• 제목/요약/키워드: Near-infrared fluorescence

검색결과 58건 처리시간 0.026초

일반화된 이차원 상관 분광학: 원리 및 응용 (Generalized Two-dimensional (2D) Correlation Spectroscopy: Principle and Its Applications)

  • 정영미;김승빈
    • 대한화학회지
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    • 제47권5호
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    • pp.447-459
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    • 2003
  • 일반화된 이차원 상관 분광학은 모든 분자 분광학 즉, 적외선 (infrared, IR), 근적외선 (near-infrared, NIR), 라만 (Raman) 및 형광 (fluorescence) 분광학뿐만 아니라 X-ray 회절, X-ray 흡수 분광학 (XAS), 크로마토그래피 (chromatography) 등에 적용되어 시간뿐만 아니라 온도, 압력, 농도, 조성과 같은 다른 물리적 변화인 외부 섭동 (perturbation) 아래에서 얻은 스펙트럼 분석의 새로운 분광학으로 다양한 분야의 연구가 활발히 진행 중이다. 또한 같은 외부 섭동 아래에서 얻은 완전히 다른 두 스펙트럼의 2D hetero-spectral correlation analysis가 가능하므로 다양한 분야 즉, 생체 물질, 고분자, 나노입자 등의 연구가 활발히 진행 중이다. 이런 다양한 분야의 응용성 때문에 ?일반??이차원 상관 분광학??물리, 분석, 고분자, 나노물질 및 생화학 연구에 새로운 방향을 제시할 수 있을 뿐만 아니라 바이오 나노기술 연구에 상승 효과를 제공할 수 있다. 본 논문은 "일반화된 이차원 상관 분광학"의 원리와 그 다양한 응용성을 본 저자들의 연구를 중심으로 소개하고자 한다.

Color Enhancement of Natural Sapphires by High Pressure High Temperature Process

  • Song, Jeongho;Noh, Yunyoung;Song, Ohsung
    • 한국세라믹학회지
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    • 제52권2호
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    • pp.165-170
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    • 2015
  • We employed the high-pressure high temperature (HPHT) process to enhance the colors of natural sapphires to obtain a vivid blue. First, we analyze the content of the coloring agent $Fe_2O_3$ using the wavelength dispersive X-ray fluorescence (WD-XRF) method. The HPHT procedure operates under 1 GPa at various temperatures of 1700, 1750, and $1800^{\circ}C$ for 5 minutes using a cubic press. We determine the color changes using the optical microscopic images, UV-VIS near-infrared (NIR) spectra, micro-Raman spectra, and Fourier transform-infrared (FT-IR) spectra for all sapphire samples before and after the treatment. The optical microscopic results indicate that the HPHT process can enhance the sapphire color to a vivid blue at temperatures above $1750^{\circ}C$. The UV-VIS-NIR spectra identify the color changes explicitly and quantitatively through providing the Lab color scales and color differences. Both results demonstrate that the colors of natural sapphires can be enhanced to a vivid blue using the HPHT process above $1750^{\circ}C$ under 1 GPa for 5 minutes.

무채혈 혈당 측정기의 혈당 측정 원리: 혈당 검출방법 중심으로 (Blood Glucose Measurement Principles of Non-invasive Blood Glucose Meter: Focused on the Detection Methods of Blood Glucose)

  • 안원식;김진태
    • 대한의용생체공학회:의공학회지
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    • 제33권3호
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    • pp.114-127
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    • 2012
  • Recent technical advancement allows noninvasive measurement of blood glucose. In this literature, we reviewed various noninvasive techniques for measuring glucose concentration. Optical or electrical methods have been investigated. Optical techniques include near-infrared spectroscopy, Raman spectroscopy, optical coherence technique, polarization, fluorescence, occlusion spectroscopy, and photoacoustic spectroscopy. Electrical methods include reverse iontophoresis, impedance spectroscopy, and electromagnetic sensing. Ultrasound, detection from breath, or fluid harvesting technique can be used to measure blood glucose level. Combination of various methods is also promising. Although there are many interesting and promising technologies and devices, there need further researches until a commercially available non-invasive glucometer is popular.

Photosensitized oxidative damage of human serum albumin by water-soluble dichlorophosphorus(V) tetraphenylporphyrin

  • Ouyang, Dongyan;Hirakawa, Kazutaka
    • Rapid Communication in Photoscience
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    • 제4권2호
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    • pp.41-44
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    • 2015
  • Biomolecular photo-damaging activity of a water-soluble cationic porphyrin was examined using human serum albumin (HSA), a water-soluble protein as a target biomolecule model by a fluorometry. Dichlorophosphorus(V) tetraphenylporphyrin ($Cl_2P(V)TPP$), was synthesized and used as a photosensitizer. This porphyrin could bind to HSA and cause the photosensitized oxidation of HSA through the singlet oxygen generation and the oxidative photo-induced electron transfer (ET). Near infrared emission spectroscopy demonstrated the photosensitized singlet oxygen generation by this porphyrin. Decrement of the fluorescence lifetime of $Cl_2P(V)TPP$ by HSA supported the ET mechanism. Furthermore, the estimated Gibb's energy indicated that the ET mechanism is possible in the terms of energy. Because oxygen concentration in cancer cell is relatively low, ET mechanism is considered to be advantageous for photosensitizer of photodynamic therapy.

분자영상의 적용분야 및 전망 (Application and Prospects of Molecular Imaging)

  • 최규락;이상복
    • 한국방사선학회논문지
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    • 제8권3호
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    • pp.123-136
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    • 2014
  • 본 논문에서는 분자영상을 분류하고 적용 분야와 미래를 예측해 보고자 하였다. 분자영상은 생체 내에서 분자수준과 세포수준에서 일어나는 변화를 영상화하는 것으로써 분자세포생물학과 첨단영상기술이 발전하여 접목된 새로운 분야이다. 분자영상은 형광, 생물발광, SPECT, PET, MRI, Ultrasound 등의 영상 기법들을 이용하여 유전자 치료 모니터링, 세포추적, 세포 치료 모니터링, 항체영상, 약제 개발, 분자 상호작용 영상, 근적외선 형광 물질을 이용한 암 형광 영상, Bacteria 를 이용한 종양 표적 영상, 치료효과 조기 평가, 치료 효과 예측 등에 적용되고 있다. 분자 영상의 미래는 분자세포 생물학, 유전학, 화학, 약학, 물리학, 전산학, 의공학, 핵의학, 영상의학, 임상의학 등 여러 학문 분야가 융합되어 상호협조와 공동연구를 통하여 발전해 나갈 것이다. 분자영상의 태동으로 미래의 의료의 모습은 질병의 조기진단과 개인 맞춤형 치료가 가능하게 될 것이다.

Relaxation Process of the Photoexcited State and Singlet Oxygen Generating Activity of Water-soluble meso-Phenanthrylporphyrin in a DNA Microenvironment

  • Hirakawa, Kazutaka;Ito, Yusuke;Yamada, Takashi;Okazaki, Shigetoshi
    • Rapid Communication in Photoscience
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    • 제3권4호
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    • pp.81-84
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    • 2014
  • To examine the microenvironmental effect of DNA on the photosensitized reaction, the electron-donor-connecting porphyrin, meso-(9-phenanthryl)-tris(N-methyl-p-pyridinio) porphyrin (Phen-TMPyP), was synthesized. Phen-TMPyP can bind to oligonucleotides with two binding modes, depending on the DNA concentration. The fluorescence lifetime measurement of Phen-TMPyP shows a shorter component than that of the reference porphyrin without the phenanthryl moiety. However, the observed value is much longer than those of previously reported similar types of electron-donor-connecting porphyrins, suggesting that electron-transfer quenching by the phenanthryl moiety is not sufficient. The fluorescence quantum yield of Phen-TMPyP ($5{\mu}M$) decreased with an increase in DNA concentration of up to $5{\mu}M$ base pair (bp), possibly due to self-quenching through an aggregation along the DNA strand, increased with an increase in DNA concentration of more than $5{\mu}M$ bp and reached a plateau. The fluorescence quantum yield of Phen-TMPyP with a sufficient concentration of DNA was larger than that of the reference porphyrin. The singlet oxygen ($^1O_2$) generating activity of Phen-TMPyP was confirmed by the near-infrared emission spectrum measurement. The quantum yield of $^1O_2$ generation was decreased by a relatively small concentration of DNA, possibly due to the aggregation of Phen-TMPyP, and recovered with a sufficient concentration of DNA. The recovered quantum yield was rather smaller than that without DNA, indicating the quenching of $^1O_2$ by DNA. These results show that a DNA strand can stabilize the photoexcited state of a photosensitizer and, in a certain case, suppresses the $^1O_2$ generation.

바이오 물질 분석을 위한 금속 나노입자를 이용한 SERS 분석 연구동향 (A Review of SERS for Biomaterials Analysis Using Metal Nanoparticles)

  • 장의순
    • 세라미스트
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    • 제22권3호
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    • pp.281-300
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    • 2019
  • Surface enhanced Raman scattering (SERS) was first discovered in 1974 by an unexpected Raman signal increase from Pyridine adsorbed on rough Ag electrode surfaces by the M. Fleishmann group. M. Moskovits group suggested that this phenomenon could be caused by surface plasmon resonance (SPR), which is a collective oscillation of free electrons at the surface of metal nanostructures by an external light source. After about 40 years, the SERS study has attracted great attention as a biomolecule analysis technology, and more than 2500 new papers and 500 review papers related to SERS topic have been published each year in recently. The advantages of biomaterials analysis using SERS are as follows; ① Molecular level analysis is possible based on unique fingerprint information of biomolecule, ② There is no photo-bleaching effect of the Raman reporters, allowing long-term monitoring of biomaterials compared to fluorescence microscopy, ③ SERS peak bandwidth is approximately 10 to 100 times narrower than fluorescence emission from organic phosphor or quantum dot, resulting in higher analysis accuracy, ④ Single excitation wavelength allows analysis of various biomaterials, ⑤ By utilizing near-infrared (NIR) SERS-activated nanostructures and NIR excitation lasers, auto-fluorescence noise in the visible wavelength range can be avoided from in vivo experiment and light damage in living cells can be minimized compared to visible lasers, ⑥ The weak Raman signal of the water molecule makes it easy to analyze biomaterials in aqueous solutions. For this reason, SERS is attracting attention as a next-generation non-invasive medical diagnostic device as well as substance analysis. In this review, the principles of SERS and various biomaterial analysis principles using SERS analysis will be introduced through recent research papers.

Lymphatic vessel mapping in the upper extremities of a healthy Korean population

  • Lee, Yun-Whan;Lee, Soo-Hyun;You, Hi-Jin;Jung, Jae-A;Yoon, Eul-Sik;Kim, Deok-Woo
    • Archives of Plastic Surgery
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    • 제45권2호
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    • pp.152-157
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    • 2018
  • Background Intraoperative indocyanine green (ICG) lymphography can effectively detect functioning lymph vessels in edematous limbs. However, it is sometimes difficult to clearly identify their course in later-stage edematous limbs. For this reason, many surgeons rely on experience when they decide where to make the skin incision to locate the lymphatic vessels. The purpose of this study was to elucidate lymphatic vessel flow patterns in healthy upper extremities in a Korean population and to use these findings as a reference for lymphedema treatment. Methods ICG fluorescence lymphography was performed by injecting 1 mL of ICG into the second web space of the hand. After 4 hours, fluorescence images of lymphatic vessels were obtained with a near-infrared camera, and the lymphatic vessels were marked. Three landmarks were designated: the radial styloid process, the mid-portion of the cubital fossa, and the lower border of the deltopectoral groove. A straight line connecting the points was drawn, and the distance between the connected lines and the marked lymphatic vessels was measured at 8 points. Results There were 30 healthy upper extremities (15 right and 15 left). The average course of the main lymph vessels passed $26.0{\pm}11.6mm$ dorsal to the styloid process, $5.7{\pm}40.7mm$ medial to the mid-cubital fossa, and $31.3{\pm}26.1mm$ medial to the three-quarters point of the upper landmark line. Conclusions The main functioning lymphatic vessel follows the course of the cephalic vein at the forearm level, crosses the mid-cubital point, and travels medially toward the mid-axilla.

The Characterization of Anti-HER-2/neu Monoclonal Antibody using Different in vivo Imaging Techniques

  • Moon, Cheol;Kim, Eun Jung;Choi, Dan Bee;Kim, Byoung Soo;Kim, Sa Hyun;Choi, Tae Hyun
    • 대한의생명과학회지
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    • 제21권1호
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    • pp.23-31
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    • 2015
  • Recently, specific antibodies have been used extensively to diagnose and treat various diseases. It is essential to assess the efficacy and specificity of antibodies, especially the in vivo environment. Anti-HER-2/neu mAb was evaluated as a possible transporting agent for radioimmunotherapy. The monoclonal antibody was successfully radio-labeled with $^{131}I$. In vitro binding assays were performed to confirm its targeting ability using another radio-iodine, $^{125}I$. Binding percentage of $^{125}I$ labeled anti-HER-2/neu mAb in HER-2/neu expressing CT-26 cells was found to be 4.5%, whereas the binding percentage of $^{125}I$ labeled anti-HER-2/neu mAb in wild-type CT-26 was only 0.45%. In vivo images were obtained and analyzed through $\gamma$-camera and an optical fluorescent modality, IVIS-200. $\gamma$-camera images showed that $^{131}I$ labeled anti-HER-2/neu mAb accumulated in HER-2/neu CT-26 tumors. Optical imaging based on near infrared fluorescence labeled anti-HER-2/neu mAb showed higher fluorescence intensities in HER-2/neu CT-26 tumors than in wild-type CT-26 tumors. Anti-HER-2/neu mAb was found to specifically bind to its receptor expressing tumor. Our study demonstrates that in vivo imaging technique is a useful method for the evaluation of an antibody's therapeutic and diagnostic potentials.

Three-dimensional analysis of dermal backflow in cancer-related lymphedema using photoacoustic lymphangiography

  • Oh, Anna;Kajita, Hiroki;Imanishi, Nobuaki;Sakuma, Hisashi;Takatsume, Yoshifumi;Okabe, Keisuke;Aiso, Sadakazu;Kishi, Kazuo
    • Archives of Plastic Surgery
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    • 제49권1호
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    • pp.99-107
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    • 2022
  • Background Dermal backflow (DBF), which refers to lymphatic reflux due to lymphatic valve insufficiency, is a diagnostic finding in lymphedema. However, the three-dimensional structure of DBF remains unknown. Photoacoustic lymphangiography (PAL) is a new technique that enables the visualization of the distribution of light-absorbing molecules, such as hemoglobin or indocyanine green (ICG), and can provide three-dimensional images of superficial lymphatic vessels and the venous system. This study reports the use of PAL to visualize DBF structures in the extremities of patients with lymphedema after cancer surgery. Methods Patients with a clinical or lymphographic diagnosis of lymphedema who previously underwent surgery for cancer at one of two participating hospitals were included in this study. PAL was performed using the PAI-05 system. ICG was administered subcutaneously in the affected hand or foot, and ICG fluorescence lymphography was performed using a near-infrared camera system prior to PAL. Results Between April 2018 and January 2019, 21 patients were enrolled and examined using PAL. The DBF was composed of dense, interconnecting, three-dimensional lymphatic vessels. It was classified into three patterns according to the composition of the lymphatic vessels: a linear structure of lymphatic collectors (pattern 1), a network of lymphatic capillaries and lymphatic collectors in an underlying layer (pattern 2), and lymphatic capillaries and precollectors with no lymphatic collectors (pattern 3). Conclusions PAL showed the structure of DBF more precisely than ICG fluorescence lymphography. The use of PAL to visualize DBF assists in understanding the pathophysiology and assessing the severity of cancer-related lymphedema.