• 제목/요약/키워드: UV fluorescent

검색결과 143건 처리시간 0.029초

국산 Thalictrum 속 식물 지상부의 성분검색 (Screening Test on the Constituents from the Stems of the Genus Thalictrum in Korea)

  • 이인란
    • 생약학회지
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    • 제3권1호
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    • pp.23-25
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    • 1972
  • Preliminary investigations were carried out to isolate the constituents from the stems of genus Thalictrum. Methanol extracts of eight species from the genus were examined by thin layer chromatography. The author observed three different spots with Dragendorff's reagent in Thalictrum actaefolium, whereas none was detected in Thalictrum tuberiferum and Thalictrum simplex. Various fluorescent colors with different Rf values were detected in all species by UV ray, suggesting that each species may have different components.

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Synthesis of Fluorescent Thiophene-derivatized Pentytiptycenes and Their Aggregate Behaviors

  • 송진우
    • 통합자연과학논문집
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    • 제3권1호
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    • pp.28-32
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    • 2010
  • Thiophene-derivatized pentiptycenes were synthesized and characterized by NMR and UV-Vis spectroscopy. Aggregation behavior of thiophene-derivatized pentiptycenes was monitored by the measurement of fluorescence. Fluorescence intensities for the thiophene-derivatized pentiptycenes and thiophene-derivatized pentiptycenes aggregates were compared. There is no shift in the maximum of the emission wavelength. In the range of water fraction between 20% and 40%, the emission intensity of thiophene-derivatized pentiptycene aggregates remains almost identical. Fluorescence efficiency incresaed by about 5 times higher when the thiophene-derivatized pentiptycenes forms the aggregates in solution.

A STUDY OF THE PHOTOTOXICITY OF ORANGE FLOWER ABSOLUTE

  • Yang, Hai-Joo;Lee, Neung-An
    • 대한화장품학회지
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    • 제13권1호
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    • pp.1-6
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    • 1987
  • We have confirmed the phototoxicity of orange flower absolute, studied the phototoxic ingredient and developed a method to eliminate it. To confirm the phototoxicity, we tested French orange flower absolute, Moroccan absolute and Egyptian absolute with Hartley strain guinea Pig under UV irradiation ranging from 320400 nm supplied with fluorescent lamps. Using a combination of isolation techniques including HPLC and IR, we were able to confirm that the phototoxic agent was bergapten. The development of a non-phototoxic orange flower absolute using ion exchange chromatography is described.

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메나디온에 의한 혈소판 내 칼슘 변화측정시 형광 색소 사용의 문제점 (Infeasibility of Measuring $Ca^{2+}$ in Menadione-Exposed Platelets Using Fluorescent Dyes)

  • 정선화;이무열;이주영;정승민;정진호
    • 약학회지
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    • 제41권6호
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    • pp.749-755
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    • 1997
  • It has been reported that dose-dependent $Ca^{2+}$ increase by menadione in platelets could be measured by fluorescent dye, quin-2. The problems will be described here rel ating to measuring $Ca^{2+}$ in menadione-exposed platelets using fura-2 and fluo-3, widely used fluorescent indicators. Additions of menadione to fura-2 loaded platelets and their lysates resulted in marked reduction in fluorescence intensity at both 340nm ($Ca^{2+}$-unbound form) 380nm ($Ca^{2+}$-undbound form) excitation wavelengths. Fura-2 excitation spectra were overlapped with UV-visible absorption spectra of menadione, suggesting that light absorption by menadione itself could quench fluorescence generated by fura-2. Next approach was to use fluo-3 which has the higher wavelength (490nm) of excitation. Previous work demonstrated that treatment with probenecid to platelets was required to prevent fluo-3 dye leakage. However, probenecid itself was proven to be inadequate to measure the concentration of intracellular $Ca^{2+}$; by reducing menadione-induced cytotoxicity in platelets. Our results suggest that it is not feasible to measure $Ca^{2+}$ in platelets by using fura-2 and fluo-3 in the presence of probenecid, and cautions should be taken to measure changes of intracellular $Ca^{2+}$ levels by fluorescent dyes following chemical exposure.

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$오존/UV/H_2O_2$를 이용한 몰리브덴(Mo) 용해 반응에 따른 청정기술 개발에 관한 연구 (A clean technology development using the molybdenum dissolution reaction with hydrogen peroxide/UV/Ozone)

  • 김재우;홍종순;신대윤
    • 환경위생공학
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    • 제14권4호
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    • pp.143-149
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    • 1999
  • In the tungsten industry as light source material, tungsten filament which used as light source material could form after molybdenumwire which used as the center supporter for coil shape tungsten wire was removed. This process uses hydrogen peroxide, Ozone and UV(Ultraviolet)Lamp, for the quantity of hydrogen peroxide decrease. The results were as follows : 1. An incandescent electric Lamp type : FL(FL-20) type : A standard of commodity (P.W.: $19{\pm}1.0mg$, $C.R:4.5{\pm}0.3{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time : 65Min., P.W.: 18.60mg, $C.R.:4.60{\Omega}$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide; Reaction Time : 64Min., P.W.: 18.61mg, C.R.: $4.61{\Omega}$ 2. A Fluorescent Lamp Type : GLS(GLS-40) Type : A standard of commodity(P.W.: $11.8{\pm}0.2mg$$65{\pm}1.5{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time: 72Min, P.W.:11.88mg, C.R.: $65.62\Omega$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide;Reaction Time:71Min., P.W.:11.88mg, C.R.: $65.63\Omega$

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MODEL CALCULATIONS OF THE UV - EXCITED MOLECULAR HYDROGEN IN INTERSTELLAR CLOUDS

  • Lee, Dae-Hee;Pak, Soo-Jong;Seon, Kwang-Il
    • 천문학논총
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    • 제20권1호
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    • pp.7-10
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    • 2005
  • We have calculated 2448 interstellar cloud models to investigate the formation and destruction of high rotational level $H_2$ according to the combinations of five physical conditions: the input UV intensity, the $H_2$ column density, cloud temperature, total density, and the $H_2$ formation rate efficiency. The models include the populations of all the accessible states of $H_2$ with the rotational quantum number J < 16 as a function of depth through the model clouds, and assume that the abundance of $H_2$ is in a steady state governed primarily by the rate of formation on the grain surfaces and the rates of destruction by spontaneous fluorescent dissociation following absorption in the Lyman and Werner band systems. The high rotational levels J = 4 and J = 5 are both populated by direct formation into these levels of newly created molecules, and by pumping from J = 0 and J = 1, respectively The model results show that the high rotational level ratio N(4)/N(0) is proportional to the incident UV intensity, and is inversely proportional to the $H_2$ molecular fraction, as predicted in theory.

Aflatoxin 존재하에서의 수용액중 Malonadehyde 의 광화학적 변화 (Photochemical Changes of Malonaldehyde by the Presence of Aflatoxins in Model Systems)

  • 권태환
    • 한국식품과학회지
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    • 제1권1호
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    • pp.45-50
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    • 1969
  • 자외부흡광 스펙트럼의 변화와 티 비 에이(TBA) 반응으로 살필 때, 수용액의 송에서의 말론알데하이드(malonaldehyde)는 과장 $260m/{\mu}$ 부근의 자외선조명에 의하여 광화학적 변화를 받는다. 이 용액에 아프라톡신(aflatoxin) 을 가하면 파장 $360m/{\mu}$ 부근의 광선에 의해서 이와 같은 변화가 재빨리 일어나며, 또 보통 형광등을 이용한 실험실의 조명에 의해서도 비록 그 변화는 느려지지만 마찬가지로 일어난다. 이과 같은 변화는 비가역적이며, 이 반응에서 아프라톡신은 다만 감광제로서의 역할을 한다. 또 이 반응의 기작은 말론알데하이드 분자의 평행적 이중결합체 형성에 의한 것 같다.

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양파껍질에서 분리된 용매 추출물의 항산화효과 (Antioxidant Activity of Solvent Extract from Onion Skin)

  • 나경수;서형주;정수현;손종연
    • 한국식품과학회지
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    • 제29권3호
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    • pp.595-600
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    • 1997
  • 양파껍질중에 존재하는 항산화물질을 여러 용매로 분획하여 그 항산화효과를 비교하고, butanol fraction의 TLC에 의한 재분획 및 총페놀함량, 수소공여능 및 UV spectral 분석을 행하였다. 메타놀추출물의 항산화 효과는 첨가농도가 증가함에 따라 증가되었다. 메타놀추출물의 용매 분획물의 항산화효과는 buthanol> ethyl acetate> ethyl ether>water fraction의 순으로 나타났다. 이들의 항산화효과는 총페놀함량 및 수소공여능과 밀접한 관계를 보였다. TLC에 의한 butanol fraction의 재분획 결과 Rf치 0.20, 0.33, 0.49, 0.60 및 0.94을 나타내는 형광띠를 나타내었다. Rf치 0.94의 형광 band는 다른 형광 band에 비해 현저히 강한 것으로 보여 주었으며 flavonol의 존재를 나타내는 에서 나타나는 255 nm와 317 nm에서 강한 흡수가 보였다. Spectral analyses 결과 양파껍질 중에 함유되어 있는 주요 항산화성 물질은 quercetin aglycone (3,3',4',5,7-pentahydroxyflavone)인 것으로 확인되었다.

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Enhancement of Photoluminescence by Ag Localized Surface Plasmon Resonance for Ultraviolet Detection

  • Lyu, Yanlei;Ruan, Jun;Zhao, Mingwei;Hong, Ruijin;Lin, Hui;Zhang, Dawei;Tao, Chunxian
    • Current Optics and Photonics
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    • 제5권1호
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    • pp.1-7
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    • 2021
  • For higher sensitivity in ultraviolet (UV) and even vacuum ultraviolet (VUV) detection of silicon-based sensors, a sandwich-structured film sensor based on Ag Localized Surface Plasmon Resonance (LSPR) was designed and fabricated. This film sensor was composed of a Ag nanoparticles (NPs) layer, SiO2 buffer and fluorescence layer by physical vapour deposition and thermal annealing. By tuning the annealing temperature and adding the SiO2 layer, the resonance absorption wavelength of Ag NPs matched with the emission wavelength of the fluorescence layer. Due to the strong plasmon resonance coupling and electromagnetic field formed on the surface of Ag NPs, the radiative recombination rate of the luminescent materials and the number of fluorescent molecules in the excited state increased. Therefore, the fluorescent emission intensity of the sandwich-structured film sensor was 1.10-1.58 times at 120-200 nm and 2.17-2.93 times at 240-360 nm that of the single-layer film sensor. A feasible method is provided for improving the detection performance of UV and VUV detectors.

형광 단백질 mCherry-I202T의 pH 감응성 분석 (Characterization of pH Dependent Properties of mCherry Mutant, I202T)

  • 이상민;정민섭
    • 공업화학
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    • 제32권1호
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    • pp.10-14
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    • 2021
  • DsRed에서 유래한 적색 형광 단백질들 중 하나인 mCherry는 GFP와 유사한 3차 구조를 가진 잘 알려진 적색 형광 단백질 중 하나이며, 수소결합 네트워크를 형성하고 있지 않아서 pH 변화에 민감하지 않다. 반면 mCherry의 발색단 근처에서 돌연변이를 야기 시켜 만든 mCherry-I202T는 mCherry 단백질의 202번째 아미노산인 이소루신(Ile)을 트레오닌(Thr)으로 치환함으로써 모체와는 다르게 추가적인 수소결합을 형성하여, 주위 pH에 더욱 민감하게 반응할 뿐 아니라 적색 편이된 형광을 보였다. 수소결합이 확장된 I202T의 pH 민감성을 검증하기 위해 산성과 염기성 pH 범위에서 I202T의 UV-vis 흡광 스펙트럼 변화와 가역성을 확인하고, 그를 pH sensor에 적용 가능한지 그 가능성을 검증하고자 하였다.