Vortex soliton tori with multiple nested phase singularities in dissipative media

We show the existence of stable two- and three-dimensional vortex solitons carrying multiple, spatially separated, single-charge topological dislocations nested around a vortex-ring core. Such new nonlinear states are supported by elliptical gain landscapes in focusing nonlinear media with two-photon absorption. The separation between the phase dislocations is dictated mostly by the geometry of gain landscape and it only slightly changes upon variation of the gain or absorption strength.Comment: 17 pages, 5 figures, to appear in Physical Review

Topological light bullets supported by spatio-temporal gain

We reveal that the competition between diffraction, cubic nonlinearity, two-photon absorption, and gain localized in both space and time results in arrest of collapse, suppression of azimuthal modula-tion instabilities for spatiotemporal wavepackets, and formation of stable three-dimensional light bul-lets. We show that Gaussian spatiotemporal gain landscapes support bright, fundamental light bullets, while gain landscapes featuring a ring-like spatial and a Gaussian temporal shapes may support stable vortex bullets carrying topological phase dislocations.Comment: 19 pages, 5 figures, to appear in Physical Review

Digital storytelling as a presentation technologylarge data sets

В статье рассматривается феномен цифрового сторителлинга как современной технологии представления больших массивов данных. Описываются структурная и содержательная специфика мультимедийных историй.The article deals with the phenomenon of digital storytelling as a modern technology of representation of large data sets. The structural and substantial specificity of multimedia stories is described

Current status of the problem of cardiovascular diseases in the Nizhny Novgorod region: possible ways to reduce mortality

The article considers the urgent problem of combating cardiovascular diseases (CVDs) in the Nizhny Novgorod region, including the high prevalence of CVDs and the timely identification of risk factors. The changes in mortality from all and individual causes was analyzed. Attention was paid to the negative impact of the coronavirus disease 2019 (COVID-19) pandemic on the health of people suffering from noncommunicable diseases. We also described the necessity to improve healthcare efficiency for CVD patients by improving the complex of managerial and preventive measures

Alternating Hemiplegia of Childhood Diagnostic Difficulties (clinical case)

This article describes clinical cases of a 9-month old child with a rare hereditary disease - alternating hemiplegia of childhood. Difficulties of differential diagnosis between this disease and focal epilepsy are shown.В статье представлено клиническое наблюдение ребенка в возрасте девяти месяцев с редким наследственным заболеванием - альтернирующей гемиплегией детского возраста. Показана сложность дифференциальной диагностики данного заболевания с фокальной эпилепсией

On strong causal binomial approximation for stochastic processes

This paper considers binomial approximation of continuous time stochastic processes. It is shown that, under some mild integrability conditions, a process can be approximated in mean square sense and in other strong metrics by binomial processes, i.e., by processes with fixed size binary increments at sampling points. Moreover, this approximation can be causal, i.e., at every time it requires only past historical values of the underlying process. In addition, possibility of approximation of solutions of stochastic differential equations by solutions of ordinary equations with binary noise is established. Some consequences for the financial modelling and options pricing models are discussed

Catalytic sulfation of betulin with sulfamic acid : experiment and DFT calculation

Betulin is an important triterpenoid substance isolated from birch bark, which, together with its sulfates, exhibits important bioactive properties. We report on a newly developed method of betulin sulfation with sulfamic acid in pyridine in the presence of an Amberlyst(®)15 solid acid catalyst. It has been shown that this catalyst remains stable when being repeatedly (up to four cycles) used and ensures obtaining of sulfated betulin with a sulfur content of ~10%. The introduction of the sulfate group into the betulin molecule has been proven by Fourier-transform infrared, ultraviolet-visible, and nuclear magnetic resonance spectroscopy. The Fourier-transform infrared (FTIR) spectra contain absorption bands at 1249 and 835–841 cm(−1); in the UV spectra, the peak intensity decreases; and, in the nuclear magnetic resonance (NMR) spectra, of betulin disulfate, carbons С3 and С28 are completely shifted to the weak-field region (to 88.21 and 67.32 ppm, respectively) with respect to betulin. Using the potentiometric titration method, the product of acidity constants K(1) and K(2) of a solution of the betulin disulfate H(+) form has been found to be 3.86 × 10(–6) ± 0.004. It has been demonstrated by the thermal analysis that betulin and the betulin disulfate sodium salt are stable at temperatures of up to 240 and 220 °C, respectively. The density functional theory method has been used to obtain data on the most stable conformations, molecular electrostatic potential, frontier molecular orbitals, and mulliken atomic charges of betulin and betulin disulfate and to calculate the spectral characteristics of initial and sulfated betulin, which agree well with the experimental data

Early epileptic encephalopathy associated with SCN2A mutation (clinical case)

Molecular genetic research is becoming an integral part in the diagnosis of epilepsy, especially those cases, characterized by a severe run and not responsive to standard antiepileptic therapy. The case of a patient with epilepsy due to a previously unknown heterozygous mutation in the 11 exon of the SCN2A gene is given. The main clinical manifestations were drug-resistant epileptic seizures and dementia. The diseases debuted at the age of 2 years 9 months with febrile seizures. Spontaneous complex partial epileptic seizures joined within a month. The appointment of glucocorticoids as well as anticonvulsants in mono- and polytherapy, was not effective. After 3 months, along with seizures frequency increase up to status epilepticus, the psychomotor development regressed with the loss of previously acquired skills. Dynamic observation up to the age of 10 years revealed signs of epileptic encephalopathy in the form of dementia: the patient does not walk without assistance, does not speak and does not understand spoken speech, neatness and self-care skills are not formed.Молекулярно-генетическое исследование становится неотъемлемым звеном в диагностике эпилепсий, особенно характеризующихся тяжелым течением, не поддающихся стандартной антизпилептической терапии. Приведен случай пациентки с зпилепсией, обусловленной ранее не описанной гетерозиготной мутацией в 11 экзоне гена SCN2A. Основными клиническими проявлениями являлись фармакорезистентные эпилептические припадки и деменция. Заболевание дебютировало в возрасте 2 лет 9 месяцев с фебрильных судорог. В течение месяца присоединились спонтанные комплексные парциальные эпилептические припадки. Назначение антиконвульсантов в моно - и политерапии, а также глюкокортикоидов было не эффективно. Через 3 месяца, на фоне учащения припадков вплоть до эпилептического статуса, возник регресс психомоторного развития с утратой ранее приобретенных навыков. При динамическом наблюдении до возраста 10 лет выявлялись признаки эпилептической энцефалопатии в виде деменции: самостоятельно не ходит, не говорит и обращенную речь не понимает, навыки опрятности и самообслуживания не сформированы