Bifurcations and a chaos strip in states of long Josephson junctions

Stationary and nonstationary, in particular, chaotic states in long Josephson junctions are investigated. Bifurcation lines on the parametric bias current-external magnetic field plane are calculated. The chaos strip along the bifurcation line is observed. It is shown that transitions between stationary states are the transitions from metastable to stable states and that the thermodynamical Gibbs potential of these stable states may be larger than for some metastable states. The definition of a dynamical critical magnetic field characterizing the stability of the stationaryComment: 13 pages, 6 Postscript figures, uses revtex.st

Gaussian-SLAM: Photo-realistic Dense SLAM with Gaussian Splatting

We present a new dense simultaneous localization and mapping (SLAM) method that uses Gaussian splats as a scene representation. The new representation enables interactive-time reconstruction and photo-realistic rendering of real-world and synthetic scenes. We propose novel strategies for seeding and optimizing Gaussian splats to extend their use from multiview offline scenarios to sequential monocular RGBD input data setups. In addition, we extend Gaussian splats to encode geometry and experiment with tracking against this scene representation. Our method achieves state-of-the-art rendering quality on both real-world and synthetic datasets while being competitive in reconstruction performance and runtime

Experimental research of double-sided solar modules efficiency In the climatic conditions of central Kazakhstan

The article presents studies of double-sidedsolar modules in Kazakhstan. To conduct an experimental research of double-sided solar modules efficiency in the climatic conditions of Central Kazakhstan we have created an experimental solar power plant (SPP) located on the territory of Karaganda State Technical University. The solar power plant consists of four photovoltaic modules of KZ PV 270 M72 type and four photovoltaic modules of FSM-185D type. The rotary system was not used; solar panels are southward (directed to the south). The comparison was made with the solar power plantwithout orientation system which uses four photovoltaic modules of KZ PV 270 M72 type produced by Astana Solar LLP. The statistical analysis of information with an assessment of parameters of distribution and criteria for processing of results of scientific experiment is carried out. The correlation and regression analysis is performed. The least square method (coefficient calculation) is used in data processing. We have developed the computational model simulating the SPP by means of which the theoretical averaged values of energy amount generated in kWh/day have been obtained, and the actual values have been received by in-use measurements of SPP parameters within a year. The results of this work showed that the use of double-sided solar modules in Kazakhstan is very promising and can be a decisive factor for their widespread use with the tendency to lower prices

Research of mechanical stress at tension of quartz optical fiber (QOF)

The article presents the results of a study of the process of occurrence of mechanical stress and strain during stretching of a quartz optical fiber. The analysis and review of the current state of development of fiber-optic conductors is performed. The problems of occurrence of microcracks in the body of optical fibers during mechanical loading during operation are considered. In the process of winding optical fibers and further operation, cracks occur. The conducted research allows us to solve an important production problem related to increasing the strength of optical fibers and reducing the number of microcracks. The object of scientific research is quartz optical fiber of the G652 standard, used for the production of fiber-optic cables. For optical fibers, the greatest danger is the stretching, which is observed when rewinding the fiber, during its cabling, during the laying and operation of the optical cable. It was found that the mechanical tensile strength of G652 optical fiber was from 4 482 to 4 808 MPa, and the number of cracks and their parameters affect the tensile strength of the fiber

Using optical fibers (OF) to control the stress-strain state of steel structures subject to fatigue failure

The article presents the results related to developing and practical testing the method of monitoring the stress strain state of steel structures of mine hoisting machines. Certain positive properties of optical fibers make it possible to use them for measuring the stress-strain state of steel structures. An optical fiber of the ITU-T G.652.D standard is used as a sensor. The analysis and review of the current state of development of fiber-optic conductors is performed. The proposed method of non-destructive testing the stress-strain state of metal structures is capable of providing continuous measurements in real time. The proposed method is universal and suitable for monitoring the stress-strain state of any metal structures subject to fatigue failure

Static Solitons of the Sine-Gordon Equation and Equilibrium Vortex Structure in Josephson Junctions

The problem of vortex structure in a single Josephson junction in an external magnetic field, in the absence of transport currents, is reconsidered from a new mathematical point of view. In particular, we derive a complete set of exact analytical solutions representing all the stationary points (minima and saddle-points) of the relevant Gibbs free-energy functional. The type of these solutions is determined by explicit evaluation of the second variation of the Gibbs free-energy functional. The stable (physical) solutions minimizing the Gibbs free-energy functional form an infinite set and are labelled by a topological number Nv=0,1,2,... Mathematically, they can be interpreted as nontrivial ''vacuum'' (Nv=0) and static topological solitons (Nv=1,2,...) of the sine-Gordon equation for the phase difference in a finite spatial interval: solutions of this kind were not considered in previous literature. Physically, they represent the Meissner state (Nv=0) and Josephson vortices (Nv=1,2,...). Major properties of the new physical solutions are thoroughly discussed. An exact, closed-form analytical expression for the Gibbs free energy is derived and analyzed numerically. Unstable (saddle-point) solutions are also classified and discussed.Comment: 17 pages, 4 Postscript figure

Молекулярные особенности гастроинтестинальных стромальных опухолей «дикого типа» (KIT/PDGFRA WT)

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. Their main features are the expression of CD117 (KIT) and mutations of KIT or PDGFRA in 85 % of patients. however, 10–15 % of adult GIST and 85 % of pediatric GIST do not have KIT/PDGFRA mutations (KIT/PDGFRA WT GIST or “wild-type” GIST). The prognosis and clinical course of these tumors and GIST with KIT/PDGFRA mutations differ. “Wild-type” GIST are quite heterogeneous group of tumors in terms of clinical phenotype, genetic etiology, and molecular pathways. Gastrointestinal stromal tumors are divided into SDH-deficient and SDH-competent based on the succinate dehydrogenase (SDH) complex. SDH-deficient GIST occur predominantly in children and young patients  with Carney–Stratakis syndrome and Carney triad; there are also sporadic tumors. More than half of SDH-deficient GIST contain mutations in SDHA, SDHB, SDHD or SDHC, while the rest are caused by hypermethylation of the SDHC promoter. SDH-competent “wild-type” GIST include tumors with BRAF, RAS, or NF1 mutations that activate the RAS-RAF-MAPK pathway and KIT/PDGFRA/SDH/RAS-P WT GIST subtype or “quadruple wild type” GIST. The genomic profiles of these tumors and GIST with KIT/PDGFRA mutation or SDH deficiency differ significantly. One of the features of “quadruple wild type” GIST is activation of the FGFR (fibroblast growth factor receptors) signaling pathway due to chimeric FGFR, FGFR mutations, or overexpression of FGF (fibroblast growth factor). Another feature is chimeric genes containing fragments of NTRK, BRAF, FGFR and other genes that behave as oncogene drivers. In “quadruple wild-type” GIST the somatic mutations in TP53, MAX, MEN1, CTNND2, CHD4, ARIDIA and other genes were revealed as well as in the cell cycle genes RB1, CDK4, CDKN1B. There is no specific treatment for patients with “wild-type” GIST; the choice of drug is determined by the genetic disorder. There is a need to improve our understanding of the molecular mechanisms underlying the different GIST subtypes to develop more effective therapeutic approaches.Гастроинтестинальные стромальные опухоли (ГИСО) – наиболее распространенные мезенхимальные опухоли желудочно-кишечного тракта. Их основными признаками являются экспрессия cD117 (KIT) и мутации в генах KIT или PDGFRA у 85 % пациентов. Однако 10–15 % ГИСО взрослых и 85 % ГИСО детей не имеют мутаций KIT/PDGFRA (ГИСО KIT/PDGFRA WT, или ГИСО «дикого типа»). Прогноз и клиническое течение этих опухолей и ГИСО с мутациями KIT/PDGFRA различаются. Гастроинтестинальные стромальные опухоли «дикого типа» довольно гетерогенная группа опухолей по клиническому фенотипу, генетической этиологии и по молекулярным путям. Гастроинтестинальные стромальные опухоли разделяют на SDH-дефицитные и SDH-компетентные по комплексу сукцинатдегидрогеназы (SDH). SDH-дефицитные ГИСО встречаются преимущественно у детей и молодых пациентов с синдромом Карни–Стратакиса и триадой Карни, есть и спорадические опухоли. Более 50 % SDH-дефицитных ГИСО содержат мутации в генах SDHA, SDHB, SDHD, SDHC, а остальные вызваны гиперметилированием промотора SDHC. SDH-компетентные ГИСО «дикого типа» включают опухоли с мутациями  BRAF, RAS или NF1, которые активируют RAS-RAF-MAPK-путь и подтип ГИСО KIT/PDGFRA/SDH/RAS-P WT, или ГИСО «четырежды дикого типа». Профили генома этих опухолей и ГИСО с мутацией KIT/PDGFRA или дефицитом SDH значительно различаются. Одной из особенностей ГИСО «четырежды дикого типа» является активация  FGFR-сигнального пути (FGFR – рецепторы фактора роста фибробластов) из-за химерных генов FGFR, мутаций FGFR или гиперэкспрессии фактора роста фибробластов (FGF). Еще одной особенностью являются химерные гены, содержащие фрагменты генов NTRK, BRAF,  FGFR и других, которые ведут себя как онкогены-драйверы. В ГИСО «четырежды дикого типа» выявлены соматические мутации генов TP53, MAX, MEN1, CTNND2, CHD4, ARIDIA  и других, а также генов клеточного цикла RB1, CDK4, CDKN1B. Специфического лечения для пациентов с ГИСО «дикого типа» не существует, выбор препарата обусловлен генетическим нарушением. Необходимо совершенствовать понимание молекулярных механизмов, лежащих в основе различных подтипов ГИСО, для разработки более эффективных терапевтических подходов

Клинический случай: сочетание иммуноопосредованной тромбоцитопении и миокардита на фоне лечения немелкоклеточного рака легкого ингибиторами контрольных точек

Immune-related adverse events (irAE) present a unique challenge in modern oncology. In patient treated with immune checkpoint inhibitors (anti-PD-1, anti-CTLA-4, anti-PD-L1) for solid tumors irAEs rate ranges from 60 to 85 % [1]. irAEs lead to complete treatment discontinuation in approximately 40 % of patients [2]. The most common irAEs are endocrinopathies (up to 10 %), pneumonitis (5 to 10 %), autoimmune hepatitis (up to 20 %), colitis (up to 30 %), and skin toxicity (up to 50 %) [3]. Other forms of adverse events, such as hematologic and cardiovascular toxicities, are very rarely reported. We present a clinical case of two rare adverse events in a patient treated with pembrolizumab for PD-L1‑positive advanced non-small cell lung cancer.Иммуноопосредованные нежелательные явления (иНЯ) являются актуальной проблемой современной онкологии. При лечении пациентов с солидными опухолями ингибиторами контрольных точек (анти-PD-1, анти-CTLA-4, PD-L1) частота иНЯ достигает 60–85 % [1]. Примерно в 40 % случаев иНЯ требуют полной отмены терапии [2]. К наиболее частым осложнениям этого типа относятся эндокринопатии (до 10 %), пульмониты (5–10 %), аутоимунные гепатиты (до 20 %), колиты (до 30 %), кожная токсичность (до 50 %) [3]. Другие формы нежелательных явлений, такие как гематологическая и кардиоваскулярная токсичность, встречаются крайне редко. Мы описываем клинический случай развития двух редких осложнений у пациента, получающего терапию пембролизумабом по поводу распространенной стадии PD-L1‑позитивного немелкоклеточного рака легкого