• 한국의학물리학회지:의학물리
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• 제12권1호
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• pp.79-94
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• 2001

생물학적 조직(Biological Tissue)에서 얻어내는 형광(Fluorescence)은 산란(Scattrering), 흡수(Absorption), 그리고 형광체(Fluorophores)가 원인이 되는, 인트린식 형광(Intrinsic Fluorescence)들에 관한 정보를 갖고 있다. 생물학적 조직의 형광스펙트럼은 조직 내에 존재하는 흡수체(Absorber)와 산란물질(Scatters)들의 영향을 받기 때문에 다른 조직의 생화학적인 인트린식 형광을 선형적인 조합으로 해석할 수 없었다. 생물학적 조직 같은 터비드 매질(Turbid Media)로부터 실험적으로 형광을 얻어서 산란과 흡수의 영향을 조사하기 위하여 본 연구소에서 제작한 장치를 소개하고, 넓은 범위의 흡수체와 산란물질의 농도를 갖고 제작한 조직 팬텀(Tissue Phantom)에 대한 형광과 반사(Reflectance) 스펙트럼을 측정하였다. 형광스펙트럼에 존재하는 산란과 흡수의 왜곡(Distortion)을 제거하기 위하여, 반사스펙트럼에 포함된 산란과 흡수 정보를 이용하는 ‘광자 이동 모델(Photon Migration Model)’을 적용하였고, 이러한 조직모델에 대한 인트린식 형광을 얻었다 연구 결과, 모델 값과 실제 인트린식 형광 스펙트럼이 훌륭하게 일치함을 확인하였다. 이런 연구를 하게된 동기는, 인간의 조직이 병들어서 진화하면 조직의 생화학적 구성의 변화가 발생하고 이때 인트린식 형광의 변화가 생기기 때문이다 결론적으로, 조직에 대한 실시간 광학적 생검에서 병든 조직과 정상조직을 단지 형광스펙트럼만으로 구분하는 것은 어렵지만, 인트린식 형광을 이용하면 가능하다.

• Fibers and Polymers
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• 제6권2호
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• pp.127-130
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• 2005

Intrinsic UV reflection and fluorescence behaviors of polycarbonate, polyurethane and poly(ethylene terephthalate) films were investigated in order to characterize the interaction of water in these films. During water sorption process, UV reflection spectra of polycarbonate and polyurethane films showed little peak position changes. Fluorescence emission spectra of polycarbonate films showed red spectral shifts from 332 nm with water immersion time. This red-shifted peak could be due to phenyl-2-phenoxybenzoate, which is one of the major thermal degradation products in polycarbonate. Fluorescence peaks of polyurethane films appeared at two different positions and the ratio of these peak intensities increased with increasing immersion time. In the case of PET films, the UV reflection spectrum showed the peak intensity around 340 nm to change in response to water sorption. The fluorescence near 388 nm probably due to ground state dimer exhibited sensitivity with water sorption, when excited at 340 nm.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.2011-2014
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• 2010

The fluorescence intensity of a single-stranded oligonucleotide containing a fluorene-labeled deoxyuridine $(U^{Fl})$ unit increases by only 1.5-fold upon formation of its perfectly matched duplex. To increase the fluorescence signal during hybridization, we positioned a quencher strand containing a deoxyguanine (dG) nucleobase, functioning as an internal quencher, opposite to the $U^{Fl}$ unit to reduce the intrinsic fluorescence upon hybridization with a probe. From an investigation of the optimal length of the quencher strand and the effect of the neighboring base sequence, we found that a short strand (five-nucleotide) containing all natural nucleotides and dG as an internal quencher was effective at reducing the intrinsic fluorescence of a linear beacon; it also exhibited high total discrimination factors for the formation of perfectly matched and single base-mismatched duplexes. Such assays that function based on clear changes in fluorescence in response to single-base nucleotide mutations would be useful tools for accelerating diagnoses related to various diseases.

• BMB Reports
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• 제30권4호
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• pp.240-245
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• 1997

Interactions between ganglioside $G_{M3}$ and glucose transporter, GLUT1 were studied by measuring the effect of $G_{M3}$ on steady-state and time-resolved fluorescence of purified GLUT1 in synthetic lipids and on the 3-O-methylglucose uptake by human erythrocytes. The intrinsic tryptophan fluorescence showed a GLUT 1 emission maximum of 335 nm, and increased in the presence of $G_{M3}$ by 12% without shifting the emission maximum, The fluorescence lifetimes of intrinsic tryptophan on GLUT1 consisted of a long component of 7.8 ns and a short component of 2,3 ns and $G_{M3}$ increased both lifetime components. Lifetime components were quenched by acrylamide and KI. Acrylarnide-mduced quenching of long-lifetime components was partly recovered by $G_{M3}$ However. KI-induccd quenching of short- and long-lifetime components was not rescued by $G_{M3}$. The anisotropy of 1.6-diphenyl-1.3.5-hexatriene (DPH)-probed dimyristoylphosphatidylcholine (DMPC) model membrane was also increased with $G_{M3}$ incorporation, The transport rate of 3-O-methylglucose increased by 20% with $G_{M3}$ incorporation on the erythrocytes, Therefore, $G_{M3}$ altered the environment of lipid membrane and induced the conformational change of GLUT1.

• 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.

• Bulletin of the Korean Chemical Society
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• 제9권4호
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• pp.202-206
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• 1988

In order to investigate the oligomerization state of the plasma membrane proteolipid apoprotein purified from the bovine kidney, fluorescence polarization experiment was carried out in the two different solvent systems, i.e., water and organic solvent(chloroform-methanol). The molecular volumes of the proteins estimated from the Perrin equation, were to be 45,258$A^3$ and 17,608$A^3$ in water and organic solvent, respectively. These values indicate that a trimerization is possibly occurring in the aqueous environment. As an auxiliary experiment for the calculation of the molecular volume using Perrin equation, fluorescence quenching constants ($K_q$) with the quencher acrylamide and fluorescence lifetimes (${\tau}_F$) of the intrinsic fluorophore tryptophan residue were estimated in the two different solvent systems. $K_q$ in water was 18.21$M^{-1}$ and it was 46.24$M^{-1}$ in organic solvent. Fluorescence lifetimes of tryptophan residue were calculated to be 2.80 nsec. in water and 3.81 nsec. in organic solvent, respectively.

• 대한환경공학회지
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• 제29권5호
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• pp.540-547
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• 2007

본 연구에서는 한강원수로부터 물리화학적인 분리방법으로 휴믹물질(HS; humic substances)을 분리하여 HS의 계절별 분포특성을 조사하고, 식물분해산물에 의한 유기물 구성이 지배적인 자연형 하천수로부터 추출된 HS와 함께 다양한 분광학적 특성분석을 통하여 구조화학적 특성을 비교하고 그 기원특성을 평가하였다. 한강원수로부터 분리된 HS(HRHS)의 구성분율은 연평균 47.0%로, 건기에 비해서 우기에 상대적으로 높은 것으로 나타났다. HRHS는 다른 지역의 수계에서 추출된 HS보다 방향성(aromaticity)과 부식화도 (humification degree)가 상대적으로 낮은 것으로 조사되었으며, 이는 수환경계에서 부식화가 진행되는 유기물질의 기원특성과 이들 물질이 축합반응(polymerization)에 기여하는 정도에 따라서 그 구조화학적 성질이 차이를 나타내기 때문으로 보인다. 적외선분광(FT-IR)과 양성자핵자기공명$(^1H-NMR)$ 그리고 형광(fluorescence)분석은 HRHS와 상용화된 HS 간의 구조화학적 차이를 명확히 나타내었으며, FT-IR 및 $^1H-NMR$과 같은 전통적인 분광분석법에 비해서 상대적으로 단순화된 전처리과정과 짧은 응답시간을 요하는 형광분석법이 분석절차상 HS의 방향성 및 부식화도를 평가하기 위한 가장 효율적인 분석수단으로 평가되었다.

• BMB Reports
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• 제32권6호
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• pp.521-528
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• 1999

The folding of recombinant hepatitis B virus X-protein (rHBx) solubilized from Escherichia coli inclusion bodies was investigated. By sequential dialysis of urea, rHBx was folded into its native structure, which was demonstrated by the efficacy of its transcriptional activation of the adenovirus major late promoter (MLP), fluorescence spectroscopy, and circular dichroism (CD) analysis. The decrease in CD values at 220 nm and a corresponding blue shift of the intrinsic fluorescence emission confirmed the ability of rHBx to refold in lower concentrations of urea, yielding the active protein. Equilibrium and kinetic studies of the refolding of rHBx were carried out by tryptophan fluorescence measurements. From the biphasic nature of the fluorescence curves, the existence of stable intermediate states in the renaturation process was inferred. Reverse phase-high performance liquid chromatography (RP-HPLC) analysis further demonstrated the existence of these intermediates and their apparent compactness.

• BMB Reports
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• 제43권11호
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• pp.766-771
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• 2010

The biological evaluation of a new synthesized Pt(II)-complex, 2,2'-bipyridin Butylglycinato Pt(II) nitrate, an anti-tumor component, was studied at different temperatures by fluorescence and far UV circular dichroism (CD) spectroscopic methods. Human serum albumin (HSA) and human tumor cell line K562 were as targets. The Pt(II)-complex has a strong ability to quench the intrinsic fluorescence of HSA. Binding and thermodynamic parameters of the interaction were calculated by fluorescence quenching method. Far-UV-CD results showed that Pt(II)-complex induced increasing in content of $\alpha$ helical structure of the protein and stabilized it. The 50% cytotoxic concentration ($Cc_{50}$) of complex was determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay at different incubation times. Also, fluorescence staining with DAPI (4,6-diamidino-2-phenylindole) revealed some typical nuclear changes, which are characteristic of apoptosis. Above results suggest that Pt (II) complex is a promising anti-proliferative agent and should execute its biological effects by inducing apoptosis.

• 미생물학회지
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• 제50권4호
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• pp.275-280
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• 2014

루신-반응 조절 단백질(Lrp)은 18.8 kDa의 분자량을 갖는 164개의 아미노산으로 이루어진 글로벌 조절 단백질으로서, 야생형의 단백질(Lrp Wt)에는 아미노산 중 가장 강한 자체 형광을 띠는 트립토판이 존재하지 않는다. Lrp 단백질의 구조변이에 대한 정보를 줄 수 있는 형광분석을 위하여 Lrp Wt과 트립토판이루신-반응 영역에 단지 하나 존재하는 돌연변이 단백질(Lrp R145W)을 분리 정제하였다. Lrp R145W 단백질은 이들 ilvIH 오페론에서 고안된 Lrp 결합 특정 DNA와 아미노산 루신과의 결합 후에 형광이 감소하였으며 acrylamide, urea 등에 의해서도 급격히 쇄광하는 양상을 보였다. 이들 형광 실험 결과는 Lrp의 3차원적 구조 및 배향을 연구에 중요한 정보를 제공하여 줄 수 있을 것이다.