• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.124-129
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• 2005

Pro-inflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin-12 (IL-12) and interleukin $(IL-1)-{\beta}$, play a key role in causing inflammatory diseases, which are rheumatoid arthritis, Crohn's disease and sepsis. Accumulating evidences suggest that low level laser irradiation (LLLI) may have an anti-inflammatory action. However, there are few data regarding down regulation of Th1 immune response by using the diod typed laser emitting device for human patients. As a fundamental step in order to address this issue, we investigated immunological impact of the low level laser irradiation (10 mw laser diode with a wavelength of 630 nm) on expression of pro-inflammatory cytokines in murine immunocytes (splenocytes and peritoneal macrophages) in vitro. The LLLI on lipopolysaccharide (LPS 100 ng/ml)-stimulated murine splenocytes and macrophages, clearly down regulated mRNA expression of $TNF-{\alpha}$ and IL-12 in dose-dependent manner. In addition, LLLI significantly inhibits the NO production in the LPS-stimulated murine macrophages. This data suggests that LLLI (wavelength of 630 nm) may exert an anti-inflammatory action via modulation of pro-inflammatory cytokine and NO production pathway.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.42-47
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• 2009

The propagation of an intense laser pulse through an upward density-gradient plasma in a self-modulated laser wakefield acceleration (SM-LWFA) is investigated by using particle-in-cell (PIC) simulations. In the fully relativistic and kinetic PIC simulations, the relativistic and kinetic effects including Landau damping enhance the electron dephasing. This electron dephasing is the most important factor for limiting the energy of accelerated electrons. However, the electron dephasing, which is enhanced by relativistic and kinetic effects in the homogeneous plasma, can be forestalled through the detuning process arising from the longitudinal density gradient. Simulation results show that the detuning process can effectively maintain the coherence of the laser wake wave in the spatiotemporal wakefield pattern, hence considerable energy enhancement is achievable. The spatiotemporal profiles are analyzed for the detailed study on the relativistic and kinetic effects. In this paper, the optimum slope of the density gradient for increasing electron energy is presented for various laser intensities.

• Progress in Medical Physics
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• v.6 no.1
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• pp.19-37
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• 1995

The use of lasers in medicine has opened up entirely new fields of therapy and diagnosis. The process in biotechnical applications of laser is basically different from traditional one in other technical field because of critical account to the human body. This paper surveys the principle of biomedical applications as well as possible future developments in laser medicine. In particular, the following subjects are extensively presented : 1) laser-tissue interaction, 2) therapeutic, and diagnostic technique, 3) laser op tical fiber for medicine, and 4) laser safety.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.24 no.2
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• pp.102-106
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• 2013

The cure rates for early stage laryngeal cancer are similar between laser cordectomy and radiation therapy. As well as the survival outcome, one of the main measures of success in treatment of early laryngeal cancer is voice outcome. Many studies have demonstrated that laser cordectomy and radiation therapy to be equivalent with regard to vocal outcome, whereas others favor radiation. Although such as somewhat disadvantages of voice outcome, laser cordectomy still remains a valid option. Since the patients who treated with laser may benefit from additional phonosurgery to improve postoperative vocal outcome. In this article, we reviewed the techniques of phonosurgery which can be used for laryngeal reconstruction after laser cordectomy. The indications for using each technique are discussed, with particular attention paid to functional outcomes following these reconstructive efforts.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1729-1731
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• 2003

Recently many solid-state laser systems were widely used in the medical applications. So it is necessary to study various optimal laser parameters for adopting new medical treatments. Alexandrite laser using switching mode power supply has designed and experimented to adjust a pulse repetition rate by PIC one-chip microprocessor. The fundamental results have been obtained during the first financial year in 2002. We will be able to find out the optimal hair removal characteristics by the repetitive experiments of Alexandrite laser as the parameters such as pulse repetition rate, pulse width, and pulse energy etc.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.37-41
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• 2009

We observe the proton signals produced by laser interaction with thin-foil targets of polyimide and of copper. We change the thickness of the polyimide target to $7.5{\mu}m$, $12.5{\mu}m$, and $50{\mu}m$. High-energy protons with the maximum energy of ${\sim}2.3\;MeV$ from $7.5{\mu}m$ thick polyimide are observed. This proton beam with the maximum energy of multi-MeV has various applications such as a proton shadowgraphy.

• Journal of Biomedical Engineering Research
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• v.33 no.3
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• pp.128-134
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• 2012

Currently, high-intensity laser therapy (HILT) is increasingly used in various muscle disorders like muscle tension. Our proposed study includes the development of the real-time monitoring system using a myotonometer for HILT. The developed system consists of a piezoelectric sensor and laser distance sensor for muscle stiffness monitoring during the treatments. The results demonstrated that the level of muscle tension was rapidly decreased after 3 minutes of the high-intensity laser treatment when compared to the control group. The combined HILT and realtime muscle tension monitoring system may help to evaluate the therapeutic procedure and efficient treatments for various muscle pains.

• The Journal of Natural Sciences
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• v.18 no.1
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• pp.9-16
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• 2007

The electro-optic Q-switching device for medical high power laser depends on the relation between the population inversion and the Q-switching time. The polarization changes in applied voltage must be experimented to use each $LiNbO_3$ crystal for Q-switching in high power laser.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.1
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• pp.7-10
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• 2008

The early glottic cancers are traditionally treated by radiotherapy or endoscopic surgery. The excellent effectiveness of both treatment modalities for local control, larynx preservation, and disease specific death is similar. Therefore, functional voice outcome after treatment is one of the most important factors in the choice of treatment for early glottic cancer. To assess the functional outcomes and compare the voice quality in patients with early glottic cancer treated with curative intent with radiotherapy or laser cordectomy, we performed literature review. Most studies showed that the voice quality after radiation therapy is slightly better than that after laser cordectomy. Subanalysis according to types of laser cordectomy, however, indicates that voice quality depends on type of laser cordectomy. Especially, type I or type II laser cordectomy might be superior to other types of laser cordectomy and radiation therapy. We conclude that the laser cordectomy is a good surgical alternative for properly selected early glottic cancer including professional voice users.

• Imaging Science in Dentistry
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• v.51 no.4
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• pp.429-438
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• 2021

Purpose: This study investigated the accuracy of laser-scanned models and 3-dimensional(3D) rendered cone-beam computed tomography (CBCT) compared to the gold standard (plaster casts) for linear measurements on dental arches. Materials and Methods: CBCT scans and plaster models from 30 patients were retrieved. Plaster models were scanned by an Emerald laser scanner (Planmeca, Helsinki, Finland). Sixteen different measurements, encompassing the mesiodistal width of teeth and both arches' length and width, were calculated using various landmarks. Linear measurements were made on laser-scanned models using Autodesk Meshmixer software v. 3.0 (Autodesk, Mill Valley, CA, USA), on 3D-rendered CBCT models using OnDemand 3D v. 1.0 (Cybermed, Seoul, Korea) and on plaster casts by a digital caliper. Descriptive statistics, the paired t-test, and intra- and inter-class correlation coefficients were used to analyze the data. Results: There were statistically significant differences between some measurements on plaster casts and laser-scanned or 3D-rendered CBCT models (P<0.05). Molar mesiodistal width and mandibular anterior arch width deviated significantly different from the gold standard in both methods. The largest mean differences of laser-scanned and 3D-rendered CBCT models compared to the gold standard were 0.12±0.23 mm and 0.42±0.53 mm, respectively. Most of the mean differences were not clinically significant. The intra- and inter-class correlation results were acceptable for all measurements(>0.830) and between observers(>0.801). Conclusion: The 3D-rendered CBCT images and laser-scanned models were useful and accurate alternatives to conventional plaster models. They could be used for clinical purposes in orthodontics and prostheses.