169 research outputs found

    Height gradient approach for occlusion detection in UAV imagery

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    The use of Unmanned Aerial Vehicle (UAV) significantly increased in the last years. It is used for several different applications, such as mapping, publicity, security, natural disasters assistance, environmental monitoring, 3D building model generation, cadastral survey, etc. The imagery obtained by this kind of system has a great potential. To use these images in true orthophoto generation projects related to urban scenes or areas where buildings are present, it is important to consider the occlusion caused by surface height variation, platform attitude, and perspective projection. Occlusions in UAV imagery are usually larger than in conventional airborne dataset due to the low-altitude and excessive change in orientation due to the low-weight and wind effects during the flight mission. Therefore, this paper presents a method for occlusion detection together with some obtained results for images acquired by a UAV platform. The proposed method shows potential in occlusion detection and true orthophoto generation401W4263268International Conference on Unmanned Aerial Vehicles in Geomatic

    Convolutional Neural Networks for Road Detection: An Unsupervised Domain Adaptation Approach

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    Due to the frequent road network changes, keeping them updated is fundamental for several purposes. Currently, models based on Deep Learning (DL), specifically, Convolutional Neural Networks (CNNs), such as encoder-decoder type, are state-of-the-art for this purpose. In this context, the high performance in CNNs has two aspects involved: the model needs a large labeled dataset, and the dataset belongs to the same probability distribution. In practical applications, however, this may not hold, since there is a domain shift effect, and it is not customary for the availability of labeled data. To approach these challenges, we propose to adapt the U-Net architecture (encoder-decoder) to the Unsupervised Domain Adaptation (UDA) that does not need labeling data to minimize the domain shift effect. Our results demonstrate that the proposed method contributes to road segmentation, whose model reaches 74.31% (IoU) and 85.04% (F1), against the same model without UDA that reaches 67.36% (IoU) and 80.02% (F1). This implies that the information that comes from the target domain, even unsupervised, contributes to adversarial learning, improving the generalization capacity of the model, enhancing aspects such as better discrimination surrounding classes, and in the geometric delineation of the road network

    Высокая проницаемость мембран для гемодиализа: плюсы и минусы

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    Up-to-date technologies have led to significant improvement of haemodialysis membranes biocompatibility and permeability. The new classes of membranes, high cut-off and middle cut-off, allow enhanced removal of middle molecules such as β2-microglobulin and even larger molecules. High membrane permeability along with the wide use of convective modalities are accompanied by increased albumin loss during dialysis. What is the acceptable upper limit for this loss and where is the right balance between the benefit of enhanced uremic substances removal and potential adverse effects of albumin deprivation are the active areas of research.Современные технологии производства мембран для гемодиализа позволили существенно повысить их биосовместимость и проницаемость. Новые разновидности мембран – с высокой и средней точками отсечения по молекулярной массе просеивающихся веществ – позволяют эффективно удалять не только средние молекулы, такие как β2 -микроглобулин, но и более размерные молекулы. Высокая проницаемость современных диализных мембран и широкое внедрение конвективных методик сопряжены с повышенной потерей альбумина в ходе сеансов лечения. Какой уровень таких потерь можно считать приемлемым и где находится точка равновесия между преимуществами повышенного выведения уремических соединений и потенциальной опасностью избыточного просеивания альбумина – эти вопросы требуют дальнейших исследований

    Оптимизация конвекционного потока при онлайн гемодиафильтрации

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    Objective: to evaluate the dependence of the magnitude of convection flow in online hemodiafiltration (OLHDF) on ultrafiltration control method and patients’ individual characteristics. Materials and methods. The study included 36 stable dialysis patients (20 male and 16 female). The substitution rate was conducted manually based on transmembrane pressure (TMP). In some cases, devices with automatic filtration rate control unit AutoSub plus were used. The filtration rate (FR), TMP, blood flow rate (Qb), specific filtration rate (SFR, m/l/min/mm Hg–1 ) were recorded. Results. The maximum SFR in various patients ranged from 0.51 to 0.80 ml/min/mm Hg–1 ; average value was 0.62 ± 0.07 ml/min/mm Hg–1 . There was significant correlation of SFR with hemoglobin level (r = –0.55). SFR reduced during hemodiafiltration (on average – by 23 ± 4%). SFR was significantly affected by Qb (r = 0.70). Maximum SFR was achieved with a TMP of 140–220 mm Hg; with TMP over 250 mm Hg, a decrease in SFR was noted, an increase in Qb was required for further increase in FR. Individual stability of SFR was noted during serial observations; fluctuations in a particular patient did not exceed 10%. Substitution volume for the HDF session was 18.0 ± 3.3 L, the FR/Qb ratio was 24.7 ± 5.2%. Substitution volume of 21 L was not achieved in 17 of 36 patients. The use of automatic FR adjustment system made it possible to increase the substitution volume (SV) by 12–18%. Conclusion. Achieving maximum convection volume in OLHDF requires individualizing treatment parameters. The use of FR automatic control allows maximum possible convection flow.Цель: изучить зависимость величины конвекционного потока при онлайн гемодиафильтрации (олГДФ) от способа управления ультрафильтрацией и индивидуальных особенностей пациентов. Материалы и методы. В исследование были включены 36 пациентов (20 мужчин и 16 женщин), находящихся на лечении программным гемодиализом. Управление скоростью замещения проводилось в ручном режиме на основании показателей трансмембранного давления (ТМД). В ряде случаев использовались аппараты с блоком автоматического управления скоростью фильтрации (СФ) AutoSub plus. Фиксировались СФ, ТМД, скорость кровотока (СК), удельная скорость фильтрации (УСФ, мл/мин/мм рт. ст.–1 ). Результаты. Максимальная УСФ у различных пациентов колебалась в пределах 0,51–0,80 мл/мин/мм рт. ст.–1 , среднее значение составило 0,62 ± 0,07 мл/мин/мм рт. ст.–1 . Была отмечена значимая корреляция УСФ с уровнем гемоглобина (r = –0,55). В течение процедуры отмечалось снижение УСФ (в среднем – на 23 ± 4%). На величину УСФ оказывала существенное влияние СК (r = 0,70). Максимальная УСФ достигалась при ТМД 140–220 мм рт. ст., при ТМД свыше 250 мм рт. ст. отмечалось падение УСФ, и для дальнейшего прироста СФ требовалось увеличение скорости кровотока. При серийных наблюдениях была отмечена индивидуальная стабильность УСФ, колебания у конкретного пациента не превышали 10%. Объем замещения за сеанс ГДФ составил 18,0 ± 3,3 л, соотношение СФ/СК 24,7 ± 5,2%, при этом у 17 из 36 пациентов не был достигнут объем замещения 21 л. Применение автоматической системы регулировки СФ позволяло увеличить объем замещения (ОЗ) на 12–18%. Заключение. Достижение максимального конвекционного объема при олГДФ требует индивидуализации параметров лечения. Применение автоматического управления СФ позволяет обеспечить максимально возможный конвекционный поток

    АНТИКОАГУЛЯЦИЯ ПРИ ЗАМЕСТИТЕЛЬНОЙ ПОЧЕЧНОЙ ТЕРАПИИ: КЛАССИЧЕСКИЕ ПОДХОДЫ И НОВЫЕ ВОЗМОЖНОСТИ

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    Clotting prevention is one of the key problems in renal replacement therapy. In this review traditional heparini- zation and its complications, low molecular weight heparins, which are wide used in programme haemodialysis, treatment without anticoagulants, regional citrate anticoagulantion, as well as new alternative anticoagulants are considered. Применение антикоагулянтов является одним из ключевых моментов при заместительной почечной те- рапии. В данном обзоре литературы рассмотрены традиционная гепаринизация и ее осложнения, низко- молекулярные гепарины, широко применяющиеся в программном гемодиализе, безгепариновый диализ, регионарная цитратная антикоагуляция, а также современные альтернативные антикоагулянты.

    Extracellular vesicle features are associated with COVID-19 severity

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    COVID-19 is heterogeneous; therefore, it is crucial to identify early biomarkers for adverse outcomes. Extracellular vesicles (EV) are involved in the pathophysiology of COVID-19 and have both negative and positive effects. The objective of this study was to identify the potential role of EV in the prognostic stratification of COVID-19 patients. A total of 146 patients with severe or critical COVID-19 were enrolled. Demographic and comorbidity characteristics were collected, together with routine haematology, blood chemistry and lymphocyte subpopulation data. Flow cytometric characterization of the dimensional and antigenic properties of COVID-19 patients' plasma EVs was conducted. Elastic net logistic regression with cross-validation was employed to identify the best model for classifying critically ill patients. Features of smaller EVs (i.e. the fraction of EVs smaller than 200 nm expressing either cluster of differentiation [CD] 31, CD 140b or CD 42b), albuminemia and the percentage of monocytes expressing human leukocyte antigen DR (HLA-DR) were associated with a better outcome. Conversely, the proportion of larger EVs expressing N-cadherin, CD 34, CD 56, CD31 or CD 45, interleukin 6, red cell width distribution (RDW), N-terminal pro-brain natriuretic peptide (NT-proBNP), age, procalcitonin, Charlson Comorbidity Index and pro-adrenomedullin were associated with disease severity. Therefore, the simultaneous assessment of EV dimensions and their antigenic properties complements laboratory workup and helps in patient stratification

    ОНЛАЙН-ГЕМОДИАФИЛЬТРАЦИЯ: КЛИНИЧЕСКИЕ РЕЗУЛЬТАТЫ И ЭКОНОМИЧЕСКАЯ ЭФФЕКТИВНОСТЬ

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    Second part of review summarizes legal and financial aspects of online hemodiafiltration and its influence on short-term and long-term treatment results. According to recently completed randomized clinical trials, high vo- lume online hemodiafiltration is able to improve patients' survival rate. The results mentioned in the review must overpower the inertia which obstructs a wide implementation of online hemodiafiltration into routine clinical practice. Вторая часть обзора посвящена правовым и финансовым аспектам онлайн-гемодиафильтрации, а также ее влиянию на непосредственные и отдаленные результаты лечения. Недавно завершенные рандомизи- рованные исследования подтвердили, что высокообъемная онлайн-гемодиафильтрация позволяет улуч- шить выживаемость пациентов. Эти данные должны переломить инерцию, препятствующую повсемес- тному внедрению онлайн-гемодиафильтрации в качестве основной методики в практику программного гемодиализа.

    ACUTE KIDNEY INJURY: HISTORICAL ASPECTS AND DIAGNOSTIC CRITERIA

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    The in-depth review is dedicated to the acute kidney injury. This conception is wider than acute renal failure. Even minor decline of renal function bias outcomes, so early diagnosis of acute renal injury is exceedingly important. The new markers of kidney injury are actively investigated. RIFLE criteria provide universal approach to a problem at first, and allow comparison of study results at second
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