• Proceedings of the Korea Association of Crystal Growth Conference
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• 2000.06a
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• pp.59-64
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• 2000

Silicon nitride ceramics with various α/β phase ratio were fabricated by controlling sintering conditions of PECS process. Mechanical properties varied systematically with α/β ratio. Young's modulus and hardness increased with α-Si₃N₄ volume fraction, and fracture strength and toughness increased with β-Si₃N₄ content.

• Toxicological Research
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• v.13 no.3
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• pp.197-202
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• 1997

Kyoaesamultang(KAT) has been used as an important prescription for various diseases including threatened abortion, associated with pregnancy in traditional medicine. In oder to identify the safety of KAT, this study was designed to determine mutagenicity and hepato-toxicity. In Rec-assay, Bacillus subtills H-17($Rec{^+}$) and M-45($Rec{^-}$) strains were used to clarify the DNA damage property. In Ames test, Salmonella typhimurium TA98 and TA100 were used for mutagenicity testing. In SOS umu test, Salmonella typhimurium TA1535 containing plasmid pSK1002 was used as a tester strain, and the levels of umu operon expression were monitored by measuring the $\beta$-galactosidase activity. From tested results, KAT did not show DNA damage and mutagenicity. On the other hand, hepato-toxicity of KAT to female ICR mice was monitored by the measurements of s-GOT, s-GPT and LDH activities after oral feeding for 15days. KAT showed 34% increase of s-GOT and s-GPT activities, also exhibited 35% increase of LDH activity in mice sera.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.32.2-32.2
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• 2010

Red dusty Active Galactic Nuclei (AGNs) are suspected to mid-stage between ULIRG and AGN phase. As well as, they are suspected that they have more than 50% of AGN population. To understand character of red AGN, Black Hole (BH) mass of red AGN is a key property and haven't measured by existing method such as reverberation mapping and single epoch method. So we still don't know their character and properties clearly. To estimate properties of red AGNs escape from effect of dust-obscuration, we have obtained Near InfraRed (NIR) spectra of 31 reverberation mapped AGNs and 49 Palomar-Green(PG) Quasi-Stellar Object (QSO) using the infrared camera (IRC) for AKARI with unique wavelength range 2.5-$5.0{\mu}m$. From this spectra, we measured the FWHM and luminosity of brackett ${\alpha}$, ${\beta}$ at 4.0, 2.6 micron meter for deriving new BH mass estimators based on the properties of Brackett line emission.

• Carbon letters
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• v.16 no.2
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• pp.101-106
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• 2015

We report a covalent functionalization of graphene nanoparticles (GnPs) employing 2,3,4-Tri-O-acetyl-${\beta}$-D-xylopyranosyl azide followed by fabrication of an epoxy/functionalized graphene nanocomposite and an evaluation of its thermo-mechanical performance. Successful functionalization of GnP was confirmed via thermal and spectroscopic study. Raman spectroscopy indicated that the functionalization was on the edge of the graphene sheets; the basal plane was not perturbed as a result of the functionalization. The epoxy/functionalized GnP composite system exhibited an increase in flexural modulus (~18%) and glass transition temperature (${\sim}10^{\circ}C$) compared to an un-functionalized GnP based epoxy composite.

• Microbiology and Biotechnology Letters
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• v.28 no.1
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• pp.59-61
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• 2000

The various extracellular enzymes produced by lactic acid bacteria isolated from kimchi were assayed to improve the shelf-life of kimchi. Peroxidase was not detected in all tested lactic acid bacteria and small amount of ascorbic acid oxidase was detected in Pediococcus pentosaceus and Lactobacillus brevis. In case of $\alpha$-amylase, 27.8 and 20.9 unit/mg were shown in Pediococcus acidilactici and Pediococcus pentosaceus, respectively but $\beta$-amylase and protease activities were very low. The enzyme related to textural property of kimchi, pectinesterase showed low activity but polygalacturonase activity was 0.28 unit/mg in Lactobacillus homohiochii and 0.27 unit/mg in Lactobacillus plantarum.

• Natural Product Sciences
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• v.16 no.4
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• pp.228-232
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• 2010

Bioactivity-guided fractionation using on-line HPLC biochemical detection system on $CHCl_3$-soluble fraction of Lycoris radiata led to the isolation of deoxylycorenine (1), O-demethylhomolycorine (2), galanthamine (3), lycoramine (4), mixture of $6{\alpha}$-and $6{\beta}$-haemanthidine (5), and lycorine (6), identified by spectroscopic data and physicochemical property. Among the isolated compounds, 1, 3 and 6 showed acetylcholinesterase inhibitiory activities with $IC_{50}$ values of 18.0, 12.0 and $16.6\;{\mu}M$, respectively, in in vitro colorimetric microplate assay.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.430-439
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• 2016

Medicine herb residues boards were manufactured by using medicine herb residues, and emission properties of volatile compounds from boards were examined under various temperature conditions. The volatile compounds were identified with analysis of TD GC/MS by absorbing their flavor components in Tenax tubes. Total 88 volatile compounds were identified from the board. The number of identified compounds at temperature conditions of $25^{\circ}C$, $35^{\circ}C$, and $45^{\circ}C$ were 44, 55, and 65 kinds, respectively. The number of volatile compounds and the total peak area tended to increase with an increase in the temperature. The number of the flavor components detected in all temperature conditions were 34 kinds. Hydrocarbon compounds showed 93% of the detected flavor compounds at $25^{\circ}C$, 92% at $35^{\circ}C$, and 90% at $45^{\circ}C$. Ether compounds accounted for 4% and ketone, aldehyde, and acid-type compounds were detected in a small quantity. The hydrocarbons were composed of 17 kinds of monoterpenes and 39 kinds of sesquiterpenes, which accounted for 11% and 80%, respectively. The most detected compound of monoterpene was limonene, and the major flavor components of sesquiterpenes were ${\alpha}-curcumene$, zingiberene, ${\beta}-elemene$, ${\beta}-selinene$, ${\alpha}-amorphene$, and ${\alpha}-copaene$. Anethole (3.26%) known for ether compounds was detected considerably in all temperature conditions. The results suggest that the manufactured medicine herb residues board include various types of flavor compounds and the flavor compounds might be useful for the manufacture of various products.

• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.163-170
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• 2008

Purpose: Biphasic calcium phosphates have been of great interest recently. Mixing adequate ratios of hydroxyapatite(HA) and beta-tricalcium phosphate($\beta$-TCP) allowed to control the resorption rate without distorting its osteoconductive property. This study evaluated the bone formation effect of newly developed biphasic calcium phosphate(BCP) in calvarial defect of rabbits. Materials and Methods: 6 male New Zealand rabbits were used. Four defects with 8mm in diameter were created on each animal. BCP with HA/$\beta$-TCP ratio of 7:3 and particle size of $0.5{\sim}1.0\;mm$ was used as the test group and bovine bone with $0.25{\sim}1.0\;mm$ particle size, as the control group. Both test and control group materials were randomly implanted in the calvarial defects and were covered witha polymer membrane. The animals were sacrificed after 12, 24, and 48 weeks of implantation under general euthanasia. Resin blocks were obtained and were stained by masson's trichrome for histological observation. Results: Overall results were uneventful without any defect exposure or inflammation. The amount of new bone formation and bone maturity increased with increase in healing period at both groups. New bone in test group was mostly formed along the material particle surrounded by osteoblasts, and observation of osteoblastic stream was also present. Bone maturity increased as it was closer to thedefect margins. Under the same healing period, the test group showed more bone formation than the control group with more stable bovine bone particles remaining even after 48 weeks, whereas considerable resorption took place in BCP. Almost total defect closure was observed in test group with new bone formation in the central part of the defect. However, limited new bone formation was observed in the control group. Conclusion: Within the limits of the study, the present study reveals the newly developed BCP to be a good osteoconductive material. However, further studies are needed to be conducted in a different study model with a larger sample size.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.206-213
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• 2008

We observed the physical and chemical properties of a soil on pine mushroom picking areas where were located in the most upper and lower parts showing a comparative climatic characteristics in Korea. The slope gradients within the investigation areas which were divided into 100 quadrates of $1m^2$ ranged from $5.7{\sim}8.6{\beta}$ to $24{\sim}22.7{\beta}$ (left to right) and $4.5{\sim}6.8{\beta}$ to $13.5{\sim}17.8{\beta}$ (top to bottom) for Ponghwa and Gansung, respectively. The amount of clay and thickness of organic matter were significantly decreased with increasing slope gradient, resulting in decrease of the soil moisture content around a fairly ring-colony of Tricholoma matsutake which was observed under the relatively thicker organic matter layer beyond 3 cm depth. Soil pHswere weak acid and average EC was $0.44dS\;m^{-1}$ in both areas. The cations were in the order of Fe K > Na > Mg > Ca and Fe > K > Na > Ca > Mg for the upper(Gansung) and the lower (Ponghwa) part. And the amount of Fe was approximately $80dS\;m^{-1}$ or greater in the pine mushroom picking soil. From this, we could assume that the growth of the pine mushroom was closely related not only with iron but also soil moisture content.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.902-908
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• 2006

Tetrandra is the root of Stephania tetrandra 5. Moore (family Menispermaceae), or of Aristolochia frangchi Wu (family Aristolochiaceae). It is a Differ-flavored and cold-property herb acting on the urinary bladder, kidney and spleen meridiands. Known biological effects of this herb are expelling wind to relieve pain and inducing diuresis to alleviate edema. This herb also has anti-inflammatory and anti-hypersensitivity actions. Recent studies have shown that Stephanniae Tetrandrae Radix has antimicrobial effects, namely, a protective effect on acute renal failure induce by gentamicin sulfate and a suppressive effect against clostridium perfringes. However, there is a lack of studies concerning the immunological activities of this herb. The present study was conducted to evaluate the immunological activities of Stephanniae Tetrandrae Radix on the regulatory mechanisms of cytokines and nitric oxide (NO) in Raw 264.7 cells. Cell viability was measured by MTT assay after the treatment of Stephanniae Tetrandrae Radix extract (STRE) and NO production was monitored by measuring the nitrite content in culture medium. COX-2 and iNOS were determined by immunoblot analysis, and levels of cytokine were analyzed by sandwich immunoassays. Results provided evidences that STRE inhibited the production of nitrite and nitrate (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$, $interleukin-1{\beta}(IL-1{\beta})$ and interleukin-6 (IL-6) in Raw 264.7 cells activated with lipopolysaccharide (LPS). These findings showed that STRE could produce some anti-inflammatory effects which might play a role in adjunctive therapy in Gram-negative bacterial infections.