• Title/Summary/Keyword: laser intensity

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Detection of Mitochondrial Reactive Oxygen Species in Living Rat Trigeminal Caudal Neurons

  • Lee, Hae In;Chun, Sang Woo
    • International Journal of Oral Biology
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    • v.40 no.2
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    • pp.103-109
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    • 2015
  • Growing evidence suggests that mitochondrial reactive oxygen species (ROS) are involved in various pain states. This study was performed to investigate whether ROS-induced changes in neuronal excitability in trigeminal subnucleus caudalis are related to ROS generation in mitochondria. Confocal scanning laser microscopy was used to measure ROS-induced fluorescence intensity in live rat trigeminal caudalis slices. The ROS level increased during the perfusion of malate, a mitochondrial substrate, after loading of 2',7'-dichlorofluorescin diacetate ($H_2DCF-DA$), an indicator of the intracellular ROS; the ROS level recovered to the control condition after washout. When pre-treated with phenyl N-tert-butylnitrone (PBN) and 4-hydroxy-2,2,6,6-tetramethylpiperidene-1-oxyl (TEMPOL), malate-induced increase of ROS level was suppressed. To identify the direct relation between elevated ROS levels and mitochondria, we applied the malate after double-loading of $H_2DCF-DA$ and chloromethyl-X-rosamine (CMXRos; MitoTracker Red), which is a mitochondria-specific fluorescent probe. As a result, increase of both intracellular ROS and mitochondrial ROS were observed simultaneously. This study demonstrated that elevated ROS in trigeminal subnucleus caudalis neuron can be induced through mitochondrial-ROS pathway, primarily by the leakage of ROS from the mitochondrial electron transport chain.

High-Energy Proton Generation with High Energy Conversion Efficiency Driven by Ultrashort High-Intensity Ti:Sapphire Laser (극초단 고출력 티타늄 사파이어 레이저에 의한 높은 에너지 변환효율을 가지는 고에너지 양성자 발생)

  • Choe, Il-U;Yu, Tae-Jun;Seong, Jae-Hui;Kim, Hyeong-Taek;Jeong, Tae-Mun;Hong, Gyeong-Han;Kim, Jeong-Hun;No, Yeong-Cheol;Go, Do-Gyeong;Lee, Jong-Min;Sagisaka, Akito;Yogo, Akifumi;Orimo, Satoshi;Ogura, Koichi;Li, Zhong;Pirozhkov, Alexander;Daido, Hiroyuki;Oishi, Yuji;Nemoto, Koshichi;Nakamura, Shyu;Noda, Akira;Iwashita, Yoshihisa;Shirai, Toshiyuki
    • Proceedings of the Optical Society of Korea Conference
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    • 2006.07a
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    • pp.379-380
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    • 2006
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Development of a Robotic System for Measuring Hole Displacement Using Contact-Type Displacement Sensors (접촉식 변위센서를 이용한 홀 변위 측정 로봇시스템 개발)

  • Kang, Hee-Jun;Kweon, Min-Ho;Suh, Young-Soo;Ro, Young-Shick
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.1
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    • pp.79-84
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    • 2008
  • For the precision measurement of industrial products, the location of holes inside the products, if they exist, are often selected as feature points. The measurement of hole location would be performed by vision and laser-vision sensor. However, the usage of those sensors is limited in case of big change of light intensity and reflective shiny surface of the products. In order to overcome the difficulties, we have developed a hole displacement measuring device using contact-type displacement sensors (LVDTs). The developed measurement device attached to a robot measures small displacement of a hole by allowing its X-Y movement due to the contact forces between the hole and its own circular cone. The developed device consists of three plates which are connected in series for its own function. The first plate is used for the attachment to an industrial robot with ball-bush joints and springs. The second and third plates allow X-Y direction as LM guides. The bottom of the third plate is designed that various circular cones can be easily attached according to the shape of the hole. The developed system was implemented for its effectiveness that its measurement accuracy is less than 0.05mm.

2-Dimensional Holographic Grating Formation in Chalcogenide Thin Films

  • Lee, Jung-Tae;Yeo, Choel-Ho;Chung, Hong-Bay
    • Transactions on Electrical and Electronic Materials
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    • v.5 no.1
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    • pp.34-37
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    • 2004
  • Amorphous chalcogenide thin films, especially a-(Se, S) based films, exhibit a number of photo-induced phenomena. In this study, we make the As$\_$40/Ge$\_$10/Se$\_$15/S$\_$35//Ag thin film and then we measure the holographic diffraction efficiency according to thickness of Ag. And we form the two-dimensional holographic grating. At first, we formed one-dimensional grating and then we form two-dimensional grating by rotate the sample. We found out the most suitable thickness of Ag and in case of As$\_$40/Ge$\_$10/Se$\_$15/S$\_$35//Ag(600${\AA}$), the diffraction efficiency was more higher than other samples. The holographic grating was formed by He-Ne laser(λ=632.8nm). The intensity of incident beam was 2.5mW and incident angle was 20$^{\circ}$. We confirm. the two-dimensional holographic grating by the pattern of diffracted beam and AFM(Atomic Force Microscope) image. We perform the etching process using by 0.26N NaOH in order to confirm clearly two-dimensional grating.

Characteristics of the Photoinduced Anisotropy(PA) in Ag/AsGeSeS Multilayer Thin Films (Ag/AsGeSeS 다층박막의 광유기 이방성(PA) 특성)

  • Yeo, Cheol-Ho;Na, Su-Woong;Shin, Kyung;Park, Jeong-Il;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.2
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    • pp.144-150
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    • 2003
  • The chalcogenide glasses of thin films have the superior property of photoinduced anisotrophy(PA). In this study, we observed the linear dichroism using the irradiation with Polarized He-Ne laser light in the Ag/As$_{40}$ Ge$_{10}$Se$_{15}$ S$_{35}$ multi-layer. Multilayer structures were formed by alternating metal(Ag) and chalcogenide(As$_{40}$ Ge$_{10}$Se$_{15}$ S$_{35}$) thin film. The Ag Polarized photodoping result in reducing the time of saturation anisotropy and increasing the sensitivity of linearly anisotropy intensity As the results, the Ag polarized photodoping will be have a capability of new method that suggests more improvement of photoinduced anisotropy property in the thin films of chalcogenide.ogenide.ide.

The characteristics of holographic diffraction efficiency depend on thickness of Ag in AsGeSeS/Ag thin film (AsGeSeS/Ag 박막에서 Ag의 두께에 따른 홀로그래픽 회절 효율 특성)

  • Lee, Jung-Tae;Lee, Ki-Nam;Yeo, Cheol-Ho;Lee, Yeong-Jong;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.490-493
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    • 2003
  • We have carried out two-beam interference experiment to form holographic grating on amorphous $As_{40}Ge_{10}Se_{15}S_{35}/Ag$ double-layer. In this study holographic grating formed using He-Ne laser(632.8nm) under non-polarization state and p-polarization state and we confirm that the diffraction efficiency depend on thickness of Ag. The diffraction efficiency was obtained by first order intensity. We got the maximum diffraction efficiency that thickness of Ag was $600{\AA}$. The maximum diffraction efficiency was 13.5% in (P:P) polarization state.

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Violet Photoluminescence Emitted from Al-doped ZnO Thin Films (Al 도핑된 ZnO 박막에서 방출되는 보라색 발광 스펙트럼)

  • Hwang, Dong-Hyun;Son, Young-Guk;Cho, Shin-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.4
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    • pp.318-324
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    • 2007
  • We report on a strong violet luminescence emitted from the ZnO:Al films grown on glass substrate by radio-frequency magnetron sputtering. The growth of high-quality thin films and their optical properties are controlled by adjusting the mixture ratio of Ar and $O_2$, which is used as the sputtering gas. The crystallinity of the films is improved as the oxygen flow ratio is decreased, as evidenced in both x-ray diffractometer and atomic force microscope measurements. As for the violet luminescence measured by photoluminescence (PL) spectroscopy, the peak energy and intensity of the PL signal are decreased with increasing the oxygen flow ratio. The peak energy of the violet PL spectrum for the thin film with an oxygen flow ratio of 50 % is almost constant, regardless of the increase of laser Power and temperature. These results indicate that the violet PL signal is probably due to defects related to interstitial Zn atoms.

Construction of an Optically Pumped Cesium Atomic Clock (광펌핑 세슘원자시계의 구성)

  • 이호성;오차환;양성훈
    • Korean Journal of Optics and Photonics
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    • v.3 no.2
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    • pp.123-132
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    • 1992
  • We designed and constructed the Cs beam tube which consists of a Ramsey cavity, four C-field rods, fluorescence detecting systems, and etc. for developing an optically pumped Cs atomic clock. A semiconductor laser was used for optical pumping and probing in the Cs beam. We observed Ramsey resonance signal by detecting the fluorescence signal in the probing region as the microwave frequency injected into the Ramsey cavity was scanned near 9192.6 MHz which corresponds to the "clock transition" of Cs atoms. We found that the linewidth of the Ramsey signal was 200 Hz, the magnetic field intensity was $8.61\muT$ when the current of 0.8A flowed in the C-field rods, and the second order Zeeman shift by the magnetic field was 3.17 Hz.s 3.17 Hz.

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Flow Characteristics of a Gas-Liquid Slug Flow in Small Vertical Tubes (작은 수직관을 흐르는 기-액 슬러그 유동의 유동특성)

  • Kye, Seok-Hyun;Kim, Dong-Seon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.5
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    • pp.246-254
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    • 2013
  • Some characteristics of nitrogen-water slug flow were optically measured, in vertical acrylic tubes of 2, 5 and 8 mm diameter. Bubble velocity, bubble and unit cell lengths were measured, by analyzing the light intensity signals from two sets of dot laser-infrared sensor modules mounted along the transparent tubes. Optical images of the bubbles were also taken and analyzed, to measure bubble shapes and liquid film thickness. It was found that the measured bubble velocities were in good agreement with the empirical models in the literature, except for those measured under high superficial velocity condition in the 2 mm tube. Bubble length was found to be the longest in the 2 mm tube, being 4 to 5 times those of the other tubes. Liquid film was found to have developed early in the 2 mm tube, which made the blunt shape of the bubble head. Liquid film thickness in the 8 mm tube was measured at almost twice those of the other tubes.

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.