Low-intensity Radiation Research Articles

Combined Impact of Gamma and Laser Radiation on Peripheral Blood of Rats in vivo

The impact of γ radiation of 137Сs (doses of 1 and 3 Gy), low-intensity laser radiation (λ = 670 nm, 5.3 or 10.6 J/cm2) as well as the influence of consecutive laser and γ radiation on peripheral blood and blood cells (erythrocytes, leukocytes, lymphocytes, granulocytes) were studied by analyzing the number of blood cells, blood absorption spectra, and activity of antioxidant defense enzymes. Two series of experiments were performed on four groups of rats. The rats of the control group (group 1) were not exposed to γ or laser radiation. In the experimental groups, single irradiation of the whole body of rats with γ radiation (group 2), three- or four-day over-vein irradiation of blood in the tail vein by low-intensity laser radiation (group 3), and successive three- or four-day irradiation of blood by laser and then a single irradiation of the whole body with γ radiation (group 4) were performed. It was shown that changes of the blood cell content in the experimental groups are accompanied by changes in the spectral characteristics of the blood and the activity of antioxidant defense enzymes. The radioprotective effect of low-intensity laser radiation is manifested as an increase in the average number of leukocytes and lymphocytes in the group as compared with the postradiation, as well as an increase in the activity of antioxidant protection enzymes. The possibility of using low-intensity optical radiation for correction of hematological disorders caused by ionizing radiation is discussed.

Flat supercontinuum generation pumped by amplified noise-like pulses from a figure-eight erbium-doped fiber laser

The conditions to obtain noise-like pulses (NLPs) from a figure-eight fiber laser (F8L) and their application for supercontinuum (SC) generation in the anomalous dispersion regime are reported. The F8L is designed to remove the undesired low-intensity background radiation from pulse emission, generating NLPs with a 3 dB spectral bandwidth of 17.43 nm at the fundamental repetition frequency of 0.8 MHz. After amplification, NLPs reach a maximum average power of 9.2 mW and 123.32 nm spectral bandwidth. By controlling the amplifier pump power, flat SC generation is demonstrated through both a 800 m long spool of SMF-28 fiber and a piece of 5 m long highly nonlinear optical fiber. The results demonstrate a satisfactory flatness of ~3 dB over a bandwidth of ~1000 nm in the range from 1261 to 2261 nm, achieving to the best of our knowledge, one of the flattest SC generated from noise-like pulses.

Formation of long-lived reactive species of blood serum proteins induced by low-intensity irradiation of helium-neon laser and their involvement in the generation of reactive oxygen species

It was demonstrated that low-intensity radiation of helium-neon (He-Ne) laser at 632.8nm, which leads to the transition of oxygen to a singlet state, causes the formation of reactive oxygen species (ROS) – hydrogen peroxide, hydroxyl and superoxide (hydroperoxide) radicals – in aqueous solutions. The oxygen effect – dependence of hydrogen peroxide formation on the concentration of molecular oxygen – was shown, and the participation of singlet oxygen, hydroxyl radicals and superoxide (hydroperoxide) radicals in this process was testified. Laser radiation-induced ROS in solutions of blood serum proteins, bovine serum albumin and bovine gamma-globulin, cause the formation of long-lived reactive protein species (LRPS) with a half-life of about 4h. The generation of LRPS caused by laser irradiation results in prolonged several-hour generation of ROS – hydrogen peroxide, hydroxyl and superoxide radicals. As affected by LRPS, coupled radical reactions lead to conversion of dissolved molecular oxygen to hydrogen peroxide. Irradiation with light sources away from the oxygen absorption band is not attended by formation of ROS and LRPS. A consideration is provided for the possible molecular mechanisms of ROS formation under the influence of He-Ne laser irradiation, the role of proteins in their generation and the biological significance of these processes.

Transgenerational genomic instability in the first generation offspring of mice exposed to low-intensity red and near-infrared irradiation in vivo

Transgenerational genomic instability in the first generation offspring of mice exposed to lowintensity infrared laser (632.8 nm) and light-emitting-diode infrared irradiation (850 nm) was investigated in vivo. It was found that the level of spontaneous damage in bone marrow according to the micronucleus test, the level of reactive oxygen species in whole blood, and the mass index of lymphoid organs in all of the descendants of irradiated mice did not increase. After additional X-ray exposure of the progeny at a dose rate of 1.5 Gy, a decrease in the level of damage and the absence of an adaptive response were revealed upon testing according to “radiosensitivity” and the radiation-induced adaptive-response scheme (0.1 + 1.5 Gy), respectively, compared to the descendants of nonirradiated mice. The rate of tumor growth in the offspring of irradiated mice did not differ from that in the descendants of nonirradiated mice, although inhibition of the tumor growth rate was observed in their irradiated parents. The survival rate after irradiation at a dose rate of 6.5 Gy did not differ from both the parents and the control.

Relationship between the Contents of Cyclins, Cyclin-Dependent Kinases, and Their Inhibitors in Whole Blood Mononuclear Leukocytes during the Postclinical Stage of Community-Acquired Pneumonia under the Influence of 1-GHz Microwaves.

The contents of cyclins A1, B1, E1, and D1, cyclin-dependent kinases 2 and 4 (CDK2 and CDK4), cyclin-dependent kinase 2C inhibitor (p18), and cyclin-dependent kinase 1C inhibitor (p57) in whole blood mononuclear cells of practically healthy donors and convalescents from community-acquired pneumonia were measured after cell exposure to low-intensity electromagnetic radiation of 1 GHz. The level of cyclins A1, D1, and B1, p57, and p18 proteins, and CDK2 was reduced in convalescents, while the content of cyclin B1 was elevated in both groups. A strong correlation was found between the content of cyclin B1 and the levels of cyclin A1 and CDK2 in convalescents. Single exposure of whole blood cells to 1-GHz microwaves was accompanied by an increase in the content of the analyzed factors (particularly, cyclins A1 and E1). These data indicate that radiation induced activation of the synthetic phase of the cell cycle.

The distinguishing effects of low-intensity electromagnetic radiation of different extremely high frequencies on Enterococcus hirae: growth rate inhibition and scanning electron microscopy analysis.

A stronger inhibitory effect of low-intensity electromagnetic field on Enterococcus hirae ATCC 9790 bacterial growth rate was observed with 53GHz vs 51·8GHz, regardless of exposure duration. Scanning electron microscopy analysis showed that almost all irradiated cells in the population have spherical shapes similar to nonirradiated ones, but they have increased diameters in case of irradiated cells at 53GHz, but not 51·8GHz. The results are novel, showing distinguishing effects of low-intensity electromagnetic field of different frequencies. They could be applied in treatment of food and different products in medicine and veterinary, where E.hirae plays an important role.

The Effect Infrared and Ultraviolet Radiation in the Development of the Cells in the Porous Permeable Titanium Nickel Based Alloy Scaffold

The respond of the cells to electromagnetic radiation depends on many factors, including microenvironment. Different cells exhibit different behavior when exposed to low-intensity radiation employed in the research. The effect of infrared (IR) and ultraviolet (UV) radiation leads to the reliable change in the number of viable cells. Viable cells of Ehrlich tumor, spleen and bone marrow of C57BL/6 mice placed in a porous permeable TiNi-based alloy scaffold were studied. The level of the radiation effect was determined for different types of cells. A comparative analysis of the viable cells cultured in the porous permeable TiNi scaffold was performed.

Correction of Immunoendocrine Disorders in Patients with Ischemic Heart Disease Using Low-intensity Microwave Therapy

The article considers the possibility of correcting immunoendocrine disorders in patients with ischemic heart disease using low-intensity microwave radiation at a frequency of 1 GHz. The study showed that the Aquaton device for low-intensity microwave therapy could be used to stimulate production of bradykinin, NO, IL-24, antioxidants, and soluble tumor necrosis factor-alpha receptor II by whole blood cells. Exposure to microwave irradiation was accompanied by a decrease in the caspase-1 content in mononuclear leukocytes with a simultaneous increase in the nuclear transcription factor NFκB level, promoting thereby normalization of the subclinical inflammatory process and correction of endothelial dysfunction.

Investigation into the mechanisms of X-ray generation during the interaction between relativistic electrons and a medium by means of the Röntgen-1 setup

The Rontgen-1 setup which is intended for use in investigating the spectral-angular characteristics of X-rays generated due to the interaction between a 7-MeV electron beam and substances, including different shaped surfaces, is described. The setup is distinguished by a low radiation background, enabling the determination of low-intensity radiation spectra. The results of measuring the characteristics of the polarized bremsstrahlung of relativistic electrons from media with different atomic structures are presented.

Elimination of continuous-wave component in a figure-eight fiber laser based on a polarization asymmetrical NOLM

The operation of a nonlinear optical loop mirror (NOLM) with polarization-dependent transmission was analyzed to perform high-quality ultrashort optical pulses in a figure-eight fiber laser configuration. The design of the NOLM is based on a symmetrical coupler, a loop of highly twisted low-birefringence fiber and a quarter-wave retarder (QWR) to provide polarization asymmetry. Pedestal-free optical pulses were obtained by careful adjustment of the NOLM low-power transmission, which is easily realized in our setup by rotation of the QWR. The laser is capable of operating in both the conventional soliton and the noise-like pulse regimes. Optical pulses as short as 1.39 ps were observed at the fundamental repetition frequency of 0.8 MHz. The effectiveness of the proposed scheme is demonstrated by the elimination of low-intensity radiation at the laser output.

Impact of Light Intensity on Control in Photoinduced Organocatalyzed Atom Transfer Radical Polymerization.

Organic photoredox catalysts have been shown to operate organocatalyzed atom transfer radical polymerizations (O-ATRP) using visible light as the driving force. In this work, the effect of light intensity from white LEDs was evaluated as an influential factor in control over the polymerization and the production of well-defined polymers. We posit the irradiation conditions control the concentrations of various catalyst states necessary to mediate a controlled radical polymerization. Systematic dimming of white LEDs allowed for consideration of the role of light intensity on the polymerization performance. The general effects of decreased irradiation intensity in photoinduced O-ATRP were investigated through comparing two different organic photoredox catalysts: perylene and an 3,7-di(4-biphenyl) 1-naphthalene-10-phenoxazine. Previous computational efforts have investigated catalyst photophysical and electrochemical characteristics, but the broad and complex effects of varied irradiation intensity as an experimental variable on the mechanism of O-ATRP have not been explored. This work revealed that perylene requires more stringent irradiation conditions to achieve controlled polymer molecular weight growth and produce polymers with dispersities <1.50. In contrast, the 3,7-di(4-biphenyl) 1-naphthalene-10-phenoxazine is more robust, achieving linear polymer molecular weight growth under relative irradiation intensity as low as 25%, to produce polymers with dispersities <1.50. This finding is significant, as the discovery of highly robust catalysts is necessary to allow for the adoption of successful O-ATRP in a wide scope of conditions, including those which necessitate low light intensity irradiation.

Chronobiological approach to managing an exacerbation of chronic recurrent bacterial cystite

To investigate the effects of complex therapy with and without phototherapy for an exacerbation of chronic recurrent bacterial cystitis in women at the peaks of chronobiological activity. The study comprised 60 patients (mean age 30.1+/-5.5 years) with exacerbations of chronic recurrent bacterial cystitis. Patients in the comparison group (n=30) were managed with standard therapy, in the study group (n=30) standard therapy was used concurrently with phototherapy by low-intensity light radiation carried out at the maximum peaks of chronobiological activity. An assessment of the results included estimation of clinical and laboratory outcomes and the chronobiological status of patients in both groups. The study findings showed that phototherapy at the peaks of patients chronobiological activity icombined with standard treatment resulted in a faster reduction of clinical signs of the disease and desynchronosis.

Состояние антиоксидантной защиты в постклиническую фазу внебольничной пневмонии под влиянием низкоинтенсивного микроволнового излучения частотой 1 ггц

Состояние антиоксидантной защиты в постклиническую фазу внебольничной пневмонии под влиянием низкоинтенсивного микроволнового излучения частотой 1 ггц

Waveguide photonic limiters based on topologically protected resonant modes

We propose a concept of chiral photonic limiters utilising topologically protected localised midgap defect states in a photonic waveguide. The chiral symmetry alleviates the effects of structural imperfections and guaranties a high level of resonant transmission for low intensity radiation. At high intensity, the light-induced absorption can suppress the localised modes, along with the resonant transmission. In this case the entire photonic structure becomes highly reflective within a broad frequency range, thus increasing dramatically the damage threshold of the limiter. Here we demonstrate experimentally the principle of operation of such photonic structures using a waveguide consisting of coupled dielectric microwave resonators.

Investigation of the Surface Defects in N-Channel MOS Transistors Under Long-Term Low-Dose-Rate Irradiation

Gamma-radiation is commonly used to study surface defects in MOS transistors. Early experiments show two stages of surface-defect formation in a MOS structure under low-intensity gamma irradiation (Popov &amp; Vin, 2014; Popov, 2016). On the first stage the defect formation take place on interface Si-SiO2 from the oxide side. This process is described by an exponential dependence (Rashkeev et al., 2002). In the second stage “additional” surface defects are formed from the Si side. Radiation defects of silicon migrated to interface Si-SiO2 from the semiconductor.The goal of this paper is investigation of surface-defect formation in a MOS transistor using the changing of surface electron mobility.

Ultrasonic irradiation of low intensity with a mode of sweeping frequency enhances the membrane permeability and cell growth rate of Candida tropicalis

Here we report the enhancement of both cellular permeability and cell growth rate of Candida tropicalis after treatment with the ultrasonic irradiation of low intensity using a mode of sweeping frequency (UILS) generated by a self-developed ultrasonic device in our lab. After the ultrasonic treatment, remarkable biomass enhancement of the yeast was observed; the hyphae became significantly longer; the seeped cellular protein and nucleic acid from the yeast increased and the cellular Ca2+ content became lower. Illumina transcriptome sequencing showed that the ultrasonic treatment affected the expression of genes involved in diverse cellular components, biological processes and molecular functions. RT-PCR and Western blotting further confirmed the up-/down-regulation of genes in the ultrasound-treated yeasts. The optimal conditions of the ultrasonic treatment for the maximum biomass addition were determined as follows: the yeast was treated for 1h at the mid logarithmic phase, the frequency was 28±2kHz and the power density was 120W/L. Under these conditions, the Candida tropicalis biomass increased by 142.5% compared with the untreated yeast.

Ru(II)-Complex-Based DNA Photocleaver Having Intense Absorption in the Phototherapeutic Window.

Ru(II)-complex-based DNA photocleavers have been extensively studied for their potential application in photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT). However, their MLCT absorption maxima are generally shorter than 600 nm, limiting PDT/PACT application severely. In this work, by incorporating a 5-chloro-8-oxyquinolate-based noninnocent ligand into a merocyanine scaffold Cl-7-IVQ, we obtained a new Ru complex of this ligand, [Ru(bpy)2(Cl-7-IVQ)]2+, which has intense absorption in the window 600-700 nm and enables an efficient •OH-mediated DNA photocleavage. This long-wavelength absorption band has a character of MLLCT transition from the hybrid Ru(dπ)-Cl-7-IVQ(π) orbital to the π*(Cl-7-IVQ) orbital and thus a contribution from the ππ* transition of the merocyanine framework, which endows the complex with a molar extinction coefficient as high as 1.73 × 104 M-1 cm-1 at 649 nm and allows for an efficient DNA photocleavage under an irradiation of low intensity. [Ru(bpy)2(Cl-7-IVQ)]2+ represents the first Ru(II)-complex-based DNA photocleaver that has an MLCT absorption maximum above 600 nm and can selectively inactivate E. coli bacterial cells over HeLa cells upon red light irradiation.

Estimation of nonclassical independent Gaussian processes by classical interferometry

We propose classical interferometry with low-intensity thermal radiation for the estimation of nonclassical independent Gaussian processes in material samples. We generally determine the mean square error of the phase-independent parameters of an unknown Gaussian process, considering a noisy source of radiation the phase of which is not locked to the pump of the process. We verify the sufficiency of passive optical elements in the interferometer, active optical elements do not improve the quality of the estimation. We also prove the robustness of the method against the noise and loss in both interferometric channels and the sample. The proposed method is suitable even for the case when a source of radiation sufficient for homodyne detection is not available.

A study of the impacts of low-intensity light irradiation in the red (λmax = 635 nm) and green (λmax = 520 nm) ranges on the proliferative activity and gene expression profiles of MNNG/hos cells and human fetal fibroblasts

It has been shown that a single low-intensity (0.146 mW/cm2) irradiation of a cell culture of human fetal fibroblasts by a red LED (λmax = 635 nm) at a dose of 175.2 mJ/cm2 led to a slight stimulation of culture growth, whereas light irradiation by a green LED (λmax = 520 nm) at the same dose did not alter the proliferative activity of cultured fibroblasts. The growth of transformed MNNG/hos cells did not change at the selected irradiation modes. Both types of irradiation changed the expression profile of the proliferation and osteogenic differentiation genes of the fibroblast culture. In the transformed MNNG/hos cells, the red light promoted the expression of stemness genes, osteogenic differentiation genes, and cell-death markers. The transcription activity of cell-death markers and checkpoints in the MNNG/hos cells increased under the influence of the green light.

The specific features of the development of metabolic and regenerative processes under the action of low-intensity electromagnetic radiation in radiation exposure conditions (an experimental study)

The experiments on male white rats with the use of biochemical, photo-optical, and electron-microscopic techniques have demonstrated that the use of low-intensity electromagnetic radiation of ultrahigh frequency (EMR UHF) and low-intensity low-frequency magnetic field (MF) during the post-irradiation period (within 21 days after exposure to radiation) enhanced the metabolic and regenerative processes in the testes and liver. It was shown that the application of MF largely intensified the antioxidant activity whereas EMR UHF preferentially stimulated the biosynthetic processes as well as the processes of cellular and intracellular regeneration.