• Biomolecules & Therapeutics
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• 제13권1호
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• pp.26-31
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• 2005

The present study examined effects of a water-soluble fraction from mulberry leaves (ML water fraction) on the circulatory and autonomic nervous systems, which were compared with those of acetylcholine (ACh) used as a reference drug in order to elucidate its mechanism of action. Intravenous administration of ACh or a ML water fraction produced temporary depressor and tachycardiac responses in a dose-dependent manner in unrestrained, conscious Sprague-Dawley rats. The systemic hemodynamic effects of ACh and a ML water fraction were almost completely blocked by pretreatment with atropine, a muscarinic antagonist. The depressor responses to ACh and a ML water fraction were slightly enhanced and prolonged by pretreatment with neostigmine, an anticholinesterase, whereas the tachycardiac responses were remarkably blocked by pretreatment with pentolinium, a ganglionic blocking agent. In vitro experiments using the ileum isolated from rats showed that ACh and a ML water fraction increased ileal contractility in a dose-dependent manner. The increases in ileal contractility were also completely abolished in the presence of atropine. Finally, the specific binding of [$^3H$]quinuclidinyl benzilate, a muscarinic antagonist, to rat cortical synaptic membranes was inhibited by a ML water fraction in a concentration-dependent manner with an IC$_{50}$ value of 9.5 mg/ml. The results suggest that the effects of a ML water fraction are mediated through direct stimulation of muscarinic cholinergic receptors by unknown cholinomimetic substance(s) contained in that fraction.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.379-386
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• 2024

Basophils and mast cells are specialized effector cells in allergic reactions. Haliotis discus hannai (abalone), is valuable seafood. Abalone male viscera, which has a brownish color and has not been previously reported to show anti-allergic activities, was extracted with acetone. Six different acetone/hexane fractions (0, 10, 20, 30, 40, and 100%) were obtained using a silica column via β-hexosaminidase release inhibitory activity-guided selection in phorbol myristate acetate and a calcium ionophore, A23187 (PMACI)-induced human basophils, KU812F cells. The 40% acetone/hexane fraction (A40) exhibited the strongest inhibition of PMACI-induced-β-hexosaminidase release. This fraction dose-dependently inhibited reactive oxygen species (ROS) production and calcium mobilization without cytotoxicity. Western blot analysis revealed that A40 down-regulated PMACI-induced MAPK (ERK 1/2, p-38, and JNK) phosphorylation, and the NF-κB translocation from the cytosol to membrane. Moreover, A40 inhibited PMACI-induced interleukin (IL)-1β, IL-6, and IL-8 production. Anti-allergic activities of A40 were confirmed based on inhibitory effects on IL-4 and tumor necrosis factor alpha (TNF-α) production in compound (com) 48/80-induced rat basophilic leukemia (RBL)-2H3 cells. A40 inhibited β-hexosaminidase release and cytokine production such as IL-4 and TNF-α produced by com 48/80-stimulated RBL-2H3 cells. Furthermore, it's fraction attenuated the IgE/DNP-induced passive cutaneous anaphylaxis (PCA) reaction in the ears of BALB/c mice. Our results suggest that abalone contains the active fraction, A40 is a potent therapeutic and functional material to treat allergic diseases.

• Fisheries and Aquatic Sciences
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• 제16권1호
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• pp.1-5
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• 2013

To assess the feasibility of phlorotannins from Eisenia bicyclis as cancer chemopreventative agents, we tested whether they induced quinone reductase (QR) in Hepa1c1c7 cells. The ethyl acetate (EtOAc) soluble fraction obtained from E. bicyclis exhibited a QR induction activity in Hepa1c1c7 cells. Successive column chromatography of the active EtOAc fraction resulted in the isolation of four phlorotannins. Their structures were elucidated using one- and two-dimensional nuclear magnetic resonance spectroscopic techniques and characterized as phloroglucinol (1), dioxinodehydroeckol (2), dieckol (3), and fucofuroeckol-A (4). Among these compounds, fucofuroeckol-A (4) showed moderate QR induction activity, and dioxinodehydroeckol (2) exhibited potent QR induction potency with $2.05{\pm}0.04$ fold induction at a concentration of $50{\mu}M$ compared to the dimethyl sulfoxide solvent-treated control cells. However, phloroglucinol (1) and dieckol (3) exerted no detectable QR induction activity in Hepa1c1c7 cells. These results suggest that dioxinodehydroeckol could serve as a useful cancer chemopreventive chemical.

• 한국표면공학회지
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• 제41권6호
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• pp.301-307
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• 2008

In this paper, nanocrystallization of CuNiTiZr bulk metallic glass (BMG) subjecting to a kinetic spraying, dependent on impact velocity, was investigated by numerical and experimental approaches. The crystallization fraction and nucleation activation energy of initial feedstock and as-deposited coating were estimated by DSC and Kissinger method, respectively. The results of numerical modeling and experiment showed that the crystalline fraction and nucleation activation energy in BMG coatings were depended on kinetic energy of incident particle. Upon impact, the conversion of particle kinetic energy leads to not only decreasing free energy barrier but also increasing the driving force for an amorphous to crystalline phase transformation. The nanocrystallization of BMGs is associated with the strain energy delivered by a plastic deformation with a high strain rate.

• 대한수학교육학회지:수학교육학연구
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• 제23권1호
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• pp.17-35
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• 2013

본 연구에서는 초 중등 수학교사의 전문성을 신장하기 위해, 문장제 상황을 바탕으로, 정수를 대상으로 하는 나눗셈 알고리즘과 유클리드 알고리즘을 분수(유리수)를 대상으로 하는 나눗셈 알고리즘과 유클리드 알고리즘으로의 확장에 대해 다룬다. 분수 나눗셈의 문장제 상황에 나타난 이산적 환경과 연속적 환경 및 등분제와 포함제에 따라 '나눈다'는 개념을 두 유형으로 분류하였다. 하나는 유리수체에서 현대대수학 관점에서 다루어지는 대수적 개념이며, 다른 하나는 몫과 나머지가 동반된 정수 나눗셈 알고리즘을 유리수 나눗셈 알고리즘으로 일반화하는 개념이다. 후자의 개념을 중심으로 학교수학에서 다루어지거나 다룰 수 있는 문제 상황을 제시하며, 분수를 대상으로 하는 나눗셈 알고리즘, 최대공약수와 최소공배수, 유클리드 알고리즘에 관해 논의한다.

• 한국응용과학기술학회지
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• 제38권1호
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• pp.118-125
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• 2021

본 연구에서 사용된 와송(Orostachys japonica A. Berger)은 암 치료를 위한 민간요법으로 오랫동안 사용되어 온 약초이다. 본 연구에서는 와송(Orostachys japonica A. Berger) 에틸아세테이트 분획물의 항산화 효능 활성에 대하여 실험한 결과를 보고한다. 와송(Orostachys japonica A. Berger) 에틸아세테이트 분획물의 항산화 효능은 0.10 mg/mL 농도에서 78.54%의 DPPH 라디칼 소거활성을 보였고, 73.48%의 ABTS+ 라디칼 소거활성을 나타내어 항산화 효과가 있는 것을 확인하였다. 또한 대체실험동물 모델인 제브라피쉬를 이용한 독성실험 결과에서는 모든 농도에서 100%의 배아 생존율을 보이고 응고 또는 부화지연을 관찰할 수 없어 독성이 없는 것으로 나타났으며, UV-B조사에 의해 유도된 ROS생성은 와송 에틸아세테이트 분획물을 처리한 모든 larvae에서 전체적으로 형광강도가 감소하였다. 특히 3 ㎍/mL 농도에서 양성대조군 대비 35.7%의 감소율을 보여 효과적으로 ROS 생성을 억제하였음을 확인하였다. 위와 같은 결과로 미루어보아, 와송 에틸아세테이트 분획물은 천연 항산화제로서 화장품 분야에서 응용 가능성이 있을 것으로 기대한다.

• 열처리공학회지
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• 제14권4호
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• pp.205-211
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• 2001

The characteristics of super duplex stainless steel were investigated on its fibrous structure and dispersed structure. These structures consist of various volume fractions and distributions of the austenite phase that were obtained by changing the heat treatment temperature and cycle. The fibrous structure had higher austenite volume fraction than dispersed structure on the same temperature. As the austenite volume fraction increased in both structures, tensile strength and elongation increased, but hardness decreased. Fatigue life of fibrous structure parallel to rolling direction was shorter than that of perpendicular to rolling direction. Fatigue life of dispersed structure was longer than parallel fibrous structure, and shorter than perpendicular fibrous structure. Fatigue crack propagation rate of fibrous structure was faster than that of dispersed structure.

• 동의생리병리학회지
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• 제19권1호
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• pp.179-183
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• 2005

Recent interest in the possible protective effects of dietary antioxidant compounds against human degenerative disease has prompted investigation of foods such as blueberries, which have a high antioxidant capacity. This study was performed to determine the antioxidative activity of methanol extract and solvent fractions from blueberry. Blueberry was extracted with methanol and then fractionated with n-hexane, EtOAc, BuOH and water to get active fractions. And their antioxidant capacities in each fraction were determined by using the DPPH and FRAP assay, and tyrosinase inhibitor. Ethyl acetate fraction of blueberry exhibited antioxidant capacity.

• Korean Journal of Radiology
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• 제22권10호
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• pp.1671-1679
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• 2021

Objective: We quantitatively measured the fat fraction (FF) in the vertebrae of patients with ankylosing spondylitis (AS) using magnetic resonance imaging (MRI) and investigated the role of FF as an indicator of both active inflammation and chronicity. Materials and Methods: A total of 52 patients with AS who underwent spinal MRI were retrospectively evaluated. The FF values of the anterosuperior and anteroinferior corners of the bone marrow in the L1-S1 spine were assessed using the modified Dixon technique. AS activity was measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), AS Disease Activity Score (ASDAS), and serum inflammatory marker levels. AS disease chronicity was assessed by AS disease duration and the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Univariable and multivariable regression analyses were conducted to investigate the correlation between FF and other clinical characteristics. Results: The mean FF ± standard deviation of the total lumbar spine was 43.0% ± 11.3%. At univariable analysis, spinal FF showed significant negative correlation with BASDAI (β = -0.474, p = 0.002) and ASDAS with C-reactive protein (ASDAS-CRP; β = -0.478, p = 0.002) and a significant positive correlation with AS disease duration (β = 0.440, p = 0.001). After adjusting for patient age, sex, and total mSASSS score, spinal FF remained significantly negatively correlated with BASDAI (β = -0.543, p < 0.001), ASDAS-CRP (β = -0.568, p < 0.001), and ASDAS with erythrocyte sedimentation rate (β = -0.533, p = 0.001). Spinal FF was significantly lower in patients with very high disease activity (ASDAS-CRP > 3.5) than in those with only high disease activity (2.1 ≤ ASDAS-CRP ≤ 3.5) (p = 0.010). Conclusion: Spinal FF may help assess both AS disease activity and chronicity.

• Applied Biological Chemistry
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• 제43권2호
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• pp.81-85
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• 2000

미생물로부터 고분자 물질을 생산하여 기능성 식품보조제로 사용하기 위한 일환으로 고점성의 biopolymer를 생산하는 균주를 분리하고 이 분리균에 대한 분류학적 성질 및 생성 biopolymer의 이화학적 성질을 조사하였다. 분리 균주는 Bacillus coagulans로 동정되었으며 Bacillus cuagulans CE-74라 명명하었다. Acetone과 ethanol 처리를 하여 crude biopolymer를 얻었으며, crude biopolymer를 DEAE-cellulose ion exchange cromatography, Sephadex G-100 및 Sepharose CL-2B를 사용하여 fraction I과 fraction II 두 분획을 분리 정제하였다. 분리된 분획의 구성 성분을 분석한 결과 당 성분은 검출되지 않았고, 아미노산 분석을 실시한 결과 fraction I은 lysine만으로 구성되어 있었으며, fraction II는 glutamic acid만이 검출되었다. 분자량은 fraction I은 약 42kD, fraction II는 약 $1.6{\times}10^3\;KD$로 추정되었다.