Neodymium Yttrium Aluminum Garnet Research Articles

The use of He buffer gas for moderating the plume kinetic energy during Nd:YAG-PLD growth of EuxY2−xO3 phosphor films

We have investigated the He buffer gas process of moderating the kinetic energy of the pulsed laser deposition (PLD) plume during EuxY2−xO3 phosphor film growth. When using a neodymium yttrium aluminum garnet laser for PLD thin film growth, the kinetic energy of the ablation plumes can be high enough to cause the formation of point defects in the film. The buffer gas pressure is an important process parameter in PLD film growth. We find that the presence of the He buffer gas reduces the kinetic energy of the laser deposition plume through many low-angle collisions in the gas phase by a factor of 7 without reducing the deposition rate. This is because He is much lighter than any of the elements in the plume and it does not affect the composition of the oxide films. Consequently, the resputtering of the Y2O3 film surface by the plume was significantly suppressed in the presence of the He gas moderator, leading to a decrease of the defect density in the Y2O3 films. The improvement of the film quality was verified by a systematic analysis of time-resolved photoluminescence (PL) data for EuxY2−xO3 composition–gradient films. The PL lifetime and intensity of Eu0.2Y1.8O3, which shows the highest PL intensity, increased by 13.3% and 36.4%, respectively, when the He gas moderation process was used. The He buffer gas process is applicable to the PLD growth of the other oxide materials as well, where the reduction of the kinetic energy of the plume would bring the PLD process closer to the molecular beam epitaxy growth condition.

The Efficacy of Different Laser Applications on Dentin Sealing in Preventing Discoloration Induced by Mineral Trioxide Aggregate.

The aim of this in vitro study was to evaluate the effect of the pre-application of a dentin-bonding agent and the application of different lasers on the prevention of tooth discoloration caused by mineral trioxide aggregate (MTA) in the presence of blood. Sixty extracted human anterior teeth were selected, with root lengths standardized to 10 mm and root canals shaped using Gates-Glidden drills #3 to #5. The samples were divided into six groups (n = 10): Group 1 with no surface treatment and Groups 2 to 6 with Optibond universal adhesive and Neodymium yttrium aluminum garnet (Nd:YAG), Erbium yttrium aluminum garnet (Er:YAG), Erbium-chromium-yttrium-scandium-gallium-garnet (Er:Cr:YSGG), and diode laser applications, respectively. Root canals were filled with fresh human blood, and ProRoot MTA and a collagen barrier were then placed. Color changes were measured with a spectrophotometer at 0, 7, 30, 90, and 180 days post MTA placement. Color differences (∆E) were analyzed using a two-factor mixed-design ANOVA with the Sidak method (p = 0.05). All treatment groups exhibited discoloration above the acceptability threshold. Although all treatment approaches exhibited less color change compared to the control group (p < 0.05), there was no significant difference among them in terms of preventing color change (p > 0.05). It was determined that none of the methods could guarantee 100% prevention of discoloration caused by MTA-blood contact.

High-fluence 1064nm Q-switched Nd:YAG laser treatment for ectopic Mongolian spot

Q-switched neodymium-yttrium aluminum-garnet (Q-switched Nd:YAG) laser has been reported as an effective treatment for nevus of Ota and acquired bilateral nevus of Ota-like macules (ABNOM). Data on ectopic Mongolian spots have rarely been reported.The present study was performed to investigate the treatment efficacy of a high-fluence 1064 nm Q-switched Nd:YAG laser without tissue whitening in ectopic Mongolian spots.We included 61 patients with ectopic Mongolian spots, and 70 lesions were examined. Thirty-three lesions were treated with a high-fluence 1064 nm Q-switched Nd:YAG laser, and 38 lesions were observed without treatment. The results were assessed using a 5-quantile grading scale and melanin index using a Mexameter®.Mean follow-up duration was 14.1 ± 6.8 months for the treatment group and 17.8 ± 10.0 months for the observation group. Mean 5-quintile grading scale at final follow-up was statistically different (p < 0.001) between the two groups (treatment: 2.85 ± 1.00, observation: 0.49 ± 0.73). There was a significant difference (p < 0.001) in the Δ melanin index (initial melanin index – final melanin index) between the observation (7.1 ± 62.7) and treatment (156.7 ± 78.4) groups.High-fluence Q-switched Nd:YAG laser without tissue whitening showed good results and was well-tolerated in treating ectopic Mongolian spots.

Characteristics of copper oxide and tin oxide nanoparticles produced by using pulsed laser ablation method and their application as an antibacterial agent

The synthesis of copper oxide (CuO) and tin oxide (SnO2) nanoparticles was successfully carried out using the neodymium yttrium aluminum garnet (Nd:YAG) laser ablation method. In this study, a laser beam was focused on the surface of high-purity (99.9%) Cu and Sn plates placed into deionized water (DIW) and 0.2% carboxymethyl cellulose (CMC) liquid media, respectively, to produce colloidal CuO and SnO2 nanoparticles. CuO and SnO2 nanoparticle colloids were successfully produced with greenish and brownish colors, respectively. The colloidal nanoparticles produced in CMC media are more stable. Thus, the antibacterial test on E. coli bacteria uses CuO and SnO2 samples in CMC media. Antibacterial assessments were carried out using disc diffusion and liquid dilution methods equipped with total plate counting (TPC) techniques, with a sample variation of 26 ppm CuO, 78 ppm SnO2, and a CuO-SnO2 mixture of 5:56 ppm and 19:19 ppm samples. The results of the disc diffusion test yielded the diameter of the bacterial inhibition zone. The diameter of the inhibition zone in CuO 26 ppm, SnO2 78 ppm, and CuO-SnO2 5:56 ppm and 19:19 ppm samples, respectively, were 7.43 mm, 6.39 mm, 7.18 mm, and 6.54 mm, while the liquid dilution test equipped with TPC produced the percentage of bacterial degradation, respectively, of 98.93%, 97.60%, 98.47%, and 97.73%. The results show that all variations had the effectiveness of inhibiting and killing bacteria. From the results of various bacterial tests, colloidal CuO nanoparticles are more effective than the SnO2 nanoparticles.

Laser Treatment for Patients With Vulvodynia and Interstitial Cystitis/Bladder Pain Syndrome: A Case Series (The UNICORN-3 Study).

Introduction Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic pain disorder characterized by urgency, frequency of urination, and pelvic pain. Women with IC/BPS often experience sexual dysfunction, vulvodynia, and vaginal health issues. Combined erbium and neodymium yttrium aluminum garnet (YAG) laser treatments targeting the vagina and vulva have shown promise in improving symptoms. Our study aims to investigate the effectiveness of these combined laser treatments in women with IC/BPS and vulvodynia. Methods Women diagnosed with vulvodynia and IC/BPS underwent combined laser treatment using vaginal erbium:YAG laser (VEL) and neodymium:YAG laser (Nd:YAG). Various parameters were evaluated, including the vulvodynia test, numeric rating scale (NRS-11) for pain, interstitial cystitis symptom index and problem index (ICSI and ICPI), pelvic painand urgency/frequency symptom score (PUF), and mean urination volume/daily urination frequency in a three-day urination diary. Treatment was administered three times, with intervals of one month between each session, and follow-up evaluations were conducted at six and 12 months. All statistical analyses were designed and programmed by the AI chatbot GPT-4 (chatGPT-4). Results Fifteen female patients diagnosed with vulvodynia and IC/BPS were treated with three sessions of VEL + Nd:YAG. Significant improvements were observed in the vulvodynia test, NRS-11 scores, PUF, ICSI scores, ICPI scores, mean urination volume, and daily urination frequency at six and 12 months (p<0.01). Short-term improvements in IC/BPS pain scores correlated with improvements in the vulvodynia test (p=0.007), suggesting a synergistic effect. However, no significant correlations were found at 12 months. Conclusion Combined laser treatments targeting the vagina and vulva showed significant therapeutic effects in women with IC/BPS and vulvodynia. The addition of Nd:YAG to the VEL treatment enhanced outcomes. Short-term improvements in IC/BPS pain scores correlated with improvements in the vulvodynia test, indicating a synergistic effect. Long-term improvements in both vulvodynia and IC/BPS symptoms may occur independently.These findings highlight the importance of comprehensive approaches for treating coexisting vulvodynia and IC/BPS.

Image Contrast and Spectral Transmission in Intraocular Lenses with Nd:YAG Pits

Purpose Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered as safe and effective method in the treatment of posterior capsule opacification. Nevertheless, side effects are described. The incorrectly adjusted focus of the laser beam during the procedure can lead to so-called YAG-pits or YAG-shots. In this experimental study, we measured spectral transmission to evaluate the image contrast and analyze the impact of YAG-pits in intraocular lenses (IOL). Methods Acrylic, foldable, one-piece IOLs with 6.0 mm optic and different material properties were studied. These included: monofocal IOLs and enhanced monofocal IOLs with water content of 0.3%, 26.0%, and 4.0% and a refractive index of 1.49, 1.46, and 1.54, respectively. All measurements were done with new, unaltered IOLs and IOLs with YAG-pits. Damage was intentionally created, performing YAG-pits (n = 7) in the central zone (3.5 mm) using a photodisruption laser (2.0mJ). All laboratory measurements were repeated: These included surface topography characterization, United States Air Force (USAF) resolution test chart analysis, spectral transmittance measurements and through focus contrast measurement. Results Significant differences were found between the unaltered lenses and lenses with defects. The YAG-pits within the optic of the IOLs decreased the image contrast and spectral transmission and changed results of USAF test images at the focal position by 62%, 57% and 54%, respectively. In all IOLs a reduction of the relative intensity of total transmitted light was observed between 450 and 700 nm wavelength. Conclusion This experimental study confirmed that the IOL image performance deteriorates with YAG-pits. The total intensity of transmitted light or transmittance (without scattering) was reduced in the wavelength between 450 and 700 nm. The contrast was significantly reduced and USAF test targets showed much worse results compared to unmodified counterparts. There was no systematic difference between monofocal and enhanced monofocal lenses. Further experiments should investigate the effect of YAG-pits on diffractive IOLs.

Efficacy of Carbon Peel Laser in Acne Vulgaris in Skin of Color: A Single Center Prospective Study.

Acne vulgaris is a chronic disease of pilosebaceous units that affects approximately 80% of adult population. Despite various treatment modalities being reported, treating acne with minimal side effects is difficult. Specifically, topical carbon suspension combined with QsNdYAG laser treatment (carbon peel laser technique) has gained popularity recently for effective treatment of acne vulgaris. To study the efficacy of carbon peel laser technique in the management of acne vulgaris (Grade II-IV) in skin of color. A prospective observational study was done on 35 patients who presented with acne vulgaris Grade II-IV, who were poorly compliant to treatment with topical/systemic agents owing to side effects or failure of treatment, to meet patient's expectations. The patients were subjected to an initial topical application of carbon suspension (Cosderma Carbon gel) followed by treatment with quality switching neodymium yttrium aluminum garnet (Qs:NdYAG) laser in two modes (quasi long pulsed mode followed by Q switched mode 1064 nm). The treatment consisted of three sittings with intervals of 2 weeks. The patients were asked to avoid use of any topical/systemic medication for acne during this period. Significant reduction of erythematous and nodular acne lesions was noted after three sittings of "carbon peel laser technique". Among 35 patients, 28 (80%) showed >80% improvement and 7 (20%) showed 50%-80% improvement in skin lesions in the form of decrease in the number and size of lesions and extent of inflammation, with no patients nonresponsive to treatment. The postprocedure complications were minimal; 6 (20%) developed erythema, and 1 (3.3%) patient developed mild tolerable pain with no post inflammatory hyper/hypopigmentation. The postprocedure mean ISGA (Investigator Status Global Assessment) was 1.342 as compared with preprocedure mean ISGA of 3.657 with value of P <0.0001. Carbon peel laser technique is an effective method for the management of acne vulgaris in skin of color with minimal side effects and significant results.

The effect of Nd:YAG Laser applied in the posterior capsule opacification on retinal and choroidal structures

PurposeTo assess the effect of neodymium:yttrium–aluminum–garnet (Nd-YAG) laser procedure on the choroid and retina in patients who developed posterior capsular opacification (PCO) after cataract surgery. MethodsIn this study, 32 eyes of 30 patients who underwent Nd:YAG laser treatment for PCO were evaluated. Visual acuity (VA), intraocular pressure (IOP), central macular thickness (CMT) with optical coherence tomography device (OCT), ganglion cell layer (GCL), inner plexiform layer (IPL), retinal nerve fiber layer (RNFL) and subfoveal choroidal thickness (SCT) were measured. Choroidal vascular index (CVI) was calculated from HD line images obtained by spectral domain OCT with the software Image J. ResultsThe mean age of the patients participating in the study was 60.1 ± 8.9 years. There was no significant difference in IOP, CMT, RNFL, GCL, IPL and SCT values ​​in all comparisons before and after laser (p>0.05 for all values). While Nd:YAG laser pretreatment CVI was 63.2 ± 3.2%, it was 66.8 ± 2.9% at 1 week and 67.1 ± 2.6% at 1 month after laser treatment. A significant difference was detected in the comparison of pre-laser CVI and post-laser 1 week and 1 month CVI (p<0.05 for all values). DiscussionCVI was found to be significantly higher in the post-laser period in patients who underwent Nd:YAG laser. As far as the author knows, this study is the first research in the literature to evaluate this relationship. CVI can be used to evaluate choroidal vascular changes after Nd:YAG laser.

Factors Associated with Reclosure of Posterior Capsule Aperture by Flat Opacifications with Pearls after Nd:YAG Laser Posterior Capsulotomy.

In this retrospective case series, we investigated factors associated with posterior capsule aperture (PCA) reclosure following neodymium-yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy. The study encompassed patients who underwent cataract surgery with intraocular lens (IOL) implantation or a combined vitrectomy, cataract surgery, and IOL implantation between 2009 and 2022. PCA reclosure was observed in 22 eyes of 17 patients: 45% (10 eyes) underwent the triple procedure, and 55% (12 eyes) received cataract surgery with IOL implantation. In our clinic, 14% of patients were given IOLs with a 4% water content, while 73% (13 eyes) of those experiencing PCA reclosure had IOLs with a 4% water content. The mean interval between Nd:YAG capsulotomies was notably shorter than that between the initial cataract surgery and the first Nd:YAG laser capsulotomy. We also identified five stages of PCA reclosure progression. In conclusion, IOL water content may be linked to PCA reclosure, and the time to recurrence is shorter with each successive reclosure. Further research is needed to verify these findings and uncover additional contributing factors.

Focused Nanosecond Pulsed Laser‐Induced Homogeneous Nucleation in Undercooled Oxide Melts

Induced homogeneous nucleation of undercooling melt is a fundamental challenge with exciting implications for composite ceramic and metal alloy materials. Nucleation can be induced externally, but physical mechanical properties reduce due to the introduction of impurities. Herein, a novel focused nanosecond pulsed laser‐induced nucleation approach is demonstrated for oxide ceramic melts at undercooled state. Using a self‐made aerodynamic levitation setup, the pulsed laser‐induced nucleation is controlled by optimizing the pulse energy density at different undercooled temperatures. Exploiting this approach, nucleation and growth are observed from surface of undercooled alumina (Al2O3) and neodymium yttrium aluminum garnet (Nd:YAG) melts with high‐speed camera. The undercooling sample experiences a nucleate–solidify–recalescence–remelting–recalescence–solidify process. The correlation between nucleation time and undercooling temperature confirms that the undercooled melt is nucleated homogeneously by the pulsed laser. The special microstructural of samples agrees well with the prediction of two‐step nucleation theory. Therefore, an assumption for the nucleation mechanism with the high‐speed images and the microstructure analysis is proposed. This proposed method may provide a different perspective for the classical nucleation theory of homogeneous nucleation.

Poly(2-hydroxyethyl methacrylate) surface chemistry and modulus differentially modulate neutrophils and lens epithelial cells-possible implications in cellular responses to intraocular lenses.

During cataract surgery, diseased lenses in the eye are surgically removed and replaced with polymeric artificial intraocular lenses (IOLs). Patients can experience a complication called posterior capsular opacification (PCO) that is corrected through the removal of part of the posterior capsule using a neodymium: yttrium-aluminum-garnet (Nd-YAG) laser to restore the optical path. These interventions have increased costs and can damage the retina and the IOL. PCO develops when lens epithelial cells (LECs) proliferate, migrate, and undergo epithelial-to-mesenchymal transition. Neutrophils involved in the immune response triggered during implantation impact LEC behavior and produce damaging neutrophil extracellular traps (NETs). In this research, poly(2-hydroxyethyl methacrylate) (PHEMA) -based disks were synthesized with varying amounts of comonomer (HEMA with 0, 2, and 12 mol% MMA) and functionalized with carboxyl and amine groups, yielding nine different hydrogels. Material and chemical properties of the disks were characterized, and neutrophil-like HL60 cells and B3 LECs were incubated with the disks. HL60 cell behavior was more strongly influenced by chemical functionalization than by mechanical properties with increases in adherence and NET accumulation. Conversely, the behavior and viability of B3 LECs were more strongly influenced by mechanical properties with increases in cell adhesion and α-SMA expression with increasing compressive moduli. Interestingly, B3 LECs had decreased viability and increased α-SMA expression when cultured on PHEMA2 disks pretreated with isolated NETs. Critical to the understanding of PCO and its prevention are both surface chemistry and mechanics as well as the inflammatory response.

GOLD AND SILVER NANOPARTICLES AS COMPUTED TOMOGRAPHY (CT) CONTRAST AGENTS PRODUCED BY A PULSED LASER ABLATION TECHNIQUE: STUDY In-vitro AND In-vivo

High-purity metal nanoparticles such as gold and silver nanoparticles become an interesting subject for application in the medical field. Using the laser ablation approach, these nanoparticles were successfully synthesized in this present work. Experimentally, a pulse neodymium yttrium aluminum garnet laser (1064 nm, 30 mJ, 10 Hz) was used to irradiate high-purity metals immersed in an iodine liquid medium. Purple, yellow, and dark purple colloidal nanoparticles of Au, Ag, and Au-Ag were successfully synthesized. The results certified that all nanoparticles have a spherical shape; Au nanoparticles had an average diameter of 26 nm and a standard deviation of 4 nm, while Ag nanoparticles had an average diameter of 24 nm and a standard deviation of 5 nm. The diameter distribution of AuAg nanoparticles is extraordinarily vast, ranging from 18 to 80 nm. Colloids of mixed Au-Ag nanoparticles had the highest Hounsfield Units (HU) value in an in vivo test, with a value of 302. This was supported by the results of an in vitro contrast enhancement evaluation, which determined that a mixture of Au-Ag nanoparticles provided the best contrast enhancement compared to other colloids. These results confirmed that the Au-Ag nanoparticles are very suitable as contrast agents in CT.

A Practical Approach to Cosmetic Tattoo Removal with the Nd:YAG Laser.

The Q-switched neodymium-yttrium aluminium garnet (Nd:YAG) laser remains the gold standard method for tattoo removal including cosmetic tattoos. Modern picosecond lasers are referenced to the Nd:YAG laser and essentially do the same job. Persons with cosmetic tattoos in the face are especially eager to achieve perfect removal or correction and from start are critical to suboptimal results. Customers mostly request complete removal; sometimes the goal is fast treatment and bleaching to prepare for a cover up tattoo. Removal or correction of eyebrows is the largest group, followed by lip tattoos and eyeliners. The article gives a systematic and stepwise introduction to routine cosmetic tattoo removal by laser in an Austrian private medical practice. Rationales and selection of customers who can benefit from treatment, preparation, performance, and aftercare is reviewed. Emphasis is given to qualified power adjustment of the laser equipment and the treatment strategy, e.g. the delicate navigation between efficient removal and the risk of short-term and long-term adverse effects. Treatment relies on a partnership between provider and customer. Over the months of treatment, customers gain more insight into the possibilities of treatment, so that they get an understanding of the realistic results that can be achieved. Therefore, customers are also satisfied even with results that are not always optimal since best treatment was given a fair chance.

High-energy Q-switched Nd:YAG oscillator and amplifier development for large-mode, low-alignment sensitivity applications

High pulse energy, low-alignment sensitivity master-oscillator power-amplifier (MOPA) systems enable portable long range laser devices. Comprehensive amplifier modelling is an essential tool in producing efficient, optimised amplfication capable of producing high pulse energies. This paper outlines the development of a large-mode, low-alignment sensitivity neodymium yttrium aluminium garnet (Nd:YAG) (MOPA) system, achieving a total output pulse energy of 265 mJ with an optical efficiency of 18%. A Q-switched diode-pumped Nd:YAG zig-zag oscillator is developed with an output pulse energy of 98 mJ and slope efficiency of 31%. Through the use of an intracavity aperture, the beam quality exhibited an M2 of 4.3 and 4.6 and far field divergence of 1.3 mrad and 1.2 mrad in the horizontal and vertical, respectively. The oscillator output is amplified within a diode-pumped Nd:YAG zig-zag amplifier with a system amplification of 2.8. Comprehensive amplifier modelling based on a Frantz-Nodvik analysis is demonstrated, with the saturation characteristics suggesting a route to further energy enhancement and highlighting the necessity for amplifier modelling in high energy system design.

The Evaluation of the 1318 nm Diode Laser in Open Liver Surgery.

Simple SummaryThe surgical treatment of liver metastases but also of primary liver tumors is of particular clinical relevance in view of their high incidence. As a therapy option with a prospect of long-term survival in curative intent, liver resection plays a crucial role in modern multimodal treatment concepts. Advances in surgical and perioperative medicine have led to a reduction of procedural mortality to less than 5% and morbidity to around 35–45% and have rendered liver resections from high risk to routine procedures. Several comparisons of common parenchymal dissection techniques showed no specific advantages in favor of one of the methods in terms of morbidity, mortality and intraoperative blood loss. The aim of our retrospective study was to evaluate the 1318 nm diode pumped neodymium-yttrium aluminum garnet laser in open liver surgery. It could be shown that liver resections using the 1318 nm surgical laser can be carried out with an acceptable risk and are equally safe compared to conventional resection methods with comparatively little blood loss and favorable oncological surrogate outcomes.(1) Background: Numerous dissection instruments are available for liver resection. So far, there has been no evidence in favor of a specific dissection device effecting a reduction in postoperative mortality and morbidity or a reduction in intraoperative blood loss. The aim of the study was to evaluate the safety of liver resection with the 1318 nm surgical laser. (2) Methods: 151 consecutive patients who underwent liver resection using the 1318 nm surgical laser (n = 119) or conventional dissection methods (n = 32) were evaluated retrospectively. As primary outcome, postoperative complications were assessed using the Clavien–Dindo classification. Secondary outcomes were postoperative mortality, reoperations and reinterventions, intraoperative blood loss, the need for vascular control using the Pringle maneuver and oncological safety assessed through histopathological evaluation of resection margins. (3) Results: For liver resections using the 1318 nm surgical laser, the postoperative morbidity (41.2% vs. 59.4%, p = 0.066), mortality (1.7% vs. 3.1%, p = 0.513) and the reoperation rate (2.5% vs. 3.1%, p = 1.000) were not significantly different from conventional liver resections. In the laser group, a lower reintervention rate (9.2% vs. 21.9%, p = 0.050) was observed. The oncological safety demonstrated by a tumor-free resection margin was similar after laser and conventional resection (93.2% vs. 89.3%, p = 0.256). The median intraoperative blood loss was significantly lower in the laser group (300 mL vs. 500 mL, p = 0.005) and there was a significantly lower need for a Pringle maneuver (3.4% vs. 15.6%, p = 0.021). (4) Conclusions: Liver resections using the 1318 nm surgical laser can be routinely performed with a favorable risk profile. Compared to alternative resection methods, they are associated with low blood loss, appear adequate from an oncological point of view, and are not associated with increased mortality and morbidity.

Topical 0.1% Nepafenac versus 0.09% Bromfenac Eye Drops for Inflammation after Laser Peripheral Iridotomy: A Randomized Controlled Trial

To assess the safety and efficacy of 0.1% nepafenac versus 0.09% bromfenac eye drops in controlling inflammation after neodymium yttrium-aluminum-garnet (YAG) laser peripheral iridotomy (LPI). Single-masked, single-center, randomized controlled trial. One hundred and sixty eyes of patients with primary angle-closure suspect (PACS) and primary angle closure (PAC) undergoing bilateral LPI. Patients were randomized in a 1:1 ratio to receive 0.1% nepafenac thrice daily or 0.09% bromfenac eye drops twice daily for 2 weeks after neodymium YAG LPI. Assessment was performed by masked investigators at 2 weeks after LPI. A Glaucoma Symptom Scale (GSS) questionnaire was administered both at baseline and 2 weeks after LPI. Subjective comfort scores to the study medications were assessed on the basis of a Likert scale at 2 weeks after LPI. In patients with bilateral PACS or PAC, the right eye was analyzed, and in asymmetrical disease (i.e., when one eye had PACS and the other eye had PAC), the eye with PAC was analyzed. The primary outcome (end point) was uncontrolled inflammation, defined as symptomatic inflammation within 1 week after LPI, the presence of anterior chamber cells at 2 weeks, or rebound inflammation after medication discontinuation. The secondary outcome was patient-reported comfort levels with study medications based on the GSS and Likert scale. At 2 weeks after LPI, 7 patients (6 with PACS and 1 with PAC) in the nepafenac group and 2 patients with PACS in the bromfenac group achieved the primary end point, without a difference between the medication groups (P= 0.09). Post-LPI burning, smarting, and stinging was more common in the bromfenac group (P= 0.01), which also had a higher comfort score on the Likert scale (P= 0.004). The need for repeat LPI was comparable (10.0% in the nepafenac group vs. 15.4% in the bromfenac group; P= 0.22). A multivariate analysis revealed that a greater number of laser shots was associated with the need for repeat LPI (odds ratio, 1.05; 95% confidence interval, 1.00-1.10; P= 0.04). Topical 0.09% bromfenac is noninferior to 0.1% nepafenac in controlling inflammation after LPI in eyes with PACS and PAC. Nepafenac may be associated with higher patient-reported comfort.

In vitro analysis of mechanism of pulsed-laser thrombolysis.

Thrombolytic therapy in the treatment of cardiogenic acute cerebral embolism caused by coagulated blood carries the risk of hemorrhagic complications, and there is a need to develop safer and more reliable treatment methods. Laser thrombolysis therapy, which utilizes the difference in energy absorption between the thrombus and the arterial wall, has shown promise as a new treatment method because it can selectively act only on the thrombus. It has not been applied clinically, however, and one of the main reasons for this is that its underlying mechanism has not been elucidated. We developed a pulse laser thrombolysis system for treating cerebral blood vessels that consists of a diode-pumped solid-state neodymium-yttrium aluminum garnet laser, which has excellent stability and maintainability and is suitable for clinical applications coupled to a small-diameter optical fiber. Moreover, we analyzed the mechanisms that occur during pulsed laser irradiation of transparent glass tubes and gelatin phantoms. We found that bubbles form as a thermal effect in addition to ablation of the pulsed laser irradiation. Furthermore, we detected no shock waves or water jets associated with the bubbles. We analyzed the bubbles’ dynamics and growth rate, and their effect on a rabbit blood clot phantom. We concluded that the bubbles generated by the laser irradiation physically cut the thrombus and thereby had a thrombectomy effect. We believe that this study will clarify the mechanism of laser thrombolysis therapy and contribute greatly to the realization of its clinical application.

Lacteocrumenasia

Capsular bag distension syndrome (CBDS) is a rare complication of cataract surgery characterized by collection of turbid fluid between the posterior surface of the intraocular lens (IOL) and the posterior capsule. Here, we report a case of CBDS presenting 7 years after uneventful cataract surgery. Patient presented with blurring of vision in the right eye and his best corrected visual acuity (BCVA) was 6/9 N6. Slit lamp examination showed collection of turbid fluid between IOL and posterior capsule, and the opaque fibrosed capsulorhexis margin was adherent to the optic of IOL which was well placed within the bag. Patient underwent neodymium yttrium aluminium garnet (ND-YAG) laser posterior capsulotomy to release the fluid into the vitreous cavity. 6 weeks after the procedure his BCVA improved to 6/6 N6.

Synthesis of Tin Oxide Nanoparticles by Pulsed Laser Ablation Method Using Low-Energy Nd: YAG Laser as an Antibacterial Agent

Tin oxide nanoparticles (SnNPs) are very useful to be employed as an antibacterial agent for both gram-positive and gram-negative bacteria. In this present work, the synthesis of SnNPs was successfully carried out using the neodymium yttrium aluminum garnet (Nd:YAG) laser with a wavelength of 1064 nm, pulse duration of 7 ns, and a laser frequency of 10 Hz. Experimentally, a pulse Nd:YAG laser was directed and focused on a high-purity tin (Sn) metal, immersed in various liquid media including pure water and ethylene glycol. A brownish colloidal colour was produced both in pure water and ethylene glycol liquid media. Characterizations of tin oxide nanoparticles were made using UV-Vis, EDX, FTIR, and TEM. UV-Vis characterization produced absorbance values in pure water and ethylene glycol media of 1.314 a.u. and 1.119 a.u., respectively. TEM images show that the shape of tin oxide nanoparticles produced is spherical. Measurement of nanoparticle size distribution was made using image-J software and the average diameter of nano-size in the ethylene glycol medium is 12.55 nm, which is smaller than the size in the pure water of 19.98 nm. The EDX spectrum analysis results show that there are only Sn and O atoms in colloidal tin oxide nanoparticles (SnNPs). FTIR results show the formation of tin oxide (SnO2) spectrum at the wavenumber of 629.03 cm-1. The produced colloidal SnNPs were then applied as an antibacterial agent of E. coli using the disk diffusion method. Results certified that various concentrations of SnNPs of 10 ppm, 20 ppm, and 30 ppm gain the diameter of inhibition zone (DIZ) in sequence 6.50 mm, 6.75 mm, and 9.50 mm. Based on these experimental results, it shows that the higher the concentration of SnNPs given, the greater the ability to degrade and inhibit bacteria.

Temperature dependence of the small-signal gain of a Cr3+ and Nd3+ co-doped Y3Al5O12 ceramic

There is a demand for higher-efficiency neodymium and chromium co-doped yttrium aluminum garnet (Nd/Cr:YAG) ceramics that can be excited by broadband light sources, such as flash lamps. We experimentally investigated the temperature dependence of the gain coefficient of a Nd/Cr:YAG ceramic (Nd: 1.0 at%, Cr: 2.0 at%). The gain coefficient at 1064 nm decreased with increasing temperature when Nd3+ was directly excited at 808 nm. However, when Nd3+ was excited via energy transfer from Cr3+ excited at 610 nm, the gain coefficient increased with increasing temperature. This temperature dependence was theoretically explained by solving the rate equations for Nd/Cr:YAG. Nd/Cr:YAG ceramics pumped with flash lamps may provide good laser performance without loss of gain even at high temperatures.