• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.656-659
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• 2001

Cyclodextrin glucanotransferase (CGTase) (EC 2.4.1.19) use starch to produce cyclic maltooligosaccharides (cyclodextrins, CDs) which are of interest in various applications. To obtain a novel CGTase having high CD-forming activity, ${\beta}-cyclodextrin$ glucanotransferase $({\beta}-CGTase)$ from Bacillus firmus var. alkalophilus was modified through site-directed mutagenesis and constructed five mutants, H59T, H59Q, Y96M, 9O-PPI-93, and ${\Delta}(148-154)D$, respectively. Y96M and ${\Delta}(148-154)D$ showed much higher level of conversion yields of starch into CDs from 28.6% to about 39% compared to wild-type ${\beta}-CGTase$, respectively, but 90-PPI-93 maintained similar convesion yields of starch to CDs. And their ${\beta}-CD$ ratios to total CDs were not changed and maintained, and convesion yields to linear maltooligosaccharides of all mutants were not changed significantly. These results indicates that five mutations of ${\beta}-CGTase$ from Bacillus firmus var. alkalophilus appears to be important roles for increase of overall CD production rather than change of its product specificity, especially.

• IMMUNE NETWORK
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• 제14권5호
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• pp.237-240
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• 2014

Endoglin (also known as CD105 or TGF-${\beta}$ type III receptor) is a co-receptor involved in TGF-${\beta}$ signaling. In atherosclerosis, TGF-${\beta}$ signaling is crucial in regulating disease progression owing to its anti-inflammatory effects as well as its inhibitory effects on smooth muscle cell proliferation and migration. Endoglin is a regulator of TGF-${\beta}$ signaling, but its role in atherosclerosis has yet to be defined. This review focuses on the roles of the various forms of endoglin in atherosclerosis. The expression of the two isoforms of endoglin (long-form and short-form) is increased in atherosclerotic lesions, and the expression of the soluble forms of endoglin is upregulated in sera of patients with hypercholesterolemia and atherosclerosis. Interestingly, long-form endoglin shows an atheroprotective effect via the induction of eNOS expression, while short-form and soluble endoglin enhance atherogenesis by inhibiting eNOS expression and TGF-${\beta}$ signaling. This review summarizes evidence suggesting that the different forms of endoglin have distinct roles in atherosclerosis.

• Archives of Pharmacal Research
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• 제25권3호
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• pp.289-292
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• 2002

The ethyl acetate extract of the leaves of Ixeris sonchifolia afforded two new and two known sesquiterpene lactone glucosides of the guaiane-type, together with a known alkenol glucoside. The known compounds were identified as ixerin Z (1), ixerin Z-6'-p-hydroxyphenylace-tate (2), and (Z)-3-hexen-1-ol-$\beta$-D-glucopyranoside (3), respectively. The structures of the new compounds were elucidated as 11, 13a-dihydroixerin Z [4, 3-hydroxy-2-oxo-guaia-1 (10), $3-dien-5{\alpha},6{\beta},7{\alpha},11{\beta}H-12,6-olide-3-O-{\beta}-D-glucopyranoside],{\;}and{\;}3,10{\$beta}-dihydroxy-2-oxo-guaia-3,11(13)-dien-1{\alpha},5{\alpha},6{\alpha},7aH-12,6-olide-10-O-{\beta}-D-glucopyranoside$ (5), respectively. The cytotoxicity of these compounds against human hepatocellular carcinoma cell (HepG2) and human melanoma cell (SK-MEL-2) was evaluated.

• Plant Resources
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• 제1권1호
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• pp.33-37
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• 1998

Carotenoid compounds in embryos of wild-type(WT) and viviparous mutants of maize(Zea mays L.) were analyzed using high performance liquid ehromatography (HPLC) with a photodiode array detector. Zeaxanthin accumulates in WT embryos as the major carotenoid. Phytoene accumulates in vp2 and vp5. Phytofluene in w3 and ${\xi}$-carotene in the vp9 mutant embryos. This indicates that the vp2 and vp5 mutants impair phytoene desaturase from 15-cis-phytoene to 15-cis-phytofluene. The w3 mutant has neither an isomerase from 15-cis-phytofluene to all-trans-phytofuene nor phytofluene desaturase from phytofluene to ${\xi}$-carotene. The vp9 mutant does not have the ${\xi}$-carotene desaturase from ${\xi}$-carotene to lycopene. Our analysis shows that the terminal carotenoid. ${\gamma}$-carotene(${\beta},{\Psi}$-carotene), accumulates in the vp7 mutant embryos. The ${\varepsilon}$-carotene(${\varepsilon},{\varepsilon}$-carotene), a product of ${\delta}$-carotene(${\varepsilon},{\Psi}$-carotene) in some plants, however, has not been found in maize embryos. The vp7 mutant impairs a cyclization step from ${\gamma}$-carotene to both ${\beta}$-carotene and ${\alpha}$-carotene. We suggest that monocyclic ${\gamma}$-carotene is the sole precursor of both bicyclic ${\beta}$-carotene(${\beta},{\beta}$-carotene) and ${\alpha}$-carotene(${\beta},{\varepsilon}$-carotene) in maize.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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• pp.115-126
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• 1998

Four new dammarnae-glycosides named ginsenosides Rgs, Rh4, RsB and Rf2 have been isolated 1'rom Korean red ginseng, the root of Panax ginseng C. A. Meyer (Araliaceae) and their chemical structures have been elucidated by chemical and spectroscopic methods, including'H-'H COSY, HMQC, HMBC, NOESY, as 3-0- [$\beta$-D-glucopyranosyl(1 ~2)-$\beta$-D-glucopyranosyl] dammar-20(22) , B4-diene-3P,12P-diol (ginsenoside Rgs),6-0-$\beta$-D-glucopyranosyl-dammar-20(22),24-diene-3P,6P, 12P-triol (ginsenoside Rh4),3-0- [6" -0-acetyl-D-glucopyranosyl(1 ~2)--D-glucopyranosyl] 20(5)- protopanaxadiol (ginsenoside Rs3) and 6-0- [u-L-rhamno-pyranosyl(1 ~2)-$\beta$-D-glucopyranosyl] dammarane -3$\beta$, 6a, 12 $\beta$, 20(R),25-pentol(ginsenoslde Rfa). The absolute stereo structure of a double bond at C-20(22) was determined as entgegen type by applying NOESY.OESY.

• 한국세라믹학회지
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• 제26권2호
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• pp.195-200
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• 1989

The Silica-Carbon mixture was made with addition of carbon black in the composition which monodispersed spherical fine silica was formed by the hydrolysis of ethylsilicate, mole ratio of Carbon/Alkoxide was 3.1 and $\beta$-SiC powder was synthesized by reacting this mixture at 1,350~1,50$0^{\circ}C$ in Ar atmosphere. The results of this study are as follow : (1) The purity of synthesized $\beta$-SiC powder was above 99.98% and it was in cubic modification with lattice constant of 4.3476$\AA$. (2) The rate-controlling steps varied with the reaction temperature for the syntehsis of $\beta$-SiC in this study ; nucleation and growth of $\beta$-SiC at 1,350~1,40$0^{\circ}C$, interfacial reaction at 1,45$0^{\circ}C$ and diffusion described by Jander Equation at 1,50$0^{\circ}C$. (3) When the rate-determining step was nucleation and growth, the activation energy was about 87.8kcal/mol.

• 한국재료학회지
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• 제12권5호
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• pp.375-381
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• 2002

N-type ${\beta}-FeSi_2$ with a nominal composition of $Fe_{0.98}Co_{0.02}Si_2$ powders has been produced by mechanical alloying process and consolidated by vacuum hot pressing. As-milled powders were of metastable state and fully transformed to ${\beta}-FeSi_2$ phase by subsequent isothermal annealing. However, as-consolidated $Fe_{0.98}Co_{0.02}Si_2$ consisted of untransformed mixture of ${\alpha}-Fe_2Si_ 5$ and $\varepsilon$-FeSi phases. Isothermal annealing has been carried out to induce the transformation to a thermoelectric semiconducting ${\beta}-FeSi_2$ phase. The transformation behavior of ${\beta}-FeSi_2$ was investigated by utilizing DTA, a modified TGA under magnetic field, SEM, and XRD analyses. Isothermal annealing at $830^{\circ}C$ in vacuum led to the thermoelectric semiconducting ${\beta}-FeSi_2$ phase transformation, but some residual metallic $\alpha$ and $\varepsilon$ phases were unavoidable even after prolonged annealing. Thermoelectric properties were remarkably improved by isothermal annealing due to the transformation from metallic $\alpha$ and $\varepsilon$ phases to semiconducting phases.

• Journal of Microbiology and Biotechnology
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• 제7권5호
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• pp.360-362
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• 1997

A transposon Tn5 mutant of Rhodobacter sphaeroides 2.4.1 was isolated for its impaired ability of growth on minimal medium containing ${\beta}$-hydroxybutyric acid as a sole carbon source. The mutant, R. sphaeroides S7 showed approximately 6-fold decrease in ${\beta}$-hydroxybutyrate dehydrogenase activity compared with that of wild type. In R. sphaeroides S7 the Tn5 was located in DNA region corresponding to a 4.2-kb EcoRI DNA fragment of R. sphaeroides 2.4.1 chromosome.

• Toxicological Research
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• 제17권2호
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• pp.139-142
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• 2001

Sexual behavior and reproductivity of male fIsh were studied as an in vivo screening method of endocrine disruptors. Male medaka (Oryzias latipes) were exposed to 17$\beta$-estradiol at nominal concentrations of 2 and 20 $\mu\textrm{g}$/l for 14 days. After exposure of the chemical, sexual behavior between male medaka and normal female which were injected with prostaglandin $F_{2\alpha}$ just before the test, was analysed by using video camera for one hour. Normal control male showed courtship dancing such as following, guarding, dancing and crossing while 17$\beta$-estradiol treated male did not show any type oj courtship dancing. Furthermore, fecundity and fertility were significantly decreased in the treated group. It was suggested that analysis of sexual behavior could be a useful endpoint for the screening of the endocrine disruptors.

• 대한수학회논문집
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• 제10권4호
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• pp.881-887
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• 1995

Let f be a measurable function on the unit ball B in $C^n$, then we define a maximal function $M_p(f), 1 \leq p < \infty$, by $$ M_p(f)(\zeta ) = \sup_{\delta > 0}(\frac{1}{\sigma(\beta(\zeta, \delta))} \int_{T(\beta(\zeta, \delta))} $\mid$f(z)$\mid$^p \frac{d\nu(z)}{(1-$\mid$z$\mid$^n})^{1/p} $$ where $\sigma$ denotes the surface area measure on S, the boundary of B, and $T(\beta(\zeta, \delta))$ denotes the tent over the ball $\beta(\zeta, \delta)$. We prove that the maximal operator $M_p$ belongs to the Muckenhoupt class $A_1$.