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Reflectance confocal microscopy-guided carbon dioxide laser ablation of low-risk basal cell carcinomas: A prospective study
摘要： Background: Basal cell carcinoma (BCC) treatment modalities can be strati?ed by tumor subtype and recurrence risk. The main limitation of nonsurgical treatment modalities is the lack of histopathologic con?rmation. Re?ectance confocal microscopy (RCM) is a noninvasive imaging device that provides quasihistologic images. Objective: To evaluate the feasibility and ef?cacy of RCM-guided carbon dioxide (CO2) laser ablation of low-risk BCCs. Methods: Prospective study with biopsy specimeneproven low-risk BCCs imaged with RCM. RCM was performed on these sites before and after ablation. If residual tumor was found, a new series of laser passes were performed. The patients were then monitored for recurrence clinically and with RCM. Results: Twenty-two tumor sites in 9 patients (5 men, 4 women) were imaged and treated. Median age was 59 6 12.9 years (range, 30-74 years). Mean tumor size was 7.7 mm (range, 5-10 mm). Residual tumor was identi?ed in 5 of 22 cases (22.7%) under RCM on immediate ?rst-pass postablation sites, prompting additional laser passes. Median follow-up was 28.5 months (range, 22-32 months) with no recurrences found. Conclusions: Addition of RCM to laser ablation work?ow can detect subclinical persistent tumor after initial ablation and may serve as an aid to increase the ef?cacy of laser ablation.
关键词： laser,basal cell carcinoma,carbon dioxide laser,ablation,diagnosis,follow-up,re?ectance confocal microscopy,treatment
更新于2025-09-19 17:13:59
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Treatment of Vocal Fold Polyps with In-Office Potassium Titanyl Phosphate (KTP) Laser Ablation in Professional Singers
摘要： Vocal fold polyp (VFP) is an exophytic gelatinous lesion with an atrophic epithelium. After behavioral and conservative management, phonomicrosurgery is the treatment of choice for VFPs with excellent outcomes in terms of lesion resolution and postoperative vocal function. Office-based potassium titanyl phosphate (KTP) laser ablation is a new treatment modality for VFPs but its efficacy for professional singers has yet to be validated. Reported is a consecutive series of six professional singers (with seven episodes of VFP) who, based on patient and provider preference, underwent in-office KTP laser ablation of VFP. Two polyps required two ablation procedures; otherwise, a single treatment was successful in resolution of VFP at a mean resolution time of 44 days. Singing voice handicap index 10 improved from a mean of 30.8 (range 4?40) to 6.0 (range 0?22). All patients resumed their professional singing careers without vocal limitations. Posttreatment videos were reviewed by three blinded fellowship trained laryngologists, who were not able to accurately predict the laterality of the polyp (52% correct, p = 0.99).
关键词： Singer,Vocal fold polyp,Potassium titanyl phosphate laser,Laser ablation,Vocal fold lesion
更新于2025-09-19 17:13:59
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Effect of liquid environment on single-pulse generation of laser induced periodic surface structures and nanoparticles
摘要： The effect of a liquid environment on the fundamental mechanisms of surface nanostructuring and generation of nanoparticles by single pulse laser ablation is investigated in a closely integrated computational and experimental study. A large-scale molecular dynamics simulation of spatially-modulated ablation of Cr in water reveals a complex picture of dynamic interaction between the ablation plume and water, which involves rapid deceleration of the ablation plume by water environment, formation and prompt disintegration of a hot metal layer at the interface between the ablation plume and water, lateral redistribution and redeposition of a major fraction of the ablation plume, and eventual formation of smooth frozen surface features. A good agreement between the shapes of the surface features predicted in the simulation and the ones generated in single pulse laser ablation experiments performed for Cr in water supports the mechanistic insights revealed in the simulations. The results of this study suggest that the presence of liquid environment can eliminate the sharp features of surface morphology, reduce the amount of material removed from the target by more than an order of magnitude, and narrow down the nanoparticle size distribution as compared to laser ablation in vacuum. Moreover, the computational predictions of the effective incorporation of molecules constituting the liquid environment into the surface region of the irradiated target and the generation of high vacancy concentrations exceeding the equilibrium levels by more than an order of magnitude suggest a potential for hyperdoping of laser-generated surfaces by solutes present in the liquid environment.
关键词： Laser-Induced Periodic Surface Structures (LIPSS),Generation of Nanoparticles,Crystal Defects,Surface Morphology,Hyperdoping,Molecular Dynamics Simulations,Pulsed Laser Ablation in Liquids
更新于2025-09-19 17:13:59
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Experimental X-ray investigations of changes at the “solid-solid interface” boundary after pulsed focused laser irradiation
摘要： Investigated in this work were plates of Zerodur connected to a solid monolith block with the aluminum nanolayer of the 100-nm thickness. The object of the study was this nanolayer that changed its optical transparency under action of pulsed laser radiation. Zerodur plate located on the back side after ablation was step-by-step thinned by grinding and polishing up to the boundary with aluminum nanolayer. After each thinning step, we performed the X-ray phase analysis by using the diffractometer Philips X’Pert PRO – MRD. Used in this study was Cu Kal emission line with the wavelength k = 0.15405980 nm). The anode potential was 45 kV, and current – 40 mA. It has been ascertained that the changes in phase composition are present within the region of 50(cid:1) (cid:1) (cid:1)100 nm from the aluminum nanolayer boundary. It has been found the appearance of the weak but sharp peak at 28.4(cid:1) that corresponds to the re?ection (1 1 1) of cubic silicon nanoparticles. Their size is approximately 12 nm. It was revealed the weakly pronounced but clear peak at 44.78(cid:1) that corresponds to the re?ection (2 0 0) attributed to cubic aluminum.
关键词： Zerodure,Nanoparticles,X-ray techniques,Laser ablation,Thin ?lms,Laser processing
更新于2025-09-19 17:13:59
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Staged Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Hypothalamic Hamartoma: Analysis of Ablation Volumes and Morphological Considerations
摘要： BACKGROUND: Hypothalamic hamartomas (HH) are a challenging pathology that cause gelastic seizures. Magnetic Resonance Imaging-guided Laser Interstitial Thermal Therapy (MRgLITT) offers a safe and effective treatment for HHs via a minimally invasive technique. OBJECTIVE: To determine how clinical outcome correlates to residual tumor volume and surgical strategy by analyzing radiographic data and reconstructing volumetric imaging. METHODS: Clinical and radiographic information of 58 pediatric patients who underwent MRgLITT for HH with at least 6 mo of follow-up were retrospectively reviewed. MR imaging was volumetrically reconstructed to analyze the impact of hamartoma and ablation volumes on outcome. Primary outcome measure was freedom from gelastic seizures. RESULTS: Eighty-one percent of patients were completely free of gelastic seizures at last follow-up; of 22 patients with secondary nongelastic epilepsy, 15 were free of additional seizures. Postoperative complication rate was low. There was no significant difference in gelastic seizure outcome related to pre- or postoperative hamartoma size. Residual hamartoma percentage in those free of gelastic seizures was 43% compared to 71% in those with continued seizures (P = .021). Larger hamartomas required multiple ablations to achieve seizure freedom. CONCLUSION: This large series of patients confirms the safety and efficacy of MRgLITT for pediatric HH and describes morphological considerations that predict success. Our data suggest that complete ablation of the lesion is not necessary, and that the focus should be on appropriate disconnection of the epileptogenic network. We have found that a staged approach to hamartoma ablation allows adequate disconnection of the hamartoma while mitigating risk to surrounding structures.
关键词： Epilepsy,Laser ablation,Hypothalamic hamartoma,Gelastic seizures,Laser interstitial thermal therapy
更新于2025-09-19 17:13:59
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Neurosurgical applications of MRI guided laser interstitial thermal therapy (LITT)
摘要： MRI-guided laser interstitial thermal therapy (LITT) is the selective ablation of a lesion or a tissue using heat emitted from a laser device. LITT is considered a less invasive technique compared to open surgery that provides a non-surgical solution for patients who cannot tolerate surgery. Although laser ablation has been used to treat brain lesions for decades, recent advances in MRI have improved lesion targeting and enabled real-time accurate monitoring of the thermal ablation process. These advances have led to a plethora of research involving the technique, safety, and potential applications of LITT. LITT is a minimally invasive treatment modality that shows promising results and is associated with decreased morbidity. It has various applications, such as treatment of glioma, brain metastases, radiation necrosis, and epilepsy. It can provide a safer alternative treatment option for patients in whom the lesion is not accessible by surgery, who are not surgical candidates, or in whom other standard treatment options have failed. Our aim is to review the current literature on LITT and provide a descriptive review of the technique, imaging findings, and clinical applications for neurosurgery.
关键词： Laser interstitial thermal therapy,Laser ablation
更新于2025-09-19 17:13:59
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IR ns pulsed laser irradiation of Polydimethylsiloxane in vacuum
摘要： Polydimethylsiloxane (PDMS) has been irradiated by a ns pulsed IR laser in vacuum and the radiation effects induced by the coherent radiation, above a threshold fluence, produce a non-equilibrium plasma and material ablation. The laser absorption can be enhanced using gold nanoparticles (AuNPs) embedded in the polymer. The laser-generated plasma has been characterized, whereas the ion emission from both the virgin PDMS and the PDMS t AuNPs sheets has been analysed both in mass and energy. Morphological investigations, optical spectroscopy and compositional analyses have been performed. The adopted laser treatment can be employed to modify the properties of PDMS with and without AuNPs inducing a local enrichment of microcrystalline silicon in both cases.
关键词： Laser ablation,PDMS,TOF,Laser-generated plasma,Polydimethylsiloxane
更新于2025-09-19 17:13:59
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Ultrasonic-Enhanced Fabrication of Metal Nanoparticles by Laser Ablation in Liquid
摘要： Laser ablation in liquid (LAL) is known to be a promising method for synthesizing metal nanoparticles. In this study, gold and silver nanoparticles were fabricated by ultrasonic-assisted LAL. Gold and silver plates were ablated using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a wavelength of 532 nm and energy of 26.4 J cm?2, in distilled water in the presence and absence of an ultrasonic ?eld. The fabricated solution was analyzed with an ultraviolet?visible (UV?vis) nanoparticle colloidal spectrometer, a transmission electron microscope (TEM) with energy-dispersive X-ray spectroscopy (EDS), and ζ-potential measurement. The craters on the silver plates were analyzed by a scanning electron microscope (SEM), a laser microscope, and MATLAB to observe their morphology and calculate the volume to obtain the concentration of the fabricated nanoparticle solution. Optical emissions were observed to study the characteristics of the laser. The results showed that ultrasonic-assisted LAL has considerable potential for fabricating superior metal nanoparticles.
关键词： Silver nanoparticles,Ultrasonic-assisted,Nd:YAG laser,Laser ablation in liquid,Gold nanoparticles
更新于2025-09-19 17:13:59
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Quantitative spatially resolved <i>post-mortem</i> analysis of lithium distribution and transition metal depositions on cycled electrodes <i>via</i> a laser ablation-inductively coupled plasma-optical emission spectrometry method
摘要： Diminishing the loss of performance of lithium ion batteries (LIBs) is a challenge that is yet to be ful?lled. Understanding of deterioration processes and mechanisms (i.e., so-called aging) requires analytically accurate examination of aged cells. Changes in the distribution of lithium or transition metals in the LIB cells can in?uence their cycle and calendar life signi?cantly. As electrochemically treated cells and especially their electrodes do not age homogeneously and the local electrochemistry (e.g. deposition patterns) is strongly dependent on surface properties, bulk analysis is not a satisfactory investigation method. Therefore, a surface sensitive method, namely laser ablation-inductively coupled plasma-optical emission spectrometry (LA-ICP-OES) is presented. LIB cells with lithium metal oxide LiNi1/3Co1/3Mn1/3O2 (NCM111) as cathode material and graphite as anode material are investigated using a 213 nm Nd:YAG laser.
关键词： graphite,aging,laser ablation-inductively coupled plasma-optical emission spectrometry,NCM111,LA-ICP-OES,LIBs,Nd:YAG laser,lithium ion batteries
更新于2025-09-19 17:13:59
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Tailoring Photoluminescence from Si-Based Nanocrystals Prepared by Pulsed Laser Ablation in He-N2 Gas Mixtures
摘要： Using methods of pulsed laser ablation from a silicon target in helium (He)-nitrogen (N2) gas mixtures maintained at reduced pressures (0.5–5 Torr), we fabricated substrate-supported silicon (Si) nanocrystal-based ?lms exhibiting a strong photoluminescence (PL) emission, which depended on the He/N2 ratio. We show that, in the case of ablation in pure He gas, Si nanocrystals exhibit PL bands centered in the “red - near infrared” (maximum at 760 nm) and “green” (centered at 550 nm) spectral regions, which can be attributed to quantum-con?ned excitonic states in small Si nanocrystals and to local electronic states in amorphous silicon suboxide (a-SiOx) coating, respectively, while the addition of N2 leads to the generation of an intense “green-yellow” PL band centered at 580 nm. The origin of the latter band is attributed to a radiative recombination in amorphous oxynitride (a-SiNxOy) coating of Si nanocrystals. PL transients of Si nanocrystals with SiOx and a-SiNxOy coatings demonstrate nonexponential decays in the micro- and submicrosecond time scales with rates depending on nitrogen content in the mixture. After milling by ultrasound and dispersing in water, Si nanocrystals can be used as e?cient non-toxic markers for bioimaging, while the observed spectral tailoring e?ect makes possible an adjustment of the PL emission of such markers to a concrete bioimaging task.
关键词： pulsed laser ablation in gases,pulsed laser deposition,silicon quantum dots,bioimaging,silicon nanoparticles,quantum con?nement,photoluminescence,silicon oxynitride
更新于2025-09-19 17:13:59