Features of radiation damage of Ni-Ti alloy under exposure to heavy ions of gaseous elements

The consistent patterns of changes in structural and phase state, hardening and temperature ranges of martensitic transformations in Ni-Ti alloy with the shape memory effect after implantation of heavy ions 16O3+, 40Ar8+ and 84Kr15+ under comparable parameters have been experimentally studied. It is found that under the impact of 84Kr15+ ions, a two-layer surface structure with radiation-hardened second layer is formed, radiation-stimulated phase transformation B19'>B2 occurs in the near-surface layer and out-range area, and the martensitic transformation temperature increases toward higher values after implantation of 40Ar8+ and 84Kr15+ ions

Radiation Hardening of Ni-Ti Alloy Under Implantation of Inert Gases Heavy Ions

The consistent patterns of changes in nano- and micro-hardness of Ni-Ti alloy with the shape memory effect after implantation of [40]Ar{8+} and [84]Kr{15+} ions depending on phase composition and implantation parameters have been experimentally studied. It has been shown that softening by 4 and 14% near the surface of the two-phase Ni-Ti alloy after implantation of [40]Ar{8+} and [84]Kr{15+} ions is connected with the differences in the nanostructure. Hardening of the near-surface layer of this alloy maximum by 118% at h=~3 pm and single-phase alloy in the entire region of the [40]Ar{8+} and [84]Kr{15+} ions range and in the out-range (h>R[p]) area have been detected. The role of the current intensity of the ions beam in the change of nanohardness for the two-phase Ni-Ti alloy has been established

Subpopulation composition of peripheral blood lymphocytes in COVID-19

The pathogenesis of severe coronavirus infection COVID-19 is associated with activation of immune system, cytokine storm, impaired blood clotting, microvascular thrombosis, organ ischemia and multiple organ dysfunction syndrome. The role of various lymphocyte subpopulations in COVID-19 is still debated. The aim of our study was to analyze the subpopulational profile of peripheral blood lymphocytes in COVID-19 patients as compared with healthy donors.The study included 20 COVID-19 patients (11 males and 9 females,) and 26 healthy donors. Average age of the patients was 52 and 56 years, respectively. Clinical examinations were performed by standard laboratory methods. Peripheral blood lymphocytes were isolated in the Ficoll gradient. The cells were stained with antibodies to specific antigens of main lymphocyte populations, endothelial cells, and apoptotic cell markers. The analysis was performed by flow cytometry. The results showed that all patients had elevated C-reactive protein (14- to 35-fold), ferritin (1.2- to 13-fold), D-dimers (1.2- to 90-fold). 55% of men had a decrease in the absolute number of lymphocytes, in women this index was at the low normal limit. Cytometric analysis showed that, among peripheral blood lymphocytes, the proportion of functional cells expressing the CD45 marker ranged from 2 to 12% in 70% of patients, as compared with 80-99% among the donors. The proportion of CD45+ lymphocytes significantly correlated with the level of hemoglobin, but not with the levels of inflammatory biochemical markers. Among the functional lymphocytes of patients, there was a decrease in the proportion of CD3+, CD4+, CD8+T cells, increased proportion of natural killer CD56+ and the apoptotic (AnnexinV+) cell contents, but the proportion of CD19 and HLA-DR+B cells was not changed. Analysis of the lymphocyte (LC) subpopulations that did not express CD45 marker showed that this fraction contained different lymphocyte subsets with reduced expression of CD4, CD8, CD19, CD56 etc. in the blood of patients and donors. Higher percentage of endothelial cells expressing CD62P marker made the difference between patients and donors.Laboratory determination of lymphocyte subsets in blood samples of COVID-19 patients does not reflect the real severity pattern of the disease, thus requiring studies of the CD45-expressing functional cell populations

Radiation thermal processes in Cr13Mo2NbVB steel - the material of the fuel assembly shell in reactor BN-350 under mechanical tests

Regularities of changes of structural-phase state and mechanical properties of steel 13Mo2NbVB - the material of the fuel assembly shell in reactor BN-350 after various mechanical tests at 350°C are experimentally studied. The formation of microprecipitations FeMo, enriched or depleted with molybdenum was found in the short-time mechanical tests, which is the cause of thermal hardening of irradiated Cr13Mo2NbVB steel and its destruction by the ductile-brittle mechanism. On the basis of long-time creep tests it was shown that the material of the spent fuel assembly shell has sufficient resource for long-time storage in the temperature and force conditions simulating long-time storage of spent nuclear fuel

Radiation thermal processes in Cr13Mo2NbVB steel - the material of the fuel assembly shell in reactor BN-350 under mechanical tests

Regularities of changes of structural-phase state and mechanical properties of steel 13Mo2NbVB - the material of the fuel assembly shell in reactor BN-350 after various mechanical tests at 350°C are experimentally studied. The formation of microprecipitations FeMo, enriched or depleted with molybdenum was found in the short-time mechanical tests, which is the cause of thermal hardening of irradiated Cr13Mo2NbVB steel and its destruction by the ductile-brittle mechanism. On the basis of long-time creep tests it was shown that the material of the spent fuel assembly shell has sufficient resource for long-time storage in the temperature and force conditions simulating long-time storage of spent nuclear fuel

МОНИТОРИНГ ИЗМЕНЕНИЙ НАПРЯЖЕННО-ДЕФОРМИРОВАННОГО СОСТОЯНИЯ ГЕОСРЕДЫ В РАЙОНЕ ПЕТРОПАВЛОВСКОГО ГЕОДИНАМИЧЕСКОГО ПОЛИГОНА ПО ДАННЫМ КОМПЛЕКСНЫХ СКВАЖИННЫХ И GPS-ИЗМЕРЕНИЙ НА АКТИВНОЙ ФАЗЕ ПОДГОТОВКИ ЖУПАНОВСКОГО ЗЕМЛЕТРЯСЕНИЯ (30.01.2016; Mw=7.2)

The paper presents the results of comparative analysis of the data regarding the multi-instrumental borehole monitoring data of changes in the geoenvironment stress-strain state and GPS data obtained in the time vicinity of the close strong Zhupanovsky earthquake. The purpose this study was to assess the feasibility of using GPS measurements on routine basis for effective monitoring of strong Kamchatka earthquakes in the area of Petropavlovsk-Kamchatsky. The Zhupanovsky earthquake active phase was chosen as a "test" time interval for comparing GPS and borehole monitoring data. This earthquake has been the strongest seismic event since 2000 in terms of the ratio of the earthquake focus length to the hypocentral distance. The time series borehole electromagnetic and geoacoustic data were compared with the dilatation series reflecting the relative changes in the area of a triangle composed of Kamchatka GPS observation network located in the Petropavlovsk geodynamic testing site. The analysis indicates a high degree of consistency in these time series. GPS data obtained during the active phase of the earthquake preparation is agree with the results of mathematical modeling expected values of volumetric strain on the daylight surface on the eve of the earthquake. A joint analysis of borehole and GPS data made it possible to specify the time limits for the stages of change in the stress-strain state of geoenvironment and to resolve ambiguity of interpretation of the electromagnetic and geoacoustic borehole measurement results at the final stage of preparing the Zhupanovsky earthquake.Приводятся результаты сравнительного анализа данных комплексного скважинного мониторинга изменений напряженно-деформированного состояния геосреды и данных GPS-измерений, полученных во временной окрестности сильного близкого Жупановского землетрясения. Целью исследований являлась оценка целесообразности привлечения на постоянной основе данных GPS-измерений для повышения эффективности системы мониторинга процессов подготовки сильных камчатских землетрясений, функционирующей в районе г. Петропавловска-Камчатского. В качестве «тестового» временного интервала для сравнения данных GPS-измерений с результатами комплексного скважинного мониторинга был выбран интервал активной фазы подготовки Жупановского землетрясения – самого сильного с 2000 г. сейсмического события по величине отношения длины очага землетрясения к гипоцентральному расстоянию. В ходе анализа временные ряды данных скважинных электромагнитных и геоакустических измерений в районе Петропавловского геодинамического полигона сравнивались с рядом дилатации, данные которого отражают относительные изменения площади треугольника, составленного из пунктов Камчатской сети GPS-измерений, расположенных в том же районе. Результаты анализа свидетельствуют о высокой степени согласованности указанных временных рядов. Значимость исходных данных GPS-измерений, полученных на интервале активной фазы подготовки землетрясения, подтверждается их совпадением с оценками ожидаемых величин объемных деформаций на дневной поверхности накануне момента землетрясения, полученными по результатам математического моделирования. Совместный анализ данных скважинных и GPS-измерений позволил уточнить временные границы стадий изменений напряженно-деформированного состояния геосреды, а также устранить неоднозначность в интерпретации результатов электромагнитных и геоакустических скважинных измерений на заключительных стадиях подготовки Жупановского землетрясения

Chemokine Homeostasis in Healthy Volunteers and during Pancreatic and Colorectal Tumor Growth in Murine Models

Chemokines are involved in the humoral regulation of body homeostasis. Changes in the blood level of chemokines were found in cancer, atherosclerosis, diabetes, and other systemic diseases. It is essential to distinguish the effects of co-morbid pathologies and cancer on the level of chemokines in the blood. We aimed to analyze, by multiplex cytometry, the levels of chemokines in the blood of healthy young volunteers as well as of intact mice and mice with CT26 colon and Pan02 pancreatic tumors. Two types of chemokines were identified both in human and murine plasmas: homeostatic ones, which were found in high concentrations (>100 pg/mL), and inducible ones, which can be undetectable or determined at very low levels (0–100 pg/mL). There was a high variability in the chemokine levels, both in healthy humans and mice. To analyze chemokine levels during tumor growth, C57BL/6 and BALB/c were inoculated with Pan02 or CT26 tumor cells, accordingly. The tumors significantly differed in the growth and the mortality of mice. However, the blood chemokine levels did not change in tumor-bearing mice until the very late stages. Taken collectively, blood chemokine level is highly variable and reflects in situ homeostasis. Care should be taken when considering chemokines as prognostic parameters or therapeutic targets in cancer