Selective deposition of polycrystalline diamond films using photolithography with addition of nanodiamonds as nucleation centers

A new method of selective deposition of polycrystalline diamond has been developed and studied. The diamond coatings with a complex, predetermined geometry and resolution up to 5 [mu]m were obtained. A high density of polycrystallites in the coating area was reached (up to 32·10{7} pcs/cm{2}). The uniformity of the film reached 100%, and the degree of the surface contamination by parasitic crystals did not exceed 2%. The technology was based on the application of the standard photolithography with an addition of nanodiamond suspension into the photoresist that provided the creation of the centers of further nucleation in the areas which require further overgrowth. The films were deposited onto monocrystalline silicon substrates using the method of "hot filaments" in the CVD reactor. The properties of the coating and the impact of the nanodiamond suspension concentration in the photoresist were also studied. The potential use of the given method includes a high resolution, technological efficiency, and low labor costs compared to the standard methods (laser treatment, chemical etching in aggressive environments)

Special features of the surface layer structure of ferritic-martensitic EP-823-Sh steel after prolonged exposure to the flowing lead at 630 °C under low oxygen concentration

The microstructure, the phase and elemental compositions of the surface and near-surface layers of the EP-823-Sh reactor 12 % chromium ferritic-martensitic steel after holding in an oxygen-containing (C[o] = (4–8) × 10−7 wt. %) molten lead flow at 630 °C for 2500 h are investigated. As a result of the liquid lead interaction with the steel samples, an oxide film from 250 nm to 18 μm is formed on their surfaces. It is a layer of Fe-Cr spinel enriched in Si and Mn. An internal oxidation zone of steel with a thickness of 4–10 μm is found under the scale layer. In the internal oxidation zone, both inside the matrix grains and along their boundaries, oxide particles (Cr, Si, Mn)2 O3 and Fe3 O4 with sizes up to 50 nm are observed. Below this zone, a matrix layer depleted in chromium (with a thickness of ≤ 15 μm) is located. The features of the oxidation zone structure are discussed, the role of alloying elements is determined (identified and validated), and a possible mechanism for the formation of such a zone is proposed

A case report of recurrent acute ischemic strokes in a young patient with Rendu-Osler-Weber disease

Rendu-Osler-Weber disease is a rare inherited disease of the vasculature, characterized by the development of multiple telangiectasias of the skin and mucous membranes, as well as hemorrhagic syndrome of various localization. We present a case report of recurrent acute ischemic strokes in a young patient with Rendu-Osler-Weber disease. In the first part of the article, literature data on the incidence, etiology, pathogenesis, features of clinical manifestations of hereditary hemorrhagic telangiectasia, modern methods of diagnosis and treatment are presented. In the second part of the article, a rare case of recurrent acute ischemic strokes in a young patient with Rendu-Osler-Weber disease, caused by a paradoxical embolism due to pulmonary arteriovenous malformation was demonstrated. The chest CT detected a pulmonary arteriovenous malformation. The data of medical, including anamnesis, a description of the objective and neurological status, the results of laboratory and instrumental methods of examination are presented. The patient was recommended angiopulmonography, during which the pulmonary arteriovenous malformation was successfully embolized. This case indicates the need for targeted examination and monitoring of patients with hereditary hemorrhagic telangiectasia. For the purpose of early detection of vascular malformations in patients with Rendu-Osler-Weber disease and the timely administration of therapy to prevent possible serious cerebrovascular complications, we recommend performing the chest CT.Болезнь Рандю-Ослера-Вебера или наследственная геморрагическая телеангиэктазия представляет собой редкое наследственное заболевание сосудистой системы, характеризующееся развитием множественных телеангиэктазий кожи и слизистых оболочек, а также геморрагическим синдромом различной локализации. Мы представляем клинический разбор случая развития повторных инфарктов головного мозга у молодого пациента с болезнью Рандю-Ослера-Вебера. В первой части публикации приводятся литературные данные о частоте встречаемости, этиологии, патогенезе, особенностях клинических проявлений наследственной геморрагической телеангиэктазии, современных методах диагностики и лечения. Во второй части продемонстрирован редкий случай развития повторных инфарктов головного мозга у молодого пациента с болезнью Рандю-Ослера-Вебера, причиной которых явилась парадоксальная эмболия из легочной артериовенозной мальформации, обнаруженной у пациента при проведении КТ-ангиографии сосудов легких. Представлены данные анамнеза жизни и заболевания пациента, описание объективного и неврологического статуса, результаты лабораторных и инструментальных методов обследований. Пациенту было рекомендована ангиопульмонография, в ходе которой легочная артериовенозная мальформация была успешно эмболизирована. данный случай указывает на необходимость тщательного обследования и наблюдения за пациентами с наследственной геморрагической телеангиэктазией. В целях раннего выявления сосудистых мальформаций у пациентов с болезнью Рандю-Ослера-Вебера и своевременного назначения терапии для предотвращения возможных серьёзных цереброваскулярных осложнений рекомендовано выполнение КТ-ангиографии легких

The peculiarities of cross-correlation between two secondary precursors - radon and magnetic field variations, induced by stress transfer changes

A model of precursor manifestation mechanisms, stimulated by tectonic activity and some peculiarities of observer strategy, whose main task is the effective measurement of precursors in the spatial area of their occurrence on the Earth's daylight, are considered. In particular, the applicability of Dobrovolsky's approximation is analyzed, when an unperturbed medium (characterized by the simple shear state) and the area of tectonic activity (local inhomogeneity caused by the change only of shear modulus) are linearly elastic, and perturbation, in particular, surface displacement is calculated as a difference of the solutions of two independent static problems of the theory of elasticity with the same boundary condition on the surface. Within the framework of this approximation a formula for the spatial distribution (of first component) of magnetic field variations caused by piezomagnetic effect in the case of perturbed regular medium, which is in simple shear state is derived. Cogent arguments in favor of linear dependence between the radon spatial distribution and conditional deformation are obtained. Changes in magnetic field strength and radon concentrations were measured along a tectonomagnetic profile of the total length of 11 km in the surroundings of the "Academician Vernadsky" Station on the Antarctic Peninsula (W 64{\deg}16', S 65{\deg}15'). Results showed a positive correlation between the annual surface radon concentration and annual changes of magnetic field relative to a base point, and also the good coincidence with theoretical calculation.Comment: 27 pages, 11 figures, 3 tables (a substantially revised and extended edition; v3 -- some analysis of recent publications added

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

Структурные и физико-химические преобразования перикардиальных имплантатов, модифицированных эпоксидной смолой

Bovine pericardium samples modified with ethylene glycol diglycidyl ether, designed for surgical correction of congenital heart defects and large blood vessels, were studied by scanning electron microscopy, X-ray diffraction, IR spectroscopy, and differential thermal analysis. It was found that the initial samples of pericardium, before implantation, contain sites of disorganization of the collagen matrix, fragile fracture of collagen fibrils and destruction of the interstitial membranes promoting the penetration of immunocytes into the deep layers of the pericardium. Ossifying calcification with amorphized hydroxyapatite deposition and bone tissue formation as well as multiple erosions and hypertrophic proliferation in the endothelial membrane were detected in the implantation pericardium samples.Методами сканирующей электронной микроскопии, рентгенофазового анализа, ИК-спектроскопии, дифференциально-термического анализа изучены образцы бычьих перикардов, модифицированные диглицедиловым эфиром этиленгликоля, предназначенные для хирургической коррекции врожденных пороков сердца и крупных кровеносных сосудов. В исходных образцах перикардов до имплантации обнаружены дезорганизация коллагеновой матрицы, хрупкий перелом коллагеновых фибрилл и разрушение структуры интерстициальных мембран, способствующих проникновению иммуноцитов в глубокие слои перикарда. В имплантированных образцах перикардов выявлены оссифицирующий кальциноз с отложением аморфизированного гидроксиапатита и формированием костной ткани, а также множественные эрозии и гипертрофические разрастания в эндотелиальной мембране

Condensation transition in joint large deviations of linear statistics

Real space condensation is known to occur in stochastic models of mass transport in the regime in which the globally conserved mass density is greater than a critical value. It has been shown within models with factorised stationary states that the condensation can be understood in terms of sums of independent and identically distributed random variables: these exhibit condensation when they are conditioned to a large deviation of their sum. It is well understood that the condensation, whereby one of the random variables contributes a finite fraction to the sum, occurs only if the underlying probability distribution (modulo exponential) is heavy-tailed, i.e. decaying slower than exponential. Here we study a similar phenomenon in which condensation is exhibited for non-heavy-tailed distributions, provided random variables are additionally conditioned on a large deviation of certain linear statistics. We provide a detailed theoretical analysis explaining the phenomenon, which is supported by Monte Carlo simulations (for the case where the additional constraint is the sample variance) and demonstrated in several physical systems. Our results suggest that the condensation is a generic phenomenon that pertains to both typical and rare events.Comment: 30 pages, 4 figures (minor revision