• Journal of Periodontal and Implant Science
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• v.41 no.4
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• pp.201-207
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• 2011

Purpose: The aim of this study is to compare two different gingival depigmentation techniques using an erbium:yttrium-aluminum-garnet (Er:YAG) laser and rotary instruments. Methods: Two patients with melanin pigmentation of gingiva were treated with different gingival depigmentation techniques. Ablation of the gingiva by Er:YAG laser was performed on the right side, and abrasion with a rotary round bur on the opposite side. Results: The patients were satisfied with the esthetically significant improvement with each method. However, some pigment still remained on the marginal gingival and papilla. The visual analog scale did not yield much difference between the two methods, with slightly more pain on the Er:YAG laser treated site. Conclusions: The results of these cases suggest that ablation of the gingiva by an Er:YAG laser and abrasion with a rotary round bur is good enough to achieve esthetic satisfaction and fair wound healing without infection or severe pain. Prudent care about the gingival condition, such as the gingival thickness and degree of pigmentation along with appropriate assessment is needed in ablation by the Er:YAG laser procedure.

• Korean Journal of Acupuncture
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• v.40 no.4
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• pp.141-148
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• 2023

Objectives : The purpose of this study is to investigate on the application of the yttrium aluminum garnet (YAG) lasers for acupoints irradiation. Methods : We conducted a systematic search for peer-reviewed studies published from inception to November 2023, in the following electronic databases: PubMed, Scopus, and Web of Science in English, Science ON, Oriental Medicine Advanced Searching Integrated System (OASIS) and Research Information Sharing Service (RISS) in Korean, and China National Knowledge Infrastructure (CNKI) and Wanfang in Chinese, and Japan Science Technology Information Aggregator, Electronic (J-STAGE) and Citation Information by NII (CiNii) in Japanese. Inclusion criteria were original articles including clinical and experimental studies related with YAG lasers for acupoints including Ashi or meridian sinews. Results : Among the 8 selected studies, there were 7 studies on human subjects and 1 study on animals, 7 studies on Nd:YAG (1,064 nm) laser, and 1 study on Er:YAG (2,940 nm) laser. A total of 16 acupoints were used, 15 of which were in the face and 1 of which was located in the foot. In addition, there were two studies using Ashi. 4 studies looked at the effect of pain relief, 2 studies looked at safety, 1 study looked at changes in blood flow, and 1 study looked at the effect of skin care. There were no reported adverse events, and the YAG laser was confirmed to be safe and effective in pain relief, beautifying the skin, and increasing blood flow. Conclusions : We suggest that high intensity YAG lasers can be applied to laser acupuncture or laser moxibustion. YAG lasers are considered to be worth using for various clinical indications of Korean medicine because of photobiomodulation effects, analgesic action, and deep penetration depth. Further scientific research and clinical evidences should be warranted.

• Archives of Plastic Surgery
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• v.42 no.1
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• pp.52-58
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• 2015

Background The erbium:yttrium scandium gallium garnet (Er:YSGG) laser differs from other laser techniques by having a faster and higher cure rate. Since the Er:YSGG laser causes an appropriate proportion of ablation and coagulation, it has advantages over the conventional carbon dioxide ($CO_2$) laser and the erbium-doped yttrium aluminum garnet (Er:YAG) laser, including heating tendencies and explosive vaporization. This research was conducted to explore the effects and safety of the Er:YSGG laser. Methods Twenty patients participated in the pilot study of a resurfacing system using a 2,790-nm Er:YSGG laser. All patients received facial treatment by the 2,790-nm Er:YSGG laser system (Cutera) twice with a 4-week interval. Wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture were measured. Results Study subjects included 15 women and five men. Re-epithelization occurred in all subjects 3 to 4 days after treatment, and wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture within 6 months of treatment. Conclusions The 2,790-nm YSGG laser technique had fewer complications and was effective in the improvement of scars, pores, wrinkles, and skin tone and color with one or two treatments. We expect this method to be effective for people with acne scars, pore scars, deep wrinkles, and uneven skin texture and color.

• The Korean Journal of Ceramics
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• v.1 no.2
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• pp.91-95
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• 1995

Polycrystalline bismuth- and aluminum- substituted dysporsium and yttrium iron garnet (Bi2R3-xAlyFe5-yO12, R=Dy or Y, $0\leqx\leq3, \; 0\leqy\leq3$) films have been prepared by pyrolysis. The crystallization temperatures, the solubility limit of bismuth ions into the garnet phase, and magnetic and magneto-optic properties of the films have been investigated as a function of bismuth and aluminum concentration. It was found that the crystallization temperatures as a function of bismuth and aluminum concentration. It was found that the crystallization temperatures of these films rapidly decreased as bismuth concentration. It was found that the crystallization temperatures of these films rapidly decreased as bismuth concentration (x) increased up to x=1.5 and then remained temperatures of these films rapidly decreased as bismuth concentration (x) increased up to x=1.5 and then remained unchanged at x>1.5, whereas, showed no changes as aluminum concentration (y) increased up to y=1.0 and then gradually increased at y>1.0. The solubility limit of bismuth ions was x=1.8 when y=0 but increased to x=2.3 when y=1.0. It was demonstrated that the magnetic and magneto-optic properties of the dysprosium iron garnet films could be tailored by bismuth and aluminum substitution suitable for magneto-optic recording as follows. The saturation magnetization and coercivity data obtained for the films indicated that the film composition at which the magnetic compensation temperature became room temperature was y=1.2 when x=1.0. Near this composition the coercivity and the squareness of the magnetic hysteresis loop of the films were several kOe and unit, respectively. The Curie temperatures of the films increased with the increase of x but decreaed with the increase of y, and was 150-$250^{\circ}C$ when x=1.0 and y=0.6-1.4. The Faraday rotation at 633 nm of the films increased as x increased but decreased as y increased, and was 1 deg/$\mu\textrm{m}$ when x=1.0 and y=1.0. Based on the data obtained, the appropriate film composition for magneto-optic recording was estimated as near x=1.0 and y=1.0 or $BiDy_2AlFe_4O_{12}$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.1
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• pp.18-21
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• 2017

In this study, spherical monodispersed cerium-doped yttrium aluminum garnet (YAG : $Ce^{3+}$) phosphor particles were synthesized via homogeneous precipitation method using the mixed solution of yttrium nitrate, cerium nitrate, aluminum nitrate, ammonium aluminum sulfate, and urea as a precipitant. During the process of precursors of monodispersed YAG : $Ce^{3+}$, aluminum ions which form spherical aluminum compounds precipitated first and yttrium compounds precipitated onto the surface of the existing spherical aluminum compounds. Drying process using lyophilization could obtain monodispered spherical YAG : $Ce^{3+}$ particles compare to using oven. The thermal calcination process of YAG : $Ce^{3+}$ precursors under the temperature of $1200^{\circ}C$ for 6 h was enough to obtain 400~500 nm sized YAG particles with pure YAG phase.

• Medical Lasers
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• v.9 no.2
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• pp.142-149
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• 2020

Background and Objectives A picosecond-domain laser treatment using a microlens array (MLA) or a diffractive optical element elicits therapeutic micro-injury zones in the skin. This study examined the patterns of tissue reactions after delivering multiple pulses of 1,064-nm, MLA-type, picosecond neodymium:yttrium-aluminum-garnet laser treatment. Materials and Methods Multiple pulses of picosecond laser treatment were delivered to ex vivo human or brown micropig skin and analyzed histopathologically. A high-speed cinematographic study was performed to visualize the multiple pulses of picosecond laser energy-induced skin reactions in in vivo human skin. Results In the ex vivo human skin, a picosecond laser treatment at a fluence of 0.3 J/cm² over 100 non-stacking passes generated multiple lesions of thermally-initiated laser-induced optical breakdown (TI-LIOB) in the epidermis and dermis. In the ex vivo micropig skin, stacking pulses of 20, 40, 60, 80, and 100 at a fluence of 0.3 J/cm² generated distinct round to oval zones of tissue coagulation in the mid to lower dermis. High-speed cinematography captured various patterns of twinkling, micro-spot reactions on the skin surface over 100 stacked pulses of a picosecond laser treatment. Conclusion Multiple pulses of 1,064-nm, MLA-type, picosecond laser treatment elicit marked TI-LIOB reactions in the epidermis and areas of round to oval thermal coagulation in the mid to deep dermis.

• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.174-179
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• 2003

We construct a four-level system where a metastable state is included in an $Er^{3＋}$ Doped Yttrium aluminum garnet (YAG) crystal. Because of the action of the coherent field, the traditional light amplification with inversion can be exhibited with remarkable variation. As a result, we propose a method to achieve the gain equalization by atomic coherence. At the same time, we find that the high index of refraction accompanied by vanishing absorption can also be reached in this model. We also find that a higher index of refraction with zero absorption can be easily obtained when the coherent field is off resonance.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.657-659
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• 2004

Trivalent cerium ($Ce^{3+}$) activated yttrium aluminum garnet ($Y_3Al_5O_{12}$, YAG) phosphor thin films were deposited on quartz glass substrates by rf magnetron sputtering. The effects of sputtering parameters and annealing condition on the luminescent properties were investigated. The sputtering parameters were $O_2$/Ar gas ratio, rf power, and deposition time. The films were annealed at 1200 $^{\circ}C$ for 5 hours in $N_2+$vacuum atmosphere. Polycrystalline YAG:Ce thin film phosphor could be obtained with a gas ratio of $O_2$/(Ar+$O_2$)=0.5 after post-annealing. PL spectra excited at 450 nm showed a yellow single band at 550 nm.

• Journal of the Korean Ceramic Society
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• v.35 no.9
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• pp.911-916
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• 1998

By using {{{{ { { {Y }_{3 }Al }_{5 }O }_{12 } }} (YAG) and SiO2 as sintering additives the effect of the composition of sintering ad-ditives on microstructure and mechanical properties of the hog-pressed and subsequently annealed SiC ma-terials were investigated. Microstructures of sintered and annealed materials were strongly dependent onthe composition of sintering additives. The average diameter and volume fraction of elongated grains in an-nealed materials increased with the SiO2/YAg ratio while the fracture toughness increased with the SiO2/YAg ratio. The average MPa.{{{{ { m}^{1/2 } }} respectively. Typical strength and fracture toughness of an annealed material with SiO2/YAg ra-tionof 0.67 were 371 MPa and 5.6 MPa.{{{{ { m}^{1/2 } }} respectively.

• Journal of Chest Surgery
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• v.44 no.4
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• pp.311-313
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• 2011

Hemangiomas that arise in cervical esophagus are extremely rare, representing 3.3% of all benign esophageal tumors. Although endoscopic mucosal resection (EMR) and potassium titanyl phosphate/yttrium aluminum garnet (KTP/YAG) laser therapy have been used with success for small tumors, the safety and efficacy in the case of large tumors remains uncertain. We report the successful resection of cervical esophageal hemangioma through a cervical esophagotomy in a patient with thyroid cancer who needed a cervical collar incision.