.5 days as well as significant dose-dependent tumor growth delay (up to 90% growth inhibition) after local infusion of 111In-MNT in EJ xenograft-bearing mice