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Nd:YAG laser vs IPL in inflammatory and noninflammatory acne lesion treatment
摘要： Background: Several topical and systemic therapies are available for the treatment of acne vulgaris but are associated with several limitations, and recently, intense pulse light (IPL) and long-pulsed 1064 nm Nd: YAG laser have shown efficacy. Aims: The current study aimed to compare the efficacy of Nd:YAG laser and IPL in inflammatory and noninflammatory acne lesions. Patients and Methods: Thirty patients with inflammatory and noninflammatory facial acne were assigned randomly and equally into two groups, the Nd:YAG and IPL groups. The patients received three sessions of laser 2 weeks apart, and the clinical improvement was assessed by the reduction in the number of lesions. Results: At baseline, the two groups showed a nonsignificant difference as regards total number (P = .476), inflammatory (P = .457), and noninflammatory lesions (P = .420). The improvement in total lesions was significant in the Nd:YAG Group but nonsignificant in the IPL Group (P < .001, P = .13, respectively). Three patients (20%) in the IPL Group showed exacerbation after the first and second sessions. One month after the last session, the difference in improvement between noninflammatory and inflammatory lesions showed a significant difference in the Nd:YAG Group (P = .017) and a nonsignificant difference in the IPL Group (P = .823). Nd:YAG, compared to the IPL Group, showed a significant difference as regards the improvement score in noninflammatory lesions (P = .0099) and a nonsignificant difference in inflammatory lesions (P = .4295). Conclusion: The significant improvement in noninflammatory lesions and the absence of a significant flare-up of acne as seen among patients treated with IPL make Nd:YAG a better therapeutic modality for acne.
关键词： IPL,Nd:YAG,noninflammatory acne,inflammatory acne
更新于2025-09-16 10:30:52
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Laser-Aided Enamel Conditioning: A Comparison of Microleakage Under Brackets Following Different Aging Procedures
摘要： Objective: To evaluate microleakage under the orthodontic adhesives applied following two version of erbium:yttrium aluminum garnet (Er:YAG) laser-aided enamel conditioning after thermal and thermomechanical simulators. Materials and Methods: A comparative analytical study based on metal braces bonded on the enamel of extracted teeth (n = 160) etched with acid, Er:YAG laser and Er:YAG laser with an X-Runner handpiece, and self-etch adhesives. An arch wire was ligatured to samples which were embedded in acrylic blocks by two with periodontal ligaments. The specimens were subdivided into two groups: those aged with thermal cycling and thermomechanical aging procedures. The samples were immersed in basic fuchsin solution (0.5%) for 24 h. Buccolingual sections were performed on the mesial and distal wings of the braces. The color penetration at the gingival and occlusal margins of the adhesive-bracket and enamel-adhesive was evaluated under a stereomicroscope. The median and mean values of microleakage in both groups were evaluated with Kruskal–Wallis and Mann–Whitney U tests (P < .05). Results: The highest microleakage was recorded in the gingival part of the samples aged with the thermomechanical aging procedure (P = .001). The amount of microleakage generally increased in the samples subjected to thermomechanical loading, but the only significant difference was recorded in the gingival part in each four different conditioning methods. Conclusion: Microleakage of the phosphoric acid-etched groups was recorded with lower values for both aging methods. Thermomechanical aging should be included to microleakage studies due to increased microleakage on gingival side for all etching groups.
关键词： thermomechanical aging,Chewing simulation in orthodontics,microleakage,X-Runner handpiece,Er:YAG Laser
更新于2025-09-16 10:30:52
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Comparaison in vitro des taux d’ablation lithiasiques du laser Thulium fibré et du laser Holmium:YAG pour la lithotritie endocorporelle?: impact de l’utilisation de fibre laser de diamètre 150 μm
摘要： Le laser Thulium fibré (TFL) appara?t comme une alternative au laser Holmium:YAG (Ho:YAG) pour la lithotritie endocorporelle, permettant d’utiliser des fibres de diamètres inférieurs à 200 μm. L’objectif était de comparer in vitro les diamètres des fragments, des fissures, et des volumes d’ablation lithiasiques selon le diamètre de fibre laser (CDF) (272 μm ou 150 μm) avec le TFL et le Ho:YAG.
关键词： ablation lithiasique,laser Thulium fibré,laser Holmium:YAG,lithotritie endocorporelle
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Wide-spectrum properties of Yb: YAG crystal-derived fiber
摘要： We designed and fabricated an Yb: YAG crystal-derived fiber (YDF) by CO2-laser drawing tower. The fluorescence spectra and amplifier characteristics were discussed in detail.
关键词： optical properties,Yb: YAG crystal-derived fiber,fiber amplifier
更新于2025-09-16 10:30:52
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Detection of heavy metal containment of soil pollution due to waste of paper industry using Nd:YAG laser induced breakdown spectroscopy
摘要： Detection of heavy metal containment of soil pollution has been made by using laser-induced breakdown spectroscopy (LIBS). A pulsed Nd:YAG laser (1064 nm, 8 ns, 200 mJ) was focused on to a soil sample, which is prepared in the form of pellet, at atmospheric pressure. Emission spectra taken from the waste-contaminated soil and uncontaminated soil were obtained. Plasma emissions are then detected using a multichannel analyzer (OMA) to obtain the emission line spectrum that represents the content of atoms and molecules in the target material. The spectrum is recorded and compared with the spectrum of reference standards of atoms, ions and molecules (National Institute of Standards and Technology/NIST) so that the atomic and molecular content in the sample can be known. From the results of the study it was found that there are elements of heavy metals in the form of Fe, Cd, and Mg in polluted soils.
关键词： LIBS,laser-induced breakdown spectroscopy,soil pollution,heavy metal,Nd:YAG laser
更新于2025-09-16 10:30:52
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An Integrated Approach for optimization of Pulsed ND: YAG Laser Beam Welding process
摘要： Laser beam welding is a non-traditional, advanced technique used for similar & dissimilar materials and is widely used in various industries like automobile, aerospace, nuclear reactors, etc. at a faster pace. As it is a complex process, it is very difficult to find the optimal process parameters. The primary point of welding is to acquire a high quality joints and requiring little to no effort. However, without optimization, it is impractical to accomplish minimal effort welding. The principle work of this exploration is to display, break down and improve weld bead geometry in the powerful ND: YAG laser butt welding of Inconel 625. However, in view of the literature review, the responses are continuous and have impact on the welding geometry. In this way the feasible varieties of the judgment factors are started by coordinating trial tests. The Design of Experiment (DOE) system is used to generating the experimental plan and then conducting the experiments according to the plan. After recording the responses Reaction Surface Methodology (RSM) is received for precise expectation numerical models to evaluate the response variables and are created from the experimental information. Artificial Neural Networks (ANNs) have adopted from the MATLAB software for analysing the output response regression and provide the best curve fitting among the input and output variables.
关键词： DOE,ANN,Inconel 625,ND:YAG Laser,RSM
更新于2025-09-16 10:30:52
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Full-Field Erbium:YAG Laser Resurfacing: Complications and Suggested Safety Parameters
摘要： Background: Laser skin resurfacing with erbium-doped yttrium aluminum garnet (Er:YAG) lasers is a newer alternative to CO2 laser treatment, and was developed to reduce common complications. Although Er:YAG lasers have been available for years, safety parameters for efficacious resurfacing with these devices have not previously been available. Objectives: The aim of this study was to utilize one practice’s laser treatment settings and outcomes data to identify complication rates for various energies and areas of the face and to offer safe energy/depth parameters for treating each area. Methods: A retrospective chart review was performed for full-field confluent laser resurfacing patients treated with a Sciton Contour Tunable Resurfacing Er:YAG laser by the senior author. The data were retroactively analyzed with a time range of 8?years (January 2007-December 2015). Results: The overall complication rate for MicroLaserPeels (ablation of 50?μm or less) was 10.1% (20 of 198 treatments) and the rate for deep resurfacing treatments was 26.5% (71 of 268 cases). In MicroLaserPeel treatments the cheek area had the highest complication rate, followed by the forehead, nose, perioral, and eyelid areas, in that order (complication rate range, 0%-9.1%). In deep resurfacing treatments the perioral area had the highest complication rate, 38.6% of 145 cases. This was followed by the lids, cheek, nose, and forehead, in that order (complication rate range, 15.2%-20.9%). There is a correlation between increased depth of ablation and increased rate of complication. Conclusions: The study confirmed the efficacy of Er:YAG resurfacing and provides guidance for a safer approach to excellent outcomes.
关键词： complications,laser skin resurfacing,safety parameters,Er:YAG laser
更新于2025-09-16 10:30:52
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Optimization of Process Parameters and Comparative Study on Bi-Metallic Joints Developed by High Temperature Nicrobrazing, Laser and GTAW Joining Processes
摘要： High Temperature Nicrobrazing of AISI 316 and 316 L stainless steels has been studied by comparing with pulsed laser and gas tungsten arc welding processes. Fabrication of instrumented irradiation capsule for evaluating the irradiation performance of fuel and structural materials in a nuclear reactor requires development of thin wall joints capable of withstanding high temperature and/or internal pressure. Thin wall joints for high temperature (~550 °C) applications can be made by Laser Beam Welding (LBW), Gas Tungsten Arc Welding (GTAW) and High Temperature Brazing (HTB) methods. Using these methods, joints have been prepared and tests such as helium leak test (HLT) and microhardness test have been carried out. Microstructures were also evaluated. A comparative study has been performed on these joining methods to identify the suitable methods for high temperature applications. No observable leak was found during HLT. Microstructures of joints shows variation in solidification morphology due to difference in heat sources. It has been observed that the joint prepared by high temperature brazing process is having higher microhardness value than the joints prepared by LBW and GTAW processes. Further, it has been observed that LBW joints have better mechanical properties than GTAW joints and HBW joints.
关键词： AISI 316,GTAW,HTB,Tube to End plug,Nd:YAG Laser welding,AISI 316L
更新于2025-09-16 10:30:52
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Kinetics of Cr <sup>3+</sup> to Cr <sup>4+</sup> ion valence transformations and intra-lattice cation exchange of Cr <sup>4+</sup> in Cr,Ca:YAG ceramics used as laser gain and passive Q-switching media
摘要： This paper focuses on the kinetics of Cr4+ formation in Cr,Ca:YAG ceramics prepared by solid-state reaction sintering. The kinetics of Cr4+ formation was studied by annealing of Cr,Ca:YAG ceramics in ambient air under different temperatures at different times, resulting in the transformation of Cr3+ to Cr4+. The activation energy (Ea) of Cr3+ oxidation determined by the Jander model was 2.7 ± 0.2 eV, which is in good correlation with the activation energy of innergrain oxygen diffusion in the YAG lattice. It is concluded that Cr3+ to Cr4+ transformation in YAG ceramics is limited by oxygen diffusion through the grain body. It was established that in Cr,Ca:YAG ceramics, the intralattice cation exchange, in which the Cr4+ ions exchange positions with the Al3+ ions, switching from “A” to “D” sites, is faster than Cr3+ to Cr4+ oxidation. In the temperature range of 900–1300 ○C, the reaction enthalpy of Al3+/Cr4+ ion exchange between octahedral “A” and tetrahedral “D” lattice sites is close to zero, and this exchange ratio is thermodynamically driven by entropy.
关键词： intralattice cation exchange,Cr4+:YAG ceramics,solid-state reaction sintering,oxygen diffusion,Cr3+ oxidation
更新于2025-09-16 10:30:52
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Immediate effect of pulsed high-intensity neodymium-doped yttrium aluminum garnet (Nd: YAG) laser on staphylococcus aureus and pseudomonas aeruginosa growth: an experimental study
摘要： The aim of this study was to evaluate the effect of pulsed high intensity neodymium-doped yttrium aluminum garnet (Nd: YAG) laser on staphylococcus aureus (S. aureus) and pseudomonas aeruginosa (P. aeruginosa) bacterial growth, which cause many health problems and establish which doses are effective in bacterial inhibition. Five samples of S. aureus and five samples of P. aeruginosa were prepared in the microbiology lab, one used as control sample and the other 4 samples acted as experimental samples. The experimental samples received pulsed high intensity Nd: YAG laser with a total dose of 500, 600, 700 and 800 joules. The primary measures are colony count and the percentage decrease in colony count, the colony count was assessed at baseline and after 24 h of laser application. There was significant decrease in colony count and the percentage decrease in colony count after pulsed high intensity Nd: YAG laser application in all experimental samples of S. aureus and P. aeruginosa after 24 h of application for all doses (500, 600, 700 and 800 j) as compared with the control sample, with the most effect in higher doses of pulsed high intensity Nd: YAG laser than lower doses in both types of bacteria. pulsed high intensity Nd: YAG laser was found to be an effective modality for inhibition of S. aureus and P. aeruginosa growth after a single application.
关键词： Bacterial growth,Pulsed high intensity neodymium-doped yttrium aluminum garnet (Nd: YAG) laser,Colony count
更新于2025-09-16 10:30:52