• Title/Summary/Keyword: LED fluorescence

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Photochemical Index Analysis on the Influence of LED Illumination Color Temperature on Donarium Cherry (도시야간조명의 LED 색온도별 겹벚나무의 광화학적 생리지표 해석)

  • Kim, Ji-Su;Yoo, Sung-Yung;Kim, Hway-Suh;Kim, Tae-Wan
    • Korean Journal of Environmental Biology
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    • v.36 no.2
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    • pp.117-123
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    • 2018
  • In this study, the efficiency of photosynthetic electron transfer according to LED color temperature was verified in order to find a way to efficiently grow trees under night illumination. The experiment was carried out with White treatment, Warmwhite treatment, and non-treatment with donarium cherry. The study uses to a method for analyzing and evaluating the color temperature of an LED light source by photochemical analysis. We found that all treatments 115 DAT of maximum fluorescence amount(P) had the lowest. In the treatment using white light and the Warm-white light, the T amount of florescence of the late stage during the transition of the J-I level was increased, and the photosystem I electron transfer efficiency was decreased. Therefore, the electron transport efficiency of $RE1_O/CS$ and RE1o/RC were reduced. Especially, compared to Warmwhite, the light intensity increased greatly in the white-light treatment, The $PI_{TOTALABS}$ of 7 DAT was the highest value, but it was decreased to the lowest value on 115 DAT. This study has shown that the white treatment was low in electron transfer efficiency and soundness. Warmwhite-light treatments showed lower stress.

Aequorin Based Functional Assessment of the Melanin Concentrating Hormone Receptor by Intracellular Calcium Mobilization

  • Lee, Sung-Hou
    • Biomolecules & Therapeutics
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    • v.18 no.2
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    • pp.152-158
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    • 2010
  • Melanin concentrating hormone is a neuropeptide highly expressed in the brain that regulates several physiological functions mediated by receptors in the G-protein coupled receptor family, especially plays an important role in the complex regulation of energy balance and body weight mediated by the melanin concentrating hormone receptor subtype 1 (MCH1). Compelling pharmacological evidence implicating MCH1 signaling in the regulation of food intake and energy expenditure has generated a great deal of interest by pharmaceutical companies as MCH1 antagonists may have potential therapeutic benefit in the treatment of obesity and metabolic syndrome. Although fluorescence-based calcium mobilization assay platform has been one of the most widely accepted tools for receptor research and drug discovery, fluorescence interference and shallow assay window limit their application in high throughput screening and have led to a growing interest in alternative, luminescence-based technologies. Herein, a luminescence-based functional assay system for the MCH1 receptor was developed and validated with the mitochondrial targeted aequorin. Aequorin based functional assay system for MCH1 presented excellent Z' factor (0.8983) and high signal-to-noise ratio (141.9). The nonpeptide MCH1 receptor antagonist, SNAP 7941 and GSK 803430, exhibited $IC_{50}$ values of 0.62 ${\pm}$ 0.11 and 12.29 ${\pm}$ 2.31 nM with excellent correlation coefficient. These results suggest that the aequorin based assay system for MCH1 is a strong alternative to the traditional GPCR related tools such as radioligand binding experiments and fluorescence functional determinations for the compound screening and receptor research.

Fluorescence-Quenched Sensor for Trinitophenol in Aqueous Solution Based on Sulfur Doped Graphitic Carbon Nitride

  • Min, Kyeong Su;Manivannan, Ramalingam;Satheshkumar, Angu;Son, Young-A
    • Textile Coloration and Finishing
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    • v.30 no.2
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    • pp.63-69
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    • 2018
  • In this study, we report on successful attempt towards the synthesis of sulfur self-doped $g-C_3N_4$ by directly heating thiourea in air. The synthesized materials were characterized using UV-vis spectral technique, FT-IR, XRD and TEM analysis. Further, the obtained material shows an excellent detection of carcinogenic TNP(Tri nitro phenol) in the presence of 10-fold excess of various other common interferences. The strong inner filter effect and molecular interactions(electrostatic, ${\pi}-{\pi}$, and hydrogen bonding interactions) between TNP and the $S-g-C_3N_4$ Nano sheets led to the fluorescence quenching of the $S-g-C_3N_4$ Nano sheets with an excellent selectivity and sensitivity towards TNP compared to that of other nitro aromatics under optimal conditions and the detection limit calculated was found to be 6.324 nM for TNP. The synthesized nanocomposite provides a promising platform for the development of sensors with improved reproducibility and stability for ultra-sensitive and selective sensing of TNP.

The Determination of Rare Earth Oxides by X-Ray Fluorescence Spectrometry Using Empirical Coefficient Method (실험계수법을 이용한 희토류산화물의 X-선 형광분광분석)

  • Young Man Kim;Beom Suk Choi;Sun Tae Kim;Chong Wook Lee
    • Journal of the Korean Chemical Society
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    • v.31 no.1
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    • pp.64-70
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    • 1987
  • Rare earth elements including Y and Th in the monazite were separated and determined by X-ray fluorescence spectrometry. The matrix effects among the rare earth elements were simultaneously corrected by means of empirical coefficient method. The values of the coefficients were quite dependent on the number of the standards. However, the different set of coefficients led to the same results. The analytical results corrected by the present method agreed with those by the inductively coupled plasma spectrometry.

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Comparison of Enhancing Fingerprints Treated with Two Fluorescence Amino Acid Reactive Reagents in Accordance with Laser and LED Light Sources (광원에 따른 아미노산 반응 형광시약 처리지문의 증강 효과성 비교)

  • Kim, Chae-Won;Ki, Jin-Young;Kim, Kyu-Yeon;Kim, Ji-Yeon;Jeon, So-Young;Yu, Je-Seol
    • The Journal of the Korea Contents Association
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    • v.17 no.4
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    • pp.569-575
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    • 2017
  • Forensic light source is commonly used for enhancing evidence in a nondestructive way. Latent fingerprints play an important role in an aspect of crime scene investigation. In this study, researchers compared enhancement of standard fingerprints treated with DFO and 1,2-IND in accordance with laser and LED light sources. As a result, laser light source has a better effect rather than LED light sources. However, each light source has strengths and weaknesses in terms of performance and portability. Therefore, researchers recommend that crime scene investigators need to use laser and LED light sources depending on the situation.

Growth and Phytochemical Contents of Ice Plant as Affected by Light Quality in a Closed-type Plant Production System (완전제어형 식물생산시스템에서 광질에 따른 아이스플랜트의 생육과 기능성물질 함량)

  • Kim, Young Jin;Kim, Hye Min;Hwang, Seung Jae
    • Horticultural Science & Technology
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    • v.34 no.6
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    • pp.878-885
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    • 2016
  • A study was conducted to examine the effects of light quality on the growth and phytochemical contents of ice plant in a closed-type plant production system. Seeds were sown in a 128-cell plug tray using rockwool. The seedlings were then transplanted into a deep floating technique system with recirculating nutrient solution (EC $1.5dS{\cdot}m^{-1}$, pH 6.5) in a closed-type plant production system. The nutrient solution was supplied at two weeks after transplanting with 2.0 mM NaCl concentration in all treatments for the development of the bladder cells. The three light sources with different light qualities used were as followed; FL (fluorescent lamps), combined RW LED (red:white = 7:3), and combined RBW LED (red:blue:white = 8:1:1) at $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD with a photoperiod of 14/10 hours (light/dark). The results showed that the FL treatment had the greatest growth enhancement effects on the leaf area and the fresh and dry weights of the shoots and roots. The SPAD values were significantly higher under the FL and RBW LED treatments, at 29.8 and 30.6, respectively. No significant difference was observed in salinity under all treatments. Chlorophyll fluorescence was significantly higher under the FL treatment. The total phenol content and antioxidant activity were the highest under the RBW LED treatment. The total flavonoid content was significantly higher under the RBW LED and FL treatments. Hence, the results indicate that the growth of ice plant was maximized under the FL treatment. The phytochemical contents were maximized under the RBW LED treatment.

Evaluation of Particle Counting by Smartphone-based Fluorescence Smartscope and Particle Positioning in Spinning Helical Channel (스마트폰 기반 형광 smartscope의 입자계수 및 회전하는 나선형 채널의 입자정렬 성능 평가)

  • Park, Eunjung;Kim, Subin;Cho, Myoung-Ock;Kim, Kyunghoon;Shourav, Mohiuddin Khan;Kim, Sunwook;Lee, Jeonghoon;Kim, Jung Kyung
    • Journal of Korea Society of Industrial Information Systems
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    • v.20 no.3
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    • pp.19-28
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    • 2015
  • With the aim of developing a smartphone-based point-of-care device that is small, inexpensive, and easy to handle by non-expert, we designed a fluorescence smartscope for counting particles and a DC motor-controlled particle positioning system. Our smartscope can count the number of fluorescent particles and fluorescently-stained white blood cells through a phone camera with an adaptor containing a LED, a ball lens and optical filters and an application running on a smartphone. The motor was controlled wirelessly via Bluetooth with an Android smartphone. We found that axial spinning of a helical microfluidic channel allows arrangement of particles having size similar to the white blood cells. The motor-controlled particle positioning system can minimize time-consuming manual processes and automate sample preparation process and thus, if integrated with the smartscope, it can be used for a point-of-care testing device based on a smartphone.

A Study on PWM Control of Near-Infrared Fluorescence Imaging System (근적외선 형광 영상시스템의 PWM 제어에 관한 연구)

  • Lee, Byeong-Ho;Pan, Sung Bum
    • The Journal of Korean Institute of Information Technology
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    • v.16 no.11
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    • pp.115-121
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    • 2018
  • Fluorescent images using near-infrared light have no worry about radioactivity, and images can be checked in real time during surgery. Therefore experiments using fluorescent images for monitoring lymph node biopsy are actively under way. Fluorescent imaging equipment uses high heat-generating components such as LED and camera, thus uses water-cooling system as a stable heating suppression means. However in the fluorescent image equipment, the water cooling system takes a large volume which is a disadvantage in terms of miniaturization of the equipment. Even if the air cooling system is used for miniaturizing the equipment, heat generation is a problem. In this paper, we have experimented with the air cooling method using PWM control for the miniaturization of the equipment, and confirmed the constant quality of the fluorescent image and the suppression of the heat generation without any problems even when the equipment is used for a long time.

Chlorophyll Fluorescence, Chlorophyll Content, Graft-taking, and Growth of Grafted Cucumber Seedlings Affected by Photosynthetic Photon Flux of LED Lamps (LED 램프의 광합성유효광양자속이 오이접목묘의 엽록소형광, 엽록소함량, 활착 및 생장에 미치는 영향)

  • Kim, Hyeong Gon;Lee, Jae Su;Kim, Yong Hyeon
    • Journal of Bio-Environment Control
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    • v.27 no.3
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    • pp.231-238
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    • 2018
  • Chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings as affected by photosynthetic photon flux (PPF) of LED lamps were analyzed in this study. Four PPF levels, namely 25, 50, 100, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ were provided to investigate the effect of light intensity on the chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings. Air temperature, relative humidity, and photoperiod for graft-taking were maintained at $25^{\circ}C$, 90%, $16h{\cdot}d^{-1}$, respectively. Maximum quantum yield (Fv/Fm) of rootstock as affected by PPF was found to be 0.84-0.85 and there was no significant change in Fv/Fm. Even though Fv/Fm of scion measured at 2 days after grafting was lowered to 0.81-0.82, after then it gradually increased with increasing PPF. At 4 days after grafting, the chlorophyll content extracted from scion increased with increasing PPF. Graft-taking ratio of grafted cucumber seedlings was 90-95% as PPF was ranged from $25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ to $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. However, the graft-taking ratio of grafted seedlings healed under PPF of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was decreased to 80%. Maximum PPF measured required for smooth joining of rootstock and scion was assumed to be $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. At healing stage of grafted cucumber seedlings, Fv/Fm of scion decreased and at least two days after grafting were required for rooting of grafted seedlings. Chlorophyll fluorescence response of rootstock and scion was linked to light irradiation. Therefore, it was concluded that physical environment including light and humidity during healing process of grafted seedlings should be controlled more precisely to facilitate root formation and to prevent scion from lowering Fv/Fm. Further studies are required to investigate the effects of root development and joining of vascular bundles of grafted seedlings on the chlorophyll content of scion.

Dynamic Behaviors of Redox Mediators within the Hydrophobic Layers as an Important Factor for Effective Microbial Fuel Cell Operation

  • Choi, Young-Jin;Kim, Nam-Joon;Kim, Sung-Hyun;Jung, Seun-Ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.4
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    • pp.437-440
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    • 2003
  • In a mediator-aided microbial fuel cell, the choice of a proper mediator is one of the most important factors for the development of a better fuel cell system as it transfers electrons from bacteria to the electrode. The electrochemical behaviors within the lipid layer of two representative mediators, thionin and safranine O both of which exhibit reversible electron transfer reactions, were compared with the fuel cell efficiency. Thionin was found to be much more effective than safranine O though it has lower negative formal potential. Cyclic voltammetric and fluorescence spectroscopic analyses indicated that both mediators easily penetrated the lipid layer to pick up the electrons produced inside bacteria. While thionin could pass through the lipid layer, the gradual accumulation of safranine O was observed within the layer. This restricted dynamic behavior of safranine O led to the poor fuel cell operation despite its good negative formal potential.