91 research outputs found

    Broadening the frequencies of clinical sound: another lesson from COVID-19

    Full text link

    Reflections on Australian critical care echocardiography

    Full text link

    Point-of-care ultrasonography—An essential skill for medical graduates?

    Full text link
    The recent proliferation of point-of-care ultrasonography (POCUS) in the clinical practice of many medical specialties has exposed persistent barriers to education, training and standardisation. Specialist training curriculums are already overwhelming, having grossly insufficient time available for the specialist trainees and for the small number of available trainers alike to incorporate POCUS into postgraduate education. The logical solution to overcome these barriers could be to incorporate basic POCUS education and training into the undergraduate university curriculums, introducing longitudinal integration with other relevant medical sciences. The Australasian Society of Ultrasound in Medicine already has well-established educational programmes in POCUS with standardised assessment of competency, which could potentially offer the basis for symbiosis with the Australian and New Zealand medical schools

    Hydrogeoecological estimation of the fresh waters state of the Nadym-Pursk and Pur-Taz oil and gas provinces of the Yamal-Nenets Autonomous District in connection with intensive mining of hydrocarbon deposits

    Get PDF
    In recent years the problem of rational use and protection of the country’s groundwater resources has become increasingly important. This is due to want of reserves of groundwater and surface water, their depletion with technological progress and the ever increasing influence of human economic activity. The growth of cities, industry, expansion of water consumption for various economic needs significantly change the water balance regimes on the surface, in soils and rocks.The northern part of the West Siberian Artesian Megabasin (WSAMB) is located on the territory of the Yamal-Nenets Autonomous District (YNAD). Now the district is an intensively developing region of the Russian Federation. Here, oil and gas are extracted, large transport communications and residential areas are located. The district is characterized by extreme landscape, climatic and geoecological conditions that determine the nature of development of dangerous natural processes, the interaction of surface and groundwater and the migration of pollutants. The anthropogenic impact on the fresh groundwater of WSAMB and the increase in the residential load in the developed territories, which is intensified as a result of oil and gas production, requires an in-depth study of the regional hydrodynamics of the Upper Eocene Quaternary hydro-geological complex.The article provides calculations of mass flows of the main pollutants in groundwater and provides a preliminary forecast of the possible change in the quality of fresh water under the influence of anthropogenic factor

    Splitting the anterior mitral leaflet impairs left ventricular function in an ovine model

    Full text link
    OBJECTIVES: During mitral valve replacement, the anterior mitral leaflet is usually resected or modified. Anterior leaflet splitting seems the least disruptive modification. Reattachment of the modified leaflet to the annulus reduces the annulopapillary distance. The goal of this study was to quantify the acute effects on left ventricular function of splitting the anterior mitral leaflet and shortening the annulopapillary distance. METHODS: In 6 adult sheep, a wire was placed around the anterior leaflet and exteriorized through the left ventricular wall to enable splitting the leaflet in the beating heart. Releasable snares to reduce annulopapillary distance were likewise positioned and exteriorized. A mechanical mitral prosthesis was inserted to prevent mitral incompetence during external manipulations of the native valve. Instantaneous changes in left ventricular function were recorded before and after shortening the annulopapillary distance, then before and after splitting the anterior leaflet. RESULTS: After splitting the anterior leaflet, preload recruitable stroke work, stroke work, stroke volume, cardiac output, left ventricular end systolic pressure and mean pressure were significantly decreased by 26%, 23%, 12%, 9%, 15% and 11%, respectively. Shortening the annulopapillary distance was associated with significant decreases in the end systolic pressure volume relationship, preload recruitable stroke work, stroke work and left ventricular end systolic pressure by 67%, 33%, 15% and 13%, respectively. Shortening the annulopapillary distance after splitting the leaflet had no significant effect. CONCLUSIONS: Splitting the anterior mitral leaflet acutely impaired left ventricular contractility and haemodynamics in an ovine model. Shortening the annulopapillary distance after leaflet splitting did not further impair left ventricular function

    On the Propagation of Slip Fronts at Frictional Interfaces

    Get PDF
    The dynamic initiation of sliding at planar interfaces between deformable and rigid solids is studied with particular focus on the speed of the slip front. Recent experimental results showed a close relation between this speed and the local ratio of shear to normal stress measured before slip occurs (static stress ratio). Using a two-dimensional finite element model, we demonstrate, however, that fronts propagating in different directions do not have the same dynamics under similar stress conditions. A lack of correlation is also observed between accelerating and decelerating slip fronts. These effects cannot be entirely associated with static local stresses but call for a dynamic description. Considering a dynamic stress ratio (measured in front of the slip tip) instead of a static one reduces the above-mentioned inconsistencies. However, the effects of the direction and acceleration are still present. To overcome this we propose an energetic criterion that uniquely associates, independently on the direction of propagation and its acceleration, the slip front velocity with the relative rise of the energy density at the slip tip.Comment: 15 pages, 6 figure

    THE PRESENT STATE OF THE PROBLEM OF RICKETTSIOSES IN RUSSIA AND NEW APPROACHES TO THE CLASSIFICATION OF DISEASES CAUSED BY SPOTTED FEVER GROUP RICKETTSIAE

    Get PDF
    The paper presents analysis of the development and the current status of the doctrine about rickettsia and rickettsiosis. Progress in the study of Rickettsia is associated with, improved methods for their detection and isolation - using live biotechnological systems (cultivation in the experimental lines of ticks-sensitive lines of eukaryotic cells) in combination with methods of genotyping and. classical ricketsial methods. The development and. use of new methodological approaches to the study of tick-borne rickettsiae and other alpha-proteobacteria led to an important revision of ideas about genetic diversity, heterogeneity of antigenic and. biological characteristics, ecology and. contribution to the infectious pathology of various representatives of the order Rickettsiales in Russia

    Электрически управляемая структура с периодическим изменением волнового сопротивления для отклонения основного луча высоконаправленного излучателя миллиметрового диапазона длин волн

    Get PDF
    A new design of electrically tunable multilayer structure (deflector) millimeter wavelength range based on the periodic structure of the ferroelectric/linear dielectric is proposed. Numerical simulation results show the parameters of the deflector increase efficiency of the deflection angle of the main beam of the radiation pattern due to the dispersive properties of the structure in comparison with existing analogues.Предложена новая конструкция электрически перестраиваемой многослойной структуры (дефлектора) миллиметрового диапазона длин волн на основе периодической структуры сегнетоэлектрик/линейный диэлектрик. Результаты численного моделирования параметров дефлектора демонстрируют повышение эффективности управления углом отклонения основного луча диаграммы направленности за счет дисперсионных свойств структуры по сравнению с существующими аналогами
    corecore