• 한국생명과학회:학술대회논문집
• /
• 한국생명과학회 2002년도 제35회 학술심포지움 및 춘계학술대회
• /
• pp.73-73
• /
• 2002

• 대한수학회보
• /
• 제49권1호
• /
• pp.99-107
• /
• 2012

The concept of Hilbert space dissipative norm was introduced in [8] to obtain necessary and sufficient conditions for exponential stability of contraction semigroups. In the present paper we show that the same concept can also be used to derive further properties of contraction semigroups, as well as to characterize strongly stable semigroups that are not exponentially stable.

• 대한수학회보
• /
• 제56권3호
• /
• pp.585-596
• /
• 2019

It is shown that a pair of Hilbert space operators V and W such that $V^*W=I$ (called a biisometric pair) shares some common properties with unilateral shifts when orthonormal bases are replaced with biorthogonal sequences, and it is also shown how such a pair of biisometric operators yields a pair of biorthogonal sequences which are shifted by them. These are applied to a class of Laguerre operators on $L^2[0,{\infty})$.

• 한국미생물·생명공학회지
• /
• 제16권4호
• /
• pp.259-264
• /
• 1988

Pseudomonas sp.로 동정된 토양분리균의 inulinase를 ammonium sulfate 분획, DEAE Sephadex A-50 Chromatography, Sephadex G 100 및 Sephadex G200 gel여과 등의 과정을 거쳐 정제 한 결과 inulinase PI과 PII의 두 isoenzyme으로 분리되었으며 각각 약 24배와 17배 정제되어 단일단백질로 분리되었다. PI, PII 두 isoenzyme은 다같이 sucrose, raffinose 및 levan은 분해하지 못하고 inulin만을 endo-type로 분해 절단하는 $\beta$-2,1-fructanfructano hydrolase(EC 3.2.1.7)임이 밝혀졌다. 효소활성 최적온도는 두 효소가 같은데 비해 (55$^{\circ}C$), 최적 pH는 PI이 pH5.5, PII가 pH6.0으로 약간의 차이를 보였다. Inulin에 대한 Km값은 PI ; 2$\times$$10^{-3}$M, PII : 5$\times$$10^{-3}$M로써 PI효소가 PII보다 약간 높은 친화력을 보였다.

• 대한지역사회영양학회:학술대회논문집
• /
• 대한지역사회영양학회 2004년도 춘계학술대회
• /
• pp.436-437
• /
• 2004

폐경기성 골다공증의 치료 방법인 에스트로겐 투여에 의한 위험성을 보완하기 위해 한약재 및 식품 등 천연물의 활성성분을 이용한 대체 요법에 대한 연구가 진행되면서, 이소플라본(isoflavone)계 식물성 에스트로겐을 함유한 기능성식품의 개발이 진행되고 있다. 특히 콩과식물 중 isoflavone 함량뿐 아니라 배당체와 결합되지 않은 aglycone 함량이 높은 서목태(쥐눈이콩; 약콩)와 무기질 홉수 중진 효과를 지닌 프럭토즈폴리머(levan; beta-2,6 linked fructose polymer, ∼6,000,000 Da)를 폐경 후 여성들에게 공급하여 골형성 지표와 골흡수 지표의 변화, 혈중 칼슘 농도, 골대사를 살펴보고 골밀도의 변화를 살펴봄으로써 골다공증 예방제로서의 기능성물질의 효능을 살펴보고 신물질의 개발에 기여하고자 하였다.(중략)

• 한국영양학회:학술대회논문집
• /
• 한국영양학회 2002년도 춘계학술대회
• /
• pp.102-102
• /
• 2002

• 대한수학회지
• /
• 제40권6호
• /
• pp.933-942
• /
• 2003

It is shown that if a paranormal contraction T has no nontrivial invariant subspace, then it is a proper contraction. Moreover, the nonnegative operator Q = T/sup 2*/T/sup 2/ - 2T/sup */T ＋ I also is a proper contraction. If a quasihyponormal contraction has no nontrivial invariant subspace then, in addition, its defect operator D is a proper contraction and its itself-commutator is a trace-class strict contraction. Furthermore, if one of Q or D is compact, then so is the other, and Q and D are strict ontraction.

• Journal of Microbiology
• /
• 제34권4호
• /
• pp.305-310
• /
• 1996

A microorganism producing carboxymethyl-cellulase (CMCase) was isolated from 300 soil and compost samples. The isolate was identified as Bacillus sp. by $Biolog^{TM}$ test and fatty acid analysis, and named as Bacillus sp. KD1014. The isolate could degrade, in addition to CMC, various kinds of polysaccharides such as levan, xylan, starch, and filter paper but hardly degrade microcrystalline Avicel. The optimum growth and CMCase production of the isolate was observed between 16-and 25 hr-culture at 45$^{\circ}C$ and pH 5.0. The maximum CMCase activity was observed at pH 4.5 and 6$0^{\circ}C$. The CMCase was found to bind to Avicel. The CMCase was internally cleaved as growth continued. When crude supernatant was used for activity staining, three major bands were detected on a native gel, however, only one major band was detected on a denaturating gel after removal of the detergent.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2002년도 생물공학의 동향 (X)
• /
• pp.188-191
• /
• 2002

A glucan and a fructan producing enzymes from Leuconostoc mesenteroides NRRL B-1149 were prepared and concentrated from the cu1ture of 1.5% sucrose using polysulfone ultrafiltration hollow fiber in the presence of 0.1% (w/v) Tween 80, 1 mM $CaCl_2$, and 0.02% $NaN_3$. The molecular masses of the enzymes were estimated to be about 213.6 kDa and 180 kDa, respectively, based on the PAS staining for the glucosyltransferase and Mukasa method for fructosyltransferase. Polymers produced by the enzymes showed different solubility; an insoluble glucan and a soluble fructan. The linkages of polymers were determined by methylation using Hakomori reagent and following acid hydrolysis. The glucan was composed of ${\alpha}$-1,6 and 1,3 linkages and the fructan showed similar linkage data of levan.

• 대한치과의사협회지
• /
• 제9권12호
• /
• pp.812-818
• /
• 1971

The present investigation describes the chemical nature of purified extracellular polysaccharides synthesized by tow resembling streptococci, Streptococcus salivarius strain SD-1 and Streptococcus mitis strain SD-9, which was isolated from human dental plaque, with the following results. 1. Extracellular polysaccharide by Streptoccus salivarius strain SD-1 is recovered mostly in Fraction I-and II-45% of the presne purification procedure, leaving trace amount in Fraction I-and II-70%. 2. The dextran is the major polysaccharides in Fraction I-and II-45% of both strains with minor amounts of levan. 3. The Fraction I-and II-45% of both strains contain glucose and fructose, which its 70% of the same fractions glucose only. 4. It appears that the glycerol was the major end product of the Smith degradation of the Fraction I-45% of both strains.