• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.959-966
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• 2016

Chlorophyll synthase (ChlG) and bacteriochlorophyll synthase (BchG) have a high degree of substrate specificity. The BchG mutant of Rhodobacter sphaeroides, BG1 strain, is photosynthetically incompetent. When BG1 harboring chlG of Synechocystis sp. PCC 6803 was cultured photoheterotrophically, colonies arose at a frequency of approximately 10^-8. All the suppressor mutants were determined to have the same mutational change, ChlG_I44F. The mutated enzyme ChlG_I44F showed BchG activity. Remarkably, BchG_F28I, which has the substitution of F at the corresponding 28^th residue to I, showed ChlG activity. The K_m values of ChlG_I44F and BchG_F28I for their original substrates, chlorophyllide (Chlide) a and bacteriochlorophyllide (Bchlide) a, respectively, were not affected by the mutations, but the K_m values of ChlG_I44F and BchG_F28I for the new substrates Bchlide a and Chlide a, respectively, were more than 10-fold larger than those for their original substrates, suggesting the lower affinities for new substrates. Taken together, I44 and F28 are important for the substrate specificities of ChlG and BchG, respectively. The BchG activity of ChlG_I44F and the ChlG activity of BchG_F28I further suggest that ChlG and BchG are evolutionarily related enzymes.

• 호남수학학술지
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• 제27권2호
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• pp.233-241
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• 2005

A sequence $\{f_i\}^{\infty}_{i=1}$ in a Hilbert space H is said to be exponentially localized with respect to a Riesz basis $\{g_i\}^{\infty}_{i=1}$ for H if there exist positive constants r < 1 and C such that for all i, $j{\in}N$, ${\mid}{\mid}{\leq}Cr^{{\mid}i-j{\mid}}$ and ${\mid}{\mid}{\leq}Cr^{{\mid}i-j{\mid}}$ where $\{{\tilde{g}}_i\}^{\infty}_{i=1}$ is the dual basis of $\{g_i\}^{\infty}_{i=1}$. It can be shown that such sequence is always a Bessel sequence. We present an additional condition which guarantees that $\{f_i\}^{\infty}_{i=1}$ is a frame for H.

• Macromolecular Research
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• 제17권4호
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• pp.221-226
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• 2009

The present study firstly describes the synthesis of novel, thermo-latent initiators based on xanthenyl phosphonium salts with different counter anions and phosphine moieties and secondly examines their efficiency in the bulk polymerization of glycidyl phenyl ether(GPE). The polymerization was performed with phosphonium salt initiators($I_{SbF6}$, $I_{PF6}$, $I_{AsF6}$ and $I_{BF4}$) at ambient temperature to $200^{\circ}C$ for 1 h. The order of initiator activity was $I_{SbF6}>I_{PF6}>I_{AsF6}>I_{BF4}$. To examine the effect of the phosphine moiety on the initiator activity, polymerization was carried out with $I_{SbF6}(Ph_{3}P)$ and $II_{SbF6}(Bu_{3}P)$ at ambient temperature to $170^{\circ}C$ for 1 h. The order of reactivity was $I_{SbF6}>II_{SbF6}$. In general, the conversion percentage increased with increasing polymerization temperature. The thermal stability of these salts was measured by thermo gravimetric analysis(TGA). The solubility of phosphonium salts in various organic solvents and epoxy monomers was also investigated.

• Kyungpook Mathematical Journal
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• 제59권4호
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• pp.689-702
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• 2019

Let 𝓐 and 𝓑 be real (or complex) algebras. We investigate the stability of a sequence F = {f₀, f₁, ⋯, f_n, ⋯ } of mappings from 𝓐 into 𝓑 satisfying the higher functional equation: $$f_n(x+y+zw)=f_n(x)+f_n(y)+\;{\normalsize\sum\limits_{\tiny{i+j=n \atop i{\leq}j}}}\;[f_i(z)f_j(w)+c_{ij}f_i(w)f_j(z)]$$ for each n = 0, 1, ⋯ and all x, y, z, w ∈ 𝓐, where $$c_{ij}=\left\{1{\text{ if }}i{\neq}j,\\0{\text{ if }}i=j.\right.$$.

• 대한수학회보
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• 제44권2호
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• pp.247-257
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• 2007

Consider the heteroscedastic regression model $Y_i=g(x_i)+{\sigma}_i\;{\epsilon}_i=(1{\leq}i{\leq}n)$, where ${\sigma}^2_i=f(u_i)$, the design points $(x_i,\;u_i)$ are known and nonrandom, and g and f are unknown functions defined on closed interval [0, 1]. Under the random errors $\epsilon_i$ form a sequence of NA random variables, we study the asymptotic normality of wavelet estimators of g when f is a known or unknown function.

• 산업경영시스템학회지
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• 제20권42호
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• pp.143-149
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• 1997

먼저 Cantor dust 의 성질 및 유사성, 축소인자, 불변집합, $\delta$ - covering, Box counting 차원 등에 대한 정의를 하였다, {f_i}{\;}{{\infty}\atop{i=1}}$ 를 $R^n$ 상에서 개집합 조건을 만족시키는 축소인 자 $C_i$에 대한 유사성 이라하자. F를｛{f_i}{\;}{{\infty}\atop {i=1}}$ 에 대한 $R^n$상의 불변집합, 즉, F = $\bigcup_{i=0}^\infty{\;}f_1(F)$를 만족시키는 집합이라 하자. 이때, $\sum\limits_{n=0}^\infty{\;}C^s_i{\;}=1,{\;}0{\;}<{\;}C_1{\;}<{\;}1$ 일 때, $dim{\;}_H{\;}F{\;}={\;}dim{\;}_B{\;}F{\;}={\;}s$ 임을 보임으로서, 자기동형집합의 후랙탈 차원에 대하여 논의 하고자 한다.

• Applied Biological Chemistry
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• 제49권1호
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• pp.25-29
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• 2006

하귤(Citrus natsudaidai Hayata)의 과피를 cold-press하여 얻어진 정유성분을 column chromatography, HPLC 및 TLC로 분리 정제하여 각 분획에 대하여 EBV활성화에 대한 억제효과를 측정하였다. Column chromatography로 정유성분의 분리를 시도하여 7개 의 peak$(F-I{\sim}VII)$를 얻을 수 있었다. 이것들을 TLC로 분석한 결과, 각각 단일 반점만을 나타냈으며 $R_f$값은 0.31, 0.13, 0.13 0.78, 0.79, 0.69, 0.84이었다. 7개의 peak중에서 F-I, II 및 F-IV 등 3개의 peak에 대하여 HPLC분석을 한 결과 F-I 및 F-II는 단일 peak이며 retention time은 F-I이 3분, F-II는 2.5분이었다. 그러나 F-IV는 2개의 peak가 나타났으며 retention time은 각각 2분과 4.5분이었다. 4.5분에 나타난 peak는 극히 적은 면적으로 보아 극소량의 물질이어서 앞서의 TLC분석에서 나타나지 많았던 것으로 생각된다. $F-I{\sim}F-VII$에 대한 EBV활성화에 대한 억제효과 측정은 Raji cells을 이용하여 간접형광 항체법으로 실시했다. 억제율은 F-VI가 $82.3{\pm}1.3%$으로 가장 높았으며 다음이 F-I$(80.4{\pm}1.6%)$ > F-II$(77.2{\pm}0.9%)$ > F-III$(75.0{\pm}1.2%)$ > F-IV$(74.1{\pm}1.0.%)$ > F-V$(71.0{\pm}1.1%)$ > F-VII$(70.2{\pm}1.2%)$의 순으로 모두 70% 이상의 억제율을 나타냈다. 이상의 결과는 하귤과피에는 발암 promotion 억제활성성분이 존재한다는 것을 시사한 것이다.

• Korean Journal of Mathematics
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• 제16권3호
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• pp.413-424
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• 2008

In [21], Th.M. Rassias proved that the norm defined over a real vector space V is induced by an inner product if and only if for a fixed integer $n{\geq}2$ $$n{\parallel}\frac{1}{n}\sum\limits_{i=1}^{n}x_i{\parallel}^2+\sum\limits_{i=1}^{n}{\parallel}x_i-\frac{1}{n}\sum\limits_{j=1}^{n}x_j{\parallel}^2=\sum\limits_{i=1}^{n}{\parallel}x_i{\parallel}^2$$ holds for all $x_1,{\dots},x_n{\in}V$. We consider the functional equation $$nf(\frac{1}{n}\sum\limits^n_{i=1}x_i)+\sum\limits_{i=1}^{n}f(x_i-\frac{1}{n}\sum\limits_{j=1}^{n}x_j)=\sum\limits_{i=1}^nf(x_i)$$ Using fixed point methods, we prove the generalized Hyers-Ulam stability of the functional equation $$(1)\;2f(\frac{x+y}{2})+f(\frac{x-y}{2})+f(\frac{y-x}{2})=f(x)+f(y)$$.

• Nuclear Medicine and Molecular Imaging
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• 제43권6호
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• pp.582-587
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• 2009

A 59-year-old woman who was diagnosed with malignant pheochromocytoma underwent $^{18}F$-fluorodeoxyglucose positron emission tomography/computed tomography ($^{18}F$-FDG PET/CT). She had undergone left adrenalectomy for pheochromocytoma 4 years previously. Recent multiple metastatic pulmonary nodules were noted on the chest X-ray. After treatment with $^{131}I$-metaiodobenzylguanidine ($^{131}I$-MIBG) with 7.4 GBq, post-therapy $^{131}I$-MIBG scintigraphy depicted multiple distant metastases including lung, liver, abdominal para-aortic and mesenteric lymph nodes. $^{18}F$-FDG PET/CT also depicted multiple metastases in lung, liver, and abdominal para-aortic lymph nodes, but some lesions were not shown. In this case, $^{131}I$-MIBG scintigraphy found additional lesions in metastatic malignant pheochromocytoma.

• Journal of Pharmaceutical Investigation
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• 제16권3호
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• pp.124-131
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• 1986

Pharmacological activities of Paeoniae Radix alba were studied with water extract (F-I), parched preparation (F-II) and 25% ethanol-treated preparation (F-III) of it. The results were summerized as follows; 1) Analgesic actions were recognized with F-I, F-II and F-III. 2) Sedative actions were recognized with F-I and F-III. 3) Prolonged effect of sleeping time were recognized significantly with F-I and F-III. 4) Antipyretic actions were recognized with F-1, F-II and F-III in rabbits. 5) F-I, F-II and F-III showed the antagonic action against contraction of isolated-ileum induced by acetylcholine, barium chloride and histamine in mice and guinea-pigs.