36 research outputs found

    Acute Modifications of Circulating Volume and Respiratory Maneuvers in the Cardiovascular Assessment of Long-Duration Crewmembers

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    This U.S. - Russian project is aimed at improved assessment of cardiac and vascular parameters associated with circulating volume and its distribution in long-duration space flight. Objective responses to modified Valsalva and Mueller maneuvers were measured by cardiac and vascular ultrasound before, during, and after temporary volume redistribution by means of Braslet-M thigh occlusion cuffs (Russia). Braslet-M cuffs are custom fitted to each crewmember prior to launch on the Soyuz as a Russian countermeasure for space adaptation fluid shift

    Right Ventricular Tissue Doppler Assessment in Space During Circulating Volume Modification using the Braslet-M Device

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    This joint U.S. - Russian work aims to establish a methodology for assessing cardiac function in microgravity in association with manipulation of central circulating volume. Russian Braslet-M occlusion cuffs were used to temporarily increase the volume of blood in the lower extremities, which effectively reduces the volume returning to the heart in the central circulation. A novel methodology was tested on the International Space Station (ISS) to assess the volume status of crewmembers by evaluating the responses to application and release of the Braslet-on-occlusion cuffs, as well as to modified Valsalva and Mueller maneuvers. Baseline echocardiographic tissue Doppler imaging (TDI) of the right ventricular free wall with no Braslet applied shows early diastolic E' (16 cm/sec), late diastolic A' (14 cm/sec), and systolic (12 cm/sec) velocities compatible with normal subjects on Earth. TDI of the RV free wall with Braslet applied shows that early diastolic E' decreased by 50% (8 cm/sec), late diastolic A' increased by 45%, and systolic S' remains unchanged. TDI of the RV free wall approximately 8 beats after the Braslet was released shows early diastolic E' (8 cm/sec), late diastolic A' (12 cm/sec), and systolic S' (13 cm/sec) velocities. During this portion of the release, early diastolic E' did not recover to baseline values but late diastolic A' and systolic S' recovered to pre-Braslet values. The pre-systolic cross-sectional area of the internal jugular vein with Braslet off was 1.07 cm(sup 2) and 1.13 cm(sup 2) 10 min after the Braslet was applied. The presystolic cross-sectional area of the common femoral vein with Braslet off was 0.50 cm(sup 2), and was 0.54 cm(sup 2) 10 min after the Braslet was applied. The right ventricular myocardial performance Tei index also was calculated for comparison with typical values found in healthy subjects on Earth. Baseline and Braslet-on values for Tei index were 0.25 and 0.22 respectively. Braslet Tei indices are within normal ranges found in healthy subjects and temporarily become greater than 0.4 during the dynamic Braslet release portion of this study. Tissue Doppler imaging of the right ventricle revealed that the Braslet influenced cardiac preload and that fluid was sequestered in the lower-extremity interstitial and vascular space after only 10 minutes of application. This report demonstrates that Braslet application affects right ventricular physiology in long-duration space flight based on TDI and that this effect is in part due to venous hemodynamics

    ОПЫТ ИСПОЛЬЗОВАНИЯ РЕНТГЕНОВСКОГО КОМПЬЮТЕРНОГО ТОМОГРАФА В ИССЛЕДОВАНИИ СТРУКТУРЫ ДЕРЕВЯННЫХ ОСНОВ ДРЕВНЕРУССКИХ ИКОН ИЗ СОБРАНИЯ ЧЕЛЯБИНСКОГО ГОСУДАРСТВЕННОГО МУЗЕЯ ИЗОБРАЗИТЕЛЬНЫХ ИСКУССТВ

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    The research is concerned with description of CT application aiming to approximate refinement of icon painting period using x-ray analysis of its material structure. Data received may provide the basis for works of art stratification.В данной работе описываются возможности применения компьютерной томографии с целью ориентировочного уточнения периода написания иконы путем рентгенологического анализа структуры ее материалов. Полученные данные могут быть положены в основу стратификации произведений искусства

    FUNCTIONS AND STRUCTURE OF THE UNIVERSITY COMPLEX MECHANISM WHICH SERVES EDUCATIONAL INTERESTS

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    The article deals with the functions and structure of the university as a corporate complex mechanism which serves educational interests. Its exploration is needed for a more harmonious and balanced passing reformation process and modernization of education in Ukraine in accordance with European trends. Technical model of university was formed and comparison of the university and company structure was made. Some conclusions about existing problems of education process efficiency and the ways of its solutions were made. There are critical modern views on the education system as a competitive member of the economy market in this article

    Introduction of Carbonyl Groups into Antibodies

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    Antibodies and their derivatives (scFv, Fabs, etc.) represent a unique class of biomolecules that combine selectivity with the ability to target drug delivery. Currently, one of the most promising endeavors in this field is the development of molecular diagnostic tools and antibody-based therapeutic agents, including antibody–drug conjugates (ADCs). To meet this challenge, it is imperative to advance methods for modifying antibodies. A particularly promising strategy involves the introduction of carbonyl groups into the antibody that are amenable to further modification by biorthogonal reactions, namely aliphatic, aromatic, and α-oxo aldehydes, as well as aliphatic and aryl–alkyl ketones. In this review, we summarize the preparation methods and applications of site-specific antibody conjugates that are synthesized using this approach
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