• 생약학회지
• /
• 제21권2호
• /
• pp.121-125
• /
• 1990

Essential oil of the root of Angelica dahurica Benth et Hook(Umbelliferae) was investigated. Essential oil was obtained from the dried roots by steam distillation and fractionated by column chromatography. Each isolate or fraction was identified by GC, GC-MS and spectral analysis. It was found to contain eleven monoterpenes such as ${\alpha}-pinene(4.74%),\;campben, {\beta}-pinene,\;myrcene,\;{\alpha}-phellandrene,\;{\delta}-3-carene(39.4%),\;{\alpha}-terpinene,\;{\rho}-cymene,\;{\beta}-phellandrene,\;{\alpha}-terpinene,\;terpinolene\;and\;also\;found\;to\;contain\;4-vinylguaiacol,\;iso-elemicin,\;{\beta}-elemene$, caryophyllene, ligustilide, osthol and seven tentatively identified sesquiterpenes.

• 생약학회지
• /
• 제21권2호
• /
• pp.111-120
• /
• 1990

Five biflavones and sevenflavonolglycosideswereisolatedfromtheleaves of Ginkgo biloba. They were sciadopitysin(1), ginkgetin(2), isoginkgetin(3), bilobetin(4), amentoflavone(5), kaempferol 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](6), quercetin 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](8), rutinosides of kaempferol(7), isorhamnetin(9), quercetin(10), laricitrin(11), and kaempferol 3-O-($2',6'-{\alpha}-_L-dirhamnopyranosyl-{\beta}-_{D}-glucopyranoside$)(12). The structures were established by spectroscopic and chemical methods.

• Journal of Magnetics
• /
• 제15권1호
• /
• pp.21-24
• /
• 2010

A new synthetic method for the formation of uniform $\alpha-Fe_2O_3$ nanoparticles was reported and their magnetic properties were investigated. The sonochemical synthesis and the subsequent take-off technique resulted in spherical shaped $\alpha-Fe_2O_3$ nanoparticles with an average diameter of 60 nm. The temperature- and applied magnetic field-dependent magnetization of the $\alpha-Fe_2O_3$ nanoparticles was explained by the sum of two contributions, i.e., the Morin transition and superparamagnetism, because the critical size for superparamagnetism was within the size variation of the nanoparticles.

• Archives of Pharmacal Research
• /
• 제21권1호
• /
• pp.67-69
• /
• 1998

Three TNF-$\alpha$inhibitory lignans were isolated from the flower buds of Magnolia fargesii through bioassay-guided isolation. They were identified as eudesmin, magnolin and lirioresinol-B dimethylether on the basis of their spectroscopic data. All three lignans showed inhibitory effects on TNF-$\alpha$ production in LPS-stimulated murine macrophage cell line, RAW264.7 and eudesmin showed the strongest activity ($IC_{50}=51{\mu}M)$.

• 충청수학회지
• /
• 제20권1호
• /
• pp.11-21
• /
• 2007

Given a nonlinear function f : $\mathbb{R}{\rightarrow}\mathbb{R}$ that has a simple real zero ${\alpha}$, a new numerical method to be called k-fold pseudo- Halley's method is proposed and it's error analysis is under investigation to confirm the convergence behavior near ${\alpha}$. Under the assumption that f is sufficiently smooth in a small neighborhood of ${\alpha}$, the order of convergence is found to be at least k+3. In addition, the corresponding asymptotic error constant is explicitly expressed in terms of k, ${\alpha}$ and f as well as the derivatives of f. A zero-finding algorithm is written and has been successfully implemented for numerous examples with Mathematica.

• 산업기술연구
• /
• 제21권B호
• /
• pp.331-339
• /
• 2001

Zero to tension fatigue tests and strain controlled fatigue tests were carried out to find how initial strain induced martensite, ${\alpha}^{\prime}$ affects low and high cycle fatigue behavior and fatigue crack growth mechanisms. Microscopic study and phase analysis were carried out with TEM, SEM, EDAX, Optical Microscope, Ferriscope, and X-ray diffractometry. The amount of Initial ${\alpha}^{\prime}$ was controlled from 0% to 33% by controlling the temperatures for cold working and heat treatment. Lower contents of initial ${\alpha}^{\prime}$ showed higher fatigue resistance in low cycle fatigue but lower fatigue resistance in high cycle fatigue because it is ascribed to the more transformation of ${\alpha}^{\prime}$ martensite during low cycle fatigue and higher ductility. In high cycle fatigue, fatigue life is attributed to the strength and phase transformation of austenite into ${\alpha}^{\prime}$ during fatigue was negligible. ${\gamma}$ boundary, ${\gamma}/twin$ boundary, and ${\gamma}/{\alpha}^{\prime}$ boundary were found to be the preferred site of fatigue crack initiation.

• 대한한방부인과학회지
• /
• 제21권2호
• /
• pp.152-165
• /
• 2008

Purpose: It is the purpose of this study to investigate the anti-inflammatory effects and mechanism of cheukbaekjurpihwan(CBJPH) extract on LPS (lipopolysaccharide)-induced inflammatory mediators in murine peritoneal macrophages. Methods: To evaluate anti-inflammatory effects of CBJPH extract, the production of cytokines(TNF-${\alpha}$(tumor necrosis factor-alpha), IL(interleukin)-6, IL-12) and NO(nitric oxide) was measured in vitro and in vivo. And western blot analysis has been done to look into the mechanism. Results: CBJPH extract reduced LPS-induced NO, TNF-${\alpha}$ and IL-6, IL-12 productions in peritoneal macrophages. CBJPH extract inhibited the activation of JNK(c-Jun N-terminal kinase), but didn't inhibit the activation of MAPKs (mitogen-activated protein kinases) such as p38, ERK1/2(extracelluar signal-regulated kinase1/2) and the degradation of $I_{\kappa}B-{\alpha}$(inhibitory kappa B-alpha) in the LPS-stimulated peritoneal macrophages. CBJPH extract suppressed LPS-induced endotoxin shock and the productions of TNF-${\alpha}$, but not of IL-6, after an oral administration of CBJPH extract Conclusion: CBJPH extract suppressed the productions of LPS-induced NO and cytokines by preventing JNK from phosphorylation, which may provide a clinical basis for anti-inflammatory properties of CBJPH.

• Molecules and Cells
• /
• 제21권3호
• /
• pp.356-359
• /
• 2006

The transcription factor E2F1 coordinates cell cycle progression and induces apoptosis in response to DNA damage stress. Aside from DNA damage, the role of E2F1 in the endoplasmic reticulum (ER) stress signaling pathways is unclear. We found that $E2F1^{-/-}$ murine embryonic fibroblasts (MEFs) are resistant to apoptosis triggered by the ER stress inducer thapsigargin. In addition, E2F1 deficiency results in enhanced phosphorylation of eukaryotic translation initiation factor $2{\alpha}$ ($elF2{\alpha}$). These results therefore indicate that E2F1 deficiency increases phosphorylation of $elF2{\alpha}$ in response to ER stress triggered by thapsigargin, and suggest that the reduction in ER stress-induced apoptosis in E2F1-deficient cells is related to the high level of $elF2{\alpha}$ phosphorylation.

• Journal of Microbiology and Biotechnology
• /
• 제20권12호
• /
• pp.1711-1716
• /
• 2010

A gene encoding the ${\beta}$-xylosidase/${\alpha}$-arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium ${\beta}$-xylosidase/${\alpha}$-N-arabinosidase and Bacillus cellulosilyticus ${\alpha}$-arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a C-terminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on para-nitrophenyl-${\alpha}$-arabinofuranoside (pNPA) as well as para-nitrophenyl-${\beta}$-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

• 대한화학회지
• /
• 제27권4호
• /
• pp.279-286
• /
• 1983

몇가지의 알파입자를 방출하는 핵종, 즉 악티늄족 원소들, $^{207}Bi$ and $^{210}Po$을 전해석출하는 장치를 만들었다. 스텐레스 원판으로된 환원전극에 이 동위원소들을 석출했으며(석출부분 직경=18mm), 산화전극으로는 백금선을 썼다. 전해질로 염화암모늄을 쓰고, 초기 pH=4, 염소이온농도=0.6M이하, 용액부피=15ml로 하여 1.5암페어(전류밀도=0.59A/$cm^2$)의 전류를 100분간 흘려주어 98.3%의 석출 회수율과 ${\pm}$0.7%의 재현도를 얻었다. 석출된 시료의 알파스펙트럼을 측정한 결과 에너지 분리도로서 $^{210}Po=18.3keV, ^{234}U=21.8keV$ 및 $^{239}Pu=36.0keV$인 반치전폭(full width at half maximum)을 얻었다. 국산 천연우라늄(충북·괴산) 시료를 전해석출하여 그의 알파스펙트럼을 구한 결과 $^{238}U\;:\;^{234}U\;=\;:\;6.1{\times}10^{-5}$을 얻었으며 $1.8{\sim}10^{13} neutrons/cm^2{\cdot}sec$인 중성자속으로 144일 동안 쪼여준 238U 시료를 전해석출하여 그의 알파스펙트럼을 구한 결과 $^{238}U\;:\;^{239}Pu\;:\;241Am\;=\;100\;:\;0.0263\;:\;5.20{\times}10^{-5}$을 얻었다. 조사시료중의 $^{238}U$에 대한 본실험의 정량결과는 고체형광측정법 및 질량 스펙트럼법에 의한 결과들과 상대오차 1.6% 이내에서 일치하였으며, $^{239}Pu$의 경우는 음이온교환분리-알파스펙트럼 측정 및 삼불화테노일아세톤(thenoyltrifluoroacetone)을 쓴 용매추출-알파스펙트럼 측정에 의한 정량결과들과 상대오차 ${\pm}$4.0%이내에서 일치하였다.