• Journal of Gastric Cancer
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• 제12권1호
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• pp.7-12
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• 2012

More than ten years have passed since the sentinel node (SN) concept for gastric cancer surgery was first discussed. Less invasive modified surgical approaches based on the SN concept have already been put into practice for malignant melanoma and breast cancer, however the SN concept is not yet placed in a standard position in gastric cancer surgery even after two multi-institutional prospective clinical trials, the Japan Clinical Oncology Group trial (JCOG0302) and the Japanese Society for Sentinel Node Navigation Surgery (SNNS) trial. What is the problem in the clinical application of the SN concept to gastric cancer surgery? There is no doubt that we need reliable indicator(s) to determine with certainty the absence of metastasis in the lymph nodes in order to avoid unnecessary lymphadenectomy. There are several matters of debate in performing the actual procedure, such as the type of tracer, the site of injection, how to detect and harvest, how to detect metastases of SNs, and learning period. These issues have to be addressed further to establish the most suitable procedure. Novel technologies such as indocyanine green (ICG) fluorescence imaging and one-step nucleic acid amplification (OSNA) may overcome the current difficulties. Once we know what the problems are and how to tackle them, we can pursue the goal.

• Macromolecular Research
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• 제14권6호
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• pp.646-653
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• 2006

Highly hydrophilic, uniform, superparamagnetic and nontoxic maltotrionic acid (MA)-coated magnetite nano-particles (MAM) were prepared and characterized by TEM, DLS, XRD and VSM. MA was used to improve the biocompatibility, monodispersity and non-specific intracellular uptake of nanoparticles. Folic acid (FA) was subsequently conjugated to the MAM to preferentially target KB cells (cancer cells) that have folate receptors expressed on their surfaces and to facilitate nanoparticles in their transit across the cell membrane. Finally, fluorescence isothiocyanate (FITC) was added to the nanoparticles to visualize the nanoparticle internalization into KB cells. After the cells were cultured in a media containing the MAM and MAM-folate conjugate (FAMAM), the results of fluorescence and confocal microscopy showed that both types of nanoparticles were internalized into the cells. Nevertheless, the amount of FAMAM uptake was higher than that of MAM. This result indicated that nanoparticles modified with MA and FA could be used to facilitate the nanoparticle uptake to specific KB cells (cancer cells) for molecular imaging.

• KSBB Journal
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• 제27권5호
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• pp.295-300
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• 2012

Matured dendritic cells (DCs) begin migration with their release from the bone marrow (BM) into the blood and subsequent traffic into peripheral lymphoid and non-lymphoid tissues. Throughout this long movement, migrating DCs must apply specialized skills to reach their target destination. Non-invasive in vivo cell-tracking techniques are necessary to advance immune cell-based therapies. In this study, we used a DiD cell-tracking solution for in vivo dendritic cell tracking in naive mice. We tracked DiD (non-invasive fluorescence dye)-labeled mature dendritic cells using the Near Infrared (NIR) imaging system in normal mice. We examined the immunophenotype of DiD-labeled cells compared with non-labelled mature DCs, and obtained time-serial images of NIR-DC trafficking after mouse footpad injection. In conclusion, we confirmed that DiD-labeled DCs migrated into the popliteal lymph node 24 h after the footpad injection. Here, these data suggested that the cell tracking system with the stable fluorescence dye DiD was useful as a cell tracking tool to advance dendritic cell-based immunotherapy.

• Molecules and Cells
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• 제23권2호
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• pp.170-174
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• 2007

High-throughput subcellular imaging is a powerful tool for investigating the function of genes. In order to identify novel regulators of apoptosis we transiently transfected HeLa cells with 938 hypothetical genes of unknown function, and captured their nuclear images with an automated fluorescence microscope. We selected genes that induced greater than 3-fold increase in the percentage of apoptotic nuclei compared with vector-transfected cells. The full-length genes C10orf61, MGC 26717, and FLJ13855 were identified as candidate proapoptotic genes, and their apoptotic effects were confirmed by DNA fragmentation ELISAs and Western blotting for caspase-7 and PARP. We conclude that a subcellular image-based apoptotic screen is useful for identifying genes with proapoptotic activity.

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.310-315
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• 2009

We report the fabrication of double clad fiber (DCF) and DCF coupler, suitable for fiber based imaging systems requiring the dual-channel transmission. Unlike the conventional DCF which uses silica for both cladding layers, the proposed DCF uses a low-index polymer for its outer-cladding layer coated over the conventional silica inner-cladding layer. The DCF is drawn with a conventional SMF preform but a low-index polymer coating is used for both jacket and outercladding of the fiber. To achieve the cladding mode coupling, a DCF coupler is fabricated by simply twisting two pieces of the proposed DCF after removing the polymer-coating at contacting regions. A cladding mode coupling ratio of 30% was achieved with a contact length of 16 cm. The proposed DCF and DCF coupler were employed in a composite optical coherence tomography (OCT) and fluorescence spectroscopy (FS) system, and both OCT images and FS signal from a plant tissue are measured simultaneously.

• Molecules and Cells
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• 제44권11호
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• pp.851-860
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• 2021

Label-free optical diffraction tomography (ODT), an imaging technology that does not require fluorescent labeling or other pre-processing, can overcome the limitations of conventional cell imaging technologies, such as fluorescence and electron microscopy. In this study, we used ODT to characterize the cellular organelles of three different stem cells-namely, human liver derived stem cell, human umbilical cord matrix derived mesenchymal stem cell, and human induced pluripotent stem cell-based on their refractive index and volume of organelles. The physical property of each stem cell was compared with that of fibroblast. Based on our findings, the characteristic physical properties of specific stem cells can be quantitatively distinguished based on their refractive index and volume of cellular organelles. Altogether, the method employed herein could aid in the distinction of living stem cells from normal cells without the use of fluorescence or specific biomarkers.

• Journal of Gastric Cancer
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• 제17권2호
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• pp.145-153
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• 2017

Purpose: Identification of the infrapyloric artery (IPA) type is a key component of pylorus-preserving gastrectomy. As the indocyanine green (ICG) fluorescence technique is known to help visualize blood vessels and flow during reconstruction, we speculated that this emerging technique would be helpful in identifying the IPA type. Materials and Methods: From August 2015 to February 2016, 20 patients who underwent robotic or laparoscopic gastrectomy were prospectively enrolled. After intravenous injection of approximately 3 mL of ICG (2.5 mg/mL), a near-infrared fluorescence apparatus was applied. The identified shape of the IPA was confirmed by examining the actual anatomy following infrapyloric dissection. Results: The mean interval time between ICG injection and visualization of the artery was 22.2 seconds (range, 14-30 seconds), and the mean duration of the arterial phase was 16.1 seconds (range, 9-30 seconds). The overall positive predictive value (PPV) of ICG fluorescence in identifying the IPA type was 80% (16/20). The IPA type was incorrectly predicted in four patients, all of whom were obese with a body mass index (BMI) of more than $25kg/m^2$. Conclusions: Our preliminary results indicate that intraoperative vascular imaging using the ICG fluorescence technique may be helpful for robotic or laparoscopic pylorus-preserving gastrectomy.

• ALGAE
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• 제25권3호
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• pp.133-140
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• 2010

Using chlorophyll fluorescence, the vertical migration of benthic diatoms responding to light intensity and affected by sediment grain size was studied. Minimal fluorescence ($F_o$) of surface sediment was measured by imaging pulse amplitude modulated (Imaging-PAM) fluorometer, and used to monitor diatom biomass variation in surface sediments. The test diatoms, Amphora coffeaeformis (C. Agardh) K$\ddot{u}$tzing and Cylindrotheca closterium (Ehrenberg) Reimann & Lewin, migrated to the sediment surface under irradiance from 50 to 500 ${\mu}mol$ photons $m^{-2}s^{-1}$. However, the diatoms exhibited no evident increase of surface biomass under dark conditions, and even showed slightly decrease of surface biomass under irradiances over 1,000 ${\mu}mol$ photons $m^{-2}s^{-1}$. The light intensity inducing the maximum surface migration of A. coffeaeformis was 100 ${\mu}mol$ photons $m^{-2}s^{-1}$, while the light intensity producing the same effect for C. closterium was 250 ${\mu}mol$ photons $m^{-2}s^{-1}$. C. closterium showed higher motility than A. coffeaeformis. Faster diatom surfacing was observed in larger grain size sediments (125-335 ${\mu}m$) than smaller ones (63-125 ${\mu}m$). This study confirmed the significant influence of light as a main triggering factor behind migration, indicated the distinct effect of different sediment grain size, and highlighted the species-specific migratory ability.

• 한국환경농학회지
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• 제39권2호
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• pp.138-141
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• 2020

BACKGROUND: Fresh weight is one of the major quality measurement factors in determining the quality of fresh fruits. A practical method has been developed for rapid and non-destructive measurement using the Chlorophyll Fluorescence Image (CFI) technique to estimate changes in fresh weight of post-harvest products. METHODS AND RESULTS: Kiwifruit (Actinidia deliciosa) was used and measured for the fresh weight and CFI under different temperature conditions at 0, 10, and 20℃, from 0 to 21 days after storage (DAS). We observed the fresh weight of kiwifruit and measured the surface image for determining F_v/F_m value in terms of maximum quantum yield on each day. To estimate freshness of kiwifruit we applied linear regression between the measured fruit weights and F_v/F_m values. Results showed that fruit weights were reduced by 4% at 0℃, 6% at 10℃, and 14% at 20℃ for 21 days, respectively. And also, the value of Fv/Fm was shown as decreasing trend at all temperature conditions, especially at 20 ℃. Fv/Fm values showed highly significant correlation (R²>0.9) with fresh weight of kiwifruit at all different storage temperatures. CONCLUSION: Thus, CFI technique can be useful to estimate the fresh weight of kiwifruit.

• 공업화학전망
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• 제22권6호
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• pp.41-58
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• 2019

다공성 실리콘 나노 입자는 약물 전달과 바이오이미징 등 의생명공학 분야에 다양하게 활용할 수 있는 가능성을 지닌 소재이다. 실리콘 원소 특유의 생분해성, 발광 효과, 다공성 구조 형성을 통한 약물 전달 기능에 이르는 다양한 특성으로 인해 미래 중개의학 플랫폼으로 각광 받고 있으며, 특히 바이오이미징 분야에서의 활용성이 매우 주목 받고 있다. 이에 대한 최신 연구 동향을 보고하고자, 다공성 실리콘 나노 입자의 제작 및 바이오이미징 응용 연구에 대한 성과를 소개한다. 바이오이미징을 위한 핵심 요소인 발광 특성(근적외선 방출, 마이크로 초 단위의 감쇄 시간 등)에 대한 논의를 바탕으로 최근 연구 성과 및 약물 전달 과정 모니터링 기능 등 다방면의 응용 가능성에 대한 방향을 소개한다. 실리콘 나노 입자의 제작 및 표면 화학 반응을 통한 기능성 제어, 이를 활용한 바이오이미징 연구 동향에 대한 전략도 광범위하게 제시하고자 한다.