Laser Ablation Research Articles

Compression therapy after endovenous laser ablation: Patient compliance and impact on clinical outcome.

This study aimed to investigate the impact of post-interventional compression therapy on clinical outcomes after endovenous laser ablation (EVLA) of incompetent saphenous veins. This prospective, controlled, multicenter study in Germany involved 493 varicose vein patients followed-up for 6months. Compression therapy significantly reduced symptoms compared to no compression (VCSS: 1.4 ± 1.6 vs 2.2 ± 2.2; p = .007). Post-interventional therapy duration of up to 14 days was found to be most effective for improving patient-reported disease severity (p < .001) and higher quality of life (p = .001). Patient compliance was high (82%), and non-compliance was linked to worse disease severity (VCSS 1.4 ± 1.5 vs 2.1 ± 2.3, p = .009). In conclusion, post-interventional compression therapy is beneficial by reducing symptoms and improving quality of life. High patient compliance with the therapy is observed, and non-compliance is associated with worse disease severity.

Fabrication of superhydrophobic, permeable, and anti-reflective porous steel surfaces using laser ablation and heat treatment

Fabrication of superhydrophobic, permeable, and anti-reflective porous steel surfaces using laser ablation and heat treatment

Evaluation of learning curves for contact laser vaporization of the prostate using the 980 nm diode laser for benign prostatic hyperplasia.

We investigated the background of patients who underwent contact laser vaporization of the prostate (CVP) surgery and the learning curve of the operators. A total of 207 patients who underwent CVP surgery for benign prostatic hyperplasia between August 2018 and March 2023 were included in this study. Patient background, perioperative results, pre- and postoperative urinary flow tests, and complications were collected retrospectively. We enrolled 12 doctors who were divided into expert (five doctors) and novice (seven doctors) groups based on the number of TURP experiences before CVP. The median patient age was 73 years (51-92 years) and prostate volume was 56 cc (15-190 cc) with no difference between the expert and novice groups. Complications included urinary retention (eight cases), hematuria (four), urinary tract infection (four), intraoperative perforation (two), and postoperative stricture (one). Both cases of intraoperative perforation occurred in the novice group. The expert group had a significantly shorter operative time (38 vs. 66 min) and a higher operative efficacy of prostate volume divided by operative time (1.43 vs. 0.88 cc/min). Postoperatively, IPSS, quality of life scores, and postvoid residual urine volume decreased, and maximal flow rate increased; however, there was no significant difference between the groups. The expert group showed stable operative time and operative efficacy after about five to eight cases, while the novice group showed stable after about 15 cases. Our findings suggest that CVP was safely performed at our hospital, and operators with limited experience in TURP can achieve stable perioperative results.

Occult retinal neovascularization following intravitreal bevacizumab and laser treatment for retinopathy of prematurity

BackgroundWe present a patient with retinopathy of prematurity (ROP) who developed worsening plus disease after complete regression of stage 3 ROP. The use of fundus fluorescein angiography (FFA) aided the visualization of occult neovascularization that caused the disease progression.Case presentationThe patient was at high risk for ROP due to low birth weight of 690 g and gestational age of 25 weeks. After the diagnosis of stage 3 ROP in zone I without plus disease, she was treated initially with bilateral intravitreal bevacizumab (IVB) and followed by laser photocoagulation 5 weeks later. Despite the resolution of ROP stage, the plus disease worsened. Neither systemic risk factors nor skip laser areas were observed. Hence, FFA was performed and subsequently identified occult neovascularization with active leakage. Additional IVB and laser treatment in the capillary dropout area inside vascularized retina were added. The plus disease improved but mild arteriolar tortuosity persisted.ConclusionsWorsening of plus disease after completion of laser ablation and IVB with complete regression of stage 3 ROP is rare. Systemic risk factors such as continuous oxygen therapy and cardiovascular disease should be ruled out. FFA aided in identifying occult neovascularization and prompted further treatment.

Sub-bandgap photo-response of black silicon fabricated by femtosecond laser irradiation under water

Here we propose a method to fabricate black Si without the need for any chalcogenide doping, accomplished by femtosecond (fs) laser irradiation in a liquid environment, aiming to fabricate the infrared detector and investigating their optoelectronic performance. Multi-scale laser-induced periodical surface structures (LIPSSs), containing micron sized grooves decorated with low spatial frequency ripples on the surface, can be clearly observed by SEM and 3D confocal microscope. The generated black Si demonstrates superior absorption capabilities across a broad wavelength range of 200-2500 nm, achieving an average absorptance of up to 71%. This represents a notable enhancement in comparison to untreated Si, which exhibits an average absorption rate of no more than 20% across the entire detectable spectrum. A metal-semiconductor-metal (MSM) type photodetector was fabricated based on this black Si, demonstrating remarkable optoelectronic properties, specifically, it attains a responsivity of 50.2 mA/W@10 V and an external quantum efficiency (EQE) of 4.02% at a wavelength of 1550 nm, significantly outperforming the unprocessed Si by more than five orders of magnitude. The great enhancement in infrared absorption as well as the optoelectronic performance can be ascribed to the synergistic effect of the multi-scale LIPSSs and the generated intermediate energy levels. On one hand, the multi-scale structures contribute to an anti-reflection and light trapping property; on the other hand, the defects levels generated through fs laser ablation process under water may narrow the band gap of the Si. The results therefore underscore the remarkable potential of black Si processed by fs laser under water for the application of photodetection, especially in the near-infrared band.

Synergistic influence of external electric field on laser ablation in liquid: correlating nanoparticle synthesis and cavitation bubble dynamics

Abstract The present study aims to investigate the changes in the properties of nanoparticles (NPs) and cavitation bubble dynamics on applying an external electric field during laser ablation in liquid (LAL). Investigating electric field assisted laser ablation in liquid (EFLAL) is crucial since phenomena such as plasma charging effect and electrostatic pressure have important role in determining the size, shape, and crystallinity. of the NPs. With this motivation, the present study has been conducted with different electric fields of 0, 100, 500 and 1000 V/cm to probe the effect of an external electric field on the dynamics of EFLAL. The charging effect observed on NPs during cavitation bubble dynamics was also investigated at these field intensities. The size of NPs witnesses a reduction from ~30 nm without electric field to ~19 nm in presence of electric field. Also, a significant narrowing of the size distribution by over 4 times was observed in the presence of electric field. This clearly demonstrates that EFLAL can be used to obtain NPs with uniform size distribution. Moreover, NPs of different shapes have also been observed by varying the electric field intensities (100 and 1000 V/cm). The effect of the external electric field on the dynamics of the cavitation bubble produced during EFLAL has been probed using shadowgraphy technique. It has been observed that the bubble size increases with the presence of an electric field. The estimation of the bubble pressure in the presence of an electric field has revealed that the implosion bubble pressure is significantly lower than pressure in the absence of the field. The results obtained for NPs have been correlated to the changes in bubble parameters in this work.&amp;#xD;

Performance analysis of a liquid lens for laser ablation using OCT imaging

Performance analysis of a liquid lens for laser ablation using OCT imaging

Intraoperative changes in large-scale thalamic circuitry following laser ablation of hypothalamic hamartomas

Background and objectivesGelastic seizures due to hypothalamic hamartomas (HH) are challenging to treat, in part due to an incomplete understanding of seizure propagation pathways. Although magnetic resonance imaging-guided laser interstitial thermal therapy (MRgLITT) is a promising intervention to disconnect HH from ictal propagation networks, the optimal site of ablation to achieve seizure freedom is not known. In this study, we investigated intraoperative post-ablation changes in resting-state functional connectivity to identify large-scale networks associated with successful disconnection of HH. MethodsChildren who underwent MRgLITT for HH at two institutions were consecutively recruited and followed for a minimum of one year. Seizure freedom was defined as Engel score of 1A at the last available follow-up. Immediate pre- and post- ablation resting-state functional MRI scans were acquired while maintaining a constant depth of general anesthetic. Multivariable generalized linear models were used to identify intraoperative changes in large-scale connectivity associated with seizure outcomes. ResultsTwelve patients underwent MRgLITT for HH, five of whom were seizure-free at their last follow-up. Intraprocedural changes in thalamocortical circuitry involving the anterior cingulate cortex were associated with seizure-freedom. Children who were seizure-free demonstrated an increase and decrease in connectivity to the pregenual and dorsal anterior cingulate cortices, respectively. In addition, children who became seizure-free demonstrated increased thalamic connectivity to the periaqueductal gray immediately following MRgLITT. DiscussionSuccessful disconnection of HH is associated with intraoperative, large-scale changes in thalamocortical connectivity. These changes provide novel insights into the large-scale basis of gelastic seizures and may represent intraoperative biomarkers of treatment success.

Transperineal Laser Ablation of the Prostate for Symptomatic Benign Prostatic Hyperplasia: Long-Term Follow-Up in 40 Patients.

To evaluate the long-term efficacy and safety of proprietary transperineal laser ablation (TPLA) of the prostate. Patients with symptomatic benign prostatic hyperplasia underwent TPLA with a 1064-nm continuous-wave diode laser. IPSS, QoL, PVR and prostate volume were evaluated at baseline and successive timepoints. Forty prospectively enrolled patients had post-TPLA follow-up of ≥ 36 months. Median duration of follow-up was 56.5 months (range: 36-76 months). Compared with baseline, the median reduction in IPSS at 12-month follow-up was 74% (interquartile range [IQR]: 60-81%) (P < .001). Median QoL score at 12 months was improved from 5 (IQR: 4-5) at baseline to 1 (IQR: 0-1) (P < .001). Median PVR at 12 months decreased from 108 mL (IQR: 38-178 mL) to 13.5 mL (IQR: 0-40.5 mL) (P < .001), a median reduction of 88% (IQR: 61-100%). At 12 months, median prostate volume was significantly reduced from 66 mL (IQR: 48.5-86.5 mL) to 46 mL (IQR 36-65 mL) (P < .001), a median reduction of 32% (IQR: 21-45%). For all of these parameters, the benefit of TPLA persisted at last follow-up and all changes were statistically significant vs baseline. There were no intraoperative adverse events; perioperative adverse events consisted of one case of prostatitis and one case of urinary tract infection (both mild according to the modified SIR classification system). TPLA for symptomatic BPH produced durable benefits across a range of clinical outcomes and was well tolerated in 56.5 months median duration follow-up.

Au–Si Nanocomposites with High Near-IR Light-to-Heat Conversion Efficiency via Single-Step Reactive Laser Ablation of Porous Silicon for Theranostic Applications

Au–Si Nanocomposites with High Near-IR Light-to-Heat Conversion Efficiency via Single-Step Reactive Laser Ablation of Porous Silicon for Theranostic Applications

Characteristics and antibacterial properties of carbon nanoparticles synthesized by the pulsed laser ablation method in various liquid media

The misuse of conventional antibiotics has led to an upsurge in antibiotic resistance among bacteria. Therefore, it is necessary to develop a new and effective strategy to eradicate bacterial infections. Recent reports have shown the potential of nanoparticles to wield potent antibacterial properties. However, there remains a lack of research done in producing stable nanoparticles for antibacterial applications. Moreover, studies on the effect of various liquid environments in the synthesis of such particles is still limited. Therefore, this study explores carbon nanoparticles synthesized in various liquid media via the pulsed laser ablation method utilitizing an Nd:YAG laser. The laser was focused onto the surface of the graphite plate that is submerged at the bottom of a glass beaker containing different liquid media. Interestingly, the choice of liquid media significantly affected both the physical and antibacterial properties of the produced carbon nanoparticles; nanoparticles synthesized in chitosan solution exhibited greater colloidal stability compared to their counterparts and had a diameter around 38.5 nm, while the ones produced in ethylenediamine were the smallest in size, with a diameter around 29.4 nm. Further examinations revealed that this method yielded high-purity carbon nanoparticles. Antibacterial assessments conducted via the disk diffusion method against E. coli bacteria have also shown that the usage of ethylenediamine during the synthesis procedure greatly improved its antibacterial property. This further confirms the fact that the smaller the nanoparticle is in size, the greater its ability in inhibiting bacterial growth.

Imaging with mass spectrometry: Which ionization technique is best?

The use of mass spectrometry (MS) to acquire molecular images of biological tissues and other substrates has developed into an indispensable analytical tool over the past 25 years. Imaging mass spectrometry technologies are widely used today to study the in situ spatial distributions for a variety of analytes. Early MS images were acquired using secondary ion mass spectrometry and matrix-assisted laser desorption/ionization. Researchers have also designed and developed other ionization techniques in recent years to probe surfaces and generate MS images, including desorption electrospray ionization (DESI), nanoDESI, laser ablation electrospray ionization, and infrared matrix-assisted laser desorption electrospray ionization. Investigators now have a plethora of ionization techniques to select from when performing imaging mass spectrometry experiments. This brief perspective will highlight the utility and relative figures of merit of these techniques within the context of their use in imaging mass spectrometry.

Prognostic outcome of cervical laser ablation using a holmium yttrium-aluminum-garnet (Ho:YAG) laser for the treatment of cervical intraepithelial neoplasia: A single-center retrospective study

Prognostic outcome of cervical laser ablation using a holmium yttrium-aluminum-garnet (Ho:YAG) laser for the treatment of cervical intraepithelial neoplasia: A single-center retrospective study

Synthesis and Antibacterial Activity of Ultrasmall Silver Nanoparticles by Pulsed Laser Ablation in Deionized Water

Background: The main objective of this work is the synthesis and evaluation of silver nanoparticles (Ag NPs) by using pulsed laser ablation of a silver (Ag) target in deionized water and examining their antibacterial activity. Methods: Colloidal solutions of silver nanoparticles were prepared with different pulsed laser energies (620, 880, and 1000) mJ of wavelength 1064 nm and frequency 10 Hz. To determine their structure, optical, morphology, elemental composition, and infrared spectra, the synthesized Ag NPs were characterized using various high-throughput analytical techniques such as (UVVis) spectroscopy, transmission electron microgram (TEM), electron dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectra, and Zeta potential. Results: The results show that the properties of synthesized Ag NPs depend much more on the laser energy. The laser energy can be used to control the properties of the prepared nanoparticles. Uniform distributions of spherical ultrasmall Ag NPs with an average size of (3) nm were obtained suspended in deionized water, which is the most effective size for antibacterial activity. However, the result indicated that the ablated Ag NPs were stable for 4 months in deionized water. The antibacterial activity of the colloidal solution of synthesized Ag NPs against Gramnegative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria was then examined using the agar-well diffusion method. Conclusion: It was found that the prepared nanoparticles exhibited strong activity against E. coli and S. aureus bacteria growth. The average zones of inhibition of Ag NPs were found to be about (26) mm for E. coli and (32) mm for S. aureus bacteria.

Not Entirely in Vein: Predictors of Progressive Chronic Venous Insufficiency and Mediators of Successful Endovenous Laser Ablation

Not Entirely in Vein: Predictors of Progressive Chronic Venous Insufficiency and Mediators of Successful Endovenous Laser Ablation

Comparative study of cell interaction and bacterial adhesion on titanium of different composition, structure and surfaces with various laser treatment

Abstract Titanium and its alloys are commonly used in modern implantology. Cell viability on the surface of titanium implants depends on the surface topography, roughness, and wettability. Laser treatment is a successful method to control the surface morphology.&amp;#xD;The aim of this study was to comprehensively investigate the effects of laser ablation on titanium surfaces and their interactions with cells and bacteria. Cell adhesion, proliferation, and bacterial retention on smooth and laser-textured samples of commercially pure and nanostructured titanium of two grades were evaluated. Femtosecond laser treatment effectively enhances the wettability. Titanium grade four exhibits superior adhesion and proliferation rates when compared to titanium grade two. The cytotoxicity of nanostructured titanium is significantly lower, regardless of the surface treatment. Laser treatment resulted in increased short-term cell proliferation on grade two titanium and long-term cell proliferation on nanostructured grade two titanium only. Although the laser ablation has a limited effect on bacterial adhesion, the coverage of less than 1% in most samples indicates that the material itself has an antibacterial effect on the bacterial strain S. oralis.&amp;#xD;These findings provide valuable insights into how different material structures and surface treatments can affect cellular response and antibacterial properties for potential use in dental implantology.&amp;#xD;

Bronchoscopic treatment of early-stage peripheral lung cancer.

This review article focuses on bronchoscopic treatment of early-stage peripheral lung cancer. Bronchoscopic treatment modalities have garnered considerable attention for early-stage lung cancer. Studies using photodynamic therapy, thermal vapor ablation, laser ablation, cryoablation, and intra-tumoral injection have recently been published. However, the evidence supporting these approaches largely derives from single-arm studies with small sample sizes. Based on the IDEAL-D framework, no technology has progressed passed the idea phase (1). The main weakness of these technologies to date is lack of evidence suggesting they can achieve local control. Presently, no bronchoscopic intervention for lung cancer has sufficient data to warrant its use as part of the standard of care. Despite notable progress, current technologies remain suboptimal, and there is insufficient evidence to support their use outside of a research setting.

Study on nanosecond laser-induced iron plasma reactive etching of single-crystal CVD diamond

Single-crystal diamond has great potential applications in national defense, military, and aerospace fields. However, the high hardness, chemical inertness, and anisotropy bring great challenges to machine microstructures on the diamond. Here, iron plasma, generated by infrared nanosecond laser ablation of a Fe target, was utilized to etch single-crystal diamond. The EDS, Raman, and XPS analysis revealed the formation of iron carbide within the sputtered layer surrounding the diamond microgrooves, thereby confirming that the iron plasma reacts chemically with the diamond. It was observed that employing a reactive metal, such as iron, for etching diamond microgrooves yields improved morphological characteristics and enhanced etching efficiency compared to the use of a non-reactive metal, such as copper. Moreover, the process of material removal through laser-induced iron plasma etching of diamond was elucidated. Subsequently, a systematic investigation was conducted on the impact of processing parameters on the laser-induced iron plasma etching of diamonds. Various periodic microstructures with regular edges and no chipping and cracks were successfully processed on the diamond using suitable laser parameters. This study furnishes a novel approach for the efficient fabrication of high-quality microstructures on single-crystal diamonds.

Influence of a Magnetic Field on the Structure, Morphology and Gas Sensing Characteristics of ZnO: Al Thin Films Prepared by Pulsed Laser Ablation

     In this work, aluminium-doped zinc oxide (AZO) nanostructure at 0.3 wt% and 0.5 wt% Al was synthesized using the pulse-laser ablation technique in liquid(PLAL) using pulsed Nd: YAG laser of a fundamental wavelength of (1064 nm). The process was done in the absence and presence of an external magnetic field. The deposited AZO nanostructures by drop-casting on etched-Si wafers were examined by different techniques. The XRD test illustrates enhancing the crystallinity of the prepared thin films by applying an external magnetic field. The FESEM images displayed the change of nanostructure to nano-sheets of high surface area after using a 77.2 mT permanent magnet placed behind the target during the ablation process. The gas sensor based on the AZO nanostructures has higher sensitivity against NO2 than H2S. Increasing the Al ratio from 0.3 wt% to 0.5 wt% changed the properties of the prepared samples to have small porosity and small surface area, which negatively affected the properties of the sensor

Luminescence in laser-generated functionalized carbon dots

Biocompatible carbon dots (CDs) were obtained by the laser ablation of vegetable carbon in phosphate-buffered saline (PBS) solution. The carbon nanoparticles were generated by an IR laser beam at a 970 nm wavelength with a spot of 200 μm diameter, pulse of 100 ms and of 350 mJ energy, at a 10 Hz repetition rate. The ablation rate, in terms of removed carbon mass per laser shot, was evaluated to be about 5.3 ng. UV–Vis spectroscopy and luminescence measurements were employed to evince the CDs luminescence. The UV excitation at a 365 nm wavelength induces CDs luminescence mainly at about 478 nm and 518 nm giving to the emitted light a characteristic blue-green color. The CDs luminescence in biocompatible solutions is presented and discussed as possible applications to the bio-medical field.