ВОЗВРАЩЕНИЕ К ЖИЗНИ ПОСЛЕ ХОЛОДОВОЙ ОСТАНОВКИ ДЫХАНИЯ ФИЗИОЛОГИЧЕСКИМИ МЕТОДАМИ БЕЗ ОТОГРЕВАНИЯ ТЕЛА

The arrest of respiration during deep hypothermia means death, though at a low temperature the heart may rhythmically contract for 30–40 minutes more. The attempts of rewarming only shorten the time before the heart arrest. “The aim of the study” the attempts to develop the methods of stimulating the respiration and heart without rewarming the body. Calcium ions (Ca2+) are believed to accumulate in the nervous cells in cold. An excess of these ions inhibits the metabolism. Moreover it stimulates the cell proteases, which destroy the cell membranes. “Materials and methods” The work was carried out on wite rats 250-320 g in weight. We introduced disodium salt of ethylenediaminetetraacetic acid (EDTA) into the animals. The second method of blocking the mechanisms of the cold death was artificial respiration. “Results”EDTA  reacts with calcium ions, decreases their quantity in the blood, and, consequently, in a complex manner in the cell protoplasm. Artificial respiration not only increases the flow of oxygen into an organism but also decreases the lowest temperature threshold of the cold death of an organism. “Conclusions” A decrease in the surviving threshold by 1.5-1.8oC is very important from the point of view of reanimation of an organism since to preserve life in the critical period of reanimation each 0.5oC are important. Prolongation of minimal frequency of heart contractions and maintaining a minimal arterial blood pressure in an overcooled organism given the body temperature of 11-12.5oC is a special problem of great interest associated with many physiological and biological parameters.  Остановка дыхания при глубокой гипотермии означает смерть, хотя сердце при низкой температуре может еще ритмически сокращатьсядо 30–40 мин. Попытки отогревания лишь приближают время остановки сердца. Принято считать, что в холоде в нервных клетках накапливаются ионы кальция (Ca2+). Избыток этих ионов тормозит метаболизм. Кроме того, он стимулирует протеазы клетки, которые разрушают клеточные мембраны. Цель исследования: осуществить попытку разработки методов стимуляции дыхания и сердца без отогревания тела. Материалы и методы: работа проводилась на белых крысах весом 250–320 г. Животным вводили динатриевую соль этилендиаминтетрауксусной кислоты. Вторым методом блокады механизмов холодовой смерти было искусственное дыхание. Результаты: этилендиаминтетрауксусная кислота вступает в реакцию с ионами кальция, уменьшает их количество в крови и, соответственно, сложным образом, в протоплазме клеток. Искусственное дыхание не только увеличивало приток кислорода в организм, но и понижало нижний температурный порог холодовой смерти организма. Выводы: снижение температурного порога выживания охлажденного организма на 1,5–1,8 °С очень важно с точки зрения процесса реанимации организма, поскольку для сохранения жизни в критическом периоде реанимации важны каждые 0,5 °С. Продление минимальной частоты сокращений сердца и поддержание минимального артериального кровяного давления у переохлажденного организма при температуре тела 11–12,5 °С является особой проблемой, которая связана с многими физиологическими и биологическими параметрами и представляет большой интерес

КРИТИЧЕСКИЙ ОБЗОР МЕХАНИЗМОВ ПРЕКОНДИЦИОНИРОВАНИЯ

Adaptation of the brain and myocardium to ischemia by short shutdowns of the regional circulation (preconditioning) is an interesting and important subject. Nowadays it is discussed with animation in the scientific literature. However this problem is very complicated and contains a lot of contradictions. We tried to examine these contradictions and to find the reasons for this phenomenon. Адаптация мозга и миокарда к ишемии путем кратких выключений регионального кровообращения (прекондиционирования) — интересная и важная тема, которая в настоящее время активно обсуждается в научной литературе. Однако эта проблема очень сложна и содержит в себе много противоречий. В данной статье мы попытались проанализировать противоречия и установить причины этого феномена.

СОВРЕМЕННЫЕ МЕДИЦИНСКИЕ ПРОБЛЕМЫ ЭНЕРГООБМЕНА У ЧЕЛОВЕКА

In a living organism 72% of energy exchange occur in the visceral organs, which comprise only 5-6% of the total body mass. The remaining energy is spent at the expense of the skin, bones, connective tissues, resting muscles. The level of energy expenditure determines the general physiological state of a human organism, serves for the diagnostics of various diseases, in particular, the diseases of endocrine system, the disruptions of thermoregulation, protein, carbohydrate, and lipometabolism, etc. It should be mentioned that in modern textbooks of physiology, pathophysiology, and biology the problem of energy exchange in humans and animals is given inadequate consideration. Traditionally it occupies only 2-2.5% of the content. Meanwhile, new problems of energy exchange have appeared recently, which almost never were advanced earlier. These are, for example, the reasons and mechanisms of high energy expenditure under conditions of metabolism, the significance of the coefficient of efficiency of a human organism in physiology, special processes previously unknown of the organism heat exchange with the environment, physiological and social components of human energy exchange. There is also a problem of a theoretical possibility of life without energy . В живом организме 72% энергообмена происходит во внутренних органах, которые составляют всего 5–6% от общей массы тела. Остальная энергия затрачивается за счет кожи, костей, соединительной ткани, покоящихся мышц. Уровень потребления энергии определяет общее физиологическое состояние организма человека, служит для диагностики различных заболеваний, в особенности ― болезней эндокринной системы, нарушений терморегуляции, нарушений белкового, углеводного и жирового обмена и др. Следует сказать, что в современных учебниках по физиологии, патофизиологии и биологии вопрос об энергообмене человека и животных рассматривается недостаточно подробно. Обычно он занимает только 2–2,5% содержания. Между тем в последние время появились новые проблемы энергообмена, которые раньше почти никогда не выдвигались. Это, например, причины и механизмы высокого потребления энергии в условиях основного обмена, значение в физиологии коэффициента полезного действия организма человека, неизвестные ранее особые процессы теплообмена организма со средой, физиологические и социальные составляющие энергообмена человека. Существует также вопрос о теоретической возможности жизни без энергии

The Geometry of D=11 Killing Spinors

We propose a way to classify all supersymmetric configurations of D=11 supergravity using the G-structures defined by the Killing spinors. We show that the most general bosonic geometries admitting a Killing spinor have at least a local SU(5) or an (Spin(7)\ltimes R^8)x R structure, depending on whether the Killing vector constructed from the Killing spinor is timelike or null, respectively. In the former case we determine what kind of local SU(5) structure is present and show that almost all of the form of the geometry is determined by the structure. We also deduce what further conditions must be imposed in order that the equations of motion are satisfied. We illustrate the formalism with some known solutions and also present some new solutions including a rotating generalisation of the resolved membrane solutions and generalisations of the recently constructed D=11 Godel solution.Comment: 36 pages. Typos corrected and discussion on G-structures improved. Final version to appear in JHE

The Geometry of D=11 Null Killing Spinors

We determine the necessary and sufficient conditions on the metric and the four-form for the most general bosonic supersymmetric configurations of D=11 supergravity which admit a null Killing spinor i.e. a Killing spinor which can be used to construct a null Killing vector. This class covers all supersymmetric time-dependent configurations and completes the classification of the most general supersymmetric configurations initiated in hep-th/0212008.Comment: 30 pages, typos corrected, reference added, new solution included in section 5.1; uses JHEP3.cl

Physics of Solar Prominences: I - Spectral Diagnostics and Non-LTE Modelling

This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (ie when there is a departure from Local Thermodynamic Equilibrium) radiative transfer models. We first describe the spectral inversion techniques that have been used to infer the plasma parameters important for the general properties of the prominence plasma in both its cool core and the hotter prominence-corona transition region. We also review studies devoted to the observation of bulk motions of the prominence plasma and to the determination of prominence mass. However, a simple inversion of spectroscopic data usually fails when the lines become optically thick at certain wavelengths. Therefore, complex non-LTE models become necessary. We thus present the basics of non-LTE radiative transfer theory and the associated multi-level radiative transfer problems. The main results of one- and two-dimensional models of the prominences and their fine-structures are presented. We then discuss the energy balance in various prominence models. Finally, we outline the outstanding observational and theoretical questions, and the directions for future progress in our understanding of solar prominences.Comment: 96 pages, 37 figures, Space Science Reviews. Some figures may have a better resolution in the published version. New version reflects minor changes brought after proof editin

Star Formation and Dynamics in the Galactic Centre

The centre of our Galaxy is one of the most studied and yet enigmatic places in the Universe. At a distance of about 8 kpc from our Sun, the Galactic centre (GC) is the ideal environment to study the extreme processes that take place in the vicinity of a supermassive black hole (SMBH). Despite the hostile environment, several tens of early-type stars populate the central parsec of our Galaxy. A fraction of them lie in a thin ring with mild eccentricity and inner radius ~0.04 pc, while the S-stars, i.e. the ~30 stars closest to the SMBH (<0.04 pc), have randomly oriented and highly eccentric orbits. The formation of such early-type stars has been a puzzle for a long time: molecular clouds should be tidally disrupted by the SMBH before they can fragment into stars. We review the main scenarios proposed to explain the formation and the dynamical evolution of the early-type stars in the GC. In particular, we discuss the most popular in situ scenarios (accretion disc fragmentation and molecular cloud disruption) and migration scenarios (star cluster inspiral and Hills mechanism). We focus on the most pressing challenges that must be faced to shed light on the process of star formation in the vicinity of a SMBH.Comment: 68 pages, 35 figures; invited review chapter, to be published in expanded form in Haardt, F., Gorini, V., Moschella, U. and Treves, A., 'Astrophysical Black Holes'. Lecture Notes in Physics. Springer 201

Neutrino Cooling of Neutron Stars. Medium effects

This review demonstrates that neutrino emission from dense hadronic component in neutron stars is subject of strong modifications due to collective effects in the nuclear matter. With the most important in-medium processes incorporated in the cooling code an overall agreement with available soft X ray data can be easily achieved. With these findings so called "standard" and "non-standard" cooling scenarios are replaced by one general "nuclear medium cooling scenario" which relates slow and rapid neutron star coolings to the star masses (interior densities). In-medium effects take important part also at early hot stage of neutron star evolution decreasing the neutrino opacity for less massive and increasing for more massive neutron stars. A formalism for calculation of neutrino radiation from nuclear matter is presented that treats on equal footing one-nucleon and multiple-nucleon processes as well as reactions with resonance bosons and condensates. Cooling history of neutron stars with quark cores is also discussed.Comment: To be published in "Physics of Neutron Star Interiors", Eds. D. Blaschke, N.K. Glendenning, A. Sedrakian, Springer, Heidelberg (2001

Towards a new image processing system at Wendelstein 7-X: From spatial calibration to characterization of thermal events

Wendelstein 7-X (W7-X) is the most advanced fusion experiment in the stellarator line and is aimed at proving that the stellarator concept is suitable for a fusion reactor. One of the most important issues for fusion reactors is the monitoring of plasma facing components when exposed to very high heat loads, through the use of visible and infrared (IR) cameras. In this paper, a new image processing system for the analysis of the strike lines on the inboard limiters from the first W7-X experimental campaign is presented. This system builds a model of the IR cameras through the use of spatial calibration techniques, helping to characterize the strike lines by using the information given by real spatial coordinates of each pixel. The characterization of the strike lines is made in terms of position, size, and shape, after projecting the camera image in a 2D grid which tries to preserve the curvilinear surface distances between points. The description of the strike-line shape is made by means of the Fourier Descriptors