• 충청수학회지
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• 제23권2호
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• pp.231-236
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• 2010

Using the properties of the concave function, we show that the Hausdorff dimension of the product $C_{\frac{a+b}{2},\frac{a+b}{2}}{\times}C_{\frac{a+b}{2},\frac{a+b}{2}}$ of the same symmetric Cantor sets is greater than that of the product $C_{a,b}{\times}C_{a,b}$ of the same anti-symmetric Cantor sets. Further, for $1/e^2$ < a, b < 1/2, we also show that the dimension of the product $C_{a,a}{\times}C_{b,b}$ of the different symmetric Cantor sets is greater than that of the product $C_{\frac{a+b}{2},\frac{a+b}{2}}{\times}C_{\frac{a+b}{2},\frac{a+b}{2}}$ of the same symmetric Cantor sets using the concavity. Finally we give a concrete example showing that the latter argument does not hold for all 0 < a, b < 1/2.

• 수산해양교육연구
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• 제12권2호
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• pp.191-198
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• 2000

이 연구는 제주도 연안에 분포되어 있는 정치망에서 음향 집어기에 의한 어류의 유집에 대한 기초 자료를 제공할 목적으로, 정치망의 주요 어획 대상 어류인 독가시치를 선택하여, 가청 수중음과 전기 자극을 이용하여 음향 조건학습시켰으며, 주파수와 음압을 변화시켜가면서 심전도를 도출하여 심박 간격의 변화로부터 청각 능력을 알아내는 방법을 이용하여, 독가시치의 청각 문턱치 및 청각 임계비를 측정 조사 한 결과 75, 79, 83의 3단계 백색잡음을 방성하였을 때 독가시치의 청각 문턱치는 백색잡음이 없을 때보다 높게 나타나 마스킹 효과가 나타났고, 측정주파수 200Hz, 300Hz에서 보다 뚜렷하게 나타났다. 독가시치의 청각 임계비는 측정주파수 80, 100, 200, 300, 500, 800Hz에서 대략 28, 23, 31, 34, 40, 52dB이고 마스킹 현상은 음압이 약 70dB 이상의 잡음레벨에서 나타나기 시작하였고 측정주파수 100 - 200Hz에서 신호음을 인식하기 위해서는 음압이 대략 98dB이상, 배경잡음레벨보다 약 23dB이상의 높은 음압이 요구되었다.

• 한국자기학회지
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• 제5권1호
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• pp.34-37
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• 1995

단롤법 급속응고장치를 이용하여 비정질 $Nd_{x}Fe_{77}B_{23-x}(x=4,\;6,\;8,\;11,\;13)$ 합금을 제작하고 $650^{\circ}C$ 이상에서 결정화 시키어 자기적 특성을 조사하였다. 열처리 후의 결정상을 조사한 결 과 x=8 조성에서 준안정상 $Nd_{2}Fe_{23}B_{3}$가 단일상에 가깝게 생성되며 연자기특성을 나타냄 을 알았다. 자기특성 조사결과 $8{\leq}x{\leq}13$ 조성범위에서 Nd 함유량이 증가할수록 보자력은 증가하나 잔류자속밀도는 감소함을 알았다. 그러나, $4{\leq}x{\leq}6$ 합금의 경우 Nd 함유량이 감소할수록 보자 력과 잔류자속밀도가 함께 증가하였다. x=4 합금의 경우 연자성:경자성=70:30의 혼합조직이 얻어지며 $96kJ/m^{3}(12MGOe)$의 높은 에너지적을 나타냈다.

• Journal of Gastric Cancer
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• 제22권4호
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• pp.348-368
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• 2022

Purpose: Chromosomal instability is a hallmark of gastric cancer (GC). It can be driven by single nucleotide variants (SNVs) in cell cycle genes. We investigated the associations between SNVs in candidate genes, PLK2, PLK3, and ATM, and GC risk and clinicopathological features. Materials and Methods: The genotyping study included 542 patients with GC and healthy controls. Generalized linear models were used for the risk and clinicopathological association analyses. Survival analysis was performed using the Kaplan-Meier method. The binding of candidate miRs was analyzed using a luciferase reporter assay. Results: The PLK2 C_rs15009-C_rs963615 haplotype was under-represented in the GC group compared to that in the control group (P_corr=0.050). Male patients with the PLK2 rs963615 CT genotype had a lower risk of GC, whereas female patients had a higher risk (P=0.023; P=0.026). The PLK2 rs963615 CT genotype was associated with the absence of vascular invasion (P=0.012). The PLK3 rs12404160 AA genotype was associated with a higher risk of GC in the male population (P=0.015). The ATM T_rs228589-A_rs189037-G_rs4585 haplotype was associated with a higher risk of GC (P<0.001). The ATM rs228589, rs189037, and rs4585 genotypes TA+AA, AG+GG, and TG+GG were associated with the absence of perineural invasion (P=0.034). In vitro analysis showed that the cancer-associated miR-23b-5p mimic specifically bound to the PLK2 rs15009 G allele (P=0.0097). Moreover, low miR-23b expression predicted longer 10-year survival (P=0.0066) in patients with GC. Conclusions: PLK2, PLK3, and ATM SNVs could potentially be helpful for the prediction of GC risk and clinicopathological features. PLK2 rs15009 affects the binding of miR-23b-5p. MiR-23b-5p expression status could serve as a prognostic marker for survival in patients with GC.

• Archives of Pharmacal Research
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• 제25권5호
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• pp.608-612
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• 2002

The twelve-protostane analogues were synthesized from alisol B 23-acetate and assessed for their in vitro antitumor activity against six different human and murine tumor cell lines. Of the compounds synthesized, 23S-acetoxy-24R(25)-epoxy-11$\beta$,23S-dihydroxyprotost-13(17)-en-3-hy-droxyimine (12) exhibited significant cytotoxic activities against A549, SK-OV3, B16-F10, and HT1080 tumor cells with $ED_{50}/$ values of 10.0, 8.7 ,5.2, and 3.1 ${\mu}g$/ml, respectively. Furthermore, 23S-acetoxy-13(17),24R(25)-diepoxy-11$\beta$-hydroxyprotost-3-one (5), 13(17),24R(25)-diepoxy-11$\beta$, 23S-dihydroxyprotostan-3-one (6), 24R,25-epoxy-11$\beta$,23S-dihydroxyprotost-13(17)-en-3-one (7), and 11$\beta$,23S,24R,25-tetrahydroxyprotost-13(17)-en-3-one (9) showed moderate cytotoxic activities against 816-F10 and HT1080 tumor cells. These results mean that a hydroxyimino group at C-3 position in the protostane-type terpene enhances cytotoxic activity.

• 생약학회지
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• 제40권3호
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• pp.238-243
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• 2009

We examined ethanol extracts prepared from 23 Korean local plants obtained in Pyeongchang, Gangwon-do for their inhibitory effects on recombinant human AKR 1 B10 (rhAKR1B10) in vitro. To do this, rhAKR1B10 was first expressed in E. coli as a biological active form and purified by using Ni-affinity chromatography followed by gel permeation chromatography. Then, rhAKR1B10 was used for screening out 23 Korean local plant extracts having an inhibitory activity against itself. Among them, six extracts showed more than 50% inhibition of rhAKR1B10 activity at the concentration of $10{\mu}g$/ml. Especially, the extracts of Ligularia fischeri var. spiciformis Nakai and Rhus trichocarpa Miq. were the most potent because their $IC_{50}$ values were 2.94 and $2.00{\mu}g$/ml, respectively.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제23권1호
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• pp.61-72
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• 2016

In this paper, a boundary version of the Schwarz lemma for the holom- rophic function satisfying f(a) = b, |a| < 1, b ∈ ℂ and ℜf(z) > α, 0 ≤ α < |b| for |z| < 1 is invetigated. Also, we estimate a modulus of the angular derivative of f(z) function at the boundary point c with ℜf(c) = a. The sharpness of these inequalities is also proved.

• 천문학회지
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• 제10권1호
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• pp.3-12
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• 1977

$Str\ddot{o}mgren$-system colors for 23 OV stars compiled by Crawford have been compared with colors calculated by Mihalas from non-LTE model atmospheres. In this way, effective temperatures of these stars have been determined and plotted against spectral type, $c_1$ (u-b), (b-y), (U-B), and (B-V). Within the accuracy of the observations, effective temperatures derived from the photometry for these 23 main-sequence stars are found to be in good agreement with Contiis spectroscopical temperatures.

• 한국정보통신학회논문지
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• 제11권8호
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• pp.1415-1423
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• 2007

본 연구에서는 GSM1900 주파수 대역을 위한 이동통신 기지국용 Isohybrid를 개발함으로써 시스템의 효율을 증가시켰으며 제품의 소형화 및 안정된 특성을 구현하였다. 결과로서 각각 Chip coupler type과 Hybrid coupler type의 Isohybrid transmitter combiner를 설계 및 제작하였고 Insertion loss는 Chip coupler type Isohybrid의 경우에 $3.29\;dB{\sim}3.47\;dB$로 측정되었으며 Hybrid coupler type의 경우에는 $3.17\;dB{\sim}3.42\;dB$로 측정되어 3.5 dB 미만을 만족하였다. ANT단과 Port단 사이의 Isolation은 Chip coupler type Isohybrid의 경우에 $24.23\;dB{\sim}29.98\;dB$로 측정되었으며 Hybrid coupler type의 경우에는 $26.28\;dB{\sim}36.91\;dB$로 측정되어 23 dB 이상의 우수한 특성을 확인하였다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.23-23
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• 2015

Rice blast disease caused by M. oryzae is the most devastating fungal disease in rice. During the infection process, M. oryzae secretes a large number of glycosyl hydrolase (GH) proteins into the apoplast to digest host cell wall and assist fungal ingress into host tissues. In this study, we identified a novel M. oryze arabinofuranosidase B (MoAbfB) which is secreted during fungal infection. Live-cell imaging exhibited that fluorescent labeled MoAbfB was highly accumulated in fungal invasive structures such as appressorium, tips of penetration peg, biotrophic interfacial complex (BIC), as well as invasive hyphal tip. Deletion of MoAbfB mutants extended biotrophic phase followed by enhanced disease severity, whereas, over-expression of OsMoAbfB mutant induced rapid defense responses and enhanced rice resistance to M. oryzae infection. Furthermore, exogenous treatment of MoAbfB protein showed inhibition of fungal infection via priming of defense gene expression. We later found that the extract of MoAbfB degraded rice cell wall fragments could also induce host defense activation, suggesting that not MoAbfB itself but oligosaccharides (OGs) derived from MoAbfB dissolved rice cell wall elicited rice innate immunity.