• Title/Summary/Keyword: low level laser

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Reliable Identification of Bacillus cereus Group Species Using Low Mass Biomarkers by MALDI-TOF MS

  • Ha, Miyoung;Jo, Hyeon-Ju;Choi, Eun-Kyeong;Kim, Yangsun;Kim, Junsung;Cho, Hyeon-Jong
    • Journal of Microbiology and Biotechnology
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    • v.29 no.6
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    • pp.887-896
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    • 2019
  • Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based pathogen identification relies on the ribosomal protein spectra provided in the proprietary database. Although these mass spectra can discern various pathogens at species level, the spectra-based method still has limitations in identifying closely-related microbial species. In this study, to overcome the limits of the current MALDI-TOF MS identification method using ribosomal protein spectra, we applied MALDI-TOF MS of low-mass profiling to the identification of two genetically related Bacillus species, the food-borne pathogen Bacillus cereus, and the insect pathogen Bacillus thuringiensis. The mass spectra of small molecules from 17 type strains of two bacilli were compared to the morphological, biochemical, and genetic identification methods of pathogens. The specific mass peaks in the low-mass range (m/z 500-3,000) successfully identified various closely-related strains belonging to these two reference species. The intensity profiles of the MALDI-TOF mass spectra clearly revealed the differences between the two genetically-related species at strain level. We suggest that small molecules with low molecular weight, 714.2 and 906.5 m/z can be potential mass biomarkers used for reliable identification of B. cereus and B. thuringiensis.

Proteome Analysis of Vernalization-Treated Arabidopsis thaliana by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

  • Cho, Mi-Ran;Lee, Kyung-Hyeon;Hyun, You-Bong;Lee, Il-Ha;Kim, Hie-Joon
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.427-431
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    • 2007
  • In order to gain insight into the molecular changes at the protein level in plants exposed to low temperature for a long period of time (vernalization), proteome analyses of vernalization-treated Arabidopsis thaliana have been carried out by two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry. Fourteen proteins including ATP binding/GTP binding/translation elongation factor and glycine-rich RNA-binding protein 7 (GRP7) showed differential expression in vernalization-treated Arabidopsis thaliana. GRP7 showed the most dramatic increase in expression suggesting its involvement in response to vernalization treatment.

Schottky Barrier Thin Film Transistor by using Platinum-silicided Source and Drain (플레티늄-실리사이드를 이용한 쇼트키 장벽 다결정 박막 트랜지스터)

  • Shin, Jin-Wook;Chung, Hong-Bay;Lee, Young-Hie;Cho, Won-Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.6
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    • pp.462-465
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    • 2009
  • Schottky barrier thin film transistors (SB-TFT) on polycrystalline silicon(poly-Si) are fabricated by platinum silicided source/drain for p-type SB-TFT. High quality poly-Si film were obtained by crystallizing the amorphous Si film with excimer laser annealing (ELA) or solid phase crystallization (SPC) method, The fabricated poly-Si SB-TFTs showed low leakage current level and a large on/off current ratio larger than 10), Significant improvement of electrical characteristics were obtained by the additional forming gas annealing in 2% $H_2/N_2$ ambient, which is attributed to the termination of dangling bond at the poly-Si grain boundaries as well as the reduction of interface trap states at gate oxide/poly-Si channel.

Photobiomodulation Therapy in Recovery of Peripheral Facial Nerve Damage

  • Choi, Ji Eun
    • Medical Lasers
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    • v.9 no.2
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    • pp.89-94
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    • 2020
  • Photobiomodulation (PBM) therapy has been investigated to enhance and accelerate the recovery of injured peripheral nerves. Based on the wide range of benefits of PBM therapy and its clinical relevance, this study reviewed the efficacy of PBM in injured facial nerves. The search was performed in the PubMed database to find relevant articles published over the last 10 years. Four animal studies, two randomized controlled studies, one case series, and five case reports were reviewed. Despite the various parameters, functional analysis showed that PBM therapy using near-infrared irradiation has beneficial effects on the recovery of the acute phase of the damaged facial nerve, especially when related to faster functional improvement. There were no reported adverse effects of PBM therapy.

Burn Wound Successfully Treated with 830-nm Light Emitting Diode Phototherapy Combined with Epidermal Growth Factor Solution

  • Lee, Hae-Jin;Kim, Young Koo
    • Medical Lasers
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    • v.8 no.2
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    • pp.94-96
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    • 2019
  • Burns are one of the most extensive injuries of soft tissues as well as skin, occasionally resulting in extensive, deep wounds and death. Burn wounds can lead to severe physical and psychological distress because of excessive scarring and skin contractures. Treatment of burn wounds has always been a challenging problem and many different methods have been used to treat such injuries. We report here on treating a patient with a burn wound using 830-nm light emitting diode (LED) phototherapy combined with epidermal growth factor (EGF) solution. After five daily sessions of LED with EGF solution treatment, the patient demonstrated nearly complete improvement with no remarkable side effects. We suggest that LED phototherapy combined with EGF solution could be an effective and safe treatment option for treating burn wounds.

A STUDY OF THE PRESSURE SOLUTION AND DEFORMATION OF QUARTZ CRYSTALS AT HIGH pH AND UNDER HIGH STRESS

  • Choi, Jung-Hae;Seo, Yong-Seok;Chae, Byung-Gon
    • Nuclear Engineering and Technology
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    • v.45 no.1
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    • pp.53-60
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    • 2013
  • Bentonite is generally used as a buffer material in high-level radioactive waste disposal facilities and consists of 50% quartz by weight. Quartz strongly affects the behavior of bentonite over very long periods. For this reason, quartz dissolution experiment was performed under high-pressure and high-alkalinity conditions based on the conditions found in a high-level radioactive waste disposal facility located deep underground. In this study, two quartz dissolution experiments were conducted on 1) quartz beads under low-pressure and high-alkalinity conditions and 2) a single quartz crystal under high-pressure and high-alkalinity conditions. Following the experiments, a confocal laser scanning microscope (CLSM) was used to observe the surfaces of experimental samples. Numerical analyses using the finite element method (FEM) were also performed to quantify the deformation of contact area. Quartz dissolution was observed in both experiments. This deformation was due to a concentrated compressive stress field, as indicated by the quartz deformation of the contact area through the FEM analysis. According to the numerical results, a high compressive stress field acted upon the neighboring contact area, which showed a rapid dissolution rate compared to other areas of the sample.

Development of a Signal Conditioning Circuit for Capacitive Displacement Sensors and Performance Evaluation (정전용량형 변위 센서 신호 처리 회로 개발 및 성능 평가)

  • Kim, Jong-Ahn;Kim, Jae-Wan;Eom, Tae-Bong;Kang, Chu-Shik
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.9
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    • pp.60-67
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    • 2007
  • A signal conditioning circuit for capacitive displacement sensors was developed using a high frequency modulation/demodulation method, and its performance was evaluated. Since capacitive displacement sensors can achieve high resolution and linearity, they have been widely used as precision sensors within the range of several hundred micrometers. However, they inherently have a limitation in low frequency range and some nonlinearity characteristics and so a specially designed signal conditioning circuit is needed to handle these properties. The developed signal processing circuit consists of three parts: linearization, modulation/demodulation, and nonlinearity compensation. Each part was constructed discretely using several IC chips and passive elements. An evaluation system for precision displacement sensors was developed using a laser interferometer, a precision stage, and a PID position controller. The signal processing circuit was tested using the evaluation system in the respect of resolution, repeatability, linearity, and so on. From the experimental results, we know that a highly linear voltage output can be obtained successfully, which is proportional to displacement and the nonlinearity of output is less than 0.02% of full range. However, in the future, further investigation is required to reduce noise level and phase delay due to a low-pass filter. The evaluation system also can be applied effectively to calibration and evaluation of precision sensors and stages.

Crosstalk analysis of laser-diode array modules for wavelength division multiplexing (파장 분할 다중화 방식을 위한 고속 레이저 다이오드 배열 모듈의 혼신해석)

  • 김성일;이해영
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.7
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    • pp.71-78
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    • 1997
  • In this paper, we analyzed the crosstalk characteristics of LD array modules for WDM and improved the crosstalk levels using a screening line between access lines. From the calculation resutls, we have found that inductive crosstalk of access lines is dominant for the low impedance LD arrays with short bondwire interconnections. The proposed array interconnecton with the screening line and ouble bondwires, rduces the crosstalk level about 10dB compared to conventional interconnections using simple access lines and a single bondwire. This proposed structure also can be easily imlemented with transmission reliability.

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Vibration Analysis Using Laser Speckle (레이저 스펙클을 이용한 진동분석)

  • Ruck, Do-Jin;Sung, Duk-Yong;Kang, Sung-Soo;Lee, Won-Jin
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.2
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    • pp.77-80
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    • 2001
  • The purpose of this work is that by using speckle phenomena of low-level He-Ne laser, it analyzes the movement condition of surface elements on a substance vibrating. The lights from laser reflect against a copper plate and will be shown as speckles on a vibration board. If we vibrate these speckles by sound waves of a speaker installed on the back, the speckles change with various shapes. When a vibration board has a maximum vibration, the frequency becomes a dynamical resonance frequency and we can mark the changes of speckles at that time on a vibration board.

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