Ne Laser Irradiation Research Articles

The Effects of Low-Level Helium–Neon (He–Ne) Laser Irradiation on Lipids and Fatty Acids, and the Activity of Energetic Metabolism Enzymes and Proteome in the Blastula Stage and Underyearlings of the Atlantic Salmon Salmo salar: A Novel Approach in Salmonid Restoration Procedures in the North

The effect of He–Ne laser irradiation on fishery parameters as well as on biochemical state, including the lipids and fatty acids, the activity of energy metabolism enzymes and the proteome in the blastula stage and in underyearlings of wild Atlantic salmon after irradiation at the cleavage stage/early blastula (considered as the stages when the cell has a high potential for differentiation) was studied. Low mortality rates of eggs were determined during embryogenesis, as well as increased weight gain and lower morality rates of underyearlings in the experimental group. This is confirmed by changes in a number of interrelated indicators of lipid metabolism: a decrease in total lipids content, including diacylglycerols, triacylglycerols, cholesterol esters, and the phospholipids content remained unchanged. The embryos in the blastula stage (experimental group) had higher aerobic capacity and an increase in pentose phosphate pathway activity. The proteome profiles of eggs in the blastula stage were 131 proteins, of which 48 were significantly identified. The major protein was found to be phosvitin. The proteomes of underyearlings were represented by 2018 proteins, of which 49 were unique for the control and 39 for the experimental group. He–Ne laser irradiation had a strong effect on the contents of histone proteins.

Third-order optical nonlinearity of DSR13/THF solutions under CW He–Ne laser irradiation using Z-scan method

The Z-scan technique was employed to explore the third-order nonlinear optical properties of disperse red 13 organic chromophore solutions in tetrahydrofuran. A continuous-wave He–Ne laser (632.8 nm) was used as a source of irradiation. The nonlinear absorption and nonlinear refractive index coefficients of this dye were investigated. The results showed that this dye has a good nonlinear response with its real and imaginary quantities of third-order susceptibility. The solutions showed negative nonlinear refraction. The best obtained value of the third-order susceptibility was 6.37 × 10–3 esu at a dye concentration of 3.15 × 10–4 mol/L. Moreover, the nonlinear optical properties were enhanced with higher dye concentrations, and an elevated trend in nonlinear absorption and nonlinear refractive index coefficients was observed. Also, it was found that the reverse saturable absorption was the main mechanism responsible for the two-photon absorption effect in DSR13/THF samples.

Quantitative Determination of the Effects of He–Ne Laser Irradiation on Seed Thermodynamics, Germination Attributes and Metabolites of Safflower (Carthamus tinctorius L.) in Relation with the Activities of Germination Enzymes

The present investigation was undertaken to assess the effects of different doses (100, 300, and 500 mJ) of low power He–Ne laser (632.8 nm) irradiation on seed germination and thermodynamics attributes and activities of potential germinating enzymes in relation with changes in seed metabolites. He–Ne laser seed irradiation increased the amylase (Amy), protease (Pro) and glucosidase (Gluco) activities, with a significant improvement in seed thermodynamics and seed germination attributes. A fast increase was found in free fatty acids (FFA), free amino acids (FAA), chlorophyll (Chl), carotenoids (Car), total soluble sugars (TSS) and reducing sugars (RS) in laser treated seeds in parallel with fast decline in seed oil contents and total soluble proteins (TSP). Significant positive correlations were recorded in laser-induced enhanced seed energy levels, germination, activities of germination enzymes with levels of FAA, FFA, Chl, TSS and RS, but a negative correlation with the levels of TSP and oil. In conclusion, the seed treatment with 100 and 300 mJ He–Ne laser was more effective to improve the seed germination potential associated with an improvement in seed energy levels due to increased activities of germination enzymes due to the speedy breakdown of seed reserves to simple metabolites as building blocks.

Sensitivity improvement of infrared imaging video bolometer for divertor plasma measurement

The sensitivity of an infrared imaging video bolometer (IRVB) was improved for the measurement of relatively low energy plasma radiation from the viewpoint of the metal foil absorber material. The photon energy of the radiation was considered up to 1 keV for the divertor plasma measurement. The thickness of the foil absorber was evaluated not only for conventional heavy elements, e.g., platinum, but also for light elements by the relation between the photon energy and attenuation length and by mechanical strength. A heat-transfer calculation using ANSYS suggested that light elements with practical foil thickness provide a higher temperature rise of the foil absorber compared with heavier elements with practical foil thickness. The maximum of the temperature rise was evaluated using He-Ne laser irradiation onto absorber samples. The material dependence of the temperature rise has a similar tendency between calculations and experiments. Experimentally, the sensitivity of the IRVB improved from 280 to 110 µW/cm2 using titanium with 1 µm thickness compared with conventional platinum with 2.5 µm thickness. Consequently, the signal-to-noise ratio of the IRVB could be improved from 2.8 to 9.1.

Influence of Pulsed He-Ne Laser Irradiation on the Red Blood Cell Interaction Studied by Optical Tweezers.

Optical Tweezers (OT), as a revolutionary innovation in laser physics, has been extremely useful in studying cell interaction dynamics at a single-cell level. The reversible aggregation process of red blood cells (RBCs) has an important influence on blood rheological properties, but the underlying mechanism has not been fully understood. The regulating effects of low-level laser irradiation on blood rheological properties have been reported. However, the influence of pulsed laser irradiation, and the origin of laser irradiation effects on the interaction between RBCs remain unclear. In this study, RBC interaction was assessed in detail with OT. The effects of both continuous and pulsed low-level He–Ne laser irradiation on RBC aggregation was investigated within a short irradiation period (up to 300 s). The results indicate stronger intercellular interaction between RBCs in the enforced disaggregation process, and both the cell contact time and the initial contact area between two RBCs showed an impact on the measured disaggregation force. Meanwhile, the RBC aggregation force that was independent to measurement conditions decreased after a short time of pulsed He–Ne laser irradiation. These results provide new insights into the understanding of the RBC interaction mechanism and laser irradiation effects on blood properties.

The Effect of Fluence on Macrophage Kinetics, Oxidative Stress, and Wound Closure Using Real-Time In Vivo Imaging.

Objective: The aim of our study was to quantify the effect of doses delivered by a He:Ne laser on individual macrophage kinetics, tissue oxidative stress, and wound closure using real-time in vivo imaging. Background: Photobiomodulation has been reported to reduce tissue inflammation and accelerate wound closure; however, precise parameters of laser settings to optimize macrophage behavior have not been established. We hypothesized that quantitative and real-time in vivo imaging could identify optimal fluence for macrophage migration, reduction of reactive oxygen species, and acceleration of wound closure. Methods: Larval zebrafish Tg(mpeg-dendra2) were loaded with dihydroethidium for oxidative stress detection. Fish were caudal fin injured, treated with 635 nm continuous 5 mW He:Ne laser irradiation at 3, 9, or 18 J/cm2 and time-lapsed imaged within the first 120 min postinjury. Images taken 1 and 24-h postinjury were compared for percentage wound closure. Results: A fluence of 3 J/cm2 demonstrated significant increases in macrophage migration speed, fewer stops along the way, and greatest directed migration toward the wound. These findings were associated with a significant reduction in wound content reactive oxygen species when compared with control wounded fins. Both 3 and 9 J/cm2 significantly accelerated wound closure when compared with nonirradiated control fish. Conclusions: Wound macrophage activity could be manipulated by applied fluence, leading to reduced levels of wound reactive oxygen species and accelerated wound closure. The zebrafish model provides a means to quantitatively compare wound macrophage behavior in response to a variety of laser treatment parameters in real time.

Effects of He–Ne laser and argon laser irradiation on growth, germination, and physico-biochemical characteristics of wheat seeds (Triticumaestivum L.)

Wheat seeds (Triticumaestivum L.) were exposed to two different types of lasers, a He–Ne laser (633 nm) and an argon laser (514.5 nm), to study their effects on growth, germination, and physiological and biochemical characteristics such as the amounts of chlorophyll a, chlorophyll b, and carotenoids. A significant increase in the growth characteristics was monitored and studied keeping in view the length as well as fresh and dry weight of shoots and roots. Similarly, plant pigment contents such as chlorophyll a, chlorophyll b, and carotenoids were significantly changed. These significant alterations led to an increase in growth and germination compared with unexposed (control) wheat seeds. The experimental results of this in vitro study clearly demonstrate that different lasers like He–Ne laser and argon laser at low power significantly enhance the growth and germination of wheat seeds (Triticumaestivum L.) by positively influencing its physiological and biochemical characteristics.

He–Ne laser acupuncture for 30 cases of unilateral nervous tinnitus

ObjectiveTo observe the clinical effects of the unilateral nervous tinnitus treated by He–Ne laser acupuncture. MethodsA total of 30 patients of unilateral nervous tinnitus were treated with He–Ne laser acupuncture. The disposable filiform needles of 0.40 mm × 25 mm were used. Ĕrmén (耳门 TE 21), Tīnggōng (听宫 SI 19), Tīnghuì (听会 GB 2), Yìfēng (翳风 TE 17), Shuàigŭ (率谷 GB 8) and Zhōngzhŭ (中渚 TE 3) were adopted on the affected side. The input and output ends of the fiber-optic catheter of the laser instrument were connected at a pair of acupoints (TE 21 connect to SI 19, GB 2 connect to TE 17, GB 8 connect to TE 3). Each pair of acupoints was stimulated with He–Ne laser irradiation for 10 min, 8–10 mW in the output power and 6328 Å in the wavelength. The needles were retained for 30 min totally. The treatment was given once a day, 5 times a week, continuously for 2 weeks. ResultsOf 30 cases, 19 cases were cured clinically, accounting for 63.3% (19/30); 7 cases effective remarkably, accounting for 23.3% (7/30) and 4 cases failed, accounting for 13.3% (4/30). ConclusionHe–Ne laser acupuncture achieves the satisfactory effects on treating nervous tinnitus and it is easily accepted by the patients. Hence, this therapy deserves to be promoted in clinical application.

Influence of low-intensity laser radiation on the dynamics of some phytohormone content in the callus tissues of wheat Triticum aestivum L.

We carried out an analysis of the influence of low-intensity He–Ne laser radiation on the dynamics of changes observed in the content of the phytohormones abscisic, jasmonic, salicylic, and indoleacetic acids in wheat calluses of Triticum aestivum L. using chromatography–mass spectrometry. He–Ne laser irradiation (λ = 632.8 nm) in its stimulant dose (3.5 J cm−2) was proved to cause a decrease in jasmonic and indoleacetic acid content and, simultaneously, a significant (2.5–3 times) increase in ‘stress’ abscisic and salicylic acids. The response of jasmonic acid to He–Cd laser irradiation (λ = 441 nm) was specific, which is probably due to the blue-light-induced biosynthesis of the acid. This article discusses a possible connection between substantial changes in growth regulator content within the plant tissue under the influence of low-intensity laser irradiation and the stress character of this type of radiation.

Narrow bandgap mid-infrared photodetectors based on InAsSbP quantum dots

The results of investigations of mid-infrared photodetectors based on InAsSbP quantum dot (QD) grown on InAs(100) substrate by modified liquid phase epitaxy are presented. The atomic force microscope measurements have shown that the surface density of grown QDs is (4–8) × 109 cm−2. Also, the morphology and crystalline quality of grown QDs are investigated by a scanning tunneling microscope. Photodetectors based on n-InAs(100) substrate with InAsSbP QDs on its surface were fabricated in the form of a photoconductor cell. The photoresponse spectrum extended up to 4 μm was observed. The optical properties of fabricated structures were investigated under He–Ne laser irradiation with wavelength of 1.15 μm. It was found that the relative surface conductance increases by 16% at power density of 0.15 W/cm2. Capacitance hysteresis with maximal remnant capacitance of 2.17 nF at 103 Hz was observed as well.

Inhibition Effect of a Laser on Thickness Increase of p-Type Porous Silicon in Electrochemical Anodizing

We demonstrate that the thickness increase of the porous layer on p-type (1–10 ohm-cm) silicon can be inhibited from hundreds to several nm/min in regular anodizing by exposure to He–Ne laser irradiation. During 2.0 mW laser irradiation, the growth in thickness was reduced to 5–6 nm/minute by anodizing with a current density of 10 mA/cm2. The inhibition effect on the thickness increase of porous silicon depends significantly on the laser power during a fixed anodizing time.

Effects of He–Ne laser on Daphnia magna Straus manifested in subsequent generations

The effects of He–Ne laser irradiation (including visible laser light 632.8 nm in wavelength and an attendant electromagnetic field from the laser apparatus) on the fertility, newborn quality and linear dimensions of the body of Cladocera Daphnia magna Straus were determined. It is shown that the attendant electromagnetic field generated by the laser apparatus can have significant impact on the results of low-intensity laser therapy. The laser light exposure of daphnia to a dose range of 1.7–1300 mJ cm−2 stimulates the integral functions of the daphnia’s body. At the same time, the attendant electromagnetic field (72 mA m−1 in the frequency range of 0.02–20 kHz and 400 mA m−1 in the frequency range of 3–4 MHz) causes the appearance of quickly dying and/or abnormal newborn (up to a small percent) that has never been observed in the control. Anomalies of daphnia mainly consisted of swimming antenna pathologies. Moreover, under the influence of the attendant electromagnetic field on parental daphnia only, these anomalies appear even in several subsequent generations of newborn. The negative impact on daphnia disappears completely after the suppression of the attendant electromagnetic field to laboratory background level. It is shown that laser light can partially compensate the negative impact of the attendant electromagnetic field on Daphnia.

Photodecomposition, photomutagenicity and photocytotoxicity of retinyl palmitate under He–Ne laser photoirradiation and its effects on photodynamic therapy of cancer cells in vitro

ObjectiveOur aim was to study photodecomposition, photomutagenicity and cytotoxicity of retinyl palmitate (RP), a principal storage form of vitamin A in humans and animals, under He–Ne laser photoirradiation. Moreover, the effect of different concentrations and timing protocol of antioxidants on photodynamic therapy (PDT) is contradictory, so the effect of RP (as antioxidant) on the PDT cytotoxicity was studied. MethodsPhotomutagenicity was tested by Ames test. Photodecomposition was studied by UV–vis spectroscopy. Cytotoxicity was measured with MTT-assay. Moreover, the effect of PDT, using hematoporphyrin derivatives (HpD) as photosensitizer under He–Ne laser irradiation (10J/cm2), was studied on HeLa cells either with or without RP (1–100μM) which incubated with the cells for short or long incubation period (1h or 24h) prior to PDT. ResultsNo photodecomposition of RP alone was obseved whereas there is a little photodecomposition of RP only in presence of HpD under irradiation with He–Ne laser. Moreover, no photomutagenicity was observed in Salmonella typhimurium strains under laser irradiation in presence or absence of HpD. RP alone (1–100μM) significantly decrease the viability of HeLa cells. Laser irradiation of HeLa cells pre-incubated with RP alone for 24h showed further significant decrease in viability of the cells. While RP incubations for 1h before PDT had slight effect on the cells, 24h incubation before PDT enhanced the cytotoxicity of PDT on HeLa cells. ConclusionsRP can be used 24h before PDT to enhance its effects. RP is not mutagenic under irradiation with He–Ne laser.

The effect of (He–Ne) laser irradiation on the optical properties of methyl orange doped PVA films

The effect of (He–Ne) laser irradiation for different irradiant times on optical properties of (10 ml) methyl orange doped PVA films were investigated. The films were prepared by casting method. Absorption and transmission spectra for all samples were measured by UV-Visible spectrophotometer. All optical constants affected by laser irradiation such as refraction index, extinction coefficient, complex dielectric constants, and optical energy gap which decreased with increasing irradiation times.

ZnO Nanofertilizer and He Ne Laser Irradiation for Promoting Growth and Yield of Sweet Basil Plant

This study was conducted to evaluate the effectiveness of zinc nanofertilizer strategy on sweet basil yield, through alone application or combined with pre-sowing laser irradiation. Furthermore, evaluate the growth of plant and the level of active essential oil constituents. Zinc oxide (ZnO) nanoparticles (NPs) were synthesized, and transmission electron microscope revealed particle size of approximately 10.5-15.5 nm. ZnO NPs were applied to sweet basil plants by foliar spray at varying concentrations (10, 20 and 30 mg/L); He Ne laser of power 3mW was used for red light irradiation of sweet basil seeds for 2 min. exposure time. Total chlorophyll, total carbohydrate, essential oil levels, zinc content, plant height, branches/plant and fresh weight were measured. In general, the combined foliar spray application of ZnO nanofertilizer with pre-sowing He Ne laser irradiation showed more effectiveness than ZnO nanofertilizer alone and 20mg/L concentration gave the highest results of all measured traits. Statistical analysis (t-test) showed significant differences among the effects of the various concentrations of zinc oxide NPs on these attributes. The results showed an inverse relationship between the total carbohydrate content and the percentage of essential oil in the leaves. Together these findings support the usefulness and effectiveness of zinc oxide nanofertilizer and laser irradiation treatment to enhance the growth and yield of sweet basil plants. The article presents some promising patents on ZnO nanofertilizer and He Ne laser irradiation.

Synthesis of composite Au/TiO2 nanoparticles through pulsed laser ablation and study of their optical properties

This paper is a report on the synthesis of composite Au/TiO2 nanoparticles (NPs) using a novel and chemically clean method by ablating a gold target immersed in colloidal TiO2 NPs using 1064 nm Nd:YAG laser pulses. Further, the NPs were characterized through ultraviolet–visible spectroscopy, transmission electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. In addition, the nonlinear optical response of the synthesized samples was studied under continuous wave He–Ne laser irradiation.

Thermally induced nonlinear optical response and optical power limiting of acid blue 40 dye

We report the investigations of thermally induced third-order nonlinear optical and optical limiting characterizations for various concentrations of acid blue 40 dye in N,N-Dimethyl Formamide, studied by employing z-scan technique under cw He–Ne laser irradiation at 633 nm wavelength. The samples exhibited nonlinear absorption and nonlinear refraction under the experimental conditions. For lower concentration, the samples display both saturable absorption (SA) and reverse saturable absorption (RSA); whereas with increase in concentration, RSA behaviour prevails. The estimated values of the effective coefficients of nonlinear absorption βeff, nonlinear refraction n2 and third-order nonlinear susceptibility χ(3) were found to be of the order of 10−2 cm/W, 10−4 esu and 10−6 esu respectively. Multiple diffraction rings were observed when the samples were exposed to laser beam due to refractive index change and thermal lensing. The effect of concentration and the laser intensity on the self-diffraction ring patterns was studied experimentally. The acid blue 40 dye also exhibited strong optical limiting properties under cw excitation and reverse saturable absorption is found to be the dominant nonlinear optical process leading to the observed nonlinear behaviour.

He–Ne laser-induced changes in germination, thermodynamic parameters, internal energy, enzyme activities and physiological attributes of wheat during germination and early growth

Using low power continuous wave He–Ne laser irradiation of seeds, the germination characteristics, thermodynamic changes and enzyme activities as well as changes in morphological attributes were explored for wheat (Triticum aestivum L. cv. S-24) cultivar. The changes in thermodynamic properties such as change in enthalpy (ΔH), entropy generation [(ΔSe)], entropy flux [(ΔSc)], entropy generation ratio [(ΔS)e/Δt], and entropy flux ratio [(ΔS)c/Δt] showed significant (P < 0.05) changes at an energy level of 500 mJ. The germination energy (GE), germination percentage (G%), germination index (GI) as well as α-amylase and protease activities was also found to be higher at 500 mJ, while the mean emergence time (MET) and time for 50% germination (E50) decreased for 300 mJ irradiance. The internal energy of the seeds increased significantly at all laser energy levels, but was highest for 500 mJ 72 h after sowing. The enzyme activities increased up to 24 h after sowing and then declined. The activities of α-amylase and protease were found to be positively correlated with the plant physiological attributes. These results indicate that low power continuous wave He–Ne laser (632 nm) treatment has considerable biological effects on seed metabolism during germination as well as on later vegetative growth.

Effect of annealing on the structural and nonlinear optical properties of ZnO thin films under cw regime

We report on the studies of the effects of annealing on the structural and third-order nonlinear optical properties of ZnO thin films deposited on quartz substrates by the RF magnetron sputtering technique. The films were annealed in the temperature range 400–1000 °C. The third-order nonlinear optical studies were carried out using the z-scan technique under continuous wave (cw) He–Ne laser irradiation at 633 nm wavelength. The effects of annealing on the structural properties were examined using x-ray diffraction and atomic force microscopy (AFM). The (0 0 2) preferred orientation increased with increase in annealing temperature up to 800 °C. The crystalline phases of SiO2 were observed at higher annealing temperatures. The appearance of an extraneous phase was confirmed by AFM images and optical transmittance spectra. The samples exhibited nonlinear absorption and nonlinear refraction under the experimental conditions. The negative sign of the nonlinear refractive index n2 indicated that the films exhibit self-defocusing property due to thermal nonlinearity. The nonlinear refractive index n2, the nonlinear absorption coefficient βeff and the third-order optical susceptibility χ(3) were found to be of the highest orders. The estimated value of third-order optical susceptibility χ(3) was of the order of 10−3 esu. Multiple diffraction rings were observed when the samples were exposed to the laser beam. The appearance of rings was due to the refractive index change and thermal lensing. With increase in laser intensity, the variations of the self-diffraction ring patterns were studied experimentally. The films also exhibited strong optical limiting properties under cw laser excitation, and reverse saturable absorption was the dominant process leading to the observed nonlinear behaviour.

Histological changes in adult rat pancreas upon chronic administration of aspartame

Background and aim Low-level laser irradiation (LLLI) has been shown to modulate the proliferation of endothelial cells. Helium–neon (He–Ne) laser is the best type of laser for biostimulation. The aim of the present study was to investigate the direct stimulatory effect of LLLI on the proliferative potential of human umbilical vein endothelial cell line in vitro. Materials and methods This study included five groups: group I (zero time after seeding He–Ne laser irradiation), group II (24▒h after seeding He–Ne laser irradiation), group III (48▒h after seeding He–Ne laser irradiation), group IV (96▒h after seeding He–Ne laser irradiation), and group V (cumulative He–Ne laser irradiation every 48▒h for a period of 6 days). Each group was subdivided into three subgroups: subgroup a (control), subgroup b (1.77▒J/cm2 He–Ne laser irradiation), and subgroup c (3.54▒J/cm2 He–Ne laser irradiation). A continuous wave He–Ne laser, emitting a wavelength of 632.8▒nm with a power output of 5▒mW was used for irradiating the cells. A growth curve was constructed for each group to determine the growth parameters. Results The most efficient cellular response to LLLI was in subgroup Ic depending on the population doublings achieved, followed by subgroup Ib. Therefore, the early the use of He–Ne laser irradiation for the cultured cells, the more the cellular stimulation and proliferation. Meanwhile, their delayed use resulted in less cellular stimulation and proliferation. Moreover, the results showed that 1.77 and 3.54▒J/cm2 of He–Ne laser irradiation were always stimulatory for endothelial cells either significantly or insignificantly. Conclusion The present study showed that 1.77 and 3.54▒J/cm2 of He–Ne laser irradiation stimulated human umbilical vein endothelial cell line proliferation.