Effects of He-Ne laser irradiation on chronic atrophic gastritis in rats

AIM: To study the effects of He-Ne laser irradiation on experimental chronic atrophic gastritis (CAG) in rats.METHODS: Sixty-three male adult Wistar rats were randomly divided into five groups including normal control group, model control group and three different dosages He-Ne laser groups. The chronic atrophic gastritis (CAG)model in rats was made by pouring medicine which was a kind of mixed liquor including 2% sodium salicylate and 30% alcohol down the throat for 8 wk to stimulate rat gastric mucosa, combining with irregular fasting and compulsive sporting as pathogenic factors; 3.36, 4.80, and 6.24J/cm2doses of He-Ne laser were used, respectively for three different treatment groups, once a day for 20 d. The pH value of diluted gastric acid was determined by acidimeter,the histopathological changes such as the inflammatory degrees in gastric mucosa, the morphology and structure of parietal cells were observed, and the thickness of mucosa was measured by micrometer under optical microscope.RESULTS: In model control group, the secretion of gastric acid was little, pathologic morphological changes in gastric mucosa such as thinner mucous, atrophic glands, notable inflammatory infiltration were found. After 3.36 J/cm2 dose of He-Ne laser treatment for 20 d, the secretion of gastric acid was increased (P＜0.05), the thickness of gastric mucosa was significantly thicker than that in model control group (P＜0.01), the gastric mucosal inflammation cells were decreased (P＜0.05). Morphology, structure and volume of the parietal cells all recuperated or were closed to normal.CONCLUSION: 3.36J/cm2 dose of He-Ne laser has a significant effect on CAG in rats.

Effect of three-volt moxibustion with helium-neon laser irradiation on quality of care in patients with lumbar radiculopathy spondylosis

BACKGROUND Lumbar radiculopathy spondylosis is a relatively common orthopedic disease with a high incidence rate.It most commonly occurs in the lumbar 4-5 and lumbar 5-sacral 1 vertebrae,which account for approximately 95%of cases.It mostly occurs in people aged 30-50 years old and greatly affects their quality of life.AIM To determine the effect of triple-voltage acupuncture combined with helium-neon laser irradiation on the quality of care and improvement of symptoms in patients with lumbar radiculopathy spondylolisthesis.METHODS In this study,we selected 120 patients with lumbar radiculopathy spondylosis who were treated at our hospital between June 2019 to June 2020.The patients were divided into control and observation groups according to the random number table method,with 60 patients in each group.Patients in the observation group were treated with three-volt moxibustion combined with helium-neon laser irradiation,and those in the control group were treated with lumbar traction.After 1 month of treatment,the lumbar pain scores,lumbar spine motor functions,clinical treatment effects,and nursing satisfaction of the two groups were compared.RESULTS The results showed that acupuncture combined with laser irradiation significantly improved the patients'clinical symptoms,i.e.,reduced their low back pain,significantly lower numerical rating scale pain scores in the observation group than in the control group,and better lumbar spine motility than in the control group,compared to lumbar traction.In addition,they were cared for.The treatment effectiveness rate of the observation group was 95.5%,which was significantly higher than that of the control group(81.67%).Satisfaction with care was higher than 90 points in both groups,but the difference was not statistically significant.CONCLUSION Our study provides a clinical rationale for the future treatment of patients with lumbar spine disease.However,further extensive research is needed for validation.

Influence of He-Ne laser irradiation on the excision repair of cyclobutyl pyrimidine dimers in the wheat DNA

Using agarose gel electrophoresis and T4-endo-deoxyribonuclease-V, which is a kind of restriction endonu-clease of cyclobutyl pyrimidine dimer (CPD), the impacts of He-Ne laser (5mW·mm-2) irradiation on DNA excision repair capacity in damaged wheat cells induced by enhanced ultraviolet-B (10.08kJ·m-2·d-1) radiation were studied. The results indicated that the content of endonuclease sensitive sites (ESS) was reduced by He-Ne laser irradiation, which formed in cells irradiated by enhanced ultraviolet-B. With the irradiation of He-Ne laser, the excision of CPDs and the reduction of single strand breaks (SSB) contents which were the endonuclease sensitive sites (ESS) digested by T4-endodeoxyribonuclease-Y had been stimulated in the wheat cells.

Enhancement of Human Blood Storage Period by Irradiation of Low Level He-Ne Laser

The aim of the present work is to investigate the effect of the He-Ne laser irradiation on the whole human blood (HB) in order to enhance the conditions of conservation. The HB was irradiated by He-Ne laser;(λ = 632 nm, continuous wave, power 30 mW, 2 mm diameter beam spot), electrical properties and complete blood count CBC were measured at three doses (0.0287, 0.0563 and 0.198 J/cm3) to the relevant best exposure dose during storage periods 9, 24, 30, 35 & 50 days. The irradiation process with the selected dose was performed by the exposure of the laser beam on the blood sample flow through narrow tube of cross section area, 0.0831 cm2. Blood dielectric parameters, (electric conductivity, dielectric constant, dielectric loss and dipole moment) and CBC, (red blood cell, white blood cell, hematocrit, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, and mean cell or corpuscular hemoglobin in concentration) were measured. The obtained results were compared with that of the control and showed that the best irradiation exposure dose suitable for increasing the time of blood storage with minimum changes in properties is 0.198 J/cm3 and storage period of about 50 days. The present study revealed that irradiation by He-Ne laser could be considered a good means to improve the conservation conditions of human blood.

Effect of 532 nm Laser Irradiation on Vc Content in Cabbage Seedlings

[ Objective ]The aim of this study was to discuss the feasibility of breeding cabbage with high Vc by 532 nm laser.[ Method ] With the material of cabbage, the embryo of cabbage seeds was irradiated by frequency doubled Nd ：YAG laser with different power densities and time, and the effects of laser mode on functional leaf area, chlorophyll and Vc contents in cabbage seedlings were also studied. [Result] The results showed that functional leaf area and chlorophyll content were related to laser power density and time when laser power density was 2 -20 mW/mm^2, while the optimal effect was observed at 14 mW/mm^2 for 1 min. The content of Vc in cabbage seedlings was related to dosage of laser irradiation when irradiating time ranged from 1 to 5 min, and the optimal effect was observed at 2.8 J （20 mW/mm^2, 3 min）. [Conclusion] Irradiating the embryo of cabbage seeds with proper irradiation dosage of 532 nm laser can increase its effect on the Vc content significantly.

Low-power laser irradiation promotes the proliferation and osteogenic differentiation of human periodontal ligament cells via cyclic adenosine monophosphate

Retaining or improving periodontal ligament （PDL） function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation （LPLI） on the proliferation and osteogenic differentiation of human PDL （hPDL） cells. Cultured hPDL cel Is were irradiated （660 nm） daily with doses of O, 1, 2 or 4 J .cm-2. Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide （MTT） assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase （ALP） activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction （RT-PCR）. Our data showed that LPLI at a dose of 2 J.cm-2 significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J.cm-2 showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate （cAMP） is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.

Stimulated photoluminescence emission and trap states in Si/SiO_2 interface formed by irradiation of laser

Stimulated photoluminescence （PL） emission has been observed from an oxide structure of silicon when optically excited by a radiation of 514nm laser. Sharp twin peaks at 694 and 692nm are dominated by stimulated emission, which can be demonstrated by its threshold behaviour and linear transition of emission intensity as a function of pump power. The oxide structure is formed by laser irradiation on silicon and its annealing treatment. A model for explaining the stimulated emission is proposed, in which the trap states of the interface between an oxide of silicon and porous nanocrystal play an important role.

Low-power laser irradiation inhibits arecoline-induced fibrosis:an in vitro study

Oral submucous fibrosis （OSF） is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major aetiological factor in the development of OSF. Low-power laser irradiation （LPLI） has been reported to be beneficial in fibrosis prevention in different damaged organs. The aim of this study was to investigate the potential therapeutic effects of LPLI on arecoline-induced fibrosis. Arecoline- stimulated human gingival fibroblasts （HGFs） were treated with or without LPLI. The expression levels of the fibrotic marker genes alpha-smooth muscle actin （a-SMA） and connective tissue growth factor （CTGF/CCN2） were analysed by quantitative real- time reverse transcription polymerase chain reaction （RT-PCR） and western blots. In addition, the transcriptional activity of CCN2 was further determined by a reporter assay. The results indicated that arecoline increased the messenger RNA and protein expression of CCN2 and a-SMA in HGF. Interestingly, both LPLI and forskolin, an adenylyl cyclase activator, reduced the expression of arecoline-mediated fibrotic marker genes and inhibited the transcriptional activity of CCN2. Moreover, pretreatment with SQ22536, an adenylyl cyclase inhibitor, blocked LPLI＇s inhibition of the expression of arecoline-mediated fibrotic marker genes. Our data suggest that LPLI may inhibit the expression of arecoline-mediated fibrotic marker genes via the cAMP signalling pathway.

Irradiation effects of CO_2 laser parameters on surface morphology of fused silica

To understand the surface morphology evolution of fused silica induced by 10.6μm CO2 laser irradiation at different parameters, this paper reports that optical microscopy, profilometry, and hydrophilicity tests are utilized to characterize the surface structure and roughness of the laser irradiated area. The results show that three typical surface morphologies and two typical hydrophilicity test images are observed at different laser powers and pulse durations. The correlations between surface temperature and surface morphology as well as hydrophilicity behaviours are presented. The different hydrophilicity behaviours are related to surface structures of the laser-induced crater and thermal diffusion area. The thermal diffusion length monotonously increases with increasing laser power and pulse duration. The crater width is almost determined by the laser beam size. The crater depth is more sensitive to the laser power and pulse duration than the crater width.

The Effect of Laser Irradiation on Surface Enhanced Raman Scattering for Silver Film

The laser irradiation effect on the SERS intensity for Ag film is discussed using crystal violet (CV) as a probe. The thickness of silver film,the etching time of the glass slide by gaseous hydrogen fluoride, and the laser irradiation time for different amounts of CV on silver films were investigated. The laser burn out model was proposed to explain the dependence of the SERS intensity of CV on the laser irradiation time.

The influence of He-Ne laser on scar formation after trabeculectomy in rabbits

AIMTo investigate the influence of He-Ne lasers on scar formation in the filtration canal after trabeculectomy in a rabbit model, as well as to explore the mechanisms for preventing scar formation when using He-Ne lasers in vivo.

The Effects of He-Ne Laser and Enhanced Ultraviolet-B Radiation on Proliferating-Cell Nuclear Antigen in Wheat Seedlings

The level of ultraviolet-B (UV-B) radiation on the Earth’s surface has increased due to depletion of the ozone layer. Here, we explored the effects of continuous wave He-Ne laser irradiation (632 nm, 5 mW·mm-2, 2 min·d-1) on proliferating-cell nuclear antigen (PCNA) damage repair function of wheat seedlings exposed to enhanced UV-B radiation (10.08 kJ&middotm-2·d-1) at the early growth stages. Wheat seedlings were irradiated with enhanced UV-B, He-Ne laser treatment or a combination of the two. We explored the transcripts of PCNA in each treatment group using RT-PCR. In addition, total proteins were extracted from the 7-day-old wheat leaves, analyzed by SDS-PAGE and identified by western blot. The results showed that the transcription of PCNA was weakened following UV-B radiation compared to the control. However, when seedlings were subjected to elevated UV-B-damaging radiation followed by He-Ne laser irradiation, the expression of PCNA was signifi-cantly higher than UV-B radiation alone. These results suggest that He-Ne laser has an active role in repairing the UV-B damaging effects. In order to further investigate the function of PCNA, dynamic arrangements of PCNA in wheat root-tip cells were observed with confocal laser scanning microscopy (CLSM). The PCNA was marked fluorescent dimming and strength weakened in en-hanced UV-B radiation (UV-B) compared with the control group (CK) during processing. It shows that PCNA may be involved in the separation of chromosomes.

Study on the Antitumor Effects of Low-energy Laser Irradiation Combined with Cyclophosphamide

Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascites sarcoma.The three groups of tumor bearing mice were irradiated upon the inner corners with the dosages of 11 00,14 67 and 22 00 J·cm -2 LELI respectively,and injected with CYT intraperitoneally to observe the changes of the survival time,the ascites growth speed,and the kinetic changes of immune functions.The survival times of the three groups of CYT/LELI combination were obviously longer than those of the tumor and CYT control groups.Correspondingly,the amounts of ascites,tumor cells densities and total tumor cells in CYT/LELI groups decreased significantly,while the death ratio of the tumor cells increased.Comparatively,the group of 22 00 J·cm -2 LELI combined with CYT showed the most ideal antitumor effects,and the life prolongation ratio was up to 53 20%.

Formation and Growth of Silver Nanocubes upon Nanosecond Pulsed Laser Irradiation: Effects of Laser Intensity and Irradiation Time

Silver nanoparticles (AgNPs) were fabricated by repetitive irradiation of near ultraviolet (UV) nanosecond laser pulses (355 nm, 5 ns) in an aqueous solution of silver nitrate in the absence of stabilizing agents. A broad absorption peak was observed in the visible region showing the formation of a variety of AgNPs in the solution. Among the variety of products, it was found that silver nanocubes (AgNCs) grew in size with longer laser irradiation time. The size of AgNCs also increased with higher laser intensity. The average size of AgNCs, investigated by a scanning electron microscope (SEM) was in the range of 75 - 200 nm. The number of reduced atoms in AgNCs as a function of laser intensity showed that the AgNCs are apparently produced by a four photon process, implying that the formation of dimer silver atoms is essential for the formation.

Electrokinetic-mechanism of water and furfural oxidation on pulsed laser-interlaced Cu_(2)O and CoO on nickel foam

The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.

Fabrication of Through Micro-hole Arrays in Silicon Using Femtosecond Laser Irradiation and Selective Chemical Etching

We demonstrate a method of fabricating through micro-holes and micro-hole arrays in silicon using femtosecond laser irradiation and selective chemical etching. The micro-hole formation mechanism is identified as the chemical reaction of the femtosecond laser-induced structure change zone and hydrofluoric acid solution. The morphologies of the through micro-holes and micro-hole arrays are characterized by using scanning electronic microscopy, The effects of the pulse number on the depth and diameter of the holes are investigated. Honeycomb arrays of through micro-holes fabricated at different laser powers and pulse numbers are demonstrated.

Protecting effect of He-Ne laser on winter wheat from UV-B radiation damage by analyzing proteomic changes in leaves

The ultraviolet-B (UV-B) radiation can affect gene expression of plant in growth and development. Winter wheat (Triticum aestivum), as a kind of economic crop cultured in the Northern China, is also damaged by present-day ultraviolet-B (UV-B) radiation. It was reported that He-Ne lasers could alleviate cell damage caused by UV-B radiation in plants. To get the proteomic changes of wheat alleviated by He-Ne lasers, we studied protein expression profiles of winter wheat (Jin Mai NO.79) leaves by running 2-DE (two-dimensional gel electrophoresis), which allowed the identification of some significantly different gel spots. The spots were further verified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, in which they were confirmed to be winter wheat proteins. The results showed: 1) the proteomic changes between the ultraviolet-B radiation group and normal light group were significantly different on sixth day;2) The expression of some proteins such as catalase, DNA polymerase and reduced glutathione declines at the ultraviolet-B radiation group and increases at the UV-B + He-Ne laser group. This indicates UV-B could regulate genes encoding proteins in Winter wheat leaves and affect the growth of the Winter wheat. He-Ne lasers treatment could significantly alleviate UV-B-induced damage in wheat.

Reduction of Radiation Damage in Mice after Acute and Prolonged Irradiation with Gamma Rays by Means of Laser Device

An opportunity to use laser radiation as a means to reduce negative aftermath of acute and prolonged exposure to ionizing radiation was checked. The mice were exposed to γ- rays of ^60Co （whole body irradiation） in the dose of 7 Gy （the transitional clinical form of the acute radiation sickness）. The dose rate at acute irradiation was 1.14 Gy/min, and at prolonged exposure, 0.027 Gy/min. Laser radiation in the dose l mJ/cm^2 was used to irradiate only the back of a mouse. First, the mice were exposed to γ-radiation, then to laser radiation. The time interval between two types of irradiation did not exceed 30 min. It was shown that the radiation protection of mice with laser radiation is possible at exposure to ionizing radiation in a wide dose interval and can reduce negative after-effects of both the acute and prolonged radiation exposure.

Ultrafast Laser-Induced Excellent Thermoelectric Performance of PEDOT:PSS Films

Because poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)is water processable,thermally stable,and highly conductive,PEDOT:PSS and its composites have been considered to be one of the most promising flexible thermoelectric materials.However,the PEDOT:PSS film prepared from its commercial aqueous dispersion usually has very low conductivity,thus cannot be directly utilized for TE applications.Here,a simple environmental friendly strategy via femtosecond laser irradiation without any chemical dopants and treatments was demonstrated.Under optimal conditions,the electrical conductivity of the treated film is increased to 803.1 S cm^(-1)from 1.2 S cm^(-1)around three order of magnitude higher,and the power factor is improved to 19.0μW m^(-1)K^(-2),which is enhanced more than 200 times.The mechanism for such remarkable enhancement was attributed to the transition of the PEDOT chains from a coil to a linear or expanded coil conformation,reduction of the interplanar stacking distance,and the removal of insulating PSS with increasing the oxidation level of PEDOT,facilitating the charge transportation.This work presents an effective route for fabricating high-performance flexible conductive polymer films and wearable thermoelectric devices.

A quantitative method for calculating irradiation area of laser target designator

In laser-guided bomb attacking process,the target indication from the laser target designator is the premise for the bomb to hit the target accurately.Considering the lack of quantitative study of the irradiation area of the laser target designator,this paper,based on the existing aircraft motion model and the laser transmission model,uses two aircraft as respectively the carrier of the laser-guided bomb and the carrier of the laser designator and proposes a method to calculate the global irradiation area of the airborne laser designator.By using the proposed algorithm,the global irradiation area when attacking a large flat target or a large spherical target is simulated respectively.Finally,according to the simulation results,the influences of different factors on the shapes of the irradiation area are discussed in detail.