A transverse current rectification in graphene superlattice

A model for energy spectrum of superlattice on the base of graphene placed on the striped dielectric substrate is proposed. A direct current component which appears in that structure perpendicularly to pulling electric field under the influence of elliptically polarized electromagnetic wave was derived. A transverse current density dependence on pulling field magnitude and on magnitude of component of elliptically polarized wave directed along the axis of a superlattice is analyzed.Comment: 12 pages, 6 figure

Formation of double shell during implosion of plasma metal puff Z-pinches

This work presents the results of experimental and theoretical research of impact of tailored density profile and application of external axial magnetic field on initial spatial distribution of the plasma density in the plasma metal puff Z-pinch and on its implosion dynamics. It has been discovered that upon implosion of the plasma metal puff Z-pinch some stripes interpreted as the system of two coaxial shells appear on the optical images. With the help of numerical simulation, the formation of the plasma liner consisting of a mixture of carbon and bismuth ions and formed by the expansion of the plasma jet of the arc burning on the bismuth electrode has been considered in this work. It has been shown that the lightweight carbon ions facilitate formation of the density distribution smoothly decreasing with the increase in radius, that, in turn, leads to suppression of the Rayleigh-Taylor instability in the current sheath upon further implosion. It has also been demonstrated that availability of the two types of ions in plasma considerably different in mass leads to formation (in the compression phase) of a double shell with externally located heavy ions. It has also been revealed that the application of the external axial magnetic field leads to reduction in the plasma metal puff Z-pinch initial diameter. © 2020 Author(s).This work was funded by Russian Science Foundation. Project No. 19–19-00127

Reorganization of a 2D disordered granular medium due to a small local cyclic perturbation

We measure experimentally the rearrangements due to a small localized cyclic displacement applied to a packing of rigid grains under gravity in a 2D geometry. We analyze the evolution of the response to this perturbation by considering the individual particle displacement and the coarse grained displacement field, as well as the mean packing fraction and coordination number. We find that the displacement response is rather long ranged, and evolves considerably with the number of cycles. We show that a small difference in the preparation method (induced by tapping the container) leads to a significant modification in the response though the packing fraction changes are minute. Not only the initial response but also its further evolution change with preparation, demonstrating that the system still retains a memory of the initial preparation after many cycles. Nevertheless, after a sufficient number of cycles, the displacement response for both preparation methods converges to a nearly radial field with a 1/r decay from the perturbation source. The observed differences between the preparation methods seem to be related to the changes in the coordination number (which is more sensitive to the evolution of the packing than the packing fraction). Specifically, it may be understood as an effect of the breaking of local arches, which affects the lateral transmission of forces.Comment: 13 pages, revised and resubmitted to J. Stat. Mech.: Theory and Exp. (JSTAT

Изучение бактериальных сообществ многолетнемерзлых пород оазисов Антарктиды методами культивирования

Aerobic and anaerobic bacteria from the permafrost of King George Island, Schirmacher, Larsemann, Banger oases and Hobbs Coast have been cultured. Based on the qualitative and quantitative composition of the cultivated community of samples, a comparative analysis of the biodiversity of marine, lake and fluvioglacial deposits of different geocryological conditions and age was made.Проведено культивирование аэробных и анаэробных бактерий из многолетнемерзлых пород острова Кинг Джордж, оазисов Ширмахера, Холмы Ларсеманн, Бангера и Берега Хоббса. На основе качественного и количественного состава культивируемого сообщества образцов проведена сравнительная характеристика разнообразия морских, озерных и флювиогляциальных отложений различных геокриологических условий и возраста

Microbial and Geochemical Evidence of Permafrost Formation at Mamontova Gora and Syrdakh, Central Yakutia

Biotracers marking the geologic history and permafrost evolution in Central Yakutia, including Yedoma Ice Complex (IC) deposits, were identified in a multiproxy analysis of water chemistry, isotopic signatures, and microbial datasets. The key study sections were the Mamontova Gora and Syrdakh exposures, well covered in the literature. In the Mamontova Gora section, two distinct IC strata with massive ice wedges were described and sampled, the upper and lower IC strata, while previously published studies focused only on the lower IC horizon. Our results suggest that these two IC horizons differ in water origin of wedge ice and in their cryogenic evolution, evidenced by the differences in their chemistry, water isotopic signatures and the microbial community compositions. Microbial community similarity between ground ice and host deposits is shown to be a proxy for syngenetic deposition and freezing. High community similarity indicates syngenetic formation of ice wedges and host deposits of the lower IC horizon at the Mamontova Gora exposure. The upper IC horizon in this exposure has much lower similarity metrics between ice wedge and host sediments, and we suggest epigenetic ice wedge development in this stratum. We found a certain correspondence between the water origin and the degree of evaporative transformation in ice wedges and the microbial community composition, notably, the presence of Chloroflexia bacteria, represented by Gitt-GS-136 and KD4-96 classes. These bacteria are absent at the ice wedges of lower IC stratum at Mamontova Gora originating from snowmelt, but are abundant in the Syrdakh ice wedges, where the meltwater underwent evaporative isotopical fractionation. Minor evaporative transformation of water in the upper IC horizon of Mamontova Gora, whose ice wedges formed by meltwater that was additionally fractionated corresponds with moderate abundance of these classes in its bacterial community. © Copyright © 2021 Cherbunina, Karaevskaya, Vasil’chuk, Tananaev, Shmelev, Budantseva, Merkel, Rakitin, Mardanov, Brouchkov and Bulat.We thank Samsonova Vera, Karzhavin Vladimir, Pankov Alexander, Andreevskaya Maya and Alexander Osipov for their for their invaluable assistance in field work

Состояние больных саркоидозом исходно и 10 лет спустя при различной тактике их ведения (мультицентровый анализ)

Summary. A multicenter (12 centers) retrospective analysis of health status of 83 sarcoidosis patients in time of diagnosis and after 10 years of treatment has been performed. In 10 years after diagnosis, 47 % of the patients had complete remission of pulmonary manifestations; mean forced spirometric values have not reduced in 10 years (excluding patients initially treated with anti-TB drugs). Patients treated with systemic steroids initially or during 10 yrs were less likely to have the complete remission (36.5 %) and more likely to have recurrent sarcoidosis course (57.1 %) compared to those not treated with systemic steroids. Pentoxifylline administration positively influenced the remission rate (71.4 %) and relapse rate in patients who had not received immunosuppressive therapy (28.6 %). A tendency has been found to positive effects of essential phospholipids on relapse rate and remission rate in sarcoidosis. Anti-TB therapy or treatment of sarcoidosis patients in TB centers negatively influenced the outcome of sarcoidosis. The results disclose an urgent need to imply new approaches to treatment of sarcoidosis, eg. anti-TNF-α drugs

Саркоидоз: федеральные клинические рекомендации по диагностике и лечению

Sarcoidosis is a multi-organ granulomatosis  of unknown  origin. Modern  diagnostic methods  allow detecting  this disease at an early stage. The absence of specific markers requires a comprehensive  approach  to diagnosis based on comparison  of radiation,  clinical, morphological  and functional data. The course of sarcoidosis without damage to the respiratory system presents significant difficulties. It is extremely important  to understand the time and means of starting Sarcoidosis’s treatment to avoid the early initiation  of hormones  and cytostatics and, on the other hand,  to timely respond to progression and threatening  conditions.  Methods. Clinical recommendations are based on the analysis of Russian and English publications of the latest sarcoidosis research. The target audience of these clinical guidelines are therapists, general practitioners, pulmonologists, TB doctors, rheumatologists,  dermatologists,  radiation diagnosticians,  immunologists,  and clinical pharmacologists.  Each thesis-recommendation for diagnosis and treatment is evaluated on an 1 to 5 scale of levels of evidence and an A, B, C scale of the grades of recommendations. The clinical guidelines also contain comments and explanations for the theses-recommendations, diagnostic algorithms, treatment strategies, reference materials on the use of recommended drugs. Conclusion. Current information  on epidemiology, clinical manifestations,  diagnosis and management  strategies for patients with sarcoidosis are covered in the presented clinical guidelines. Approved by the decision of the Scientific and Practical Council of the Ministry of Health of the Russian Federation (2022).Саркоидоз является полиорганным гранулематозом неизвестной природы. При помощи  современных методов диагностики это заболевание возможно выявить на ранних стадиях. Для установления диагноза на основании сопоставления лучевых, клинических, морфологических и функциональных данных при отсутствии специфических маркеров требуется комплексный поход. Варианты течения саркоидоза без поражения органов дыхания представляют  значительные трудности. Во избежание  раннего  назначения гормонов  и цитостатических препаратов и, наоборот, в целях своевременного реагирования на прогрессирование и угрожающие состояния крайне актуально понимание времени  и средств  начала  лечения  саркоидоза.  Методы. Клинические рекомендации созданы  на основании анализа данных последних исследований саркоидоза, опубликованных на русском и английском языках. Каждый  тезис-рекомендация по проведению диагностических и лечебных мероприятий оценивается по шкалам оценки  уровня достоверности доказательств (1–5)  и убедительности  рекомендаций (по категориям  А, В, С). Клинические рекомендации содержат также комментарии и разъяснения к указанным тезисам-рекомендациям, алгоритмы  по диагностике, тактике терапии,  справочные материалы по использованию рекомендуемых препаратов. Целевой  аудиторией  данных  клинических рекомендаций являются  терапевты,  врачи  общей  практики,  пульмонологи, фтизиатры,  ревматологи,  дерматологи,   специалисты  лучевой  диагностики,  иммунологи, клинические  фармакологи.  Заключение. По данным представленных клинических рекомендаций освещаются современные сведения об эпидемиологии, клинических проявлениях,  диагностике и тактике  ведения  пациентов с саркоидозом. Одобрены  решением Научно-практического совета  Министерства здравоохранения Российской Федерации (2022)

Une trop grande dématérialisation de la dépossession fait perdre le bénéfice du gage avec entiercement

International audience(Com. 8 avr. 2015, n° 14-13.787, RLDC juin 2015, p. 36, obs. E. Pouliquen