• 한국약용작물학회지
• /
• 제20권4호
• /
• pp.222-230
• /
• 2012

We evaluated the inhibitory effects of extracts and components of Geranium thunbergii on aldose reductase (AR) and galactitol formation in rat lenses with high levels of galactose as a part of our ongoing search of natural sources for therapeutic and preventive agents for diabetic complications. The inhibitory effects of water, methanol and ethanol extracts of G. thunbergii on rat lens AR (RLAR) were determined. Comparing inhibitory effects of various solvent extracts, ethanol extract showed RLAR inhibitory activity ($IC_{50}$ values, 5.24 and $6.39{\mu}g/m{\ell}$, respectively). The ethanol extract was fractionated to chloroform, ethyl acetate and water. Of these, the ethyl acetate fraction from ethanol extract of G. thunbergii exhibited RLAR inhibitory activity ($IC_{50}$ value, $2.64{\mu}g/m{\ell}$). In order to identify the bioactive components of ethyl acetate soluble fraction of ethanol extract from G. thunbergii, eight compounds, namely gallic acid (1), protocatechuic acid (2), p-hydroxybenzoic acid (3), brevifolin carboxylic acid (4), geraniin (5), ellagic acid (6), kaempferol-3-O-arabinofuranosyl-7-O-rhamnopyranoside (7), kaempferitrin (8) were isolated. The isolates were subjected to in vitro bioassays to evaluate their inhibitory activity on RLAR and galactitol formation in rat lenses. The ellagic tannins (5, 6) and flavonoid (7) exhibited strong inhibitory effects on RLAR. Also, these three compounds (5, 6 and 7) suppressed galactitol accumulation in rat lens under high galactose conditions, demonstrating the potential to prevent galactitol accumulation exo vivo. These results suggest that the extracts and components of G. thunbergii are a promising agent in the prevention or treatment of diabetic complications.

• 한국자원식물학회지
• /
• 제30권1호
• /
• pp.17-21
• /
• 2017

AChE 억제제는 알츠하이머 질환 치료에 이용될 수 있으므로, 본 연구는 더위지기 정유로부터 AChE 활성성분을 탐색하기 위하여 수행한 것이다. 더위지기로부터 얻은 정유를 GC-MS로 분석했을 때 camphor가 29.8%, borneol이 28.0%, eucalyptol이 5.81%, coumarin이 5.49%의 피크 면적 비율을 보였다. 이 중 camphor, borneol, coumarin을 사용하여 Anti-AChE 활성 검색을 수행하였다. 그 결과, $0.298mg/m{\ell}$, coumarin은 $0.236mg/m{\ell}$의 $IC_{50}$ 값을 나타내었다. 이러한 결과는 coumarin이 anti-AChE 활성을 나타내는 활성물질임을 나타내는 것이다.

• 생약학회지
• /
• 제50권3호
• /
• pp.159-164
• /
• 2019

Zanthoxylum Peel is widely used as a common spice for a variety of foods. In the orient, it has also been used as traditional agents for treating diseases such as indigestion. Recently, Zanthoxylum Peel has been reported to have anti-cancer activity, anti-microbial activity, and anti-inflammatory activity. Chemical components are known sanshool compounds and xanthoxylin. In this study, we were carried out to investigate the constituents of inhibiting a drug metabolizing enzyme CYP3A4 from Zanthoxylum Peel. CYP3A4 is known as an enzyme involved in drug metabolism as monooxygenase containing the heme. As a result of experiment, we found that bergapten ($IC_{50}=18.21{\mu}M$) and quercetin ($IC_{50}=17.27{\mu}M$) isolated from EtOAc extract of Zanthoxylum Peel showed remarkable CYP3A4-inhibiting activities. Structures of the isolated active compounds were established by chemical and spectroscopic means.

• 전자공학회논문지SC
• /
• 제43권6호
• /
• pp.48-60
• /
• 2006

본 논문은 CMOS OTA를 이용한 3 개의 PWM 변조기를 제안한다. 이들은 램프 적분기와 전류로 임계전압은 조정할 수 있는 슈미트 트리거로 구성되었다. 개별 소자를 사용해 만든 원형회로는 제안된 PWM 회로들의 시비율이 선형적으로 제어될 수 있음을 보여준다. 제안된 변조기들은 구조가 간단하기 때문에 모노리식 IC로 쉽게 제작할 수 있다.

• Journal of information and communication convergence engineering
• /
• 제15권2호
• /
• pp.117-122
• /
• 2017

Three-dimensional integrated circuits (3D ICs), starting with memory cubes, have entered the mainstream recently. The benefits many predicted in the past are indeed delivered, including higher memory bandwidth, smaller form factor, and lower energy. However, 3D ICs have yet to find their deployment in aerospace applications. In this paper we first present key design tools and methodologies for high performance, low power, and reliable 3D ICs that mainly target terrestrial applications. Next, we discuss research needs to extend their capabilities to ensure reliable operations under the harsh space environments. We first present a design methodology that performs fine-grained partitioning of functional modules in 3D ICs for power reduction. Next, we discuss our multi-physics reliability analysis tool that identifies thermal and mechanical reliability trouble spots in the given 3D IC layouts. Our tools will help aerospace electronics designers to improve the reliability of these 3D IC components while not degrading their energy benefits.

• Natural Product Sciences
• /
• 제13권2호
• /
• pp.135-139
• /
• 2007

Four anthocyanins were isolated from the acidic alcoholic extract of Syzygium cumini fruits growing in Egypt: Pelargonidin-3-O-glucoside, pelargonidin-3,5-O-diglucoside, cyanidin-3-O-malonyl glucoside, and delphenidin-3-O-glucoside. They were identified by the chromatographic, TLC and PC, and spectral analyses, UV, $^1$H-NMR and FAB/MS. The fruits were found to contain 0.03 gm % anthocyanins calculated on fresh weight basis calculated by spectrophotometric assay. Cytotoxic activity of total alcoholic extract of the fruits was performed against several types of tumor cell lines using the SRB assay. The tested extract exhibited significant cytotoxic activity for MCF7 (breast carcinoma cell line) (IC$_{50}$= 5.9 ${\mu}$g/mL), while the IC$_{50}$ was > 10 ${\mu}$g/mL for both Hela (Cervix carcinoma cell line), HEPG2 (liver carcinoma cell line), H460 (Lung carcinoma cell line) and U251 (Brain carcinoma cell line).

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
• /
• pp.85-85
• /
• 2003

This study has been undertaken to increase availability of native camellia in Jeonnam as a medicinal resource and to isolate the effective components from them. Multidrug resistance(MDR) by tumor cells is a major obstacle to successful cancer chemotherapy. We report that the crude extracts of camellia flowers, leaves has a chemosensitizing effect that can reverse Pgp-mediated MDR by increasing the intracellular accumulation of drugs. The cytotoxic and chemosensitizing effects of MeOH extract from 12 spp. citrus fruits on the AML-2/D100 were determined using MTT assay. Chemosensitizing effects was screened in the presence of vincristine, a good substrate of Pgp. IC$\sub$50/ for extracts in AML-2/WT was found to be 65∼350$\mu\textrm{g}$/$m\ell$ whereas the range of its mean IC$\sub$50/ value in Pgp-overexpressing cells (AML-2/Dl00) in the presence of vincristine was 90∼400$\mu\textrm{g}$/$m\ell$. Of the extracts tested, mature leaf extract displayed the most potent chemosensitizing effect［IC$\sub$50/;100 $\mu\textrm{g}$/$m\ell$, CR;1.06, RF;2.97 in the presence of VCR］. This indicates that the toxicity (IC$\sub$50/;288.89$\mu\textrm{g}$/$m\ell$) of mature leaf extract is minimal at concentrations required for a complete reversal of the drug resistance. Also, this result indicates that crude extracts of camellia mature leaves would contain some principles which have chemosensitizing activity.

• 인터넷정보학회논문지
• /
• 제21권2호
• /
• pp.109-119
• /
• 2020

FPGA는 초기 제작 후 다시 설계 할 수 있는 반도체로 신호 처리, 자동차 산업, 국방 및 군사 시스템 등과 같은 다양한 임베디드 시스템 분야에서 사용된다. 하지만 하드웨어 설계의 복잡성이 증가하고 설계 및 제조 과정이 세계화됨에 따라 하드웨어에 삽입되는 하드웨어 악성기능에 대한 우려가 커져가고 있다. 이러한 위협에 대응하기 위해 많은 탐지 방법들이 제시되었지만, 기존 방법 대부분은 IC칩을 대상으로 하고 있어 IC칩과 구성요소가 다른 FPGA에 적용하기 어렵다. 또한 FPGA 칩을 대상으로 하는 하드웨어 악성기능탐지 연구는 거의 이루어지지 않고 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 FPGA의 LUT-level netlist에서 나타나는 하드웨어 악성기능의 정적인 특징을 기계학습을 통해 학습하여 하드웨어 악성기능을 탐지하는 방법을 제시한다.

• 한국자원식물학회지
• /
• 제37권2호
• /
• pp.110-119
• /
• 2024

본 연구는 꼬리진달래의 자원식물 개발을 위한 정보를 제공하고자 수행되었다. 꼬리진달래 신초 추출물의 폴리페놀 프로파일링을 통해 유용성분을 선발하고, 추출용매에 따른 유용성분 함량과 항산화 활성을 비교하였다. 꼬리진달래 신초 추출물에서 37개의 폴리페놀 화합물을 확인하였으며, chlorogenic acid, astragalin, myricetin, afzelin의 추출용매별 함량을 비교한 결과, chlorogenic acid의 함량은 에탄올 추출물에서 6.57±0.12 mg/g이었고, astragalin의 함량은 에탄올 추출물에서 2.29±0.02 mg/g, myricetin의 함량은 메탄올 추출물에서 4.77±0.06 mg/g, afzelin의 함량은 메탄올 추출물에서 0.10±0.01 mg/g이었다. 꼬리진달래 에탄올 추출물의 총 폴리페놀 함량은 80.01±2.36 mg/g, 총 플라보노이드 함량은 78.08±3.44 mg/g이었다. 또한 꼬리진달래 메탄올 추출물의 DPPH radical 소거활성 IC₅₀값은 943.57±10.68 mg/L였으며, ABTS radical 소거활성 IC₅₀은 641.60±7.58 mg/L였다. 꼬리진달래는 유기용매 추출 시 유용성분과 항산화 활성이 높았고, 동일 속의 종들과 비교하여 높은 함량의 chlorogenic acid, astragalin, myricetin, afzelin을 함유하고 있어 향후 건강기능성 소재로의 개발이 가능할 것으로 판단된다.

• 대한기계학회논문집A
• /
• 제24권12호
• /
• pp.2995-3002
• /
• 2000

The remaining life estimation for the aged components in power plants as well as chemical plants are very important beacuse mechanical properties of the components are degraded with time of service exposure in high temperature. Since it is difficult to take specimens from the operating components to evaluate mechanical properties of components nondestructive techniques are needed to estimate the degradation. In this study, test materials with 4 different degradation levels were prepared by isothermal aging heat treatment at 630$\^{C}$. And the DC potential drop method and destructive methods such as tensile, K(sub)IC and hardness tests were used in order to evaluate the degradation of 1-Cr-1Mo-0.25V steels. The objective of this study is to investigate the possibility of the application of DCPD method to estimated the material degradation, and to analyse the relationship between the electrical relationship between the electrical resistivity and the degree material degradation.