• 농약과학회지
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• 제9권3호
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• pp.274-277
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• 2005

살충제 펜피록시메이트는 4-hydroxyimino-5-phenoxypyrazole과 t-butyl 4-chloromethyl benzoate로부터 Williamson 합성을 통하여 합성되고 있다. 그러나 t-butyl benzoate 의 효과적인 합성방법은 여전히 문제점으로 남아있다. 본 연구에서는 t-butyl benzoate를 황산 촉매에서 t-butanol로부터 생성되는 isobutene을 사용하여 4-chloromethyl benzoic acid에 부가하여 합성하였다. 이 방법은 부산물의 생성없이 t-butyl 4-chloromethyl benzoate을 합성할 수 있어 기존에 보고된 방법보다 훨씬 용이하다. 따라서 본 연구는 펜피록시메이트를 대량으로 합성하는 효과적인 방법을 제시하였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.253-253
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• 2022

Codonopsis lanceolata (C. lanceolata) has been widely used in East Asia as a traditional medicine to treat various diseases such as bronchitis, convulsions, cough, obesity, and hepatitis. C. lanceolata belonging to Campanulaceae contains bioactive compounds such as polyphenols, saponins, and steroids. However, despite the pharmacological significance of C. lanceolata, the genetic information of this plant is limited and there are few studies of its transcriptome. In this study, we constructed a unigene set of C. lanceolata using Pac-Bio sequencing. Furthermore, the reads generated from Pac-bio and Illumina sequencing were mixed and assembled using rnaSPAdes. All genes involved in the triterpenoid pathway, a major bioactive compounds of C. lanceolata, were searched from the two unigene sets and the expression profiles of these genes were analyzed. The results showed that lupeol, beta-amyrin, and dammarenediol synthesis genes were activated in the leaves and roots of C. lanceolata. In particular, the expression of genes related to lupeol synthesis was relatively high, suggesting that the main triterpenoid of C. lanceolata is lupeol. Transcriptome studies related to lupeol synthesis in C. lanceolata have been rarely reported. Lupeol has been reported to have pharmacological effects such as anti-inflammatory, anti-cancer, and anti-bacterial. This study suggests the importance of C. lanceolata as a lupeol producing plant.

• Elastomers and Composites
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• 제54권4호
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• pp.279-285
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• 2019

Bio-based polyester polyols were synthesized using esterification with azelaic acid, sebacic acid, and 1,3-propanediol. Polyurethanes were prepared using chain extenders (1,4-Butanediol, 1,3-Propanediol, and isosorbide) and 4,4'-diphenylmethane diisocyanate with a mixing ratio of 1:1:1.1. Subsequently, the properties of the polymers prepared using the different chain extenders were compared. The synthesis of polyurethane was confirmed by FT-IR, TGA, and GPC. The mechanical properties (hardness, ball rebound, and tensile strength) of the materials were analyzed using shore A tester, taber abrasion, and UTM. heat, chemical, and water resistances of the prepared materials were measured by comparing the tensile strengths according to external changes.

• 한국분말재료학회지
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• 제13권6호
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• pp.432-438
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• 2006

Aluminum nitride (AlN) nanopowders with low degree of agglomeration and uniform particle size were synthesized by carbothermal reduction of alumina and subsequent direct nitridization. Boehmite powder was homogeneously admixed with carbon black nanopowders by ball milling. The powder mixture was treated under ammonia atmosphere to synthesize AlN powder at lour temperature. The effect of process variables such as boehmite/carbon black powder ratio, reaction temperature and reaction time on the synthesis of AlN nanopowder was investigated.

• 한국분말재료학회지
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• 제25권4호
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• pp.346-354
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• 2018

Over the last decade, the study of the synthesis of semiconductor colloidal quantum dots has progressed at a tremendous rate. Colloidal quantum dots, which possess unique spectral-luminescent characteristics, are of great interest in the development of novel materials and devices, which are promising for use in various fields. Several studies have been carried out on hot injection synthesis methods. However, these methods have been found to be unsuitable for large-capacity synthesis. Therefore, this review paper introduces synthesis methods other than the hot injection synthesis method, to synthesize quantum dots with excellent optical properties, through continuous synthesis and large capacity synthesis. In addition, examples of the application of synthesized colloid quantum dots in displays, solar cells, and bio industries are provided.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1578-1580
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• 2004

• 한국막학회:학술대회논문집
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• 한국막학회 2005년도 추계 총회 및 학술발표회
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• pp.165-165
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• 2005

• Advances in nano research
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• 제2권2호
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• pp.111-119
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• 2014

The chemical synthesis of anisotropic defective polyaniline/Ag composite (PANI/Ag) is explored using silver nitrate ($AgNO_3$) as the precursor material. This study provides a simple method for the formation of PANI/Ag nanocomposites at two different aniline concentrations $5{\mu}l$ (PANC5) and $10{\mu}l$ (PANC10). The composite PANC5 exhibits UV-Visible absorption peaks at 436 nm and 670 nm whereas, PANC10 exhibits absorption peaks at 446 nm and 697 nm. This shift is caused by the strong interaction between polyaniline and silver. The characterized FTIR peaks observed at around $3410cm^{-1}$ (PANC5) and $3420cm^{-1}$ (PANC10) was due to the N-H stretching vibrations. The appearance of a broad band instead of a sharp peak can be attributed due to the presence of a high concentration of N-H groups in the nanocomposite. The TEM images show that the sample contains defective spherical, truncated triangular and rod shaped particles. The results showed that the PANI/Ag nanocomposites are composed of nano-sized particles of 43-53 nm that contain Ag domains of 33-37 nm with polymer thickness 5.7-11.2 nm at two different aniline concentrations.

• 생약학회지
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• 제52권2호
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• pp.84-91
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• 2021

This study was carried out to investigate the melanin synthesis inhibitory effect of Aspergillus fumigatus fermented extract. In this study, we revealed the effects of A. fumigatus fermented extract on melanin contents, mushroom tyrosinase activity, and expression levels of mRNA and proteins of melanogenesis-related gene in B16F10 melanoma cells. A. fumigatus fermented extract inhibited both melanin contents and tyrosinase activity. In addition, the expression level of mRNA or proteins of melanogenesis was down-regulated in the A. fumigatus fermented extract treated B16F10 cells with dose-dependent manner. Moreover, when the clinical test was conducted, it was confirmed that the use of the fermented extract of A. fumigatus for 8 weeks improved skin brightness 1.586 times brighter and skin melanin 1.331 times better compared to the control product. Taken together, our results suggest that A. fumigatus fermented extract has melanogenesis inhibitory effect and whitening activity, thus it showed the possibility for using as a functional whitening cosmetic resource.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.951-956
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• 2001

A 28-kDa extracellular lipase (pI 8.7) was purified to homogeneity from the culture supernatant of Trichosporon sp. Y- 11 by mmonium sulfate precipitation, DEAE-Sephadex A-50, Bio-Gel P-30, CM- Sephadex C-50, and Bio-Gel P- 10 chromatographies. The purified enzyme exhibited a specific activity of $2,741{\;}{\mu}mol/min/mg$ based on the hydrolysis of triolein, and the optimal hydrolysis activity was dentified at pH 8.0 and $40^{\circ}C$. The enzyme activity was inhibited by $Ag^+$ and enhanced by $Fe^{2+}$, $Fe^{3+}$, $Mg^{2+}$, $Mn^{2+}$, and $Li^{+}$. The enzyme activity exhibited for the hydrolysis of both tributyrin and trilinolein. The ester synthesis of unsaturated fatty acids with various alcohols catalyzed by the purified lipase in a nonaqueous medium or microaqueous system was also investigated. The esterification activity of the lipase increased with an increase of the carbon chain length in the alcohol. The synthesis rate of linoleic acid and oleyl alcohol was the highest with an optimal temperature and pH of $40^{\circ}C$ and 8.0, respectively. The water content and agitation also affected the esterification activity of the lipase.