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Femtosecond Laser Surgery in Ophthalmology
摘要： This comprehensive, well-organized text encompasses the numerous applications of femtosecond lasers to anterior segment surgery. From the use of laser-assisted in situ keratomileusis flap creation, cataract surgery, and even femtosecond-assisted keratopigmentation, this text thoroughly reviews all aspects of technology, leaving no application uncovered, highlighting the great versatility and potential of this technology. Each of the chapters is written by 1 to 3 experienced ophthalmic surgeons, and the text is well edited to assure completeness and prevent redundancy.
关键词： anterior segment surgery,femtosecond laser,laser-assisted in situ keratomileusis,ophthalmology,cataract surgery
更新于2025-09-12 10:27:22
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Femtosecond Laser-Assisted In Situ Keratomileusis Treatment of Residual Refractive Error following Femtosecond Laser-Enabled Keratoplasty
摘要： Purpose. To evaluate the safety and effectiveness of femtosecond laser-assisted in situ keratomileusis (LASIK) in the treatment of residual myopia and astigmatism following femtosecond laser-enabled keratoplasty (FLEK). Design. Retrospective case review. Methods. Chart review of all patients with prior FLEK who subsequently underwent femto-LASIK surgery after full suture removal was performed at the Gavin Herbert Eye Institute at the University of California, Irvine. A total of 14 eyes in 13 patients met this criterion, and their comprehensive examinations performed at standard intervals were reviewed. Main outcome measures include uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) expressed as the logarithm of the minimum angle of resolution (logMAR), manifest refractive astigmatism, and spherical equivalent. Results. From the preoperative visit to the 3 month visit, all 14 eyes significantly improved in UDVA (logMAR, 0.93 ± 0.23 to 0.44 ± 0.32, P = 0.002) with no loss of CDVA (logMAR, 0.26 ± 0.19 to 0.18 ± 0.23, P = 0.50). All 14 eyes showed significant improvement in manifest refractive astigmatism (4.71 ± 1.77 to 2.18 ± 1.45 diopters (D), P = 0.003) and spherical equivalent (? 2.57 ± 2.45 to ? 0.48 ± 0.83 D, P = 0.0007). There were no flap or graft complications as a result of femto-LASIK. Conclusions. Our findings suggest that femto-LASIK on eyes with prior FLEK is safe and effective in improving visual acuity and reducing residual astigmatism.
关键词： femtosecond laser-enabled keratoplasty,LASIK,femtosecond laser-assisted in situ keratomileusis,residual myopia,astigmatism,FLEK
更新于2025-09-12 10:27:22
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Long-term assessment of visual and refractive outcomes of laser in situ keratomileusis for hyperopia using the AMARIS? 750S Excimer laser
摘要： Purpose. — To evaluate the long-term efficacy and safety of hyperopic laser in situ keratomileusis (LASIK) using the AMARIS? 750S (Schwind, Eye-tech-solutions, GmbH) excimer laser. Methods. — The medical records of one hundred eleven eyes of 62 patients who underwent LASIK for hyperopia using the AMARIS? 750S excimer laser were reviewed retrospectively. Patients were divided into three groups based on preoperative spherical equivalent (SE) refraction: low hyperopia (less than +2.50 diopters [D]), moderate hyperopia (+2.75D to +4.00D), and high hyperopia (over +4.00D). Uncorrected and best corrected visual acuity (BCVA), long-term stability of refraction, and complications were evaluated. Results. — Of the entire sample, the mean preoperative SE was +3.64D ± 1.22D. The mean age was 37.4 ± 11.2 years (20—59). The mean follow-up for all eyes was 51 months. At the last visit, the mean SE was +0.85D ± 0.34D in the low hyperopia group, +1.09D ± 0.43D in the moderate hyperopia group, and +1.63D ± 0.47D in the high hyperopia group (+1.15D ± 0.49D overall). Preoperative uncorrected visual acuity (UCVA) was 0.52 ± 0.34 logMAR and increased to 0.18 ± 0.15 logMAR at 4 years follow-up (P < 0.01). There was no statistically significant difference between preoperative and postoperative BCVA. The UCVA was 0.30 logMAR or better in 100% of eyes in the low hyperopia group, 93.7% in the moderate hyperopia group, and 69.9% in the high hyperopia group (%89.2 overall). Conclusions. — LASIK is safe and effective for correcting hyperopia in the short term; however, the efficacy of the procedure is limited in the patients with high hyperopia and longer follow-up.
关键词： Hyperopic laser in situ keratomileusis,Excimer laser,LASIK,Laser in situ keratomileusis,Hyperopia
更新于2025-09-11 14:15:04
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Clinical outcomes of small incision lenticule extraction versus femtosecond laser-assisted LASIK for myopia: a Meta-analysis
摘要： ● AIM: To evaluate the possible differences in visual quality between small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK) for myopia. ● METHODS: A Meta-analysis was performed. Patients were from previously reported comparative studies treated with SMILE versus FS-LASIK. The PubMed, EMBASE, Cochrane, Web of Science and Chinese databases (i.e. WANFANG and CNKI) were searched in Nov. of 2016 using RevMan 5.1 version software. The differences in visual acuity, aberration and biomechanical effects within six months postoperatively were showed. Twenty-seven studies including 4223 eyes were included. ● RESULTS: No significant differences were observed between SMILE and FS-LASIK in terms of the proportion of eyes that lost one or more lines of corrected distance visual acuity after surgery (P=0.14), the proportion of eyes achieving an uncorrected distance visual acuity of 20/20 or better (P=0.43), the final refractive spherical equivalent (P=0.89), the refractive spherical equivalent within ±1.00 diopter of the target values (P=0.80), vertical coma (P=0.45) and horizontal coma (P=0.06). Compared with the FS-LASIK group, total higher-order aberration (P<0.001) and spherical aberration (P<0.001) were higher and the decrease in corneal hysteresis (P=0.0005) and corneal resistance factor (P=0.02) were lower in the SMILE group. ● CONCLUSION: SMILE and FS-LASIK are comparable in efficacy, safety and predictability for correcting myopia.
关键词： Meta-analysis,small incision lenticule extraction,myopia,femtosecond laser in situ keratomileusis
更新于2025-09-11 14:15:04
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Investigation of Polymer Matrix Nano‐Aluminum Composites with Pulsed Laser Heating by In‐Situ TEM
摘要： Nanocomposites of aluminum and fluoropolymers react rapidly due to highly exothermic aluminum fluorination because of the high specific surface area nanoscale particles. In-situ transmission electron microscopy (TEM) techniques are invaluable for real time monitoring of the reactions in these systems at the nanoscale. Here, we investigated the reactions in nanoscale Al (nAl) and THV (terpolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride) and nAl-LDPE (low density polyethylene) composites, heated using a pulsed laser in a TEM. Results show that reactions are initiated at about 720 K, when THV starts to decompose, and proceed with the formation and growth of a hollow aluminum fluoride (AlF3) shell. Diffraction patterns revealed that this phase is the rare η-phase AlF3. In contrast, no reactions were observed in the inert nAl-LDPE composites. The experimental and theoretical results reveal that rapid pulsed laser heating and subsequent cooling of a nanoscale sample influences the phases that can form, and can be utilized to investigate other systems.
关键词： Fluoropolymer,Nanoenergetic composites,Laser Heating,In situ TEM
更新于2025-09-11 14:15:04
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Fabrication of in-situ Ti-doped CuGaS2 thin films for intermediate band solar cell applications by sputtering with CuGaS2:Ti targets
摘要： Intermediate band solar cells (IBSCs) have great potential for improving device efficiencies, which can be fabricated by doping appropriate elements into a matrix semiconductor with a high band-gap (Eg). CuGaS2 (CGS) is an absorber with high absorption coefficient and high Eg, which is suitable to be a matrix. And some transition metals are suitable doping elements. Here, in-situ Ti-doped CGS thin films were deposited by sputtering CuGaS2:Ti targets to prepare IBSCs. The targets were fabricated by hot-pressed sintering of ball-milled Cu2S, Ga2S3, and TiS2 mixed powders. In-situ Ti-doped precursor films were prepared by sputtering with these targets. After sulfurization, grains grew up and CGS phases were gained. The Ti atoms were successfully doped into the CGS lattices. The Eg of about 2.42 eV was consistent with CGS. The current density-voltage curve of the solar cell exhibited exponential characteristics. This approach has enormous promise for the preparation of IBSCs.
关键词： In-situ doping,Intermediate band solar cells,CuGaS2:Ti targets,Sputtering,Solar energy materials
更新于2025-09-11 14:15:04
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In situ investigation of precipitation in aluminium alloys via thermal diffusivity from laser flash analysis
摘要： In this work, a commercially available laser flash analysis (LFA) device is used for in situ precipitation monitoring in aluminium alloys by following thermal diffusivity for the first time. The LFA measurement methods and data processing are adapted to allow continuous heating experiments over a wide range of heating rates (0.001–1 K s-1). Methods for LFA temperature calibration and thermal lag correction are suggested. Results of continuous heating of Al Mn0.5Mg0.5 aluminium alloy from the as-cast state are compared to in situ differential scanning calorimetry (DSC) and ex situ transmission electron microscopy. It is shown comparing in situ LFA, and DSC substantially improves the interpretation of superimposed reactions, in particular, the precipitation and dissolution of Mn-containing dispersoids and Mg–Si-containing secondary particles.
关键词： DSC,In situ LFA,Thermal diffusivity,Aluminium alloys,Precipitation,LFA thermal lag correction
更新于2025-09-11 14:15:04
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Titanium and nitrogen interactions under laser additive manufacturing conditions
摘要： To understand how to make bulk titanium parts or coatings with desired levels of titanium nitrides, this paper investigates the dynamic interactions between titanium and nitrogen under representative laser-based additive manufacturing (AM) conditions. Under a set of gas environments containing different concentrations of nitrogen, the titanium and nitrogen reaction products—formed under typical Selective Laser Melting (SLM) and Laser Engineered Net Shaping (LENS) AM scanning conditions—are examined for compositions, phases, and microstructures. In-situ synchrotron X-ray diffraction (SXRD) test is performed to reveal the high temperature reaction steps between titanium and nitrogen.
关键词： Synchrotron X-ray diffraction,in-situ phase transformation,Titanium nitridation,Laser melting
更新于2025-09-11 14:15:04
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TEM Sample Preparation of Patterned Quantum Dots
摘要： Electrochemistry and heterogeneous catalysis continue to attract enormous interest. In situ surface analysis is a dynamic research field capable of elucidating the catalytic mechanisms of reaction processes. Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) is a non-destructive technique that has been cumulatively used to probe and analyze catalytic-reaction processes, providing important spectral evidence about reaction intermediates produced on catalyst surfaces. In this perspective, we review recent electrochemical- and heterogeneous-catalysis studies using SHINERS, highlight its advantages, summarize the flaws and prospects for improving the SHINERS technique, and give insight into its future research directions.
关键词： Catalytic mechanisms,In situ surface analysis,SHINERS,Heterogeneous catalysis,Reaction intermediates,Electrochemistry,Shell-isolated nanoparticle-enhanced Raman spectroscopy
更新于2025-09-11 14:15:04
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European Microscopy Congress 2016: Proceedings || Structural transformations revealed by in-situ HRTEM observations
摘要： With the recent advance of In-Situ Transmission Electron Microscopy (In-Situ TEM), it has become a very essential technique to understand the structure-property relationships of materials. Here, we demonstrate that the formation mechanism of 1D-Si nanowires is initiated by the atom intrusion into the Si lattice at the interfaces, and the formation process is advanced by the atom intrusion into the Si lattice at the interfaces. The formation mechanism of 1D-Si nanowires is also discussed by the thermodynamic analysis. It is found that the 1D-Si nanowires are formed at the triple junction at the interfaces, and the formation process is advanced by the atom intrusion into the Si lattice at the interfaces. The formation mechanism of 1D-Si nanowires is also discussed by the thermodynamic analysis.
关键词： formation mechanism,atom intrusion,In-Situ TEM,thermodynamic analysis,1D-Si nanowires
更新于2025-09-11 14:15:04