• Natural Product Sciences
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• v.18 no.3
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• pp.147-152
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• 2012

Ergosta-4,6,8(14),22-tetraen-3-one (1), ergosta-7,24(28)-dien-3-ol (2), and 5,8-epidioxyergosta-6,22-dien-3-ol(3) were isolated from the fruit body of Phellinus pini. Their structures were based on spectroscopic methods including IR, MS, and NMR (1D and 2D). These compounds were screened for their ability to inhibit nitric oxide (NO) production in LPS-activated RAW 264.7 cells. Compounds 1, 2, and 3 reduced NO production in the assay with $IC_50$ values of 29.7 ${\mu}M$ (1), 15.1 ${\mu}M$ (2), and 18.4 ${\mu}M$ (3) respectively. They also suppressed the expression of protein and m-RNA of iNOS and COX-2 in a dose dependent manner by western blot analysis and RT-PCR experiment in LPS-activated microglial cells.

• Bulletin of the Korean Chemical Society
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• v.13 no.1
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• pp.26-29
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• 1992

Copolymers with two different side groups, 2,2,2-trifluoroethoxy and p-chlorophenoxy groups, have been synthesized by reaction of poly(dichlorophosphazene) with their sodium salts, and characterized by elemental analysis, gel permeation chromatography, IR and NMR spectroscopies. The molecular weight measurement has shown that the weight average molecular weight, ${\bar{M}}_w$ of the copolymers are all above $10^6$ and their molecular weight distributions are monomodal and narrow (${\bar{M}}_w/{\bar{M}}_n<4$). Thermal properties of these copolymers measured by DSC and TGA exhibited to be intermediate between those of the two corresponding homopolymers.

• YAKHAK HOEJI
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• v.29 no.2
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• pp.96-102
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• 1985

Innovated utilization of Korean kaolins as pharmaceuticals is attempted, for which relevant properties including adsorptive behaviours are observed in connection with their mineralogical structures. In practice, physico-chemical properties are assessed by means of IR, XRD and thermal analysis including DTA, TG and DSC. Elemental analysis of the ore specimens under investigation is carried out in conventional manners. It is found that the chemical compositions are varied significantly with sampling sites and primary classifications. The clay ores thus analyzed are mainly composed of halloysite species. Proper benefication of the raw clays is necessary so that authentic requirements for medicinal use may be satisfied. White-colored premium grade halloysite could be utilized as therapeutics with relative ease after purification. Evidence indicates that gibbsite-like impurities are intercalated between the 1 : 1 layered moieties. Thermal behaviours may be characterized in such a fashion that loss of free water occurs near 100.deg. C and further heatings result in liberation of bound water near 500.deg. C, with subsequent transformation into amorphous metastable entities. Through thermal activation, enhanced pharmaceutical effects could be envisaged.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.22-22
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• 2021

큰졸방제비꽃(Viola kusanoana)의 엽록체 DNA 염기서열을 밝히고자 차세대염기서열분석법(NGS)을 이용하여 분석하였다. 재료는 경상북도 울릉군 나리분지에 자생하는 개체의 잎을 사용하였다. 염기서열 분석결과, 총 길이는 158,644 bp 였고, GC함량은 36.3%로 분석되었다. 구간별로는 LSC (Large single copy)지역이 86,999 bp (GC content: 33.9%)였고 SSC (Small single copy)지역은 17,439 bp (GC content: 29.9%)으로 분석되었으며 IR (Invertied repeats)지역은 27,103 bp (GC content: 42.2%)로 확인되었다. 유전자는 protein coding gene 77개, tRNA gene 30개, rRNA 4개 등 총 111개로 이는 선행 연구된 제비꽃속 8개 분류군과 유전자의 순서와 방향이 모두 일치하였다. 이를 통해 제비꽃속의 엽록체 게놈의 유전자는 상당히 보존되어 있음을 확인하였다.

• Journal of the Korean Physical Society
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• v.80
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• pp.20-29
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• 2022

We discuss various aspects of anisotropic gravity in (d+D)-dimensional spacetime, where D dimensions are treated as extra dimensions. It is based on the foliation preserving diffeomorphism invariance and anisotropic conformal invariance. The anisotropy is embodied by introducing a factor z which discriminates the scaling degree of the extra D dimensions against the d-dimensional base spacetime and Weyl scalar field which mediates the anisotropic scaling symmetry. There is no intrinsic scale but a physical scale M_* emerges as a consequence of spontaneous conformal symmetry breaking. We discuss interesting lower dimensional gravity theories obtained from our model. In a (d, D) = (2, 2) case, we suggest a UV-complete unitary quantum gravity which might become Einstein gravity in IR. In a certain (2,1) case, we obtain CGHS model. Some vacuum solutions are also obtained and we discuss an issue of 'size separation' between the base spacetime and the extra dimensions. The size separation means large distinction between the scales (e.g. cosmological constant) appearing in the base spacetime and the extra dimensions respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.36.2-36.2
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• 2009

Low dielectric materials have been great attention in the semiconductor industry to develop high performance interlayer dielectrics with low k for Cu interconnect technology. In our study, the dielectric properties of SiOC /SiO2 thin film derived from polyphenylcarbosilane were investigated as a potential interlayer dielectrics for Cu interconnect technology. Polyphenylcarbosilane was synthesized from thermal rearrangement of polymethylphenylsilane around $350^{\circ}C{\sim}430^{\circ}C$. Characterization of synthesized polyphenylcarbosilane was performed with 29Si, 13C, 1H NMR, FT-IR, TG, XRD, GPC and GC analysis. From FT-IR data, the band at 1035 cm-1 is very strong and assigned to CH2 bending vibration in Si-CH2-Si group, indicating the formation of the polyphenylcarbosilane. Number average of molecular weight (Mn) of the polyphenylcarbosilane synthesized at $400^{\circ}C$ for 6hwas 2, 500 and is easily soluble in organic solvent. SiOC/SiO2 thin film was fabricated on ton-type silicon wafer by spin coating using 30wt % polyphenylcarbosilane incyclohexane. Curing of the film was performed in the air up to $400^{\circ}C$ for 2h. The thickness of the film is ranged from $1{\mu}m$ to $1.7{\mu}m$. The dielectric constant was determined from the capacitance data obtained from metal/polyphenylcarbosilane/conductive Si MIM capacitors and show a dielectric constant as low as 2.5 without added porosity. The SiOC /SiO2 thin film derived from polyphenylcarbosilane shows promising application as an interlayer dielectrics for Cu interconnect technology.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.579-598
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• 2019

We investigated geochemical contaminants and Fe, Al behavior in precipitates of acid mine drainage (AMD) from the Donghae abandoned coal mine, Taebaek, Gangwon Province using aqueous chemical analyses, XRD, IR, and ²⁷Al NMR, Our results showed that water chemistry changed with pH and Eh, and saturation indices of chemical species in the AMD. According to saturation calculated by visual MINTEQ, the AMD was saturated with various Fe-, Al-oxyhydroxide minerals. Reddish brown precipitates are composed of schwertmannite, ferrihydrite, and goethite, whereas whitish precipitates are composed mostly of alumimous minerals such as poorly crystallized basaluminite with trace Al₁₃-Tridecamer. It is important to apply active treatment methods rather than simple storage pond and to control the precipitation and solubility of iron species and aluminous species for ensuring remediation and control for the AMD discharged from the Donghae abandoned coal mine.

• The Korean Journal of Mycology
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• v.29 no.1
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• pp.67-71
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• 2001

A steroid compound, F-l with antioxidative activity from the fruit bodies of Fomitella fraxinea was isolated by ethyl acetate extraction, silica gel column chromatography, and preparative silica thin layer chromatography. The structure of the compound was determined to be crgosta-7,22-diene-3-one-$16{\beta}-ol$ by IR, NMR, and GC-Mass. The compound exhibited inhibition on lipid peroxidation of rat liver microsomes, with $IC_{50}$ value of $3.8{\mu}g/ml$.

• Polymer(Korea)
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• v.29 no.3
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• pp.253-259
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• 2005

Polyurethanes, synthesized by polyester polyols and aliphatic or aromatic diisocyanates for a crease resist finishing agent, were prepared by two-step reactions, that is, prepolymer synthesis and chain extension. The structures of synthesized polyurethanes were confirmed by the measurement of FT-IR and $^1H$-NMR spectrometer. The number average molecular weight ($\bar{M}_n$) and the weight average molecular weight ($\bar{M}_w$) of the polyurethane with aromatic diisocyanate (MDI) were higher than those of the synthesized polyurethanes with aliphatic diisocyanate (HDI, $H_{12}MDI$). The glass transition temperatures ($T_g$) of soft segments in polyurethanes with MDI, HDI, $H_{12}MDI$ were -25,-42 and -50$^{circ}C$, respectively. In the polyurethanes obtained by two-step reaction, thermal stability and tensile strength increased with increasing hard segment contents, whereas elongation at break decreased with increasing hard segment contents.

• Korean journal of applied entomology
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• v.19 no.1 s.42
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• pp.51-55
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• 1980

The study has been carried to confirm pathogenesity among the isolates which obtained from leaf blight type symptoms and Kresek type symptoms, and also to observe varietal resistance among 29 varieties and/or lines through the introduction of two different pathotypes, of Xanthomonas oryzae, by the use of root clipping and pin prick methods. There was no significant differences among the isolates when their growth in plant tissue were compared. There was certain tendency, however, that the isolates from Kreseked plants showed longer lesion than those from blight type lesions. Both isolates from blight type and Kresek type induced the same degree of Kresek syptoms when they were introduced into plants by root cutting in the suspension prior to transplant. Varietal resistance to 'Kresek' appeared to be the same with those on leaf blight type though Wase Aikoku group varieties showed Kresek symptoms which is not the case with leaf blight type. IR 20 in Kogyoku group varieties showed highly resistant reaction to Kresek type. Root clipping method induced the more of Kresek than those by pin pricking method.