• BMB Reports
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• 제53권7호
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• pp.349-356
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• 2020

Mass spectrometry (MS) is an ideal tool for analyzing multiple types of (bio)molecular information simultaneously in complex biological systems. In addition, MS provides structural information on targets, and can easily discriminate between true analytes and background. Therefore, imaging mass spectrometry (IMS) enables not only visualization of tissues to give positional information on targets but also allows for molecular analysis of targets by affording the molecular weights. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS is particularly effective and is generally used for IMS. However, the requirement for an organic matrix raises several limitations that get in the way of accurate and reliable images and hampers imaging of small molecules such as drugs and their metabolites. To overcome these problems, various organic matrix-free LDI IMS systems have been developed, mostly utilizing nanostructured surfaces and inorganic nanoparticles as an alternative to the organic matrix. This minireview highlights and focuses on the progress in organic matrix-free LDI IMS and briefly discusses the use of other IMS techniques such as desorption electrospray ionization, laser ablation electrospray ionization, and secondary ion mass spectrometry.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1933-1938
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• 2003

A covariance matrix is a tool that expresses odometry uncertainty of the wheeled mobile robot. The covariance matrix is a key factor in various localization algorithms such as Kalman filter, topological matching and so on. However it is not easy to acquire an accurate covariance matrix because we do not know the real states of the robot. Up to the authors knowledge, there seems to be no established result on the covariance matrix estimation for the odometry. In this paper, we propose a new method which can estimate the covariance matrix from empirical data. It is based on the PC-method and shows a good estimation ability. The experimental results validate the performance of the proposed method.

• Translational and Clinical Pharmacology
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• 제25권2호
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• pp.67-73
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• 2017

Glimepiride, a third generation sulfonylurea, is an antihyperglycemic agent widely used to treat type 2 diabetes mellitus. In this study, an untargeted urinary metabolomic analysis was performed to identify endogenous metabolites affected by glimepiride administration. Urine samples of twelve healthy male volunteers were collected before and after administration of 2 mg glimepiride. These samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and then subjected to multivariate data analysis including principal component analysis and orthogonal partial least squares discriminant analysis. Through this metabolomic profiling, we identified several endogenous metabolites such as adenosine 3', 5'-cyclic monophosphate (cAMP), quercetin, tyramine, and urocanic acid, which exhibit significant metabolomic changes between pre- and posturine samples. Among these, cAMP, which is known to be related to insulin secretion, was the most significantly altered metabolite following glimepiride administration. In addition, the pathway analysis showed that purine, tyrosine, and histidine metabolism was affected by pharmacological responses to glimepiride. Together, the results suggest that the pharmacometabolomic approach, based on LC-MS/MS, is useful in understanding the alterations in biochemical pathways associated with glimepiride action.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.74-74
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• 2020

Skin is continuously exposed to a variety of environmental stresses, including ultraviolet (UV) radiation. UVB is an inherent component of sunlight that crosses the epidermis and reaches the upper dermis, leading to increased oxidative stress, activation of inflammatory response and accumulation of DNA damage among other effects. In the present study, the anti-wrinkle mechanism of Acorus gramineus callus culture supernatant (GB-AGS-PSC) was elucidated in UVB treated HaCaT keratinocytes. GB-AGS-PSC prevented the matrix metalloprotease 1 (MMP-1), elastin, and pro-collagen product and cytotoxicity and SOD inhibition. Quantitative polymerase chain reaction showed that GB-AGS-PSC-treated cells displayed dose-dependent increase in messenger RNA expression levels of Aquaporin 3 (AQP3), Keratin 1(KRT1), fillagrin, and hyaluronan synthase-2 (HAS 2) and decreased expression levels of matrix metalloproteinase-3, -9, and -13 in UVB treated HaCaT keratinocytes. Additionally, GB-AGS-PSC suppressed TNF-α, IL-1β, and IL-8 product for inflammatory responses in UVB treated HaCaT keratinocytes. Therefore, GB-AGS-PSC may be useful as an anti-photoaging resource for the skin.

• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2293-2298
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• 2010

Focused electrospray (FES) deposition method is presented for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. FES ion optics consists of two cylindrical focusing electrodes capped with a truncated conical electrode through which an electrospray emitter passes along the cylindrical axis. A spray of charged droplets is focused onto a sample well on a MALDI target plate under atmospheric pressure. The shape and size distributions of matrix crystals are visualized by scanning electron microscope and the mass spectra are obtained by time-of-flight mass spectrometry. Angiotensin II, bradykinin, and substance P are used as test samples, while $\alpha$-cyano-4-hydroxycinnamic acid and dihydroxybenzoic acid are employed as matrices. FES of a sample/matrix mixture produces fine crystal grains on a 1-3 mm spot and reproducibly yields the mass spectra with little shot-to-shot and spot-to-spot variations. Although FES greatly stabilizes the signals, the space charge due to matrix ions limits the detection sensitivity of peptides. To avoid the space charge problem, we adopted a dual FES/FES mode, which separately deposits matrix and sample by FES in sequence. The dual FES/FES mode reaches the detection sensitivity of 0.88 amol, enabling ultrasensitive of peptides by homogeneously depositing matrix and sample under atmospheric pressure.

• Genomics & Informatics
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• 제17권2호
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• pp.18.1-18.10
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• 2019

Prediction of the relations among drug and other molecular or social entities is the main knowledge discovery pattern for the purpose of drug-related knowledge discovery. Computational approaches have combined the information from different sources and levels for drug-related knowledge discovery, which provides a sophisticated comprehension of the relationship among drugs, targets, diseases, and targeted genes, at the molecular level, or relationships among drugs, usage, side effect, safety, and user preference, at a social level. In this research, previous work from the BioNLP community and matrix or matrix decomposition was reviewed, compared, and concluded, and eventually, the BioNLP open-shared task was introduced as a promising case study representing this area.

• 분석과학
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• 제20권2호
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• pp.176-182
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• 2007

본 연구는 매트릭스형의 농약 활성물질을 포함하는 서방성 수분 인지제제 및 그의 제조방법에 관한 것이다. 산을 첨가한 커들란 용액에 망목구조를 가진 매트릭스가 형성되며 이 매트릭스에 열처리를 하게 되면 수용성이 없어진다. 본 매트릭스의 망목구조는 수분이 존재조건에서 열리며 건조조건에서는 다시 닫히게 된다. 그러므로 본 서방성 제형시스템에서는 수분이 있는 조건에서만 농약 활성물질이 제형에서 방출된다. 본 서방성 제제에 따른 구성을 이용하면 농약 활성물질의 효과 발현시기를 제어할 수 있고, 약해(藥害) 등의 발생을 경감시킬 수 있다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.485-485
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• 2005

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권6호
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• pp.510-522
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• 2005

To assess the clinical applicability of bio-artificial mucosa which was made with autologous oral keratinocytes and human acellular dermal matrix, the formation of basement membrane and stratification of oral keratinocytes were evaluated. Six New Zealand white rabbits (around 2kg in weight) were anesthetized and its buccal mucosa was harvested (1.0 $\times$ 0.5cm size). Oral keratinicytes were extracted and cultured primarily with the feeder layer of pretreated NIH J2 3T3 fibroblast. These confluent cells were innoculated on the human acellular dermal matrix and cultured in multiple layer by air-rafting method. After 3, 5, 7, 10, 14 days of culture, each cultured bio-artificial mucosa was investigated the number of epthelial layer of by H&E stain and toluidine blue stain. The immuhohistochemical methods were used to evaluate the cell division capacity, the formation of basement membrane, and it's property of specific cells (PCNA, cytokeratin 14, laminin). Transmission electromicroscopy was used for the attachment between cells and matrix with the number of hemidesmosome. In result, the numbers of layer of stratified growth of oral keratinocyte cultured on the human acellular dermal matrix and the number of hemidesomal attachment between epithelial cells and human acellular dermal matrix were similar to the layers of normal oral mucosa after 10 days of culture. The cell division rate, basement membrane formation and proliferation rate increased as culture period increased. With these results, bio-artificial mucosa with autologous oral epithelial cells cultured on the acellular dermal matrix had clinically adaptable properties after 10 days' culture and this new bio-artificial mucosa model with relatively short culture time can be expected clinical applicability.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2005년도 추계 학술발표대회 논문집
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• pp.78-79
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• 2005