• 약학회지
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• 제27권2호
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• pp.181-184
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• 1983

DMSO-oxalyl chloride at low temperature in methylene chloride reacted with isolated secondary hydroxyl groups in some monosaccharides to give alkoxysulfonium salts, convertible to carbonyls in high yields upon addition of triethylamine. And 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-allofuranose which is the key intermediate in the synthesis of 3-O-acetyl-5-O-benzoyl- 2-deoxy-2- fluoro-D-arabinofuranosyl bromide, was also obtained by oxidizing 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-glucofuranose with the oxidizing reagent, followed by reduction with sodium borohydride.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.613-616
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• 2003

Effect on hydrothermal treatment of lamellar vanadium oxides was investigated and the formation of hexagonal and cubic mesophase was found. This lamellar materials were prepared by mixing of cetyltrimethylammonium-bromide and pH-controlled sodium metavanadate solution. Thermal method and UV/O₃treatment were applied to extract organic template. The structure of resulting product was studied by powder X-ray diffraction and transmission electron microscopy (TEM).

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2619-2622
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• 2012

Bromination and iodination of the aromatic compounds have efficiently been carried out at room temperature and $70^{\circ}C$, respectively, in short reaction times using orthoperiodic acid/sodium bromide (1:2) and orthoperiodic acid/sodium iodide (1:2) in water to prepare the corresponding halo compounds with excellent yields.

• Fibers and Polymers
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• 제5권1호
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• pp.59-67
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• 2004

The development of high tenacity, high modulus monofilaments from Polypropylene/Clay nanocomposite has been investigated. Pure sodium montmorillonite nanoclay was modified using hexadecyl trimethyl ammonium bromide (HTAB) via an ion exchange reaction. Pure and modified clay were characterized through X-ray diffraction, FTIR and TGA. The modified clay was melt blended with polypropylene (PP) in presence of a swelling agent. Composite filaments from PP/Clay nanocomposite were prepared at different weight percentages of nanoclay and the spinning and drawing conditions were optimized. The filaments were characterized for their mechanical, morphological and thermal properties. The composite PP filaments with modified clay showed improved tensile strength, modulus and reduced elongation at break. The composite filaments with unmodified clay did not show any improvement in tensile strength but the modulus improved. The sharp and narrow X-ray diffraction peaks of PP/nanoclay composite filaments indicate increase in crystallinity in presence of modified clay at small loadings (0.5 %). The improved thermal stability was observed in filaments with modified as well as unmodified clays.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1310-1314
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• 2011

Sodium beta-alumina (SBA) nano-powders were synthesized by the citrate sol-gel process, and the effects of the cationic surfactant n-cetyltrimethylammonium bromide surfactant (CTAB) were investigated. The structure and morphology of the nano-powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM) techniques, respectively. The effects of CTAB on the citrate sol-gel process and the SBA formation were investigated by thermo gravimetric/differential thermal analysis (TG/DTA) and Fourier transform infrared spectroscopy (FTIR). The conductivity of ceramic pellets of SBA was measured by electrochemical impedance spectroscopy (EIS). The results showed that the CTAB inhibited the agglomeration of SBA powders effectively and consequently decreased the crystallization temperature of SBA, about $150^{\circ}C$ lower than that of the sample without CTAB. The measured conductivity of SBA was $1.21{\times}10^{-2}S{\cdot}cm^{-1}$ at $300^{\circ}C$.

• The Korean Journal of Pain
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• 제14권2호
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• pp.136-141
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• 2001

Background: Sodium salicylate (SS) is a nonsteroidal anti-inflammatory drug (NSAID) for the treatment of neuralgia or pain from rheumatoid arthritis. When abused or used in excess, SS can induce cytotoxicity. The present study examined whether SS has a neurotoxic effect. Methods: Cell viability was examined by MTT [3-(4,5-dimethylthiazol-2,5-dipheny ltetrazolium bromide] assay and Sulforhodamine (SRB) assay after cultivating dorsal root ganglion (DRG) neurons derived from neonatal mouse. These cells were treated with various concentrations of SS for 24 hours. In addition, the amount of protein synthesis against SS was measured in these cultures. Results: Cell viability (20, $40{\mu}g/ml$ SS) significantly decreased in a dose-dependent manner. Additionally, SS inhibited protein synthesis after the exposure of cultured mouse DRG neurons to $30{\mu}g/ml$ of SS for 24 hours. Conclusions: The present study suggests that SS is toxic in cultured DRG neurons derived from neonatal mouse by decreasing cell viability and the amount of protein synthesis.

• 폴리머
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• 제32권4호
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• pp.347-352
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• 2008

직접 중합법으로 내충격성 폴리스티렌(HIPS)과 유기화 점토로 구성된 나노복합재료를 합성하여 점토 첨가에 따른 물성을 조사하였다. 반응성 작용기를 갖는 유기화 점토인 vinylbenzyltrimethyl clay(VBC)와 octadecylvinylbenzyldimethyl clay(ODVC)를 sodium montmorillonite와 계면활성제인 vinylbenzyltrimethyl ammonium chloride(VBTMAC)와 octadecylyinylbenzdimethyl ammonium bromide(ODVBDAB)의 이온교환으로 각각 제조하였고 상용화된 유기화 점토인 $Cloisite^{(R)}$ 10A(C10A)를 비교를 위해 사용하였다. ODVD로 제조한 나노복합재료의 경우 X-선 회절(XRD) 피크가 사라진 것으로 보아 실리케이트 층이 박리된 것을 알 수 있었고, C10A로 제조한 나노복합재료의 경우 XRD 피크의 각도가 작은 쪽으로 이동하는 것으로 보아 실리케이트 층에 고분자 사슬이 층간 삽입된 것을 알 수 있었다. 저장탄성률과 복소점도로 나타낸 유변물성은 유기화 점토의 함량이 증가할수록 증가하였다.

• 공업화학
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• 제9권2호
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• pp.177-184
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• 1998

분체 형태의 소수성 고분자 polymethylmethacrylate(PMMA), poly vinyl chloride(PVC)와 친수성 금속 aluminium에 대한 water, glycerol, formamide, diiodomethane, 1,1,2,2-tetrabromoethane, 1-bromonaphthalene, acetone, chloroform, benzene, ethanol과 methanol과의 접촉각을 Washburn식을 기본으로 한 wicking법으로 측정하였다. 또한, 농도에 따른 음이온 계면활성제 SDS(sodium dodecyl sulfate)와 양이온 계면활성제 CTAB(cetyl trimethylamonium bromide) 수용액과의 접촉각을 측정하였다. 유기액체들과의 측정된 접촉각으로부터 Zisman plot을 사용하여 임계표면장력, ${\gamma}_c$를 예측하였으며, 농도에 따른 계면활성제 SDS와 CTAB수용액과의 접촉각으로부터 adhesion tension plot을 사용하여 ${\gamma}_c$를 예측하였다. 유기액체, 계면활성제 SDS와 CTAB수용액에 대해서 분체 PMMA의 ${\gamma}_c$는 각각 43.5, 28.3과 $36.2mNm^{-1}$이며, 분체 PVC의 ${\gamma}_c$는 각각 44.2, 28.0과 $34.8mNm^{-1}$값을 얻었다. 이로부터, 고체 표면의 적심성과 성질이 계면활성제의 첨가에 의해 변화됨을 알 수 있었다. 또한, 측정된 접촉각으로부터 조화평균식을 사용하여 각 고체의 표면자유에너지. ${\gamma}_s$와 그 성분 값들을 결정하였다.

• Journal of Pharmaceutical Investigation
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• 제36권3호
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• pp.161-167
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• 2006

The objective of this study was to investigate the dissolution patterns of variety of orally administered drug products available on the market. It aimed to understand their dissolution behaviors on the basis of the biopharmaceutics classification system (BCS) concept. On the tenets of BCS, several active pharmaceutical ingredients were selected: fluoxetine hydrochloride (class I), naproxen sodium (class ll), pyridostigmine bromide (class III), furosemide (class IV) and simvastatin (class IV). Typical dissolution media used in this study were pH 1.2, pH 4 & 6.8 phosphate buffers, and water. In cases, particular dissolution media specified in the KP and/or USP were used. Dissolution patterns of fluoxetine hydrochloride and pyridostigmine bromide products were characterized by their rapid release In addition, their dissolution characteristics were relatively unaffected by the type of a dissolution medium. Similar dissolution patterns were observed with pH 1.2, pH 4 & 6.8 phosphate buffers and water. By sharp contrast, poor dissolution patterns were noticed with naproxen sodium products, when pH 1.2 and pH 4 phosphate buffer were used. Improvements in its dissolution were achieved by switching the dissolution media to pH 6.8 phosphate buffer or water. Unsatisfactory dissolution data also were observed with a simvastatin product, when it was subject to dissolution tests by use of a surfactant-free pH 1.2, pH 4 & 6.8 phosphate buffers and water. All the release patterns reported in this study were best understood when BCS concepts were implemented. Our results demonstrated that a BCS-based drug classification should be considered first to choose a dissolution test/method and set up dissolution specification.

• 폴리머
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• 제25권3호
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• pp.414-420
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• 2001

유기화제의 종류에 따른 에폭시 나노복합재료에 미치는 영향을 연구하기 위하여, 알킬암모늄 염으로서 세틸트리메틸암모늄 브로마이드 (CTMA)와 알킬포스포늄 염으로서 세틸트리부틸포스포늄 브로마이드(CTBP)를 각각 Na-몬모릴로나이트에 삽입시켰다. 유기화제로서 CTMA로 치환된 MMT의 층간거리는 약 $18.8{\AA}$이였으며, CTBP로 치환되었을 경우 MMT의 층간거리 ($23.8 {\AA}$)는 CTMA로 치환되었을 경우 보다 증가하였다. 이것으로부터 MMT의 층간거리는 유기화제의 종류에 많은 영향이 있음을 알 수 있었다. 그리고 치환된 MMT의 열안정성은 유기화제의 종류에 영향이 있었으나, 이것으로부터 제조된 에폭시 나노복합재료의 경우는 아무런 영향이 없었다. 그리고 CTBP로 치환된 MMT로 제조된 에폭시 나노복합재료의 경우가 재료의 인장강도와 신장율이 CTMA로 치환된 MMT로부터 제조된 나노복합재료보다 증가하였다.