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천연 식물 추출물에서 멜라닌생성 억제물질의 동정과 생화학적 특성
최우준,선일식,허용철,성낙도,박성우,김건우,최성운 한국과학수사학회 2010 과학수사학회지 Vol.4 No.2
본 연구에서는 (주)코스비전에서 분양받은 6가지의 에탄올 천연 추출물에 대한 화학적 구성을 GC/MS로 분석하였다. 주요 성분으로는 각 시료에서 공통적으로 Saturated fatty acid인 Palmitic acid와 Stearic acid, Unsaturated fatty acid인 Oleic acid, Sterol 중에서는 콜레스테롤(Cholest-5-en-3-ol), 시토스테롤(sitosterol), 캄페스테롤(campesterol), 스티그마스테롤(stigmasterol) 등이 검출되었다. 이 후 에탄올 천연 추출물은 티로지나아제(Tyrosinase) 활성억제 효과, B16 세포에서 멜라닌 생성억제 효과, 산화(oxdation)및 당화(glycation)억제 효과 등을 분석하여 멜라닌 억제에 관련된 생리활성을 알아보았다.
최우준 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.6
We present label-free phase imaging to differentiate human breast cancer cells for breast cancer diagnosis. Low-coherent quantitative phase microscopy (QPM) is exploited to provide speckle-free interference images of live cells adhered to a plate, from which the phase information of the individual cells can be extracted. The phase measurement performance of QPM is validated by the phase-derived optical thickness of a sub-wavelength featured sample, consistent with the results when using conventional atomic force microscopy (AFM). The phase sensitivity is recorded as $\sim$44 mrad, corresponding to $\sim$2.3 nm depth fluctuation during measurement. Phase-contrast imaging is performed with three breast epithelial cell lines: non-tumorous (MCF-10A), weakly malignant (MCF-7), and highly malignant (MDA-MB-231), which mimic an \textit{in vivo} environments in development of human breast cancer. Our results indicate that MCF-10A and MDA-MB-231 exhibited significantly lower phase-shifts than those of MCF-7, but no difference in phase was observed between MCF-10A and MDA-MB-231. We expect that the use of the QPM approach would be beneficial for clinicians to quantitatively evaluate the breast cancer states from the unmodified specimen of breast biopsy.
몇 가지 천연 추출물의 특정성분에 대한 동정과 Melanin 생성억제
최우준,이준희,허용철,박성우 한국과학수사학회 2012 과학수사학회지 Vol.6 No.4
독성의 한 가지 형태로 Melanin 색소의 생성을 저해하는 화합물을 탐색하기 위하여 해외 자생식물 추출물(1-6)을 대상으로 특정한 화합물(A-F)을 GC/MS로 동정하고 특이구조를 갖는 성분들을 선별하였다. 추출물과 선별한 화합물에 대하여 Tyrosinase 저해활성, B16 세포에서 멜라닌 생성 억제효과, 산화 및 당화 억제효과, 등을 분석한 결과, 추출물 2, 3, 5 및 6중에 함유된 2-Methoxy-4-vinylphenol (A)이 4가지 실험에서 모두 긍정적인 효과를 보였을 뿐 아니라, 가장 효과적인 Melanin 색소의 생성 저해제로 판단되었다. 그러나 물질안전 보건자료(MSDS)의 결과에 따르면 A를 포함하여 B, C 및 E은 눈에 대하여 심한 자극을 보이는 것으로 나타났다.
Barium 조영제의 농도 차이가 PET 검사에 미치는 영향
최우준,신상기,남기표,박순기,Choi, Woo-Joon,Shin, Sang-Ki,Nam, Ki-Pyo,Park, Soon-Ki 대한핵의학기술학회 2008 핵의학 기술 Vol.12 No.1
Purpose: The evaluation of SUV (Standardized Uptake Values) for quantitative analysis in PET exam is the most significant. In PET exam, we make attenuation correction images by using $^{68}Ge$, $^{137}Cs$ or CT data. At this time, a distorted attenuation map affects quantitative analysis. After the exam using barium-sulfate and high density of barium contrast make attenuation map distorted. And then it brings bed influences on SUV. The aim of this study is to verify the relationship between high density barium-sulfate and SUV in PET exam. Materials and Methods By using $^{18}F$-FDG, we made barium-sulfate powder, density of 0, 1.5, 3, 5, 10 and 15% respectively and acquired PET and PET/CT images per each density. And we examined SUV variations from PET and PET/CT images according to differences of barium's density. Moreover, we finally calculated SUV causing variations in HU (Hounsfield Units) values to justify whether the differences of barium density bring any changes in PET/CT exam. Results: From PET images acquired from transmission scan with $^{68}Ge$, we got SUV figures from 6.46 to 6.8 in barium density between 0 to 15 percent. On the other hand, In PET images acquired from Tx scan that using CT, SUV was 6.77 to 23.73, derived from the same barium density. And CT HU values range from 29 to 2004. Conclusion: PET images from Tx data using $^{68}Ge$ weren't affected by barium density and had no differences in SUV. But in the PET/CT images using CT Tx data, there's considerable variations in HU and SUV values according to a difference of barium density in HU values. To perform a precise examination, barium sulfate should be removed from a human body before performing a PET exam.
Resistor-Based Temperature Sensors: A Technical Review
이용태,최우준,채영철 한국과학기술원 반도체설계교육센터 2021 IDEC Journal of Integrated Circuits and Systems Vol.7 No.1
This paper presents a technical overview of recently developed resistor-based temperature sensors, which achieve high energy-efficiency and high resolution, simultaneously. Such sensors consist of silicided polysilicon resistors that have relatively high temperature coefficients (TCs), low 1/f noise, low supply dependency, and low stress sensitivity. Various design techniques of resistor-based sensors are compared and their performances are summarized.