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Fabrication and AFM characterization of selenium recycled nano particles by pulse laser evaporation and thermal evaporation
摘要： The feasibility of waste collection strikethrough in the traditional evaporation deposition system after preparing thin films was investigated. In this paper, first, the Selenium thin films of 0.5 μm thickness were prepared by a thermal vacuum evaporation system and an evaporation assisted laser Neodymium - Yag pulsed Nd:YAG laser system. Then, the waste materials that remain in the systems were collected and examined. The inspections include the particle size and other structural properties, taken before and after annealing at 300 °C for 30 min. Results show that the prepared thin film and particles are crystalline and the particle size of collected particles are in the range of about <50 nm, which makes this method very useful in the production of recycled nanoparticles of metals and materials that are costly or harmful, but can be an advantage and beneficial.
关键词： recycled nanoparticles,selenium,Nd: YAG laser,thin film,annealing
更新于2025-09-19 17:13:59
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Adjunctive effects of laser therapy on somatosensory function and vasomotor regulation of periodontal tissues in patients with periodontitisa?? A randomized controlled clinical trial
摘要： Background: The purpose of this prospective study was to compare the changes in periodontal somatosensory function and microcirculation in patients with periodontitis following initial treatment with scaling and root planing (SRP) with or without adjuvant laser therapy. Methods: Twenty-four patients suffering from periodontitis were recruited and randomly allocated into a split-mouth design to either SRP combined laser therapy side (test side) or SRP only side (control side). All treatments were performed by the same investigator at a single visit. Laser Doppler Flowmetry (LDF) and Quantitative Sensory Testing (QST) were performed at baseline (W0), 1 week (1W), 2 weeks (2W), and 4 weeks (4W) after treatment on both sides of the attached gingiva of the maxillary lateral incisor. Clinical examination including pocket probing depth (PPD) and bleeding on probing (BOP) was performed at W0, 2W, and 4W on both sides. Data were analyzed with two-way analysis of variance (ANOVA). Results: The PPD and BOP significantly improved after treatment (P <0.001). The LDF values were significantly decreased on both sides at all follow-up time points (P <0.001), temperature was increased only on the test side (P =0.017) whereas there was no significant change on the control side (P=0.792). Significantly less sensitivity was observed for all QST parameters (P <0.030) except for warmth detection after treatment. Conclusion: Adjunctive use of laser therapy did not provide any significant clinically advantage or additional effects on the recovery of periodontal somatosensory function or gingival microcirculation in the present study.
关键词： Quantitative sensory testing,periodontal somatosensory function,inflammation,Nd:YAG laser,blood flow
更新于2025-09-19 17:13:59
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The Effect of Capsulotomy Shape on Intraocular Light-Scattering after Nd:YAG Laser Capsulotomy
摘要： Purpose. To investigate the effects of capsulotomy shape on the visual acuity and visual quality after neodymium: yttrium aluminum garnet laser capsulotomy. Methods. In this study, a total of 42 eyes from 35 patients with posterior capsule opacification were divided into the circular and cruciate groups. The corrected distance visual acuity (CDVA), objective scatter index (OSI), modulation transfer function cutoff (MTF cutoff), Strehl ratio, and Optical Quality Analysis System values at contrasts of 100%, 20%, and 9% (OV-100, OV-20, and OV-9) were measured at precapsulotomy and 1 week and 1 month postcapsulotomy. The pseudophakic dysphotopsia questionnaire (PDQ) was used to evaluate the subjects’ satisfaction with treatment. Results. OSI values were significantly higher in the cruciate group than in the circular group at 1 week and 1 month after capsulotomy (P = 0.013 and P < 0.001). No significant difference was found in the OSI values between the two groups before capsulotomy (t = 0.52; P = 0.61). The decrease in OSI was higher in the circular group than in the cruciate group at 1 week and 1 month after capsulotomy (P = 0.036 and P = 0.019). No significant differences were found in the Strehl ratio, MTF cutoff, CDVA, OV-100, OV-20, and OV-9 between the two groups at 1 week and 1 month after capsulotomy (P > 0.05). The PDQ results showed that patients with circular-shaped capsulotomy complained less with intolerance of bright lights than those with cruciate-shaped capsulotomy. Conclusions. Circular-shaped capsulotomy can induce less intraocular light scattering and increase patient satisfaction.
关键词： visual acuity,Nd:YAG laser capsulotomy,visual quality,intraocular light-scattering,capsulotomy shape
更新于2025-09-19 17:13:59
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Different Numbers of Long-Pulse 1064-nm Nd-YAG Laser Treatments for Onychomycosis: A Pilot Study
摘要： Purpose. To examine the benefits of different numbers of 1064-nm Nd-YAG laser treatments in patients with onychomycosis. Methods. This was a pilot study of patients with onychomycosis who were divided into three groups: four treatment sessions (group A), eight sessions (group B), and 12 sessions (group C). Only infected nails of degrees II–III (Scoring Clinical Index for Onychomycosis) were included. Treatment was given once a week using a long-pulse Nd-YAG 1064-nm laser. Patients were followed at 8, 16, and 24 weeks after the first treatment. Side effects were recorded. Results. Treatments were completed for 442 nails in 102 patients. The efficacy rates at 8, 16, and 24 weeks were 35.5%, 38.7%, and 37.4% for group A; 31.4%, 41.7%, and 44.0% for group B; and 27.7%, 50.0%, and 55.4% for group C, respectively. There was a significant difference in the efficacy rate at 24 weeks (?? = 0.016) between groups A and C, but not for groups A vs. B, or for groups B vs. C. No difference in the efficacy rate at 8 or 16 weeks was observed among the three groups. In all three groups, the efficacy was better for degree II nails than for degree III nails (all ?? < 0.05). No side effects occurred. Conclusions. The 1064-nm Nd-YAG laser had clinical benefits against onychomycosis. Higher numbers of treatments provided better long-term (24-week) benefits, but had no impact on the short-term outcomes. The efficacy of laser treatment on degree II onychomycosis was better than for degree III.
关键词： side effects,1064-nm Nd-YAG laser,treatment sessions,efficacy,onychomycosis
更新于2025-09-19 17:13:59
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Laser Welding of Transmitting High-Performance Engineering Thermoplastics
摘要： Laser processing is a rapidly growing key technology driven by several advantages such as cost and performance. Laser welding presents numerous advantages in comparison with other welding technologies, providing high reliability and cost-effective solutions. Significant interest in this technology, combined with the increasing demand for high-strength lightweight structures has led to an increasing interest in joining high-performance engineering thermoplastics by employing laser technologies. Laser transmission welding is the base method usually employed to successfully join two polymers, a transmitting one through which the laser penetrates, and another one responsible for absorbing the laser radiation, resulting in heat and melting of the two components. In this work, the weldability of solely transmitting high-performance engineering thermoplastic is analyzed. ERTALON 6 SA, in its white version, is welded by a pulsed Nd:YAG laser. Tensile tests were performed in order to evaluate the quality of each joint by assessing its strength. A numerical model of the joint is also developed to support the theoretical approaches employed to justify the experimental observations.
关键词： pulsed Nd:YAG laser welding,numerical model,polyamide 6,ERTALON 6 SA,high-performance engineering thermoplastic,mechanical testing
更新于2025-09-19 17:13:59
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Endoscopic Diagnosis and Treatment in Prostate Pathology || Laser Treatment for Benign Prostatic Hyperplasia
摘要： The word “LASER” is an acronym for “light amplification by stimulated emission of radiation.” Laser is one of the most important scientific discoveries of the last half of the twentieth century, often compared in importance with the discovery of electricity. Shortly after it was discovered, its applications in industry and especially in medicine increased continuously, contributing to many modern methods of diagnosis and treatment. The progress recorded over the last few years (the emergence of new types of lasers and optical fibers) has transformed laser into one of the ideal sources of energy used in medicine. The development of endoscopic instruments and the possibility of using laser fibers with very small diameters have significantly and positively influenced its use in urology, more than in any other medical specialty.
关键词： Er:YAG,Laser,Diode,Nd:YAG,Urology,Benign Prostatic Hyperplasia,Thulium,Ho:YAG,KTP
更新于2025-09-16 10:30:52
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Study on Features of 532nm Laser as Laser Source of Lidar
摘要： The laser source of Lidar usually uses the high power solid laser, the performance of Lidar depends on the laser features, so that to study the laser features is contribute to optimizing the performance of Lidar. Set up and design a pulse solid laser of Nd3+:YAG as the working substance. Through adopting the KTP crystal frequency multiplication technology outside the laser cavity and electro-optic q-switch technique, the maximum dynamic pulse energy of 155mJ and pulse width of 9.6 ns with the 532nm laser is generated. Using the oscilloscope, photoelectric pulse sensor and laser energy meter to measurement the experimental data of the laser source features Through analyze and discuss the experimental data, the relationship between the pulse width, the static and dynamic ratio, the peak power of the pulse Nd3+:YAG laser, the frequency doubling efficiency of the KTP crystal and the input power of laser are given, the solid laser system and the experimental data can provide a basic equipment and reference data to the further study.
关键词： 532nm laser,High power,Laser tracking system,Nd3+:YAG laser
更新于2025-09-16 10:30:52
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Enhanced topical cutaneous delivery of indocyanine green after various pretreatment regimens: comparison of fractional CO2 laser, fractional Er:YAG laser, microneedling, and radiofrequency
摘要： Different devices have been used to enhance topical drug delivery. Aim of this study was to compare the efficacy of different skin pretreatment regimens in topical drug delivery. In six ex vivo human abdominal skin samples, test regions were pretreated with fractional CO2 and Er:YAG laser (both 70 and 300 μm ablation depth, density of 5%), microneedling (500 μm needle length), fractional radiofrequency (ablation depth of ± 80–90 μm), and no pretreatment. The fluorescent agent indocyanine green (ICG) was applied. After 3 h, fluorescence intensity was measured at several depths using fluorescence photography. Significantly higher surface fluorescence intensities were found for pretreatment with fractional Er:YAG and CO2 laser and for microneedling vs. no pretreatment (p < 0.05), but not for radiofrequency vs. no pretreatment (p = 0.173). Fluorescence intensity was highest for the Er:YAG laser with 300 μm ablation depth (mean 38.89 arbitrary units; AU), followed by microneedling (33.02 AU) and CO2 laser with 300 μm ablation depth (26.25 AU). Pretreatment with both lasers with 300 μm ablation depth gave higher fluorescence intensity than with 70 μm ablation depth (Er:YAG laser, 21.65; CO2 laser, 18.50 AU). Mean fluorescence intensity for radiofrequency was 15.27 AU. Results were comparable at 200 and 400 μm depth in the skin. Pretreatment of the skin with fractional CO2 laser, fractional Er:YAG laser, and microneedling is effective for topical ICG delivery, while fractional radiofrequency is not. Deeper laser ablation results in improved ICG delivery. These findings may be relevant for the delivery of other drugs with comparable molecular properties.
关键词： Radiofrequency,Fractional laser,Er:YAG laser,Microneedling,Drug delivery,CO2 laser
更新于2025-09-16 10:30:52
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Fundamentals of three-dimensional Yb-fiber Nd:YAG laser machining of structural bone
摘要： This work aims to understand the fundamental aspects of the laser-bone interaction in three-dimensional laser machining of the bone through an integrated experimental-computational approach. The study introduces 3-dimensional laser machining of bones through multi-laser passes and attempts to establish the dimensional control over the laser-machined cavity through a finite element method based multi-physics computational model. A continuous wave Yb-fiber Nd:YAG laser (λ = 1064 nm) was employed with laser fluences ranging from 5:31 J/mm2 to 25:46 J/mm2 generated in combination of laser power (400 W–700 W) and machining speed (50 mm/s–250 mm/s). In multi-laser pass machining, the optimum fill spacing of 0.2 mm was identified for higher machining rates with low deviation from linearity of machined edge (d = 9 μm). This resulted in high machining rates ranging from 16:49 + 0:2 mm3/s to 45:26 + 0:66 mm3/s for a given range of laser fluence. The optimization for machining efficiency and physical attributes of the machined cavity were comprehended through thermodynamics and kinetics of the laser interaction with the bone based on the computational model for varying laser processing parameters.
关键词： bone,kinetics,Yb-fiber Nd:YAG laser,laser machining,computational model,three-dimensional,thermodynamics
更新于2025-09-16 10:30:52
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Experimental Investigation of Varying Laser Pass on Micro-channel Characteristics of Thick PMMA by Laser Transmission Micro-machining
摘要： Depth of fabrication is an essential characteristic of micro-channels. The laser beam machining process is one of the most suitable processes to fabricate micro-channels. This process has an excellent potential for the fabrication of microfluidic devices which are instrumental for various biomedical applications such as electrophoresis, chromatography, blood protein studies, DNA analysis, etc. In this research work, an attempt has been made to fabricate micro-channels on a thick Polymethyl methacrylate (PMMA) plate at submerged condition by utilizing laser transmission micro-machining process. The laser transmission micromachining operation is conducted here at submerged condition to reduce the adverse thermal effect during machining. Nanosecond pulsed Nd: YAG laser with wavelength in near infrared region has been used here. The depth of micro-channel and heat affected zone (HAZ) width has been taken into account as machining responses. Total 3 sets of experiments which contain 31 experiments in each set have been conducted for three different laser beam pass with the aid of response surface methodology (RSM). The effects of varying laser beam pass on the depth and HAZ width has been studied.
关键词： Nd: YAG laser,laser transmission machining,micro-channeling,PMMA
更新于2025-09-16 10:30:52