New insights into microstructure of irradiated beryllium based on experiments and computer simulations

The microstructural response of beryllium after neutron irradiation at various temperatures (643–923 K) was systematically studied using analytical transmission electron microscope that together with outcomes from advanced atomistic modelling provides new insights in the mechanisms of microstructural changes in this material. The most prominent feature of microstructural modification is the formation of gas bubbles, which is revealed at all studied irradiation temperatures. Except for the lowest irradiation temperature, gas bubbles have the shape of thin hexagonal prisms with average height and diameter increasing with temperature. A high number density of small bubbles is observed within grains, while significantly larger bubbles are formed along high-angle grain boundaries (GB). Denuded zones (DZ) nearly free from bubbles are found along both high- and low-angle grain boundaries. Precipitations of secondary phases (mainly intermetallic Al-Fe-Be) were observed inside grains, along dislocation lines and at GBs. EDX analysis has revealed homogeneous segregation of chromium and iron along GBs. The observed features are discussed with respect to the available atomistic modelling results. In particular, we present a plausible reasoning for the abundant formation of gas bubbles on intermetallic precipitates, observation of various thickness of zones denuded in gas bubbles and precipitates, and their relation to the atomic scale diffusion mechanisms of solute-vacancy clusters

Mitochondrial dysfunction at atherosclerosis and myocardial infarction: molecular and cytochemical cell-markers

We studied capabilities of confocal laser scanning microscopy in the analysis of lipid droplets volume and of quantity of functional mitochondria and reactive oxygen species production in liver cells for early diagnosis of cytochemical disturbances at dyslipoproteinemia (16 days of experiment). The results showed the increase of lipid droplets volume in hepatocytes, decrease of functional mitochondria and increase of reactive oxygen species production. We evaluated the potential of real-time PCR method in the analysis of mitochondrial DNA of blood plasma at early stages of dyslipoproteinemia and in experimental infarction. On the background of registered blood lipid metabolism disorders and structural and functional changes in liver cells, we determined the tendency to three-time increase in concentration of circulating cell-free mtDNA on the 16th day of dyslipoproteinemia as compared to the control data. We used a model of myocardial infarction to show statistically significant increase in the level of circulating cell-free blood mtDNA from 48 hours after adrenaline injection and we found that this level maintained up to 144 hours after adrenaline injection. Obtained data can serve as a basis for creation of technologies for diagnostic monitoring of atherosclerosis and myocardial infarction severity

Acute myocardial ischemia: changes of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery

The aim of the present study is to analyze the dynamics of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery. We showed that the concentration of free circulating mtDNA of blood tends to decrease 24 hours after ligation; it increased and reached values close to control samples 48 and 72 hours after ligation. These data define the need in further investigation of the dynamics of this parameter during later periods of myocardial infarction modeling that will contribute to objective evaluation of its significance for acute myocardial damage diagnostics and prognosis

Роль жирных кислот плазмы крови в патогенезе стабильной стенокардии

In men and women suffering from stable angina pectoris of 1-2 functional classes and aged from 35 to 69 years old, decrease of C 23:0 and increase of C 18:1(11) fatty acids was observed regardless of sex, the content of the rest fatty acids changed depending on patients sex. Correlation was found that metabolism of fatty acids in this pathology group depends on patients sex: men in the control group showed decrease in the sum of omega-3 fatty acids as well as in the omega-3/omega-6 fatty acid ratio, while women showed decrease of omega-6 fatty acids at the constant sum of omega-3 fatty acids. Regardless of sex, the presence of this pathology is accompanied with decrease in correlations between fatty acids, as the number of correlations between saturated fatty acids increases and the number of correlations between not saturated and saturated fatty aсids decreases. Change in correlations between not saturated fatty acids depends on sex. In the number of patients having supernormal fatty acid contents, no pronounced differences were found between men and women.У мужчин и женщин, больных стабильной стенокардией 1-2-го функционального класса, в возрасте от 35 до 69 лет вне зависимости от пола отмечено уменьшение содержания С23:0 и увеличение содержания С18:1(11), остальные жирные кислоты (ЖК) изменялись разнонаправленно. Выявлена зависимость метаболизма ЖК при данной патологии от пола: если у мужчин опытной группы отмечается уменьшение суммы ЖК ω-3 и отношения ω-3/ω-6 при неизменной сумме ω-6, то у женщин уменьшается общее содержание ω-6 при неизменной сумме ω-3. Наличие патологии вне зависимости от пола сопровождается уменьшением общего числа корреляций между ЖК при нарастании удельного веса корреляций между насыщенными ЖК и уменьшении числа корреляций между ненасыщенными и насыщенными ЖК. Изменение корреляций между ненасыщенными ЖК зависит от пола. По количеству больных, имеющих показатели ЖК, выходящие за пределы нормы, выраженных различий между мужчинами и женщинами не обнаружено