• Archives of Plastic Surgery
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• v.48 no.4
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• pp.347-352
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• 2021

Background Mastectomy leaves unsightly scarring, which can be distressing to patients. Laser therapy for scar prevention has been consistently emphasized in recent studies showing that several types of lasers, including fractional ablation lasers, are effective for reducing scar formation. Nonetheless, there are few studies evaluating the therapeutic efficacy of ablative CO₂ fractional lasers (ACFLs). Methods This study had a randomized, comparative, prospective, split-scar design with blinded evaluation of mastectomy scars. Fifteen patients with mastectomy scars were treated using an ACFL. Half of each scar was randomized to "A," while the other side was allocated to group "B." Laser treatment was conducted randomly. Scars were assessed using digital photographs of the scar and Vancouver scar scale (VSS) scores. Histological assessments were also done. Results The mean VSS scores were 2.20±1.28 for the treatment side and 2.96±1.40 for the control side. There was a significant difference in the VSS score between the treatment side and the control side (P=0.002). The mean visual analog scale (VAS) scores were 4.13±1.36 for the treatment side and 4.67±1.53 for the control side. There was a significant difference in VAS score between the treatment side and the control side (P=0.02). Conclusions This study demonstrated that early scar treatment using an ACFL significantly improved the clinical results of the treatment compared to the untreated scar, and this difference was associated with patient satisfaction.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.275-282
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• 2008

Objective: The purpose of this study was to investigate the effect of using laser for ceramic bracket bonding of porcelain surfaces and to compare it with conventional treatment of porcelain surfaces. Methods: Ninety feldspathic porcelain specimens were divided into 9 groups of 10, with each group having different surface treatments performed. Surface treatment groups were orthophosphoric acid, orthophosphoric acid with silane, hydrofluoric acid, hydrofluoric acid with silane, sandblasted, sandblasted with silane, laser etched, laser etched with silane, and glazed surface served as a control group. In the laser etched groups, the specimens were irradiated with 2-watt superpulse carbon dioxide ($CO_2$) laser for 20 seconds. Ceramic brackets were bonded with light-cure composite resin and all specimens were stored in water at $37^{\circ}C$ for 24 hours. Shear bond strength was determined in megapascals (MPa) by shear test at 1 mm/minute crosshead speed and the failure pattern was assessed. For statistical analysis, one-way ANOVA and tukey test were used. Results: Statistical analysis showed significant differences between the groups. The HFA + S group showed the highest mean shear bond strength ($13.92{\pm}1.94\;MPa$). This was followed by SB + S ($10.16\;{\pm}\;1.27\;MPa$), HFA ($10.09\;{\pm}\;1.07\;MPa$), L + S ($8.25\;{\pm}\;1.24\;MPa$), L ($7.86\;{\pm}\;0.96\;MPa$), OFA + S ($7.22\;{\pm}\;1.09\;MPa$), SB ($3.41\;{\pm}\;0.37\;MPa$), OFA ($2.81\;{\pm}\;0.37\;MPa$), G ($2.46\;{\pm}\;1.36\;MPa$), Bond failure patterns of HFA and silane groups, except L + S, were cohesive modes in porcelain while adhesive failure was observed in the control group and the rest of the groups. Conclusions : A 2-watt superpulse $CO_2$ laser etching of porcelain surfaces can provide a satisfactory result for porcelain surface treatment for ceramic bracket bonding. Laser irradiation may be an alternative conditioning method for the treatment of porcelain surfaces.

• Korean Journal of Head & Neck Oncology
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• v.18 no.1
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• pp.36-40
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• 2002

Background and Objectives: To determine if laser endoscopic microsurgery is a reliable and appropriate approach in the treatment of laryngeal carcinomas. Materials and Methods: Retrospective study of 62 patients treated with CO2 laser from June 1988 to November 2000 at Seoul National University Hospital for laryngeal squamous cell carcinoma. All patients were treated with curative intention. Fifty three untreated patients with laryngeal carcinoma (39 glottic and 14 supraglottic carcinoma patients) had primary carbon dioxide laser microsurgery. Nine radiation failure patients were treated. Postoperative radiotheray was done for 17 patients. Neck dissection was performed simultaneously for 4 supraglottic cases with cervical nodal metastasis. Mean follow-up duration was 40 months. Results: In primary laser surgery group, distribution of tumors (American Joint Committee on Cancer, 1997) were 38 cases with Tl, 13 cases with T2, 2 cases with T3. Cure rate was 88.7%(47/53) and local control rate was 92.5%(49/53). Larynx was preserved in 94%(50/53) of patients. The overall 5-year survival rate(Kaplan-Meier) was 81.5%. In radiation failure group, 56% of patients were recurred after laser surgery. Conclusion: Laser surgery could be a better treatment modality for early laryngeal cancers and selected advanced cases. Additional radiation therapy should be considered if resection margin is not satisfactory.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.404-416
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• 2020

Bacteria that are resistant to high temperatures and alkaline environments are essential for the biological repair of damaged concrete. Alkaliphilic and halotolerant Bacillus sp. AK13 was isolated from the rhizosphere of Miscanthus sacchariflorus. Unlike other tested Bacillus species, the AK13 strain grows at pH 13 and withstands 11% (w/v) NaCl. Growth of the AK13 strain at elevated pH without urea promoted calcium carbonate (CaCO₃) formation. Irregular vaterite-like CaCO₃ minerals that were tightly attached to cells were observed using field-emission scanning electron microscopy. Energy-dispersive X-ray spectrometry, confocal laser scanning microscopy, and X-ray diffraction analyses confirmed the presence of CaCO₃ around the cell. Isotope ration mass spectrometry analysis confirmed that the majority of CO₃^2- ions in the CaCO₃ were produced by cellular respiration rather than being derived from atmospheric carbon dioxide. The minerals produced from calcium acetate-added growth medium formed smaller crystals than those formed in calcium lactate-added medium. Strain AK13 appears to heal cracks on mortar specimens when applied as a pelletized spore powder. Alkaliphilic Bacillus sp. AK13 is a promising candidate for self-healing agents in concrete.

• Animal cells and systems
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• v.16 no.6
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• pp.469-478
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• 2012

Sex hormones have long been considered to play an important role in bone turnover rate, periodontal diseases, and wound healing. We have studied the effect of porcine testis steroid extract (PTSE), an extract of porcine testes, which holds a good ratio of 19-nortestosterone (nandrolone), testosterone, androstenedione, $17{\beta}$-estradiol, and estrone, on the healing rate of a standardized full-thickness linear wound on the back of the rat. Skin punch or carbon dioxide ($CO_2$) laser methods were used to create the deep skin injury in two groups of animals. The animals were treated with the PTSE cream, control cream and Vaseline (control) to find out the effect in re-epithelialization, contraction, and formation of granulation and scar tissues. Histological examination after 21 days showed 100, 87.4, and 80.5% recovery of epidermis, dermis, and hypodermis, respectively in the PTSE-treated animals. Similarly, on the 15th day of treatment, complete healing of intact skin was observed in the PTSE cream-treated animals among the laser radiation group. Even though the beginning of re-epithelialization phase and completion of serum crust formation was also observed in the base cream- and Vaseline-treated animals respectively, the complete healing cycle was observed only in the PTSE-treated group. The white blood cell count in the PTSE-treated group showed that PTSE cream is nontoxic to animals.