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

High-Voltage Drivers Based on Forming Lines with Extended Quasi-Rectangular Pulses for High-Power Microwave Oscillators

The paper considers such modifications of an ordinary pulse-forming line (PFL) as double-width and triple-width forming lines (DWFL, TWFL) built around the PFL by nesting one and two additional uncharged lines, respectively, into its free volume inside the inner conductor of the PFL. The theoretical analysis is supported by simulation and experimental data, showing that the TWFL provides a 3-fold increase in the voltage pulse width and that it can be further increased by an arbitrary integer factor k. The results of the numerical simulations also show the electric field behavior and other features, including the edge effect in the TWFL. The proposed method opens up new opportunities for designing compact high-power microwace (HPM) sources