• Title/Summary/Keyword: Fluorometric

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A Study on the Measurements of Optical Parameters in Photosensitizer by Light Scattering (농도가 진한 매질에서 광증감제에 의한 광학적 파라미터측정에 관한 연구)

  • Kim, Ki-Jun;Lee, Jou-Joub
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.1
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    • pp.102-108
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    • 2011
  • The study of wave propagation and scattering in biological media has become increasingly important in recent years. The propagation of light within tissues is an important problem that confronts the dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. In the clinical application of photodynamic therapy(PDT) and in photobiology, the photon deposition within a tissue determines the spatial distribution of photochemical reactions. Scattered light is measured as a function of the distance (r) between the axis of the incident beam and the detection spot. Consequently, knowledge of the photosensitizer(Chlorophyll-a) function that characterizes a phantom is measured. To obtain the results of scattering coefficients(${\mu}s$) of a turbid material from diffusion described by experimental approach. It was measured the energy fluency of photon radiation at the position of penetration depth. From fluorescence experimental method obtained the analytical expression for the scattered light as the values of $(I/I_o)_{wavelength}$ vs the distance between the center of the incident beam and optical fiber in terms of the condition of "in situ spectroscopy(optically thick)" and real time by fluorometric measurements. The result was compromised with transport of intensities though a random distribution of scatters.

A Study on the Optical Influence by Photosensitizer in Vitro (In Vitro에서 광증감제에 의한 광학적 영향에 관한 연구)

  • Kim, Ki-Jun;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.2
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    • pp.182-190
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    • 2005
  • The propagation of light radiation within tissues is an important problem that confronts the dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. In the clinical application of photodynamic therapy(PDT) and in photobiology, the photon deposition within a tissue determines the spatial distribution of photochemical reactions. Scattered light is measured as a function of the distance (r) between the axis of the incident beam and the detection spot. Consequently, knowledge of the photosensitizer(Chlorophyll-a) function that characterizes a phantom is important. To obtain the results of scattering coefficients(${\mu}s$) of a turbid material from diffusion described by experimental approach. It was measured the energy fluency of photon radiation at the position of penetration depth. From fluorescence experimental method obtained the analytical expression for the scattered light as the values of $(I\;/I_o)_{wavelength}$ vs the distance between the center of the incident beam and optical fiber in terms of the condition of "in situ spectroscopy(optically thick)" and real time by fluorometric measurements.

Paralytic Shellfish Toxins in the Mussel, Mytilus edulis, Caused the Shellfish Poisoning Accident at Geoje, Korea, in 1996 (96년 거제에서 패류 중독 사고를 유발한 진주담치의 마비성 독소)

  • LEE Jong-Soo;SHIN Il-Shik;KIM Young-Man;CHANG Dong-Suck
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.1
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    • pp.158-160
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    • 1997
  • Food poisoning accident occurred on May, 1996 at Oepo, Geoje County, Kyeongnam Province, Korea, and two persons were died within a few hours after ingestion of the soup prepared with wild mussel, Mytilus edulis, harvested on the sea rock. Paralytic shellfish poisons (PSP) were elucidated as the responsible toxins for the food poisons accident because the wild mussels caught after three days at the near place from the accident contained high toxicity of PSP ranged $650\~1000MU/g$ of edible meat by mouse bioassay. Gonyautoxin-1+4 $(42.7\%)$ and C1+C2 $(40.0\%)$ were detected as the major toxins in the mussels by fluorometric HPLC method. Although, the poison extracted out with drip during freezing and thawing, and the toxicity gradually decreased by boiling for 20 minutes, over 30 MU/g of toxins remained in the soup and meat, which indicated that they could be able to make food poisoning.

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Syntheses and Ion Selectivities of Dimeric Rhodamine 6G Chemosensors

  • Chang, Seung Hyun;Choi, Jin-Wook;Chung, Kwang-Bo
    • Journal of Environmental Science International
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    • v.22 no.10
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    • pp.1273-1278
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    • 2013
  • Novel rhodamine 6G fluorescent chemosensors 1 and 2 for the detection of transition metal cations were synthesized through the condensation of rhodamine 6G ethylenediamine with each of 2-hydroxy-1-naphthaldehyde and 2,6-pyridinedicarbaldehyde, respectively. 1 and 2 were characterized using $^{13}C$ NMR, $^1H$ NMR and mass spectroscopy. Fluorometric and colorimetric measurements involving various metal ions revealed the ring opening of the rhodamine 6G spirocycle framework. In the absence of metal cations, 2 was colorless and non-fluorescent, whereas the addition of metal cations ($Hg^{2+}$ and others) changed the color to pink, accompanied by the appearance of an orange fluorescence. The chemosensors exhibited high selectivity for $Hg^{2+}$ over other divalent first-row transition metals. The complexes of $Hg^{2+}$ with 1 and 2 were successfully isolated. A huge enhancement in the fluorescence for both one- and two-photon excitations makes these compounds suitable candidates to be used for fluorescent labeling of biological systems.

Mucolipidosis Type II in Vietnam

  • Vu, Chi Dung
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.2 no.1
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    • pp.31-31
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    • 2016
  • Purpose: To describle clinical features and enzyme activity of Vietnamese patients with Mucolipidosis type II. Methods: Clinical features, laboratory and plasma lysosom enzyme activity by 4 MU-Fluorometric assay was studied from 2014-2015 at the Northern referral center of Pediatrics - National Children's Hospital. Results: 16 cases (7 girls and 9 boys) were diagnosed with I-cell bases on clinical symptoms and enzyme activities studies. Diagnosis age was $5.93{\pm}4.28$ years, onset age was recognised from birth to 4 years (median 1.25) with the feature of joint stiffness and bone deformation. All cases presented with the feature of joint stiffness, chest deformation and kyphoscoliosis; Fifteen cases (93.7%) had coarse facial features. No patients had hepatosplenomegaly on abdominal ultrasound, 5/15 patients had heart valves disease. Enzyme assay showed ${\alpha}$-Hexosaminidase of $1,885.9{\pm}338.7$ (nmol/mg plasma/17 hrs), ${\alpha}$-Iduronate sulfatase of $4,534.8{\pm}1,062.9nmol/mg$ plasma/4 hrs). Conclusion: Mucolipidosis II seriously affected the life of the patients with skeletal deformities, contractures develop in all joints and cardiac involvement.

Detection of Aflatoxins in Soybean Food by HPLC (고속액체 크로마토 그라피에 의한 대두식품중 아플라톡신의 검출)

  • Kim, Young-Kook;Roh, Jung-Koo
    • Korean Journal of Food Science and Technology
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    • v.17 no.4
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    • pp.295-303
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    • 1985
  • Aflatoxin $B_1$, $B_2$, $G_1$, and $G_2$were quantitatively detected by the high pressure liquid chromatography on a Micropak-CN column, with Hexane-THF-IPA-water, using a Lichrosorbpacked flowceil in the fluorometric detector. Under those conditions, the minimum detectable amount of aflatoxin $B_1$ was 0.2 ng. HPLC was used in determining amount of aflatoxins in the commercially manufactured soybean food and home-made Meju. Aflatoxin producing abilities of strains used in the industrially fermented soybean food were also studied with the HPLC technique. Although aflatoxin-like substances were detected in a few samples on TLC, they were not identified with the HPLC retention times of standard aflatoxins. The commercial fungal strains used in Korea had no aflatoxin producing abilities.

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Pigmentation of Claviceps species after on Tryptophan Media (Tryptophan 배지상에서의 Claviceps species에 의한 색소 생합성)

  • Cho, Sung-Hwan;Anderson, John A.
    • Applied Biological Chemistry
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    • v.25 no.3
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    • pp.155-160
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    • 1982
  • Claviceps purpurea PRL 1980 produces a fluorescent reddish brown pigment in the alkaloid production medium. When D,L-tryptophan $[side\;chain-3-^{14}C]$ was administered into the production medium, the radioactive pigment and 5-hydroxytryphan were isolated from the cultures. Conversion of tryptophan to 5-hydroxytryptophan in vivo was shown by an isotopic trapping procedure. 5-hydroxytryptophan isolated from the cultures contained appreciable radioactivity and was recrystallized to constant specific radioactivity. The injection of the $^{14}C-labelled$ 5-hydroxytryptophan showed an incorporation of radioactivity into brown pigment significantly higher than that of tryptophan. The brown pigment produced by Claviceps purpurea PRL 1980 seems to be derived from tryptophan through 5-hyrdroxytryptophan.

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Expression of TRP Channels in Mouse Dental Papilla Cell-23 (MDPC-23) Cell Line

  • Shin, Myoung-Sang;Yeon, Kyu-Young;Oh, Seog-Bae;Kim, Joong-Soo
    • International Journal of Oral Biology
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    • v.31 no.4
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    • pp.135-140
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    • 2006
  • Temperature signaling can be initiated by members of transient receptor potential (thermo-TRP) channels. Hot and cold substances applied to teeth usually elicit pain sensation. Since odontoblasts constitute a well-defined layer between the pulp and the mineralized dentin, being first to encounter thermal stimulation from oral cavity, they may be involved in sensory transduction process, in addition to their primary function as formation of dentin. We investigated whether thermo-TRP channels are expressed in a odontoblast cell line, MDPC-23. The expressions of thermo-TRP channels were examined using reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, fluorometric calcium imaging. Analysis of RT-PCR revealed mRNA expression of TRPV1, TRPV2, TRPV4 and TRPM8, but no TRPV3, TRPA1. Immunohistochemical approach failed to detect TRPV1 expression. Whereas the application of 4-phorbol-12,13-didecanoate($10\;{\mu}M$, a TRPV4 agonist), menthol(1 mM, a TRPM8 agonist) and icilin($10\;{\mu}M$, a TRPM8 agonist) produced the enhancement of intracellular calcium concentration, capsaicin($1\;{\mu}M$, a TRPV1 agonist) did not. Our results suggest that subfamily of thermo-TRP channels expressed in odontoblasts may serve as thermal or mechanical transducer in teeth.

A Chromo- and Fluoroionophoric Thiaoxaaza-Macrocycle Functionalized with Nitrobenzofurazan Exhibiting Mercury(II) Selectivity

  • Lee, Ji-Eun;Lee, Shim-Sung;Choi, Kyu-Seong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.12
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    • pp.3707-3710
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    • 2010
  • A chromo/fluorogenic $NO_2S_2$-macrocycle L functionalized with nitrobenzofurazan unit as a dual-signaling probe was synthesized and structurally characterized by single crystal X-ray analysis. In a cation-induced color change experiment, L exhibited excellent $Hg^{2+}$ ion selectivity by showing the color change from orange-red to yellow. However, this hypochromic shift by $Hg^{2+}$ was observed for the weaker coordinating anion system such as ${NO_3}^-$ and ${ClO_4}^-$ ions. The observed anion effect is due to the strong coordination of anions inhibits the bond formation between $Hg^{2+}$ and the macrocyclic tert-N atom, which is sensitive to induce the color change. In the fluorometric experiment, L showed chelate-enhanced fluorescence change effect only with $Hg^{2+}$ ion, together with a change from yellow to green emission. The sensing ability for $Hg^{2+}$ with the proposed chemosensor L is due to the stable complexation with 1:1 stoichiometry (metal-to-ligand).

A Carbazole-Attached NO2S2-Macrocycle Exhibiting Hg2+ and Cu2+ Selectivity

  • Lee, Seul-Gi;Kang, Eun-Ju;Lee, Shim Sung
    • Bulletin of the Korean Chemical Society
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    • v.34 no.5
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    • pp.1429-1434
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    • 2013
  • A synthesis and cation-induced fluorescent behavior of the carbazole-attached $NO_2S_2$-macrocycle (L) is described and structurally characterized by single crystal X-ray analysis. The photoluminescence spectrum of L in 80% $CH_3CN/CH_2Cl_2$ displays a peak maximum at 431 nm (blue emission). In the metal-induced fluorometric experiment, L showed a drastic chelation-enhanced fluorescence quenching (CHEQ) effect only with $Hg^{2+}$ and $Cu^{2+}$. In ESI-mass study, a 1:1 stoichiometry for complexation of L with $Hg^{2+}$ was confirmed, suggesting the unique sensing behavior of the proposed ligand L due to the selective complexation affinity for $Hg^{2+}$. The observed results indicate that L is a promising turn-off type fluoroionophore for $Hg^{2+}$ and $Cu^{2+}$ detections. Additionally, the $Ag^+$ complex of the precursor macrocycle was prepared and its solid structure was crystallographically characterized.