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Study of the Effect Laser Ablation on Structural, Morphological and Optical Characterization of Tin NPs Sn Nanoparticles Thin Films in Methanol
摘要： Tin NPs thin ?lms were successfully prepared on glass substrate at a substrate temperature equal to 80 (cid:3)C of laser ?uence technique. The spray solution prepared from Tin NPs target, immersed in methanol, with Nd:YAG laser pulses at laser ?uences in the range of (2.92) J/cm2. X-ray diffraction show that all the diffract grams contain the characteristic Tin NPs orientations tetragonal structure and the ?lms are polycrystalline with (200) as a preferred growth orientation. The surface morphology of Tin NPs thin ?lm has been investigations by atomic force microscopy (AFM) showed highly dispersed ball-shape Tin NPs particles. We have done other examined of Tin NPs material prepared using laser ?uency which is FTIR measurements, Electrical Conductivity and Scanning electron microscope SEM measurement showed that the shape. The average transmittance in the visible region (at 550 nm) has been found (68%) and the optical energy gap of Tin NPs nanoparticles found to be (1.4 eV).
关键词： NPs (Nanoparticles),Surface Morphology,Laser Ablation
更新于2025-09-16 10:30:52
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Laser ablation in liquids for the assembly of Se@Au chain-oligomers with long-term stability for photothermal inhibition of tumor cells
摘要： For the potential use of Au nanoparticles (NPs) in photothermal therapy, it is important and effective to achieve the uniaxial assembly of Au NPs to allow enhanced absorption in the near infrared (NIR) region. Herein, we first presented the construction of amorphous selenium encapsulated gold (Se@Au) chain-oligomers by successive laser ablation of Au and Se targets in sodium chloride solution without other toxic precursors, stabilizers, or templating molecules. Se@Au chain-oligomers showed evidently enhanced NIR absorption and excellent photothermal transduction efficiency (g), which was higher than 47% at 808 nm. After being stored for 1 year, the Se@Au colloids still exhibited outstanding photothermal performance. The cytotoxicity assay demonstrated that there is negligible toxicity of Se@Au chain-oligomers in cells, but cell viability declined to only 1% in phototherapeutic experiments that were implemented in vitro. In intracellular Reactive Oxygen Species (ROS) generation measurements, Se@Au chain-oligomers could trigger a 35.9% increment of ROS upon laser irradiation. The possible synergetic effects between the anticancer function of Se and photothermal behaviors of Se@Au oligomers were intended to increase ROS level in cells. Therefore, such designed Se@Au chain-oligomers of high stability exhibit promising potential for their use as in vivo photothermal therapeutic agents.
关键词： Laser ablation,Se nanoparticle,Green synthesis,Au nanoparticle,Chain-oligomer,Photothermal therapy
更新于2025-09-16 10:30:52
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Efficacy and safety of radiofrequency, microwave and laser ablation for treating papillary thyroid microcarcinoma: a systematic review and meta-analysis
摘要： Background: To evaluate the efficacy and safety of radiofrequency ablation (RFA), microwave ablation (MWA) and laser ablation (LA) for treating papillary thyroid microcarcinoma (PTMC). Materials and methods: PUBMED and EMBASE were searched for studies on the efficacy and safety of RFA, MWA and LA for treating PTMC. The standard mean difference of the tumor volume before and after therapy and the proportion of complete disappearance, local recurrence, distant metastasis and complications were assessed using both fixed or random-effects modeling. Heterogeneity among studies was determined using the Q statistic for the pooled estimates and the inconsistency index I2. Results: A total of 12 eligible studies, including a sample size of 1187 patients and 1284 PTMCs, were used. RFA, MWA and LA all showed a significant reduction in tumor volume of PTMCs (p < 0.05). Though MWA demonstrated superior efficacy over the other two therapies for volume reduction, the differences were not statistically significant. Additionally, the pooled proportion of complete disappearance after RFA was the highest (76.2%), and the pooled proportion of recurrence for RFA was the lowest (0.01%) among the three therapeutic methods, but no significant difference was detected. There was no event of distant metastasis during the follow-up in all of these studies. Few major complications were encountered; the pooled proportion of complications for RFA (1.73%), MWA (6.0%) and LA (0.92%) was low, revealing no significant differences (p > 0.05). Conclusion: RFA, MWA and LA are acceptable treatments to manage PTMCs in terms of efficacy and safety for non-surgical candidates.
关键词： radiofrequency ablation,Papillary thyroid microcarcinoma,laser ablation,ultrasound,microwave ablation
更新于2025-09-12 10:27:22
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Transperineal laser ablation for percutaneous treatment of benign prostatic hyperplasia: a feasibility study. Results at 6 and 12 months from a retrospective multi-centric study
摘要： Purpose To investigate the effectiveness and safety of SoracteLite?—transperineal percutaneous laser ablation (TPLA) in the treatment of patients with symptomatic benign prostatic hyperplasia (BPH) at 6 and 12 months follow-up. Methods Patients with urinary symptoms secondary to BPH underwent TPLA under local anesthesia in four centers. Under US guidance, up to four 21G applicators were inserted in the prostatic tissue. Each treatment was performed with diode laser operating at 1064 nm changing the illumination time according to prostate size. The primary end-points of this study were change in IPSS, PVR, Qmax, QoL, and prostatic volume at 6 an 12 months from SoracteLiteTM TPLA treatment. Secondary end-point was the assessment of complications. Results Analysis was performed on data 160 patients (mean age 69.8 ± 9.6 years) with at least 6 months follow and of 83 patients (mean age 67.9 ± 8.7 years) with at least 12 months follow-up. At 6 months, IPSS improved from 22.5 ± 5.1 to 7.7 ± 3.3 (P < 0.001), PVR from 89.5 ± 84.6 to 27.2 ± 44.5 ml (P < 0.001), Qmax from 8.0 ± 3.8 to 14.3 ± 3.9 ml/s (P < 0.001), QoL from 4.5 ± 1.1 to 1.8 ± 1.0 (P < 0.001), volume from 75.0 ± 32.4 to 60.3 ± 24.5 ml (P < 0.001). At 12 months, IPSS improved from 22.5 ± 4.5 to 7.0 ± 2.9 (P < 0.001), PVR from 71.7 ± 93.9 to 17.8 ± 51.0 ml (P < 0.001), Qmax from 8.6 ± 5.2 to 15.0 ± 4.0 ml/s (P < 0.001), QoL from 4.2 ± 0.6 to 1.6 ± 0.9 (P < 0.001), volume from 87.9 ± 31.6 to 58.8 ± 22.9 ml (P < 0.001). 7/160 (4.3%) grade I and 1/160 (0.6%) grade III complication occurred. Conclusions SoracteLite? TPLA allows signi?cant improvement of IPSS, Qol, Qmax, PVR, and reduction of prostatic volume at 6 and 12 months.
关键词： Minimally invasive therapy,Benign prostatic hyperplasia,Laser ablation,Transperineal laser ablation,Prostate treatment
更新于2025-09-12 10:27:22
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Fabrication of a ball end nose micro milling tool by tangential laser ablation
摘要： The general trend towards miniaturization of components is leading to an increasing demand for micro cutting tools. Such tools are found in a variety of applications like optics manufacturing, mold machining or medical technology. Indeed, micromachining exhibits a high efficiency, accuracy and low cost in comparison to other micro processing technologies. Micro cutting tools are mostly produced by grinding, a mechanical process, which might damage the tool due to induced forces, vibrations and heat. These detrimental effects cause the high scrap rate in the manufacturing of micro cutting tools and limited geometrical flexibility. A new approach for the manufacturing of micro cutting tools is given by the ultrashort-pulsed laser technology: it enables material removal, which is independent of the hardness of the workpiece material and with only a negligible heat-affected zone. In most cases, laser ablation is disadvantaged in contrast to grinding because of its relatively low material-removal rate. When it comes to the manufacturing of micro cutting tools the small amount of material to be removed makes the ultra-short pulsed laser an interesting alternative to grinding. Furthermore, the laser ablation is a force and wear-free process, which ensures high precision. In this paper, a commercially available micro ball end mill geometry is measured by micro X-ray tomography and 3D microscopy. The movement of the mechanical axes and the path of the laser beam for manufacturing the desired tool are determined based on these measurements. The milling tools with a diameter of 100 μm are produced from cemented carbide blanks, on a 8-axis laser machining center. After machining, the tools are analyzed by SEM and using FIB: By creating a cross section perpendicular to the cutting edge the heat-affected zone is examined. Finally, the cutting tool is successfully applied for the manufacturing of micro electrodes in copper for an EDM process while recording the cutting forces.
关键词： ultrashort pulse laser ablation,tangential laser ablation,ball end nose micro milling tool
更新于2025-09-12 10:27:22
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Laser ablation versus mechanochemical ablation in the treatment of primary varicose veins: A randomized clinical trial
摘要： Objective: to prospectively compare the surgical outcome of using endovenous laser ablation (EVLA) and mechano-chemical ablation (MOCA) in management of patients with primary varicose veins (VV). Methods: The present study prospectively recruited 100 patients with primary VV. They were randomly and equally allocated to one of two treatment group: the EVLA group (n ? 50) or the MOCA group (n ? 50). Before intervention, all patients underwent to clinical and ultrasound assessment of the vascular system. The Venous Clinical Severity Score was used to assess clinical severity. In addition, patients completed the Chronic Venous Insuf?ciency Questionnaire. The primary study outcome was treatment success. After intervention, patients were followed up at 1 week, 1 months, 6 months, and 12 months. Results: Operative success was achieved in all patients. The MOCA group had a signi?cantly shorter operative time when compared with EVLA group. The Venous Clinical Severity Score signi?cantly improved in both groups over the follow-up period and showed signi?cantly lower levels in the MOCA group. Perceived pain was signi?cantly improved in both groups postoperatively with no signi?cant differences. The Chronic Venous Insuf?ciency Questionnaire was signi?cantly improved after 12 months of operation without signi?cant differences between groups. MOCA patients had signi?cantly lower rate of postoperative phlebitis and signi?cantly shorter time to return to work. Conclusions: MOCA for primary VV is a feasible, effective, and safe procedure with better clinical outcome and lower rate of postoperative phlebitis when compared with EVLA.
关键词： Varicose veins,Mechanochemical laser ablation,Endovenous laser ablation
更新于2025-09-12 10:27:22
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Surface ablation efficiency and quality of fs lasers in single-pulse mode, fs lasers in burst mode, and ns lasers
摘要： In recent years, the burst-mode caught a lot of attention in the field of ultrashort-pulse laser micro machining. One of the major issues is the influence of the burst pulse number and frequency on ablation efficiency and quality. A recent publication reported of a significant increase in ablation efficiency when processing with ≥ 25 burst pulses at ≥ 100 MHz burst frequencies. This raises the question of whether processing with such high pulse densities can be attributed to non-thermal ablation, or whether a quasi-nanosecond laser ablation behavior is achieved. To answer this question, we determined ablation efficiencies as function of fluence for silicon, stainless steel, and copper and compared the ablation quality at the optimal fluence using the following laser systems: femtosecond laser operated in single-pulse mode, fs laser operated in 28-pulse-burst mode with a burst pulse frequency of 148 MHz, and a nanosecond laser with a pulse duration of 175 ns, which is identical with the temporal length of the burst pulse train. The comparison showed that the burst mode used produces similar surface morphologies and melt burrs as the nanosecond laser, but at about 2/3 of its efficiency.
关键词： burst mode,ablation efficiency,silicon,laser ablation,copper,steel
更新于2025-09-12 10:27:22
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Prediction of femtosecond laser ablation parameter on Human teeth using chemical compositional analysis
摘要： Laser-based tooth preparation is an emerging non-invasive technique in dentistry. The knowledge about laser ablation parameters is essential for precise removal of lesion or damaged part of the tooth. The present study introduced a novel technique to determine key laser ablation parameters using elemental analysis so that the clinician can readily obtain the optimized laser processing condition. In pursuance of correlating ablation parameters with elemental composition of teeth, a large elemental variation is induced on the dentin and enamel surface by pretreatment using orthophosphoric acid and Carie care gel. The pretreated enamel and dentin surface were irradiated by 800 nm, 100 fs, Ti:Sapphire laser and the elemental analysis were carried out by EDS. Threshold fluence shows the negative correlation with carbon element (C) and shows a positive correlation with Ca and P whereas the converse is true for effective Gaussian beam radius and effective energy penetration depth. The Ca, P and C show good linearity with all ablation parameters. Despite high sensitivity of C, both Ca and P can be the most reliable probe to predict the laser ablation parameters. The method present a simple and straightforward tool to optimize the laser parameter from the non-destructive evaluation of chemical composition even in case of tooth complexity (age, sex and race). In essence, the chemical composition analysis by a suitable probe will improve the precision of laser surgery and reduce the tissue damage in clinical use.
关键词： dentin,Femtosecond laser ablation,enamel,teeth compositional analysis,ablation parameters
更新于2025-09-12 10:27:22
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Weakening of thick steel plates by laser radiation for the removal of hazardous substances
摘要： Hazardous substances such as unexploded ordnance represent a serious threat. It is necessary to develop new methods and equipment for their elimination. For this reason, a laser ablation process is developed where the shell of the objects are weakened in a defined manner to reduce the threat to the environment. This article shows how 25 mm thick steel sheets can be weakened with ablation rates of more than 3000 mm3/min and achieved ablation depths of more than 15 mm by means of an adapted process strategy and an off-axis process gas control. Despite the high incoming process energy, it is ensured that there is no danger to affect the hazardous substances. A critical temperature of 300 °C is not exceeded at the rear surface of the sheet metal.
关键词： thick metal processing,macro metal weakening,laser ablation,high speed ablation
更新于2025-09-12 10:27:22
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Laser and radiofrequency ablations for benign and malignant thyroid tumors
摘要： A growing body of evidence is being published regarding the safety and efficacy of minimally invasive image-guided ablation techniques. While clinical applications of these techniques are increasing, international societies have started to publish treatment guidelines and to make efforts to standardize both terminology and reporting criteria for image-guided thyroid ablations. Laser ablation and radiofrequency ablation (RFA) are among the most common ablation techniques either for benign and malignant thyroid nodules. Unlike laser ablation and RFA in the treatment of benign thyroid nodules, where safety and efficacy have been widely demonstrated, evidence regarding local tumor control of thyroid malignancies is still limited. However, preliminary results are encouraging and image-guided thermal ablation techniques can be considered a valid alternative to surgery for the treatment of benign thyroid nodules and recurrent thyroid cancers. This review evaluates the basic concept of RFA and laser ablations, their techniques, clinical outcomes, and complications based on the suggestions of several society guidelines. Multidisciplinary collaboration remains critical to identify patients which may benefit from minimally invasive image-guided thermal ablations, especially if surgery or radioiodine therapy are not feasible options.
关键词： Thyroid ablation,malignant nodule,RFA,laser ablation,thyroid cancer,benign nodule
更新于2025-09-12 10:27:22