• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.516-523
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• 2015

This study investigated the antimutagenic and anticancer effects of Platycodon grandiflorum extract (PGE) and its fractions against carcinogenic N-nitrosodimethylamine (NDMA) and genotoxicity. The Ames Salmonella mutagenicity test employing histidine mutants of Salmonella Typhimurium TA98 and TA100 was used to examine the mutagenicity of PGE and its fractions. Bacterial reversion assay with S. Typhimurium TA98 and TA100 did not show a significantly increased number of revertant colonies. The same test was used to examine the ability of PGE and its fractions to prevent acquisition of N-methyl-N'-nitro-N-nitrosoguanidine- and 4-introquino-line-1-oxide-induced mutations. PGE and its fractions inhibited mutagenesis in a dose-dependent manner. Among the fractions, ethyl acetate fraction from PGE (PGEA) exhibited a higher antimutagenic effect than other fractions. PGE and its fractions suppressed the growth of cancer cell lines, including human cervical adenocarcinoma, human hepatocellular carcinoma, human breast adenocarcinoma, human lung carcinoma, and transformed primary human embryonic kidney cells. In addition, we evaluated the antitumor activity of PGEA and its fractions in sacorma-180 solid tumor-bearing mice. In vivo anticancer activity results showed that PGE and its fractions could more effectively suppress tumor growth than the control. PGEA showed higher in vitro and in vivo anticancer effects than PGE and other fractions, and PGEA inhibited NDMA formation. Thus, we showed that PGEA has antimutagenic and anticancer activities, making it a candidate anticancer material under these experimental conditions.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.1
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• pp.14-18
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• 2016

A novel $Ce^{3+}$ doped $(Ce_xLu_{1-x})_3MgAl_3SiO_{12}$ phosphor was successfully synthesized by a conventional solid-state reaction. Heat-treatment temperature was controlled from 1250 to $1550^{\circ}C$ for 5 h. XRD and PL properties were analyzed for the optimum heat-treatment condition. Ce doping concentration was varied from 2.0 to 10.0 mol% for the optimum Ce doping concentration. The PL intensity, peak wavelength and FWHM were calculated with the Ce doping concentration, and evaluated for the application to LED packaging. Particle size and morphology were also characterized for synthesized phosphor sample at optimum heat-temperature and Ce doping concentration.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.4
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• pp.202-207
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• 2009

Nanocomposite formation of metal-metal oxide systems by mechanical alloying (MA) has been investigated at room temperature. The systems we chose are the $Fe_3O_4$-M (M = AI, Ti), where pure metals are used as reducing agent. It is found that $Fe/Al_2O_3$ and $Fe/TiO_2$ nanocomposite powders in which $Al_2O_3$ and $TiO_2$ are dispersed in ${\alpha}$-Fe matrix with nano-sized grains are obtained by MA of $Fe_3O_4$ with Al and Ti for 25 and 75 hours, respectively. It is suggested that the shorter MA time for the nanocomposite formation in $Fe/Al_2O_3$ is due to a large negative heat associated with the chemical reduction of magnetite by aluminum. X-ray diffraction results show that the average grain size of ${\alpha}$-Fe in $Fe/TiO_2$ nanocomposite powders is in the range of 30 nm. The change in magnetic properties also reflects the details of the solid-state reduction of magnetite by pure metals during MA.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.387-393
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• 2007

We examined the conditions for separating and preserving the male and female gametophytes of Kjellmaniella crassifolia. The highest percentage of zygote germination (85%) was on semi-solid medium composed of 1.0% transfer gel agar at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ after a 4-week culture. Zygote germination in PESI liquid medium was 93.5% at $20\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$. The maximum zygote growth was $252{\pm}19.7\;{\mu}m$ on 1.0% transfer gel agar at $15\;^{\circ}C$ and $40\;{\mu}mol/m^2/s$ after 5-week culture, and was $76.7{\pm}2.8\;{\mu}m$ in PESI liquid medium at $20\;^{\circ}C$ and $40\;{\mu}mol/m^2/s$. The respective numbers of separated male and female gametophytes from germinated zygotes were 157 and 93 on 1.0% transfer gel agar and 14 and 28 in PESI liquid medium. The maximum growth of separated male and female gametophytes was $575{\pm}28.3\;{\mu}m$ at $5\;^{\circ}C$ and $60\;{\mu}mol/m^2/s$ and $686{\pm}35.4\;{\mu}m$ at $20\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ in PESI liquid medium after 3 weeks, respectively. The highest percentage fertilized was $93.3{\pm}5.8%$ at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ in PESI liquid medium. These results show that the best conditions for the separation and preservation of gametophytes (male and female) consisted of culturing on 1.0% transfer gel agar at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.4
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• pp.292-296
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• 2000

Mechenochemical reaction by planetary type ball mill is applied to prepare $Sm_2$$Fe_{17}$$N_{x}$ permanent magnet powders. Starting from pure samarium and iron powders, the formation process of hard magnetic $Sm_2$$Fe_{17}$$N_{x}$ phase by ball milling and a subsequent solid state reaction were studied. At as-milled stage powders were found to consist of amorphous Sm-Fe and $\alpha$-Fe phases in all composition of $Sm_2$$Fe_{100-x}$(x = 11, 13, 15). The dependence of starting composition of elemental powder on the formation of Sm-Fe intermetallic compound was investigated by heat treatment of as-milled powders. When Sm concentration was 15 at%, heat-treated powder consists of mostly $Sm_2$$Fe_{17}$$N_{x}$single phase. For synthesizing of hard magnetic $Sm_2$$Fe_{17}$$N_{x}$ compound, additional nitriding treatment was carried out under $N_2$gas atmosphere at $450^{\circ}C$. The increase in the coercivity and remanence was parallel to the nitrogen content which increased drastically at first and then gradually as the nitriding time was extended. The ball-milled Sm-Fe-N powders were expected to be prospective materials for synthesizing of permanent magnet with high performance.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.3
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• pp.109-114
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• 2008

Novel green long persistent phosphors of $CaZrO_3$ : $HO_{3+}$ have been synthesized at high temperature with weak reduction atmosphere by traditional solid state reaction method. The role of $H_3BO_3$ as flux and the suitable concentration of Ho as activator on the $CaZrO_3$ : $HO_{3+}$ long persistent phosphors has been investigated. Crystals of $HO_{3+}$ doped $CaZrO_3$ long persistent phosphores were characterized by fluorescence spectrophotometer and photoluminescence (PL). The main emission spectra of 546 nm peak was revealed through synthesizing at high temperature in $N_2$ gas atmosphere. The after glow emission spectra of $CaZrO_3$ : $HO_{3+}$ long persistent phosphores arise at 546 nm peak of narrow range. because that revealed pure green color. Green long persistent phosphors have been observed in the system for over 5 h after UV irradiation (254 nm). The main emission peak was ascribed to $HO_{3+}$ ions transition from $^5F_4$, $^5S_2{\to}^5I_3$, and the after glow may be ascribed to the trap centers in the $CaZrO_3$ host lattice.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.1
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• pp.51-57
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• 2013

We have applied mechanical alloying (MA) to produce Heusler $Fe_2VAl$ thermoelectric alloy using a mixture of elemental $Fe_{50}V_{25}Al_{25}$ powders. An optimal milling and heat treatment conditions to obtain the single phase of Fe2VAl compound with fine microstructure were investigated by X-ray diffraction and differential scanning calorimetry (DSC) measurement. The $Fe_{50}V_{25}Al_{25}$ MA sample ball-milled for 60 hours exhibits a bcc ${\alpha}$-(Fe,V,Al) solid solution. Single phase of Heusler $Fe_2VAl$ compound can be obtained by MA of $Fe_{50}V_{25}Al_{25}$ mixture for 60 hours and subsequently heated up to $700^{\circ}C$. Sintering of the MA powders was performed in a spark plasma sintering (SPS) machine using graphite dies at $900{\sim}1000^{\circ}C$ under 60 MPa. The Vickers hardness of bulk sample sintered at $1000^{\circ}C$ was high value of Hv 870. All compact bodies have a high relative density above 90 % with metallic glare on the surface.

• Journal of Aquaculture
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• v.14 no.4
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• pp.221-226
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• 2001

The ethanol extract of root bark of Morus alba strongly inhibited the Gram positive bacteria like Streptococcus sp., Lactococcus garvieae and Staphylococcus sp., but weakly the Gram negative bacteria like Listonella anguillarm and Edwardsiella tarda. It was more effective in liquid medium than in solid medium. The minimum inhibition concentration (MIC) of the extract in liquid medium was 19.8 and 790~1185 $\mu\textrm{g}$/$m\ell$ for the Gram positive and Gram negative bacteria, respectively. The extract concentration, at which the growth was totally inhibited, was 67.2~403.0 $\mu\textrm{g}$/$m\ell$ for the Gram positive bacteria but it was as high as 1185 $\mu\textrm{g}$/$m\ell$ for L. anguillarum and almost ineffective against E. tarda. For diet supplementation of the extract, effective soaking duration was 3 minutes. The fish diet soaked in the extract inhibited the growth of all the tested Gram positive strains, but not the Gram negative strains. The relationship between the weight of fish diet and absorption of the extract by the fish diet was Y=7.5757X + 4.6962($R^2$ = 0.9998).

• Korean Journal of Organic Agriculture
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• v.18 no.1
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• pp.63-74
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• 2010

The present study was carried out to evaluate the effects of organic liquid fertilizer (OLFs) fertigation on the growth and fruit quality of hot pepper (Capsicum annuum L.) cv. 'Nokkwang (Seminis Korea)'. Treatments were given with control (chemical feritilzer), OLF I(fowl dropping : fish meal : soybean meal, 2:1:1), OLF II(fowl dropping : bone meal : soybean meal, 2:1:1), OLF III(fowl dropping : bone meal, 1:1), and OLF IV(fowl dropping : rice bran : soybean meal, 2:1:1). The composition ratio of OLF based on weight to weight. The pH and EC of OLFs according to different material and compositions ranged from 6.5 to 6.8, and from 2.91 to $3.69dS{\cdot}m^{-1}$, respectively. The C/N ratio was the highest as 5.75 in OLF Ⅳ, and there was no difference among the treatments in C/N ratio of the exception of OLF IV. In OLF IV total fruit weight was the highest as 1,558g per plant and total fruit number increased as 23.7% compared to control. The content of capsaicin in the ripened pepper increased with OLF I and II treatments, and decreased with OLF III and IV treatments compared to control of $662mg{\cdot}kg^{-1}$, but the soluble solid content was the highest with OLF IV treatment as $10.0^{\circ}Brix$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.5
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• pp.200-204
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• 2008

Mechano Chemical Process (MCP) skips the calcinations steps at an intermediate temperature that is always required in the conventional solid-state reaction because forming phase from raw powder is activated by mechanical energy. In this study, we prepared (Pb, La)$TiO_3$ nanopowder with perovskite structure by only high energy MCP. Especially, the PLT nanopowder was synthesized without any thermal treatment using oxides, not salts as raw powder. This process is also very simple due to dry milling method, unnecessary to dry of powder. The oxide powder was milled up to 12 hr at intervals of an hour using MCP and the pure PLT phase of perovskite structure was formed after milling time of 3 hr. And the average particle size was 20 nm with narrow distribution after milling time of 3 hr from raw powder of several $\mu m$ with inhomogeneous distribution.