Mitochondrial respiration inhibition after exposure to UWB pulses as a possible mechanism of antitumor action

The respiration of isolated mice liver mitochondria after exposure to nanosecond UWB pulses (0.15 – 36 kV/cm, 0.6 – 1.0 GHz centre frequency, 3 – 20 ns pulse duration) has been investigated. The respiratory control (RC, the ratio of oxygen consumption) was estimated. The possibility of mitochondrial membrane electroporation was detected as the decrease in the electrical resistance, according to the β-dispersion of the electric current. The monotonous decrease of RC after 1000 UWB pulses from 0.15 kV/cm was observed, the ohmic resistance of mitochondria suspension was reduced. The obtained data indicate the inhibitory effect of UWB pulses on a state of irradiated mitochondria and its membrane

Effect of nanosecond repetitive pulsed microwave exposure on proliferation of bone marrow cells

The purpose was to study the proliferative activity of bone marrow mononuclear cells (BMNCs) of rats after irradiated by nanosecond repetitive pulsed microwave (RPM). It was found that the irradiated by nanosecond microwave pulses can affect the BMNCs proliferation in vitro. It is important that both stimulation and inhibition of proliferation were observed after exposure. The effect depended on the pulse repetition frequency. The amount of BMNCs increased after exposure to pulse repetition frequency of 13 Hz up to 30% in comparison with a control cells and up to 51% in comparison with a falseirradiated cells. In contrast, there was inhibition up to 40% of BMNCs after exposure to a frequency of 8 Hz, in comparison with a control group

Application of repetitively pulsed X-ray radiation in experimental oncology

Development of new technologies in the field of radiation required new approaches and strategies for their application. Power radiation when one continued pulsed divided to serial pulses with different specific repetition rate could provide more complicated and expressed reaction of the biological objects. We used different normal and tumor cell lines in vivo and in vitro to compare efficacy of different pulse repetition rate of X-ray radiation when the total absorbed dose didn’t exceed 1 Gy. We observed strong dependent of tumor cell reaction to repetition rate. Using this parameter we can stimulate or inhibit tumor growth up to 90% compare to control group. Irradiation of tumor-bearing mice inhibited growth of primary tumor up to 60% with the total absorbed dose 0.4 Gy. Moreover same experimental conditions allowed to reduce number of metastasis in mouse lung at 70%. That resulted in longer survival of experimental animals compare to control group. Thus we can conclude that pulsed radiation with nanosecond pulse duration has a potential for application in oncology

Different sensitivity of normal and tumor cells to pulsed radiofrequency exposure

The effect of nanosecond radiofrequency pulses (nsRF) on tumor and normal cells has been studied. To determine the viability of cells, an MTT test was used, as well as a real time system for analyzing cell cultures-iCELLigence. It has been shown that ns RF pulses under certain combinations of operating conditions reduce cell proliferation of both tumor and normal cells. Double exposure to 1000 pulses leads to the most effective inhibition of tumor cell proliferation and was 40% after 5 days. Inhibition of the proliferative activity of normal cells was 10% and was maximum after 3 days, then cell growth resumed. The results obtained allow to consider ns RF pulses with different parameters as a promising effective factor for controlling cellular processes for biomedical purposes

Macrophage and tumor cell responses to repetitive pulsed X-ray radiation

To study a response of tumor cells and macrophages to the repetitive pulsed low-dose X-ray radiation. Methods. Tumor growth and lung metastasis of mice with an injected Lewis lung carcinoma were analysed, using C57Bl6. Monocytes were isolated from a human blood, using CD14+ magnetic beads. IL6, IL1-betta, and TNF-alpha were determined by ELISA. For macrophage phenotyping, a confocal microscopy was applied. "Sinus-150" was used for the generation of pulsed X-ray radiation (the absorbed dose was below 0.1 Gy, the pulse repetition frequency was 10 pulse/sec). The irradiation of mice by 0.1 Gy pulsed X-rays significantly inhibited the growth of primary tumor and reduced the number of metastatic colonies in the lung. Furthermore, the changes in macrophage phenotype and cytokine secretion were observed after repetitive pulsed X-ray radiation. Conclusion. Macrophages and tumor cells had a different response to a low-dose pulsed X-ray radiation. An activation of the immune system through changes of a macrophage phenotype can result in a significant antitumor effect of the low-dose repetitive pulsed X-ray radiation

C-fos expression and cell proliferation in mice after exposure to nanosecond repetitively-pulsed X-rays

В статье указано Rostov, Vladimir V

Coherent summation of emission from relativistic Cherenkov sources as a way of production of extremely high-intensity microwave pulses

For relativistic Cherenkov devices, we investigate the process of high-power microwave pulse generation with its phase correlating to the sharp edge of an e-beam current pulse. Our theoretical consideration is referred to quasi-stationary and superradiative (SR) generation regimes when spontaneous emission of the e-beam edge serves as the seed for the development of further coherent oscillations. Phase correlation of the excited microwave pulses with the characteristics of the current pulse front and/or an initial external electromagnetic pulse has been additionally confirmed by particle-in-cell simulations. Pulse-to-pulse stability of the radiation phase within several percents of the oscillation period makes it possible to arrange multichannel schemes producing mutually coherent microwave pulses. In the experiments that have been carried out, the cathodes of independent generators were powered by identical accelerating pulses from strictly synchronized voltage modulators, or by splitting the pulse from a single powerful modulator. For the 2-ns regime with the power of each Ka-band backward-wave oscillator about 100 MW, we demonstrate quadratic growth of the power density in the interference maximum of the directional diagram. In a short pulse SR regime, with the peak power of 600 MW in a single channel, for a four-channel 2-D array, we attained a 16-fold radiation intensity gain

Generation of electromagnetic fields of extremely high intensity by coherent summation of Cherenkov superradiance pulses

We demonstrate both theoretically and experimentally the possibility of correlating the phase of a Cherenkov superradiance (SR) pulse to the sharp edge of a current pulse, when spontaneous emission of the electron bunch edge serves as the seed for SR processes. By division of the driving voltage pulse across several parallel channels equipped with independent cathodes we can synchronize several SR sources to arrange a two-dimensional array. In the experiments carried out, coherent summation of radiation from four independent 8-mm wavelength band SR generators with peak power 600 MW results in the interference maximum of the directional diagram with an intensity that is equivalent to radiation from a single source with a power of 10 GW

Климатические изменения термических условий Карского моря за последние 40 лет

The paper discusses air (Ta) and sea surface temperature (SST) year-to-year variability due to warming of the Kara Sea, using the data from regular observations at the meteorological stations Roshydromet (GMS) in 1978–2017, NOAA optimum interpolation and reanalysis data. We use the methods of cluster, correlation analysis and Empirical Orthogonal Functions (EOF). We investigate possible cause and effect relationships of these changes with the variations of the wind field components, climatic indices and the sea ice concentration field. The cluster analysis of the three main EOF components has allowed us to identify four areas on the basis of the nature of changes of the water temperature anomalies field. The climatic changes in these areas, in the coastal and island zones of the Kara Sea have manifested themselves in the steady increase of the annual air temperature at GMS from 0,47–0,77 °C/10 years on the southwest coast to 1,33–1,49 °C/10 years in the north of the sea. This is equivalent to warming from 1,9 to 6,0 °C in the last 40 years. For the open sea the value of the Ta trend is about 1,22 °C/10 years, which corresponds to an increase in the average Ta by 4,9 °C in the last 40 years. This value is approximately 3 times greater than that for all the Northern hemisphere for the same period.Annualy, the maximal trend was observed in November and April mainly and exceeded 2–3 °C/10 years at some of the stations. We identify anomalously warm (2016 and 2012) and anomalously cold (1978, 1979, 1992 and 1998) years: the warmest year was 2012, the coldest — 1979. Positive SST trends were observed over all the sea area during the warm period of year (to 1 °C/10 years). SST increased to 2,4 °C, which is approximately 1,5 times greater than the corresponding SST values for the Northern hemisphere. The maximum SST trend (0,4 °C/10 years) was observed in the northwest and southwest parts of the sea. From June to August the trends of SST exceed the annual ones 1,5–2 times. Interannual SST and Ta variations are characterized by close correlation links. Until approximately 1998–2004 the warming was rather insignificant, and after that the growth rate of Ta and SST increased many fold. Apparently it indicates changes in the mode and the large-scale atmospheric circulation in the early 2000s. We also observed a trend of strengthening of the southern wind during the cold period of the year and the northern one — in the warm period (0,5–0,6 m/s in 40 years). It is shown that there is a close correlation between the Ta increase and the changes in the meridional component of the wind speed during the cold period of the year for all the sea areas. For the warm period it is statistically insignificant both for Ta and SST. For the cold season we observed a contribution of the large-scale mode of atmospheric circulation into the variability of V component of the wind speed. The conribution was expressed through the indeces NAO, SCAND, Pol/EUR, AZOR, ISL and the differences of ISLSIB. For the warm season this contribution is expressed through the NAO, SCAND and AO only. For the warm period we showed statistically significant correlation between the increase in SST, Ta and the processes parametrized by the AMO, EA/WR and AZOR indeces. For the cold period the indeces are AMO, Pol/Eur, SIB and ISL SIB. The interannual variations of the sea ice concentration field are characterized by close correlation with Ta changes both in the annual cycle and during the periods of ice cover formation and evolution (R = –0,7... –0,9). For these periods we showed statistically significant relationships between the first EOF mode fluctuations and two climatic indeces — AMO (R = 0,5) and Pol/Eur (R = 0,4). The relationships between the temporary variability of the sea ice concentration and the wind field characteristics are weaker and statistically significant only for the meridional component of the wind speed (R = –0,4).По данным срочных наблюдений на гидрометеорологических станциях Росгидромета за 1978–2017 гг., данных оптимальной интерполяции и реанализа NOAA выполнен анализ межгодовой изменчивости поверхностной температуры воды и воздуха в Карском море на современном этапе потепления климата. Методы кластерного, корреляционного анализа и аппарата эмпирических ортогональных функций использованы для определения пространственно-временной структуры поля температуры и районирования акватории по особенностям климатических изменений. Исследованы возможные причинно-следственные связи этих изменений с вариациями составляющих поля ветра, климатическими индексами и сплоченностью льда. В результате удалось уточнить количественную оценку тенденций и выявить региональные особенностей межгодовой изменчивости термических условий Карского моря