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oe1(光电查) - 科学论文

199 条数据
?? 中文(中国)
  • Cytotoxic Effects of Titanium Dioxide Nanaoparticles Synthesized by Laser Technique on Peripheral Blood Lymphocytes and Hep-2 Cell Line

    摘要: Objective: This study assay the toxic effects of titani-um dioxide nanoparticles (TiO2NPs) on peripheral blood lymphocytes and Hep-2 cell by measuring Mitotic Index (MI), Blastogenic Index (BI), Total Chromosomal Aberration (TCA) and growth rate of cancer cells. Methods: TiO2NPs were synthesized using laser tech-nique by ablation of titanium target immersed in dis-tilled de-ionized water (DDW) using Q-switched pulsed Nd:YAG laser with repetition rate of 1 Hz, wavelength of 1064 nm, 300 pulses and energy of 400 mJ. Chro-mosomal analyses were carried out at different con-centrations of synthesized TiO2 NPs (0.0, 45, 90, and 180) μg/mL. Results: X-ray diffraction (XRD) exhibited anatase phase of prepared TiO2NPs and showed that the crys-talline structures of TiO2NPs is tetragonal. Absorption spectrum of TiO2 NPs was at ultraviolet-region 215 nm due to Surface Plasmon Resonance (SPR), and the par-ticles size distribution of the prepared TiO2NPs ranged from 40 to 110 nm. Finding showed that both MI and BI suffered from high reduction while TCA suffered from significant elevation represented by Chromatid Breaks (CB), Micronuclei (MN) and Ring Chromosome (RC). The highest proportion of (TCA) has been observed in 180 μg/mL of TiO2NPs, (significant at p≤0.05). while the toxic effects of prepared TiO2NPs on Hep-2 cell line represent decline in growth rate with an increase in concentration of TiO2NPs with malformation in the cell structure and shape and placement of the nucleus. Conclusion: The ablation via Q-switched Nd: YAG laser has adequacy to prepare TiO2NPs with 215 nm absorption spectrum, nearly spherical particles and suitable particle size (40-110 nm). In vitro assay showed that prepared TiO2 NPs have significant cytotoxic effects on peripheral blood lymphocyte and Hep-2 cell line by reduction in both Mitotic index (MI) and blasto-genic index (BI) and growth rate of cancer cells.

    关键词: Titanium Dioxide Nanaoparticles,Hep-2 cell line,Mitotic Index,Q-switched pulsed Nd:YAG laser,Chromosomal Aberration,Blastogenic Index

    更新于2025-09-12 10:27:22

  • Successful Treatment of Cosmetic Eyebrow Tattoos in Fitzpatrick III‐IV With Picosecond (1,064, 532‐nm) Neodymium‐Doped Yttrium Aluminum Garnet Laser With a Perfluorodecalin‐Infused Patch: A Pilot Study

    摘要: Background and Objectives: Nanosecond Q‐switched lasers have been used for the removal of traditional and cosmetic tattoos. Picosecond lasers utilize pulse durations of 10?12 and provide more efficient clearance of tattoos. Safe and effective removal of tattoos is especially important in cosmetically sensitive areas such as the face. We report four patients with skin types (III–IV) who have had successful removal of eyebrow tattoos with the picosecond (1,064‐, 532‐nm) laser using a perfluorodecalin‐infused patch (PFD). Study Design/Materials and Methods: Patients with eyebrow tattoos underwent treatment with dual‐wavelength picosecond Nd:YAG laser at 1,064‐nm with a 3 mm spot size and fluence of 4–4.6 J/cm2. The 532‐nm wavelength was also used during treatment #1 (patient 2 only) with a 4 mm spot size and fluence of 0.5 J/cm2. Patient 1 had a total of three treatments (6–8 weeks apart). The remaining patients, each had only one treatment. Patients were photographed prior to treatment and subsequently at each follow‐up. Results: Immediately following each laser treatment, only mild and transient localized erythema and edema was observed. Some epidermal crusting was noted for 3–5 days following each treatment. Eyebrow hair growth was not affected and no adverse events were reported. There was 75% clearance in patient 1 after three treatments over a period of 2.5 months, 75% clearance in patient 2 after one treatment, 90% clearance in patient 3 after one treatment, and 100% clearance in patient 4 after one treatment. Conclusions: The 532‐ and 1,064‐nm wavelength of the picosecond Nd:YAG laser was safely used to clear brown and black ink eyebrow tattoos in four patients, three of whom were skin type IV, and one of whom underwent eyebrow tattoo via microblading, a novel and popular technique for cosmetic tattoos. The use of picosecond laser provides several treatment advantages to Q‐switched laser when treating eyebrow tattoos. In our experience, it required less number of treatments and lower fluences. This, along with use of the perfluorodecalin‐infused patch resulted in excellent outcomes for our patients with no significant side effects.

    关键词: microblading,Nd:YAG,permanent makeup,picosecond,cosmetic tattoos,eyebrow tattoo,neodymium‐doped yttrium aluminum garnet

    更新于2025-09-12 10:27:22

  • Evolution of surface morphology of Er:YAG laser-machined human bone

    摘要: The extensive research on the laser machining of the bone has been, so far, restricted to drilling and cutting that is one- and two-dimensional machining, respectively. In addition, the surface morphology of the laser machined region has rarely been explored in detail. In view of this, the current work employed three-dimensional laser machining of human bone and reports the distinct surface morphology produced within a laser machined region of human bone. Three-dimensional laser machining was carried out using multiple partially overlapped pulses and laser tracks with a separation of 0.3 mm between the centers of consecutive laser tracks to remove a bulk volume of the bone. In this study, a diode-pumped pulse Er:YAG laser (λ = 2940 nm) was employed with continuously sprayed chilled water at the irradiation site. The resulting surface morphology evolved within the laser-machined region of the bone was evaluated using scanning electron microscopy, energy dispersive spectroscopy, and X-ray micro-computed tomography. The distinct surface morphology involved cellular/channeled scaffold structure characterized by interconnected pores surrounded by solid ridges, produced within a laser machined region of human structural bone. Underlying physical phenomena responsible for evolution of such morphology have been proposed and explained with the help of a thermokinetic model.

    关键词: Laser osteotomy,Laser machining,Surface morphology,Er:YAG laser,Scaffold

    更新于2025-09-12 10:27:22

  • Mild accidental macular injury induced by picosecond Nd:YAG laser

    摘要: Accidental laser-associated ophthalmic complications are rare disorders which were first described in 1965 by Rathkey as a ‘laser burn’ of the macula. Most reported ophthalmic complications have been induced by nanosecond neodymium-doped yttrium aluminium garnet (Nd:YAG) laser. Several studies have reported that most nanosecond Nd:YAG laser-associated ophthalmic complications are choroidal neovascularisation, macular hole, and vitreous haemorrhage. These complications also have been reported as poor prognosis of visual function. Few reports appear to have described picosecond Nd:YAG laser-associated ophthalmic complications. In this report, a case of mild ophthalmic complications of subretinal and choroidal haemorrhage due to accidental picosecond Nd:YAG laser irradiation is described.

    关键词: optical coherence tomography,angiography,picosecond Nd:YAG laser,ophthalmic complications

    更新于2025-09-12 10:27:22

  • Nd <sup>3+</sup> :YAG laser based on the <sup>4</sup> F <sub/>3/2</sub> → <sup>4</sup> I <sub/>13/2</sub> secondary transition with a phase-conjugate electro-optically Q-switched open multiloop cavity

    摘要: Lasing on the 4F3/2 → 4I13/2 secondary transition (λ = 1.34 μm) in a Nd3+ : YAG laser with phase conjugation by four-wave mixing directly in the active laser medium was experimentally studied in the regime of electro-optic Q-switching of an open multiloop cavity. The use of an electro-optic Q-switch with a controllable delay of its opening made it possible to increase the amplitude and temporal stabilities of the output laser parameters. The maximum laser pulse energy was 100 mJ at a pulse duration of 120 ns. The phase-conjugate radiation divergence was 0.8 mrad at beam quality Mx2 = My2 = 1.3. Nonlinear optical conversion of 1.34 μm laser radiation to visible radiation was achieved experimentally. Second and third harmonic generation at wavelengths of 0.67 and 0.446 μm with conversion efficiencies of 25 % and 8 %, respectively, was demonstrated.

    关键词: phase conjugation,secondary transition,stability of laser parameters,Nd3+ : YAG laser,electro-optic Q-switching

    更新于2025-09-12 10:27:22

  • Novel single-frequency Nd:YAG ring laser by reducing the depolarization loss

    摘要: A principle study on reducing the depolarization loss in a single-frequency Nd:YAG ring laser by a novel ring resonator configuration is reported. In the resonator, one cavity mirror with 99.5% reflectivity at 1064 nm for 45-degree incident s-polarized light and about 75% transmissivity for 45-degree incident p-polarized light was employed. Besides, the transmissivity for the 45-degree incident p-polarized and s-polarized light for the output-couple mirror were 32% and 3.5%, respectively. The cavity mirror and the output-couple mirror were utilized as the polarizer to enforce the s-polarized beam unidirectionally operating in the resonator. 2.1 W single-frequency output at 1064 nm with elliptical polarization was obtained from this ring resonator. Compare with the existent Nd:YAG ring resonator, this novel resonator has a potential advantage in reducing depolarization loss and increasing the efficiency.

    关键词: Nd:YAG,Depolarization loss,Ring resonator,Single-frequency

    更新于2025-09-12 10:27:22

  • Clinical evaluation of multiple peri-implant bony defect management by Er:YAG laser-assisted bone regenerative therapy

    摘要: Conventional mechanical debridement is the main procedure for treating plaque-induced peri-implantitis, such as using plastic/metallic curettes, sand blasting machines, polishing by rubber cup/pumice powder, ultrasonic scalers, and titanium brushes. However, it is difficult to completely remove bacterial plaque with these instruments, especially in the micro-threads area. Recently, use of Er:YAG laser in dental field has increased for periodontal and peri-implantitis therapy, because Er:YAG laser is able to effectively ablate soft and hard tissues as well as calculus, and it can effectively debride the titanium surface with minimal thermal damage under suitable energy output. Meanwhile, the blood clot forming in the superficial areas of grafted bone by Er:YAG laser irradiation without water spray is useful for bone regenerative procedure, which is so called the Er:YAG laser-assisted bone regenerative therapy (Er-LBRT) developed by Taniguchi et al. This case report demonstrated a perspective option for implant surface debridement and simultaneously bone regeneration by Er-LBRT technique without usage of membrane coverage.

    关键词: implant surface debridement,bone regenerative therapy,peri-implantitis,Er:YAG laser

    更新于2025-09-12 10:27:22

  • Multi‐Factors Associated With Efficacy and Adverse Events of Fractional Erbium:YAG Laser‐Assisted Delivery of Topical Betamethasone for Stable Vitiligo: A Retrospective Analysis

    摘要: Background and Objectives: Although topical corticosteroids are still the first‐line option for vitiligo, its efficacy is still unsatisfactory for stable vitiligo. A few studies have focused on laser‐assisted drug delivery (LADD) but were limited by their sample deficiency and analyses of the influencing factors. To determine the efficacy, adverse events, and their influencing factors of fractional erbium: yttrium‐aluminum‐garnet (Er:YAG) laser‐assisted topical delivery of corticosteroids in stable vitiligo. Study Design/Materials and Methods: We retrospectively reviewed 1,026 lesions in 684 patients with stable vitiligo who underwent treatment with fractional Er:YAG laser‐assisted delivery of topical compound betamethasone solution between January 2014 and December 2017. Multi‐factors associated with different outcomes were analyzed by logistic regression in this study. Results: A total of 413 of 1,026 lesions (40.3%) were effective 12 months after the first treatment. Age (<14 years old), disease duration (<1 year), lesion location (on face and neck), hairy lesions, and drug concentration were independent factors associated with effective repigmentation. A common adverse event was hyperpigmentation (14.4%), which was highly correlated with 22% density. Conclusions: Fractional Er:YAG laser‐assisted delivery of topical compound betamethasone is a good option for the management of vitiligo. The treatment may be suggested in these situations: younger patients, shorter disease duration, and lesions on the face and neck with hair. The appearance of white hair in the lesion area does not affect our confidence in vitiligo treatment. Density >22% may cause hyperpigmentation, but it does not significantly contribute to the efficacy.

    关键词: betamethasone,laser‐assisted drug delivery,fractional Er:YAG laser,vitiligo,repigmentation

    更新于2025-09-12 10:27:22

  • Erbium:YAG laser treatment of female stress urinary incontinence: midterm data

    摘要: Introduction and hypothesis Stress urinary incontinence (SUI) is treated using intravaginal laser therapy. We wanted to find out how incontinence severity at baseline and the number of laser interventions affect success rate, and whether the effect of laser therapy was obvious 6 months and 2 years after the last laser intervention. Methods Fifty-nine women, 32 with SUI I, 16 with SUI II, and 11 with SUI III were treated using an erbium-doped yttrium aluminium garnet (Er:YAG) laser following the IncontiLase? protocol. Therapy included five laser sessions with a 1-month interval between sessions. Objective (1-h pad test) and subjective data (International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form [ICIQ-UI SF], Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire [PISQ-12]) were assessed at baseline, after two and four laser sessions and 6 months and 2 years after the fifth laser session. Results Objective cure/improve rates for mild SUI I were 69%, 78%, 91%, and 78% after two, four, and five laser sessions at the 6-month and 2-year follow-ups. Subjective cure rates (ICIQ-UI SF) were 53%, 69%, 72%, and 66%, and sexual function (PISQ-12) also improved. For SUI II, objective cure/improve rates were 31%, 63%, 69%, and 50%. Subjective cure rate was 13% at the 2-year follow-up. For SUI III, only one patient had an objective improvement after two and four laser sessions. Conclusions Intravaginal laser therapy led to cure/improvement for SUI I and SUI II, but not for severe SUI III. Outcome was better after four to five laser sessions than after two laser sessions. Follow-up data 6 months and 2 years after laser intervention showed sustainability of the treatment.

    关键词: ICIQ-UI SF,1-h pad test,Stress urinary incontinence,Intravaginal laser therapy,Erbium:YAG laser,Non-ablative SMOOTH mode

    更新于2025-09-12 10:27:22

  • Femtosecond laser system based on thin rod Yb : YAG active elements with an output power of 110 W

    摘要: A three-stage laser amplification system based on thin Yb : YAG rods with diode laser pumping is developed and fabricated. In this system, the average power of a continuous train of femtosecond pulses from a Yb : KGW master oscillator with a pulse repetition rate of 80 MHz and initial pulse duration of 128 fs was raised by a factor of 100 to above 100 W. Preliminarily chirped laser pulses provided compensation of dispersion in optical elements of the system and obtaining 580-fs output pulses. The longer duration of output pulses relates to spectrum narrowing in the amplifiers.

    关键词: diode-pumped laser amplifier on Yb :YAG,high average radiation power,femtosecond pulses

    更新于2025-09-12 10:27:22