• Archives of Pharmacal Research
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• 제21권5호
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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.

• 열처리공학회지
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• 제32권4호
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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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• 제8권5호
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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.

• 대한화학회지
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• 제23권2호
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• pp.99-103
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• 1979

세개의 ${\alpha}$,${\beta}$-불포화알데히드, 신남알데히드, 크로톤알데히드, 아크로레인을 여러가지 일차 아민 존재하에서 테트라카르보닐철산염으로 환원시켜 상당히 다른 수득률로 N-알킬아민을 합성하였다. 보통, $KHFe(CO)_4$ (22mmole)와 일차아민(22∼44mmole)과 ${\alpha}$,${\beta}$-불포화 알데히드 (22mmole)를 에탄올 용매에 넣고 일산화탄소 분위기하에 실온에서 9∼60시간 자석 젓개로 저어주면 일산화탄소를 천천히 흡수하면서 반응이 진행된다. 생성물은 가스크로마토그래피, 질량분석스펙트럼, 핵자기공명스펙트럼, 적외선스펙트럼 등으로 그 구조를 알았다.

• 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.

• Natural Product Sciences
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• 제16권1호
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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.

• 한국식품과학회지
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• 제42권1호
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• pp.109-114
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• 2010

결명자(Cassia obtusifolia) 및 포공영(Taraxacum platycarpum), 유근피(Ulmus macrocarpa)로 제조된 생약재 추출혼합물이 in vitro와 in vivo상에서 아토피 피부염에 미치는 영향을 실험하였다. HMC-1 cell을 이용하여 비만세포의 $\beta$-hexosaminidase 방출량을 측정한 결과, 단일 추출물보다 추출복합물이 탈과립을 억제하는 효과가 우수한 것으로 측정되었다. 그리고 HMC-1 cell에서 PMA와 A23187로 자극하였을 때 생성되는 염증성 cytokine의 분비에서도 추출혼합물의 저해 효과가 가장 높게 나타났다. 아토피 질환모델인 NC/Nga 마우스를 사용하여 생약재 추출혼합물의 아토피 저감효과를 측정한 결과, 진드기 추출물에 의해 발진된 마우스의 귀두께 및 조직학적인 부종 관찰을 통해 생약재 추출혼합물 농도가 증가함에 따라 대조군에 비해 귀 두께 및 부종의 감소가 관찰되었다. 또한 마우스의 혈중 IgE 농도와 이와 관련된 cytokine의 농도를 측정한 결과, 생약재 추출혼합물 투여농도가 증가함에 따라 IgE의 농도가 유의적으로 감소하였고, IgE의 과발현을 유도하는 IL-4의 분비 억제 및 IFN-$\gamma$의 분비가 증가되는 것으로 나타나 생약재 혼합추출물의 섭취가 아토피 피부염 증세 완화 효과에 도움이 되리라 사료된다.

• 생약학회지
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• 제31권1호
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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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• 제30권2호
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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.

• 산업식품공학
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• 제14권3호
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• pp.243-248
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• 2010

${\beta}$-Glucosidase 효소활성이 높은 균주를 선발하기 위하여 다양한 김치에서 분리된 젖산균의 ${\beta}$-glucosidase 활성을 탐색하였다. 김치에서 분리된 156개의 젖산균 중 134개의 균주만이 cellobiose를 탄소원으로 대사하였으며, 세포내 ${\beta}$-glucosidase 활성이 세포외 활성보다 현저히 높았다. 배추김치에서 분리된 W. cibaria KFRI88010 균주가 3.7${\pm}$0.5 unit/mg protein으로서 가장 높은 세포내 ${\beta}$-glucosidase 효소활성을 나타내었으며, 효소활성은 pH 5, ${37^{\circ}C}$ 반응조건에서 가장 높게 나타났다. $Mn^{2+}$를 비롯한 금속이온은 효소활성을 크게 저해하였다. W. cibaria KFRI88010 균주를 배양할 때 사용한 탄소원 중, fructose는 cellobiose나 glucose와 비교하여 약 2.5배 이상의 높은 세포내 ${\beta}$-glucosidase 효소활성을 나타내었다.