• Korean Journal of Agricultural Science
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• v.36 no.2
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• pp.135-145
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• 2009

This research was conducted to investigate the effect of various phosphorus concentrations in fertilizer solution on growth of and nutrient uptake by 'Chugyang' egg plant (Solanum melongena L.). Tissue and soil analyses were also conducted to set the threshold levels of phosphorus in plants when disorders develop for phosphorus deficiency or excess. Brown and purple areas developed on the margin of mature leaves and it enlarged rapidly in P deficient plants. The fruits in P deficient plants were small and dull purple in color. When P were excess in fertigation solution, the margins of lower leaves became scorched and it enlarged to inner part of the leaves. The fruits of P excess plants became small and had the curl shape. The tissue $PO_4$-P contents in the most recently fully expanded leaves and dry weight of full above ground plant tissue at 35 days after transplanting showed quadratic response ($y=0.7887+0.2394x-0.0197x^2$) and cubic response ($y=10.43+14.47x-4.7642x^2+0.3977x^3$) to elevated $PO_4$-P concentrations, respectively. When 10% reduction in dry weight set to threshold levels, optimum tissue $PO_4$-P contents are between 0.98 to 1.35%. The yield determined at 150 days after transplanting also showed cubic response to elevated phosphorus concentrations in fertigation solution ($y=1194.6+1502.2x-454.5x^2+35.64x^3$). When the 10% reduction in yield is set to threshold levels, the tissue $PO_4$-P contents for maximum yield should be around 1.53% to 2.25% in most recently fully expanded leaves at 150 days after transplanting.

• Macromolecular Research
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• v.15 no.4
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• pp.302-307
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• 2007

The living radical polymerization of methyl methacrylate (MMA) by atom transfer radical polymerization, (ATRP) employing a $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine (PyP) catalytic system (X=Cl, Br), was investigated using several initiators and solvents at various temperatures. Most of the polymerizations with the PyP ligand were well controlled, with a linear increase in the number average molecular weights ($M_n$) vs. conversion, with relatively low molecular weight distributions ($M_w/M_n=1.2-1.4$) throughout the reactions. The measured weights matched those of the predicted values. The ethyl-2-bromoisobutyrate (EBriB) initiated ATRP of MMA, with the $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine catalytic system (X=Cl, Br), was better controlled in p-xylene at $80^{\circ}C$ than the other solvents used in this study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.169-170
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• 2005

본 연구에서는 초음파 센서에 응용 가능한 $0.4Pb(Ni_{1/3}Nb_{2/3})O_3-0.6Pb(Zr_xTi_{1-x})O_3+0.5Wt%$ $MnO_2$ 세라믹스에 Zr/(Ti+Zr)비를 0.37에서 0.41로 변화시킨 조성을 1175 $\sim$ 1200$^{\circ}C$ 온도에서 소결하여 이의 결정구조 및 미세조직을 분석하였고, 압전, 유전 특성을 고찰하였다. 본조성에서 x=0.385 조성에서 최대 유전상수 값 3490 이 나타났으며, 그 이상의 첨가에서는 감소하였다. 상경계 영역인 x=0.385 조성에서 $\varepsilon$r, $K_p$, $d_{33}$ 값이 최대값을 나타내었다. $0.4Pb(Ni_{1/3}Nb_{2/3})O_3-0.6Pb(Zr_xTi_{1-x})O_3+0.5Wt%$ $MnO_2$, 세라믹스에서는 kp 와 $d_{33}$ 는 Zr/(Ti+Zr)비 0.385조성까지 증가하였다가 그 이상 조성에서 감소하였다. $1175^{\circ}C$에서 2시간 소결한 x=0.385조성에서 $\varepsilon$r=3490, kp=0.71, Qm=476의 우수한 압전 특성을 나타내었다.

• Archives of Pharmacal Research
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• v.29 no.11
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• pp.1032-1041
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• 2006

Extracellular adenosine 5'-triphosphate (ATP) affects the function of many tissues and cells. To confirm the biological activity of ATP on human myeloid leukemic cells, F-36P and HL-60, cells were treated with a variety of concentrations of ATP. The stimulation with extracellular ATP induced the arrest of cell proliferation and cell death. from the analysis of Annexin-V staining and caspase activity by flow cytometry. The Annexin-V positive cells in both cell lines were dramatically increased following ATP stimulation. The expression of P2 purinergic receptor genes was confirmed, such as P2X1, P2X4, P2X5, P2X7 and P2Y1, P2Y2, P2Y4, P2Y5, P2Y6, P2Y11 in both leukemic cell lines. Interestingly, ATP induced intracellular calcium flux in HL-60 cells but not in F-36P cells, as determined by Fluo-3 AM staining. Cell cycle analysis revealed that ATP treatment arrested both F-36P and HL-60 cells at G1/G0. Taken together, these data showed that extracellular ATP via P2 receptor genes was involved in the cell proliferation and survival in human myeloid leukemic cells, HL-60 and F-36P cells by the induction of apoptosis and control of cell cycle. Our data suggest that treatment with extracellular nucleotides may be a novel and powerful therapeutic avenue for myeloid leukemic disease.

• Bulletin of the Korean Mathematical Society
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• v.55 no.4
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• pp.1209-1219
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• 2018

We provide a direct proof of the following theorem of Kalton, Hollenbeck, and Verbitsky [7]: let H be the Hilbert transform and let a, b be real constants. Then for 1 < p < ${\infty}$ the norm of the operator aI + bH from $L^p(\mathbb{R})$ to $L^p(\mathbb{R})$ is equal to $$\({\max_{x{\in}{\mathbb{R}}}}{\frac{{\mid}ax-b+(bx+a){\tan}{\frac{\pi}{2p}}{\mid}^p+{\mid}ax-b-(bx+a){\tan}{\frac{\pi}{2p}}{\mid}^p}{{\mid}x+{\tan}{\frac{\pi}{2p}}{\mid}^p+{\mid}x-{\tan}{\frac{\pi}{2p}}{\mid}^p}}\)^{\frac{1}{p}}$$. Our proof avoids passing through the analogous result for the conjugate function on the circle, as in [7], and is given directly on the line. We also provide new approximate extremals for aI + bH in the case p > 2.

• Honam Mathematical Journal
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• v.33 no.4
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• pp.467-485
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• 2011

We consider the Hyers-Ulam-Rassias stability problem $${\parallel}u{\circ}A-{\upsilon}{\circ}P_1-w{\circ}P_2{\parallel}{\leq}{\varepsilon}({\mid}x{\mid}^p+{\mid}y{\mid}^p)$$ for the Schwartz distributions u, ${\upsilon}$, w, which is a distributional version of the Pexider generalization of the Hyers-Ulam-Rassias stability problem ${\mid}(x+y)-g(x)-h(y){\mid}{\leq}{\varepsilon}({\mid}x{\mid}^p+{\mid}y{\mid}^p)$, x, $y{\in}\mathbb{R}^n$, for the functions f, g, h : $\mathbb{R}^n{\rightarrow}\mathbb{C}$.

• The Pure and Applied Mathematics
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• v.15 no.4
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• pp.393-400
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• 2008

In this paper, we investigate the following additive functional inequality (0.1) ||f(x)+f(y)+f(z)+f(w)||${\leq}$||f(x+y)+f(z+w)|| in normed modules over a $C^*$-algebra. This is applied to understand homomor-phisms in $C^*$-algebra. Moreover, we prove the generalized Hyers-Ulam stability of the functional inequality (0.2) ||f(x)+f(y)+f(z)f(w)||${\leq}$||f(x+y+z+w)||+${\theta}||x||^p||y||^p||z||^p||w||^p$ in real Banach spaces, where ${\theta}$, p are positive real numbers with $4p{\neq}1$.

• Honam Mathematical Journal
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• v.32 no.4
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• pp.537-544
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• 2010

We prove the superstability of a functional inequality associated with general exponential functions as follows; ${\mid}f(x+y)-a^{x^2y+xy^2}g(x)f(y){\mid}{\leq}H_p(x,y)$. It is a generalization of the superstability theorem for the exponential functional equation proved by Baker.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.311-316
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• 2010

It is well-known that electrical field stimulation (EFS)-induced contraction is mediated by a cholinergic mechanism and other neurotransmitters. NO, ATP, calcitonin gene-related peptide (CGRP), and substance P are released by EFS. To investigate the purinergic mechanism involved in the EFS-induced contraction, purinegic receptors antagonists were used. Suramine, a non-selective P2 receptor antagonist, reduced the contraction induced by EFS. NF023 ($10^{-7}{\sim}10^{-4}M$), a selective P2X antagonist, inhibited the contraction evoked by EFS. Reactive blue ($10^{-6}{\sim}10^{-4}M$), selective P2Y antagonist, also blocked the contraction in a dose-dependent manner. In addition, P2X agonist ${\alpha}$,${\beta}$-methylene 5'-adenosine triphosphate (${\alpha}{\beta}MeATP$, $10^{-7}{\sim}10^{-5}M$) potentiated EFS-induced contraction in a dose-dependent manner. P2Y agonist adenosine 5'-[${\beta}$-thio]diphosphate trilithium salt ($ADP{\beta}S$, $10^{-7}{\sim}10^{-5}M$) also potentiated EFS-induced contractions in a dose-dependent manner. Ecto-ATPase activator apyrase (5 and 10 U/ml) reduced EFS-induced contractions. Inversely, 6-N,$N$-diethyl-D-${\beta}$,${\gamma}$- dibromomethylene 5'-triphosphate triammonium (ARL 67156, $10^{-4}M$) increased EFS-induced contraction. These data suggest that endogenous ATP plays a role in EFS-induced contractions which are mediated through both P2X-receptors and P2Y-receptors stimulation in cat esophageal smooth muscle.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.967-974
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• 2003

This experiment was carried out to investigate the relationship of morphological characteristics between reticulum and abomasum of Korean native young goats age from 2 days to 150 days. Number of traits investigated in the reticulum in this experiment were 12[body weight, chest girth, body length, right and left reticulum length(R.L.), upper and lower reticulum length(U.L.), reticulum weight(R.W.), reticulum area(R.A.), upper and lower length of one polygon located at central part of reticulum(U.P.C.R.), right and left length of one polygon located at central part of reticulum(R.P.C.R.), thickness of polygon wall located at central part of reticulum(T.P.C.R.), thickness of polygon wall located at middle part of reticulum(T.P.M.R.), and thickness of polygon wall locared at edge part of reticulum(T.P.E.R.)] and items for abomasum were 12[length of between ostium omaso-abomasicum part and pylosica part in the abomasum(L.B.O.P.), broadest outer part of the abomasum(B.O.A.), weight of abomasum(W.O.A.), area of abomasum(A.O.A.), number of plicae abomasi in the abomasum(N.P.A.A.), thickness of abomasum well at cranial part(ostium omasoabomasicum) in the abomasum(T.A.C.A.), thickness of abomasum well at central part in the abomasum(T.A.P.A.), thickness of abomasum wall at light upper area of pylosica part in the abomasum(T.A.L.A.), length measured from the longest plica abomasi in the abomasum(L.L.P.A.), broadest measured from the longest plica abomasi in the abomasum(B.L.P.A.), area measured from the longest plica abomasi in the abomasum(A.L.P.A.), weight of longest plica abomasi in the abomasum(W.L.P.A.)]. The results were summarized as follows: 1. Number of coefficient of correlation obtained among 12 traits of the abomasum and 12 of the reticulum were 144, and coefficient of correlation of 114 were significant(P〈0.05). 2. Trait of abomasum weight have high correlation with 12 traits of reticulum. 3. Correlation coefficients and regression equation between body weight. VS. abomasum weight(r$_1$), and upper and lower length of one polygon located at central part of reticulum(U.P.C.R.) VS. abomasum weight(r$_2$) were r$_1$=0.8954$^{**}$ and Y=10.703+3.374X, r$_2$=0.8430$^{**}$ and Y=5.689+4.311X, respectively. 4. Correlation coefficients and regression equation between chest girth VS. abomasum weight(r$_1$), and body weight VS. abomasum weight(r$_2$) were r$_1$=0.8708$^{**}$ and Y=-17.219+1.227X, r$_2$=0.8589$^{**}$ and Y=- 17.616+1.290X, respectively.