The Role of the Transient Atropisomerism and Chirality of Flurbiprofen Unveiled by Laser-Ablation Rotational Spectroscopy

The combination of atropisomerism and chirality in flurbiprofen is shown to be relevant concerning its pharmacological activity. The two most stable conformers of a total of eight theoretically predicted for each R- or S- flurbiprofen enantiomers have been isolated in the cooling conditions of a supersonic jet and structurally characterized by laser ablation Fourier transform microwave spectroscopy. The detected conformers, whose structure is mainly defined by three dihedral angles, only differ in the sign of the phenyl torsion angle giving rise to S_a and R_a atropisomers. A comparison with the structures available for the R- and S- enantiomers complexed to COX isoforms reveals that the enzymes select only the S_a atropisomers, resulting in a diastereoisomer-specific recognition. The most stable gas phase conformer is exclusively selected when using the S- enantiomer while the second is recognized only for the R- enantiomer. These experimental results highlight the importance of atropisomerism in drug design.

Sensing Properties of g-C3N4/Au Nanocomposite for Organic Vapor Detection

Alleviating the increasingly critical environmental pollution problems entails the sensing of volatile organic compounds (VOCs) as a hazardous factor for human health wherein the development of gas sensor platforms offers an efficient strategy to detect such noxious gases. Nanomaterials, particularly carbon-based nanocomposites, are desired sensing compounds for gas detection owing to their unique properties, namely a facile and affordable synthesis process, high surface area, great selectivity, and possibility of working at room temperature. To achieve that objective, g-C₃N₄ (graphitic carbon nitride) was prepared from urea deploying simple heating. The ensuing porous nanosheets of g-C₃N₄ were utilized as a substrate for loading Au nanoparticles, which were synthesized by the laser ablation method. g-C₃N₄ presented a sensing sensitivity toward organic vapors, namely methanol, ethanol, and acetone vapor gases, which were significantly augmented in the presence of Au nanoparticles. Specifically, the as-prepared nanocomposite performed well with regard to the sensing of methanol vapor gas and offers a unique strategy and highly promising sensing compound for electronic and electrochemical applications.

Epitaxial Lateral Overgrowth of GaN on a Laser-Patterned Graphene Mask

Epitaxial lateral overgrowth (ELO) of GaN epilayers on a sapphire substrate was studied by using a laser-patterned graphene interlayer. Monolayer graphene was transferred onto the sapphire substrate using a wet transfer technique, and its quality was confirmed by Raman spectroscopy. The graphene layer was ablated using a femtosecond laser, which produced well-defined patterns without damaging the underlying sapphire substrate. Different types of patterns were produced for ELO of GaN epilayers: stripe patterns were ablated along the [1¯100]sapphire and [112¯0]sapphire directions, a square island pattern was ablated additionally. The impact of the graphene pattern on GaN nucleation was analyzed by scanning electron microscopy. The structural quality of GaN epilayers was studied by cathodoluminescence. The investigation shows that the laser-ablated graphene can be integrated into the III-nitride growth process to improve crystal quality.

Spacer-Supported Thermal Ablation to Prevent Carbonisation and Improve Ablation Size: A Proof of Concept Study

Thermal ablation offers a minimally invasive alternative in the treatment of hepatic tumours. Several types of ablation are utilised with different methods and indications. However, to this day, ablation size remains limited due to the formation of a central non-conductive boundary layer. In thermal ablation, this boundary layer is formed by carbonisation. Our goal was to prevent or delay carbonisation, and subsequently increase ablation size. We used bovine liver to compare ablation diameter and volume, created by a stand-alone laser applicator, with those created when utilising a spacer between laser applicator and hepatic tissue. Two spacer variants were developed: one with a closed circulation of cooling fluid and one with an open circulation into hepatic tissue. We found that the presence of a spacer significantly increased ablation volume up to 75.3 cm³, an increase of a factor of 3.19 (closed spacer) and 3.02 (open spacer) when compared to the stand-alone applicator. Statistical significance between spacer variants was also present, with the closed spacer producing a significantly larger ablation volume (p < 0.001, M_Diff = 3.053, 95% CI[1.612, 4.493]) and diameter (p < 0.001, M_Diff = 4.467, 95% CI[2.648, 6.285]) than the open spacer. We conclude that the presence of a spacer has the potential to increase ablation size.

Optic nerve head perfusion changes in eyes with proliferative diabetic retinopathy treated with intravitreal ranibizumab or photocoagulation: a randomized controlled trial

Background

Proliferative diabetic retinopathy (PDR) is a serious sight-threatening disease, and half of the patients with high-risk PDR can develop legal blindness within 5 years, if left untreated. This study was aimed at comparing panretinal photocoagulation (PRP) and intravitreal ranibizumab injections in terms of radial peripapillary capillary (RPC) density on optical coherence tomography angiography (OCTA) in patients with treatment-naive PDR.

Methods

This open-label, prospective, randomized clinical trial included 50 patients with treatment-naive PDR with optic disc neovascularization and randomized them into two groups: group 1, with patients undergoing two sessions of PRP 2 weeks apart, and group 2, with patients received three intravitreal ranibizumab injections (0.5 mg) 1 month apart for 3 consecutive months. Patients underwent a full ophthalmological examination, including best-corrected distance visual acuity (BCDVA) measurement in the logarithm of minimal angle of resolution (logMAR) notation and OCTA before intervention and monthly after the last laser session or the first intravitreal ranibizumab injection for 3 months of follow-up. Visual field (VF) was tested at the beginning and end of 3 months.

Results

Forty-two (84%) eyes completed the 3-month follow-up, including 22 eyes in the PRP group (88%) and 20 (80%) eyes in the ranibizumab group. The two groups were comparable in terms of demographic characteristics, diabetes duration, baseline BCDVA, glycated hemoglobin level, OCTA parameters, VF indices, and intraocular pressure (all P > 0.05). The RPC density change from baseline to the 3-month follow-up was significantly lower in the PRP group than in the ranibizumab group (mean difference in RPC density change: - 3.61%; 95% confidence interval: - 5.57% to - 1.60%; P = 0.001). The median (interquartile range) logMAR change from baseline to the 3-month follow-up (0.0 [0.2]) was significantly higher in the PRP group than in the ranibizumab group (- 0.15 [0.3]; P < 0.05). The median changes in central foveal thickness from baseline to the 3-month follow-up differed significantly between the two groups (P = 0.001).

Conclusions

In eyes with PDR and neovascularization of the disc RPC density on OCTA increased in the ranibizumab group and decreased in the PRP group. Visual acuity gain was higher in the ranibizumab group than in the PRP group. Future multicenter trials addressing our limitations are required to verify the findings of this study.

Ultrasound-guided percutaneous laser ablation for papillary thyroid microcarcinoma: a literature review

The incidence of papillary thyroid microcarcinoma has been increasing worldwide. However, the optimal management strategy remains a topic of discussion and varies from an active follow-up to a thyroidectomy. New thermoablation techniques for selected cases seem to be sufficiently effective but minimally invasive. One of the newest thermoablation methods is ultrasound-guided percutaneous laser ablation. There are already some data showing promising results of this method in the management of papillary thyroid microcarcinomas. In this article, we review recent papers and conclude on the current status of the ultrasound-guided percutaneous laser ablation technique for the management of papillary thyroid microcarcinomas.

Dynamics and Processes on Laser-Irradiated Surfaces

The modification of solid surfaces via the impacts of intense laser pulses and the dynamics of the relevant processes are reviewed. We start with rather weak interactions on dielectric materials, based on non-linear absorption across the bandgap and resulting in low-level local effects like electron and individual ion emission. The role of such locally induced defects in the cumulative effect of incubation, i.e., the increase in efficiency with the increasing number of laser pulses, is addressed. At higher excitation density levels, due to easier laser-material coupling and higher laser fluence, the energy dissipation is considerable, leading to lattice destabilization, surface relaxation, ablation, and surface modification (e.g., laser-induced periodic surface structures). Finally, a short list of possible applications, namely in the field of wettability, is presented.

Stereotactic needle biopsy and laser ablation of geographically distinct lesions through a novel magnetic resonance imaging-compatible cranial stereotaxic frame: illustrative case

BACKGROUND

Current technologies that support stereotactic laser ablation (SLA) of geographically distinct lesions require placement of multiple bolts or time-consuming, intertrajectory adjustments.

OBSERVATIONS

Two geographically distinct nodular lesions were safely biopsied and laser ablated in a 62-year-old woman with recurrent glioblastoma using the ClearPoint Array frame, a novel magnetic resonance imaging-compatible stereotactic frame designed to support independent parallel trajectories without intertrajectory frame adjustment.

LESSONS

Here, the authors provide a proof-of-principle case report demonstrating that geographically distinct lesions can be safely biopsied and ablated through parallel trajectories supported by the ClearPoint Array frame without intertrajectory adjustment.

Surface Feature Prediction for Laser Ablated 40Cr13 Stainless Steel Based on Extreme Learning Machine

Determining an optimal combination of laser process parameters can significantly improve the efficiency and quality of 40Cr13 steel surface processing. In this study, two machine learning models (ELMSS and ELMPS) were proposed to predict the processing results of surface features to optimize process parameters. The prediction accuracies of the proposed models were always higher than those of traditional back propagation (BP) and radial basis function (RBF) neural networks, and the calculation time of the proposed models was significantly reduced. In comparison, the prediction accuracy ranking for ablation depth was ELMSS (92.6%), BP (89.8%), and RBF (89.6%), and for the ablation width, it was ELMSS (98.3%), BP (97.4%), and RBF (96.1%). The material removal rate was 92.4%, 91.1%, and 89.1% for ELMSS, BP, and RBF, respectively. Finally, the prediction accuracy ranking for surface roughness was 86.8%, 80.7%, and 79.5% for ELMPS, BP, and RBF, respectively. After optimization by the genetic algorithm, the prediction accuracies of the proposed models for the depth, width, material removal rate, and surface roughness reached 94.0%, 99.0%, 93.2%, and 91.2%, respectively. With the support of ELMSS and ELMPS, the results of the surface features can be predicted before machining and the appropriate process parameters can be selected in advance.

Completion of disconnective surgery for refractory epilepsy in pediatric patients using robot-assisted MRI-guided laser interstitial thermal therapy

OBJECTIVE

Since 2007, the authors have performed 34 hemispherotomies and 17 posterior quadrant disconnections (temporoparietooccipital [TPO] disconnections) for refractory epilepsy at Sant Joan de Déu Barcelona Children's Hospital. Incomplete disconnection is the main cause of surgical failure in disconnective surgery, and reoperation is the treatment of choice. In this study, 6 patients previously treated with hemispherotomy required reoperation through open surgery. After the authors' initial experience with real-time MRI-guided laser interstitial thermal therapy (MRIgLITT) for hypothalamic hamartomas, they decided to use this technique instead of open surgery to complete disconnective surgeries. The objective was to report the feasibility, safety, and efficacy of MRIgLITT to complete hemispherotomies and TPO disconnections for refractory epilepsy in pediatric patients.

METHODS

Eight procedures were performed on 6 patients with drug-resistant epilepsy. Patient ages ranged between 4 and 18 years (mean 10 ± 4.4 years). The patients had previously undergone hemispherotomy (4 patients) and TPO disconnection (2 patients) at the hospital. The Visualase system assisted by a Neuromate robotic arm was used. The ablation trajectory was planned along the residual connection. The demographic and epilepsy characteristics of the patients, precision of the robot, details of the laser ablation, complications, and results were prospectively collected.

RESULTS

Four patients underwent hemispherotomy and 2 underwent TPO disconnection. Two patients, including 1 who underwent hemispherotomy and 1 who underwent TPO disconnection, received a second laser ablation because of persistent seizures and connections after the first treatment. The average precision of the system (target point localization error) was 1.7 ± 1.4 mm. The average power used was 6.58 ± 1.53 J. No complications were noted. Currently, 5 of the 6 patients are seizure free (Engel class I) after a mean follow-up of 20.2 ± 5.6 months.

CONCLUSIONS

According to this preliminary experience, laser ablation is a safe method for complete disconnective surgeries and allowed epilepsy control in 5 of the 6 patients treated. A larger sample size and longer follow-up periods are necessary to better assess the efficacy of MRIgLITT to complete hemispherotomy and TPO disconnection, but the initial results are encouraging.

Ablative Therapies for Breast Cancer: State of Art

Breast cancer (BC) is the most frequently diagnosed malignancy among women. In the past two decades, new technologies and BC screening have led to the diagnosis of smaller and earlier-stage BC (ESBC). Therefore, percutaneous minimally invasive techniques (PMIT) were adopted to treat patients unfit for surgery, women who refuse it, or elderly patients with comorbidities that could make surgery a difficult and life-threatening treatment. The target of PMIT is small-size ESBC with the scope of obtaining similar efficacy as surgery. Minimally invasive treatments are convenient alternatives with promising effectiveness, lower morbidity, less cost, less scarring and pain, and more satisfying cosmetic results. Ablative techniques used in BC are cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused ultrasound (US), and laser ablation. The aim of our study is to discuss the current status of percutaneous management of BC, evaluate the clinical outcomes of PMIT in BC, and analyze future perspectives regarding ablation therapy in BC.

Transperineal laser ablation as a new minimally invasive surgical therapy for benign prostatic hyperplasia: a systematic review of existing literature

Introduction

Transperineal laser ablation (TPLA) of the prostate is a new, minimally invasive technique for benign prostatic hyperplasia (BPH) with promising effectiveness and safety outcomes. This systematic review aims to provide an update of existing literature.

Methods

A literature review was performed in Pubmed/MEDLINE, Embase, Cochrane Library, and clinicaltrials.gov from January 2000 up to April 2023. Data extraction and risk of bias were performed independently by three authors.

Results

A total of 11 studies were included, among which 9 were observational, 1 randomized controlled trial, 1 animal study, while 2 of them were comparative (1 with prostatic artery embolization and 1 with transurethral resection of the prostate). Functional outcomes were improved in the majority of studies both for objective (maximum flow rate and post-void residual) and subjective outcomes (improvement of International Prostate Symptom Score and quality of life). Complication rates ranged between 1.9% and 2.3% for hematuria, 3.7% and 36.3% for dysuria, 1.9% and 19% for acute urinary retention, 0.6% and 9.1% for orchitis/urinary tract infections, and 0.6% and 4.8% for prostatic abscess formation. Regarding sexual function, >95% of patients retained their ejaculation while erectile function was maintained or improved.

Conclusion

TPLA of the prostate is an innovative, minimally invasive technique for managing patients with BPH. Existing studies indicate an effective technique in reducing International Prostate Symptom Score and quality of life scores, post-void residual reduction, and increase in Qmax, albeit the measured improvements in terms of Qmax are not equal to transurethral resection of the prostate. Although sexual function is maintained, the mean catheterization time is 7 days, and no long-term data are available for most patients.

Highly Stable Sb/C Anode for K+ and Na+ Energy Storage Enabled by Pulsed Laser Ablation and Polydopamine Coating

Potassium- and sodium-ion batteries (PIBs and SIBs) have great potential as the next-generation energy application owing to the natural abundance of K and Na. Antimony (Sb) is a suitable alloying-type anode for PIBs and SIBs due to its high theoretical capacity and proper operation voltage; yet, the severe volume variation remains a challenge. Herein, a preparation of N-doped carbon-wrapped Sb nanoparticles (L-Sb/NC) using pulsed laser ablation and polydopamine coating techniques, is reported. As the anode for PIB and SIB, the L-Sb/NC delivers superior rate capabilities and excellent cycle stabilities (442.2 and 390.5 mA h g^-1 after 250 cycles with the capacity decay of 0.037% and 0.038% per cycle) at the current densities of 0.5 and 1.0 A g^-1 , respectively. Operando X-ray diffraction reveals the facilitated and stable potassiation and sodiation mechanisms of L-Sb/NC enabled by its optimal core-shell structure. Furthermore, the SIB full cell fabricated with L-Sb/NC and Na₃ V₂ (PO₄ )₂ F₃ shows outstanding electrochemical performances, demonstrating its practical energy storage application.

Interaction Energy Dependency on Pulse Width in ns NIR Laser Scanning of Silicon

Laser ablation of semiconductor silicon has been extensively studied in the past few decades. In the ultrashort pulse domain, whether in the fs scale or ps scale, the pulse energy fluence threshold in the ablation of silicon is strongly dependent on the pulse width. However, in the ns pulse scale, the energy fluence threshold dependence on the pulse width is not well understood. This study elucidates the interaction energy dependency on pulse width in ns NIR laser ablation of silicon. The level of ablation or melting was determined by the pulse energy deposition rate, which was proportional to laser peak power. Shorter pulse widths with high peak power were likely to induce surface ablation, while longer pulse widths were likely to induce surface melting. The ablation threshold increased from 5.63 to 24.84 J/cm² as the pulse width increased from 26 to 500 ns. The melting threshold increased from 3.33 to 5.76 J/cm² as the pulse width increased from 26 to 200 ns, and then remained constant until 500 ns, the longest width investigated. Distinct from a shorter pulse width, a longer pulse width did not require a higher power level for inducing surface melting, as surface melting can be induced at a lower power with the longer heating time of a longer pulse width. The line width from surface melting was less than the focused spot size; the line appeared either as a continuous line at slow scanning speed or as isolated dots at high scanning speed. In contrast, the line width from ablation significantly exceeded the focused spot size.

The Conformations of Isolated Gallic Acid: A Laser-Ablation Rotational Study

The rotational spectrum of laser-ablated gallic acid has been recorded using CP-FTMW spectroscopy. Two rotamers have been detected, and their rotational spectra have been assigned and analyzed to obtain the molecular spectroscopic parameters. The observed rotamers have been unambiguously identified in the light of theoretical computations, based on the comparison of the experimental line intensities and rotational parameters with the rotational constants and electric dipole moments predicted from theoretical calculations. The values of the planar inertial moments confirm that the observed conformers are planar, and their relative stability and population have been determined from relative intensity measurements. The B3LYP-D3/6-311++G(2d,p) level has been shown to be the best method among a series of levels normally used to predict the rotational parameters in rotational spectroscopy. In the observed conformers, the three adjacent OH groups are arranged in a sequential form, and the only difference between them lies in the orientation of the COOH group. Although weak attractive OH···O interactions seem to exist, the analysis of the electron density topology does not show the existence of any critical point corresponding to these interactions.

Magnetic resonance imaging-guided laser interstitial thermal therapy for complete corpus callosotomy: technique and 1-year outcomes. Patient series

BACKGROUND

Magnetic resonance imaging (MRI)-guided stereotactic laser interstitial thermal therapy (LITT) is a minimally invasive technique that has been described for the treatment of certain forms of epilepsy through partial or complete callosotomy, with few cases describing single-stage complete LITT callosotomy. The authors aimed to demonstrate this technique's feasibility and efficacy through description of the technique and 1-year outcomes in 3 cases of single-stage complete LITT callosotomy in patients with anatomically normal corpa callosa (CCs).

OBSERVATIONS

The patients were aged 14-27 years and experienced atonic seizures. Completeness of callosotomy was determined from MRI scans obtained >3 months after LITT procedures. The estimated ablations of the CC were 94%, 89%, and 100%, respectively. The second patient had a catheter breach the lateral ventricle, resulting in the lowest estimated percentage of ablation in this series (89%), with minimal atonic seizure reduction. The first patient had significant reduction in atonic seizure frequency, and the third patient had complete resolution of atonic seizures. None of the patients experienced any long-term complications. Intensive care length of stay was 1 night for each patient, and total length of stay was between 2 and 7 nights. Postoperative follow-up was between 14 and 18 months.

LESSONS

Complete laser callosotomy is achievable and is a safe alternative to microsurgical or endoscopic approaches.

Tissue harvest with a laser microbiopsy

Significance

Traditional pathology workflow suffers from limitations including biopsy invasiveness, small fraction of large tissue samples being analyzed, and complex and time-consuming processing.

Aim

We address limitations of conventional pathology workflow through development of a laser microbiopsy device for minimally invasive harvest of sub-microliter tissue volumes. Laser microbiopsy combined with rapid diagnostic methods, such as virtual hematoxylin and eosin (H&E) imaging has potential to provide rapid minimally invasive tissue diagnosis.

Approach

Laser microbiopsies were harvested using an annular shaped Ho:YAG laser beam focused onto the tissue surface. As the annulus was ablated, the tissue section in the center of the annulus was ejected and collected directly onto a glass slide for analysis. Cryogen spray cooling was used before and after laser harvest to limit thermal damage. Microbiopsies were collected from porcine skin and kidney. Harvested microbiopsies were imaged with confocal microscopy and digitally false colored to provide virtual H&E images.

Results

Microbiopsies were successfully harvested from porcine skin and kidney. Computational and experimental results show the benefit of cryogen pre- and post-cooling to limit thermal damage. Virtual H&E images of microbiopsies retained observable cellular features including cell nuclei.

Conclusions

Laser microbiopsy with virtual H&E imaging shows promise as a potential rapid and minimally invasive tool for biopsy and diagnosis.

The copper transporter CTR1 and cisplatin accumulation at the single-cell level by LA-ICP-TOFMS

More than a decade ago, studies on cellular cisplatin accumulation via active membrane transport established the role of the high affinity copper uptake protein 1 (CTR1) as a main uptake route besides passive diffusion. In this work, CTR1 expression, cisplatin accumulation and intracellular copper concentration was assessed for single cells revisiting the case of CTR1 in the context of acquired cisplatin resistance. The single-cell workflow designed for in vitro experiments enabled quantitative imaging at resolutions down to 1 µm by laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS). Cisplatin-sensitive ovarian carcinoma cells A2780 as compared to the cisplatin-resistant subline A2780cis were investigated. Intracellular cisplatin and copper levels were absolutely quantified for thousands of individual cells, while for CTR1, relative differences of total CTR1 versus plasma membrane-bound CTR1 were determined. A markedly decreased intracellular cisplatin concentration accompanied by reduced copper concentrations was observed for single A2780cis cells, along with a distinctly reduced (total) CTR1 level as compared to the parental cell model. Interestingly, a significantly different proportion of plasma membrane-bound versus total CTR1 in untreated A2780 as compared to A2780cis cells was observed. This proportion changed in both models upon cisplatin exposure. Statistical analysis revealed a significant correlation between total and plasma membrane-bound CTR1 expression and cisplatin accumulation at the single-cell level in both A2780 and A2780cis cells. Thus, our study recapitulates the crosstalk of copper homeostasis and cisplatin uptake, and also indicates a complex interplay between subcellular CTR1 localization and cellular cisplatin accumulation as a driver for acquired resistance development.

Progress in Laser Ablation and Biological Synthesis Processes: "Top-Down" and "Bottom-Up" Approaches for the Green Synthesis of Au/Ag Nanoparticles

Because of their small size and large specific surface area, nanoparticles (NPs) have special properties that are different from bulk materials. In particular, Au/Ag NPs have been intensively studied for a long time, especially for biomedical applications. Thereafter, they played a significant role in the fields of biology, medical testing, optical imaging, energy and catalysis, MRI contrast agents, tumor diagnosis and treatment, environmental protection, and so on. When synthesizing Au/Ag NPs, the laser ablation and biosynthesis methods are very promising green processes. Therefore, this review focuses on the progress in the laser ablation and biological synthesis processes for Au/Ag NP generation, especially in their fabrication fundamentals and potential applications. First, the fundamentals of the laser ablation method are critically reviewed, including the laser ablation mechanism for Au/Ag NPs and the controlling of their size and shape during fabrication using laser ablation. Second, the fundamentals of the biological method are comprehensively discussed, involving the synthesis principle and the process of controlling the size and shape and preparing Au/Ag NPs using biological methods. Third, the applications in biology, tumor diagnosis and treatment, and other fields are reviewed to demonstrate the potential value of Au/Ag NPs. Finally, a discussion surrounding three aspects (similarity, individuality, and complementarity) of the two green synthesis processes is presented, and the necessary outlook, including the current limitations and challenges, is suggested, which provides a reference for the low-cost and sustainable production of Au/Ag NPs in the future.

Long-term outcomes of endoscopic ultrasound-guided laser ablation for liver tumors in the caudate lobe: 5 years of experience

OBJECTIVES

Liver tumor in the caudate lobe is challenging to treat, partly due to its deep location. Endoscopic ultrasound-guided laser ablation (EUS-LA) is a new attractive option for tumors in high-risk or difficult-to-reach locations. This prospective study investigated the long-term efficacy of EUS-LA for tumors in the caudate lobe, and factors that predict outcomes.

METHODS

From June 2016 to July 2021, twenty consecutive patients (aged 56.95 ± 10.06 years) with 25 caudate lobe tumors (15.64 ± 6.37 mm) underwent EUS-LA. Treatment outcomes were assessed and predictive factors were calculated via univariate and multivariate analyses.

RESULTS

Twenty-five tumors achieved complete ablation after the first or second session of EUS-LA. The treatment effectiveness was 100%. During a median follow up of 27 months (3-60), four tumors (16%) developed local tumor progression and 15 patients (75%) experienced intrahepatic distant recurrence. According to univariate and multivariate analyses, the significant prognostic factor of local tumor progression was tumor size >2 cm (p = 0.047). Significant prognostic factors of intrahepatic distant recurrence were: tumor number, alpha-fetoprotein level, and total bilirubin level (p = 0.020, 0.019, 0.010, respectively). No adverse events related to EUS-LA were observed.

CONCLUSION

EUS-LA is a viable, safe, and effective treatment option for patients with liver tumor in the caudate lobe. Tumor size >2 cm increases the risk of post-procedural local tumor progression. Intrahepatic tumor number, and pretreatment alpha-fetoprotein level and total bilirubin level are associated with intrahepatic distant recurrence.

REGISTRATION

Clinicaltrials.gov, ID: NCT02816944(June 29, 2016).

On-the-Fly Short-Pulse R2R Laser Patterning Processes for the Manufacturing of Fully Printed Semitransparent Organic Photovoltaics

Ultrafast laser patterning is an essential technology for the low-cost and large area production of flexible Organic Electronic (OE) devices, such as Organic Photovoltaics (OPVs). In order to unleash the potential of ultrafast laser processing to perform the selective and high precision removal of complex multilayers from printed OPV stacks without affecting the underlying nanolayers, it is necessary to optimize its parameters for each nanolayer combination. In this work, we developed an efficient on-the-fly picosecond (ps) laser scribing process (P1, P2 and P3) using single wavelength and single step/pass for the precise and reliable in-line patterning of Roll-to-Roll (R2R) slot-die-coated nanolayers. We have investigated the effect of the key process parameters (pulse energy and overlap) on the patterning quality to obtain high selectivity on the ablation of each individual nanolayer. Finally, we present the implementation of the ultrafast laser patterning process in the manufacturing of fully R2R printed flexible semitransparent OPV modules with a 3.4% power conversion efficiency and 91% Geometric Fill Factor (GFF).

Organic Solar Cells Improved by Optically Resonant Silicon Nanoparticles

Silicon nanophotonics has become a versatile platform for optics and optoelectronics. For example, strong light localization at the nanoscale and lack of parasitic losses in infrared and visible spectral ranges make resonant silicon nanoparticles a prospect for improvement in such rapidly developing fields as photovoltaics. Here, we employed optically resonant silicon nanoparticles produced by laser ablation for boosting the power conversion efficiency of organic solar cells. Namely, we created colloidal solutions of spherical nanoparticles with a range of diameters (80-240 nm) in different solvents. We tested how the nanoparticles' position in the device, their concentration, silicon doping, and method of deposition affected the final device efficiency. The best conditions optimization resulted in an efficiency improvement from 6% up to 7.5%, which correlated with numerical simulations of nanoparticles' optical properties. The developed low-cost approach paves the way toward highly efficient and stable solution-processable solar cells.

The Antimicrobial Effect of Gold Quantum Dots and Femtosecond Laser Irradiation on the Growth Kinetics of Common Infectious Eye Pathogens: An In Vitro Study

We studied the antimicrobial effect of gold quantum dots (AuQDs), femtosecond laser irradiation, and the combined effect of laser irradiation and AuQD treatment against common infectious eye pathogens. The INSPIRE HF100 laser system (Spectra Physics) provided a femtosecond laser, which was pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP (Spectra Physics), while a Quanta-Ray nanosecond Nd: YAG laser (Spectra-Physics) was used to precisely synthesize 7.8, 8.7, and 11.6 nm spherical AuQDs. Then, the in vitro growth kinetics and growth rate analysis of E. coli, methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes, and Candida albicans (treated with the AuQDs, femtosecond laser irradiation, or combined laser and AuQDs treatment) was measured. The biocompatibility of the AuQDs with the retinal epithelial cell lines (ARPE-19) and their toxicity to the cells was assayed. The results showed that (1) in vitro irradiation using a 159 J/cm² energy density obtained from the 400 nm femtosecond laser suppressed the growth of each of the five pathogens. (2) Similarly, treatment with the AuQDs was antimicrobial against the four bacteria. The AuQDs with an average size of 7.8 nm were more highly antimicrobial and biocompatible and were less cytotoxic than the larger AuQD sizes. (3) The combined femtosecond laser irradiation and AuQD treatment was more highly antimicrobial than each treatment alone. (4) The AuQD treatment did not impair the rate of wound closure in vitro. These findings suggest that combined femtosecond laser irradiation and AuQD treatment is significantly antimicrobial against Candida albicans, Gram-positive L. monocytogenes, S. aureus, and E. faecalis, as well as Gram-negative E. coli. The nontoxicity and biocompatibility of the AuQD particles tested suggest that this form of treatment may be clinically viable.

Fabrication and Characterization of Au-Decorated MCM-41 Mesoporous Spheres Using Laser-Ablation Technique

This study reports the synthesis of Au-decorated MCM-41 mesoporous nanoparticles using a laser-ablation technique. It was observed that the number of Au attached to MCM-41 nanostructures was dependent on the amount of encapsulated Cationic surfactant (cetyl ammonium bromide (CTAB) volume. The chemical group of the prepared nanoparticles was analyzed by FT-IR spectroscopy, where different absorption peaks corresponding to Au and MCM-41 were observed. The observed band region was ∼1090, 966, 801, 2918, and 1847 cm^-1 for different samples, clearly confirming the successful preparation of MCM-41 with CTAB and Au-decorated MCM-41 nanoparticles using environmentally friendly laser-ablation approach. The surface morphology of the prepared nanoparticles were performed using TEM techniques. The TEM analysis of the MCM-41 specimen showed silica spheres with an average size of around 200 nm. Furthermore, Raman spectroscopy was done to evaluate the chemical structure of the prepared nanoparticles. It was seen that the prepared Au NPs decorated the MCM-41 system facilitated strong Raman peaks of CTAB. In addition, eight distinct Raman peaks were observed in the presence of Au NPs. This new functionalized method using the laser-ablation approach for mesoporous nanoparticles will participate effectively in multiple applications, especially the encapsulated molecule sensing and detection.

Comparison of 5-year outcomes and quality of life between endovenous laser (980 nm) and microwave ablation combined with high ligation for varicose veins

Our study aims to evaluateand compare the long-term results of endovenous laser (EVLA) and microwave ablation (EMA) combined with high ligation in treating varicose veins (VVs). A total of 122 patients (150 legs) underwent EMA combined with high ligation, and 127 patients (167 legs) underwent EVLA procedures (980 nm) combined with high ligation in this retrospective study. Outcomes included the Aberdeen Varicose Vein Questionnaire (AVVQ) score, the Venous Clinical Severity Score (VCSS), clinical recurrence of VVs and patient satisfaction duringthe 5-year follow-up.During the 5-year follow-up, patients who underwent the EVLA procedure showed a higher recurrence of VVs than those who underwent the EMA procedure (22.75% vs. 13.33%, P = 0.03, odds ratio (OR): 1.91, 95% confidence interval (CI): 1.06-3.45), especially at the primary site (6% vs. 14.37%, P = 0.01; OR: 2.63; 95% CI: 1.21-5.72). VV recurrence within 3 years was higher in patients who underwent EVLA than in those who underwent the EMA procedure (73.68% vs. 40%, P = 0.01; OR: 4.2; 95% CI: 1.37-12.86). Compared with those at baseline, the AVVQ score, VCSS and EQ-5D score improved significantly at 5 years for patients who underwent either procedure (P < 0.01); however, the VCSS and AVVQ score were higher for patients who underwent the EVLA procedure (P = 0.05). The patient reintervention rate was higher for EVLA than for EMA (14.79% vs. 7.33%, P = 0.033; OR: 2.19; 95% CI: 2.06-5.34). Our results confirmed that EMA and EVLA improve the QoL of patients and that EMA combined with high ligation demonstrates lower 5-year recurrence, especially at primary sites.