• 대한수학회지
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• 제57권2호
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• pp.331-357
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• 2020

Let p be an analytic function defined on the open unit disk 𝔻. We obtain certain differential subordination implications such as ψ(p) := p^λ(z)(α+βp(z)+γ/p(z)+δzp'(z)/p^j(z)) ≺ h(z) (j = 1, 2) implies p ≺ q, where h is given by ψ(q) and q belongs to 𝒫, by finding the conditions on α, β, γ, δ and λ. Further as an application of our derived results, we obtain sufficient conditions for normalized analytic function f to belong to various subclasses of starlike functions, or to satisfy |log(zf'(z)/f(z))| < 1, |(zf'(z)/f(z))² - 1| < 1 and zf'(z)/f(z) lying in the parabolic region v² < 2u - 1.

• 대한수학회지
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• 제43권3호
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• pp.579-591
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• 2006

In this paper we obtain a sufficient and necessary condition for an analytic function f on the unit ball B with Hadamard gaps, that is, for $f(z)\;=\;{\sum}^{\infty}_{k=1}\;P_{nk}(z)$ (the homogeneous polynomial expansion of f) satisfying $n_{k+1}/n_{k}{\ge}{\lambda}>1$ for all $k\;{\in}\;N$, to belong to the weighted Bergman space $$A^p_{\alpha}(B)\;=\;\{f{\mid}{\int}_{B}{\mid}f(z){\mid}^{p}(1-{\mid}z{\mid}^2)^{\alpha}dV(z) < {\infty},\;f{\in}H(B)\}$$. We find a growth estimate for the integral mean $$\({\int}_{{\partial}B}{\mid}f(r{\zeta}){\mid}^pd{\sigma}({\zeta})\)^{1/p}$$, and an estimate for the point evaluations in this class of functions. Similar results on the mixed norm space $H_{p,q,{\alpha}$(B) and weighted Bergman space on polydisc $A^p_{^{\to}_{\alpha}}(U^n)$ are also given.

• 대한후두음성언어의학회지
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• 제12권1호
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• pp.55-60
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• 2001

Background and Objectives : Syllable Maximum Repetition Rate(MRR) is ability to repeat rapidly the articulators and is assessed for oromechanism function as one of the MPT. MRR is measured by rate(counts/sec), also simultaneously considered accuracy and consistency. The objective of the present was to examine stimuli effects and age and sex differences for MRR. Materials and Method : This study was participated 60 normal males and females(1 : 1) who were divided into two groups young(<40 years old) and old($\geq$40 years old). Stimuli were $/{P^=}a/,/{t^=}a/,/{k^=}a/,/{P^h}a/,/{t^h}a/,/{k^h}a/,/{P^=}{at^=}{ak^=}a/$ for, manner(tense and aspirated) of articulation, $/{p^h}{at^h}{ak^h}a/,/{t^h}{ap^h}{ak^h}a/$ for the effect of the order of syllable, glide /u-i/ for coordination of lip and tongue, interrupted vowel /i/ for laryngeal function. Results : There were little differences in two age groups and sex and manner of articulation for MRR tasks. The fastest average MRR of the single syllable included in this study was $/{t^=}a/$. significant differences existed between MRR for ${p^h}{at^h}{ak^h}a/ and /{t^h}{ap^h}{ak^h}a/$, which suggested that MRR was affected by the order of the syllables. MRR for interrupted vowel /i/ was about 2 counts/sec slower than average rate of 1 syllables. Conclusion : From these results, the order of the syllables was a crucial variable in MRR. rather than age or sex. There were no difference age, sex and manner of rate. The interrupted vowel repetition rate was slightly slow used and can provide basic information to assess the speech mechanism and can be useful to develop effective stimuli to differentiate the disordered group from normal.

• 한국잡초학회지
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• 제14권1호
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• pp.42-48
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• 1994

수수 줄기에 함유된 타감물질의 특성을 구명하기 위해서 극성, 비극성 용매로 분획한 결과 사용한 용매에 따라 억제 효과가 달리 나타났는데 ethyl ehter 분획에서 억제작용이 가장 크게 나타났으며 또 methylene chloride와 ethyl acetate 분획에서도 8mg/ml과 16mg/ml 농도에서 상당한 억제 효과가 나타났으나 hexane과 남은 수용층 분획에서는 거의 억제 효과가 나타나지 않았다. Ethyl ether 분획을 pH에 따라 알칼리성, 중성 및 산성으로 다시 분획한 결과 산성 분획에서 억제 효과가 가장 크게 나타났다. 이상의 결과에서 수수 줄기와 함유하고 있는 타감물질은 비극성이며 산성 특성을 가진 물질이라 추측된다.

• 대한화학회지
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• 제38권6호
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• pp.442-448
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• 1994

${\alpha}$-(n-Butyl)-N-Phenylnitrone 유도체의 첨가 반응속도상수를 25^{\circ}C$의 수용액에서 자외선 분광광도법으로 측정하여 넓은 pH범위에서 잘 맞는 반응속도식을 유도하였다. 첨가반응생성물은 ${\alpha}$-phenylthiobutylidene-aniline이었으며, 첨가반응속도상수 측정과 반응속도식의 유도, 일반기염 효과, 치환기 효과 및 최종생성물의 결과로부터 반응 메카니즘을 제안하였다. 즉, pH 3.0 이하에서는 티오페놀의 첨가로 반응이 시작되며, pH 3.0∼10.0에서는 티오페놀과 티오페녹시드 음이온이 경쟁적으로 첨가되어 진행되며, pH10.0이상에서는 티오페녹시드 음이온의 첨가에 의해서 반응이 진행된다.

• 생명과학회지
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• 제27권10호
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• pp.1145-1151
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• 2017

세제에 의하여 대장균의 periplasm에서 penicillin G amidase (PGA)를 방출하는 방법을 연구하였다. 결과적으로 세제와 lysozyme의 혼합 작용이 효과적인 것으로 나타났다. 세포 투과성의 최적 조건을 알아보기 위하여 세제의 종류, 농도, pH, 반응 시간, 온도 등의 영향을 살펴보았다. 그리하여 대장균에서 재조합 PGA를 periplasm에서 방출하는 모델을 만들 수 있었고 방출된 PGA를 농축할 수 있었다. 실리카 구슬을 이용한 고정화 시스템으로 PGA 용액을 농축할 수 있었으며, 더 이상의 정제 과정 없이 순수하게 추출 할 수 있었다. 고정화된 PGA는 penicillin G 생성의 원료인 6-APA를 생산하는데 사용할 수 있었다. 이 방법은 대장균으로부터 재조합 단백질을 추출하는 간단한 방법이며 고정화 PGA를 이용하여 ${\beta}-lactam$ 항생물질의 산업적 생산 이용될 수 있을 것으로 사료된다.

• 한국패류학회지
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• 제31권1호
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• pp.61-67
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• 2015

The occurrence of 'algal bloom', caused by the mass proliferation of phytoplankton, causes serious problems in streams and lakes in Korea. Therefore, in this study, the phytoplankton filter-feeding trait of Unio douglasiae, a type of freshwater clam, was used to reduce the algal bloom in outdoor water tanks during the summer. This involved the construction of a U. douglasiae cultivation apparatus, wherein 1,000 clams were divided into 8 rectangular baskets arranged in the shape of an empty square. The control tank was manufactured in exactly the same shape within the water tank, but without the addition of clams. The algal bloom-reducing effect of U. douglasiae was confirmed by the measurement of (and comparing between) the water quality at the center and periphery of the test and control cultivation apparatus. Water quality measurements included the measurement of water temperature, pH, turbidity, dissolved oxygen (DO) content, and chlorophyll-${\alpha}$ concentrations; the water quality was measured twice a month between June and November 2014.The results of these analyses did not show a significant difference in water quality (temperature, pH, turbidity, DO) between the center and periphery of the test and control tanks. However, the chlorophyll-${\alpha}$ concentration was observed to be much lower at the center of the test tank compared to that at the center and periphery of the control tank, as well as at the periphery of the test tank. This was believed to be a result of the U. douglasiae surrounding the center of the test tank, which prevented the influx of plankton from the periphery. Accordingly, the results of these analyses suggest the possibility that U. douglasiae cultivation could reduce the proliferation of algal blooms in lakes and streams during the summer. In particular, these results indicate possible improvements in U. douglasiae activity (reduction in algal blooms) by their effective arrangement in the water bodies.

• Journal of Microbiology and Biotechnology
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• 제24권4호
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• pp.545-555
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• 2014

It has been previously demonstrated that laccases exhibit great potential for use in several industrial and environmental applications. In this paper, two laccase isoenzyme genes, lccB and lccC, were cloned and expressed in Pichia pastoris GS115. The sequence analysis indicated that the lccB and lccC genes consisted of 1,563 and 1,584 bp, and their open reading frames encoded 520 and 527 amino acids, respectively. They had 72.7% degree of identity in nucleotides and 86.7% in amino acids. The expression levels of LccB and LccC were up to 32,479 and 34,231 U/l, respectively. The recombinant laccases were purified by ultrafiltration and $(NH_4)_2SO_4$ precipitation, showing a single band on SDS-PAGE, which had a molecular mass of 58 kDa. The optimal pH and temperature for LccB were 2.0 and $55^{\circ}C$ with 2,2'-azinobis-[ 3-ethylbenzthiazolinesulfonic acid (ABTS) as a substrate, whereas LccC exhibited optimal pH and temperature at 3.0 and $60^{\circ}C$. The apparent kinetic parameters of LccB were 0.43 mM for ABTS with a $V_{max}$ value of 51.28 U/mg, and the Km and $V_{max}$ values for LccC were 0.29 mM and 62.89 U/mg. The recombinant laccases were able to decolorize five types of dyes. Acid Violet 43 (100 g/ml) was completely decolorized by LccB or LccC (2 U/ml), and the decolorization of Reactive Blue KN-R (100 g/ml) was 91.6% by LccC (2 U/ml). Thus, the study characterizes useful laccase isoenzymes from T. versicolor that have the capability of being incorporated into the treatment of similar azo and anthraquinone dyes from dyeing industries.

• Asian-Australasian Journal of Animal Sciences
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• 제26권1호
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• pp.50-58
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• 2013

A facultative bacterium producing cellulolytic and hemicellulolytic enzymes was isolated from the rumen of a native Korean goat. The bacterium was identified as a Bacillus licheniformis on the basis of biochemical and morphological characteristics and 16S rDNA sequences, and has been designated Bacillus licheniformis JK7. Endoglucanase activities were higher than those of ${\beta}$-glucosidase and xylanase at all temperatures. Xylanase had the lowest activity among the three enzymes examined. The optimum temperature for the enzymes of Bacillus licheniformis JK7 was $70^{\circ}C$ for endoglucanase (0.75 U/ml) and $50^{\circ}C$ for ${\beta}$-glucosidase and xylanase (0.63 U/ml, 0.44 U/ml, respectively). All three enzymes were stable at a temperature range of 20 to $50^{\circ}C$. At $50^{\circ}C$, endoglucanse, ${\beta}$-glucosidase, and xylanase had 90.29, 94.80, and 88.69% residual activity, respectively. The optimal pH for the three enzymes was 5.0, at which their activity was 1.46, 1.10, and 1.08 U/ml, respectively. The activity of all three enzymes was stable in the pH range of 3.0 to 6.0. Endoglucanase activity was increased 113% by $K^+$, while $K^+$, $Zn^+$, and tween 20 enhanced ${\beta}$-glucosidase activity. Xylanase showed considerable activity even in presence of selected chemical additives, with the exception of $Mn^{2+}$ and $Cu^{2+}$. The broad range of optimum temperatures (20 to $40^{\circ}C$) and the stability under acidic pH (4 to 6) suggest that the cellulolytic enzymes of Bacillus licheniformis JK7 may be good candidates for use in the biofuel industry.

• 한국수산과학회지
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• 제33권1호
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• pp.79-85
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• 2000

굴 자숙농축액의 AOP에 의한 가수분해조건을 확립하였다. 자숙농축액에 대한 AOP의 작용조건은 $pH 7.0{\~}7.5$와 $50{\~}60{\circ}C$이었다. 그리고 효소 반응에 의한 반응시간에 따른 분해생성물의 양은 4 시간까지는 급격히 증가하였으며, 그 이후에는 완만하게 증가하였다. 굴 자숙액에 대하여 0.128 U의 A. oryzae PF protease를 첨가하여 최적조건에서 8 시간 가수분해시켜 가수분해물의 유리 아미노산을 분석한 결과 유리아미노산은 1.41배 증가하였다. AOP 처리에 의한 자숙액의 향미성분의 변화는 대부분의 alcohol, hydrocarbon, ester 및 함황 물질의 양은 증가한 반면에 aldehyde, ketone 화합물의 양은 감소하였으며, 특히 hydrocarbon 화합물의 증감은 분자량과 다소 관련이 있는 것으로 나타났다.