• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.220-220
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• 2018

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.184-188
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• 2022

• BMB Reports
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• v.41 no.2
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• pp.126-131
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• 2008

The folding of aptamer immobilized on an Au electrode was successfully detected using label-free electrochemical methods. A thrombin binding DNA aptamer was used as a model system in the presence of various monovalent cations. Impedance spectra showed that the extent to which monovalent cations assist in folding of aptamer is ordered as $K^+$ > $NH_4^+$ > $Na^+$ > $Cs^+$. Our XPS analysis also showed that $K^+$ and $NH_4^+$ caused a conformational change of the aptamer in which it forms a stable complex with these monovalent ions. Impedance results for the interaction between aptamer and thrombin indicated that thrombin interacts more with folded aptamer than with unfolded aptamer. The EQCM technique provided a quantitative analysis of these results. In particular, the present impedance results showed that thrombin participates a folding of aptamer to some extent, and XPS analysis confirmed that thrombin stabilizes and induces the folding of aptamer.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1124-1131
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• 2016

In this study, the global proteome of the IPEC-J2 cell line was evaluated using ultra-high performance liquid chromatography coupled to a quadrupole Q Exactive^™ Orbitrap mass spectrometer. Proteins were isolated from highly confluent IPEC-J2 cells in biological replicates and analyzed by label-free mass spectrometry prior to matching against a porcine genomic dataset. The results identified 1,517 proteins, accounting for 7.35% of all genes in the porcine genome. The highly abundant proteins detected, such as actin, annexin A2, and AHNAK nucleoprotein, are involved in structural integrity, signaling mechanisms, and cellular homeostasis. The high abundance of heat shock proteins indicated their significance in cellular defenses, barrier function, and gut homeostasis. Pathway analysis and annotation using the Kyoto Encyclopedia of Genes and Genomes database resulted in a putative protein network map of the regulation of immunological responses and structural integrity in the cell line. The comprehensive proteome analysis of IPEC-J2 cells provides fundamental insights into overall protein expression and pathway dynamics that might be useful in cell adhesion studies and immunological applications.

• Current Optics and Photonics
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• v.4 no.4
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• pp.368-372
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• 2020

We report the terahertz time-domain spectroscopy (THz-TDS) of transdermal drug delivery in human skin. The time evolution of transdermal nicotine delivery in nicotine patches was assessed by detecting the transmission coefficient of sub-picosecond THz pulses and using a semi-analytic model based on the single-layer effective medium approximation. Using commercial nicotine patches (Nicoderm CQ^®, 7 mg/24 h), THz transmission coefficients were measured to quantitatively analyze the cumulative amounts of nicotine released from the patches in the absence of their detailed specifications, including multilayer structures and optical properties at THz frequencies. The results agreed well with measurements by conventional in vitro and in vivo methods, using a diffusion cell with high-performance liquid chromatography and blood sampling respectively. Our study revealed the ability of the THz-TDS method to be an effective alternative to existing methods for noninvasive and label-free assessments of transdermal drug delivery, showing its high promise for biomedical, pharmaceutical, and cosmetic applications.

• Molecules and Cells
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• v.44 no.11
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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 the Korean Society of Visualization
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• v.20 no.3
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• pp.19-26
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• 2022

In droplet microfluidics, precise droplet manipulation is required in numerous applications. This study presents ultrasonic surface acoustic wave (USAW)-based microfluidic device for label-free droplet separation based on size. The proposed device is composed of a slanted-finger interdigital transducer on a piezoelectric substrate and a polydimethylsiloxane microchannel placed on the substrate. The microchannel is aligned in the cross-type configuration where the USAWs propagate in a perpendicular direction to the flow in the microchannel. When droplets are exposed to an acoustic field, they experience the USAW-induced acoustic radiation force (ARF), whose magnitude varies depending on the droplet size. We modeled the USAW-induced ARF based on ray acoustics and conducted a series of experiments to separate different-sized droplets. We found that the experimental results were in good agreement with the theoretical estimation. We believe that the proposed method will serve as a promising tool for size-based droplet separation in a label-free manner.

• Annual Conference on Human and Language Technology
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• 2023.10a
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• pp.664-671
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• 2023

최근 다양한 거대 언어모델(Large Language Model)들이 개발되면서 프롬프트 엔지니어링의 대한 다양한 연구가 진행되고 있다. 본 논문에서는 퓨삿 학습 환경에서 개체명 인식의 성능을 높이기 위해서 제안된 템플릿이 필요 없는 프롬프트 튜닝(Template-free Prompt Tuning) 방법을 이용하고, 이 방법에서 사용된 라벨 단어 집합 생성 방법에 Maximal Marginal Relevance 알고리즘을 적용하여 해당 개체명에 대해 보다 다양하고 구체적인 라벨 단어 집합을 생성하도록 개선하였다. 실험 결과, 'LOC' 타입을 제외한 나머지 개체명 타입에서 'PER' 타입은 0.60%p, 'ORG' 타입은 4.98%p, 'MISC' 타입은 1.38%p 성능이 향상되었고, 전체 개체명 인식 성능은 1.26%p 향상되었다. 이를 통해 본 논문에서 제안한 라벨 단어 집합 생성 기법이 개체명 인식 성능 향상에 도움이 됨을 보였다.

• Analytical Science and Technology
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• v.27 no.3
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• pp.121-139
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• 2014

In this review, we will discuss aptamer technologies including in vitro selection, signal transduction mechanisms, and designing aptamers and aptazyme for label-free biosensors and catalysts. Dye-displacement, a typical label-less method, is described here which allows avoiding relatively complex labeling steps and extending this application to any aptamers without specific conformational changes, in a more simple, sensitive and cost effective way. We will also describe most recent and advanced technologies of signaling aptamer and aptazyme for the various analytical and clinical applications. Quantum dot biosensor (QDB) is explained in detail covering designing and adaptations for multiplexed protein detection. Application to aptamer array utilizing self-assembled signaling aptamer DNA tile and the novel methods that can directly select smart aptamer or aptazyme experimentally and computationally will also be finally discussed, respectively.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.1
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• pp.8-16
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• 2014

We consider the visual barcode recognition problem in a noisy video data setup. Unlike most existing single-frame recognizers that require considerable user effort to acquire clean, motionless and blur-free barcode signals, we eliminate such extra human efforts by proposing a robust video-based barcode recognition algorithm. We deal with a sequence of noisy blurred barcode image frames by posing it as an online filtering problem. In the proposed dynamic recognition model, at each frame we infer the blur level of the frame as well as the digit class label. In contrast to a frame-by-frame based approach with heuristic majority voting scheme, the class labels and frame-wise noise levels are propagated along the frame sequences in our model, and hence we exploit all cues from noisy frames that are potentially useful for predicting the barcode label in a probabilistically reasonable sense. We also suggest a visual barcode tracking approach that efficiently localizes barcode areas in video frames. The effectiveness of the proposed approaches is demonstrated empirically on both synthetic and real data setup.