• Title/Summary/Keyword: Fluorescent intensity

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A Quinoline-thiooxorhodamine Conjugate for Fluorescent Hg2+ Recognition in Aqueous Media and Living Cells

  • Tang, Lijun;Wen, Xin;Dai, Xin;Wu, Di;Huang, Zhenlong
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3326-3330
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    • 2014
  • A quinoline-thiooxorhodamine conjugate fluorescent sensor (1) has been synthesized. Sensor 1 exhibits high selectivity and sensitivity to $Hg^{2+}$ in $H_2O$/DMSO (95/5, v/v, HEPES 20 mM, pH = 7.4) solution with fluorescence detection. Other tested metal ions do not induce any significant fluorescence intensity changes. Sensor 1 interacts with $Hg^{2+}$ through a 1:1 binding stoichiometry with a good anti-inference ability. In addition, fluorescent imaging of $Hg^{2+}$ in Hela cells is also successfully demonstrated.

The distribution of the molecular hydrogen in the Milky way

  • Jo, Young-Soo;Seon, Kwang-Il;Min, Kyoung-wook
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.40.1-40.1
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    • 2016
  • We present the far-ultraviolet fluorescent molecular hydrogen ($H_2$) emission map observed with FIMS/SPEAR for ~76% of the sky. The fluorescent $H_2$ emission is found to be saturated by strong dust extinction at the optically thick, Galactic plane region. However, the extinction-corrected intensity of fluorescent $H_2$ emission is found to have strong linear correlations with the well-known tracers of the cold interstellar medium, such as the E(B-V) color excess, neutral hydrogen column density N(HI), $H{\alpha}$ emission, and CO $J=1{\rightarrow}0$ emission. The all-sky molecular hydrogen column density map is also obtained using a photodissociation region model. We also derive the gas-to-dust ratio, hydrogen molecular fraction ($f_{H2}$), and $CO-to-H_2$ conversion factor ($X_{CO}$) of the diffuse interstellar medium. The gas-to-dust ratio is consistent with the standard value $5.8{\times}10^{21}atoms\;cm^{-2}mag^{-1}$, and the $X_{CO}$ tends to increase with E(B-V), but converges to the Galactic mean value $1.8{\times}10^{20}cm^{-2}K^{-1}km^{-1}s$ at optically thick regions with E(B-V)>2.0.

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Characteristics of chain-forming cells in Gyrodinium impudicum using fluorescent ConA

  • Park, Eun-Ju;Kim, Gwang-Hoon;Cho, Yong-Chul;Cho, Eun-Seob
    • Journal of the korean society of oceanography
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    • v.34 no.4
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    • pp.214-219
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    • 1999
  • Cells of the dinoflagellate Gyrodinium impudicum form characteristic chains, which are associated with sugar accumulated on the cell surface. To resolve the relationship between chain-formation and cell surface sugar accumulation, confocal microscopy was used to observe sugar accumulation points in the vegetative cells and long chain-forming cells of G. impudicum cells treated with fluorescent-tagged ConA. In the stationary and exponential phases, both vegetative cells and chain-forming cells were similar to each other in fluorescent intensity. There was no evidence that chain-forming cells had a specific location for sugar accumulation on the cell surface. Most of the cells formed 2-cell chains one day after inoculation, but longer chains consisting of 4-8 cells increased markedly in 4day and 8 day cultures. Gyrodinium impudicum chains usually consist of more than four cells, and chains of 8 or even 16 cells can be observed in mature cultures. Temperature played an importantrole in chain-formation of the cells, threshold temperature for the development of long chain-formation was 19 $^{\circ}$C.

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Specific Detection of DNA Using Quantum Dots and Magnetic Beads for Large Volume Samples

  • Kim, Yeon-Seok;Kim, Byoung-Chan;Lee, Jin-Hyung;Kim, Jung-Bae;Gu, Man-Bock
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.5
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    • pp.449-454
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    • 2006
  • Here we present a sensitive DNA detection protocol using quantum dots (QDs) and magnetic beads (MBs) for large volume samples. In this study, QDs, conjugated with streptavidin, were used to produce fluorescent signals while magnetic beads (MBs) were used to isolate and concentrate the signals. The presence of target DNAs leads to the sandwich hybridization between the functionalized QDs, the target DNAs and the MBs. In fact, the QDs-MBs complex, which is bound using the target DNA, can be isolated and then concentrated. The binding of the QDs to the surface of the MBs was confirmed by confocal microscopy and Cd elemental analysis. It was found that the fluorescent intensity was proportional to concentration of the target DNA, while the presence of non-complementary DNA produced no significant fluorescent signal. In addition, the presence of low copies of target DNAs such as 0.5 pM in large volume samples up to 40mL was successfully detected by using a magnet-assisted concentration protocol which consequently results in the enhancement of the sensitivity more than 100-fold.

Protein Cyclization Enhanced Thermostability and Exopeptidase-Resistance of Green Fluorescent Protein

  • Zhao, Zhonglin;Ma, Xin;Li, Liang;Zhang, Wei;Ping, Shuzhen;Xu, Ming-Qun;Lin, Min
    • Journal of Microbiology and Biotechnology
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    • v.20 no.3
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    • pp.460-466
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    • 2010
  • A mutant of green fluorescent protein ($GFPmut3^*$) from the jellyfish Aequorea victoria was cyclized in vitro and in vivo by the use of a naturally split intein from the dnaE gene of Synechocystis species PCC6803 (Ssp). Cyclization of $GFPmut3^*$ was confirmed by amino acid sequencing and resulted in an increased electrophoretic mobility compared with the linear $GFPmut3^*$. The circular $GFPmut3^*$ was $5^{\circ}C$ more thermostable than the linear form and significantly more resistant to proteolysis of exopeptidase. The circular $GFPmut3^*$ also displayed increased relative fluorescence intensity. In addition, chemical stability of $GFPmut3^*$ against GdnHCl revealed more stability of the circular form compared with the linear form.

Spectrofluorimetric determination of free cyanide ion with fluorescent safranine-O (형광시약 Safranine-O를 이용한 유리 시안화 이온의 분광형광법 정량)

  • Choi, Hee-Seon
    • Analytical Science and Technology
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    • v.25 no.3
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    • pp.159-163
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    • 2012
  • A spectrofluorimetric method has been developed for the determination of free $CN^-$ in real samples with fluorescent safranine-O. When safranine-O interacts electrostatistically with $CN^-$, the fluorescent intensity of safranine-O is decreased. Several experimental conditions such as pH of the sample solution and the amount of safranine-O were optimized. $Ag^+$ interfered higher than any other ions. Interference of $Ag^+$ could be disregarded because $Ag^+$ was scarcely contained or mostly complexed with $CN^-$ in selected real samples. With this proposed method, the linear range of $CN^-$ was from 5.0 to 110 ng/mL and the detection limit of $CN^-$ was 2.9 ng/mL. For validating this technique, real samples (Cu, Ag, Au electroplating wastewater, and untreated wastewater in university and in sewage treatment plant) were used. Recovery yields of 91.5%~106.0% were obtained. Based on experimental results, it is proposed that this technique can be applied to the practical determination of free $CN^-$.

Laser Diagnostics of Spray and Combustion Characteristics Using Multi-Component Mixed Fuels in a D.I. Diesel Engine (다성분 혼합연료를 이용한 디젤 분무 및 연소특성의 광계측 진단)

  • Yoon, Jun-Kyu;Myong, Kwang-Jae;Senda, Jiro;Fujimoto, Hajime;Cha, Kyung-Ok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.5
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    • pp.172-180
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    • 2006
  • This study was to analyze the effect of mixed fuel composition and mass fraction on the characteristics of evaporating diesel spray and combustion under the various ambient conditions. The characteristics of vaporization distribution and combustion were visualized by laser induced fluorescent method and direct photography. The experiments were conducted in the constant volume vessel and rapid compression expansion machine with optical access. Multi-component fuels mixed i-octane, n-dodecane and n-hexadecane were injected the vessel and rapid compression expansion machine with electronically controlled common rail injector. Experimental results show that fuel vapor formed stratified distribution. And vaporization and diffusion are become actively increasing in mass fraction of low boiling point component. Consequently multi-component fuels were expected to control the evaporating behavior according to their suitable mass fraction.

Effects of Erythrosine on the Cholesterol Oxidative Stability in an Aqueous Model System (수용성 모형계에서 콜레스테롤의 산화 안정성에 대한 Erythrosine의 영향)

  • Chung, Man-Gon;Kim, Jong-Seung;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
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    • v.28 no.1
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    • pp.197-202
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    • 1996
  • The effects of erythrosine on the oxidative stability of cholesterol in an aqueous model system were studied by depleted headspace oxygen and cholesterol oxidation products (COP). As the oncentration of erythrosine was increased, headspace oxygen depletion, 7-COP and total COP increased during storage at $25^{\circ}C$ for 50 hours under the fluorescent light. As the intensity of fluorescent light was increased, amounts of headspace oxygen depleted and COP formed in an aqueous cholesterol dispersion containing erythrosine also increased. Addition of ${\alpha}-,\;{\delta}-$, mixed-tocopherol and ${\beta}-carotene$ resulted in the enhanced oxidative stability of an aqueous cholesterol dispersion containing erythrosine during the fluorescent light storage.

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Growth and Flowering before and after Storage of African Marigold and Salvia Seedlings Stored under Different Light Conditions

  • Heo, Jeong Wook;Kim, Dong Eok;Kang, Kee Kyung;Park, Sang Hee;Chun, Changhoo
    • Horticultural Science & Technology
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    • v.31 no.4
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    • pp.400-406
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    • 2013
  • This study was conducted to investigate the growth and flowering of African marigold (Tagetes erecta L.) and salvia (Salvia splendens F. Sello ex Ruem & Schult.) seedlings before and after storage under fluorescent lamps and green LED radiation conditions with different light intensities during storage. The both seedlings were kept under a storage room controlled at $8^{\circ}C$ air temperature and $40{\pm}10%$ relative humidity conditions. Light intensities were maintained at 15 and $30{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ during storage. In lighting treatments, dry weight of African marigold at 28 days after storage was not significantly different, and decreased approximately 29% compared to pre-storage under dark treatment. There was no significant difference in the leaf area of salvia seedlings stored under dark condition compared to before storage, but the leaf area under green light radiation with higher light intensity (treatment GH) was two times greater than before storage. The survival rate after transplanting of African marigold stored under dark condition was 10%, and days to flowering increased compared to those stored under fluorescent and green light with higher light intensity (treatment FLH, GH). Comparing to before storage, growth and flowering of the both seedlings after storage were significantly promoted by the light exposure during storage. The present experimental results show that the light intensity should be decided to maintain minimum growth during lighting storage and storage quality of the seedlings such as flowering promotion and extended blooming period after lighting treatment during storage period from the above results.

The Color Enhancement of TV Picture by the Color Measurement of Illumination (광원의 색채 계측에 의한 TV 화상의 색 향상)

  • 이응주;정인갑;박양우;이광춘;하영호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.1
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    • pp.47-58
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    • 1996
  • An object color can be seen differently under the various outer illuminants. However, human visual system has color constnacy that the object color can be seen constantly under the different outer illuminants. When the viewer watches TV under specific that the object color can be seen constantly under the different outer illuminants. When the viewer bathes TV under specific outer illuminants, he perceives distortes color due to the emitting specturm of outer illuminants as well as the radiation of CPT itself. Namely, when the outer illuminants such as fluorescent and incandescent lamps incident on CPT, brightness, saturation, hue, itself. Namely, when the outer iluminants such as fluorescent and incandescent lamps incident on CPT, brightness, saturation, hue, and contrast on color pictures are changend, he perceives distortedcolr fromthe original color. In this paper color enhancement algorithm based on light intensity and outer light decision funtion using RGB sensor was proposed. The implemented TV of proposed algorithm has higher visual quality at the view point of human visual system and more vivid than that ofcoventional color TV.

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