Stable topological textures in a classical 2D Heisenberg model

We show that stable localized topological soliton textures (skyrmions) with $\pi_2$ topological charge $\nu \geq 1$ exist in a classical 2D Heisenberg model of a ferromagnet with uniaxial anisotropy. For this model the soliton exist only if the number of bound magnons exceeds some threshold value $N_{\rm cr}$ depending on $\nu$ and the effective anisotropy constant $K_{\rm eff}$. We define soliton phase diagram as the dependence of threshold energies and bound magnons number on anisotropy constant. The phase boundary lines are monotonous for both $\nu=1$ and $\nu >2$, while the solitons with $\nu=2$ reveal peculiar nonmonotonous behavior, determining the transition regime from low to high topological charges. In particular, the soliton energy per topological charge (topological energy density) achieves a minimum neither for $\nu=1$ nor high charges, but rather for intermediate values $\nu=2$ or $\nu=3$.Comment: 8 pages, 4 figure

Magnetic vortex as a ground state for micron-scale antiferromagnetic samples

Here we consider micron-sized samples with any axisymmetric body shape and made with a canted antiferromagnet, like hematite or iron borate. We find that its ground state can be a magnetic vortex with a topologically non-trivial distribution of the sublattice magnetization $\vec{l}$ and planar coreless vortex-like structure for the net magnetization $\vec{M}$. For antiferromagnetic samples in the vortex state, in addition to low-frequency modes, we find high-frequency modes with frequencies over the range of hundreds of gigahertz, including a mode localized in a region of radius $\sim$ 30--40 nm near the vortex core.Comment: 20 pages, 1 figur

CLINICODIAGNOSTIC SIGNIFICANCE OF CILIARY AND BRAIN-DERIVED NEUROTROPHIC FACTORS IN CHILDREN WITH DIABETIC PERIPHERAL NEUROPATHY

Purpose: To investigate the role of ciliary and brain-derived neurotrophic factors in the development of diabetic peripheral neuropathy in children and teenagers with type-1 diabetes (T1D).Materials and methods: The article contains check-up results of 223 children and teenagers with type-1 diabetes. The authors evaluated clinical and functional parameters, which indicate the formation of diabetic peripheral neuropathy, and the content of ciliary and brain-derived neurotrophic factors in the blood serum in the observed patients.Results: The criteria of early diagnosis and prognosis of severe clinical course of diabetic peripheral neuropathy were developed.Summary: Statistically significant increase of the levels of ciliary and brain-derived neurotrophic factors rising in case of longterm decompensated course of disease in the blood serum was determined. Markers of early formation and prognostic indicators of severe clinical course of diabetic peripheral neuropathy in children and teenagers were revealed

Synthesis of phosphorylated piperazines

Heating 3-methyl-1,2-butadienyl phosphonates with piperazine leads to the formation of 2-piperazinyl-butenyl phosphonates containing the enamine functionality. From the reaction of piperazine with four equivalents of 1,2-butadienyl phosphonate a bis(phosphonate) is obtained, in which the piperazine bridge links two phosphorylbutene fragments. © 2013 Copyright Taylor and Francis Group, LLC

Large temperature dependence of the Casimir force at the metal-insulator transition

The dependence of the Casimir force on material properties is important for both future applications and to gain further insight on its fundamental aspects. Here we derive a general theory of the Casimir force for low-conducting compounds, or poor metals. For distances in the micrometer range, a large variety of such materials is described by universal equations containing a few parameters: the effective plasma frequency, dissipation rate of the free carriers, and electric permittivity in the infrared range. This theory can also describe inhomogeneous composite materials containing small regions with different conductivity. The Casimir force for mechanical systems involving samples made with compounds that have a metal-insulator transition shows an abrupt large temperature dependence of the Casimir force within the transition region, where metallic and dielectric phases coexist.Comment: 23 pages, 9 figure

Initial stage of formation of spontaneous invasive populations of garden lupine (lupinus polyphyllus lindl.) at the northern limit of its secondary distribution range in the veps forest nature park

A weed plant of the species Lupinus polyphyllus was found in settlements located on the territory of the natural park «Vepssky forest» of the Leningrad regio

Как нагрузить порожний вагонопоток

For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version).ABSTRACT The topic of increasing the efficiency of empty gondola cars is considered by the authors at the example of the West Siberian Railway. In the process of analyzing the situation, it was revealed that the main problems that have arisen with the multiplicity of owners of rolling stock are a consequence of the lack of a single mechanism for managing cargo flows and are at the interface of interaction with different structures, small and large, federal and local. It is necessary to build a new management system for empty car flows and regulate this system, in particular the roles of participants in the transportation process, including the operator. The technology of operation of companies-operators with a park of empty open cars, the order of normalization and planning of their approach to coal loading stations of the road are shown. Compliance with such technology allows to significantly increase the level of loading of cars, improve the fulfillment of delivery deadlines. Keywords: management, railway, empty car flow, operator, cargo owner, plurality of owners, transportation process. REFERENCES 1.Khusainov, F. I. Reform of the railway industry in Russia: the problems of unfinished liberalization: Monograph [Reforma zheleznodorozhnoj otrasli v Rossii: problemy nezavershjonnoj liberalizacii: Monografija].Moscow, Nauka publ., 2015, 272 p. 2.INFOLine on change of paradigm of the railway market: from surplus of car fleet to a balance with accelerated replacement of outdated rolling stock with innovative [INFOLine o smene paradigmy zheleznodorozhnogo rynka: ot proficita vagonnogo parka k balansu s uskorennym zameshheniem ustarevshego podvizhnogo sostava innovacionnym].http://infoline.spb.ru/m/news/102859/.Last accessed 27.07.2016. 3.Federal Law No.503-FZ dated December 31, 2014 [Federal’nyj zakon № 503-FZ ot 31.12.2014].Текст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).Тема повышения эффективности работы порожних полувагонов рассматривается авторами на примере Западно-Сибирской железной дороги. В процессе анализа ситуации выявлено, что основные проблемы, возникшие при множественности владельцев подвижного состава, являются следствием отсутствия единого механизма управления грузовыми потоками и находятся на стыке взаимодействия с разными структурами, мелкими и крупными, федеральными и местными. Необходимо построение новой системы управления порожними вагонопотоками и нормативного закрепления этой системы, в частности ролей участников перевозочного процесса, включая оператора. Показаны технология работы компаний-операторов с парком порожних полувагонов, порядок нормирования и планирования их подвода на углепогрузочные станции дороги. Соблюдение такой технологии позволяет значительно повысить уровень погрузки и маршрутизации вагонов, улучшить выполнение сроков доставки грузов

Polymorphism of alien Erigeron canadensis L. (Asteraceae) along the Trans-Siberian railway

The invasive species of North American origin, Erigeron canadensis L., found throughout the Trans-Siberian Railway has been set as a model object. This species grows directly on the railway track and on the adjacent slopes, therefore, its spreading is likely along the transport corridor, but not repeatedly from settlements located nearby the railwa

HISTORY AND MODERN MODEL Of NEPHROLOGY SERVICE IN MULTIPROfILE HOSPITAL

The purpose of the study was to present the stages of effective nephrological service forming and to evaluate the output results of the Regional Nephrological Center (RNC) as the unit of multidisciplinary hospital. Results and discussion. The nephrology service of State Novosibirsk Regional Clinical Hospital began to form in 1978 with the opening of nephrology hemodialysis and kidney transplantation departments. The RNC was established in 1993 on the base of a territorial register for patients with chronic renal failure. Currently, the RNC includes the department of nephrology, the register for patients with chronic kidney disease (CKD) of 3–5 stages, nephrological counseling office, offices for potential recipients of renal transplantation and for patients with transplanted kidney, the office of permanent outpatient peritoneal dialysis. As a result, the prevalence and structure of CKD 3–5 stages in the Novosibirsk region are comparable to those in Europe, the availability of the renal replacement therapy, including the number of patients with a functioning renal transplant exceeds the nationwide indicators. Conclusion. The model of the nephrological service of a multidisciplinary hospital provides accounting and dispensation of patients with CKD, increases the effectiveness of treatment, including methods of renal replacement therapy

Polymorphism of alien Erigeron canadensis L. (Asteraceae) along the Trans-Siberian railway

The invasive species of North American origin, Erigeron canadensis L., found throughout the Trans-Siberian Railway has been set as a model object. This species grows directly on the railway track and on the adjacent slopes, therefore, its spreading is likely along the transport corridor, but not repeatedly from settlements located nearby the railwa