• Archives of Pharmacal Research
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• v.21 no.5
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• pp.503-507
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• 1998

Percutaneous absorption and model membrane variations of melationin (MT) in aqueous-based propylene glycol and $2-hydroxypropyl-{\beta}-cyclodextrin $vehicles were investigatted. the excised hairless mouse skin (HMS) and two synthetic ethylene vinyl acetate (EVA) and microporous polyethylene (MPE) were selected as a model membrane. the solubility of MT was determined by phase equilibrium study. the vertical $Franz{\circledR}$ type cell was used for diffusion study. The concentration of MT was determined using reverse phse HPLC system. The MT solubility was the highest in a mixture of PG and $2-HP{\beta}CD$. The percutaneous absorption of MT through excised HMS increased as the solubility increased. However, the permeability coefficient decreased and then slightly increased in mixture of PG and $2-HP{\beta}CD$. On the other hand, both flux and permeability coefficient through EVA membrane decreased as the solubility increased. No MT was detected over 12 h after starting diffusion through MPE membrane. The flux of MT was dependent on the type of membrane selected. Flux of MT was greatest in excised HMS followed by EBA and MPE membrane. Flux of MT through EVA membrane was 5-20 times lower when compared to excised HMS. Interestingly, volumes of donor phase when MPE membrane was used, significantly increased during the study period. the HMS might be applicable to expect plasma concentration of MT in human subjects based on flux and pharmacokinetic parameters as studied previously. the current studies may be applied to deliver MT transdermally using aqueous-based vehicles and to fabricate MT dosage forms.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.4
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• pp.168-174
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• 2019

The microstructural features and relative room temperature mechanical properties were investigated in various compositions of Mg-xAl-yZn alloys by thxiomolding process. The microstructure was composed of ${\alpha}$-Mg particles and mixture of ${\alpha}$-Mg and ${\beta}-Mg_{17}Al_{12}$ eutectic phase. The amount of ${\beta}-Mg_{17}Al_{12}$ eutectic phase in mixture was increased with increasing Al and Zn contents without grain refinement. After adding Ti content, however, the morphology of ${\beta}-Mg_{17}Al_{12}$ eutectic phase transformed from net-like to discontinuous shape and the average grain size reduced. To determine the relationship between microstructural features and their mechanical properties, a tensile test was performed at room temperature. As a result, it was found that the mechanical properties were improved in all of Ti contained alloys due to increased elongation and the mechanisms are discussed in terms of microstructural evolution.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.441-448
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• 1998

A cellobiose-utilizing recombinant yeast having $\beta$-glucosidase activity was developed for ethanol production from a mixture of glucose and cellobiose. Using $\delta$-sequences of Tyl transposon of yeast as target sites for homologous recombination, a heterologous gene of $\beta$-glucosidase was integrated into the chromosome of Saccharomyces cerevisiae. The $\delta$-integrated recombinant yeast, Saccharomyces cerevisiae L2612 (Pb-BGL), showed perfect mitotic stability even in nonselective media and showed ca. 1.5 fold higher $\beta$-glucosidase activity than the recombinant yeast harboring the $2\mu$-based plasmid vector system. A mathematical model was developed to describe the $\beta$-glucosidase formation and ethanol production from the Saccharomyces cerevisiae L2612 ($p\delta-BGL$). The model newly described that the heterologous $\beta$-glucosidase production mediated by ADH1 promoter is regulated by glucose and repressed by ethanol.

• Journal of the Korean Chemical Society
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• v.23 no.2
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• pp.99-103
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• 1979

The reductive amination of three ${\alpha}$,${\beta}$-unsaturated aldehydes, cinnamaldehyde, crotonaldehyde, and acrolein are carried out successfully by tetracarbonylhydridoferrate in the presence of various primary amines. In a typical reaction, a mixture of potassium tetracarbonylhydridoferrate (22 mmole), an amine (22∼44 mole) and ${\alpha}$,${\beta}$-unsaturated aldehyde (22 mmole), in ethanol (30∼50 ml) was stirred for 9∼60 hours at room temperature under carbon monoxide atmosphere. All the products were characterized as secondary amines by mass, infrared, and nmr spectra as well as gas chromatographic data.

• Korean Journal of Materials Research
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• v.12 no.5
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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.

• Natural Product Sciences
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• v.16 no.1
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• pp.20-25
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• 2010

Fourteen compounds were isolated from the n-BuOH fraction of the roots of Aralia cordata (syn. = A. continentalis). Through spectroscopic method, the chemical structures were elucidated as: caffeic acid (1), protocatechuic acid (2), thymidine (3), uridine (4), methyl-$\alpha$-D-fructofuranoside (5), a mixture (3 : 1) of $\beta$-D-fructopyranoside and $\beta$-D-fructofuranoside (6), 1-methyl 1,2,3,4-tetrahydro-$\beta$-carboline-3-carboxylic acid (7), methyl-$\beta$-D-fructofuranoside (8), sucrose (9), 5-caffeoylquinic acid (chlorogenic acid) (10), 3-caffeoylquinic acid (neochlorogenic acid) (11), 4-caffeoylquinic acid (cryptochlorogenic acid) (12), 3,5-di-O-caffeoylquinic acid (13), and 1-kestose [$\beta$-D-fructofuranosyl-($2{\rightarrow}1$)-$\beta$-D-fructofuranosyl-($2{\rightarrow}1$)-$\alpha$-D-glucopyranoside] (14). Among them, compounds 5, 7, 8, and 10 - 14 were isolated from this plant for the first time.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.109-114
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• 2010

The in vivo and in vitro effects of oriental herb extracts of Cassia obtusifolia, Taraxacum platycarpum and Ulmusmacrocarpa on anti-atopic allergic reaction were evaluated in this study. A mixture of these extracts exhibited more potent anti-allergic activities in human mast cells than those from individual extracts. The herbal mixture significantly inhibited the release of compound 48/80-induced $\beta$-hexosaminidase release in the human mast cell line, HMC-1. The mixture also suppressed the production of PMA and A23187-induced inflammatory cytokines in HMC-1 cells. To further investigate the in vivo effects of the herbal mixture, a Dermatophagoides farinae (DF)-induced atopic dermatitis mouse model was utilized. Oral administration of the herbal mixture significantly decreased the ear thickness and swelling in DF treated NC/Nga mice in a dose dependent manner. Furthermore, serum levels of IgE and interleukin-4 (IL-4) were significantly decreased, whereas interferon-gamma (IFN-$\gamma$) levels were increased in the mixture administrated groups when compared to the control. Taken together, our data indicate the possibility of using a mixture of the oriental herb extract to relieve symptoms of atopic dermatitis.

• Korean Journal of Pharmacognosy
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• v.31 no.1
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• pp.39-44
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• 2000

A sterol mixture, 3-O-glucosides of these sterols, 6'-O-fattyacyl ester of these sterol glucosides, kaempferol, quercetin and isoquercitrin were isolated from the whole plants of Hypericum ascyron L. The sterols were found to be a mixture of ${\beta}-sitosterol$, campesterol and stigmasterol by GC-MS. The kinds of fatty acids linked at 6'-OH of sterol glucoside ester mixture were shown to be palmitic acid, stearic acid, oleic acid and linoleic acid by GC-MS. Three flavonoids were identified by spectroscopic methods and comparisons of mixed mp and co-TLC with authentic specimens.

• KSBB Journal
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• v.30 no.2
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• pp.53-57
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• 2015

In this study, the production of total reducing sugar from macro green-algae Enteromorpha intestinalis by enzymatic hydrolysis was investigated. As a result of enzymatic hydrolysis using 13 kind commercial enzymes, the highest yield of 8.75% was obtained from Viscozyme L, which is multi-enzyme complex such as cellulase, arabanase, beta-glucanase, hemicellulase and xylanase. As a control, only 0.33% and 0.27% yield were obtained from 1% sulfuric acid and 0.05 M citrate buffer (pH 4.8), respectively. In the case of enzyme mixture, the mixture of $Viscozyme^{(R)}$ L and $Cellic^{(R)}$ CTec2 (1:1) was presented the highest yield of 10.67%. Finally, the 14.99% yield was obtained at 36 hr under the condition of 10% biomass and 30% enzyme mixture.

• Food Engineering Progress
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• v.14 no.3
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• pp.243-248
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• 2010

The ${\beta}$-glucosidase (E.C. 3.2.1.21) production capabilities of lactic acid bacteria isolated from a variety of kimchi (fermented vegetables) were examined. When grown in a medium containing cellobiose as carbon source, most lactic acid bacteria showed significantly higher intracellular levels of ${\beta}$-glucosidase than the extracellular levels. A maximum intracellular ${\beta}$-glucosidase activity of 3.7${\pm}$0.5 (unit/mg protein) was obtained in the case of Weissella cibaria KFRI88010 isolated from kimchi. The optimum reaction conditions for W. cibaria KFRI88010 ${\beta}$-glucosidase activity were pH 5.0 and ${37^{\circ}C}$, and addition of divalent cations to the reaction mixture resulted in a notable decrease in enzyme activity. The ${\beta}$-glucosidase activity was enhanced twofold when W. cibaria KFRI88010 was grown in a medium containing fructose as compared with to a medium containing glucose or cellobiose.