Effect Of Laser Irradiation Research Articles

Extended experiment on potable water irradiated with low-intensity laser pen and Solfeggio scale frequencies

In previous article, we reported initial findings based on small experiment on potential use of salt-water as cheap source of renewable battery with various kind of metals as anode and cathode. The purpose of these experiments is to find out which combination of anode and cathode is capable to generate the best performance in terms of electric voltage. Following those previous reports, this writer also conducted several tests to see effect of low-intensity laser irradiation on potable water. While the first series of our experiment clearly indicated possible laser cooling effect of low intensity laser irradiation of potable water and salt water, the following extended experiment on low intensity laser irradiation shows a rather mixed result. In a series of initial experiment, laser irradiation with laser pen gave lower electric potential (down to several minus milli Volt to the Voltmeter reading), but later on after more than 180 sec of irradiation, it shows increased positive milli Volt of electric potential of the system. In this experiment, we found that combination of low-intensity laser irradiation and Solfeggio scale frequencies applied to potable water shows dim result.

Effect of Laser Irradiation on High-Temperature Crystallization Behavior, Oxidation Resistance, and Corrosion Performance Evaluation of Electrodeposited Amorphous Ni-P Coatings

Effect of Laser Irradiation on High-Temperature Crystallization Behavior, Oxidation Resistance, and Corrosion Performance Evaluation of Electrodeposited Amorphous Ni-P Coatings

Hardness and tribological properties of laser irradiated PMMA based nano-microcomposites

In this work, new composite material is manufactured from poly(methyl methacrylate) PMMA matrix reinforced by glass fibre type E-glass. The effect of volume fraction of fibre and length to diameter ratio is studied, and friction and wear characteristics were determined at different volume fractions and fibre sizes. The hardness and wear resistance of randomly distributed PMMA matrix composite were significantly enhanced, and the maximum conditions for reinforcement of PMMA matrix composite to improve tribology characteristics were evaluated. The effect of laser irradiation on the mechanical properties was evaluated by irradiation of composite material after manufacturing, with different kinds of lasers. The continuous wave (CW) argon-ion laser and pulsed Nd:YAG laser were used to irradiate composite material. Hardness, wear rate, and coefficient of friction were evaluated at the same test condition of the unirradiated composite. The significant improvement in improvement in the mechanical properties at certain irradiation conditions was evaluated. Keywords: structure, hardness, wear, PMMA, random distribution.

Effect of laser irradiation on the electrodeposition process, mechanical and corrosion properties of an amorphous Ni P coating

Electrodeposited amorphous alloys require numerous nuclei and irregular atomic arrangements. In this study, the impact of processing parameters (e.g., a nanosecond laser) on the current density in the electroplating solution for an electrodeposited NiP coating was tested using an electrochemical workstation. In addition, the effect of the laser on the temperature and micro-stirring caused by cavitation was simulated using COMSOL (version 5.4). The surface quality, wear, and corrosion resistance of the NiP coating prepared by laser-assisted electrodeposition (LECD) at different laser repetition frequencies (picosecond laser, 0.5, 1, 1.5, 2, and 2.5 MHz) were evaluated. The results showed that the stability of current change was best when the laser frequency, pulse width, scanning line spacing, and irradiation area were 1 MHz, 200 ns, 20 μm, 1 mm2, respectively. Excessive laser energy destroys the balance of electrochemical deposition process. The simulation results showed that the maximum instantaneous temperature of the laser-irradiated solution was 123 °C. Cavitation increases the flow rate of the solution and produces a jet impact on the substrate. The maximum velocity and instantaneous pressure were 0.13 m/s and 7.26 × 108 Pa at 0.1 ns, respectively. At the laser frequency of 0.5 MHz, the P content increases by approximately 2% compared to that of the coating prepared by LECD (1–2.5 MHz). The residual internal stress decreased with increasing frequency, and it existed in the form of tensile stress. The wear and corrosion resistances of the NiP coating were the best when the laser frequency was 1 MHz.

A comparative assessment of the results of the biological response of the oral mucosa on the effect of laser radiation with a wavelength of 445 nm and 810 nm

A comparative assessment of the results of the biological response of the oral mucosa on the effect of laser radiation with a wavelength of 445 nm and 810 nm

Effect of laser radiation on the catalytic activity of amylolytic enzyme preparations of various degrees of purification

Effect of laser radiation on the catalytic activity of amylolytic enzyme preparations of various degrees of purification

Laser Irradiation Effects on Metallic Zinc and its Corrosion Products

Laser Irradiation Effects on Metallic Zinc and its Corrosion Products

Комбинированное действие хронического ионизирующего излучения и многократного лазерного воздействия на когнитивные функции крыс

Low-level laser therapy (LLLT) may have utility in the management of side effects of radiation therapy in head and neck cancer (HNC) patients. Although evidence suggests that LLLT is safe treatment for HNC patients, more research is imperative and vigilance remains warranted to de-tect any potential adverse effects of LLLT on treatment outcomes and survival of HNC patients. The purpose of this study was to evaluate the effect of transcranial low-level laser irradiation (LLLI) in combined with whole-body ionizing radiation (IR) on conditioned-reflex activity of rats. Seventy healthy Wistar female rats were distributed into the following groups: Group 1, sham control; Group 2, LLLI; Group 3, IR; Group 4, IR and LLLI. Group 3 and Group 4 chronically ex-posed to IR (30 days; 5,3+/-0,5 mGy/h; 3,7 Gy). Group 2 and Group 4 received five applications of LLLI, once a day for 15 min (wavelength 890 nm, the pulse duration was 100 ns, impulse fre-quency 10000 Hz, output power – 1,7 mW). Cognitive functions of the rats were tested using shut-tle-box avoidance method. The rats were tested 30 minutes later, 24 hours later, and 14 days af-ter the end of LLLI. LLLI and IR in isolated action (groups 2 and 3) did not significantly affect the conditioned reflex activity of rats. The negative effect of combined exposure to these factors (group 4) on the development and reproduction of an active avoidance reflex within 24 hours af-ter exposure was revealed. Gradually this negative effect weakened and within two weeks was leveled. Thus, the combined action of IR and LLLI may pose a potential danger to the cognitive function of the brain.

Perforation effect of CW laser irradiation on aluminum alloy under subsonic flow

Perforation effect of CW laser irradiation on aluminum alloy under subsonic flow

器官培養したラット下顎頭に対する低出力半導体レーザー光照射の影響

器官培養したラット下顎頭に対する低出力半導体レーザー光照射の影響

A frugal experiment on potential cooling effect of potable water irradiated with laser pen

In previous article, we reported initial findings based on small experiment on potential use of salt- water as cheap source of renewable battery with various kind of metals as anode and cathode. The purpose of these experiments is to find out which combination of anode and cathode is capable to generate the best performance in terms of electric voltage. Following that previous reports, we tried to conduct further simple experiments on possible effect of low intensity laser irradiation on potable water’s electrical features. Nonetheless, this report is slightly disappointing, because as an effect, there is no increase of water electrical feature, instead it may support initial reports by others such as Cohen Tannoudji, Alain Aspect et al, on laser cooling effect to molecules [3][4].

Effect of low intensity laser irradiation on RORC gene expression level in psoriasis patients

<h3></h3> Орфанный ядерный рецептор γ, связанный с рецептором ретиноевой кислоты (<i>RORγ</i>/<i>RORC</i>), контролирует программу экспрессии провоспалительных генов, которая участвует в патогенезе нескольких иммуноопосредованных заболеваний человека, в том числе и псориаза. <h3>ЦЕЛЬ ИССЛЕДОВАНИЯ</h3> Проанализировать экспрессию гена <i>RORC</i> в псориатических бляшках и в не затронутой псориатическим процессом коже тех же больных. Изучить влияние лазерного излучения с длиной волны 1,27 мкм на экспрессию гена <i>RORC</i> в коже больных псориазом. <h3>МАТЕРИАЛ И МЕТОДЫ</h3> <i></i> Работа проводилась на биоптатах кожи, взятых от 12 больных с диагнозом псориаза. Экспрессию гена <i>RORC</i> анализировали методом ПЦР в реальном времени. <h3>РЕЗУЛЬТАТЫ</h3> Экспрессия гена <i>RORC</i> в псориатических бляшках достоверно повышена — в среднем в 8,16±2,06 раза относительно не затронутой псориатическим процессом кожи тех же больных. Наблюдали достоверное снижение экспрессии гена <i>RORC —</i> до 3,21±1,23 раза в псориатических бляшках после лечения больных псориазом лазерным излучением низкой интенсивности. <h3>ЗАКЛЮЧЕНИЕ</h3> Высокая экспрессия гена <i>RORC</i> в псориатических бляшках может указывать на его важную роль в псориатическом процессе, а снижение экспрессии этого гена после воздействия лазерным излучением позволяет использовать его как молекулярный индикатор эффективности лечения.

Influence of diode laser and warm air drying on the shear bond strength of Lithium di-silicate to Dentin. An in-vitro study

Objective: The current study aimed to evaluate the effect of diode laser irradiation (980 nm) and warm air drying(50°C) on shear bond strength between Lithium di-silicate (IPS e.max; Ivoclar) and human dentin using both(Etch &amp; Rinse) adhesive, Adper™ Single Bond 2 (3M ESPE) and (Self-etch) adhesive, Single Bond UniversalTM(3M ESPE) before adhesive polymerization. Material and Methods: 54 sound lower molars were sectioned toobtain flat dentinal surfaces. Specimens were divided into 2 equal groups (n=27): Group 1 (ER) and Group 2(SE) according to bonding approach. Each subgroup was subdivided according to dentin surface treatment into3 equal subgroups (n=9): Control (Co), Diode laser irradiation (L) and Warm air drying (W). All specimenswere adhesively cemented to IPS e.max® CAD discs using RelyX™ Ultimate Clicker™(3M ESPE) resin cement.Samples were then subjected to pre-loading in a thermodynamic manner. All samples were tested for shearbond strength using computer-controlled material testing machine. Data analysis was performed using two-way(ANOVA) (p&lt; 0.05) followed by pair-wise Tukey’s post-hoc tests. Results: In (SE) group, the subgroup (W) hadthe highest shear bond strength values followed by (Co) subgroup and the least was (L) subgroup with statisticallysignificant difference. As for (ER) group, the subgroup (W) had the highest shear bond strength values followedby (Co) subgroup and the least was (L) subgroup with no statistically significant difference. Conclusion: Warmair drying for (SE) bonding approach increased shear bond strength of Lithium di-silicate to human dentin andcan be introduced as a new effective protocol.KEYWORDSAdhesives; Diode laser; IPS e.max; Shear bond strength; Warm air drying.

Changes in the characteristics of semiconductor structures of microwave amplifiers under the action of pulsed laser radiation

The effect of pulsed laser radiation on the change in the parameters of semiconductor structures of field-effect transistors with a Schottky gate with an operating frequency range of 1.5-8 GHz and integrated amplifiers with an operating frequency range of 0.4-6 GHz is studied. Laser radiation with 25 ns pulse duration, incident on the transistor crystal, creates a pulsed photocurrent. It is shown that the amplitude of the pulsed photocurrent is three times higher than the operating transistor current. The current-voltage characteristics of the field-effect transistor were measured in the mode of pulsed laser radiation. The amplitude dependence of the pulsed photocurrent in semiconductor structures on the power of laser radiation for various wavelengths of 1.06 μm and 0.53 μm is studied. It is shown that as a result of the action of pulsed laser radiation on semiconductor structures, a short disappearance of the amplification of the high-frequency signal at the amplifier output occurs. Keywords: laser radiation, transistor, microwave amplifier, photocurrent, current-voltage characteristic.

ПРИМЕНЕНИЕ ИМПУЛЬСНОГО ИНФРАКРАСНОГО НИЗКОИНТЕНСИВНОГО ЛАЗЕРНОГО ИЗЛУЧЕНИЯ В КОМПЛЕКСНОМ ЛЕЧЕНИИ БОЛЬНЫХ С ПОСТИНСУЛЬТНЫМИ КОГНИТИВНЫМИ НАРУШЕНИЯМИ

The results of treatment of 60 patients with a verified diagnosis of ischemic stroke, acute period, with a motor deficit in the form of hemiparesis, with cognitive impairment, are presented; patients were distributed by random sampling into two groups: group 1 (30 people), the standard treatment was supplemented with a course of laser therapy, group 2 (30 people) received only the standard course of treatment. In patients, the effect of low-intensity laser radiation on the cognitive functions, short-term memory, attention, and mental abilities was studied. Efficiency was assessed using the MMSE scale, the Number Memory, Visual Memory Tests, and the method of finding numbers on Schulte Tables. It was found that the inclusion of low-level infrared laser radiation in a standard medical complex reduces the level of cognitive impairment by 2.3 times, increasing short-term memory by 1.6 times, attention by 2.2 times (p &lt; 0.05). In the comparison group, the dynamics of these indicators is significantly lower. The inclusion of pulsed infrared low level laser therapy (LLLT) in the complex rehabilitation of patients with ACVA is a necessary link in neurorehabilitation measures as a method for compensating the impaired brain functions.

ИЗМЕНЕНИЯ ТЕМПЕРАТУРНЫХ ПОЛЕЙ И МИКРОЦИРКУЛЯЦИИ В СТЕНКАХ ПИЛОНИДАЛЬНЫХ КИСТ КОПЧИКОВОЙ ОБЛАСТИ ВО ВРЕМЯ И ПОСЛЕ ЛАЗЕРИНДУЦИРОВАННОЙ ТЕРМОТЕРАПИИ

Introduction. As of today, many options for conservative and surgical treatment of patients with pilonidal cysts have been developed. Our studies on the use of laser radiation in the treatment of epithelial coccygeal passage, which began in 2007, showed its positive clinical effect, which is expressed in a decrease in the number of complications and relapses. The principle of the method is the thermal ablation of the walls of the coccygeal passage with laser radiation. The aim. To study the effect of high-intensity laser radiation on the tissues of pilonidal cyst in patients with epithelial coccygeal passage, in order to improve the results of their treatment. Materials and methods. The study was conducted from 2018 to 2021. The patients were divided into 2 groups depending on the type of surgical treatment. The first group consisted of 124 patients who underwent cyst excision with primary sutures. The second group included 60 patients who underwent laser-induced interstitial thermotherapy. To study microcirculatory changes in the tissues of the pilonidal cyst while doing operational injury, SPECTROTEST (Spectro Analytical Instruments, Germany) spectrometer was used. Results. We have revealed changes in microcirculation and tissue saturation parameters depending on the type of surgical treatment. In the first group, a statistically significant microcirculatory and tissue saturation disorders were found in the walls of postoperative wounds. In the second group, microcirculatory disorders were less pro-nounced, and their normalization occurred much earlier. This indicates the absence of ischemia of the surrounding tissues around the treated area. Temperatures in the walls of pilonidal cysts at laser-induced interstitial thermom-etry vary from 56 to 65 °C, which are the temperatures of destruction of proteins that make up the structure of the cyst walls. On the surface and in the tissues surrounding the cyst, the maximum recorded temperature was 40 °C, and this does not cause protein destruction. Conclusions. High-intensity laser radiation leads to obliteration of the cystic cavity, the formation of scar tissue, the elimination of specific symptoms and the decrease in the risk of recurrence of pilonidal disease, which is confirmed by spectroscopy, thermometry and histological studies.

INTENSITY OF FREE RADICAL PROCESSES IN THE POSTNUCLEAR FRACTION OF RAT KIDNEYS UNDER INFLUENCE OF LASER IRRADIATION AND ω-3 POLYUNSATURATED FATTY ACIDS

Introduction. The effect of laser irradiation on the body can lead to local tissue damage, which will be accompanied by changes in biochemical processes that occur in the kidneys. The direction of these changes is completely unclear, so the study of free radical oxidation of lipids and proteins as the main markers of oxidative stress in the body and their correction by ω-3 polyunsaturated fatty acids (PUFA) remains relevant. Aim. To evaluate the intensity of lipid peroxidation and oxidative modification of proteins in the postnuclear fraction of rat kidneys under the action of laser irradiation and additional administration of ω-3 PUFA. Methods. The studies used white outbred rats, which were irradiated daily for 4 minutes with a laser diode with a wavelength of 650 nm, power of 50 mW in the abdominal cavity at a distance of 10 cm from the skin surface. The state of lipid peroxidation (LPO) was determined by the level of primary, secondary and final products. The intensity of oxidative modification of proteins (OMP) was evaluated by the level of carbonyl derivatives and protein SH-groups. To correct the prooxidant state, the animals were additionally injected with ω-3 PUFA. Results. Low-intensity laser irradiation has a destructive effect on the cell membranes of the kidneys, which is expressed by an increase in primary, secondary and final products of LPO in phospholipid extracts and an increase in the intensity of OMP. The introduction of ω-3 PUFAs reduces free radical processes in the kidneys of irradiated rats, but this effect depends on the scheme of their introduction. ω-3 PUFAs do not show antioxidant effect under the conditions of their introduction after laser irradiation. Daily administration of ω-3 PUFA two hours before irradiation shows a slight antioxidant effect only in the initial stages of irradiation. Preliminary seven-day administration of ω-3 PUFA before laser irradiation is the most effective, as it helps to reduce free radical processes. Conclusion. It is established that ω-3 PUFAs are able to have a corrective effect on the action of low-intensity laser irradiation, which depends on the scheme of their introduction. The highest antioxidant effect is observed in groups of animals to which ω-3 PUFA was previously administered before the action of laser irradiation.

Effect of UV Laser Radiation on "Positive Regulation of Telomere Maintenance" in Saccharomyces cerevisiae.

Introduction: Excessive exposure to ultraviolet (UV) radiation may cause a variety of skin cancers and damage to the eye lens. The assessment of different aspects of UV damage has attracted researchers' interest. UV radiation to simple biological models such as Saccharomyces cerevisiae of yeast family could help to find out different molecular changes resulting from radiation. The assessment and network analysis of gene expression data about yeast cells radiated by the UV laser was the aim of this study. Methods: The gene expression profiles of S. cerevisiae samples in the presence of the UV laser at 30 seconds radiation and 15 minutes' post-radiation time are compared with the control profiles. The significant expressed genes interacted and the central nodes and related biological terms were identified. Results: The main connected component of the network including 427 nodes was analyzed and 11 central differentially expressed genes (DEGs) were determined. RPN11, UBI4, HSP82, and HSC82 as critical DEGs and "positive regulation of telomere maintenance" as a related biological term were introduced. Conclusion: The finding has provided a new perspective on laser application in the rejuvenation process. It seems that the laser can be used as a suitable agent against the aging process which is a limiting factor in human life.

Photobiomodulation of inflamed dental pulp stem cells under different nutritional conditions.

Aim: The present study aimed to investigate photobiomodulation's (PBM) effect on inflamed dental pulp stem cells (IDPSCs) under different nutritional conditions. Methods: Cell proliferation and odontogenic differentiation were evaluated using the MTT assay and real-time quantitative reverse transcription PCR, respectively after laser PBM of cells in 5 or 10% fetal bovine serum (FBS) culture conditions. Results: A significant positive effect of laser irradiation on cell proliferation under both nutritional conditions after 24 and 48h was observed. DMP-1 gene expression increased in the groups with laser irradiation and 5% FBS. Comparison of gene expression levels in the four groups revealed no statistically significant stimulatory effect. The highest gene expression was observed in the non-laser group with 5% FBS. Conclusion: Further studies are required to obtain an irradiation setup to ideally improve inflamed dental pulp stem cells' proliferation and differentiation.

CHARACTERISTICS OF THE INTERACTION BETWEEN LOW-INTENSITY LASER RADIATION AND ERYTHROCYTES

The results of the effect of low-intensity laser radiation on lipid peroxidation and the sorption capacity of erythrocyte membranes under stress are presented. The membrane-stabilizing effect of low-intensity laser radiation and a decrease in the rate of free radical processes are noted, which indicates the prospects of using laser radiation as an activator of the body's natural antioxidant systems. An increase in the sorption capacity of erythrocyte membranes proves the advisability of using low-intensity laser radiation to increase the adaptive capacity and to protect the body from stress.