Computer-assisted ex vivo, normothermic small bowel perfusion

Background: In the present study, a technique for computer-assisted, normothermic, oxygenated, ex vivo, recirculating small bowel perfusion was established as a tool to investigate organ pretreatment protocols and ischemia/reperfusion phenomena. A prerequisite for the desired setup was an organ chamber for ex vivo perfusion and the use of syngeneic whole blood as perfusate. Methods: The entire small bowel was harvested from Lewis rats and perfused in an organ chamber ex vivo for at least 2 h. The temperature was kept at 37 degrees C in a water bath. Three experimental groups were explored, characterized by different perfusion solutions. The basic perfusate consisted of syngeneic whole blood diluted with either NaCl, Krebs' solution or Krebs' solution and norepinephrine to a hematocrit of 30%. In addition, in each group l-glutamine was administered intraluminally. The desired perfusion pressure was 100 mm Hg which was kept constant with a computer-assisted data acquisition software, which measured an-line pressure, oxygenation, flow, temperature and pH and adjusted the pressure by changing the flow via a peristaltic pump. The viability of the preparation was tested by measuring oxygen consumption and maltose absorption, which requires intact enzymes of the mucosal brush border to break down maltose into glucose. Results: Organ perfusion in group 1 (dilution with NaCl) revealed problems such as hypersecretion into the bowel lumen, low vascular resistance and no maltose uptake. In contrast a viable organ could be demonstrated using Krebs' solution as dilution solution. The addition of norepinephrine led to an improved perfusion over the entire perfusion period. Maltose absorption was comparable to tests conducted with native small bower. Oxygen consumption was stable during the 2-hour perfusion period. Conclusions: The ex vivo perfusion system established enables small bowel perfusion for at least 2 h. The viability of the graft could be demonstrated. The perfusion time achieved is sufficient to study leukocyte/lymphocyte interaction with the endothelium of the graft vessels. In addition, a viable small bowel, after 2 h of ex vivo perfusion, facilitates testing of pretreatment protocols for the reduction of the immunogenicity of small bowel allografts. Copyright (C) 2000 S. Karger AG, Basel

Разработка интерактивного образовательного ресурса кафедры "Электроника и автоматика физических установок"

Объектом разработки выпускной квалификационной работы является разработка интерактивного образовательного ресурса кафедры «Электроника и автоматика физических установок». Цель работы – разработка интерактивного образовательного ресурса кафедры «Электроника и автоматика физических установок». В процессе разработки проводилось рассмотрение вопросов анализа и выбора современных программно-технических средств для непосредственной реализации интерактивного образовательного ресурса кафедры «Электроника и автоматика физических установок». В результате выполнения работы разработан интерактивный образовательный ресурс кафедры «Электроника и автоматика физических установок»The object of the development of the final qualifying work is to develop an interactive educational resource of the department "Electronics and automation of physical installations." Purpose of work - to develop interactive educational resource of the department "Electronics and automation of physical installations." During the development process was carried out consideration of analysis and selection of modern software and hardware tools for direct implementation of an interactive educational resource of the department "Electronics and automation of physical installations." As a result of the work developed an interactive educational resource of the department "Electronics and automation of physical facilities

Ferromagnetism of 3^3He Films in the Low Field Limit

We provide evidence for a finite temperature ferromagnetic transition in 2-dimensions as $H \to 0$ in thin films of $^3$He on graphite, a model system for the study of two-dimensional magnetism. We perform pulsed and CW NMR experiments at fields of 0.03 - 0.48 mT on $^3$He at areal densities of 20.5 - 24.2 atoms/nm$^2$. At these densities, the second layer of $^3$He has a strongly ferromagnetic tendency. With decreasing temperature, we find a rapid onset of magnetization that becomes independent of the applied field at temperatures in the vicinity of 1 mK. Both the dipolar field and the NMR linewidth grow rapidly as well, which is consistent with a large (order unity) polarization of the $^3$He spins.Comment: 4 figure