• 대한한의진단학회지
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• 제15권1호
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• pp.47-54
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• 2011

In traditional Korean medicine, inspection of the tongue is an important method of making medical diagnoses and determining prognosis. We surveyed the fluorescence characteristics of the tongue coat in the ultraviolet light. The tongue coat comprises micro-organisms, blood metabolites, leukocytes from periodontal pockets, large amounts of desquamated epithelial cells released from the oral mucosa and different nutrients. In the ultraviolet light tissues of the oral cavity generally emit weak red or green fluorescence, which is not easily seen by the human eye, but is readily detected. This fluorescence has been proved to be due to the production of porphyrins by oral micro-organisms. While the composition of motile micro-organisms on the dorsum of the tongue is not constant, variations also occur persistingly in the fluorescence characteristics of the tongue coat. But because live bacteria contain a variety of intracellular biomolecules that have specific excitation and emission wavelength spectra characterizing their intrinsic fluorescence, the tongue coat emits fluorescence. the tongue itself, on the other hand, emits very weak or not fluorescence. In conclusion, we suggests that the uncoated tongue area be eliminated from the coated tongue area with the difference between the fluorescence characteristics of the tongue and that of the tongue coat.

• 한국수산과학회지
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• 제25권3호
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• pp.219-228
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• 1992

와편모조류, 남조류, Chloromonadophyceae와 Cryptophyceae를 포함한 12종의 해양 식물플랑크톤의 일차적 형광특성을 in vivo 상태에서 조사하였다. 형광과 exciatation 스펙트럼을 측정한 결과 약 380-435nm 영역에서 강한 세기의 형광 스펙트럼이, 조사된 모든 식물플랑크톤으로부터 얻어졌다. 식물플랑크톤의 성장 상태의 변화에 따른 형광 스펙트럼의$\lambd_{max}$에 대한 영향을 관찰하였다. 관찰된 형광 스펙트럼의 형광소를 밝히기 위하여, 식물플랑크톤의 구성성분 중에 유사한 형광 특성을 보이는 8가지 pteridine계 화합물의 phosphate 완충용액에 대한 형광 특성과 식물플랑크톤의 380-435nm 영역에서 나타난 스펙트럼의 세기와 모양, $\lambd_{max}$를 비교하였다. 식물플랑크톤의 fluorescence lifetime$(\tau)$과 fluorescence decay curve를 식물플랑크톤에 존재하는 유기화합물들의 표준용액의 $\tau$값과 비교하였다. 430 nm의 들뜨기 파장을 사용하여 얻은 식물플랑크톤의 fluorescence decay는 biexponential과 triexponential decay를 보였다. 박테리아와 식물플랑크톤의 형광 특성을 비교한 결과 형광 스펙트라뿐 아니라 붕괴 양상도 현저한 차이점을 보였다.

• 한국물환경학회지
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• 제23권6호
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• pp.843-849
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• 2007

Monitoring of NOM characteristics is important for improving removal efficiency of natural organic matter (NOM) in water treatment processes. In this study, several NOM characteristics, which include specific UV absorbance (SUVA), total carbonate content, molecular weight distribution, and fluorescence properties, were measured using samples collected from a pilot-scale water treatment plant consisting of coagulation/flocculation (C/F), filtration, ozonation and granular activated carbon (GAC) processes. The highest removal of NOM was observed in C/F and filtration processes as demonstrated by the reduction of dissolved organic carbon (DOC) by 25% and 21%, respectively. Despite nearly no change in DOC, however, the lowest SUVA value and the highest total carbohydrate content were observed in the sample from ozonation process. This indicates that non-degradable aromatic compounds become depleted and biodegradable organic compounds are enriched during the process. Comparison of synchronous fluorescence spectra of the samples showed that ozoation process increased protein-like fluorescence while it decreased fulvic-like and terrestrial humic-like fluorescence. Consistently, a slight peak of protein-like fluorescence was observed in the sample from ozonation process. The greatest change in molecular weight distributions of the samples was observed in C/F process. Comparison of size exclusion chromatogram of the samples revealed that NOM fractions with the molecular weight greater than 2000 Da were reduced by over 90% after C/F process. SUVA values and total carbohydrate content of the samples were well correlated with a ratio of protein-like fluorescence and terrestrial humic-like fluorescence intensities with the correlation coefficients of 0.99 and 0.91, respectively. This suggests that synchronous fluorescence properties of NOM could be used as useful tolls for monitoring changes of some NOM characteristics during water treatment processes.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권5호
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• pp.18-25
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• 2014

Traditional investigation procedures of soil and groundwater contamination are followed by soil gas sampling, soil sampling, groundwater sampling, establishment of monitoring wells, and groundwater monitoring. It often takes several weeks to obtain the analysis reports, and sometimes, it needs supplemental sampling and analysis to delineate the polluted area. Laser induced fluorescence (LIF) system is designed for the detection of free-phase petroleum pollutants, and it is suitable for on-site real-time site investigation when coupling with a direct push testing tool. Petroleum products always contain polycyclic aromatic hydrocarbon (PAH) compounds possessing fluorescence characteristics that make them detectable through LIF detection. In this study, LIF spectroscopy of 5 major fuel products was conducted to establish the databank of LIF fluorescence characteristic spectra, including gasoline, diesel, jet fuel, marine fuel and low-sulfur fuel. Multivariate statistical tools were also applied to distinguish LIF fluorescence characteristic spectra among the mixtures of selected fuel products. This study successfully demonstrated the feasibility of identifying fuel species based on LIF characteristic fluorescence spectra, also LIF seemed to be uncovered its powerful ability of tracing underground petroleum leakages.

• Current Optics and Photonics
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• 제5권5호
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• pp.554-561
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• 2021

Indocyanine green (ICG) is a cyanine dye that has been used in medical diagnostics based on fluorescence imaging, and in medical therapy based on the photothermal effect. It is important to systematically understand the photothermal effect and fluorescence characteristics of ICG simultaneously. By varying a number of conditions such as laser power density, laser irradiation wavelength, concentration of ICG solution, and exposure time of laser irradiation, the intensity properties of fluorescence and the temperature change induced by the photothermal effect are measured simultaneously using a charge-coupled-device camera and a thermal-imaging camera. The optimal conditions for maximizing the photothermal effect are determined, while maintaining a relatively long lifetime and high efficiency of the fluorescence for fluorescence imaging. When the concentration of ICG is approximately 50 ㎍/ml and the laser power density exceeds 1.5 W/cm², the fluorescence lifetime is the longest and the temperature induced by the photothermal effect rapidly increases, exceeding the critical temperature sufficient to damage human cells and tissues. The findings provide useful insight into the realization of effective photothermal therapy, while also specifying the site to be treated and enabling real-time treatment monitoring.

• 생태와환경
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• 제44권3호
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• pp.292-302
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• 2011

본 연구는 공단, 도심 및 농촌유역의 서로 다른 유역특성을 갖고 있는 시화호 유역을 대상으로 형광분석을 통해 각 소유역 유입하천에서의 오염물질 유출특성을 분석하였다. 4TG는 강우시 시공간적 오염물질 유출특성 분석 결과, 초기세척효과가 강하게 나타나 강우초기 단백질 및 휴믹계열의 고농도의 오염물질이 빠르게 유출된 후, 다시 유량증가에 따른 희석효과로 인해 오염물질 유출농도가 급격하게 감소하는 유출특성을 나타내고 있다. AS는 다른 도심유역 하천들이 갖고 있는 강우시 오염물질 유출 특성과는 다른 양상을 나타내고 있다. 토지이용특성상 도심유역 특성을 나타내고 있지만, 신도시 조성시 하천주변에 공원과 수변완충지역이 조성되어 있어 강우시 오염물질 유출속도를 저감시키는 역할을 하고, 단백질계열의 오염물질과 함께 휴믹계열의 오염물질도 함께 유출되는 유출특성을 나타내고 있다. MS는 입자성 오염물질과 함께 단백질계열의 오염물질 유입 현상이 뚜렷하게 나타나고 있어 단백질계열의 오염물질 저감방안이 함께 수립되어야 한다. 농촌유역 하천은 초기세척효과가 나타나지 않고, 후기유출현상이 강하기 때문에 충분한 사전 조사를 통해 오염물질이 최고농도에 도달하는 시점을 대상으로 선택적인 유역관리가 필요하다.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1315-1327
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• 2002

The model compounds, 8-methoxypsoralen-CH2O(CH2)n-adenine (MOPCH2OCnAd, n=2, 3, 5, 6, 8, and 10) in which 5 position of 8-methoxypsoralen (8-MOP) is linked by various lengths of polymethylene bridge to N9 of adenine. UV absorption spectra are identical with the sum of MOPCH2OC3 and adenine absorption spectra. Solvent effects on the UV absorption and fluorescence emission spectra indicate that the lowest excited singlet state is the $(\pi${\rightarrow}$\pi*)$ state. The spectral characteristics of the fluorescence of MOPCH2OCnAd are strongly dependent upon the nature of the solvents. The fluorescence emission spectra in aprotic solvents are broad and structureless due to the excimer formation through the folded conformation accelerated by hydrophobic ${\pi}-{\pi}$ stacking interaction. Increasing polarity of the protic solvents leads to higher population of unfolded conformation stabilized through favorable solvation and H-bonding, and consequently to an increase in the fluorescence intensity, fluorescence lifetime, and a shift of fluorescence maximum to longer wavelengths. The decay characteristics of the fluorescence in polar protic solvents shows two exponential decays with the lifetimes of 0.6-0.8 and 1.6-1.9 ns in 5% ethanol/water, while MOPCH2OC3 shows 0.5 and 1.7 ns fluorescence lifetimes. The long-lived component of fluorescence can be attributed to the relaxed species (i.e., the species for which the solvent reorientation (or relaxation) has occurred), while the short-lived components can be associated with the unrelaxed, or only partially relaxed, species.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.958-960
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• 1992

The fluorescence characteristics of near UV dye, BBQ pumped by Ar flashlamp have been studied for various electrical input energies applied to the flashlamp and argon fill pressures in the flash tube. The peak wavelength of fluorescence is about 380nm when the fluorescence intensity is at the peak value. The rise time of the fluorescence pulse is about 7 $\mu$sec and its FWHM is about 55$\mu$sec.

• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.268-272
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• 2005

Different detection characteristics of fluorescence immunochromatography method and high performance liquid chromatography (HPLC) method for the analysis of cyanobacterial toxins were studied. In particular, low and high limits of detection, detection time and reproducibility and detectable microcystin species were compared when fluorescence immunochromatography method and high performance liquid chromatography method were applied for the detection of microcystin (MC), a cyclic peptide toxin of the freshwater cyanobacterium Microcystis aeruginosa. A Fluorescence immunochromatography assay system has the unique advantages of short detection time and low detection limit, and high performance liquid chromatography detection method has the strong advantage of individual quantifications of several species of microcystins.

• Ocean Science Journal
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• 제42권1호
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• pp.49-59
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• 2007

Besides empirical algorithms with the blue-green ratio, the algorithms based on fluorescence are also important and valid methods for retrieving chlorophyll-a concentration in the ocean waters, especially for Case II waters and the sea with algal blooming. This study reviews the history of initial cognitions, investigations and detailed approaches towards chlorophyll fluorescence, and then introduces the biological mechanism of fluorescence remote sensing and main spectral characteristics such as the positive correlation between fluorescence and chlorophyll concentration, the red shift phenomena. Meanwhile, there exist many influence factors that increase complexity of fluorescence remote sensing, such as fluorescence quantum yield, physiological status of various algae, substances with related optical property in the ocean, atmospheric absorption etc. Based on these cognitions, scientists have found two ways to calculate the amount of fluorescence detected by ocean color sensors: fluorescence line height and reflectance ratio. These two ways are currently the foundation for retrieval of chlorophyll-a concentration in the ocean. As the in-situ measurements and synchronous satellite data are continuously being accumulated, the fluorescence remote sensing of chlorophyll-a concentration in Case II waters should be recognized more thoroughly and new algorithms could be expected.