57 research outputs found
Transcatheter transfemoral aortic valve replacement in a patient with acromegaly and severe left ventricular myocardial hypertrophy. Case report
Main causes of secondary hypertrophic cardiomyopathy include acromegalic cardiomyopathy. Heart damage in patients with the acromegaly is mediated both by the direct action of growth hormone and insulin-like growth factor-1, and increased deposition of collagen and lymphomononuclear cells in the myocardium, which leads to architectural changes, disturbances in fluid and electrolyte balance, severe left ventricular myocardial hypertrophy, diastolic and systolic left ventricular dysfunction and chronic heart failure. This article presents the world's first described observation demonstrating the possibility of successful transfemoral aortic valve repair to a comorbid patient with severe aortic stenosis according to the potential risks caused by the active form of the acromegaly
Transcatheter mitral valve edge-to-edge repair in patients with severe mitral regurgitation: data from the MitraClip Russia Trial
Aim. To study the immediate and short-term outcomes of transcatheter mitral valve edge-to-edge repair with the MitraClip NT in patients with severe mitral regurgitation as part of the MitraClip Russia prospective single-center study.Material and methods. The study included 16 patients (men, 10; women, 6) with mean age of 70,1±2,1 years (mean Euroscore II, 6,90±5,56%; STS, 6,33±3,94%). Immediate technical success was defined as successful access, delivery, and removal of the device, and adequate placing the clip(s) to reduce the mitral regurgitation to grade 2 or below without the need for device- or procedure-related reintervention.Results. Immediate technical success was achieved in all patients. The average number of implanted clips per 1 patient was 1,7. In 1 patient (6,3%), a clip was attached to one mitral leaflet, which required an non-scheduled implantation of a second clip. In hospital mortality was 6,3%: a 92-year-old patient on the 3rd day after the operation had a sudden cardiac arrest followed by coma, hemispheric ischemic stroke and death on the 6th day. An autopsy revealed an iatrogenic atrial septal defect. Echocardiography performed on the 10th and 30th day after surgery showed a decrease in mitral regurgitation grade in 15 patients, while grade 3 residual mitral regurgitation did not reveal in any patient.Conclusion. Transcatheter mitral valve edge-to-edge repair with the MitraClip is a minimally invasive method for treating severe symptomatic mitral regurgitation (degenerative and functional). The results demonstrate high immediate efficacy and an acceptable safety profile in high surgical risk patients. Based on the analysis of death causes, the authors conclude that it is necessary to include initial pulmonary hypertension above 75 mm Hg as a relative contraindication to this procedure. The study limitations are the small sample size and short follow-up period
ГЕОДИНАМИЧЕСКАЯ АКТИВНОСТЬ НОВЕЙШИХ СТРУКТУР И ПОЛЯ ТЕКТОНИЧЕСКИХ НАПРЯЖЕНИЙ СЕВЕРО-ВОСТОКА АЗИИ
Based on the analysis of changes in the stress-strain state of the crust at the boundary of the Eurasian and North American tectonic plates, we develop a dynamic model of the main seismogenerating structures inNortheast Asia. We have established a regularity in changes of geodynamic regimes within the interplate boundary between the Kolyma-Chukotka crustal plate and the Eurasian, North American and Pacific tectonic plates: spreading in the Gakkel Ridge area; rifting in the Laptev Sea shelf; a mixture of tectonic stress types in the Kharaulakh segment; transpression in the Chersky seismotectonic zone, in the segment from the Komandor to the Aleutian Islands, and in the Koryak segment; and crustal stretching in the Chukotka segment.Анализ изменений напряженно-деформированного состояния земной коры, проведенный вдоль границы Евразийской и Североамериканской литосферных плит, позволил обосновать динамическую модель главных сейсмогенерирующих структур территории северо-востока Азии. В пределах единой межплитной границы, отделяющей Колымо-Чукотскую коровую плиту от Евразийской, Североамериканской и Тихоокеанской литосферных плит, наблюдается закономерная смена геодинамических режимов: спрединг хребта Гаккеля; рифтогенез на шельфе моря Лаптевых; смешанное поле тектонических напряжений в Хараулахском сегменте; транспрессия в сейсмотектонической зоне Черского, на участке от Командорских до Алеутских островов и в Корякском сегменте; растяжение в Чукотском сегменте
ПРОВЕДЕНИЕ ДЕТАЛЬНЫХ АЭРОГЕОФИЗИЧЕСКИХ РАБОТ В СЛОЖНОДИСЛОЦИРОВАННЫХ КОМПЛЕКСАХ СУТАМСКОГО ТЕРРЕЙНА (АЛДАНСКИЙ ЩИТ) ПРИ ИЗУЧЕНИИ ЖЕЛЕЗОРУДНЫХ МЕСТОРОЖДЕНИЙ
Magnetic exploration is the most informational and economical method of prospecting and exploration of iron-ore deposits. In rough-terrain and remote areas without any infrastructure, problems associated with ground-based methods can be avoided by using modern unmanned technologies that allow conducting geophysical surveys in a more efficient way. An unmanned aeromagnetic survey complex (aerial vehicle, UAV) Geoscan 401 was used to assess the possibility of using UAVs for aeromagnetic surveying of iron-ore deposits. Our experimental study was conducted in the well-studied area of the largest iron-ore deposit of South Yakutia. The UAV capacities were confirmed by comparing the aeromagnetic survey data with the available data obtained by ground magnetic exploration of the study area. By analysing magnetic fields, we established that the anomalies detected by the ground and aeromagnetic surveys were fully identical. Furthermore, a weak anomaly was discovered in the northeastern part of the study area (it was not reflected in the magnetic field from the ground survey data). Recalculation of the vertical gradient of the magnetic field shows that the anomaly is caused by a blind ore body. Its upper edge is located at a depth of 200–250 m from the day surface. In calculations for a data array without gradient intervals, a mean square error (MSE) amounts to 1.01 nT. An absolute error in the heights of the working and control flights did not exceed 1.5 m. Both the preliminary and control measurements were performed very efficiently. Profiles for UAV surveys were spaced by 100 m. A 1.0 km2 site was covered by one flight within approximately 20 minutes. The Geoskan-401 UAV is useful for obtaining orthophotos, topographic maps and 3D models of the surveyed territory as required for further studies consistent with the magnetic surveys. The aeromagnetic surveys were followed by trenching to verify the newly discovered anomalies. Based on the results of this experimental study, the forecast resources of the Sutam deposit should be increased by almost 250–350 million tons, i.e. plus 15 % to the previously explored and approved reserves of the Sutam field.Магниторазведка представляет собой наиболее информационный и экономичный метод при поиске и разведке железорудных месторождений. Избежать проблем с постановкой наземных методов на труднопроходимых и удаленных от инфраструктуры территориях, повысить скорость их изучения позволяют беспилотные технологии. Для оценки возможности применения беспилотной аэромагнитной съемки на железорудных объектах Якутии были выполнены опытно-методические работы на уже хорошо изученном ранее крупнейшем железорудном месторождении Южной Якутии с использованием беспилотного комплекса «Геоскан 401». Данный подход позволил установить работоспособность полетного комплекса, сопоставив имеющиеся данные наземных магниторазведочных работ с данными аэромагниторазведочных работ. Анализ магнитных полей показал полную идентичность полученных аномалий наземной и аэромагнитной съемки. Более того, на северо-востоке участка была выделена слабая аномалия, которая не отражена в магнитном поле наземной съемки. Пересчет вертикального градиента магнитного поля позволил определить, что аномалия обусловлена слепым рудным телом, верхняя кромка которого располагается на глубине 200–250 м от дневной поверхности. Среднеквадратическая погрешность, вычисленная для массива данных без градиентных интервалов, составила 1.01 нТл. Абсолютная погрешность высоты основного и контрольного полетов не превышает 1.5 м. По результатам рабочих и контрольных замеров отмечается высокая воспроизводимость измерений. За один полет по сети профилей с шагом 100 м был изучен участок площадью 1 км2. Полетное время составило немногим более 20 мин. Дополнением работы с полетным комплексом «Геоскан-401» стала возможность съемки ортофотопланов, топопланов, трехмерных моделей местности – в зависимости от потребностей – последовательно с выполнением магниторазведочных работ. Согласно результатам аэромагниторазведочных работ и последующей заверки полученных новых аномалий горно-вскрышными работами в виде канав и траншей, прирост прогнозных ресурсов Сутамской площади составил примерно 250–350 млн т – 15 % от уже опоискованных ранее и утвержденных запасов Сутамского месторождения
КАРТА СЕЙСМОТЕКТОНИКИ ВОСТОЧНОЙ СИБИРИ
The paper reviews goals and objectives, stages and the content of seismotectonic studies conducted in Eastern Siberia. Such studies are based on a comprehensive analysis of geological and geophysical data and provide for establishing whether the local earthquakes are of tectonic origin and revealing their relationships with recent geodynamic processes in the area under study. Seismic hazard assessment and evaluation of tectonic processes are the two major, closely interrelated aspects of seismotectonic studies. The latter are generally conducted in combination with seismic studies prior to the stage of detailed seismic zonation (DSZ) which is followed by seismic micro-zonation (SMZ). In three stages of seismotectonic studies, we analyse specific geological structures, reveal the regional dynamics of seismotectonic processes, clarify details of potential seismic hazard locations and identify sites of the potential instantaneous deformation of the crust which may take place due to active faulting. Based on results of the long-term studies conducted by the authors, a seismotectonic map of Eastern Siberia is compiled. The paper briefly reviews the methods of mapping and refers to data on active faults and neotectonic structures revealed in the area under study, which are closely related to regional earthquake sources.В статье рассматриваются задачи, стадийность проведения и содержание сейсмотектонических исследований как отдельного вида анализа комплексных геолого-геофизических материалов, используемых для установления тектонической природы проявлений местных землетрясений и их связи с современными геодинамическими процессами, протекающими на исследуемой территории. В задачи сейсмотектонических исследований входят два тесно взаимосвязанных направления: оценка опасности сейсмических явлений и оценка тектонических процессов. Сейсмотектонические исследования, совместно с сейсмологическими, всегда предваряют стадию детального сейсмического районирования (ДСР) и в последующем – сейсмического микрорайонирования (СМР). Сами сейсмотектонические исследования проводятся в три этапа и позволяют на региональном уровне изучения конкретных геологических структур определить геодинамику сейсмотектонических процессов, провести детальную локализацию сейсмической опасности и выявить места возможного проявления мгновенных деформаций земной поверхности, связанных с активными разломами. Результаты многолетних авторских исследований обобщены в карте сейсмотектоники Восточной Сибири, для которой дается краткое описание принципов и методов ее построения, приводятся наглядные примеры выделенных активных разломов и неотектонических структур, тесно связанных с региональными эпицентрами землетрясений
The impact of Grey Heron (Ardea cinerea L.) colony on soil biogeochemistry and vegetation: a natural long-term in situ experiment in a planted pine forest
Increased anthropogenic pressure including intensification of agricultural activities leads to long-term decline of natural biotopes, with planted forests often considered as promising compensatory response, although reduced biodiversity and ecosystem stability represent their common drawbacks. Here we present a complex investigation of the impact of a large Grey Heron (Ardea cinerea L.) colony on soil biogeochemistry and vegetation in a planted Scots pine forest representing a natural in situ experiment on an engineered ecosystem. After settling around 2006, the colony expanded for 15 years, leading to the intensive deposition of nutrients with feces, food remains and feather thereby considerably altering the local soil biogeochemistry. Thus, lower pH levels around 4.5, 10- and 2-fold higher concentrations of phosphorous and nitrogen, as well as 1.2-fold discrepancies in K, Li, Mn, Zn and Co., respectively, compared to the surrounding control forest area could be observed. Unaltered total organic carbon (Corg) suggests repressed vegetation, as also reflected in the vegetation indices obtained by remote sensing. Moreover, reduced soil microbial diversity with considerable alternations in the relative abundance of Proteobacteria, Firmicutes, Acidobacteriota, Actinobacteriota, Verrucomicrobiota, Gemmatimonadota, Chujaibacter, Rhodanobacter, and Bacillus has been detected. The above alterations to the ecosystem also affected climate stress resilience of the trees indicated by their limited recovery from the major 2010 drought stress, in marked contrast to the surrounding forest (p = 3∙10−5). The complex interplay between geographical, geochemical, microbiological and dendrological characteristics, as well as their manifestation in the vegetation indices is explicitly reflected in the Bayesian network model. Using the Bayesian inference approach, we have confirmed the predictability of biodiversity patterns and trees growth dynamics given the concentrations of keynote soil biogeochemical alternations with correlations R > 0.8 between observations and predictions, indicating the capability of risk assessment that could be further employed for an informed forest management
SEISMOGEOLOGY OF VERKHNEKERULEN BASIN (KHENTEI, NORTHERN MONGOLIA)
The paper presents results of seismogeological studies of active faults bordering the Upper Kerulen basin, one of the largest intermountain basins of the Khentei upland. Morphometric and trenching methods were applied to estimate the main parameters of seismogenic dislocations and associated Holocene palaeoearthquakes (540–2810, 3170–3720, and 7480–9220 years ago). The maximum palaeoearthquake magnitude (7.5) characterizes the seismic capacity of the potential focal area (PFA) confined to the Kerulen fault. The new data show the need to revise the potential seismicity concepts of the southern Khentey area and to make appropriate changes in the general seismic zoning maps. The relationship between the dislocations and the modern topography features, as well as deformation of the subsurface sediments in the studied mine openings give evidence of thrusting under the sub-lateral to north-western subhorizontal compression
GEODYNAMIC ACTIVITY OF MODERN STRUCTURES AND TECTONIC STRESS FIELDS IN NORTHEAST ASIA
Based on the analysis of changes in the stress-strain state of the crust at the boundary of the Eurasian and North American tectonic plates, we develop a dynamic model of the main seismogenerating structures inNortheast Asia. We have established a regularity in changes of geodynamic regimes within the interplate boundary between the Kolyma-Chukotka crustal plate and the Eurasian, North American and Pacific tectonic plates: spreading in the Gakkel Ridge area; rifting in the Laptev Sea shelf; a mixture of tectonic stress types in the Kharaulakh segment; transpression in the Chersky seismotectonic zone, in the segment from the Komandor to the Aleutian Islands, and in the Koryak segment; and crustal stretching in the Chukotka segment
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