Dual Laser Ablation Research Articles

Dual laser ablation process assisted the synthesis of titanium dioxide and graphene oxide nanoparticles embedded in chitosan for electrical applications

Nanosecond laser ablation was used to prepare and develop chitosan (Cs) with both TiO2 nanoparticles and Cs/TiO2 various contents of graphene oxide (GO) to improve the characterization of the Cs/TiO2-GO nanocomposites. The XRD peaks were indexed according to the typical anatase with a tetragonal structure of TiO2. No peaks were observed in GO demonstrating that GO was destructed by the intermolecular hydrogen bonds and the crystalline regions in chitosan. Scherer's formula estimated the mean particle size (nearly 26 ± 4 nm). The major bands of chitosan and TiO2 were detected in FT-IR spectra. After the addition of GO, the IR spectra were similar because of the superposition of the carbon bands shared between GO and chitosan. Maxwell-Wagner model was used to explain the causes of the higher values of dielectric loss (ε′′), and dielectric loss (ε′′). The increase in the value of tan δ in low frequencies region was because of the ohmic elements' predominance in the nanocomposites samples' capacitive nature. The tan δ increases with raising frequencies and then gradually decreases. The Cole-Cole diagram illustrates a half-circle shape that describes contact effects and Debye model relaxation approach.

ZnSn(OH)6 nanocube/ Zn2SnO4 nanowires yolk–shell hierarchical structure with tunable band gap for deep-UV photodetection

Ternary oxides nanomaterials (TONs) are the mostly investigated as a promising candidate for ultraviolet detection due to its excellent photoconductivity. Among them, Zn2SnO4 (ZTO) has received extensive attention, but its advantages cannot be utilized in deep-ultraviolet (DUV) detection due to band gap limitation. Herein, we synthesized ZnSn(OH)6 nanocube/ ZTO nanowires yolk–shell hierarchical structure with tunable band gap between 3.6 and 4.4 eV by the dual laser ablation in liquid plus hydrothermal method. This hierarchical structure is applied to DUV photodetection and the results showed that it could improve the Ilight/ Idark ratio of ZTO DUV photodetection by two orders of magnitude while retaining the advantage of ZTO’s rapid response time (τrise =0.43 ms, τdecay =0.55 ms). Moreover, deep-UV imaging is also realized based on this material. This approach provides a new way of tuning the TONs’ band gap and its application to DUV photodetection or imaging.

MP40-13 ARE METACHRONOUS BLADDER TUMORS PREDICTIVE OF UPPER TRACT UROTHELIAL CARCINOMA RECURRENCE IN PATIENTS TREATED WITH RADICAL OR ENDOSCOPIC SURGERY

You have accessJournal of UrologyCME1 May 2022MP40-13 ARE METACHRONOUS BLADDER TUMORS PREDICTIVE OF UPPER TRACT UROTHELIAL CARCINOMA RECURRENCE IN PATIENTS TREATED WITH RADICAL OR ENDOSCOPIC SURGERY Christian Ericson, Anthony Compton, Bryce Baird, and Raymond Pak Christian EricsonChristian Ericson More articles by this author , Anthony ComptonAnthony Compton More articles by this author , Bryce BairdBryce Baird More articles by this author , and Raymond PakRaymond Pak More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002600.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Upper tract urothelial carcinoma (UTUC) comprises 5% of urothelial cancers. Treatment with nephroureterectomy or endoscopically with ureteroscopy with dual laser ablation using holmium and neodymium fibers are current management strategies. Regular surveillance for recurrence is performed post operatively with cross sectional imaging or by ureteroscopy. Metachronous bladder tumors are often identified during surveillance and there is paucity of literature defining their role in predicting upper tract recurrence of UTUC. METHODS: Data was collected from a total of 127 patients who were treated for upper tract urothelial carcinoma (UTUC) with either nephroureterectomy or endoscopic management from 2016 to 2020. Patients underwent surveillance for a maximum of 48 months and the rates of upper tract recurrence (ipsilateral or contralateral) were recorded. Patients were separated into groups based on the presence or absence of metachronous bladder tumors (MBT). The rates of upper tract recurrence overall as well as solely in the contralateral kidney were compared in the two groups. A Pearson’s chi-squared test was utilized to determine statistical significance of the two groups. A p-value of 0.05 was set for statistical significance. RESULTS: Overall, upper tract recurrence occurred in 23 of 127 (18.1%) patients. 35 of 127 (34%) patients developed MBT. Prescence of MBT vs absence of MBT was predictive of overall UTUC recurrence with incidence of 12 of 35 (34%) vs 11 of 92 (12%) (p=0.0035). Presence of MBT vs absence of MBT was also predictive of solely contralateral UTUC recurrence with incidence of 3 of 26 (11.5%) vs 0 of 81 (0%) (p=0.0019). CONCLUSIONS: Identification of metachronous bladder tumors during surveillance for UTUC is predictive of upper tract recurrence. This is applicable to patients who have bilateral renal units being treated with endoscopic management as well as in patients with a solitary kidney after nephroureterectomy. Physicians should be aware of the increased rate of recurrence in these patients when performing surveillance. Source of Funding: Mayo Clinic Florida © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e679 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Christian Ericson More articles by this author Anthony Compton More articles by this author Bryce Baird More articles by this author Raymond Pak More articles by this author Expand All Advertisement PDF DownloadLoading ...

MP40-08 NOVEL ENDOSCOPIC MANAGEMENT FOR LOCALIZED UPPER URINARY TRACT CARCINOMA USING A PHOTODYNAMIC DIAGNOSIS-GUIDED DUAL LASER ABLATION TECHNIQUE: 3-YEAR FOLLOW-UP RESULTS

You have accessJournal of UrologyCME1 May 2022MP40-08 NOVEL ENDOSCOPIC MANAGEMENT FOR LOCALIZED UPPER URINARY TRACT CARCINOMA USING A PHOTODYNAMIC DIAGNOSIS-GUIDED DUAL LASER ABLATION TECHNIQUE: 3-YEAR FOLLOW-UP RESULTS Takashi Yoshida, Tadashi Matsuda, Chisato Ohe, and Hidefumi Kinoshita Takashi YoshidaTakashi Yoshida More articles by this author , Tadashi MatsudaTadashi Matsuda More articles by this author , Chisato OheChisato Ohe More articles by this author , and Hidefumi KinoshitaHidefumi Kinoshita More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002600.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Radical nephroureterectomy (RNU) is the gold standard treatment for localized upper tract urothelial carcinoma (UTUC); however, ureteroscopic surgery (URS) has become a more common treatment option for low-risk cases (<2 cm, low grade, and low stage) or imperative cases (solitary kidneys, bilateral tumors, or impaired renal function). Our group has demonstrated URS using the photodynamic diagnosis-guided dual laser ablation (PDD-DLA) technique (Yoshida T et al. Eur Urol Open Sci. 2021). In this analysis, we evaluated its long-term efficacy in patients with UTUC undergoing PDD-DLA. This study aimed to compare the efficacy of PDD-DLA versus the conventional holmium laser ablation (HLA) to evaluate oncological outcomes. METHODS: The study included ten consecutive patients with UTUC who underwent PDD-DLA between 2017 and 2019, and 16 consecutive patients who underwent HLA between 2006 and 2016 as a historical control group. The primary endpoint for the study was disease progression (defined as a relapsing tumor that could not be continued with a conservative approach and/or distant metastases). Secondary endpoints were to evaluate UTUC recurrence-free survival (RFS) and intravesical recurrence-free survival (IVRFS). The Kaplan-Meier method with log-rank test was used for survival analysis. RESULTS: The baseline characteristics were well balanced between the PDD-DLA and HLA groups in terms of tumor size, tumor grade, and multifocality. The disease progression-free rate was significantly higher among patients treated with PDD-DLA than in the HLA group (median survival: not reached vs. 33.9 months; p=0.025). The UTUC-RFS rate was not significantly different between the two groups (median survival: 21.0 vs. 8.8 months; p=0.139), The IVRFS rate was better in the PDD-DLA group when compared with those treated with HLA (median survival: not reached vs. 22.9 months; p=0.029). CONCLUSIONS: PDD-DLA was beneficial as a kidney-sparing surgery for UTUC with a 3-year follow-up. Furthermore, PDD-DLA prevented IVR when compared with the conventional method. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e676 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Takashi Yoshida More articles by this author Tadashi Matsuda More articles by this author Chisato Ohe More articles by this author Hidefumi Kinoshita More articles by this author Expand All Advertisement PDF DownloadLoading ...

A prospective, single-arm trial of fluorescent ureteroscopy-assisted thulium-holmium:YAG dual laser ablation for upper urinary tract cancer: Study protocol of the FLUAM trial

BackgroundLatest guidelines recommend kidney-sparing management as the primary treatment option for selected patients with upper urinary tract urothelial carcinoma (UTUC). One of the biggest issues of ureteroscopic laser ablation (ULA) is a high rate of surgical site recurrence, which is largely attributed to residual lesions at the initial ULA. Another clinical issue is a significant lack of non-invasive reliable detection tools of urinary recurrent tumors in this treatment setting. MethodsThe FLUAM trial is a prospective, single-center, single-arm pilot trial to investigate the efficacy of 5-aminolevulinic acid-mediated photodynamic diagnosis (ALA-PDD)-assisted ULA for localized UTUC and the usefulness of the UroVysion® assay (multiprobe fluorescence in situ hybridization) as a monitoring test after the kidney-sparing treatment. After the screening and registration, a total of 20 patients with localized UTUC will undergo the initial ALA-PDD-assisted ULA followed by the second look ALA-PDD-assisted ureteroscopic examination. The primary endpoint is progression-free survival. Secondary endpoints include patient reported outcomes, diagnostic accuracy of UroVysion assay to detect tumor recurrence, adverse events, and safety of the intervention. ConclusionThe goal of this trial is to determine the potential benefit of ALA-PDD assistance in patients who undergo the ULA. The evidence of this novel technique is still limited. The results are expected to change the standard of care and lead to better management of localized UTUC. Trial registrationThis clinical trial was prospectively registered with the Japan Registry of Clinical Trials on 23 June 2021. The reference number is jRCTs051210042, nara0023 (Certified Review Board of Nara Medical University).

1140 - Efficacy of endoscopic management with photodynamic diagnosis-guided dual laser ablation for upper urinary tract carcinoma: Initial experience

1140 - Efficacy of endoscopic management with photodynamic diagnosis-guided dual laser ablation for upper urinary tract carcinoma: Initial experience

Characterization of neutral boron-silicon clusters using infrared spectroscopy: The case of Si6B

Nano-size clusters are of great interest for understanding of fundamental properties and processes relevant for applied materials science such as heterogeneous catalysis. In this study, we present a newly developed dual-target dual-laser ablation source, suitable for the production of binary clusters and their spectroscopic characterization. With the current design, an almost arbitrary mixing ratio can be achieved by altering different parameters such as the laser fluences. Boron and silicon targets are chosen for cluster production, illustrating the possibility to control the outcome ranging from pure boron over mixed SinBm to pure silicon clusters. As a test system, Si6B clusters are characterized by means of infrared-ultraviolet two-color ionization (IR-UV2CI) spectroscopy, combined with quantum chemical simulations. The most stable structure of Si6B (Cs, 2A′) predicted in our previous work is confirmed by the present experiment. Doping of Si7 with a single B atom has a drastic impact on the geometric, vibrational, and electronic properties.

Rapid cell mode switching and dual laser ablation inductively coupled plasma mass spectrometry for elemental bioimaging.

Two different approaches to improve the limits of detection (LODs) in elemental bioimaging have been developed. They both consider the fact that for the widely applied quadrupole-based instruments, metals in the mass range <100 u are analyzed with the best figures of merit in the kinetic energy discrimination (KED) mode; much better LODs are achieved for some metalloids and nonmetals by the introduction of more reactive gases, e.g., oxygen, into the collision/reaction cell (CRC). While the first approach simultaneously utilizes two inductively coupled plasma mass spectrometry (ICP-MS) detectors hyphenated to one laser ablation (LA) system, the second is based on a single ICP-MS instrument with fast cell mode switching (CMS) of the CRC between individual line scans. Both methods were evaluated concerning their respective improvements by the analysis of rat brain samples. The utilization of two detectors showed improved LODs compared with conventional KED-only analysis in dependency on the gas flow splitting ratio, e.g., for sulfur by about 3.5 orders of magnitude. CMS provided even better results with a further improvement by a factor of 1.6. As a CRC with a small inner volume was used, fast cell gas switches at the end of every line prevented issues related to the reproducibility of the laser ablation stage for the CMS approach. Linear interpolation was found to be a valuable tool without affecting the spatial resolution of the images. In addition, a software macro is presented, which facilitates data evaluation.

Enhanced magnetism and ferroelectricity in epitaxial Pb(Zr0.52Ti0.48)O3/CoFe2O4/La0.7Sr0.3MnO3 multiferroic heterostructures grown using dual-laser ablation technique

PbZr0.52Ti0.48O3/CoFe2O4/La0.7Sr0.3MnO3 (PZT/CFO/LSMO) and PZT/LSMO heterostructures were grown on single-crystal MgO (100) substrates using the dual-laser ablation technique. X-ray diffraction confirmed the epitaxial relationship between the layers in the heterostructures. Magnetization measurements showed in-plane uniaxial magnetic anisotropy in PZT/CFO/LSMO with enhanced saturation magnetization of 288 emu/cm3 as compared to 244 emu/cm3 for PZT/LSMO. With the introduction of the hard magnetic CFO, the low coercivity of PZT/LSMO increased from 0.1 kOe to 1.4 kOe. Polarization measurements showed well-saturated square hysteresis loops for PZT/CFO/LSMO with enhanced remanent polarization (Pr) values of 69 μC/cm2 at a coercive field (Ec) of 88 kV/cm as compared to Pr = 51 μC/cm2 at Ec = 39 kV/cm for PZT/LSMO. The improved hard ferromagnetic and ferroelectric properties in PZT/CFO/LSMO as compared to PZT/LSMO make it desirable for multiferroic device applications.

Publisher’s Note: “Role of dual-laser ablation in controlling the Pb depletion in epitaxial growth of Pb(Zr0.52Ti0.48)O3 thin films with enhanced surface quality and ferroelectric properties” [J. Appl. Phys. 111, 064102 (2012)

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Role of dual-laser ablation in controlling the Pb depletion in epitaxial growth of Pb(Zr0.52Ti0.48)O3 thin films with enhanced surface quality and ferroelectric properties

Pb depletion in Pb(Zr0.52Ti0.48)O3 (PZT) thin films has remained as a major setback in the growth of defect-free PZT thin films by pulsed laser ablation techniques. At low excimer (KrF) laser fluences, the high volatility of Pb in PZT leads to non-congruent target ablation and, consequently, non-stoichiometric films, whereas, at high laser fluences, the inherent ejection of molten droplets from the target leads to particulate laden films, which is undesirable in heterostructure growth. To overcome these issues, a dual-laser ablation (PLDDL) process that combines an excimer (KrF) laser and CO2 laser pulses was used to grow epitaxial PZT films on SrTiO3 (100) and MgO (100) substrates. Intensified-charge-coupled-detector (ICCD) images and optical emission spectroscopy of the laser-ablated plumes in PLDDL revealed a broader angular expansion and enhanced excitation of the ablated species as compared to those for single-laser ablation (PLDSL). This led to the growth of particulate-free PZT films with higher Pb content, better crystallinity, and lower surface roughness as compared to those deposited using PLDSL. For FE measurements, PZT capacitors were fabricated in situ using the latticed-matched metallic oxide, La0.7Sr0.3MnO3, as the top and bottom electrodes. PZT films deposited using PLDDL exhibited enhanced polarization for all driving voltages as compared to those deposited using PLDSL. A highest remanent polarization (Pr) of ∼91 μC/cm2 and low coercive field of ∼40 kV/cm was recorded at 9 V driving voltage. Fatigue characterization revealed that PZT films deposited using PLDDL showed unchanging polarization, even after 109 switching cycles.

Fourier transform infrared isotopic study of ZnC3: Identification of the ν1(a′) mode

An isomer of ZnC(3) with bent structure in its (1)A(') electronic state has been detected in the products from the dual laser ablation of carbon and zinc rods that were trapped in solid Ar at ~12 K. Measurements of (13)C isotopic shifts have enabled the identification of the ν(1)(a(')) asymmetric carbon stretching fundamental at 1858.9 cm(-1). The experimental results are in good agreement with the predictions of DFT-B3LYP/6-311G(d) calculations that indicate a singlet bent isomer ground state structure with triplet linear and singlet cyclic isomers lying slightly higher in energy. This is the first optical detection of any isomer of ZnC(3).

Fourier transform infrared isotopic study of linear MnC3: Identification of the ν1(σ) fundamental

Linear MnC(3) has been detected in the products from the dual laser ablation of carbon and manganese rods trapped in solid Ar at ∼12 K. The ν(1)(σ) vibrational fundamental, an asymmetric carbon stretching mode, has been identified at 1846.9 cm(-1). Fourier transform infrared measurements of (13)C isotopic shift are in good agreement with the predictions of density functional theory calculations using the mPW1PW91 functional with 6-311+G(3df) basis set. This is the first optical detection of the linear isomer of MnC(3) for which previous photoelectron spectroscopy studies have reported evidence of a cyclic isomer.

Infrared observation of linear GeC3 trapped in solid Ar

Linear GeC(3) has been synthesized and its vibrational spectrum observed for the first time. The cluster was detected by Fourier transform infrared spectroscopy when the products from the dual laser ablation of either a pair of carbon and germanium rods or a single, sintered germanium-carbon rod were trapped in solid Ar at approximately 10 K. Comparison of (13)C isotopic shift measurements with the predictions of density functional theory calculations at the B3LYP/cc-pVDZ level has resulted in the identification of the nu(1)(sigma) and nu(2)(sigma) modes of linear GeC(3) at 1903.9 and 1279.6 cm(-1), respectively. For the related group IV clusters, this result is in contrast to SiC(3) for which two cyclic isomers have been observed but similar to C(4) for which only the linear isomer has been observed spectroscopically.

Investigation of the Pb Depletion in Single and Dual Pulsed Laser Deposited Epitaxial PZT Thin Films and Their Structural Characterization

AbstractWe have investigated the Pb depletion in laser ablated PZT (PbZr0.52Ti0.48O3) films through a systematic study of PZT target-laser interactions for both single laser and dual-laser ablation methods. The study includes films deposited from a stoichiometric and an excess PbO PZT targets. The films were deposited on single crystal SrTiO3[100] substrates at 550˚C with a background oxygen pressure of 500 mT. Single laser deposited films at a laser fluence of 5J/cm2 produced the highest Pb content while dual-laser ablated films where an excimer and a CO2 pulsed lasers were synchronized for ablation produced high Pb content for an excimer laser fluence of less than 2J/cm2. This enabled the growth of particulate-free PZT films with high Pb content. ICCD imaging of the plasma plumes showed variations in the expansion profiles at different laser fluencies that correlated well with the Pb content observed in the deposited films.

FTIR Identification of the ν4(σu) and ν6(πu) Modes of Linear GeC3Ge Trapped in Solid Ar

GeC 3Ge was previously (1) produced by the dual laser ablation of germanium and carbon rods, and the nu 3(sigma u) carbon-carbon stretching fundamental was assigned at 1920.7 cm (-1). This paper presents results from new experiments that have enhanced the production of the molecule via laser ablation of a single sintered germanium-carbon rod, thus enabling the identification of two additional infrared active vibrational fundamentals. Ge participates strongly in one of these, the nu 4(sigma u) mode, and the corresponding Ge isotopic shifts reported here are the first for a germanium-carbon species. GeC 3Ge was produced by trapping the products from the laser evaporation of the Ge-C rod, in solid Ar at approximately 10 K, and recording the FTIR (Fourier transform infrared) spectra. Comparison of (70,72,73,74,76)Ge and (13)C isotopic shift measurements with the predictions of density functional theory calculations (DFT) at the B3LYP/cc-pVDZ level confirms the identification of the nu 4(sigma u) stretching fundamental at 735.3 cm (-1) and the nu 6(pi u) bending fundamental at 580.1 cm (-1) for linear GeC 3Ge.

Borosilicate glass for photonics applications

In this paper, we present the use of three different processing techniques which can be used to manufacture low cost optical waveguides and fibers using commercially available borosilicate glass. The techniques used are rod and tube stacking for photonic crystal fiber fabrication, dual laser ablation processing for planar waveguides, and thermal poling, which could potentially be used for refractive index engineering of planar optical waveguides.

Fourier transform infrared observation of the ν1(σ) mode of linear CoC3 trapped in solid Ar

Fourier transform infrared (FTIR) and density functional theory (DFT) isotopic studies on cobalt-carbon species have resulted in the detection of linear CoC3. Dual laser ablation of carbon and cobalt rods, followed by trapping the products in solid Ar at approximately 10 K, produced the CoC3 chain. FTIR measurements of 13C isotopic shifts are in good agreement with the predictions of DFT calculations using the B3LYP and BPW91 functionals and the 6-311+G(3df) basis set, confirming the assignment of the nu1(sigma) fundamental of linear CoC3 at 1918.2 cm(-1).

Time of flight of dual-laser ablation carbon plasmas by optical emission spectroscopy

Plasma emission induced by dual pulse laser ablation on graphite target was analyzed by time resolved optical spectroscopy. Experiments were carried out at a pressure of 10-5 Torr using two Nd : YAG lasers emitting at 1064 and 532 nm synchronized at up to 100 μs delay. Up to fivefold intensification of the C II emission lines was observed, when the delay between lasers was set in the 500–1000 ns range. From the time of flight measurements, the ion energy distribution could be controlled by changing the pulse delay between lasers.

Evidence for the physical basis and universality of the elimination of particulates using dual-laser ablation. II. Dynamic time-resolved target reflectivity of metals and film growth of Zn

We have presented, in Part I of this series of two articles, the applicability of dynamic melt studies of the surface of a target under pulsed CO2 laser radiation to determine the onset of melt in these targets. Determination of this time and the accurate synchronization of an excimer (KrF) laser to coincide with the onset of melt on the target surface was shown to lead to particulate-free film deposition for Y2O3 and ZnO films. A key feature of the pump–probe reflectivity studies was the dynamic enhancement of the reflected probe signal, indicating the onset of melt. Some metallic targets, depending on the diameter of the precursor powder globules, such as the zinc target used in this study, do not yield such observable enhancements. In this article (Part II) we present the determination of the time for ablation of a variety of metallic targets under pulsed CO2 laser radiation, by monitoring the dynamic target reflectivity. The melt time is either directly determined or, in the absence of observable melt, estimated based on a simple thermal model for the absorption of the laser radiation by the target. Correlation of the calculated melt times with the morphological quality of particulate-free film growth of Zn is demonstrated. The effect of variable CO2 laser fluence on the deposited films is also demonstrated. The universality of applicability of the target reflectivity studies to a wide range of dissimilar materials, as well as the physical basis for the removal of particulates in dual-laser ablation is established.