• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1192-1195
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• 1997

A divergent approach to 2-(hydroxymethyl)pyrrolidine-3,4-diols has been studied with 1,4-dideoxy-1,4-imino-D-arabinitol (D-AB1), a potent glycosidase inhibitor. D-AB1 was efficiently synthesized from 2,3-epoxyalcohol 6a in overall 11% yield.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.53-60
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• 2008

A test was conducted using two high density discharge lamps, the H2D and the structurally new H4D. They were tested for luminous illumination and luminous temperature in the day and night time. The test was conducted without crippling the performance of the H2D by adding a magnetic actuator, enabling it to move left to right, and up and down. By making these modifications we constructed a sample of the H4D. We compared the H2D and the H4D sample's luminous illumination and luminous temperature by using a photometer and a digital thermometer in the day and night time. We discovered that the H2D and H4D performed similarly from the data we gathered. Now we know the H4D has potential use and extensive research needs to be made to gather more detailed data.

• Archives of Pharmacal Research
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• v.20 no.3
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• pp.259-263
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• 1997

In the preparation of acyclic thymidine nucleoside analogues, $K_2CO_3$(or NaH) treated thymine in DMSO was alkylated with .omega.-chloroalkyl nitrite (Cl-(CH_2)n-CN; n=1, 2, 3, 4) to provide an isomeric mixture of 1-(${\omega}$-cyanoalkyl)thymine (2a-d) and 1,3-bis(${\omega}$-cyanoalkyl)thymine in approximately 5:1 ratios. Reduction of the cyano function 2a-d with $NaBH_{4}/CoCl_{2}$ center dot$ 6H_{2}O$gave the corresponding 1-(${\omega}$aminoalkyl)thymine (3a-d). The newly formed primary amino function in 3a-d was directly reacted with 2-chloroethylisocyanate to afford the 1-[.omega.($N^{I}$-2-chloroethylureido) alkyl]thymine (4a-d) in good yields. Nitrosation of 1-[5-($ N^{I}-2$-chloroethylureido)pentyl] thymine (4d) with glacial acetic acid and dry $NaNO_{2}$-powder in anhydrous $CH_{2}Cl_{2}$gave two types of regioisomeric nitrosoureas, 1-[5-($N^{I}$--chloroethyl-$N^{I}$--nitrosoureido)pentylithymine (5d) and 1-[5-($N^{I}-2$-chloroethyl-N-nitrosoureido)pentyllthymine in approximately 5 :1 ratios. The in vitro cytotoxicity of the synthesized compounds (2a-d, 3a-d, 4a-d and 5a-d) against three cell lines (K-562, P-388 and FM-3A) are measured as $IC^{50}$ values. Compounds 3b and 4c showed moderate activities against all three cell lines, and all other compounds were found to be not active.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.759-766
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• 2022

In this paper, we propose a multi-band small antenna with CPW(Coplanar Waveguide) feeding structure WLAN(Wireless Local Area Network) and WiMAX (Worldwide Interoperability for Microwave Access) bands. The proposed antenna is designed two slit in the modified monopole type radiator and FR-4 substrate, which is thickness 1.0 mm, and the dielectric constant is 4.4. The size of proposed antenna is 15.1 mm⨯16.41 mm, and total size of proposed antenna is 17.5 mm⨯16.4 mm. From the fabrication and measurement results, From the fabrication and measurement results, bandwidths of 439 MHz (2.06 to 2.499 GHz), 840 MHz (3.31 to 4.25) and 1,315 MHz (5.23 to 6.545 GHz) were obtained on the basis of -10 dB impedance bandwidth. Also, 3D radiation pattern characteristics of the proposed antenna are displayed and measured gains 2.24 dBi, 2.83 dBi, and 2.0 dBi shown in the three frequency band, respectively.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3793-3796
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• 2012

A novel 3D compound $\{[Cu(L)(H_2O)_4][Cu_2(SIP)_2(L)_2]\}{\cdot}2H_2O$ (1) (L = N,N-bis(4-pyridinecarboxamide)-1,4-butane, SIP = 5-sulfoisophthalate) is hydrothermally synthesized. X-ray diffraction analysis reveals that compound 1 is composed of 2D anionic $[Cu_2(SIP)_2(L)_2]_n{^{2n-}}$ double-layers and discrete 1D cationic $[CuL(H_2O)_4]_n{^{2n+}}$ polymeric chains, which represents a rare 3D polypseudo-rotaxane MOF from intercalation of 1D and 2D framework. In addition, the luminescent property and electrochemical behavior of compound 1 have been investigated.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.83-89
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• 2003

2,4-Dichlorophenoxyacetic acid (2,4-D) as a widely used herbicide has caused serious environmental problems because of its difficult decomposition in nature. We isolated the strain capable of metabolizing 2,4-D as sole carbon and energy source by an enrichment culture technique from the 2,4-D contaminated soil collected at orchard in Gwangju, Korea. This strain was identified tentatively as Aeromonas sp. NOH2. With this strain, we established the response surface methodology (Box-Behnken Design) to optimize the principle parameters for maximizing biodegradation of 2,4-D such as culture pH, temperature, and nutrient concentration in liquid batch culture. The ranges of parameters were obtained from preliminary works done at our laboratory and chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 5, 20, and 35 g/1 nutrient concentration. Initial concentration of 2,4-D was 500 ppm and nutrient source was tryptic soy broth. The experimental data were significantly fitted to a second order polynomial equation using multiple regression. The most important parameter influencing 2,4-D degradation and biomass production was nutrient concentration. For 2,4-D degradation, the optimum values of pH and temperature, and nutrient concentration were obtained at pH (6.5), temperature (31.8 to $32.1^{\circ}C$), and nutrient concentration (29.6 to 30.1.0 g/1).

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1310-1314
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• 2018

Non-Maxwellian distributions are found in the laboratory and space plasmas. For an accurate study of plasmas, the Kappa-averaged collision strengths of silicon VIII ion for $4^0S_{3/2}-2^0D_{3/2}$, $4^0S_{3/2}-2^0D_{5/2}$ and $2^0D_{3/2}-2^0D_{5/2}$ transitions are calculated for Kappa distributions with ${\kappa}=2$, 3 and 5 and for temperatures from $10^{4.5}K$ to $10^{6.5}K$. Results indicate that significant differences occur between the averaged collision strengths for the Maxwellian and the Kappa distributions. Fuythermore, and for each ${\kappa}$ value, the Kappa-averaged collision strengths vary in a complicated way with temperature for the $4^0S_{3/2}-2^0D_{3/2}$ and $4^0S_{3/2}-2^0D_{5/2}$ transitions while they decrease with increasing temperature for the $2^0D_{3/2}-2^0D_{5/2}$ transition. The calculation is significant if plasmas are to be studied for a non-Maxwellian distribution.

• Journal of Plant Biology
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• v.23 no.3_4
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• pp.91-98
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• 1980

In the present study effects of 2,4-D and kinetin on the callus tissue growth of Korean ginseng(Panax ginseng C. A. Meyer), in relation to the synthesis of saponin were investigated. The saponin synthesis in the callus culture of ginseng root was enhanced by 2,4-D and kinetin. The total saponin content of callus grown on the optima growth conditions, that is, 5mg/l of 2,4-D and 2mg/l of kinetin, was about three times as high as that of the 6 year-old ginseng roots commercially used as herbs. The kinetin specifically increased the synthesis of protopanaxadiol group ginsenoside and decreased the syntehsis of protopanaxatriol gropu in callus cultures, while 2,4-D caused to an increase in the synthesis of protopanaxatriol group ginsenoside and decrease the synthesis of protopanaxadiol group.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.27-30
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• 1989

Lithium has been intercalated into $FeMoO_4Cl$, and deintercalated from $LixFeMoO_4Cl$ both electrochemically and chemically. The inserted $Li^+$ ions are stabilized in the distorted octahedral field in interlayer space of $FeMoO_4Cl$. The crystal symmetry is reduced from tetragonal to monoclinic due to the reduction of ferric to ferrous ions in $LixFeMoO_4Cl$ upon lithium intercalation. From the magnetic and structural data, it has been concluded that the high-spin electronic configuration of $Fe^{2+}(d_{xz}^2{d_{y2}^1}{d_1}{2d_z^12}{\cdot}_y2)$, corresponding to $^5E_g$, group term in $D_{4h}$ symmetry, can be stabilized by the elongation of $FeO_4Cl_{2-}$octahedra in a weak ligand field.

• Kyungpook Mathematical Journal
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• v.53 no.2
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• pp.233-245
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• 2013

Let $\mathcal{A}$ be a Banach ternary algebra over a scalar field R or C and $\mathcal{X}$ be a ternary Banach $\mathcal{A}$-module. A quartic mapping $D\;:\;(\mathcal{A},[\;]_{\mathcal{A}}){\rightarrow}(\mathcal{X},[\;]_{\mathcal{X}})$ is called a $4^{th}$- order ternary derivation if $D([x,y,z])=[D(x),y^4,z^4]+[x^4,D(y),z^4]+[x^4,y^4,D(z)]$ for all $x,y,z{\in}\mathcal{A}$. In this paper, we prove Ulam stability generalizations of $4^{th}$- order ternary derivations associated to the following JMRassias quartic functional equation on fr$\acute{e}$che algebras: $$f(kx+y)+f(kx-y)=k^2[f(x+y)+f(x-y)]+2k^2(k^2-1)f(x)-2(k^2-1)f(y)$$.